From jorvis at gmail.com  Fri May  3 14:54:26 2013
From: jorvis at gmail.com (jorvis at gmail.com)
Date: Fri, 3 May 2013 11:54:26 -0700 (PDT)
Subject: pycache directories
In-Reply-To: <841fcc01-df05-4a8b-8b4f-1217c49aac44@googlegroups.com>
References: <841fcc01-df05-4a8b-8b4f-1217c49aac44@googlegroups.com>
Message-ID: <dabbde1c-3a07-461f-ab81-e09e5a57810b@googlegroups.com>

I agree, this would be a good feature.  I redirect my emacs backups to a single directory too so that they're not distributed all over the file system.  While I don't know how to do that with the things python creates, I've read a few ways you can disable their creation altogether (assuming you don't care or need the benefit of their use):

You can run python with -B or set the environmental variable PYTHONDONTWRITEBYTECODE=1

For fun, lots of developer discussion about its original creation here:

http://www.gossamer-threads.com/lists/python/dev/815510


From nikos.gr33k at gmail.com  Sun May 26 16:48:47 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 13:48:47 -0700 (PDT)
Subject: This mail never gets delivered. Any ideas why?
In-Reply-To: <531b6ec4-2782-4886-bbfe-a395752c026f@googlegroups.com>
References: <fdc2a4d2-1967-4906-907e-3cf121694549@googlegroups.com>
	<c7fe4276-8ecf-4229-94e1-9b95a49f549a@googlegroups.com>
	<10f30df1-e0f8-4834-ae5f-b6e0d0aac079@googlegroups.com>
	<513c209d$0$6512$c3e8da3$5496439d@news.astraweb.com>
	<3daebceb-88e2-4d0b-bc32-802e6cece93e@googlegroups.com>
	<513c624c$0$6512$c3e8da3$5496439d@news.astraweb.com>
	<08433d4e-6ffb-4929-a708-f8ba1d670449@googlegroups.com>
	<khlm6b$i7g$1@r03.glglgl.gl>
	<531b6ec4-2782-4886-bbfe-a395752c026f@googlegroups.com>
Message-ID: <6a94ee23-f0f6-470c-a927-0d6bb35a3114@googlegroups.com>

I'am receiving this now after some tries:

A problem occurred in a Python script. Here is the sequence of function calls leading up to the error, in the order they occurred.

 /home/nikos/public_html/cgi-bin/metrites.py in ()
    139         else:
    140                 sp = subprocess.Popen(['mail', '-f', FROM, '-s', 'Mail from Guest', 'support at superhost.gr'], stdin=subprocess.PIPE)
=>  141                 sp.communicate( MESSAGE )
    142                 status = sp.wait()
    143                 if status:
sp = <subprocess.Popen object>, sp.communicate = <bound method Popen.communicate of <subprocess.Popen object>>, MESSAGE = 'kdsjfksdjkfjksdjfs\r\n\t'
 /opt/python3/lib/python3.3/subprocess.py in communicate(self=<subprocess.Popen object>, input='kdsjfksdjkfjksdjfs\r\n\t', timeout=None)
    901                 if input:
    902                     try:
=>  903                         self.stdin.write(input)
    904                     except IOError as e:
    905                         if e.errno != errno.EPIPE and e.errno != errno.EINVAL:
self = <subprocess.Popen object>, self.stdin = <_io.BufferedWriter name=5>, self.stdin.write = <built-in method write of _io.BufferedWriter object>, input = 'kdsjfksdjkfjksdjfs\r\n\t'
TypeError: 'str' does not support the buffer interface 
      args = ("'str' does not support the buffer interface",) 
      with_traceback = <built-in method with_traceback of TypeError object>


From cs at zip.com.au  Sun May 26 20:22:29 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 27 May 2013 10:22:29 +1000
Subject: This mail never gets delivered. Any ideas why?
In-Reply-To: <6a94ee23-f0f6-470c-a927-0d6bb35a3114@googlegroups.com>
References: <6a94ee23-f0f6-470c-a927-0d6bb35a3114@googlegroups.com>
Message-ID: <20130527002229.GA12740@cskk.homeip.net>

On 26May2013 13:48, =?utf-8?B?zp3Or866zr/PgiDOk866z4EzM866?= <nikos.gr33k at gmail.com> wrote:
| I'am receiving this now after some tries:
| 
| A problem occurred in a Python script. Here is the sequence of function calls leading up to the error, in the order they occurred.
| 
|  /home/nikos/public_html/cgi-bin/metrites.py in ()
|     139         else:
|     140                 sp = subprocess.Popen(['mail', '-f', FROM, '-s', 'Mail from Guest', 'support at superhost.gr'], stdin=subprocess.PIPE)
| =>  141                 sp.communicate( MESSAGE )
|     142                 status = sp.wait()
|     143                 if status:
| sp = <subprocess.Popen object>, sp.communicate = <bound method Popen.communicate of <subprocess.Popen object>>, MESSAGE = 'kdsjfksdjkfjksdjfs\r\n\t'
|  /opt/python3/lib/python3.3/subprocess.py in communicate(self=<subprocess.Popen object>, input='kdsjfksdjkfjksdjfs\r\n\t', timeout=None)
|     901                 if input:
|     902                     try:
| =>  903                         self.stdin.write(input)

Well, you should probably be writing to sp.stdin, not sys.stdin.

|     904                     except IOError as e:
|     905                         if e.errno != errno.EPIPE and e.errno != errno.EINVAL:
| self = <subprocess.Popen object>, self.stdin = <_io.BufferedWriter name=5>, self.stdin.write = <built-in method write of _io.BufferedWriter object>, input = 'kdsjfksdjkfjksdjfs\r\n\t'
| TypeError: 'str' does not support the buffer interface 
|       args = ("'str' does not support the buffer interface",) 
|       with_traceback = <built-in method with_traceback of TypeError object>

This is symptomatic of sys.stdin (well, whatever you're writing to)
being open in binary mode instead of text mode. And you're passing
a str. Try passing std.encode().

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Yes, [congress is] petty and venal and selfish.  That's why they're called
_representatives_.      - Will Durst


From cs at zip.com.au  Sun May 26 20:28:09 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 27 May 2013 10:28:09 +1000
Subject: This mail never gets delivered. Any ideas why?
In-Reply-To: <20130527002229.GA12740@cskk.homeip.net>
References: <20130527002229.GA12740@cskk.homeip.net>
Message-ID: <20130527002809.GA28797@cskk.homeip.net>

On 27May2013 10:22, I wrote:
| | =>  903                         self.stdin.write(input)
[...]
| | self = <subprocess.Popen object>, self.stdin = <_io.BufferedWriter name=5>, self.stdin.write = <built-in method write of _io.BufferedWriter object>, input = 'kdsjfksdjkfjksdjfs\r\n\t'
| | TypeError: 'str' does not support the buffer interface 
| |       args = ("'str' does not support the buffer interface",) 
| |       with_traceback = <built-in method with_traceback of TypeError object>
| 
| This is symptomatic of sys.stdin (well, whatever you're writing to)
| being open in binary mode instead of text mode. And you're passing
| a str. Try passing std.encode().

Sorry, that should be "input.encode()".
-- 
Cameron Simpson <cs at zip.com.au>

PCs are like a submarine, it will work fine till you open Windows. - zollie101


From nikos.gr33k at gmail.com  Mon May 27 01:00:15 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 22:00:15 -0700 (PDT)
Subject: This mail never gets delivered. Any ideas why?
In-Reply-To: <mailman.2225.1369614504.3114.python-list@python.org>
References: <20130527002229.GA12740@cskk.homeip.net>
	<mailman.2225.1369614504.3114.python-list@python.org>
Message-ID: <6f870aa1-8a94-4510-a466-ca48e0605d9f@googlegroups.com>

else:
		sp = subprocess.Popen(['mail', '-f', FROM, '-s', 'Mail from Guest', 'support at superhost.gr'], sp.stdin=subprocess.PIPE)
		sp.communicate( input.encode(MESSAGE, 'utf-8') )
		status = sp.wait()


this gives me an internal server error Cameron, but i guess iam writing it wrong.

Thsi though doesnt provide an error:

	else:
		sp = subprocess.Popen(['mail', '-f', FROM, '-s', 'Mail from Guest', 'support at superhost.gr'], stdin=subprocess.PIPE)
		sp.communicate( bytes( MESSAGE, 'utf-8' ) )
		status = sp.wait()

but neither gets the mail across.


From nikos.gr33k at gmail.com  Mon May 27 05:15:12 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Mon, 27 May 2013 02:15:12 -0700 (PDT)
Subject: This mail never gets delivered. Any ideas why?
In-Reply-To: <6f870aa1-8a94-4510-a466-ca48e0605d9f@googlegroups.com>
References: <20130527002229.GA12740@cskk.homeip.net>
	<mailman.2225.1369614504.3114.python-list@python.org>
	<6f870aa1-8a94-4510-a466-ca48e0605d9f@googlegroups.com>
Message-ID: <2f789ce5-b493-4ee4-95c4-0e8885978259@googlegroups.com>

Please, do you see an error in this?
As i said the 2nd solution doesnt provide an error but also doesn't get the mail send too.


From breamoreboy at yahoo.co.uk  Mon May 27 07:44:21 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 27 May 2013 12:44:21 +0100
Subject: This mail never gets delivered. Any ideas why?
In-Reply-To: <2f789ce5-b493-4ee4-95c4-0e8885978259@googlegroups.com>
References: <20130527002229.GA12740@cskk.homeip.net>
	<mailman.2225.1369614504.3114.python-list@python.org>
	<6f870aa1-8a94-4510-a466-ca48e0605d9f@googlegroups.com>
	<2f789ce5-b493-4ee4-95c4-0e8885978259@googlegroups.com>
Message-ID: <knvgu3$1h2$1@ger.gmane.org>

On 27/05/2013 10:15, ????? ???33? wrote:
> Please, do you see an error in this?
> As i said the 2nd solution doesnt provide an error but also doesn't get the mail send too.
>

At least you're improving.  Yesterday you were chasing after two hours, 
it's now up to four hours 15 minutes.  Keep doubling the time like this 
and you'll soon be up to the 24 hours that's considered polite.  As 
previously stated the time can be shortened substantially by getting 
your cheque book out.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From dreamingforward at gmail.com  Wed May  8 22:35:58 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Wed, 8 May 2013 19:35:58 -0700
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
Message-ID: <CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>

On Fri, Apr 12, 2013 at 11:28 PM, Mark Janssen
<dreamingforward at gmail.com> wrote:
>> Mark, this proposal is out of place on a Python list, because it proposes an
>> object methodology radically different from any that is implemented in
>> Python now, or is even remotely likely to be implemented in Python in the
>> future.
>
> Wow, you guys are a bunch of ninnies.  I'm going to find some
> theoretical folks....

Okay, to anyone who might be listening, I found the core of the problem.

This issue is/was much deeper than OOP (which would be roughly a 20
year refactoring) -- that was my mistake.  The issue goes right to the
core to models of computation and the historical factions within
theoretical CS itself (a 50+ year refactoring).

The field needs re-invented and re-centered.  Mark my words.  There
has been a half-century of confusion between two entirely separate
domains and they've been using the same lexicon.  Long story short:
the lambda calculus folks have to split from the Turing machine folks.
 These models of computation should not use the same language.  Their
computation models are too radically different.  Lisp will remain a
pinnacle of the lambda calculus, but should be remanded to philosophy.
 The logic of the binary/boolean arithmetic is simply not compatible,
but forms the basis of any sensible computer science here in the West.

Here pronouncith the.... whatever

-- 
MarkJ
Tacoma, Washington


From dreamingforward at gmail.com  Wed May  8 22:39:03 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Wed, 8 May 2013 19:39:03 -0700
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
Message-ID: <CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>

> ...The field needs re-invented and re-centered.[...]

For anyone who want to be involved.  See the wikiwikiweb -- a tool
that every programmer should know and use --  and these pages:
ComputerScienceVersionTwo and ObjectOrientedRefactored.

Cheers!
-- 
MarkJ
Tacoma, Washington


From ned at nedbatchelder.com  Sun May 12 13:18:58 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Sun, 12 May 2013 13:18:58 -0400
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>
Message-ID: <518FCF02.9090307@nedbatchelder.com>

On 5/8/2013 10:39 PM, Mark Janssen wrote:
>> ...The field needs re-invented and re-centered.[...]
> For anyone who want to be involved.  See the wikiwikiweb -- a tool
> that every programmer should know and use --  and these pages:
> ComputerScienceVersionTwo and ObjectOrientedRefactored.

I've never understood why people use that site: the pages end up being 
unintelligible cocktail-party noise-scapes with no hope of understanding 
who is saying what, or in response to whom.

--Ned.

> Cheers!



From fabiosantosart at gmail.com  Sun May 12 13:52:58 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sun, 12 May 2013 18:52:58 +0100
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <518FCF02.9090307@nedbatchelder.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>
	<518FCF02.9090307@nedbatchelder.com>
Message-ID: <CAA=1kxQzek0fSpe4dE-UbRUF3fvkNkLtGUge2p7tAHHNw1z8KQ@mail.gmail.com>

On 12 May 2013 18:23, "Ned Batchelder" <ned at nedbatchelder.com> wrote:
>
> I've never understood why people use that site: the pages end up being
unintelligible cocktail-party noise-scapes with no hope of understanding
who is saying what, or in response to whom.
>
> --Ned.

There's not so much noise there, but indeed the communication gets
confusing after a few paragraphs.
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From tjreedy at udel.edu  Sun May 12 16:26:48 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 12 May 2013 16:26:48 -0400
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <518FCF02.9090307@nedbatchelder.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>
	<518FCF02.9090307@nedbatchelder.com>
Message-ID: <kmottr$27n$2@ger.gmane.org>

On 5/12/2013 1:18 PM, Ned Batchelder wrote:
> On 5/8/2013 10:39 PM, Mark Janssen wrote:
>>> ...The field needs re-invented and re-centered.[...]
>> For anyone who want to be involved.  See the wikiwikiweb -- a tool
>> that every programmer should know and use --  and these pages:
>> ComputerScienceVersionTwo and ObjectOrientedRefactored.
>
> I've never understood why people use that site: the pages end up being
> unintelligible cocktail-party noise-scapes with no hope of understanding
> who is saying what, or in response to whom.

I certainly found it confusing that something responder and OP comments 
were in normal text and italic respectively, and sometimes the opposite, 
and maybe sometimes both in normal types.




From dreamingforward at gmail.com  Mon May 13 00:48:45 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Sun, 12 May 2013 21:48:45 -0700
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <518FCF02.9090307@nedbatchelder.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>
	<518FCF02.9090307@nedbatchelder.com>
Message-ID: <CAMjeLr8qY6fgdwQChcuJSojUrQQciiLO_F4uDvi6LFsA9uvtMw@mail.gmail.com>

On Sun, May 12, 2013 at 10:18 AM, Ned Batchelder <ned at nedbatchelder.com> wrote:
> I've never understood why people use that site: the pages end up being
> unintelligible cocktail-party noise-scapes with no hope of understanding who
> is saying what, or in response to whom.

You're very right.  But that is what has made it sort of a test-bed
for internet collaboration.   The project I'm working on is aimed to
solve that problem and take the Wiki philosophy to its next or even
ultimate level.  By adding a "natural" per-revision voting and
user-ranking it can clear up all the noise and scale to the whole
internet itself.  ....But no one around here seem to think its
possible.
-- 
MarkJ
Tacoma, Washington


From fabiosantosart at gmail.com  Mon May 13 04:29:19 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 13 May 2013 09:29:19 +0100
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAMjeLr8qY6fgdwQChcuJSojUrQQciiLO_F4uDvi6LFsA9uvtMw@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>
	<518FCF02.9090307@nedbatchelder.com>
	<CAMjeLr8qY6fgdwQChcuJSojUrQQciiLO_F4uDvi6LFsA9uvtMw@mail.gmail.com>
Message-ID: <CAA=1kxR7sDU0UxG-5zm8LVLn_XESAAChX5iiuGKgVSHDwBxhvg@mail.gmail.com>

Sounds a lot like reddit threads.
On 13 May 2013 08:17, "Mark Janssen" <dreamingforward at gmail.com> wrote:

> On Sun, May 12, 2013 at 10:18 AM, Ned Batchelder <ned at nedbatchelder.com>
> wrote:
> > I've never understood why people use that site: the pages end up being
> > unintelligible cocktail-party noise-scapes with no hope of understanding
> who
> > is saying what, or in response to whom.
>
> You're very right.  But that is what has made it sort of a test-bed
> for internet collaboration.   The project I'm working on is aimed to
> solve that problem and take the Wiki philosophy to its next or even
> ultimate level.  By adding a "natural" per-revision voting and
> user-ranking it can clear up all the noise and scale to the whole
> internet itself.  ....But no one around here seem to think its
> possible.
> --
> MarkJ
> Tacoma, Washington
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From dreamingforward at gmail.com  Tue May 14 15:11:24 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Tue, 14 May 2013 12:11:24 -0700
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAA=1kxR7sDU0UxG-5zm8LVLn_XESAAChX5iiuGKgVSHDwBxhvg@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>
	<518FCF02.9090307@nedbatchelder.com>
	<CAMjeLr8qY6fgdwQChcuJSojUrQQciiLO_F4uDvi6LFsA9uvtMw@mail.gmail.com>
	<CAA=1kxR7sDU0UxG-5zm8LVLn_XESAAChX5iiuGKgVSHDwBxhvg@mail.gmail.com>
Message-ID: <CAMjeLr-ro4N7Ly87E4fXd+QRMce+SQ2KU4BNnkMZqWkN3_LBog@mail.gmail.com>

> Sounds a lot like reddit threads.

It's similar, but it goes a lot further.  Where every other site
without centralized editors, the thread mess on a simple flat page
doesn't scale after about a 100 interactions.  To sort out the mess,
it takes another dimension.  The project I'm working on uses a 3
dimensional visualization model that can scale and order millions of
nodes.

-- 
MarkJ
Tacoma, Washington


From fabiosantosart at gmail.com  Tue May 14 16:11:29 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 14 May 2013 21:11:29 +0100
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAMjeLr-ro4N7Ly87E4fXd+QRMce+SQ2KU4BNnkMZqWkN3_LBog@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>
	<518FCF02.9090307@nedbatchelder.com>
	<CAMjeLr8qY6fgdwQChcuJSojUrQQciiLO_F4uDvi6LFsA9uvtMw@mail.gmail.com>
	<CAA=1kxR7sDU0UxG-5zm8LVLn_XESAAChX5iiuGKgVSHDwBxhvg@mail.gmail.com>
	<CAMjeLr-ro4N7Ly87E4fXd+QRMce+SQ2KU4BNnkMZqWkN3_LBog@mail.gmail.com>
Message-ID: <CAA=1kxTsJWT6TSLzSv+M2=XOhk4AyAbjx92qD26Ghm__oX5sfg@mail.gmail.com>

Impressive, I'd say.

On Tue, May 14, 2013 at 8:11 PM, Mark Janssen <dreamingforward at gmail.com> wrote:
>> Sounds a lot like reddit threads.
>
> It's similar, but it goes a lot further.  Where every other site
> without centralized editors, the thread mess on a simple flat page
> doesn't scale after about a 100 interactions.  To sort out the mess,
> it takes another dimension.  The project I'm working on uses a 3
> dimensional visualization model that can scale and order millions of
> nodes.
>
> --
> MarkJ
> Tacoma, Washington


--
F?bio Santos


From ian.g.kelly at gmail.com  Tue May 14 15:46:56 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 14 May 2013 13:46:56 -0600
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAMjeLr8qY6fgdwQChcuJSojUrQQciiLO_F4uDvi6LFsA9uvtMw@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CAMjeLr9PxwF6hDheJ+zJPYaX9KYJMUeVxxZk31TTeA+9N0Bz_Q@mail.gmail.com>
	<518FCF02.9090307@nedbatchelder.com>
	<CAMjeLr8qY6fgdwQChcuJSojUrQQciiLO_F4uDvi6LFsA9uvtMw@mail.gmail.com>
Message-ID: <CALwzidm4bXkQhASrP6auZC-sHNctFA2Xp18o3dxXZEdc5OiSUw@mail.gmail.com>

On Sun, May 12, 2013 at 10:48 PM, Mark Janssen
<dreamingforward at gmail.com> wrote:
> You're very right.  But that is what has made it sort of a test-bed
> for internet collaboration.   The project I'm working on is aimed to
> solve that problem and take the Wiki philosophy to its next or even
> ultimate level.  By adding a "natural" per-revision voting and
> user-ranking it can clear up all the noise and scale to the whole
> internet itself.  ....But no one around here seem to think its
> possible.

I may have missed it in the noise, but I don't recall that you ever
proposed such a project "around here".  That said, your brief
description does sound rather like Cloud Cuckoo Land to me.


From ian.g.kelly at gmail.com  Thu May  9 13:33:45 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 9 May 2013 11:33:45 -0600
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
Message-ID: <CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>

On Wed, May 8, 2013 at 8:35 PM, Mark Janssen <dreamingforward at gmail.com> wrote:
> Okay, to anyone who might be listening, I found the core of the problem.

What "problem" are you referring to?  You've been posting on this
topic for going on two months now, and I still have no idea of what
the point of it all is.  I recall something about not being happy with
the OOP paradigm because apparently none of the dozens of existing
languages handle message passing in the particular way that you think
it should work; but if that's all it is, then why don't you just build
a new language that does it the way that you think is right?  If it's
good, spread it around and it will gain traction.  If not, then it
will die the quiet death it deserves.  All this irrelevant nonsense
about Turing machines and lambda calculus that you've injected into
the conversation though just reminds me of the "Einstein was wrong"
cranks.


From rosuav at gmail.com  Thu May  9 13:47:26 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 03:47:26 +1000
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
Message-ID: <CAPTjJmrJV2JpuvzzPDHy=Nh0wrXROp2VkhSHH17bxOsUuWzy_w@mail.gmail.com>

On Fri, May 10, 2013 at 3:33 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> All this irrelevant nonsense
> about Turing machines and lambda calculus that you've injected into
> the conversation though just reminds me of the "Einstein was wrong"
> cranks.

http://xkcd.com/1206/

ChrisA


From darcy at druid.net  Thu May  9 13:51:12 2013
From: darcy at druid.net (D'Arcy J.M. Cain)
Date: Thu, 9 May 2013 13:51:12 -0400
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
Message-ID: <20130509135112.3796431d@imp>

On Thu, 9 May 2013 11:33:45 -0600
Ian Kelly <ian.g.kelly at gmail.com> wrote:
> about Turing machines and lambda calculus that you've injected into
> the conversation though just reminds me of the "Einstein was wrong"
> cranks.

But Einstein *was* wrong.  http://www.xkcd.com/1206/

-- 
D'Arcy J.M. Cain <darcy at druid.net>         |  Democracy is three wolves
http://www.druid.net/darcy/                |  and a sheep voting on
+1 416 788 2246     (DoD#0082)    (eNTP)   |  what's for dinner.
IM: darcy at Vex.Net, VOIP: sip:darcy at Vex.Net


From dreamingforward at gmail.com  Thu May  9 17:51:28 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Thu, 9 May 2013 14:51:28 -0700
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
Message-ID: <CAMjeLr9CTVkH8qxxA1==mbjymyk_gPOG2iGjgeAP9mqC5=FN9w@mail.gmail.com>

On Thu, May 9, 2013 at 10:33 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Wed, May 8, 2013 at 8:35 PM, Mark Janssen <dreamingforward at gmail.com> wrote:
>> Okay, to anyone who might be listening, I found the core of the problem.
>
> What "problem" are you referring to?  You've been posting on this
> topic for going on two months now, and I still have no idea of what
> the point of it all is.

You see Ian, while you and the other millions of coding practitioners
have (mal)adapted to a suboptimal coding environment where "hey
there's a language for everyone"  and terms are thrown around,
misused, this is not how it needs or should be.  Instead of the
thriving Open Source culture on the web we could have, the community
stays fractured.   Languages can reach for an optimal design (within a
constant margin of leeway).   Language "expressivity" can be measured.

--Tron


From ian.g.kelly at gmail.com  Thu May  9 18:30:47 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 9 May 2013 16:30:47 -0600
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAMjeLr9CTVkH8qxxA1==mbjymyk_gPOG2iGjgeAP9mqC5=FN9w@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<CAMjeLr9CTVkH8qxxA1==mbjymyk_gPOG2iGjgeAP9mqC5=FN9w@mail.gmail.com>
Message-ID: <CALwzidkBog8QYFy5V_o9ujPBz1C7sWuEPJFiBteEeLAevtYx2g@mail.gmail.com>

On Thu, May 9, 2013 at 3:51 PM, Mark Janssen <dreamingforward at gmail.com> wrote:
> On Thu, May 9, 2013 at 10:33 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>> On Wed, May 8, 2013 at 8:35 PM, Mark Janssen <dreamingforward at gmail.com> wrote:
>>> Okay, to anyone who might be listening, I found the core of the problem.
>>
>> What "problem" are you referring to?  You've been posting on this
>> topic for going on two months now, and I still have no idea of what
>> the point of it all is.
>
> You see Ian, while you and the other millions of coding practitioners
> have (mal)adapted to a suboptimal coding environment where "hey
> there's a language for everyone"  and terms are thrown around,
> misused, this is not how it needs or should be.  Instead of the
> thriving Open Source culture on the web we could have,

Non sequitur.  Open source software has nothing to do with coding
environment or choice of language or OOP paradigm.  Or Turing machines
or lambda calculus, for that matter.

> the community stays fractured.

The open source community seems pretty healthy to me.  What is the
basis of your claim that it is "fractured"?

> Languages can reach for an optimal design (within a constant margin of leeway).

There is no "optimal design".  The *reason* that "there's a language
for everyone" is because different people think about software in
different ways and find different approaches better suited to them.
Furthermore, some programming styles are naturally more conducive to
accomplishing certain tasks, and worse at others.  Take video game
programming for an example.  If I'm working on the graphics engine for
a game, I would probably want to use a low-level imperative language
for efficiency reasons.  If I'm working on the AI, I will more likely
prefer a functional or declarative language for clarity, flexibility
and static analysis.  In either case, OOP is probably a bad choice.

> Language "expressivity" can be measured.

And the measurements can be endlessly debated.  Expressivity is not
the sole measure of a programming language, though.


From rosuav at gmail.com  Thu May  9 19:05:15 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 09:05:15 +1000
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CALwzidkBog8QYFy5V_o9ujPBz1C7sWuEPJFiBteEeLAevtYx2g@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<CAMjeLr9CTVkH8qxxA1==mbjymyk_gPOG2iGjgeAP9mqC5=FN9w@mail.gmail.com>
	<CALwzidkBog8QYFy5V_o9ujPBz1C7sWuEPJFiBteEeLAevtYx2g@mail.gmail.com>
Message-ID: <CAPTjJmrBBAH3c=koko6NbgA9HZR5uqasPFgBJ2dFnun_8imWhQ@mail.gmail.com>

On Fri, May 10, 2013 at 8:30 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Thu, May 9, 2013 at 3:51 PM, Mark Janssen <dreamingforward at gmail.com> wrote:
>> the community stays fractured.
>
> The open source community seems pretty healthy to me.  What is the
> basis of your claim that it is "fractured"?

The carpentry community is fractured. There are people who use
screwdrivers, and there are people who use hammers! Screws and nails
are such completely different things that we shouldn't try to use the
same language to discuss them.

>> Language "expressivity" can be measured.
>
> And the measurements can be endlessly debated.  Expressivity is not
> the sole measure of a programming language, though.

Every programming language can encode every program. It's fairly
straightforward to prove that a Python interpreter can be written in
Ruby, or a C interpreter in Lua; so there is no program that can be
expressed in one language and not in another (there will be apparent
exceptions, eg web-browser JavaScript cannot call on arbitrary C-level
functionality, but if the entirety of program code were written in C,
then it could all be interpreted by one C interpreter).

Larry Wall of Perl put it this way, in a State of the Onion address:

http://www.perl.com/pub/2007/12/06/soto-11.html
"""... Human languages are Turing complete, as it were.

Human languages therefore differ not so much in what you can say but
in what you must say. In English, you are forced to differentiate
singular from plural. In Japanese, you don't have to distinguish
singular from plural, but you do have to pick a specific level of
politeness, taking into account not only your degree of respect for
the person you're talking to, but also your degree of respect for the
person or thing you're talking about.

So languages differ in what you're forced to say. Obviously, if your
language forces you to say something, you can't be concise in that
particular dimension using your language. Which brings us back to
scripting.

How many ways are there for different scripting languages to be concise?
"""

In C, for example, you are forced to write explicit notation
representing {blocks; of; code;} and explicit characters separating;
statements;. In Python, on the other hand, you have to write out your
indentation. In Java, you state what exceptions you might throw. REXX
mandates that you annotate procedures with their list of exposed names
(effectively, non-local and global variables). So the expressivity of
a language can't be defined in terms of how many programs can be
written in it, but in how concisely they can be written - and that's
something that depends on specific design choices and how they align
with the code you're trying to write.

Compare these two snippets:

#!/bin/sh
pg_dumpall | gzip | ssh user at host 'gzip -d|psql'

#!/usr/bin/env python
words=input("Enter words, blank delimited: ")
lengths=[len(x) for x in words.split(" ")]
print("Average word length: %d"%int(sum(lengths)/len(lengths)))

Could you write each in the other's language? Sure! But it won't be as
concise. (The Python version of the shell script could cheat and just
call on the shell to do the work, but even that would add the
expressive overhead of "os.system".) This is why there are so many
languages: because each is good at something different.

ChrisA


From wuwei23 at gmail.com  Thu May  9 19:58:15 2013
From: wuwei23 at gmail.com (alex23)
Date: Thu, 9 May 2013 16:58:15 -0700 (PDT)
Subject: Message passing syntax for objects | OOPv2
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
Message-ID: <b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>

On 10 May, 07:51, Mark Janssen <dreamingforw... at gmail.com> wrote:
> You see Ian, while you and the other millions of coding practitioners
> have (mal)adapted to a suboptimal coding environment where "hey
> there's a language for everyone" ?and terms are thrown around,
> misused, this is not how it needs or should be.

Please cite your industry experience so we know this is a pragmatic
exercise for you and not a display of public onanism.

> Instead of the
> thriving Open Source culture on the web we could have, the community
> stays fractured.

What fractures communities is telling "millions of [maladapted]
practitioners" that they're wrong, and that your unsubstantiated
intuition somehow trumps their billions of hours of combined
experience.

> Languages can reach for an optimal design (within a
> constant margin of leeway). ? Language "expressivity" can be measured.

I'm sure that's great. I, however, have a major project going live in
a few weeks and would rather just get something done.


From rosuav at gmail.com  Thu May  9 23:07:55 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 13:07:55 +1000
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
Message-ID: <CAPTjJmoXjkro6KFw7KOTuqeLjrDaQJWBrnKss2anu3VftW9UQw@mail.gmail.com>

On Fri, May 10, 2013 at 9:58 AM, alex23 <wuwei23 at gmail.com> wrote:
> On 10 May, 07:51, Mark Janssen <dreamingforw... at gmail.com> wrote:
>> Languages can reach for an optimal design (within a
>> constant margin of leeway).   Language "expressivity" can be measured.
>
> I'm sure that's great. I, however, have a major project going live in
> a few weeks and would rather just get something done.

Hmm, not really a fair argument there. A well-designed language lets
you "just get something done" far more efficiently than a
poorly-designed one. Being confident that similar objects behave
correspondingly when invoked the same way lets you write your code
without fiddling with minutiae, for instance. ("Hmm, I'll just switch
that from being a tuple to being a list, so I can modify this one
element." - code that indexes or iterates won't be affected.)

Now, whether or not it's worth _debating_ the expressiveness of a
language... well, that's another point entirely. But for your major
project, I think you'll do better working in Python than in machine
code.

ChrisA


From dreamingforward at gmail.com  Thu May  9 23:08:28 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Thu, 9 May 2013 20:08:28 -0700
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
Message-ID: <CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>

On Thu, May 9, 2013 at 4:58 PM, alex23 <wuwei23 at gmail.com> wrote:
> On 10 May, 07:51, Mark Janssen <dreamingforw... at gmail.com> wrote:
>> You see Ian, while you and the other millions of coding practitioners
>> have (mal)adapted to a suboptimal coding environment where "hey
>> there's a language for everyone"  and terms are thrown around,
>> misused, this is not how it needs or should be.
>
> Please cite your industry experience so we know this is a pragmatic
> exercise for you and not a display of public onanism.

"Industry experience...."

Do you know all the world's [industrial] leaders are endorsing an
impossible path of endless, exponential growth on a finite planet?

Is that who you answer to?

--m


From rosuav at gmail.com  Fri May 10 00:33:52 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 14:33:52 +1000
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>
Message-ID: <CAPTjJmpPf1wPbR0Y6QJzgKfa-vk9PkraMWQPNdn-ah55a=mcKQ@mail.gmail.com>

On Fri, May 10, 2013 at 1:08 PM, Mark Janssen <dreamingforward at gmail.com> wrote:
> On Thu, May 9, 2013 at 4:58 PM, alex23 <wuwei23 at gmail.com> wrote:
>> On 10 May, 07:51, Mark Janssen <dreamingforw... at gmail.com> wrote:
>>> You see Ian, while you and the other millions of coding practitioners
>>> have (mal)adapted to a suboptimal coding environment where "hey
>>> there's a language for everyone"  and terms are thrown around,
>>> misused, this is not how it needs or should be.
>>
>> Please cite your industry experience so we know this is a pragmatic
>> exercise for you and not a display of public onanism.
>
> "Industry experience...."
>
> Do you know all the world's [industrial] leaders are endorsing an
> impossible path of endless, exponential growth on a finite planet?
>
> Is that who you answer to?

I don't answer to them. I also believe in a path of endless
exponential growth. Challenge: Create more information than can be
stored in one teaspoon of matter. Go ahead. Try!

The first hard disk I ever worked with stored 20MB in the space of a
5.25" slot (plus its associated ISA controller card). Later on we got
3.5" form factor drives, and I remember installing this *gigantic*
FOUR GIGABYTE drive into our disk server. Wow! We'll NEVER use all
that space! (Well, okay. Even then we knew that space consumption kept
going up. But we did figure on that 4GB lasting us a good while, which
it did.) Today, I can pop into Budget PC or MSY (or you folks in the
US could check out newegg) and pick up a terabyte of storage in the
same amount of physical space, or you can go 2.5" form factor and take
up roughly a fifth of the physical space and still get half a terabyte
fairly cheaply. So our exponential growth is being supported by
exponential increases in data per cubic meter. Between that and the
vast size of this planet, I don't think we really need to worry too
much about finite limits to IT growth.

ChrisA


From rosuav at gmail.com  Sat May 11 18:41:00 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 12 May 2013 08:41:00 +1000
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <h27to8159aes54akptn4spgkba8oh8u76r@invalid.netcom.com>
References: <CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>
	<CAPTjJmpPf1wPbR0Y6QJzgKfa-vk9PkraMWQPNdn-ah55a=mcKQ@mail.gmail.com>
	<h27to8159aes54akptn4spgkba8oh8u76r@invalid.netcom.com>
Message-ID: <CAPTjJmoBYf3qmyfO+dmNLR8P=+tVDkv_LFV=QQ=4R4wHBU+YuA@mail.gmail.com>

On Sun, May 12, 2013 at 5:32 AM, Dennis Lee Bieber
<wlfraed at ix.netcom.com> wrote:
> On Fri, 10 May 2013 14:33:52 +1000, Chris Angelico <rosuav at gmail.com>
> declaimed the following in gmane.comp.python.general:
>
>>
>> I don't answer to them. I also believe in a path of endless
>> exponential growth. Challenge: Create more information than can be
>> stored in one teaspoon of matter. Go ahead. Try!
>>
>         The coordinates of each particle storing the information in that
> teaspoon of matter.

Which is probably more data than any of us will keyboard in a
lifetime. Hence my point.

ChrisA


From greg.ewing at canterbury.ac.nz  Sat May 11 21:02:09 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sun, 12 May 2013 13:02:09 +1200
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <mailman.1570.1368312070.3114.python-list@python.org>
References: <CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>	<mailman.1505.1368136296.3114.python-list@python.org>	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>	<CAPTjJmpPf1wPbR0Y6QJzgKfa-vk9PkraMWQPNdn-ah55a=mcKQ@mail.gmail.com>	<h27to8159aes54akptn4spgkba8oh8u76r@invalid.netcom.com>
	<mailman.1570.1368312070.3114.python-list@python.org>
Message-ID: <av880jFb874U1@mid.individual.net>

Chris Angelico wrote:
> On Sun, May 12, 2013 at 5:32 AM, Dennis Lee Bieber
> <wlfraed at ix.netcom.com> wrote:

>>        The coordinates of each particle storing the information in that
>>teaspoon of matter.
> 
> Which is probably more data than any of us will keyboard in a
> lifetime. Hence my point.

My 1TB hard disk *already* contains more information than
I could keyboard in my lifetime.

The fact that it all got there is due to two things: (1)
I didn't have to enter it all myself, and (2) most of it
was auto-generated from other information, using compilers
and other such tools.

Our disk capacities are increasing exponentially, but
so is the rate at which we have the ability to create
information. I wouldn't be surprised if, at some point
before the human race becomes extinct, we build
computers whose operating system requires more than
a teaspoonful of atoms to store. Especially if
Microsoft still exists by then. :-)

-- 
Greg


From rosuav at gmail.com  Sat May 11 21:19:11 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 12 May 2013 11:19:11 +1000
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <av880jFb874U1@mid.individual.net>
References: <CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>
	<CAPTjJmpPf1wPbR0Y6QJzgKfa-vk9PkraMWQPNdn-ah55a=mcKQ@mail.gmail.com>
	<h27to8159aes54akptn4spgkba8oh8u76r@invalid.netcom.com>
	<mailman.1570.1368312070.3114.python-list@python.org>
	<av880jFb874U1@mid.individual.net>
Message-ID: <CAPTjJmpLFCrsVCoRts8-+_84ZEJb7xjjEB1umK_udijzqwoTtg@mail.gmail.com>

On Sun, May 12, 2013 at 11:02 AM, Gregory Ewing
<greg.ewing at canterbury.ac.nz> wrote:
> Chris Angelico wrote:
>>
>> On Sun, May 12, 2013 at 5:32 AM, Dennis Lee Bieber
>> <wlfraed at ix.netcom.com> wrote:
>
>
>>>        The coordinates of each particle storing the information in that
>>> teaspoon of matter.
>>
>>
>> Which is probably more data than any of us will keyboard in a
>> lifetime. Hence my point.
>
>
> My 1TB hard disk *already* contains more information than
> I could keyboard in my lifetime.
>
> The fact that it all got there is due to two things: (1)
> I didn't have to enter it all myself, and (2) most of it
> was auto-generated from other information, using compilers
> and other such tools.

I would like to differentiate between information and data, here.
Point 1 is correct, but point 2 is not; auto-generated data is not
more information, and basic data compression can improve that. (Simple
form of compression there: `rm *.o` - you've lost nothing.)

> Our disk capacities are increasing exponentially, but
> so is the rate at which we have the ability to create
> information. I wouldn't be surprised if, at some point
> before the human race becomes extinct, we build
> computers whose operating system requires more than
> a teaspoonful of atoms to store. Especially if
> Microsoft still exists by then. :-)

That's possible. But that would be data bloat, not true information.
It's certainly possible to conceive more data than can be stored.
Microsoft, as you cite, are experts at this :)

ChrisA


From greg.ewing at canterbury.ac.nz  Sat May 11 20:50:38 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sun, 12 May 2013 12:50:38 +1200
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <mailman.1564.1368301206.3114.python-list@python.org>
References: <CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>	<mailman.1505.1368136296.3114.python-list@python.org>	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>	<CAPTjJmpPf1wPbR0Y6QJzgKfa-vk9PkraMWQPNdn-ah55a=mcKQ@mail.gmail.com>
	<mailman.1564.1368301206.3114.python-list@python.org>
Message-ID: <av87b0Fb43uU1@mid.individual.net>

Dennis Lee Bieber wrote:
>>I also believe in a path of endless
>>exponential growth. Challenge: Create more information than can be
>>stored in one teaspoon of matter. Go ahead. Try!

If that's your argument, then you don't really believe
in *endless* exponential growth. You only believe in
"exponential growth for long enough that I won't be
around to suffer the consequences when it runs out".

-- 
Greg


From rosuav at gmail.com  Sat May 11 21:10:36 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 12 May 2013 11:10:36 +1000
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <av87b0Fb43uU1@mid.individual.net>
References: <CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>
	<CAPTjJmpPf1wPbR0Y6QJzgKfa-vk9PkraMWQPNdn-ah55a=mcKQ@mail.gmail.com>
	<mailman.1564.1368301206.3114.python-list@python.org>
	<av87b0Fb43uU1@mid.individual.net>
Message-ID: <CAPTjJmqGAUSioxwFYb8W7oz523kYabNMkEOuK4fpv-wm_Kc80g@mail.gmail.com>

On Sun, May 12, 2013 at 10:50 AM, Gregory Ewing
<greg.ewing at canterbury.ac.nz> wrote:
> Dennis Lee Bieber wrote:
>>>
>>> I also believe in a path of endless
>>> exponential growth. Challenge: Create more information than can be
>>> stored in one teaspoon of matter. Go ahead. Try!
>
>
> If that's your argument, then you don't really believe
> in *endless* exponential growth. You only believe in
> "exponential growth for long enough that I won't be
> around to suffer the consequences when it runs out".

Technically, according to the laws of thermodynamics, there cannot be
any actually endless growth, yes. (Anything beyond that is the realm
of religion, not science.) But in that case, the term "endless" is
like "infinity" - a concept only. Like the Infinite Monkey Protocol
Suite description in RFC 2795, there will be many numbers that come up
that are plenty huge but fall pitifully short of infinity (Graham's
Number, for instance, is pretty small in those terms).

So long as storage capacities keep on increasing, we can keep
increasing the world's information at the same rate. So long as the
number of computers connected to the internet increases, we can keep
increasing the internet's information at the same rate. Put both
together - and neither shows any sign of ceasing any time soon - we
can continue with the corresponding growth. How long before that runs
out? A *looooong* time. We're not talking here of the Year 2000, a
couple of decades after the software was written. We're not talking
about the 2038 issues, roughly half a century after the software was
written. We are talking timeframes that make the Y10K problem look
like a serious lack of foresight.

ChrisA


From roy at panix.com  Fri May 10 00:55:29 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 10 May 2013 00:55:29 -0400
Subject: Message passing syntax for objects | OOPv2
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>
	<mailman.1523.1368160434.3114.python-list@python.org>
Message-ID: <roy-F13DF9.00552910052013@news.panix.com>

In article <mailman.1523.1368160434.3114.python-list at python.org>,
 Chris Angelico <rosuav at gmail.com> wrote:

> The first hard disk I ever worked with stored 20MB in the space of a
> 5.25" slot (plus its associated ISA controller card).

Heh.  The first hard disk I ever worked with stored 2.4 MB in 6U of rack 
space (plus 4 Unibus cards worth of controller).  That's not actually 
the first hard disk I ever used.  Just the first one I ever got to touch 
with my own hands.

Did I mention that the air filters had to be changed a few times a year?
  
Uphill both ways, in the snow, while beating off the dinosaurs with 
sticks.


From rosuav at gmail.com  Fri May 10 03:37:30 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 17:37:30 +1000
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <roy-F13DF9.00552910052013@news.panix.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>
	<mailman.1523.1368160434.3114.python-list@python.org>
	<roy-F13DF9.00552910052013@news.panix.com>
Message-ID: <CAPTjJmpCviZRfB5v39hdZt+JxqxZinti5Sqp3gFW=UgHdj3msw@mail.gmail.com>

On Fri, May 10, 2013 at 2:55 PM, Roy Smith <roy at panix.com> wrote:
> In article <mailman.1523.1368160434.3114.python-list at python.org>,
>  Chris Angelico <rosuav at gmail.com> wrote:
>
>> The first hard disk I ever worked with stored 20MB in the space of a
>> 5.25" slot (plus its associated ISA controller card).
>
> Heh.  The first hard disk I ever worked with stored 2.4 MB in 6U of rack
> space (plus 4 Unibus cards worth of controller).  That's not actually
> the first hard disk I ever used.  Just the first one I ever got to touch
> with my own hands.
>
> Did I mention that the air filters had to be changed a few times a year?
>
> Uphill both ways, in the snow, while beating off the dinosaurs with
> sticks.

Yeah, I'm pretty young. First computer I ever broke (the same one that
had the aforementioned 20MB drive) addressed a whole megabyte of
memory, 640KB of which was OK (we're left wondering whether anyone
would notice if ROM developed a fault), and I got to play around with
64KB of it in DEBUG.EXE. And yeah, I wrote code straight in DEBUG and
saved it and crashed the system. (Tip: If you want to write a device
driver, make sure you start with your dad happy with you.) Was good
fun. I heartily recommend the exercise, but... uhh... do consider
setting up a virtual machine first :)

ChrisA


From wrw at mac.com  Fri May 10 07:49:11 2013
From: wrw at mac.com (William Ray Wing)
Date: Fri, 10 May 2013 07:49:11 -0400
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <roy-F13DF9.00552910052013@news.panix.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>
	<mailman.1523.1368160434.3114.python-list@python.org>
	<roy-F13DF9.00552910052013@news.panix.com>
Message-ID: <C70CEE75-707C-44C6-8FB2-BF41381EBA03@mac.com>

On May 10, 2013, at 12:55 AM, Roy Smith <roy at panix.com> wrote:

> In article <mailman.1523.1368160434.3114.python-list at python.org>,
> Chris Angelico <rosuav at gmail.com> wrote:
> 
>> The first hard disk I ever worked with stored 20MB in the space of a
>> 5.25" slot (plus its associated ISA controller card).
> 
> Heh.  The first hard disk I ever worked with stored 2.4 MB in 6U of rack 
> space (plus 4 Unibus cards worth of controller).  That's not actually 
> the first hard disk I ever used.  Just the first one I ever got to touch 
> with my own hands.
> 

Sounds suspiciously like an RK05.  We used a lot of those on DEC PDP-8e's.  I can remember how startled I was when I first saw a DEC engineer pull the top off one and then, with it open, spin it up.  The platter inside was warped (a ceiling light reflected off the platter wiggled and then blurred) but the head mechanism actually just followed it up and down!!!

Bill

> Did I mention that the air filters had to be changed a few times a year?
> 
> Uphill both ways, in the snow, while beating off the dinosaurs with 
> sticks.
> -- 
> http://mail.python.org/mailman/listinfo/python-list



From roy at panix.com  Fri May 10 08:58:58 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 10 May 2013 08:58:58 -0400
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <C70CEE75-707C-44C6-8FB2-BF41381EBA03@mac.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
	<CAMjeLr-FMA6sAkd1_fZvZZ9Vaws4P=f__mdzcDNRRADYfN5Q=g@mail.gmail.com>
	<mailman.1523.1368160434.3114.python-list@python.org>
	<roy-F13DF9.00552910052013@news.panix.com>
	<C70CEE75-707C-44C6-8FB2-BF41381EBA03@mac.com>
Message-ID: <3140EE72-3CE2-446F-B77B-066F7460BF25@panix.com>


On May 10, 2013, at 7:49 AM, William Ray Wing wrote:

> On May 10, 2013, at 12:55 AM, Roy Smith <roy at panix.com> wrote:
> 
>> In article <mailman.1523.1368160434.3114.python-list at python.org>,
>> Chris Angelico <rosuav at gmail.com> wrote:
>> 
>>> The first hard disk I ever worked with stored 20MB in the space of a
>>> 5.25" slot (plus its associated ISA controller card).
>> 
>> Heh.  The first hard disk I ever worked with stored 2.4 MB in 6U of rack 
>> space (plus 4 Unibus cards worth of controller).  That's not actually 
>> the first hard disk I ever used.  Just the first one I ever got to touch 
>> with my own hands.
>> 
> 
> Sounds suspiciously like an RK05.

Yup.


--
Roy Smith
roy at panix.com





From wuwei23 at gmail.com  Sat May 11 18:23:17 2013
From: wuwei23 at gmail.com (alex23)
Date: Sat, 11 May 2013 15:23:17 -0700 (PDT)
Subject: Message passing syntax for objects | OOPv2
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<CALwzidn442aiADJwYSzQfAZsHf4RK=sdgt1C7dJHxsHeqiZzPA@mail.gmail.com>
	<mailman.1505.1368136296.3114.python-list@python.org>
	<b864cbc6-746a-4bb0-a5d0-548a84186ec1@ua8g2000pbb.googlegroups.com>
	<mailman.1517.1368155279.3114.python-list@python.org>
Message-ID: <965b6137-9a4f-4bd5-930b-8c242305dbd9@fq2g2000pbb.googlegroups.com>

On 10 May, 13:07, Chris Angelico <ros... at gmail.com> wrote:
> Now, whether or not it's worth _debating_ the expressiveness of a
> language... well, that's another point entirely. But for your major
> project, I think you'll do better working in Python than in machine
> code.

I wasn't disagreeing with the concept of linguistic expressiveness, my
ire was over the "I'm RIGHT and EVERYONE else is WRONG so STOP WHAT
YOU'RE DOING so I can REBUILD COMPUTER SCIENCE" aspect of these posts.
Thought without experience or experiment is about as useful to my work
requirements as bowel gas.



From wuwei23 at gmail.com  Thu May  9 19:53:56 2013
From: wuwei23 at gmail.com (alex23)
Date: Thu, 9 May 2013 16:53:56 -0700 (PDT)
Subject: Message passing syntax for objects | OOPv2
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<CAMjeLr9OSD4B-2NHNra=Acyj1h0g8VLOVwjFFm5c35TX+Vu5SA@mail.gmail.com>
	<mailman.1498.1368121272.3114.python-list@python.org>
Message-ID: <f6982288-1d79-416f-9511-610113aa9314@h9g2000pbr.googlegroups.com>

On 10 May, 03:33, Ian Kelly <ian.g.ke... at gmail.com> wrote:
> You've been posting on this
> topic for going on two months now, and I still have no idea of what
> the point of it all is.

As Charlie Brooker put it: "almost every monologue consists of nothing
but the words PLEASE AUTHENTICATE MY EXISTENCE, repeated over and over
again, in disguise".


From rustompmody at gmail.com  Wed May  8 23:26:49 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 8 May 2013 20:26:49 -0700 (PDT)
Subject: Message passing syntax for objects | OOPv2
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<mailman.1475.1368066966.3114.python-list@python.org>
Message-ID: <4558a365-4c27-4656-9cc9-9efbdec31e6a@pl9g2000pbb.googlegroups.com>

On May 9, 7:35?am, Mark Janssen <dreamingforw... at gmail.com> wrote:
> On Fri, Apr 12, 2013 at 11:28 PM, Mark Janssen
>
> <dreamingforw... at gmail.com> wrote:
> >> Mark, this proposal is out of place on a Python list, because it proposes an
> >> object methodology radically different from any that is implemented in
> >> Python now, or is even remotely likely to be implemented in Python in the
> >> future.
>
> > Wow, you guys are a bunch of ninnies. ?I'm going to find some
> > theoretical folks....
>
> Okay, to anyone who might be listening, I found the core of the problem.
>
> This issue is/was much deeper than OOP (which would be roughly a 20
> year refactoring) -- that was my mistake. ?The issue goes right to the
> core to models of computation and the historical factions within
> theoretical CS itself (a 50+ year refactoring).
>
> The field needs re-invented and re-centered. ?Mark my words. ?There
> has been a half-century of confusion between two entirely separate
> domains and they've been using the same lexicon. ?Long story short:
> the lambda calculus folks have to split from the Turing machine folks.
> ?These models of computation should not use the same language. ?Their
> computation models are too radically different. ?Lisp will remain a
> pinnacle of the lambda calculus, but should be remanded to philosophy.
> ?The logic of the binary/boolean arithmetic is simply not compatible,
> but forms the basis of any sensible computer science here in the West.
>
> Here pronouncith the.... whatever
>
> --
> MarkJ
> Tacoma, Washington

"Lisp will remain the pinnacle of lambda calculus" ???  : Surreal
feeling of falling into a 25-year time-warp

Read this http://www.cs.kent.ac.uk/people/staff/dat/miranda/wadler87.pdf

Just for historical context:
When this was written in the 80s:
- The FP languages of the time -- KRC, SASL, Miranda, Orwell -- were
elegant and academic
- Lisp was quasi-industrial-strength but as Wadler argues above, was
not doing good service to functional programming


From dreamingforward at gmail.com  Wed May  8 23:53:42 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Wed, 8 May 2013 20:53:42 -0700
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <4558a365-4c27-4656-9cc9-9efbdec31e6a@pl9g2000pbb.googlegroups.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<mailman.1475.1368066966.3114.python-list@python.org>
	<4558a365-4c27-4656-9cc9-9efbdec31e6a@pl9g2000pbb.googlegroups.com>
Message-ID: <CAMjeLr_xALGG5UHbzBidQUp2GmPNqtfAVKf=i0D4PF_h=JqDVw@mail.gmail.com>

> "Lisp will remain the pinnacle of lambda calculus" ???  : Surreal
> feeling of falling into a 25-year time-warp
>
> Read this http://www.cs.kent.ac.uk/people/staff/dat/miranda/wadler87.pdf
>
> Just for historical context:
> When this was written in the 80s:
> - The FP languages of the time -- KRC, SASL, Miranda, Orwell -- were
> elegant and academic
> - Lisp was quasi-industrial-strength but as Wadler argues above, was
> not doing good service to functional programming

Fascinating.
-- 
MarkJ
Tacoma, Washington


From steve+comp.lang.python at pearwood.info  Thu May  9 01:39:37 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 05:39:37 GMT
Subject: Message passing syntax for objects | OOPv2
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<mailman.1475.1368066966.3114.python-list@python.org>
Message-ID: <518b3699$0$11120$c3e8da3@news.astraweb.com>

On Wed, 08 May 2013 19:35:58 -0700, Mark Janssen wrote:

> Long story short: the lambda
> calculus folks have to split from the Turing machine folks.
>  These models of computation should not use the same language.  Their
> computation models are too radically different.  

Their computation models are exactly equivalent.

This is like saying that Cartesian coordinates and polar coordinates are 
so radically different that they cannot possibly both describe the same 
space.


-- 
Steven


From rustompmody at gmail.com  Thu May  9 07:56:44 2013
From: rustompmody at gmail.com (rusi)
Date: Thu, 9 May 2013 04:56:44 -0700 (PDT)
Subject: Alternate computational models can be harmonious (was Message passing
	syntax for objects | OOPv2)
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<mailman.1475.1368066966.3114.python-list@python.org>
	<518b3699$0$11120$c3e8da3@news.astraweb.com>
Message-ID: <294f7dda-3ead-47b5-a191-29556213d859@g5g2000pbp.googlegroups.com>

On May 9, 10:39?am, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
> On Wed, 08 May 2013 19:35:58 -0700, Mark Janssen wrote:
> > Long story short: the lambda
> > calculus folks have to split from the Turing machine folks.
> > ?These models of computation should not use the same language. ?Their
> > computation models are too radically different.
>
> Their computation models are exactly equivalent.
>
> This is like saying that Cartesian coordinates and polar coordinates are
> so radically different that they cannot possibly both describe the same
> space.

Spot on Steven -- thanks.

And further we do know that from a pragmatic POV the two can be quite
different.
For example cartesian are easier for add/subtract, whereas polar are
easier for multiply/divide.
And so on occasion the best way of doing an operation is to -- if
necessary -- convert to the more appropriate format.

I feel that the case of alternate computation models is analogous --
for some purposes one model works well and sometimes another.

Python embeds the functional model almost as natively as it does the
imperative/OO model.  This is an aspect of python that is powerful but
can also make it hard for some people. In short, python's multi-
paradigm possibilities could do with some good publicity.

My own attempts at bringing functional thinking to classical
imperative languages and Python in particular, will be up at:
https://moocfellowship.org/submissions/the-dance-of-functional-programming-languaging-with-haskell-and-python

It is also an attempt at bringing the lightness and freedom of Python
to the Haskell community and answer divisive judgements of
computational models/paradigms such as the OP's.

More details at http://blog.languager.org/2013/05/dance-of-functional-programming.html


From dreamingforward at gmail.com  Thu May  9 17:41:26 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Thu, 9 May 2013 14:41:26 -0700
Subject: Message passing syntax for objects | OOPv2
In-Reply-To: <518b3699$0$11120$c3e8da3@news.astraweb.com>
References: <CAMjeLr_eJf1Aboz=2+oti4TOV=oejUYVo7K4zks+Ck4CSHaqpg@mail.gmail.com>
	<5167F327.3030803@nedbatchelder.com>
	<CAMjeLr8+pr12+0mN0SOrtg9ZTkNq=PiqxWyqB8CxpJ0BT=sxJA@mail.gmail.com>
	<mailman.1475.1368066966.3114.python-list@python.org>
	<518b3699$0$11120$c3e8da3@news.astraweb.com>
Message-ID: <CAMjeLr_xOFOT1jbfWFdf1WqVMFvUgOBEZ_a98NWq+QhH6y-kFg@mail.gmail.com>

>>  These models of computation should not use the same language.  Their
>> computation models are too radically different.
>
> Their computation models are exactly equivalent.

No they are not.  While one can find levels of indirection to
translate between one and the other, that doesn't mean they're
equivalent.  It's like saying that because I can make an equivalence
between the complex plane and the real, that they should be treated as
equivalent.  But they shouldn't -- else you run into a domain error.

-- 
MarkJ
Tacoma, Washington


From cjw at ncf.ca  Fri May  3 19:49:27 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Fri, 03 May 2013 19:49:27 -0400
Subject: [ANNC] pynguin-0.14 python turtle graphics application
In-Reply-To: <mailman.583.1365898236.3114.python-list@python.org>
References: <mailman.580.1365895556.3114.python-list@python.org>
	<mailman.583.1365898236.3114.python-list@python.org>
Message-ID: <51844D07.9000803@ncf.ca>

On 13/04/2013 8:10 PM, Miki Tebeka wrote:
>> Pynguin is a python-based turtle graphics application.
> I wonder why Pynguin does not get more traction in the teaching sector. Looks ideal for teaching kids.

Mili,

I suggest that it's because Pynguin is not yet fully operational.

I don't know where to report problems.

The problems I had were installing for Python 3.3 and 2.7, using win32

In the latter case, it seem as though the code is tied with 3.3.

On the face of it, the package appear to have potential.

Colin W.




From cjw at ncf.ca  Fri May  3 19:49:27 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Fri, 03 May 2013 19:49:27 -0400
Subject: [ANNC] pynguin-0.14 python turtle graphics application
In-Reply-To: <mailman.583.1365898236.3114.python-list@python.org>
References: <mailman.580.1365895556.3114.python-list@python.org>
	<mailman.583.1365898236.3114.python-list@python.org>
Message-ID: <51844D07.9000803@ncf.ca>

On 13/04/2013 8:10 PM, Miki Tebeka wrote:
>> Pynguin is a python-based turtle graphics application.
> I wonder why Pynguin does not get more traction in the teaching sector. Looks ideal for teaching kids.

Mili,

I suggest that it's because Pynguin is not yet fully operational.

I don't know where to report problems.

The problems I had were installing for Python 3.3 and 2.7, using win32

In the latter case, it seem as though the code is tied with 3.3.

On the face of it, the package appear to have potential.

Colin W.




From jurgis.pralgauskis at gmail.com  Fri May  3 12:01:17 2013
From: jurgis.pralgauskis at gmail.com (Jurgis Pralgauskis)
Date: Fri, 3 May 2013 19:01:17 +0300
Subject: [Edu-sig] [ANNC] pynguin-0.14 python turtle graphics application
In-Reply-To: <BLU168-W68BF2A6FD7F1D9A0E9F53DB1C20@phx.gbl>
References: <BLU168-W68BF2A6FD7F1D9A0E9F53DB1C20@phx.gbl>
Message-ID: <CANDo6EyCdchu-0+CEAf-yUfBYA71U9p7RFSRC+qVCUoor=UJxQ@mail.gmail.com>

Hi,

do you plan to make step/debug functionality
as it is made in RurPLE?

I generally like  RurPLE-NG
http://dev.lshift.net/paul/rurple/

I improoved it fore easier learning
http://grokbase.com/t/python/edu-sig/129r2hkchm/rurple-ng-is-nice#20121113xy5wryeowevmgumpyo6o3t6jka

but moving around just rows and columns is a bit boring --
Would it be hard to somehow merge code tracking with Pynguin?




On Sun, Apr 14, 2013 at 2:24 AM, Lee Harr <missive at hotmail.com> wrote:

> Pynguin is a python-based turtle graphics application.
>     It combines an editor, interactive interpreter, and
>     graphics display area.
>
> It is meant to be an easy environment for introducing
>     some programming concepts to beginning programmers.
>
>
> http://pynguin.googlecode.com/
>
>
> This release adds several user-requested features, including
>     circular arcs, SVG export, and undo.
>
>
> Pynguin is tested with Python 3.2.3 and PyQt 4.9.3 and
>     will use Pygments syntax highlighting if available.
>
> Pynguin is released under GPLv3.
>
>
> Changes in pynguin-0.14:
>     Important fixes
>
>     Other fixes
>
>     Pynguin API
>         - Added font() to change font for use with write()
>         - Added move parameter for write()
>         - Added align and valign parameters for write()
>         - Added arc() for circular arcs
>
>     Canvas
>         - Added SVG Export
>
>     UI
>         - Added ability to use translations
>         - Added (basic) undo capability (ctrl-z)
>
>     Integrated Editor
>         - Added shortcut (ctrl-w) for removing doc pages
>         - Stop asking for confirmation to remove empty doc page
>         - Stop autosave from modifying empty doc page
>
>     Integrated Console
>
>     Examples
>         - Added arc examples
> _______________________________________________
> Edu-sig mailing list
> Edu-sig at python.org
> http://mail.python.org/mailman/listinfo/edu-sig
>



-- 
Jurgis Pralgauskis
tel: 8-616 77613;
Don't worry, be happy and make things better ;)
http://galvosukykla.lt
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From cjw at ncf.ca  Fri May  3 19:53:28 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Fri, 03 May 2013 19:53:28 -0400
Subject: [Edu-sig] [ANNC] pynguin-0.14 python turtle graphics application
In-Reply-To: <mailman.1271.1367596878.3114.python-list@python.org>
References: <BLU168-W68BF2A6FD7F1D9A0E9F53DB1C20@phx.gbl>
	<mailman.1271.1367596878.3114.python-list@python.org>
Message-ID: <51844DF8.8010206@ncf.ca>

On 03/05/2013 12:01 PM, Jurgis Pralgauskis wrote:
> Hi,
>
> do you plan to make step/debug functionality
> as it is made in RurPLE?
>
> I generally like  RurPLE-NG
> http://dev.lshift.net/paul/rurple/
>
> I improoved it fore easier learning
> http://grokbase.com/t/python/edu-sig/129r2hkchm/rurple-ng-is-nice#20121113xy5wryeowevmgumpyo6o3t6jka
>
> but moving around just rows and columns is a bit boring --
> Would it be hard to somehow merge code tracking with Pynguin?
>
>
I tried to run it using PySCripter, but I didn't get far enough to check 
it out

Colin W.

[snip]



From cjw at ncf.ca  Fri May  3 19:53:28 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Fri, 03 May 2013 19:53:28 -0400
Subject: [Edu-sig] [ANNC] pynguin-0.14 python turtle graphics application
In-Reply-To: <mailman.1271.1367596878.3114.python-list@python.org>
References: <BLU168-W68BF2A6FD7F1D9A0E9F53DB1C20@phx.gbl>
	<mailman.1271.1367596878.3114.python-list@python.org>
Message-ID: <51844DF8.8010206@ncf.ca>

On 03/05/2013 12:01 PM, Jurgis Pralgauskis wrote:
> Hi,
>
> do you plan to make step/debug functionality
> as it is made in RurPLE?
>
> I generally like  RurPLE-NG
> http://dev.lshift.net/paul/rurple/
>
> I improoved it fore easier learning
> http://grokbase.com/t/python/edu-sig/129r2hkchm/rurple-ng-is-nice#20121113xy5wryeowevmgumpyo6o3t6jka
>
> but moving around just rows and columns is a bit boring --
> Would it be hard to somehow merge code tracking with Pynguin?
>
>
I tried to run it using PySCripter, but I didn't get far enough to check 
it out

Colin W.

[snip]



From missive at hotmail.com  Sat May  4 01:20:28 2013
From: missive at hotmail.com (Lee Harr)
Date: Sat, 4 May 2013 09:50:28 +0430
Subject: [ANNC] pynguin-0.14 python turtle graphics application
Message-ID: <BLU168-W13500ED77C6EB3FC0ECC65DB1BF0@phx.gbl>

>>> Pynguin is a python-based turtle graphics application.
>>> http://pynguin.googlecode.com/

>> I wonder why Pynguin does not get more traction in the teaching sector.
>> Looks ideal for teaching kids.

> I suggest that it's because Pynguin is not yet fully operational.
> I don't know where to report problems.

Go to the home page and click on "Issues"

You can also email me directly. I appreciate any feedback.


> The problems I had were installing for Python 3.3 and 2.7, using win32
> it seem as though the code is tied with 3.3

>>> ?Pynguin is tested with Python 3.2.3 and PyQt 4.9.3

For anyone struggling with installing on Windows, please see:
https://code.google.com/p/pynguin/wiki/InstallingPynguinOnWindows

I realize it is not simple to install on Windows, especially for the
target audience, beginners. I have an open issue "Difficult to start
the program on Windows" which could use more attention.

The simplest way forward is to use Portable Python 2 and use
the 0.12 version of Pynguin (the last one to support Python 2)

It is also possible to run the latest version (0.14) on Portable
Python 3 but it takes some experience to get PyQt installed
in the right place. 		 	   		  

From dreamingforward at gmail.com  Wed May  1 16:32:39 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Wed, 1 May 2013 13:32:39 -0700
Subject: The type/object distinction and possible synthesis of OOP and
	imperative programming languages
In-Reply-To: <5170A77F.7040002@nedbatchelder.com>
References: <mailman.618.1365997692.3114.python-list@python.org>
	<516bd241$0$29872$c3e8da3$5496439d@news.astraweb.com>
	<516C3C44.6010706@rece.vub.ac.be>
	<mailman.647.1366060446.3114.python-list@python.org>
	<kkhtqc$15t$1@dont-email.me>
	<CAPTjJmpqXYZ=p6xo9+KOBbG56qRSPtdyWaKOHM3AV4GhrLiXPA@mail.gmail.com>
	<CAMjeLr9fjsrZqwb=x22Ft74nxFVM8D+vgyjH2BrWB_wkV3V1gQ@mail.gmail.com>
	<mailman.779.1366303050.3114.python-list@python.org>
	<51709740$0$29977$c3e8da3$5496439d@news.astraweb.com>
	<roy-C68066.21082218042013@news.panix.com>
	<CAMjeLr-B-RMR1uMsjNc_XxVePYbG5o7UhKBVgxxxTdVJZ-K1xQ@mail.gmail.com>
	<5170A77F.7040002@nedbatchelder.com>
Message-ID: <CAMjeLr-LzyObLbioP7socOY40ijTmemuAnBR7AQ5YRhsKfya3A@mail.gmail.com>

>> Here's a simple rule to resolve the ambiguity.   Whoever publishes
>> first, gets to claim origin of a word and its usage, kind of like a
>> BDFL.  The rest can adapt around that, make up their own word, or be
>> corrected as the community requires.
>
> You seem to want to squeeze all of computer science and programming into a
> tidy hierarchy.  It won't work, it's not tidy. I strongly suggest you read
> more about computer science before forming more opinions.  You have a lot to
> learn ahead of you.

Done:  see the wikiwikiweb:  http://c2.com/cgi/wiki?ComputerScienceVersionTwo
-- 
MarkJ
Tacoma, Washington


From wuwei23 at gmail.com  Wed May  1 21:13:33 2013
From: wuwei23 at gmail.com (alex23)
Date: Wed, 1 May 2013 18:13:33 -0700 (PDT)
Subject: The type/object distinction and possible synthesis of OOP and
	imperative programming languages
References: <mailman.618.1365997692.3114.python-list@python.org>
	<516bd241$0$29872$c3e8da3$5496439d@news.astraweb.com>
	<516C3C44.6010706@rece.vub.ac.be>
	<mailman.647.1366060446.3114.python-list@python.org>
	<kkhtqc$15t$1@dont-email.me>
	<CAPTjJmpqXYZ=p6xo9+KOBbG56qRSPtdyWaKOHM3AV4GhrLiXPA@mail.gmail.com>
	<CAMjeLr9fjsrZqwb=x22Ft74nxFVM8D+vgyjH2BrWB_wkV3V1gQ@mail.gmail.com>
	<mailman.779.1366303050.3114.python-list@python.org>
	<51709740$0$29977$c3e8da3$5496439d@news.astraweb.com>
	<roy-C68066.21082218042013@news.panix.com>
	<CAMjeLr-B-RMR1uMsjNc_XxVePYbG5o7UhKBVgxxxTdVJZ-K1xQ@mail.gmail.com>
	<5170A77F.7040002@nedbatchelder.com>
	<mailman.1222.1367440361.3114.python-list@python.org>
Message-ID: <9fb4fe47-368f-4587-a30b-7b7336e913a4@mq5g2000pbb.googlegroups.com>

On May 2, 6:32?am, Mark Janssen <dreamingforw... at gmail.com> wrote:
> > You seem to want to squeeze all of computer science and programming into a
> > tidy hierarchy. ?It won't work, it's not tidy. I strongly suggest you read
> > more about computer science before forming more opinions. ?You have a lot to
> > learn ahead of you.
>
> Done: ?see the wikiwikiweb: ?http://c2.com/cgi/wiki?ComputerScienceVersionTwo

"There are two camps:
Us, who are right and good.
Them, who are wrong and evil.
Us should be supported, whilst Them should be condemned."

Wow. Just....wow. Because the world really needs a manichean model of
computation.


From dieter at handshake.de  Wed May  1 04:33:16 2013
From: dieter at handshake.de (dieter)
Date: Wed, 01 May 2013 10:33:16 +0200
Subject: Finding referents with Gdb
References: <CANm61jfK-W+rhZz+68va_P7R-j1ddq0-RhLawigC3kc4md=Yxw@mail.gmail.com>
Message-ID: <87hain14mr.fsf@handshake.de>

Dave Butler <daveb at tanagerproductions.com> writes:

> with gdb, can you find referents of an object given an object id?

Usually no.

"gdb" is a C level debugger. If debugging information is available
(and the type of an object know), "gdb" can show you the fields
of an object. If you know the correct type, you can cast an object
to this type and get the field information. Thus, "gdb" gives you
a possibility to examine the objects, a given object refers to.
However, in general, there is no data structure (in a C program) that
provides access to the objects that refer to a given object.
In such cases, "gdb" cannot help you to find those objects.





From stefan_ml at behnel.de  Wed May  1 04:46:51 2013
From: stefan_ml at behnel.de (Stefan Behnel)
Date: Wed, 01 May 2013 10:46:51 +0200
Subject: Finding referents with Gdb
In-Reply-To: <CANm61jfK-W+rhZz+68va_P7R-j1ddq0-RhLawigC3kc4md=Yxw@mail.gmail.com>
References: <CANm61jfK-W+rhZz+68va_P7R-j1ddq0-RhLawigC3kc4md=Yxw@mail.gmail.com>
Message-ID: <klqkpm$5bd$1@ger.gmane.org>

Dave Butler, 23.04.2013 16:52:
> with gdb, can you find referents of an object given an object id?

Have you looked at the gc module? And, could you explain why you want to
work with the object's ID instead of the object reference itself?

Stefan




From skip at pobox.com  Wed May  1 06:53:22 2013
From: skip at pobox.com (Skip Montanaro)
Date: Wed, 1 May 2013 05:53:22 -0500
Subject: Finding referents with Gdb
In-Reply-To: <CANm61jfK-W+rhZz+68va_P7R-j1ddq0-RhLawigC3kc4md=Yxw@mail.gmail.com>
References: <CANm61jfK-W+rhZz+68va_P7R-j1ddq0-RhLawigC3kc4md=Yxw@mail.gmail.com>
Message-ID: <CANc-5Uw5tQp7KVa_n+Z6NLairS71e9c-D3LFuwA70FDYhuuE6Q@mail.gmail.com>

On Tue, Apr 23, 2013 at 9:52 AM, Dave Butler
<daveb at tanagerproductions.com> wrote:
> with gdb, can you find referents of an object given an object id?

Look at the C code for gc.get_referents and set things up to call it from GDB.

Skip


From mikefromgreenburghnewyork at gmail.com  Sat May  4 23:37:17 2013
From: mikefromgreenburghnewyork at gmail.com (Michael Marshall)
Date: Sat, 4 May 2013 20:37:17 -0700 (PDT)
Subject: Libroffice PMT equivalent in python
In-Reply-To: <mailman.1054.1366886971.3114.python-list@python.org>
References: <mailman.1054.1366886971.3114.python-list@python.org>
Message-ID: <ff8fbc4b-6864-471e-a8c1-cf6919fc3749@googlegroups.com>

On Thursday, April 25, 2013 6:46:01 AM UTC-4, ??????? wrote:
> Hi,
> 
> 
> 
> Are there equivalent in any Python libraries that could match function
> 
> like PMT in libreoffice?
> 
> 
> 
> Refer: https://help.libreoffice.org/Calc/Financial_Functions_Part_Two#PMT
> 
> 
> 
> --
> 
> 
> 
> Amachu

The PMT function in spreadsheet programs (Excel, OpenOffice Calc, LibreOffice Calc, Symphony Calc, Gnumeric) and in pocket financial calculators (Texas Instruments BA II plus, HP 10B II, Casio Fc 100, 200) will provide an answer for the initial (periodic) payment. Whereas depending on the value of number of periods NPER there may be 5 different payments as explained below

0) the periodic payment
This is the payment that is in constant amount and is paid or collected over the life of investment assuming the number of periods are in whole and do not have a fractional part

If the number of periods have a fractional part such as 10.5 years of 119.25 months then besides the initial periodic payment, there may be 4 different last payments to choose from

1) Balloon payment
When the NPER has a fraction, then the last payment may be made or collected at the last full time period for example if NPER is 10.5 then the balloon payment is made at the end of year 10 where you pay the periodic payment plus the remaining principal and the interest due

2) Actual last payment
When the NPER has a fraction, you may opt to pay or collect the last payment at the actual time period. For example if NPER is 10.5 then you will make or collect the last payment at the end of 10 years and 6 months. This last payment will be the principal remaining after making 10 payments and will also include the interest on remaining principal

3) Drop payment
When the NPER has a fraction, you may opt to pay or collect the last payment at the end of the next full year. For example if NPER is 10.5 then you will make or collect the last payment at the end of 11 years. This last payment will be the principal remainining plus the interest on it

4) Partial period payment
But then if the NPER has a fraction, you may still opt to pay or collect the payment at the actual time period but the amount you pay is the fraction of time period times the remaining principal. Thus if the NPER is 10.5 you make the last payment at the end of 10 years and 6 months in amount of 0.5 * remaining_principal

Now the present value of the periodic payments plus the last payments from case 1, 2, 3 comes out to be the same as the loan amount. But this is not the case if we use payment from case number 4, in this instance the lender collects a few extra bucks from the borrower.

Excel financial functions were copied from those found in Lotus 123 and the financial functions in OpenOffice Calc, LibreOffice Calc, Symphony Calc are copies from Excel.

This Excel PMT function http://tadxl.com/excel_pmt_function.html offers the options of finding any of the 5 different payments as explained in the previous paragraphs. And it even goes further and finds all periodic payments when payments are growing, shrinking, increasing or decreasing. In this last case there may be as many different payments as there are number of periods. All this is part of tadXL add-in http://tadxl.com/


From mikefromgreenburghnewyork at gmail.com  Sat May  4 23:55:07 2013
From: mikefromgreenburghnewyork at gmail.com (Michael Marshall)
Date: Sat, 4 May 2013 20:55:07 -0700 (PDT)
Subject: Libroffice PMT equivalent in python
In-Reply-To: <ff8fbc4b-6864-471e-a8c1-cf6919fc3749@googlegroups.com>
References: <mailman.1054.1366886971.3114.python-list@python.org>
	<ff8fbc4b-6864-471e-a8c1-cf6919fc3749@googlegroups.com>
Message-ID: <b6a851cf-12dd-46f4-b79e-bd5ea8f800e0@googlegroups.com>

On Saturday, May 4, 2013 11:37:17 PM UTC-4, Michael Marshall wrote:
> On Thursday, April 25, 2013 6:46:01 AM UTC-4, ??????? wrote:

> If the number of periods have a fractional part such as 10.5 years of 119.25 months then besides the initial periodic payment, there may be 4 different last payments to choose from
> 


EDIT

There was a typo in my text

I meant to write

If the number of periods have a fractional part such as 10.5 years OR 119.25 months


From mikefromgreenburghnewyork at gmail.com  Sun May  5 00:05:16 2013
From: mikefromgreenburghnewyork at gmail.com (Michael Marshall)
Date: Sat, 4 May 2013 21:05:16 -0700 (PDT)
Subject: Libroffice PMT equivalent in python
In-Reply-To: <ff8fbc4b-6864-471e-a8c1-cf6919fc3749@googlegroups.com>
References: <mailman.1054.1366886971.3114.python-list@python.org>
	<ff8fbc4b-6864-471e-a8c1-cf6919fc3749@googlegroups.com>
Message-ID: <a95612b1-8f4c-49d7-bc33-a66b5c923a0c@googlegroups.com>

On Saturday, May 4, 2013 11:37:17 PM UTC-4, Michael Marshall wrote:

> 4) Partial period payment
> 
> But then if the NPER has a fraction, you may still opt to pay or collect the payment at the actual time period but the amount you pay is the fraction of time period times the remaining principal. Thus if the NPER is 10.5 you make the last payment at the end of 10 years and 6 months in amount of 0.5 * remaining_principal
> 

EDIT 

Meant to write

But then if the NPER has a fraction, you may still opt to pay or collect the payment at the actual time period but the amount you pay is the fraction of time period times the periodic payment. Thus if the NPER is 10.5 you make the last payment at the end of 10 years and 6 months in amount of 0.5 * periodic_payment


From maitreymishra23 at gmail.com  Thu May  2 10:13:48 2013
From: maitreymishra23 at gmail.com (Maitrey Mishra)
Date: Thu, 2 May 2013 16:13:48 +0200
Subject: Efficient way of looging in python
In-Reply-To: <229947553.5215691.1366982379397.JavaMail.root@sequans.com>
References: <CAO=YJ3d3qUAnnfA5vRJORJ3VGSzaEAskAR7Tgi_JZKtsefBkKA@mail.gmail.com>
	<229947553.5215691.1366982379397.JavaMail.root@sequans.com>
Message-ID: <CAO=YJ3eTO2mPfiUHrkeDREcJ96ouDzrx-khbHzEbxTD0OPbweg@mail.gmail.com>

I wrote some tests for logging module. I use python 2.6 and use the example
as in cookbook
file : Test_Task.py
from threading import Thread
import Logging.logQueueHandler as logq

class TestTask(threading.Thread):
def __init__(self):
pass

def run(self):
t = Thread(target=logq.log, args=("ERROR", "Hi"))
t.start()
q = Thread(target=logq.log, args=("ERROR", "Hello"))
q.start()
p = Thread(target=logq.log, args=("ERROR", "How are you?"))
p.start()
l = Thread(target=logq.log, args=("ERROR", "I am fine, Thank You!"))
l.start()
call_test.py
from Test_Task import TestTask
import unittest

task = TestTask()
task.run()
However, In the log messages I see a number of messages missing.
With the tests, my aim is to see how logging works with multiple threads.


On Fri, Apr 26, 2013 at 3:19 PM, Jean-Michel Pichavant <
jeanmichel at sequans.com> wrote:

> Yep that's the one I used.
>
> ------------------------------
>
> Ah,
> http://plumberjack.blogspot.de/2010/09/using-logging-with-multiprocessing.html
> I use this now, it seems to work!
> Thanks!
>
>
> On Fri, Apr 26, 2013 at 2:16 PM, Maitrey Mishra <maitreymishra23 at gmail.com
> > wrote:
>
>> Hi All,
>> Thanks for the inputs.
>> I use python2.6. It seems to be easier with python3.2 and QueueHandler
>> class.
>> I pasted the class in my code however I still get the
>> error: AttributeError: 'module' object has no attribute 'QueueHandler'
>> What changes did you do for adapting to python2.5?
>>
>> Thanks!
>> Br,
>> Maitrey
>>
>>
>>
>> On Thu, Apr 25, 2013 at 4:32 PM, Jean-Michel Pichavant <
>> jeanmichel at sequans.com> wrote:
>>
>>> ----- Original Message -----
>>> > Hi,
>>> >
>>> > I need an efficient way of logging using python.
>>> > My problem statemnt:
>>> > 1. I have multiple processes using the same logging file.
>>> > I need solutions to the following:
>>> > a) If multiple processes are trying to write to the same file, I need
>>> > to prevent that. Otherwise, the logging messages will be puzzling to
>>> > the user as he would see logging messages from one module than may
>>> > be some other following it.
>>> >
>>> > Please let me know if there is an efficient way to do it.
>>> >
>>> > Thanks!
>>> >
>>> > Br,
>>> > Maitrey
>>> > --
>>> > http://mail.python.org/mailman/listinfo/python-list
>>>
>>> Everything you need should be explained here
>>>
>>> http://docs.python.org/release/3.2/howto/logging-cookbook.html#logging-to-a-single-file-from-multiple-processes
>>>
>>> Most of the concepts are applicable to any version of python I've done
>>> it with python 2.5. I used some Vinay's code posted on the net to implement
>>> a logging server, all my processes are logging to that server which is
>>> responsible for writing the file.
>>>
>>> JM
>>>
>>>
>>> -- IMPORTANT NOTICE:
>>>
>>> The contents of this email and any attachments are confidential and may
>>> also be privileged. If you are not the intended recipient, please notify
>>> the sender immediately and do not disclose the contents to any other
>>> person, use it for any purpose, or store or copy the information in any
>>> medium. Thank you.
>>>
>>
>>
>
>
>
> -- IMPORTANT NOTICE:
>
> The contents of this email and any attachments are confidential and may
> also be privileged. If you are not the intended recipient, please notify
> the sender immediately and do not disclose the contents to any other
> person, use it for any purpose, or store or copy the information in any
> medium. Thank you.
>
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From maitreymishra23 at gmail.com  Thu May  2 10:33:56 2013
From: maitreymishra23 at gmail.com (Maitrey Mishra)
Date: Thu, 2 May 2013 16:33:56 +0200
Subject: Efficient way of looging in python
In-Reply-To: <CAO=YJ3eTO2mPfiUHrkeDREcJ96ouDzrx-khbHzEbxTD0OPbweg@mail.gmail.com>
References: <CAO=YJ3d3qUAnnfA5vRJORJ3VGSzaEAskAR7Tgi_JZKtsefBkKA@mail.gmail.com>
	<229947553.5215691.1366982379397.JavaMail.root@sequans.com>
	<CAO=YJ3eTO2mPfiUHrkeDREcJ96ouDzrx-khbHzEbxTD0OPbweg@mail.gmail.com>
Message-ID: <CAO=YJ3fB8f-vcSJSONSSyfsnVOwFgeeDcymrs762kiGKopdgaQ@mail.gmail.com>

Sometimes, I notice the below errors:
 python call_Test.py
Traceback (most recent call last):
  File "call_Test.py", line 1, in <module>
    from Test_Task import TestTask
  File
"/cygdrive/d/smoketest/targetflasher/flasher_server/Source/Test_Task.py",
line 5, in <module>
    import Logging.logQueueHandler as logq
  File
"/cygdrive/d/smoketest/targetflasher/flasher_server/Source/Logging/logQueueHandler.py",
line 72, in <module>
    queue = multiprocessing.Queue(-1)
  File "/usr/lib/python2.6/multiprocessing/__init__.py", line 213, in Queue
    return Queue(maxsize)
  File "/usr/lib/python2.6/multiprocessing/queues.py", line 37, in __init__
    self._rlock = Lock()
  File "/usr/lib/python2.6/multiprocessing/synchronize.py", line 117, in
__init__
    SemLock.__init__(self, SEMAPHORE, 1, 1)
  File "/usr/lib/python2.6/multiprocessing/synchronize.py", line 49, in
__init__
    sl = self._semlock = _multiprocessing.SemLock(kind, value, maxvalue)
OSError: [Errno 17] File exists



On Thu, May 2, 2013 at 4:13 PM, Maitrey Mishra <maitreymishra23 at gmail.com>wrote:

> I wrote some tests for logging module. I use python 2.6 and use the
> example as in cookbook
> file : Test_Task.py
> from threading import Thread
> import Logging.logQueueHandler as logq
>
> class TestTask(threading.Thread):
> def __init__(self):
> pass
>
> def run(self):
> t = Thread(target=logq.log, args=("ERROR", "Hi"))
> t.start()
> q = Thread(target=logq.log, args=("ERROR", "Hello"))
> q.start()
> p = Thread(target=logq.log, args=("ERROR", "How are you?"))
> p.start()
> l = Thread(target=logq.log, args=("ERROR", "I am fine, Thank You!"))
> l.start()
> call_test.py
> from Test_Task import TestTask
> import unittest
>
> task = TestTask()
> task.run()
> However, In the log messages I see a number of messages missing.
> With the tests, my aim is to see how logging works with multiple threads.
>
>
> On Fri, Apr 26, 2013 at 3:19 PM, Jean-Michel Pichavant <
> jeanmichel at sequans.com> wrote:
>
>> Yep that's the one I used.
>>
>> ------------------------------
>>
>> Ah,
>> http://plumberjack.blogspot.de/2010/09/using-logging-with-multiprocessing.html
>> I use this now, it seems to work!
>> Thanks!
>>
>>
>> On Fri, Apr 26, 2013 at 2:16 PM, Maitrey Mishra <
>> maitreymishra23 at gmail.com> wrote:
>>
>>> Hi All,
>>> Thanks for the inputs.
>>> I use python2.6. It seems to be easier with python3.2 and QueueHandler
>>> class.
>>> I pasted the class in my code however I still get the
>>> error: AttributeError: 'module' object has no attribute 'QueueHandler'
>>> What changes did you do for adapting to python2.5?
>>>
>>> Thanks!
>>> Br,
>>> Maitrey
>>>
>>>
>>>
>>> On Thu, Apr 25, 2013 at 4:32 PM, Jean-Michel Pichavant <
>>> jeanmichel at sequans.com> wrote:
>>>
>>>> ----- Original Message -----
>>>> > Hi,
>>>> >
>>>> > I need an efficient way of logging using python.
>>>> > My problem statemnt:
>>>> > 1. I have multiple processes using the same logging file.
>>>> > I need solutions to the following:
>>>> > a) If multiple processes are trying to write to the same file, I need
>>>> > to prevent that. Otherwise, the logging messages will be puzzling to
>>>> > the user as he would see logging messages from one module than may
>>>> > be some other following it.
>>>> >
>>>> > Please let me know if there is an efficient way to do it.
>>>> >
>>>> > Thanks!
>>>> >
>>>> > Br,
>>>> > Maitrey
>>>> > --
>>>> > http://mail.python.org/mailman/listinfo/python-list
>>>>
>>>> Everything you need should be explained here
>>>>
>>>> http://docs.python.org/release/3.2/howto/logging-cookbook.html#logging-to-a-single-file-from-multiple-processes
>>>>
>>>> Most of the concepts are applicable to any version of python I've done
>>>> it with python 2.5. I used some Vinay's code posted on the net to implement
>>>> a logging server, all my processes are logging to that server which is
>>>> responsible for writing the file.
>>>>
>>>> JM
>>>>
>>>>
>>>> -- IMPORTANT NOTICE:
>>>>
>>>> The contents of this email and any attachments are confidential and may
>>>> also be privileged. If you are not the intended recipient, please notify
>>>> the sender immediately and do not disclose the contents to any other
>>>> person, use it for any purpose, or store or copy the information in any
>>>> medium. Thank you.
>>>>
>>>
>>>
>>
>>
>>
>> -- IMPORTANT NOTICE:
>>
>> The contents of this email and any attachments are confidential and may
>> also be privileged. If you are not the intended recipient, please notify
>> the sender immediately and do not disclose the contents to any other
>> person, use it for any purpose, or store or copy the information in any
>> medium. Thank you.
>>
>
>
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From fabiosantosart at gmail.com  Wed May  1 17:00:40 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Wed, 1 May 2013 22:00:40 +0100
Subject: "python.exe has stopped working" when os.execl() runs on Windows 7
In-Reply-To: <0d9d14dc-877b-4b68-aefe-834b530dee2c@googlegroups.com>
References: <2e11de8b-f7e1-407f-a2fd-a08d5ce55d0b@googlegroups.com>
	<mailman.1131.1367110561.3114.python-list@python.org>
	<b53733c1-7d3f-47dd-bc6d-7f33fa91aa78@googlegroups.com>
	<mailman.1132.1367114541.3114.python-list@python.org>
	<9ac24332-ead8-4889-815a-a12052f43742@googlegroups.com>
	<klikch$m3$1@ger.gmane.org>
	<CAA=1kxTrTFESz30QVRcjgXd3NRvMriYz640j=hR7qjp_QrBs=A@mail.gmail.com>
	<mailman.1136.1367136310.3114.python-list@python.org>
	<0d9d14dc-877b-4b68-aefe-834b530dee2c@googlegroups.com>
Message-ID: <CAA=1kxQoSJNE3BgJEbOM54g0zQjcRMgzCPkXDZKC86knnBPHyg@mail.gmail.com>

Reproduced in Windows 7 Ultimate:

>>> import os
>>> os.execl('ping.exe', '')

At this point the REPL freezes, and windows prompts me to close Python
since it stopped responding.


--
F?bio Santos


From neilc at norwich.edu  Thu May  2 08:50:09 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 2 May 2013 12:50:09 GMT
Subject: "python.exe has stopped working" when os.execl() runs on Windows 7
References: <2e11de8b-f7e1-407f-a2fd-a08d5ce55d0b@googlegroups.com>
	<mailman.1131.1367110561.3114.python-list@python.org>
	<b53733c1-7d3f-47dd-bc6d-7f33fa91aa78@googlegroups.com>
	<mailman.1132.1367114541.3114.python-list@python.org>
	<9ac24332-ead8-4889-815a-a12052f43742@googlegroups.com>
	<klikch$m3$1@ger.gmane.org>
	<CAA=1kxTrTFESz30QVRcjgXd3NRvMriYz640j=hR7qjp_QrBs=A@mail.gmail.com>
	<mailman.1136.1367136310.3114.python-list@python.org>
	<0d9d14dc-877b-4b68-aefe-834b530dee2c@googlegroups.com>
	<mailman.1223.1367442043.3114.python-list@python.org>
Message-ID: <auf5o1Fovg8U1@mid.individual.net>

On 2013-05-01, F?bio Santos <fabiosantosart at gmail.com> wrote:
> Reproduced in Windows 7 Ultimate:
>
>>>> import os
>>>> os.execl('ping.exe', '')
>
> At this point the REPL freezes, and windows prompts me to close Python
> since it stopped responding.

To repeat others and the documentation:

  In either case, the arguments to the child process should start
  with the name of the command being run, but this is not
  enforced.

The argument list must contain the executable as its first
argument. Python indeed crashes if I don't include the first
argument as directed.

In any case, on Windows I would normally need to do something
like this instead:

os.execlp('cmd.exe', 'cmd.exe', '/K', 'ping.exe')

-- 
Neil Cerutti


From ned at nedbatchelder.com  Wed May  1 18:01:39 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Wed, 01 May 2013 18:01:39 -0400
Subject: How do I encode and decode this data to write to a file?
In-Reply-To: <Zridnb6s37SKGhzMnZ2dnUVZ8u6dnZ2d@giganews.com>
References: <27s15a-943.ln1@chris.zbmc.eu>
	<Zridnb6s37SKGhzMnZ2dnUVZ8u6dnZ2d@giganews.com>
Message-ID: <518190C3.8080708@nedbatchelder.com>


On 5/1/2013 5:20 PM, Tony the Tiger wrote:
> On Mon, 29 Apr 2013 10:47:46 +0100, cl wrote:
>
>>          raw = os.path.join(directory, self.getNameNoExtension()) +
>>          ".html"
>>          file = open(raw, "w")
>>          file.write("".join(html).encode('utf-8'))
>>          file.close()
> This works for me:
>
> Python 2.7.3 (default, Aug  1 2012, 05:16:07)
> [GCC 4.6.3] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>> html='<html><head><title>Blah</title><body>????</body></html>'
>>>> f=open('test.html', 'w')
>>>> f.write(''.join(html.decode('utf-8').encode('utf-8')))
>>>> f.close()
> Perhaps there are better ways to do it.

Your .write() line is exactly equivalent to:

     f.write(html)

Because: if X is a UTF-8 bytestring, then:

     X.decode('utf-8').encode('utf-8') == X

And if X is a bytestring, then:

     ''.join(X) == X

--Ned.

>
>   /Grrr



From ned at nedbatchelder.com  Wed May  1 19:36:19 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Wed, 01 May 2013 19:36:19 -0400
Subject: How do I encode and decode this data to write to a file?
In-Reply-To: <27s15a-943.ln1@chris.zbmc.eu>
References: <27s15a-943.ln1@chris.zbmc.eu>
Message-ID: <5181A6F3.3050800@nedbatchelder.com>


On 4/29/2013 5:47 AM, cl at isbd.net wrote:
> If I understand correctly the encode() is saying that it can't
> understand the data in the html because there's a character 0xc3 in it.
> I *think* this means that the ? is encoded in UTF-8 already in the
> incoming data stream (should be as my system is wholly UTF-8 as far as I
> know and I created the directory name).
>
> So how do I change the code so I don't get the error?  Do I just
> decode() the data first and then encode() it?
>

BTW, I did a presentation at PyCon 2012 that many people have found 
helpful: Pragmatic Unicode, or, How Do I Stop the Pain: 
http://nedbatchelder.com/text/unipain.html .  It explains the principles 
at work here.

--Ned.


From Robert.Flintham at uhb.nhs.uk  Wed May  1 04:06:41 2013
From: Robert.Flintham at uhb.nhs.uk (Robert Flintham)
Date: Wed, 1 May 2013 09:06:41 +0100
Subject: Drag and drop in Windows
In-Reply-To: <20130430231705.EB0BC44A84B@nhs-pd1e-esg008.ad1.nhs.net>
References: <mailman.1148.1367231567.3114.python-list@python.org>
	<20130430231705.EB0BC44A84B@nhs-pd1e-esg008.ad1.nhs.net>
Message-ID: <20130501080655.CEC2C4486FA@nhs-pd1e-esg102.ad1.nhs.net>

Thanks Kevin, that looks great.  It's having trouble finding TkDND though - is there a certain place in the "Python27" directory that it's most likely to look?  It's currently under Lib/site-packages, but I'm suspicious that Tk/Tkinter has its own library somewhere.

Christian - you were right.  The TkDND DLL looks to be for x64.  Is there a way around this?

All the best,
Rob



-----Original Message-----
From: Python-list [mailto:python-list-bounces+robert.flintham=uhb.nhs.uk at python.org] On Behalf Of Kevin Walzer
Sent: 01 May 2013 00:10
To: python-list at python.org
Subject: Re: Drag and drop in Windows

Official link:

http://tkinterdnd.sourceforge.net

-- 
http://mail.python.org/mailman/listinfo/python-list

DISCLAIMER:
This email and any attachments hereto contains proprietary information, some or all of which may be confidential or legally privileged. It is for the exclusive use of the intended recipient(s) only. If an addressing or transmission error has misdirected this e-mail and you are not the intended recipient(s), please notify the author by replying to this e-mail. If you are not the intended recipient you must not use, disclose, distribute, copy, print, or rely on this e-mail or any attachments, as this may be unlawful.



From auriocus at gmx.de  Wed May  1 04:25:34 2013
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Wed, 01 May 2013 10:25:34 +0200
Subject: Drag and drop in Windows
In-Reply-To: <mailman.1209.1367395612.3114.python-list@python.org>
References: <mailman.1148.1367231567.3114.python-list@python.org>
	<20130430231705.EB0BC44A84B@nhs-pd1e-esg008.ad1.nhs.net>
	<mailman.1209.1367395612.3114.python-list@python.org>
Message-ID: <klqjbi$co4$1@dont-email.me>

Hi Robert,

Am 01.05.13 10:06, schrieb Robert Flintham:
> Thanks Kevin, that looks great.  It's having trouble finding TkDND
> though - is there a certain place in the "Python27" directory that
> it's most likely to look?  It's currently under Lib/site-packages,
> but I'm suspicious that Tk/Tkinter has its own library somewhere.

Does it do a "package require?" In that case, check your auto path

	tk.eval('set auto_path')
Tcl looks for the libs in the folders listed there.

> Christian - you were right.  The TkDND DLL looks to be for x64.  Is
> there a way around this?
>

Just download the right version:

http://sourceforge.net/projects/tkdnd/files/Windows%20Binaries/TkDND%202.6/

I haven't checked the content, but expect the "*ix86.tar.gz" file to be 
32 bit, whereas the "*x86_64.tar.gz" is 64 bit (despite the "win32" in 
the name).

You can extract tar.gz using winzip for example. I think it is a mistake 
to package Windows binaries using tar.gz instead of ZIP.

	Christian


From jimmie.he at gmail.com  Sat May  4 06:26:48 2013
From: jimmie.he at gmail.com (Jimmie He)
Date: Sat, 4 May 2013 03:26:48 -0700 (PDT)
Subject: Can read in the BMP data correctly ,but the size is not right?
In-Reply-To: <mailman.1159.1367258242.3114.python-list@python.org>
References: <aee818ca-e077-4e52-be55-7b8282684ba4@googlegroups.com>
	<mailman.1159.1367258242.3114.python-list@python.org>
Message-ID: <0b3223e6-2414-45a3-9493-3df54ee643d6@googlegroups.com>

Totally right!Thanks again!


From rosuav at gmail.com  Wed May  1 00:37:34 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 1 May 2013 14:37:34 +1000
Subject: in need of some help...
In-Reply-To: <47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
Message-ID: <CAPTjJmqhCgeXX_WH3T-+ugrG2KDGdJG=FNkaMUf5aPFn6DPa5A@mail.gmail.com>

On Wed, May 1, 2013 at 9:20 AM, Alex Norton <ayjayn1101 at gmail.com> wrote:
> the teacher actually cant teach anything, he as the knowledge of Vb but his teaching methods are abysmal and severely lacking, but he said we can use any language we feel more comfortable in. some are using VB others PHP and some in C ++.

Quit the course and go study someplace else... I wouldn't want to be
in any course where people use VB and PHP to build GUIs!

ChrisA


From ayjayn1101 at gmail.com  Wed May  1 06:27:50 2013
From: ayjayn1101 at gmail.com (Alex Norton)
Date: Wed, 1 May 2013 03:27:50 -0700 (PDT)
Subject: in need of some help...
In-Reply-To: <mailman.1206.1367383063.3114.python-list@python.org>
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<mailman.1206.1367383063.3114.python-list@python.org>
Message-ID: <db69c379-f70c-4d70-989b-5dee6933d909@googlegroups.com>

On Wednesday, 1 May 2013 05:37:34 UTC+1, Chris Angelico  wrote:
> On Wed, May 1, 2013 at 9:20 AM, Alex Norton <ayjayn1101 at gmail.com> wrote:
> 
> > the teacher actually cant teach anything, he as the knowledge of Vb but his teaching methods are abysmal and severely lacking, but he said we can use any language we feel more comfortable in. some are using VB others PHP and some in C ++.
> 
> 
> 
> Quit the course and go study someplace else... I wouldn't want to be
> 
> in any course where people use VB and PHP to build GUIs!
> 
> 
> 
> ChrisA

its a college course (Uk college btw) and its the last unit... im just gonna stick with it

python is quite easy ot understand (reading wise) that the teacher can attempt to read it with my comments


From jt at toerring.de  Wed May  1 08:15:28 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 1 May 2013 12:15:28 GMT
Subject: in need of some help...
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
Message-ID: <aucfb0F61jrU1@mid.uni-berlin.de>

Alex Norton <ayjayn1101 at gmail.com> wrote:
> thanks... ill take a look at the Qt event handling

It's rather simple: instead of the program running through a
sequence of steps, the program normally is basically doing
nothing. It just reacts to events that normally come from
the user, i.e. the user clicks on some icon or widget, or
(s)he enters something via the keyboard. You etermine which
of all the possible events to which widget are relevant to
you, write handler functions for them and tell the widget
to call some function when an event happens. The simplest
case is a button: you want to react to it, so you write a
function for what's to be done when it's clicked on and
then tell Qt to call that function once it gets clicked
(there are different events even for a simple push button,
it can be clicked, just pushed, released etc.). And if you
have set up everything for that you tell Qt to start waiting
for events.

So the steps are:

  1. Tell Qt that this is a program using it

     app = QtGui.QApplication( sys.argv )

  2. Create your graphical interface (what you seem to
     have done more or less)

  3. Connect desired events (what's called "signals" in
     Qt lingo) for a certain widget to the function to be
     called with something like

     your_widget.clicked.connect( your_function )

     (replace 'clicked' with e.g. 'pushed' or 'released'
     when interested in a push or release signal instead)

  4. Start the event loop (i.e. have Qt wait for the user
     to do something and call one of your functions if the
     user did something you're interested in) with

     app.exec_( )

     When this returns the game is over.

So you don't wait for keyboard input with input() like in
your original program but instead tell Qt to do the waiting
for you and call the appropriate function you defined when
something interesting happens.

What you probably will have to change about the graphical
interface is that instead of using QLabel widgets for 'Air',
'Earth', 'Fire', 'Water' to use e.g. QPushButtons since
QLabels are rather static objects - they don't receive any
"click" events and it's rather likely some kind of event
like this is what you're going to want to react to. And for
that QPushButtons seem to be the simplest choice to start
with.

So have an 'Air' button (let's call it 'bAir' and then do

   bAir.clicked.connect( air_clicked )

after defining a function air_clicked() in which you deal
with that case. that might be as simple as

def air_clicked( ) :
	# Randomly pick one of 'air', 'fire', 'water' or 'earth'

    z = [ 'air', 'fire', 'water', earth' ][ random.randrange( 4 ) ]

	if z == 'air' :
        print( 'Stalemate' )
    elif z == 'water' :
        print( 'Air removes Water, you win!' )
    ...

Now, when during the game the 'Air' button is clicked this
function will get called.

Of course, it might be nicer to have a "result" label some-
where in the graphical interface which you set to the text
instead of printing it out to the console. And you also will
probably add some "Quit" button to end the game.

                              Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From ayjayn1101 at gmail.com  Wed May  1 19:24:16 2013
From: ayjayn1101 at gmail.com (Alex Norton)
Date: Wed, 1 May 2013 16:24:16 -0700 (PDT)
Subject: in need of some help...
In-Reply-To: <aucfb0F61jrU1@mid.uni-berlin.de>
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
Message-ID: <7f7c31dc-94cf-45d7-8556-a56d09293559@googlegroups.com>

Thank you very much for the specific detail. I have already done the signal for the finish button so that the app closes when clicked


From ayjayn1101 at gmail.com  Fri May 10 04:23:40 2013
From: ayjayn1101 at gmail.com (Alex Norton)
Date: Fri, 10 May 2013 01:23:40 -0700 (PDT)
Subject: in need of some help...
In-Reply-To: <aucfb0F61jrU1@mid.uni-berlin.de>
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
Message-ID: <ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>

On Wednesday, 1 May 2013 13:15:28 UTC+1, Jens Thoms Toerring  wrote:
> Alex Norton <ayjayn1101 at gmail.com> wrote:
> 
> > thanks... ill take a look at the Qt event handling
> 
> 
> 
> It's rather simple: instead of the program running through a
> 
> sequence of steps, the program normally is basically doing
> 
> nothing. It just reacts to events that normally come from
> 
> the user, i.e. the user clicks on some icon or widget, or
> 
> (s)he enters something via the keyboard. You etermine which
> 
> of all the possible events to which widget are relevant to
> 
> you, write handler functions for them and tell the widget
> 
> to call some function when an event happens. The simplest
> 
> case is a button: you want to react to it, so you write a
> 
> function for what's to be done when it's clicked on and
> 
> then tell Qt to call that function once it gets clicked
> 
> (there are different events even for a simple push button,
> 
> it can be clicked, just pushed, released etc.). And if you
> 
> have set up everything for that you tell Qt to start waiting
> 
> for events.
> 
> 
> 
> So the steps are:
> 
> 
> 
>   1. Tell Qt that this is a program using it
> 
> 
> 
>      app = QtGui.QApplication( sys.argv )
> 
> 
> 
>   2. Create your graphical interface (what you seem to
> 
>      have done more or less)
> 
> 
> 
>   3. Connect desired events (what's called "signals" in
> 
>      Qt lingo) for a certain widget to the function to be
> 
>      called with something like
> 
> 
> 
>      your_widget.clicked.connect( your_function )
> 
> 
> 
>      (replace 'clicked' with e.g. 'pushed' or 'released'
> 
>      when interested in a push or release signal instead)
> 
> 
> 
>   4. Start the event loop (i.e. have Qt wait for the user
> 
>      to do something and call one of your functions if the
> 
>      user did something you're interested in) with
> 
> 
> 
>      app.exec_( )
> 
> 
> 
>      When this returns the game is over.
> 
> 
> 
> So you don't wait for keyboard input with input() like in
> 
> your original program but instead tell Qt to do the waiting
> 
> for you and call the appropriate function you defined when
> 
> something interesting happens.
> 
> 
> 
> What you probably will have to change about the graphical
> 
> interface is that instead of using QLabel widgets for 'Air',
> 
> 'Earth', 'Fire', 'Water' to use e.g. QPushButtons since
> 
> QLabels are rather static objects - they don't receive any
> 
> "click" events and it's rather likely some kind of event
> 
> like this is what you're going to want to react to. And for
> 
> that QPushButtons seem to be the simplest choice to start
> 
> with.
> 
> 
> 
> So have an 'Air' button (let's call it 'bAir' and then do
> 
> 
> 
>    bAir.clicked.connect( air_clicked )
> 
> 
> 
> after defining a function air_clicked() in which you deal
> 
> with that case. that might be as simple as
> 
> 
> 
> def air_clicked( ) :
> 
> 	# Randomly pick one of 'air', 'fire', 'water' or 'earth'
> 
> 
> 
>     z = [ 'air', 'fire', 'water', earth' ][ random.randrange( 4 ) ]
> 
> 
> 
> 	if z == 'air' :
> 
>         print( 'Stalemate' )
> 
>     elif z == 'water' :
> 
>         print( 'Air removes Water, you win!' )
> 
>     ...
> 
> 
> 
> Now, when during the game the 'Air' button is clicked this
> 
> function will get called.
> 
> 
> 
> Of course, it might be nicer to have a "result" label some-
> 
> where in the graphical interface which you set to the text
> 
> instead of printing it out to the console. And you also will
> 
> probably add some "Quit" button to end the game.
> 
> 
> 
>                               Regards, Jens
> 
> -- 
> 
>   \   Jens Thoms Toerring  ___      jt at toerring.de
> 
>    \__________________________      http://toerring.de

how would i go about adding print outcomes of all options  to a label ?


From jt at toerring.de  Sat May 11 18:20:13 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 11 May 2013 22:20:13 GMT
Subject: in need of some help...
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>
Message-ID: <av7ugtF8ptkU1@mid.uni-berlin.de>

Alex Norton <ayjayn1101 at gmail.com> wrote:
> On Wednesday, 1 May 2013 13:15:28 UTC+1, Jens Thoms Toerring  wrote:
> > Of course, it might be nicer to have a "result" label some-
> > where in the graphical interface which you set to the text
> > instead of printing it out to the console. And you also will
> > probably add some "Quit" button to end the game.
>
> how would i go about adding print outcomes of all options  to a label ?

If you have a QLabel you can set its text to anything you want
using its setText() method.
                                 Regaeds, Jens

PS: If I may ask you a favor: consider refraining from using Google's
    completely broken interface to newsgroups - your post consists
    of nearly 200 lines of text containing all I wrote, with an empty
    line inserted between each of them, and a single line of text
    you wrote. It's rather annoying to have to sieve through that
    much of unrelated stuff just to find thar one line that's re-
    levant. And this Google groups crap seems to make it nearly
    impossible to do it any other way. If you don't believe me see
    e.g.

      http://wiki.python.org/moin/GoogleGroupsPython

    There are much better alternatives to "Google groups",
    using a real usenet news server and a program that does
    not mess up content of news group postings. They've been
    developed with 30 years of experience with newsgroups.

    If I'd be conspiracy theorist I would conclude that Google
    is up to something bad in trying to make using newsgroups
    nearly impossible by their badly broken stuff (and, to add
    credibility to such a claim, their complete disregard for
    all the criticism they got over the years, actually making
    each version of Google groups even worse), but it's rather
    likely just another case of pure incompetence (or a "why
    should we care" attitude:-(
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From kwpolska at gmail.com  Sun May 12 11:59:54 2013
From: kwpolska at gmail.com (=?UTF-8?B?Q2hyaXMg4oCcS3dwb2xza2HigJ0gV2Fycmljaw==?=)
Date: Sun, 12 May 2013 17:59:54 +0200
Subject: in need of some help...
In-Reply-To: <av7ugtF8ptkU1@mid.uni-berlin.de>
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>
	<av7ugtF8ptkU1@mid.uni-berlin.de>
Message-ID: <CAMw+j7LQr9x4RU=0gJV8VsBL-KzdTYAHy9z94dNyiiAvcgpofw@mail.gmail.com>

(slightly offtopic, sorry.)

On Sun, May 12, 2013 at 12:20 AM, Jens Thoms Toerring <jt at toerring.de> wrote:
> PS: If I may ask you a favor: consider refraining from using Google's
>     completely broken interface to newsgroups - your post consists
>     of nearly 200 lines of text containing all I wrote, with an empty
>     line inserted between each of them, and a single line of text
>     you wrote. It's rather annoying to have to sieve through that
>     much of unrelated stuff just to find thar one line that's re-
>     levant.

Gmail automatically hides long quotes.  This is helpful in situations
like this one.  More mail software should implement that
functionality.  Seriously: once you go Gmail, you never go back.

>             And this Google groups crap seems to make it nearly
>     impossible to do it any other way. If you don't believe me see
>     e.g.
>
>       http://wiki.python.org/moin/GoogleGroupsPython
>
>     There are much better alternatives to "Google groups",
>     using a real usenet news server and a program that does
>     not mess up content of news group postings. They've been
>     developed with 30 years of experience with newsgroups.

Or something even better: a mailing list.
http://mail.python.org/mailman/listinfo/python-list is where you can
find it.  Much friendlier than Usenet, and the software itself is
developed by the FLUFL.

>     If I'd be conspiracy theorist I would conclude that Google
>     is up to something bad in trying to make using newsgroups
>     nearly impossible by their badly broken stuff (and, to add
>     credibility to such a claim, their complete disregard for
>     all the criticism they got over the years, actually making
>     each version of Google groups even worse), but it's rather
>     likely just another case of pure incompetence (or a "why
>     should we care" attitude:-(

They shouldn?t care because Usenet users often yell ?Get off my
lawn!?.  Young people don?t use newsgroups.  They don?t even know what
Usenet is.

--
Kwpolska <http://kwpolska.tk> | GPG KEY: 5EAAEA16
stop html mail                | always bottom-post
http://asciiribbon.org        | http://caliburn.nl/topposting.html


From rosuav at gmail.com  Sun May 12 12:08:58 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 13 May 2013 02:08:58 +1000
Subject: in need of some help...
In-Reply-To: <CAMw+j7LQr9x4RU=0gJV8VsBL-KzdTYAHy9z94dNyiiAvcgpofw@mail.gmail.com>
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>
	<av7ugtF8ptkU1@mid.uni-berlin.de>
	<CAMw+j7LQr9x4RU=0gJV8VsBL-KzdTYAHy9z94dNyiiAvcgpofw@mail.gmail.com>
Message-ID: <CAPTjJmo7ecZZkyov4YVMZSUOpisF6Ljb0971KL0Mz+UL9NiRQQ@mail.gmail.com>

On Mon, May 13, 2013 at 1:59 AM, Chris ?Kwpolska? Warrick
<kwpolska at gmail.com> wrote:
> On Sun, May 12, 2013 at 12:20 AM, Jens Thoms Toerring <jt at toerring.de> wrote:
>> PS: If I may ask you a favor: consider refraining from using Google's
>>     completely broken interface to newsgroups - your post consists
>>     of nearly 200 lines of text containing all I wrote, with an empty
>>     line inserted between each of them, and a single line of text
>>     you wrote. It's rather annoying to have to sieve through that
>>     much of unrelated stuff just to find thar one line that's re-
>>     levant.
>
> Gmail automatically hides long quotes.  This is helpful in situations
> like this one.  More mail software should implement that
> functionality.  Seriously: once you go Gmail, you never go back.

I use Gmail, but the automated hiding of long quotes is *disrupted* by
the double-spacing. So it's no less important to avoid breaking
protocol.

ChrisA


From ayjayn1101 at gmail.com  Sun May 12 15:34:24 2013
From: ayjayn1101 at gmail.com (Alex Norton)
Date: Sun, 12 May 2013 12:34:24 -0700 (PDT)
Subject: in need of some help...
In-Reply-To: <av7ugtF8ptkU1@mid.uni-berlin.de>
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>
	<av7ugtF8ptkU1@mid.uni-berlin.de>
Message-ID: <e8537d4c-d408-486a-b887-a7ad5d82e249@googlegroups.com>

On Saturday, 11 May 2013 23:20:13 UTC+1, Jens Thoms Toerring  wrote:
> Alex Norton <ayjayn1101 at gmail.com> wrote:
> 
> > On Wednesday, 1 May 2013 13:15:28 UTC+1, Jens Thoms Toerring  wrote:
> 
> > > Of course, it might be nicer to have a "result" label some-
> 
> > > where in the graphical interface which you set to the text
> 
> > > instead of printing it out to the console. And you also will
> 
> > > probably add some "Quit" button to end the game.
> 
> >
> 
> > how would i go about adding print outcomes of all options  to a label ?
> 
> 
> 
> If you have a QLabel you can set its text to anything you want
> 
> using its setText() method.
> 
>                                  Regaeds, Jens
> 
> 
> 
> PS: If I may ask you a favor: consider refraining from using Google's
> 
>     completely broken interface to newsgroups - your post consists
> 
>     of nearly 200 lines of text containing all I wrote, with an empty
> 
>     line inserted between each of them, and a single line of text
> 
>     you wrote. It's rather annoying to have to sieve through that
> 
>     much of unrelated stuff just to find thar one line that's re-
> 
>     levant. And this Google groups crap seems to make it nearly
> 
>     impossible to do it any other way. If you don't believe me see
> 
>     e.g.
> 
> 
> 
>       http://wiki.python.org/moin/GoogleGroupsPython
> 
> 
> 
>     There are much better alternatives to "Google groups",
> 
>     using a real usenet news server and a program that does
> 
>     not mess up content of news group postings. They've been
> 
>     developed with 30 years of experience with newsgroups.
> 
> 
> 
>     If I'd be conspiracy theorist I would conclude that Google
> 
>     is up to something bad in trying to make using newsgroups
> 
>     nearly impossible by their badly broken stuff (and, to add
> 
>     credibility to such a claim, their complete disregard for
> 
>     all the criticism they got over the years, actually making
> 
>     each version of Google groups even worse), but it's rather
> 
>     likely just another case of pure incompetence (or a "why
> 
>     should we care" attitude:-(
> 
> -- 
> 
>   \   Jens Thoms Toerring  ___      jt at toerring.de
> 
>    \__________________________      http://toerring.de

i have taken your advice and have messaged the mailing group about the issues i have


From jt at toerring.de  Sun May 12 17:56:38 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 12 May 2013 21:56:38 GMT
Subject: in need of some help...
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>
	<av7ugtF8ptkU1@mid.uni-berlin.de>
	<mailman.1583.1368374425.3114.python-list@python.org>
Message-ID: <avahgmFq455U1@mid.uni-berlin.de>

Chris ?Kwpolska? Warrick <kwpolska at gmail.com> wrote:
> (slightly offtopic, sorry.)

> On Sun, May 12, 2013 at 12:20 AM, Jens Thoms Toerring <jt at toerring.de> wrote:
> > PS: If I may ask you a favor: consider refraining from using Google's
> >     completely broken interface to newsgroups - your post consists
> >     of nearly 200 lines of text containing all I wrote, with an empty
> >     line inserted between each of them, and a single line of text
> >     you wrote. It's rather annoying to have to sieve through that
> >     much of unrelated stuff just to find thar one line that's re-
> >     levant.

> Gmail automatically hides long quotes.  This is helpful in situations
> like this one.  More mail software should implement that
> functionality.  Seriously: once you go Gmail, you never go back.

i giess you mean Gougle groups and not Gmail, which I can't comment
on since I don't use it.

You still have to "un-hide" the message when you want to under-
stand what the other person is respoding to. And then you're back
to square one (and the double-spacing issue seems to remain). That
is why it has been a good tradition to remove everything when
you reply that isn't relevant to what you're replying to. Of
course, with the sorry excuse for an editor you habe in a web
based form that's more difficult to do than with a real editor.
That's one of the reasons I would advice to use a specialized
program that can be made to use the editor of your choice.

Another extremly annoying thing when reading via Google groups is
that there's no reasonable threading, i.e. it's not immediately
obvious what is meant as a reply to a specific post. That makes
Google groups basically useless for longer discussions.

And then Google groups overflow with spam messages that any
self-respecting news server would discard, so you never get
to see them.

> >             And this Google groups crap seems to make it nearly
> >     impossible to do it any other way. If you don't believe me see
> >     e.g.
> >
> >       http://wiki.python.org/moin/GoogleGroupsPython
> >
> >     There are much better alternatives to "Google groups",
> >     using a real usenet news server and a program that does
> >     not mess up content of news group postings. They've been
> >     developed with 30 years of experience with newsgroups.

> Or something even better: a mailing list.
> http://mail.python.org/mailman/listinfo/python-list is where you can
> find it.  Much friendlier than Usenet, and the software itself is
> developed by the FLUFL.

Mailing lists are quite fine and I'm on quite a number of them.
But I don't want many more to further fill up my inbox. And there
you again have the problem that there's no reasonable threading
of messages when these messages arrive in your mail folder.

> >     If I'd be conspiracy theorist I would conclude that Google
> >     is up to something bad in trying to make using newsgroups
> >     nearly impossible by their badly broken stuff (and, to add
> >     credibility to such a claim, their complete disregard for
> >     all the criticism they got over the years, actually making
> >     each version of Google groups even worse), but it's rather
> >     likely just another case of pure incompetence (or a "why
> >     should we care" attitude:-(

> They shouldn?t care because Usenet users often yell ?Get off my
> lawn!?.  Young people don?t use newsgroups.  They don?t even know what
> Usenet is.

Well, it's a pity when younger people don't use newsgroups (no
idea if this is true, though) since they can be extremely useful
for all kinds of purposes - I e.g. learned a huge amount from
just lurking. And while some groups may be nicer than others,
that's no excuse for Google at all to actively trying to destroy
them. I'd rather prefer Google to simply get rid of Google groups
and put the long time archives they obtained from DajaNews into
better hands that do care.
                               Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From rosuav at gmail.com  Sun May 12 18:18:05 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 13 May 2013 08:18:05 +1000
Subject: in need of some help...
In-Reply-To: <avahgmFq455U1@mid.uni-berlin.de>
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<mailman.1201.1367360008.3114.python-list@python.org>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>
	<av7ugtF8ptkU1@mid.uni-berlin.de>
	<mailman.1583.1368374425.3114.python-list@python.org>
	<avahgmFq455U1@mid.uni-berlin.de>
Message-ID: <CAPTjJmrsSrLZnZH0tG8SYraUn=2ctFU79im40hKC7f5A_fy_Pg@mail.gmail.com>

On Mon, May 13, 2013 at 7:56 AM, Jens Thoms Toerring <jt at toerring.de> wrote:
> Chris ?Kwpolska? Warrick <kwpolska at gmail.com> wrote:
>> Gmail automatically hides long quotes.  This is helpful in situations
>> like this one.  More mail software should implement that
>> functionality.  Seriously: once you go Gmail, you never go back.
>
> i giess you mean Gougle groups and not Gmail, which I can't comment
> on since I don't use it.
>

No, Chris (not me, the other Chris... *an*other Chris.... okay, one of
the chorus of Chrises of this list!) did mean Gmail, the Google
webmail client. It does threading (and does it better than
SquirrelMail does), and it does the hiding of long quotes, long
signatures, etc.

ChrisA


From rosuav at gmail.com  Sun May 12 20:51:38 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 13 May 2013 10:51:38 +1000
Subject: in need of some help...
In-Reply-To: <iea0p8h26s6gbhaejfai63mp8kf1cj3aen@invalid.netcom.com>
References: <001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>
	<av7ugtF8ptkU1@mid.uni-berlin.de>
	<mailman.1583.1368374425.3114.python-list@python.org>
	<avahgmFq455U1@mid.uni-berlin.de>
	<CAPTjJmrsSrLZnZH0tG8SYraUn=2ctFU79im40hKC7f5A_fy_Pg@mail.gmail.com>
	<iea0p8h26s6gbhaejfai63mp8kf1cj3aen@invalid.netcom.com>
Message-ID: <CAPTjJmoGQfPePQn4PrOv0BAMsfZR1BvJOktxde7yiU3H1=Wpeg@mail.gmail.com>

On Mon, May 13, 2013 at 9:47 AM, Dennis Lee Bieber
<wlfraed at ix.netcom.com> wrote:
> On Mon, 13 May 2013 08:18:05 +1000, Chris Angelico <rosuav at gmail.com>
> declaimed the following in gmane.comp.python.general:
>
>>
>> No, Chris (not me, the other Chris... *an*other Chris.... okay, one of
>> the chorus of Chrises of this list!) did mean Gmail, the Google
>
>         Is that the accepted group noun? I'd think a "crisis of Chrises" is
> more alliterative...

That works too! I automatically went for "chorus" since I work in
theatre, but I like your version. What do the other Chrises think?

ChrisA


From greg.ewing at canterbury.ac.nz  Mon May 13 04:10:30 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Mon, 13 May 2013 20:10:30 +1200
Subject: in need of some help...
In-Reply-To: <mailman.1607.1368402440.3114.python-list@python.org>
References: <001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>	<mailman.1202.1367363021.3114.python-list@python.org>	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>	<aucfb0F61jrU1@mid.uni-berlin.de>	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>	<av7ugtF8ptkU1@mid.uni-berlin.de>	<mailman.1583.1368374425.3114.python-list@python.org>	<avahgmFq455U1@mid.uni-berlin.de>	<CAPTjJmrsSrLZnZH0tG8SYraUn=2ctFU79im40hKC7f5A_fy_Pg@mail.gmail.com>
	<mailman.1607.1368402440.3114.python-list@python.org>
Message-ID: <avblfmF36trU1@mid.individual.net>

Dennis Lee Bieber wrote:
> 	Is that the accepted group noun? I'd think a "crisis of Chrises" is
> more alliterative...

A "confusion of Chrises" might be more appropriate
in this case.

-- 
Greg


From jt at toerring.de  Sun May 12 18:58:21 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 12 May 2013 22:58:21 GMT
Subject: in need of some help...
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>
	<av7ugtF8ptkU1@mid.uni-berlin.de>
	<mailman.1583.1368374425.3114.python-list@python.org>
	<avahgmFq455U1@mid.uni-berlin.de>
	<mailman.1599.1368397087.3114.python-list@python.org>
Message-ID: <aval4dFr96lU1@mid.uni-berlin.de>

Chris Angelico <rosuav at gmail.com> wrote:
> On Mon, May 13, 2013 at 7:56 AM, Jens Thoms Toerring <jt at toerring.de> wrote:
> > Chris ?Kwpolska? Warrick <kwpolska at gmail.com> wrote:
> >> Gmail automatically hides long quotes.  This is helpful in situations
> >> like this one.  More mail software should implement that
> >> functionality.  Seriously: once you go Gmail, you never go back.
> >
> > i giess you mean Gougle groups and not Gmail, which I can't comment
> > on since I don't use it.

> No, Chris (not me, the other Chris... *an*other Chris.... okay, one of
> the chorus of Chrises of this list!) did mean Gmail, the Google
> webmail client. It does threading (and does it better than
> SquirrelMail does), and it does the hiding of long quotes, long
> signatures, etc.

Ok, sorry then about that - as I said I never have used Gmail
(and don't plan using it for other reasons than usability - and
then I would hardly consider anything with a web interface for a
text medium to be very usable;-). But, as far as I understand,
Gmail is about email, so I'm a bit at a loss to understand what
got this to do with news groups and Google groups (were the post
I originally was responing to according to the header seemed to
be coming from) that I intended this to be about?

                          Best regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From rosuav at gmail.com  Sun May 12 19:08:21 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 13 May 2013 09:08:21 +1000
Subject: in need of some help...
In-Reply-To: <aval4dFr96lU1@mid.uni-berlin.de>
References: <1bdc367a-4187-440b-85a8-de69360bc71d@googlegroups.com>
	<001fe0f1-9124-4cbb-bc84-1b58ee7b8138@googlegroups.com>
	<mailman.1202.1367363021.3114.python-list@python.org>
	<47292460-b601-47e7-bdba-ccdc5f0d1c27@googlegroups.com>
	<aucfb0F61jrU1@mid.uni-berlin.de>
	<ca3b5132-73fa-452c-992f-94345793aa14@googlegroups.com>
	<av7ugtF8ptkU1@mid.uni-berlin.de>
	<mailman.1583.1368374425.3114.python-list@python.org>
	<avahgmFq455U1@mid.uni-berlin.de>
	<mailman.1599.1368397087.3114.python-list@python.org>
	<aval4dFr96lU1@mid.uni-berlin.de>
Message-ID: <CAPTjJmrWOyNEiUVwZCe42F+bGTnAd1M_iXx8zL1K_4zNoKcEPQ@mail.gmail.com>

On Mon, May 13, 2013 at 8:58 AM, Jens Thoms Toerring <jt at toerring.de> wrote:
> Chris Angelico <rosuav at gmail.com> wrote:
>> On Mon, May 13, 2013 at 7:56 AM, Jens Thoms Toerring <jt at toerring.de> wrote:
>> > Chris ?Kwpolska? Warrick <kwpolska at gmail.com> wrote:
>> >> Gmail automatically hides long quotes.  This is helpful in situations
>> >> like this one.  More mail software should implement that
>> >> functionality.  Seriously: once you go Gmail, you never go back.
>> >
>> > i giess you mean Gougle groups and not Gmail, which I can't comment
>> > on since I don't use it.
>
>> No, Chris (not me, the other Chris... *an*other Chris.... okay, one of
>> the chorus of Chrises of this list!) did mean Gmail, the Google
>> webmail client. It does threading (and does it better than
>> SquirrelMail does), and it does the hiding of long quotes, long
>> signatures, etc.
>
> Ok, sorry then about that - as I said I never have used Gmail
> (and don't plan using it for other reasons than usability - and
> then I would hardly consider anything with a web interface for a
> text medium to be very usable;-). But, as far as I understand,
> Gmail is about email, so I'm a bit at a loss to understand what
> got this to do with news groups and Google groups (were the post
> I originally was responing to according to the header seemed to
> be coming from) that I intended this to be about?

Since you can subscribe to the mailing list python-list at python.org and
get all of comp.lang.python (sans a pile of spam), you can read it as
a threaded mailing list instead of a newsgroup. It comes to pretty
much the same thing, so effectively you get your choice of technology.

ChrisA


From razpeitia at gmail.com  Wed May  1 02:26:06 2013
From: razpeitia at gmail.com (Ricardo Azpeitia Pimentel)
Date: Wed, 1 May 2013 01:26:06 -0500
Subject: Why chunks is not part of the python standard lib?
Message-ID: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>

After reading How do you split a list into evenly sized chunks in
Python?<http://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks-in-python>
 and seeing this kind of mistakes happening
https://code.djangoproject.com/ticket/18972 all the time.

Why is not a chunks function in itertools?

grouper from http://docs.python.org/2/library/itertools.html#recipes doesn't
have the same behavior as chunks

Example:

chunks([1, 2, 3, 4, 5], 3)# Should return [[1, 2, 3], [4, 5]] or the
iterator equivalent.

Original Post on StackOverflow:
http://stackoverflow.com/questions/16313008/why-chunks-is-not-part-of-the-python-standard-lib
-------------- next part --------------
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From breamoreboy at yahoo.co.uk  Wed May  1 03:10:11 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 01 May 2013 08:10:11 +0100
Subject: Why chunks is not part of the python standard lib?
In-Reply-To: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
Message-ID: <klqf4g$ekd$1@ger.gmane.org>

On 01/05/2013 07:26, Ricardo Azpeitia Pimentel wrote:
> After reading How do you split a list into evenly sized chunks in
> Python?
> <http://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks-in-python>
> and seeing this kind of mistakes happening
> https://code.djangoproject.com/ticket/18972 all the time.
>
> Why is not a |chunks| function in itertools?
>
> |grouper| from
> http://docs.python.org/2/library/itertools.html#recipes doesn't have the
> same behavior as |chunks |
>
> Example:
> |
>
> |chunks([1,  2,  3,  4,  5],  3)
> # Should return [[1, 2, 3], [4, 5]] or the iterator equivalent.|
>
> |Original Post on StackOverflow:
> http://stackoverflow.com/questions/16313008/why-chunks-is-not-part-of-the-python-standard-lib
>
>

Asked and answered a trillion times.  There's no concensus on how chucks 
should behave.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From oscar.j.benjamin at gmail.com  Wed May  1 05:00:04 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Wed, 1 May 2013 10:00:04 +0100
Subject: Why chunks is not part of the python standard lib?
In-Reply-To: <klqf4g$ekd$1@ger.gmane.org>
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<klqf4g$ekd$1@ger.gmane.org>
Message-ID: <CAHVvXxSctkcY5idLg6XSa9NKgLexoSh3P63s4u-_PR1gQUj9jA@mail.gmail.com>

On 1 May 2013 08:10, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 01/05/2013 07:26, Ricardo Azpeitia Pimentel wrote:
>>
>> After reading How do you split a list into evenly sized chunks in
>> Python?
>>
>> <http://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks-in-python>
>>
>> and seeing this kind of mistakes happening
>> https://code.djangoproject.com/ticket/18972 all the time.
>>
>> Why is not a |chunks| function in itertools?
>>
>> |grouper| from
>> http://docs.python.org/2/library/itertools.html#recipes doesn't have the
>> same behavior as |chunks |
>>
>> Example:
>> |
>>
>> |chunks([1,  2,  3,  4,  5],  3)
>> # Should return [[1, 2, 3], [4, 5]] or the iterator equivalent.|
>>
>> |Original Post on StackOverflow:
>>
>> http://stackoverflow.com/questions/16313008/why-chunks-is-not-part-of-the-python-standard-lib
>>
>
> Asked and answered a trillion times.  There's no concensus on how chucks
> should behave.

I'm not sure that's a valid argument against it since a chunks
function could just do a different thing depending on the arguments
given.

The issue is around how to deal with the last chunk if it isn't the
same length as the others and I can only think of 4 reasonable
responses:

1) Yield a shorter chunk
2) Extend the chunk with fill values
3) Raise an error
4) Ignore the last chunk

Cases 2 and 4 can be achieved with current itertools primitives e.g.:
2) izip_longest(fillvalue=fillvalue, *[iter(iterable)] * n)
4) zip(*[iter(iterable)] * n)

However I have only ever had use cases for 1 and 3 and these are not
currently possible without something additional (e.g. a generator
function).

In any case a chunks function can simply take arguments to give all 4
behaviours:

def chunks(iterable, chunksize, uneven='return_short', fillvalue=None):
   # loop through yielding all even chunks
   # and then
   if uneven == 'return_short:
      yield chunk
   elif uneven == 'raise':
      raise ValueError('No items left')
   elif uneven == 'fill':
      yield chunk + [fillvalue] * (chunksize - len(chunk))
   elif uneven == 'ignore':
      pass


Oscar


From breamoreboy at yahoo.co.uk  Wed May  1 09:06:15 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 01 May 2013 14:06:15 +0100
Subject: Why chunks is not part of the python standard lib?
In-Reply-To: <CAHVvXxSctkcY5idLg6XSa9NKgLexoSh3P63s4u-_PR1gQUj9jA@mail.gmail.com>
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<klqf4g$ekd$1@ger.gmane.org>
	<CAHVvXxSctkcY5idLg6XSa9NKgLexoSh3P63s4u-_PR1gQUj9jA@mail.gmail.com>
Message-ID: <klr405$ona$1@ger.gmane.org>

On 01/05/2013 10:00, Oscar Benjamin wrote:
> On 1 May 2013 08:10, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>> On 01/05/2013 07:26, Ricardo Azpeitia Pimentel wrote:
>>>
>>> After reading How do you split a list into evenly sized chunks in
>>> Python?
>>>
>>> <http://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks-in-python>
>>>
>>> and seeing this kind of mistakes happening
>>> https://code.djangoproject.com/ticket/18972 all the time.
>>>
>>> Why is not a |chunks| function in itertools?
>>>
>>> |grouper| from
>>> http://docs.python.org/2/library/itertools.html#recipes doesn't have the
>>> same behavior as |chunks |
>>>
>>> Example:
>>> |
>>>
>>> |chunks([1,  2,  3,  4,  5],  3)
>>> # Should return [[1, 2, 3], [4, 5]] or the iterator equivalent.|
>>>
>>> |Original Post on StackOverflow:
>>>
>>> http://stackoverflow.com/questions/16313008/why-chunks-is-not-part-of-the-python-standard-lib
>>>
>>
>> Asked and answered a trillion times.  There's no concensus on how chucks
>> should behave.
>
> I'm not sure that's a valid argument against it since a chunks
> function could just do a different thing depending on the arguments
> given.
>
> The issue is around how to deal with the last chunk if it isn't the
> same length as the others and I can only think of 4 reasonable
> responses:
>
> 1) Yield a shorter chunk
> 2) Extend the chunk with fill values
> 3) Raise an error
> 4) Ignore the last chunk
>
> Cases 2 and 4 can be achieved with current itertools primitives e.g.:
> 2) izip_longest(fillvalue=fillvalue, *[iter(iterable)] * n)
> 4) zip(*[iter(iterable)] * n)
>
> However I have only ever had use cases for 1 and 3 and these are not
> currently possible without something additional (e.g. a generator
> function).
>
> In any case a chunks function can simply take arguments to give all 4
> behaviours:
>
> def chunks(iterable, chunksize, uneven='return_short', fillvalue=None):
>     # loop through yielding all even chunks
>     # and then
>     if uneven == 'return_short:
>        yield chunk
>     elif uneven == 'raise':
>        raise ValueError('No items left')
>     elif uneven == 'fill':
>        yield chunk + [fillvalue] * (chunksize - len(chunk))
>     elif uneven == 'ignore':
>        pass
>
>
> Oscar
>

All that's needed to get this into the standard library is to overcome 
this quote "This has been rejected before." from 
http://bugs.python.org/issue6021#msg87745

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Thu May  2 01:15:38 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 02 May 2013 05:15:38 GMT
Subject: Why chunks is not part of the python standard lib?
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<klqf4g$ekd$1@ger.gmane.org>
	<mailman.1213.1367398827.3114.python-list@python.org>
Message-ID: <5181f679$0$29882$c3e8da3$5496439d@news.astraweb.com>

On Wed, 01 May 2013 10:00:04 +0100, Oscar Benjamin wrote:

> On 1 May 2013 08:10, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>> On 01/05/2013 07:26, Ricardo Azpeitia Pimentel wrote:
>>>
>>> After reading How do you split a list into evenly sized chunks in
>>> Python?
>>>
>>> <http://stackoverflow.com/questions/312443/how-do-you-split-a-list-
into-evenly-sized-chunks-in-python>
>>>
>>> and seeing this kind of mistakes happening
>>> https://code.djangoproject.com/ticket/18972 all the time.

That bug is irrelevant to the question about chunking a sequence or 
iterator.


>>> Why is not a |chunks| function in itertools?
[...]
>> Asked and answered a trillion times.  There's no concensus on how
>> chucks should behave.
> 
> I'm not sure that's a valid argument against it since a chunks function
> could just do a different thing depending on the arguments given.

Yes, but that's a rubbish API. I'd rather have five separate functions. 
Or maybe five methods on a single Chunker object.

I think the real reasons it's not in the standard library are:

- there's no consensus on what chunking should do;

- hence whatever gets added will disappoint some people;

- unless you add "all of them", in which case you've now got a 
significantly harder API ("there are five chunk functions in itertools, 
which should I use?"); 

- and none of them are actually very hard to write.


So the prospect of adding chunks somewhere is unattractive: lots of angst 
for very little benefit. Yes, it could be done, but none of the Python 
developers, and especially not the itertools "owner", Raymond Hettinger, 
think that the added complication is worth the benefit.


> The issue is around how to deal with the last chunk if it isn't the same
> length as the others and I can only think of 4 reasonable responses:

That's not the only issue. What does chunking (grouping) even mean? Given:

chunk("abcdef", 3)

should I get this?  [abc, def]

or this?  [abc, bcd, cde, def]


There are good use-cases for both.

If given a string, should chunking re-join the individual characters into 
strings, or leave them as lists of chars? Tuples of chars? E.g.

chunk("abcdef", 3) => "abc" ...

or ["a", "b", "c"] ...

How about bytes?

I have opinions on these questions, but I'm not going to give them to 
you. The point is that chunking means different things to different 
people. If you write your own, you get to pick whatever behaviour you 
like, instead of trying to satisfy everyone.


> 1) Yield a shorter chunk
> 2) Extend the chunk with fill values
> 3) Raise an error
> 4) Ignore the last chunk
> 
> Cases 2 and 4 can be achieved with current itertools primitives e.g.: 2)
> izip_longest(fillvalue=fillvalue, *[iter(iterable)] * n) 4)
> zip(*[iter(iterable)] * n)
> 
> However I have only ever had use cases for 1 and 3 and these are not
> currently possible without something additional (e.g. a generator
> function).

All of these are trivial. Start with the grouper recipe from the itertools 
documentation, which is your case 2) above, renaming if desired:

http://docs.python.org/2/library/itertools.html#recipes


def chunk_pad(n, iterable, fillvalue=None):
    args = [iter(iterable)] * n
    return izip_longest(fillvalue=fillvalue, *args)


Now define:


def chunk_short(n, iterable):  # Case 1) above
    sentinel = object()
    for chunk in chunk_pad(n, iterable, fillvalue=sentinel):
        if sentinel not in chunk:
            yield chunk
        else:
            i = chunk.index(sentinel)
            yield chunk[:i]


def chunk_strict(n, iterable):  # Case 3) above
    sentinel = object()
    for chunk in chunk_pad(n, iterable, fillvalue=sentinel):
        if sentinel in chunk:
            raise ValueError
        yield chunk


def chunk(n, iterable):  # Case 4) above
    args = [iter(iterable)]*n
    return izip(*args)


def chunk_other(n, iterable):  # I suck at thinking up names...
    it = iter(iterable)
    values = [next(it) for _ in range(n)]  # What if this is short?
    while True:
        yield tuple(values)
        values.pop(0)
        try:
            values.append(next(it))
        except StopIteration:
            break
        

-- 
Steven


From wolfgang.maier at biologie.uni-freiburg.de  Thu May  2 04:53:50 2013
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Thu, 2 May 2013 08:53:50 +0000 (UTC)
Subject: Why chunks is not part of the python standard lib?
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<klqf4g$ekd$1@ger.gmane.org>
	<mailman.1213.1367398827.3114.python-list@python.org>
	<5181f679$0$29882$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <loom.20130502T101804-814@post.gmane.org>

Steven D'Aprano <steve+comp.lang.python <at> pearwood.info> writes:

>
> > 1) Yield a shorter chunk
> > 2) Extend the chunk with fill values
> > 3) Raise an error
> > 4) Ignore the last chunk
> > 
> > Cases 2 and 4 can be achieved with current itertools primitives e.g.: 2)
> > izip_longest(fillvalue=fillvalue, *[iter(iterable)] * n) 4)
> > zip(*[iter(iterable)] * n)
> > 
> > However I have only ever had use cases for 1 and 3 and these are not
> > currently possible without something additional (e.g. a generator
> > function).
> 
> All of these are trivial. Start with the grouper recipe from the itertools 
> documentation, which is your case 2) above, renaming if desired:
> 
> http://docs.python.org/2/library/itertools.html#recipes
> 
> def chunk_pad(n, iterable, fillvalue=None):
>     args = [iter(iterable)] * n
>     return izip_longest(fillvalue=fillvalue, *args)
> 
> Now define:
> 
> def chunk_short(n, iterable):  # Case 1) above
>     sentinel = object()
>     for chunk in chunk_pad(n, iterable, fillvalue=sentinel):
>         if sentinel not in chunk:
>             yield chunk
>         else:
>             i = chunk.index(sentinel)
>             yield chunk[:i]
> 
> def chunk_strict(n, iterable):  # Case 3) above
>     sentinel = object()
>     for chunk in chunk_pad(n, iterable, fillvalue=sentinel):
>         if sentinel in chunk:
>             raise ValueError
>         yield chunk
> 

These are only trivial on the surface. I brought up this topic on
python-ideas just weeks ago and it turns out there's a surprising numbers of
alternate solutions that people use for these two cases. Yours is
straightforward and simple, but comes at the price of the if sentinel clause
being checked repeatedly. An optimized version suggested by Peter Otten
replaces your for loop by:

chunk_pad = zip_longest(*args, fillvalue=fillvalue)
prev = next(chunks)

for chunk in chunk_pad:
    yield prev
    prev = chunk

then doing the sentinel test only once at the end.

>> 1) Yield a shorter chunk
>> 2) Extend the chunk with fill values
>> 3) Raise an error
>> 4) Ignore the last chunk
>> 
>> Cases 2 and 4 can be achieved with current itertools primitives e.g.: 2)
>> izip_longest(fillvalue=fillvalue, *[iter(iterable)] * n) 4)
>> zip(*[iter(iterable)] * n)

In my opinion, it would make sense to have the 4 cases suggested by Oscar
covered by itertools. As he says, cases 2 and 4 are already (and there is
the grouper recipe in itertools giving the solution for case 2). It would
prevent people from reinventing (often suboptimal) solutions to these common
problems and it would bring a speed-gain even compared to the best Python
implementations since things would be coded in C.

I would advocate for either of the following two solutions:

a) have an extra 'mode'-type argument for zip_longest() to control its
behavior (default mode could be the current fillvalue padding, 'strict' mode
would raise an error, and 'relaxed' mode would yield the shorter chunk.
or
b) have extra zip_strict and zip_relaxed (I'm also not too good at thinking
up names :)) functions in itertools

Either way, you could now very easily modify the existing grouper recipe in
itertools to implement the four different 'chunks' functions (I would keep
calling them 'grouper' functions in line with the current itertools version).

> I think the real reasons it's not in the standard library are:
> 
> - there's no consensus on what chunking should do;
> 
> - hence whatever gets added will disappoint some people;
> 
> - unless you add "all of them", in which case you've now got a 
> significantly harder API ("there are five chunk functions in itertools, 
> which should I use?");
>
> What does chunking (grouping) even mean? Given:
> 
> chunk("abcdef", 3)
> 
> should I get this?  [abc, def]
> 
> or this?  [abc, bcd, cde, def]

I guess this suggestion would not compromise the API too much, after all,
all these zip versions would still behave like a zip() function should.
Itertools users would also know what a 'grouper' recipe does, i.e., it
doesn't do the fancier alternative stuff you suggest like rejoining groups
of characters obtained from a string. So this would be a relatively
conservative addition.

What do you think?
Wolfgang



From breamoreboy at yahoo.co.uk  Thu May  2 05:23:57 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 02 May 2013 10:23:57 +0100
Subject: Why chunks is not part of the python standard lib?
In-Reply-To: <loom.20130502T101804-814@post.gmane.org>
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<klqf4g$ekd$1@ger.gmane.org>
	<mailman.1213.1367398827.3114.python-list@python.org>
	<5181f679$0$29882$c3e8da3$5496439d@news.astraweb.com>
	<loom.20130502T101804-814@post.gmane.org>
Message-ID: <kltbbd$jn5$1@ger.gmane.org>

On 02/05/2013 09:53, Wolfgang Maier wrote:
>
> What do you think?
> Wolfgang
>

It ain't gonna happen, unless somebody puts Raymond Hettinger in the 
Comfy Chair :)

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From oscar.j.benjamin at gmail.com  Thu May  2 08:52:16 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 2 May 2013 13:52:16 +0100
Subject: Why chunks is not part of the python standard lib?
In-Reply-To: <5181f679$0$29882$c3e8da3$5496439d@news.astraweb.com>
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<klqf4g$ekd$1@ger.gmane.org>
	<mailman.1213.1367398827.3114.python-list@python.org>
	<5181f679$0$29882$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAHVvXxQQXLvSSMCp=WEEUpc-RjULQinfxAJn=Gqzg2HP7=t=3g@mail.gmail.com>

On 2 May 2013 06:15, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Wed, 01 May 2013 10:00:04 +0100, Oscar Benjamin wrote:
>>
>> I'm not sure that's a valid argument against it since a chunks function
>> could just do a different thing depending on the arguments given.
>
> Yes, but that's a rubbish API. I'd rather have five separate functions.
> Or maybe five methods on a single Chunker object.

Fair enough.

[snip]
> - and none of them are actually very hard to write.

They are all easy to write as generator functions but to me the point
of itertools is that you can do things more efficiently than a
generator function. Otherwise code that uses a combination of
itertools primitives is usually harder to understand than an
equivalent generator function so I'd probably avoid using itertools.

> So the prospect of adding chunks somewhere is unattractive: lots of angst
> for very little benefit. Yes, it could be done, but none of the Python
> developers, and especially not the itertools "owner", Raymond Hettinger,
> think that the added complication is worth the benefit.

It's not necessarily that chunks should be added but that it would be
good if itertools had the necessary primitives to be able to achieve
something like chunks without a generator function. As Wolfgang says
zip() and zip_longest() are only 2 of the 4 obvious types of zipping
and correspond to the 2 of the 4 obvious types of chunks() that can be
done with itertools primitives.

>> The issue is around how to deal with the last chunk if it isn't the same
>> length as the others and I can only think of 4 reasonable responses:
>
> That's not the only issue. What does chunking (grouping) even mean? Given:
>
> chunk("abcdef", 3)
>
> should I get this?  [abc, def]
>
> or this?  [abc, bcd, cde, def]

I don't think many people expect that. In any case that type of
chunking is already possible using itertools.

> There are good use-cases for both.
>
> If given a string, should chunking re-join the individual characters into
> strings, or leave them as lists of chars? Tuples of chars? E.g.
>
> chunk("abcdef", 3) => "abc" ...
>
> or ["a", "b", "c"] ...
>
> How about bytes?

It should be tuples or lists. Anything in itertools should just treat
everything as iterators/iterables and not alter its behaviour for
different types of sequences.

>> 1) Yield a shorter chunk
>> 2) Extend the chunk with fill values
>> 3) Raise an error
>> 4) Ignore the last chunk
>>
>> Cases 2 and 4 can be achieved with current itertools primitives e.g.: 2)
>> izip_longest(fillvalue=fillvalue, *[iter(iterable)] * n) 4)
>> zip(*[iter(iterable)] * n)
>>
>> However I have only ever had use cases for 1 and 3 and these are not
>> currently possible without something additional (e.g. a generator
>> function).
>
> All of these are trivial. Start with the grouper recipe from the itertools
> documentation, which is your case 2) above, renaming if desired:
>
> http://docs.python.org/2/library/itertools.html#recipes
>
[snip]
>
> def chunk_short(n, iterable):  # Case 1) above
>     sentinel = object()
>     for chunk in chunk_pad(n, iterable, fillvalue=sentinel):
>         if sentinel not in chunk:

The point is it would be good if you could avoid the check in the line
above and the overhead of having an if statement and a generator frame
between every next call. You can do better by writing the line above
as
    if chunk[-1] is not sentinel
but it is still a redundant check. zip_relaxed() would know when
StopIteration was raised and wouldn't need to retrospectively check
every chunk.

>             yield chunk
>         else:
>             i = chunk.index(sentinel)
>             yield chunk[:i]
>
>
> def chunk_strict(n, iterable):  # Case 3) above
>     sentinel = object()
>     for chunk in chunk_pad(n, iterable, fillvalue=sentinel):
>         if sentinel in chunk:

if chunk[-1] is sentinel

>             raise ValueError
>         yield chunk
>
>
> def chunk(n, iterable):  # Case 4) above
>     args = [iter(iterable)]*n
>     return izip(*args)
>
>
> def chunk_other(n, iterable):  # I suck at thinking up names...
>     it = iter(iterable)
>     values = [next(it) for _ in range(n)]  # What if this is short?
>     while True:
>         yield tuple(values)
>         values.pop(0)
>         try:
>             values.append(next(it))
>         except StopIteration:
>             break

You can do this one somewhat wastefully with itertools instead of a
generator function:

def chunk_other(n, iterable):
    iterators = tee(iterable, n)
    for n, it in enumerate(iterators):
        for _ in range(n):
            try:
                next(it)
            except StopIteration:
                return iter([])
    return izip(*iterators)

I don't know which of those two would be faster but it's certainly
easier to understand the generator function.


Oscar


From rosuav at gmail.com  Thu May  2 08:55:50 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 2 May 2013 22:55:50 +1000
Subject: Why chunks is not part of the python standard lib?
In-Reply-To: <CAHVvXxQQXLvSSMCp=WEEUpc-RjULQinfxAJn=Gqzg2HP7=t=3g@mail.gmail.com>
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<klqf4g$ekd$1@ger.gmane.org>
	<mailman.1213.1367398827.3114.python-list@python.org>
	<5181f679$0$29882$c3e8da3$5496439d@news.astraweb.com>
	<CAHVvXxQQXLvSSMCp=WEEUpc-RjULQinfxAJn=Gqzg2HP7=t=3g@mail.gmail.com>
Message-ID: <CAPTjJmqv8q3Xe=eFUfd+O4nhSEFg6pMJErwG9q6rM1qEyOuJ2A@mail.gmail.com>

On Thu, May 2, 2013 at 10:52 PM, Oscar Benjamin
<oscar.j.benjamin at gmail.com> wrote:
> They are all easy to write as generator functions but to me the point
> of itertools is that you can do things more efficiently than a
> generator function. Otherwise code that uses a combination of
> itertools primitives is usually harder to understand than an
> equivalent generator function so I'd probably avoid using itertools.

Aren't most of the itertools primitives written in Python anyway? If
your code is harder to understand, just write the generator function!

ChrisA


From oscar.j.benjamin at gmail.com  Thu May  2 09:23:57 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 2 May 2013 14:23:57 +0100
Subject: Why chunks is not part of the python standard lib?
In-Reply-To: <CAPTjJmqv8q3Xe=eFUfd+O4nhSEFg6pMJErwG9q6rM1qEyOuJ2A@mail.gmail.com>
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<klqf4g$ekd$1@ger.gmane.org>
	<mailman.1213.1367398827.3114.python-list@python.org>
	<5181f679$0$29882$c3e8da3$5496439d@news.astraweb.com>
	<CAHVvXxQQXLvSSMCp=WEEUpc-RjULQinfxAJn=Gqzg2HP7=t=3g@mail.gmail.com>
	<CAPTjJmqv8q3Xe=eFUfd+O4nhSEFg6pMJErwG9q6rM1qEyOuJ2A@mail.gmail.com>
Message-ID: <CAHVvXxTsM9z1LHSu+YzHEW9teVYeVrDF_wJ2-Ex3N5jkr02Q4Q@mail.gmail.com>

On 2 May 2013 13:55, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, May 2, 2013 at 10:52 PM, Oscar Benjamin
> <oscar.j.benjamin at gmail.com> wrote:
>> They are all easy to write as generator functions but to me the point
>> of itertools is that you can do things more efficiently than a
>> generator function. Otherwise code that uses a combination of
>> itertools primitives is usually harder to understand than an
>> equivalent generator function so I'd probably avoid using itertools.
>
> Aren't most of the itertools primitives written in Python anyway? If
> your code is harder to understand, just write the generator function!

The documentation describes them by showing equivalent generator
functions and there may be a pure Python version of the module but if
you look here then you can see which are builtin for CPython:

http://hg.python.org/cpython/file/c3656dca65e7/Modules/itertoolsmodule.c#l4070

The list covers all of the documented itertools functions (actually I
now realise that they're mostly types not functions).


Oscar


From wolfgang.maier at biologie.uni-freiburg.de  Thu May  2 10:02:06 2013
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Thu, 2 May 2013 14:02:06 +0000 (UTC)
Subject: Why chunks is not part of the python standard lib?
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<klqf4g$ekd$1@ger.gmane.org>
	<mailman.1213.1367398827.3114.python-list@python.org>
	<5181f679$0$29882$c3e8da3$5496439d@news.astraweb.com>
	<CAHVvXxQQXLvSSMCp=WEEUpc-RjULQinfxAJn=Gqzg2HP7=t=3g@mail.gmail.com>
	<CAPTjJmqv8q3Xe=eFUfd+O4nhSEFg6pMJErwG9q6rM1qEyOuJ2A@mail.gmail.com>
	<CAHVvXxTsM9z1LHSu+YzHEW9teVYeVrDF_wJ2-Ex3N5jkr02Q4Q@mail.gmail.com>
Message-ID: <loom.20130502T154128-823@post.gmane.org>

Oscar Benjamin <oscar.j.benjamin <at> gmail.com> writes:

> 
> On 2 May 2013 13:55, Chris Angelico <rosuav <at> gmail.com> wrote:
> > On Thu, May 2, 2013 at 10:52 PM, Oscar Benjamin
> > <oscar.j.benjamin <at> gmail.com> wrote:
> >> They are all easy to write as generator functions but to me the point
> >> of itertools is that you can do things more efficiently than a
> >> generator function. Otherwise code that uses a combination of
> >> itertools primitives is usually harder to understand than an
> >> equivalent generator function so I'd probably avoid using itertools.
> >
> > Aren't most of the itertools primitives written in Python anyway? If
> > your code is harder to understand, just write the generator function!
> 
> The documentation describes them by showing equivalent generator
> functions and there may be a pure Python version of the module but if
> you look here then you can see which are builtin for CPython:
> 
> http://hg.python.org/cpython/file/c3656dca65e7/Modules/itertoolsmodule.c#l4070
> 
> The list covers all of the documented itertools functions (actually I
> now realise that they're mostly types not functions).
> 
> Oscar
> 

Maybe it's helpful to agree on terminology here.
Looks like Oscar is using *itertools primitives* for things like zip_longest()
- (I'm referring to Python3 here, where the i in zip_longest has disappeared
and the former izip() has been replaced with the built-in zip()) -
, which the docs call "a core set of fast, memory efficient tools that are
useful by themselves or in combination" and that are listed in the doc's
subsection .1 ("Itertools functions"). I think these are written in C (and
explained by giving equivalent Python code).
Then there are the *recipes* (subsection .2), which consist of Python code
that combines and uses *primitves*. Among those is the *grouper recipe*,
which is a chunks() doing fillvalue padding on the last chunk. It's obvious
that you could write an analogous *grouper* that ignores a truncated last
chunk by using zip instead of zip_longest.
Now, Oscar's and my point is that by adding two more *primitives*, call them
zip_strict and zip_relaxed or whatever you like, written in C and behaving
analogous to zip_longest, you could write analogous *grouper recipes* that
raise an error or simply yield when the last chunk is truncated. Those
*recipes* would still have Python code of course, but they would return an
iterator implemented in C.





From storchaka at gmail.com  Wed May  1 12:19:07 2013
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Wed, 01 May 2013 19:19:07 +0300
Subject: Why chunks is not part of the python standard lib?
In-Reply-To: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
Message-ID: <klrf9m$ju3$1@ger.gmane.org>

01.05.13 09:26, Ricardo Azpeitia Pimentel ???????(??):
> After reading How do you split a list into evenly sized chunks in
> Python?
> <http://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks-in-python>
> and seeing this kind of mistakes happening
> https://code.djangoproject.com/ticket/18972 all the time.
>
> Why is not a |chunks| function in itertools?

Because not every 1 line function needs to be in the standard library.

> |chunks([1,  2,  3,  4,  5],  3)
> # Should return [[1, 2, 3], [4, 5]] or the iterator equivalent.|

def chunks(seq, size):
     return [seq[i: i + size] for i in range(0, len(seq), size)]




From no.email at nospam.invalid  Wed May  1 12:30:19 2013
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 01 May 2013 09:30:19 -0700
Subject: Why chunks is not part of the python standard lib?
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
	<mailman.1219.1367425160.3114.python-list@python.org>
Message-ID: <7xy5byacis.fsf@ruckus.brouhaha.com>

Serhiy Storchaka <storchaka at gmail.com> writes:
> def chunks(seq, size):
>     return [seq[i: i + size] for i in range(0, len(seq), size)]

That's just for lists.  An itertools version would work with arbitrary
iterables.  I've also had to rewrite that function more times than seems
proper.


From fabiosantosart at gmail.com  Thu May  2 09:06:40 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 2 May 2013 14:06:40 +0100
Subject: Why chunks is not part of the python standard lib?
In-Reply-To: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
References: <CAP5i+tYC+cMtseEduTm76LXkaP1Hh-Tz-_HipO7LsURtnuwtOw@mail.gmail.com>
Message-ID: <CAA=1kxRPk2E2kxwyYteg0Uo_bWX+XFC-J-sx9MzAGgj_M0Vrog@mail.gmail.com>

>
> Why is not a chunks function in itertools?
>

It is in more-itertools.

It's not the standard library, but it's better than rolling your own every
time you need it.
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From sigzero at gmail.com  Wed May  1 08:01:52 2013
From: sigzero at gmail.com (Robert)
Date: Wed, 1 May 2013 05:01:52 -0700 (PDT)
Subject: ANN: ActivePython 3.2.2.3 is now available
In-Reply-To: <mailman.1292.1316476068.27778.python-list@python.org>
References: <mailman.1292.1316476068.27778.python-list@python.org>
Message-ID: <131044e2-3385-4cee-8019-48e52dc364b8@googlegroups.com>

Will this be the last one? It has been two years.


From kw at codebykevin.com  Wed May  1 09:52:49 2013
From: kw at codebykevin.com (Kevin Walzer)
Date: Wed, 01 May 2013 09:52:49 -0400
Subject: ANN: ActivePython 3.2.2.3 is now available
In-Reply-To: <131044e2-3385-4cee-8019-48e52dc364b8@googlegroups.com>
References: <mailman.1292.1316476068.27778.python-list@python.org>
	<131044e2-3385-4cee-8019-48e52dc364b8@googlegroups.com>
Message-ID: <klr6h7$f8v$1@dont-email.me>

On 5/1/13 8:01 AM, Robert wrote:
> Will this be the last one? It has been two years.
>

Hard to say. AS has been focusing on cloud-based stuff lately. 
ActivePerl hasn't been updated for a long time either. ActiveTcl is 
still maintained.

--Kevin

-- 
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
http://www.wtmobilesoftware.com


From J.Butler at albynschool.co.uk  Wed May  1 10:52:51 2013
From: J.Butler at albynschool.co.uk (Jennifer Butler)
Date: Wed, 1 May 2013 15:52:51 +0100
Subject: to a human - about 2to3
Message-ID: <3C8565F3435F024E9BB3B36BE06393D80120F355@albyn-exch.albyn-sch.local.co.uk>

Hiya

 

I have trawled around your various pages and haven't found what I want.

 

 

I will start teaching Python to my pupils shortly. I have been looking
for materials and have gathered a collection of programs. The problem is
they are written in v2 and I have v3 installed in my classroom. I read
about the 2to3 conversion program, but I can't get it to work.

Could you possibly give me a Noddy's guide to do this? 

 

Thanks in anticipation.

 

Jennifer J

 

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From paul.nospam at rudin.co.uk  Wed May  1 11:11:17 2013
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Wed, 01 May 2013 16:11:17 +0100
Subject: to a human - about 2to3
References: <mailman.1216.1367420096.3114.python-list@python.org>
Message-ID: <87bo8urazu.fsf@no-fixed-abode.cable.virginmedia.net>

"Jennifer Butler" <J.Butler at albynschool.co.uk> writes:

> Hiya
>
> I have trawled around your various pages and haven?t found what I
> want.
>
> I will start teaching Python to my pupils shortly. I have been looking
> for materials and have gathered a collection of programs. The problem
> is they are written in v2 and I have v3 installed in my classroom. I
> read about the 2to3 conversion program, but I can?t get it to work.
>
> Could you possibly give me a Noddy?s guide to do this?


Perhaps the first thing you should teach your students is how to ask
questions :)

When you say you "can't get it to work" what does that mean? What
exactly did you do? What happened as a result? How did that differ from
what you expected to happen or hoped would happen? Can you construct a
minimal specific example that illustrates your problem?






From rosuav at gmail.com  Wed May  1 11:25:50 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 2 May 2013 01:25:50 +1000
Subject: to a human - about 2to3
In-Reply-To: <87bo8urazu.fsf@no-fixed-abode.cable.virginmedia.net>
References: <mailman.1216.1367420096.3114.python-list@python.org>
	<87bo8urazu.fsf@no-fixed-abode.cable.virginmedia.net>
Message-ID: <CAPTjJmqZ6HsGjQfDNWk70CCB2djEtF7MeFNj=AidEF-V_zMjbw@mail.gmail.com>

On Thu, May 2, 2013 at 1:11 AM, Paul Rudin <paul.nospam at rudin.co.uk> wrote:
> "Jennifer Butler" <J.Butler at albynschool.co.uk> writes:
>
>> Hiya
>>
>> I have trawled around your various pages and haven?t found what I
>> want.
>>
>> I will start teaching Python to my pupils shortly. I have been looking
>> for materials and have gathered a collection of programs. The problem
>> is they are written in v2 and I have v3 installed in my classroom. I
>> read about the 2to3 conversion program, but I can?t get it to work.
>>
>> Could you possibly give me a Noddy?s guide to do this?
>
>
> Perhaps the first thing you should teach your students is how to ask
> questions :)

Specifically, you and your students would do well spending a couple of
sessions here:

http://www.catb.org/esr/faqs/smart-questions.html

2to3 has fairly good --help information. In my porting projects, I
started there and worked forward. Seemed to go fairly well.

ChrisA


From mail at timgolden.me.uk  Wed May  1 11:27:02 2013
From: mail at timgolden.me.uk (Tim Golden)
Date: Wed, 01 May 2013 16:27:02 +0100
Subject: to a human - about 2to3
In-Reply-To: <3C8565F3435F024E9BB3B36BE06393D80120F355@albyn-exch.albyn-sch.local.co.uk>
References: <3C8565F3435F024E9BB3B36BE06393D80120F355@albyn-exch.albyn-sch.local.co.uk>
Message-ID: <51813446.3000703@timgolden.me.uk>

On 01/05/2013 15:52, Jennifer Butler wrote:
> I will start teaching Python to my pupils shortly. I have been looking
> for materials and have gathered a collection of programs. The problem is
> they are written in v2 and I have v3 installed in my classroom. I read
> about the 2to3 conversion program, but I can?t get it to work.
> 
> Could you possibly give me a Noddy?s guide to do this?

This might be useful:

  http://python3porting.com/2to3.html

although it's not clear from your question whether you're competent
in Python and just a little unclear on 2to3 or coming new to the
whole thing and hoping that 2to3 will give you a pain-free conversion.

If it's the latter then I'm afraid your ride may be rockier than
you hoped. :(

Also, I note that you're UK-based (albeit at the other end of it from
where I am). Depending on where this thread goes you might get some
local help by posting to the python-uk mailing list:

  http://mail.python.org/mailman/listinfo/python-uk

It's a quiet list, mostly for local events and jobs, but
you might find someone in your neighbourhood (or at least in your own
country) who could give you some help.

TJG


From breamoreboy at yahoo.co.uk  Wed May  1 13:49:21 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 01 May 2013 18:49:21 +0100
Subject: to a human - about 2to3
In-Reply-To: <3C8565F3435F024E9BB3B36BE06393D80120F355@albyn-exch.albyn-sch.local.co.uk>
References: <3C8565F3435F024E9BB3B36BE06393D80120F355@albyn-exch.albyn-sch.local.co.uk>
Message-ID: <klrkj0$dp1$1@ger.gmane.org>

On 01/05/2013 15:52, Jennifer Butler wrote:
> Hiya
>
> I have trawled around your various pages and haven?t found what I want.
>
> I will start teaching Python to my pupils shortly. I have been looking
> for materials and have gathered a collection of programs. The problem is
> they are written in v2 and I have v3 installed in my classroom. I read
> about the 2to3 conversion program, but I can?t get it to work.
>
> Could you possibly give me a Noddy?s guide to do this?
>
> Thanks in anticipation.
>
> Jennifer J
>

Here's the help output.  I'd guess (as you don't specify exactly what 
doesn't work, 0/10, must try harder :) that you haven't specified -w, 
--write in which case the files don't get modified.

c:\Users\Mark\MyPython>2to3 --help
Usage: 2to3 [options] file|dir ...

Options:
   -h, --help            show this help message and exit
   -d, --doctests_only   Fix up doctests only
   -f FIX, --fix=FIX     Each FIX specifies a transformation; default: all
   -j PROCESSES, --processes=PROCESSES
                         Run 2to3 concurrently
   -x NOFIX, --nofix=NOFIX
                         Prevent a transformation from being run
   -l, --list-fixes      List available transformations
   -p, --print-function  Modify the grammar so that print() is a function
   -v, --verbose         More verbose logging
   --no-diffs            Don't show diffs of the refactoring
   -w, --write           Write back modified files
   -n, --nobackups       Don't write backups for modified files
   -o OUTPUT_DIR, --output-dir=OUTPUT_DIR
                         Put output files in this directory instead of
                         overwriting the input files.  Requires -n.
   -W, --write-unchanged-files
                         Also write files even if no changes were required
                         (useful with --output-dir); implies -w.
   --add-suffix=ADD_SUFFIX
                         Append this string to all output filenames. 
Requires
                         -n if non-empty.  ex: --add-suffix='3' will 
generate
                         .py3 files.


-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From tjreedy at udel.edu  Wed May  1 14:59:06 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Wed, 01 May 2013 14:59:06 -0400
Subject: to a human - about 2to3
In-Reply-To: <3C8565F3435F024E9BB3B36BE06393D80120F355@albyn-exch.albyn-sch.local.co.uk>
References: <3C8565F3435F024E9BB3B36BE06393D80120F355@albyn-exch.albyn-sch.local.co.uk>
Message-ID: <klrokv$ond$1@ger.gmane.org>

On 5/1/2013 10:52 AM, Jennifer Butler wrote:

> I will start teaching Python to my pupils shortly. I have been looking
> for materials and have gathered a collection of programs. The problem is
> they are written in v2 and I have v3 installed in my classroom. I read
> about the 2to3 conversion program, but I can?t get it to work.

You might find this page
http://www.python.org/community/sigs/current/edu-sig/
and the education list itself. I am sure many programs useful in 
education have already been ported.

Many simple programs, of the sort used in beginner classes need minimal 
change. Oftem 'print x' to 'print(x)' is all that is needed. 2to3 will 
do that for you, once you learn how to use it, but I have not.  For the 
programs people post on the list, with just 1 or 2 prints, I make the 
change manually in the Idle editor before running. I often want to 
change other things as well, so no big deal.



From drsalists at gmail.com  Wed May  1 19:11:12 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Wed, 1 May 2013 16:11:12 -0700
Subject: Red Black Tree implementation?
Message-ID: <CAGGBd_rsM7LVd_V=Xb64vqeXmYCx2uxAnQfJo3MsHXJOphzJBQ@mail.gmail.com>

What's the best Red Black Tree implementation for Python with an opensource
license?

I started out looking at
http://newcenturycomputers.net/projects/rbtree.htmlbecause it was
pretty high in Google and had the operators I wanted, but it
gets very slow at about half a million elements.  I've been discussing this
with a C programmer who believes that Red Black Trees should perform very
similarly to an AVL tree, but that's not at all what I'm getting with the
newcenturycomputers implementation.

I'd prefer something that looks like a dictionary, runs on 2.x and 3.x, and
passes pylint, but if that's not yet available I might make it so.

This is part of a comparison of Python tree types I did a while back...
I've been thinking that I've given Red Black Trees short shrift by using a
poor implementation.  The comparison so far is at
http://stromberg.dnsalias.org/~strombrg/python-tree-and-heap-comparison/

Thanks!
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From buzzard at invalid.invalid  Wed May  1 22:06:04 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Thu, 02 May 2013 03:06:04 +0100
Subject: Red Black Tree implementation?
In-Reply-To: <mailman.1225.1367449881.3114.python-list@python.org>
References: <mailman.1225.1367449881.3114.python-list@python.org>
Message-ID: <5181ca0e$0$13974$862e30e2@ngroups.net>

On 02/05/13 00:11, Dan Stromberg wrote:
>
> What's the best Red Black Tree implementation for Python with an
> opensource license?
>
> I started out looking at
> http://newcenturycomputers.net/projects/rbtree.html because it was
> pretty high in Google and had the operators I wanted, but it gets very
> slow at about half a million elements.  I've been discussing this with a
> C programmer who believes that Red Black Trees should perform very
> similarly to an AVL tree, but that's not at all what I'm getting with
> the newcenturycomputers implementation.
>
> I'd prefer something that looks like a dictionary, runs on 2.x and 3.x,
> and passes pylint, but if that's not yet available I might make it so.
>
> This is part of a comparison of Python tree types I did a while back...
> I've been thinking that I've given Red Black Trees short shrift by using
> a poor implementation.  The comparison so far is at
> http://stromberg.dnsalias.org/~strombrg/python-tree-and-heap-comparison/
>
> Thanks!
>
>


I have an implementation that you can try out. It's not based on any 
other implementation, so my bugs will be independent of any bugs in the 
code you're currently using. It looks more like a set - add, remove, 
discard. Not tried on Python 3 or run through pylint. I just tried 
adding a million items to a tree, and it takes about 25% longer to add 
items at the end compared to those at the beginning. Timing removals 
uncovered a bug. So if you want the code I'll fix the bug and send it 
(to your gmail e-mail address?). Cheers.

Duncan


From drsalists at gmail.com  Thu May  2 22:00:09 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Thu, 2 May 2013 19:00:09 -0700
Subject: Red Black Tree implementation?
In-Reply-To: <5181ca0e$0$13974$862e30e2@ngroups.net>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
Message-ID: <CAGGBd_rGnjfS2LUKuhd1GQwwC20rGc6vZePar=QSPpCM4dBfGw@mail.gmail.com>

On Wed, May 1, 2013 at 7:06 PM, duncan smith <buzzard at invalid.invalid>wrote:

> I have an implementation that you can try out. It's not based on any other
> implementation, so my bugs will be independent of any bugs in the code
> you're currently using. It looks more like a set - add, remove, discard.
> Not tried on Python 3 or run through pylint. I just tried adding a million
> items to a tree, and it takes about 25% longer to add items at the end
> compared to those at the beginning. Timing removals uncovered a bug. So if
> you want the code I'll fix the bug and send it (to your gmail e-mail
> address?). Cheers.
>
> Duncan
> --
> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>

What license?

Thanks!
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From buzzard at invalid.invalid  Mon May  6 20:55:20 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Tue, 07 May 2013 01:55:20 +0100
Subject: Red Black Tree implementation?
In-Reply-To: <mailman.1260.1367546417.3114.python-list@python.org>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
Message-ID: <518850f8$0$8157$862e30e2@ngroups.net>

On 03/05/13 03:00, Dan Stromberg wrote:
>
> On Wed, May 1, 2013 at 7:06 PM, duncan smith <buzzard at invalid.invalid
> <mailto:buzzard at invalid.invalid>> wrote:
>
>     I have an implementation that you can try out. It's not based on any
>     other implementation, so my bugs will be independent of any bugs in
>     the code you're currently using. It looks more like a set - add,
>     remove, discard. Not tried on Python 3 or run through pylint. I just
>     tried adding a million items to a tree, and it takes about 25%
>     longer to add items at the end compared to those at the beginning.
>     Timing removals uncovered a bug. So if you want the code I'll fix
>     the bug and send it (to your gmail e-mail address?). Cheers.
>
>     Duncan
>     --
>     http://mail.python.org/__mailman/listinfo/python-list
>     <http://mail.python.org/mailman/listinfo/python-list>
>
>
> What license?
>
> Thanks!
>

Here's the text I usually prepend.


##Copyright (c) 2013 duncan g. smith
##
##Permission is hereby granted, free of charge, to any person obtaining a
##copy of this software and associated documentation files (the "Software"),
##to deal in the Software without restriction, including without limitation
##the rights to use, copy, modify, merge, publish, distribute, sublicense,
##and/or sell copies of the Software, and to permit persons to whom the
##Software is furnished to do so, subject to the following conditions:
##
##The above copyright notice and this permission notice shall be included
##in all copies or substantial portions of the Software.
##
##THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
##OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
MERCHANTABILITY,
##FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
##THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
##OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
##ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
##OTHER DEALINGS IN THE SOFTWARE.


Basically, "do what you want with it but don't blame me if it goes tits 
up". I'm happy to consider tidying it up a bit and using a more 
recognized form of licence. Just had a bank holiday here, so bug not yet 
squashed. But it is the sort of bug that might account for what you've 
seen (if a similar bug exists in the code you've been using). The tree 
doesn't always get properly rebalanced on node removals. I'll attack the 
problem later tomorrow (technically, later today). Cheers.

Duncan


From drsalists at gmail.com  Mon May  6 21:20:08 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Mon, 6 May 2013 18:20:08 -0700
Subject: Red Black Tree implementation?
In-Reply-To: <518850f8$0$8157$862e30e2@ngroups.net>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
Message-ID: <CAGGBd_o74zYyLnfa5vptZKK9_q7JrUY9O_2edPU5FUKWi88VLQ@mail.gmail.com>

On Mon, May 6, 2013 at 5:55 PM, duncan smith <buzzard at invalid.invalid>wrote:

>
> What license?
>>
>> Thanks!
>>
>>
> Here's the text I usually prepend.
>
>
> ##Copyright (c) 2013 duncan g. smith
> ##
> ##Permission is hereby granted, free of charge, to any person obtaining a
> ##copy of this software and associated documentation files (the
> "Software"),
> ##to deal in the Software without restriction, including without limitation
> ##the rights to use, copy, modify, merge, publish, distribute, sublicense,
> ##and/or sell copies of the Software, and to permit persons to whom the
> ##Software is furnished to do so, subject to the following conditions:
> ##
> ##The above copyright notice and this permission notice shall be included
> ##in all copies or substantial portions of the Software.
> ##
> ##THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
> ##OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> MERCHANTABILITY,
> ##FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> ##THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> ##OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> ##ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> ##OTHER DEALINGS IN THE SOFTWARE.
>
>
> Basically, "do what you want with it but don't blame me if it goes tits
> up". I'm happy to consider tidying it up a bit and using a more recognized
> form of licence. Just had a bank holiday here, so bug not yet squashed. But
> it is the sort of bug that might account for what you've seen (if a similar
> bug exists in the code you've been using). The tree doesn't always get
> properly rebalanced on node removals. I'll attack the problem later
> tomorrow (technically, later today). Cheers.
>

I'd prefer Apache or MIT or BSD 3-clause, but I could probably work with
this.
http://joinup.ec.europa.eu/community/eupl/news/licence-proliferation-way-out

I'm eager to see the code, and would love it if you sorted out the deletion
rebalance issue.

I just plunked some time into
https://github.com/headius/redblack/blob/master/red_black_tree.py , only to
find that it didn't appear to be doing deletions correctly - the tree would
become unprintable after deleting one element.  It's possible I introduced
the bug, but right now I don't particularly suspect so, having not changed
the __del__ method.

I'm starting to think Red Black Trees are pretty complex.
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From rosuav at gmail.com  Mon May  6 21:21:05 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 7 May 2013 11:21:05 +1000
Subject: Red Black Tree implementation?
In-Reply-To: <518850f8$0$8157$862e30e2@ngroups.net>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
Message-ID: <CAPTjJmoHgNH95C=nuqwSwOrko+egP5s1dpcSgfh_LgYddD6G1g@mail.gmail.com>

On Tue, May 7, 2013 at 10:55 AM, duncan smith <buzzard at invalid.invalid> wrote:
> Here's the text I usually prepend.
>
>
> ##Copyright (c) 2013 duncan g. smith
> ##
> ##Permission is hereby granted, free of charge, to any person obtaining a
> ##copy of this software and associated documentation files (the "Software"),
> ##to deal in the Software without restriction, including without limitation
> ##the rights to use, copy, modify, merge, publish, distribute, sublicense,
> ##and/or sell copies of the Software, and to permit persons to whom the
> ##Software is furnished to do so, subject to the following conditions:
> ##
> ##The above copyright notice and this permission notice shall be included
> ##in all copies or substantial portions of the Software.
> ##
> ##THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
> ##OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> MERCHANTABILITY,
> ##FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> ##THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> ##OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> ##ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> ##OTHER DEALINGS IN THE SOFTWARE.
>
>
> Basically, "do what you want with it but don't blame me if it goes tits up".
> I'm happy to consider tidying it up a bit and using a more recognized form
> of licence.

Is that the MIT license? If not, consider using it; it's well known
and trusted. I haven't eyeballed yours closely but it looks extremely
similar, at least.

ChrisA


From buzzard at invalid.invalid  Tue May  7 09:28:39 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Tue, 07 May 2013 14:28:39 +0100
Subject: Red Black Tree implementation?
In-Reply-To: <mailman.1393.1367889616.3114.python-list@python.org>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
Message-ID: <51890188$0$3095$862e30e2@ngroups.net>

On 07/05/13 02:20, Dan Stromberg wrote:
>
[snip]
>
> I'm starting to think Red Black Trees are pretty complex.
>
>

A while ago I looked at a few different types of self-balancing binary 
tree. Most look much easier to implement.

BTW, the licence might be MIT - I just copied it from someone else's code.

Duncan


From buzzard at invalid.invalid  Wed May  8 19:21:50 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Thu, 09 May 2013 00:21:50 +0100
Subject: Red Black Tree implementation?
In-Reply-To: <mailman.1393.1367889616.3114.python-list@python.org>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
Message-ID: <518ade0f$1$60230$862e30e2@ngroups.net>

On 07/05/13 02:20, Dan Stromberg wrote:
>
> On Mon, May 6, 2013 at 5:55 PM, duncan smith <buzzard at invalid.invalid
> <mailto:buzzard at invalid.invalid>> wrote:
>
>

[snip]

>
> I'd prefer Apache or MIT or BSD 3-clause, but I could probably work with
> this.
> http://joinup.ec.europa.eu/community/eupl/news/licence-proliferation-way-out
>
> I'm eager to see the code, and would love it if you sorted out the
> deletion rebalance issue.
>
> I just plunked some time into
> https://github.com/headius/redblack/blob/master/red_black_tree.py , only
> to find that it didn't appear to be doing deletions correctly - the tree
> would become unprintable after deleting one element.  It's possible I
> introduced the bug, but right now I don't particularly suspect so,
> having not changed the __del__ method.
>
> I'm starting to think Red Black Trees are pretty complex.
>
>

Mine is fixed now (sent to your gmail address). Restoring the tree 
properties after deletion is awkward to get right, and doesn't affect 
the performance noticeably for smallish trees if you get it wrong.

I realised my code was buggy when I tried adding, then removing a 
million items and ran into the recursion limit. It now passes a test 
where I check the tree properties after each addition / deletion.

Duncan


From drsalists at gmail.com  Wed May  8 21:40:06 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Wed, 8 May 2013 18:40:06 -0700
Subject: Red Black Tree implementation?
In-Reply-To: <518ade0f$1$60230$862e30e2@ngroups.net>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
	<518ade0f$1$60230$862e30e2@ngroups.net>
Message-ID: <CAGGBd_obTxft=Kh+WHUAjnig=Z+g07V4GrS7RcnLtc8gXeQb-w@mail.gmail.com>

OK, I've got one copy of trees.py with md5
211f80c0fe7fb9cb42feb9645b4b3ffe.  You seem to be saying I should have
two though, but I don't know that I do...


On 5/8/13, duncan smith <buzzard at invalid.invalid> wrote:
> On 07/05/13 02:20, Dan Stromberg wrote:
>>
>> On Mon, May 6, 2013 at 5:55 PM, duncan smith <buzzard at invalid.invalid
>> <mailto:buzzard at invalid.invalid>> wrote:
>>
>>
>
> [snip]
>
>>
>> I'd prefer Apache or MIT or BSD 3-clause, but I could probably work with
>> this.
>> http://joinup.ec.europa.eu/community/eupl/news/licence-proliferation-way-out
>>
>> I'm eager to see the code, and would love it if you sorted out the
>> deletion rebalance issue.
>>
>> I just plunked some time into
>> https://github.com/headius/redblack/blob/master/red_black_tree.py , only
>> to find that it didn't appear to be doing deletions correctly - the tree
>> would become unprintable after deleting one element.  It's possible I
>> introduced the bug, but right now I don't particularly suspect so,
>> having not changed the __del__ method.
>>
>> I'm starting to think Red Black Trees are pretty complex.
>>
>>
>
> Mine is fixed now (sent to your gmail address). Restoring the tree
> properties after deletion is awkward to get right, and doesn't affect
> the performance noticeably for smallish trees if you get it wrong.
>
> I realised my code was buggy when I tried adding, then removing a
> million items and ran into the recursion limit. It now passes a test
> where I check the tree properties after each addition / deletion.
>
> Duncan
> --
> http://mail.python.org/mailman/listinfo/python-list
>


From buzzard at invalid.invalid  Thu May  9 00:31:31 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Thu, 09 May 2013 05:31:31 +0100
Subject: Red Black Tree implementation?
In-Reply-To: <mailman.1473.1368063609.3114.python-list@python.org>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
	<518ade0f$1$60230$862e30e2@ngroups.net>
	<mailman.1473.1368063609.3114.python-list@python.org>
Message-ID: <518b26a4$0$4018$862e30e2@ngroups.net>

On 09/05/13 02:40, Dan Stromberg wrote:
> OK, I've got one copy of trees.py with md5
> 211f80c0fe7fb9cb42feb9645b4b3ffe.  You seem to be saying I should have
> two though, but I don't know that I do...
>
>

I've just re-sent it.

Duncan



From buzzard at invalid.invalid  Thu May  9 09:52:37 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Thu, 09 May 2013 14:52:37 +0100
Subject: Red Black Tree implementation?
In-Reply-To: <mailman.1473.1368063609.3114.python-list@python.org>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
	<518ade0f$1$60230$862e30e2@ngroups.net>
	<mailman.1473.1368063609.3114.python-list@python.org>
Message-ID: <518baa27$0$7930$862e30e2@ngroups.net>

On 09/05/13 02:40, Dan Stromberg wrote:
> OK, I've got one copy of trees.py with md5
> 211f80c0fe7fb9cb42feb9645b4b3ffe.  You seem to be saying I should have
> two though, but I don't know that I do...
>

[snip]

Yes, 211f80c0fe7fb9cb42feb9645b4b3ffe is the correct checksum for the 
latest version. The previous version had an issue when adding 
non-distinct items (items that compare equal to items already in the 
tree). Cheers.

Duncan



From drsalists at gmail.com  Sat May 11 19:24:42 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Sat, 11 May 2013 16:24:42 -0700
Subject: Red Black Tree implementation?
In-Reply-To: <518baa27$0$7930$862e30e2@ngroups.net>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
	<518ade0f$1$60230$862e30e2@ngroups.net>
	<mailman.1473.1368063609.3114.python-list@python.org>
	<518baa27$0$7930$862e30e2@ngroups.net>
Message-ID: <CAGGBd_r2k9qAM_xOsM4izecGZ=AVFH9jrrZ2nuhf4SGzqyDTZA@mail.gmail.com>

I'm afraid I'm having some trouble with the module.  I've checked it into
my SVN at http://stromberg.dnsalias.org/svn/red-black-tree-mod/trunk/duncan

I have two versions of your tests in there now - "t" is minimally changed,
and test-red_black_tree_mod is pretty restructured to facilitate adding
more tests later.  I get the same problem with either version of the tests.

The problem I'm seeing is that the tree, when built from items, isn't
looking quite right.  I inserted a print(tree) into the for loop, and I'm
getting the following, where I expected the tree to grow by one element on
each iteration:

$ python t
6 False None None
6 False 3 None
6 False 3 15
6 False 3 15
6 False 3 11
6 False 3 11
6 False 3 11
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15
11 False 6 15

Thoughts?

BTW, printing an empty tree seems to say "sentinel".  'not sure if that was
intended.

Thanks!



On Thu, May 9, 2013 at 6:52 AM, duncan smith <buzzard at invalid.invalid>wrote:

> On 09/05/13 02:40, Dan Stromberg wrote:
>
>> OK, I've got one copy of trees.py with md5
>> 211f80c0fe7fb9cb42feb9645b4b3f**fe.  You seem to be saying I should have
>> two though, but I don't know that I do...
>>
>>
> [snip]
>
> Yes, 211f80c0fe7fb9cb42feb9645b4b3f**fe is the correct checksum for the
> latest version. The previous version had an issue when adding non-distinct
> items (items that compare equal to items already in the tree). Cheers.
>
> Duncan
>
> --
> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>
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From drsalists at gmail.com  Sat May 11 21:29:23 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Sat, 11 May 2013 18:29:23 -0700
Subject: Red Black Tree implementation?
In-Reply-To: <CAGGBd_r2k9qAM_xOsM4izecGZ=AVFH9jrrZ2nuhf4SGzqyDTZA@mail.gmail.com>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
	<518ade0f$1$60230$862e30e2@ngroups.net>
	<mailman.1473.1368063609.3114.python-list@python.org>
	<518baa27$0$7930$862e30e2@ngroups.net>
	<CAGGBd_r2k9qAM_xOsM4izecGZ=AVFH9jrrZ2nuhf4SGzqyDTZA@mail.gmail.com>
Message-ID: <CAGGBd_o5JvkRAPzmCU0nBRz=o0iV=fLnfi_gsFR6+M6mUy0fFQ@mail.gmail.com>

On Sat, May 11, 2013 at 4:24 PM, Dan Stromberg <drsalists at gmail.com> wrote:

>
> I'm afraid I'm having some trouble with the module.  I've checked it into
> my SVN at
> http://stromberg.dnsalias.org/svn/red-black-tree-mod/trunk/duncan
>
> I have two versions of your tests in there now - "t" is minimally changed,
> and test-red_black_tree_mod is pretty restructured to facilitate adding
> more tests later.  I get the same problem with either version of the tests.
>
> The problem I'm seeing is that the tree, when built from items, isn't
> looking quite right.  I inserted a print(tree) into the for loop, and I'm
> getting the following, where I expected the tree to grow by one element on
> each iteration:
>
> $ python t
> 6 False None None
> 6 False 3 None
> 6 False 3 15
> 6 False 3 15
>
I figured out that this was printing a single node and some of its
attributes, not an entire tree.  I changed it to print an entire tree using
self.in_order().

I've also changed around the comparisons a bit, to use a __cmp__ method but
still provide __eq__, __neq__ and a new __lt__.

I'm up against a new problem now that it'd be nice if you could look at:
In BinaryTree.find(), it sometimes compares the item being searched for
against None.  In 2.x, this gives strange results, but may be benign in
this code.  In 3.x, this raises an exception.  I've added a comment about
this in the SVN repo I mentioned above.

You can see the traceback yourself with python3 test-red_black_tree_mod .

What should BinaryTree.find() do if it finds a data.node that is None?

Thanks!

PS: Is it about time we moved this discussion off python-list?
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From buzzard at invalid.invalid  Sat May 11 22:02:33 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Sun, 12 May 2013 03:02:33 +0100
Subject: Red Black Tree implementation?
In-Reply-To: <mailman.1574.1368322168.3114.python-list@python.org>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
	<518ade0f$1$60230$862e30e2@ngroups.net>
	<mailman.1473.1368063609.3114.python-list@python.org>
	<518baa27$0$7930$862e30e2@ngroups.net>
	<CAGGBd_r2k9qAM_xOsM4izecGZ=AVFH9jrrZ2nuhf4SGzqyDTZA@mail.gmail.com>
	<mailman.1574.1368322168.3114.python-list@python.org>
Message-ID: <518ef83b$0$24347$862e30e2@ngroups.net>

On 12/05/13 02:29, Dan Stromberg wrote:
>
> On Sat, May 11, 2013 at 4:24 PM, Dan Stromberg <drsalists at gmail.com
> <mailto:drsalists at gmail.com>> wrote:
>
>
>     I'm afraid I'm having some trouble with the module.  I've checked it
>     into my SVN at
>     http://stromberg.dnsalias.org/svn/red-black-tree-mod/trunk/duncan
>
>     I have two versions of your tests in there now - "t" is minimally
>     changed, and test-red_black_tree_mod is pretty restructured to
>     facilitate adding more tests later.  I get the same problem with
>     either version of the tests.
>
>     The problem I'm seeing is that the tree, when built from items,
>     isn't looking quite right.  I inserted a print(tree) into the for
>     loop, and I'm getting the following, where I expected the tree to
>     grow by one element on each iteration:
>
>     $ python t
>     6 False None None
>     6 False 3 None
>     6 False 3 15
>     6 False 3 15
>
> I figured out that this was printing a single node and some of its
> attributes, not an entire tree.  I changed it to print an entire tree
> using self.in_order().

Yes, I've just posted regarding that.

>
> I've also changed around the comparisons a bit, to use a __cmp__ method
> but still provide __eq__, __neq__ and a new __lt__.


I have implemented a lot (maybe all?) of the set methods in a subclass. 
I should probably root that out and have a think about what should be in 
the RedBlackTree class and what subclasses might look like.

>
> I'm up against a new problem now that it'd be nice if you could look at:
> In BinaryTree.find(), it sometimes compares the item being searched for
> against None.  In 2.x, this gives strange results, but may be benign in
> this code.  In 3.x, this raises an exception.  I've added a comment
> about this in the SVN repo I mentioned above.
>
> You can see the traceback yourself with python3 test-red_black_tree_mod .
>
> What should BinaryTree.find() do if it finds a data.node that is None?
>

A call to "find(data)" should find and return either a node containing 
"data"; or the sentinel node where "data" should be added. It should not 
get as far as the left or right child of a sentinel node (which would 
equal None). I'll look at this tomorrow. I did have the truth value of a 
node depending on it's data value (None implying False). Then I 
considered the possibility of actually wanting None as a value in the 
tree and changed it, so I could have introduced a bug here.

> Thanks!
>
> PS: Is it about time we moved this discussion off python-list?
>

Maybe. You have my official e-mail address. Cheers.

Duncan


From buzzard at invalid.invalid  Sun May 12 14:15:13 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Sun, 12 May 2013 19:15:13 +0100
Subject: Red Black Tree implementation?
In-Reply-To: <518ef83b$0$24347$862e30e2@ngroups.net>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
	<518ade0f$1$60230$862e30e2@ngroups.net>
	<mailman.1473.1368063609.3114.python-list@python.org>
	<518baa27$0$7930$862e30e2@ngroups.net>
	<CAGGBd_r2k9qAM_xOsM4izecGZ=AVFH9jrrZ2nuhf4SGzqyDTZA@mail.gmail.com>
	<mailman.1574.1368322168.3114.python-list@python.org>
	<518ef83b$0$24347$862e30e2@ngroups.net>
Message-ID: <518fdc34$0$18764$862e30e2@ngroups.net>

On 12/05/13 03:02, duncan smith wrote:
> On 12/05/13 02:29, Dan Stromberg wrote:
>>
>> On Sat, May 11, 2013 at 4:24 PM, Dan Stromberg <drsalists at gmail.com
>> <mailto:drsalists at gmail.com>> wrote:

[snip]

>>
>> What should BinaryTree.find() do if it finds a data.node that is None?
>>
>
> A call to "find(data)" should find and return either a node containing
> "data"; or the sentinel node where "data" should be added. It should not
> get as far as the left or right child of a sentinel node (which would
> equal None). I'll look at this tomorrow. I did have the truth value of a
> node depending on it's data value (None implying False). Then I
> considered the possibility of actually wanting None as a value in the
> tree and changed it, so I could have introduced a bug here.
>

It's a Python3 thing. The initial sentinel node was evaluating to True. 
__nonzero__ needs to be changed to __bool__.

>> Thanks!
>>
>> PS: Is it about time we moved this discussion off python-list?
>>

Let's do that from now.

Duncan



From buzzard at invalid.invalid  Sat May 11 21:34:32 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Sun, 12 May 2013 02:34:32 +0100
Subject: Red Black Tree implementation?
In-Reply-To: <mailman.1571.1368314691.3114.python-list@python.org>
References: <mailman.1225.1367449881.3114.python-list@python.org>
	<5181ca0e$0$13974$862e30e2@ngroups.net>
	<mailman.1260.1367546417.3114.python-list@python.org>
	<518850f8$0$8157$862e30e2@ngroups.net>
	<mailman.1393.1367889616.3114.python-list@python.org>
	<518ade0f$1$60230$862e30e2@ngroups.net>
	<mailman.1473.1368063609.3114.python-list@python.org>
	<518baa27$0$7930$862e30e2@ngroups.net>
	<mailman.1571.1368314691.3114.python-list@python.org>
Message-ID: <518ef1aa$0$33126$862e30e2@ngroups.net>

On 12/05/13 00:24, Dan Stromberg wrote:
>
> I'm afraid I'm having some trouble with the module.  I've checked it
> into my SVN at
> http://stromberg.dnsalias.org/svn/red-black-tree-mod/trunk/duncan
>
> I have two versions of your tests in there now - "t" is minimally
> changed, and test-red_black_tree_mod is pretty restructured to
> facilitate adding more tests later.  I get the same problem with either
> version of the tests.
>
> The problem I'm seeing is that the tree, when built from items, isn't
> looking quite right.  I inserted a print(tree) into the for loop, and
> I'm getting the following, where I expected the tree to grow by one
> element on each iteration:
>
> $ python t
> 6 False None None
> 6 False 3 None
> 6 False 3 15
> 6 False 3 15
> 6 False 3 11
> 6 False 3 11
> 6 False 3 11
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
> 11 False 6 15
>
> Thoughts?
>
> BTW, printing an empty tree seems to say "sentinel".  'not sure if that
> was intended.
>
> Thanks!
>

The leaf node has parent equal to None. All tree nodes have two 
children. One or both children may be sentinels, and a sentinel is 
signified by having both left and right (children) equal to None. So an 
empty tree is a sentinel node that is also root. So the string 
"sentinel" is expected (although possibly not the most sensible option).

For non-sentinel nodes the string is generated by,

return '%s %s %s' % (self.data, self.left.data, self.right.data)

for the BinaryTree class, and by

return '%s %s %s %s' % (self.data, self.is_red, self.left.data, 
self.right.data)

for the RedBlackTree class.


So what is being printed above is (in each case) the value contained in 
the root node, followed by its colour (True if red), and the values 
contained in the root node's left and right children.

The root node remains root, although it's value and its children (and 
their values) might change due to tree rotations.

It looks OK to me. The empty tree would print "sentinel". After adding 
the value 6 there is one tree node with sentinels as children (values 
equal to None). Adding 3 results in 3 being the value of the root's left 
child. It's right child is still a sentinel. Adding 15 results in that 
value being assigned to the right child. Adding 9 results in no change 
to the values in the root or its children. Adding 11 results in a tree 
rotation and 11 becomes the value in the right child of the root. At a 
later point a tree rotation results in the value of the root node being 
changed.

I haven't implemented a way of representing the structure of the whole 
red black tree. I would probably write some code to generate a dot file 
and use that to generate a png. But you could add something like,

print tree.height, tree.size, list(tree)

and get output like,

0 1 [6]
1 2 [3, 6]
1 3 [3, 6, 15]
2 4 [3, 6, 9, 15]
3 5 [3, 6, 9, 11, 15]
4 6 [3, 6, 9, 11, 12, 15]
4 7 [3, 6, 9, 11, 12, 15, 16]
5 8 [3, 6, 9, 11, 12, 14, 15, 16]
5 9 [3, 6, 9, 11, 12, 14, 15, 16, 17]
5 10 [3, 6, 7, 9, 11, 12, 14, 15, 16, 17]
5 11 [3, 6, 7, 9, 11, 12, 14, 15, 16, 17, 18]
5 12 [3, 5, 6, 7, 9, 11, 12, 14, 15, 16, 17, 18]
5 13 [3, 5, 6, 7, 8, 9, 11, 12, 14, 15, 16, 17, 18]
6 14 [3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18]
6 15 [0, 3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18]
6 16 [0, 2, 3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18]
6 17 [0, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18]
6 18 [-1, 0, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18]
6 19 [-1, 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]


It doesn't give you the structure, but it does show that it seems to be 
growing reasonably. Cheers.

Duncan




From christian at python.org  Thu May  2 06:46:47 2013
From: christian at python.org (Christian Heimes)
Date: Thu, 02 May 2013 12:46:47 +0200
Subject: Red Black Tree implementation?
In-Reply-To: <CAGGBd_rsM7LVd_V=Xb64vqeXmYCx2uxAnQfJo3MsHXJOphzJBQ@mail.gmail.com>
References: <CAGGBd_rsM7LVd_V=Xb64vqeXmYCx2uxAnQfJo3MsHXJOphzJBQ@mail.gmail.com>
Message-ID: <51824417.1@python.org>

Am 02.05.2013 01:11, schrieb Dan Stromberg:
> 
> What's the best Red Black Tree implementation for Python with an
> opensource license?
> 
> I started out looking at
> http://newcenturycomputers.net/projects/rbtree.html
> <http://newcenturycomputers.net/projects/rbtree..html> because it was
> pretty high in Google and had the operators I wanted, but it gets very
> slow at about half a million elements.  I've been discussing this with a
> C programmer who believes that Red Black Trees should perform very
> similarly to an AVL tree, but that's not at all what I'm getting with
> the newcenturycomputers implementation.

No wonder it's getting slow and doesn't stand a change against Python's
dict implementation. The rbtree implementation from
newcenturycomputers.net is written entirely in Python. It's good code
for academic research in order to study the properties of a rbtree.

If you need something production ready then you have to use an
implemetation with an optimized backend like a C code, PyPy or Cython.

Christian


From drsalists at gmail.com  Thu May  2 13:04:07 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Thu, 2 May 2013 10:04:07 -0700
Subject: Red Black Tree implementation?
In-Reply-To: <51824417.1@python.org>
References: <CAGGBd_rsM7LVd_V=Xb64vqeXmYCx2uxAnQfJo3MsHXJOphzJBQ@mail.gmail.com>
	<51824417.1@python.org>
Message-ID: <CAGGBd_r59TzsDQEaDzDsgvFs=YrXVk-DGmd-_cbUhS-=nAaSOw@mail.gmail.com>

On Thu, May 2, 2013 at 3:46 AM, Christian Heimes <christian at python.org>wrote:

> Am 02.05.2013 01:11, schrieb Dan Stromberg:



> No wonder it's getting slow and doesn't stand a change against Python's
> dict implementation. The rbtree implementation from
> newcenturycomputers.net is written entirely in Python. It's good code
> for academic research in order to study the properties of a rbtree.
>
> If you need something production ready then you have to use an
> implemetation with an optimized backend like a C code, PyPy or Cython.


The newcenturycomputers RBTree is similarly slow on CPython 2.x, CPython
3.x, PyPy and Jython.   I imagine the tree depth is getting deeper than it
should, but I've not verified that.  Also, the other datastructures I'm
comparing it to: B+ Tree, AVL Tree, Treap, etcetera are pure python too,
but they're performing reasonably - in fact, my expectations are pretty
much defined by these.

(OK, the treap code has a Cython version, but I'm not using that in this
project)

Thanks for the response.
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From contact_george at thiruva.com  Wed May  1 20:13:44 2013
From: contact_george at thiruva.com (George T)
Date: Wed, 1 May 2013 17:13:44 -0700 (PDT)
Subject: Failure to build Python 3.3.2 SSL Module
Message-ID: <9920f7c0-1c9d-4cb4-881f-e09e4cbed73f@googlegroups.com>

Anyone have any thoughts on building Python 3.3.2 with the SSL module? I'm on RedHat Enterprise 6.4 and used Yum to install the openssl and openssl-devel 1.0.1e packages. But I keep getting a failure to build the SSL module - even if I set CFLAGS and LDFLAGS to find the headers and libs or additionally install the 0.9.8e OpenSSL. Any thoughts on what the build scripts are looking for or failing on?

"""
gcc -pthread -shared -pg -L/usr/lib64 -L/usr/lib64/openssl/engines -L/usr/lib64/openssl098e/engines -L/usr/lib64 -L/usr/lib64/openssl/engines -L/usr/lib64/openssl098e/engines -L/usr/lib64 -L/usr/lib64/openssl/engines -L/usr/lib64/openssl098e/engines -I/usr/include build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/_ctypes.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/callbacks.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/callproc.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/stgdict.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/cfield.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/libffi/src/prep_cif.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/libffi/src/closures.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/libffi/src/dlmalloc.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/libffi/src/x86/ffi64.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/libffi/src/x86/unix64.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/libffi/src/x86/ffi.o build/temp.linux-x86_64-3.3/home/idcuser/ftp/Python-3.3.1/Modules/_ctypes/libffi/src/x86/sysv.o -L/usr/lib64 -L/usr/lib64/openssl/engines -L/usr/lib64/openssl098e/engines -L/usr/local/lib -o build/lib.linux-x86_64-3.3/_ctypes.cpython-33m.so

Failed to build these modules:
_ssl                                                  

running build_scripts
creating build/scripts-3.3
copying and adjusting /home/idcuser/ftp/Python-3.3.1/Tools/scripts/pydoc3 -> build/scripts-3.3
copying and adjusting /home/idcuser/ftp/Python-3.3.1/Tools/scripts/idle3 -> build/scripts-3.3
copying and adjusting /home/idcuser/ftp/Python-3.3.1/Tools/scripts/2to3 -> build/scripts-3.3
copying and adjusting /home/idcuser/ftp/Python-3.3.1/Tools/scripts/pyvenv -> build/scripts-3.3
changing mode of build/scripts-3.3/pydoc3 from 664 to 775
changing mode of build/scripts-3.3/idle3 from 664 to 775
changing mode of build/scripts-3.3/2to3 from 664 to 775
changing mode of build/scripts-3.3/pyvenv from 664 to 775
renaming build/scripts-3.3/pydoc3 to build/scripts-3.3/pydoc3.3
renaming build/scripts-3.3/idle3 to build/scripts-3.3/idle3.3
renaming build/scripts-3.3/2to3 to build/scripts-3.3/2to3-3.3
renaming build/scripts-3.3/pyvenv to build/scripts-3.3/pyvenv-3.3

real	1m20.759s
user	2m6.167s
sys	0m8.557s
"""

Thanks in advance!

Cheers,

George


From holdenweb at gmail.com  Thu May  2 00:16:16 2013
From: holdenweb at gmail.com (holdenweb at gmail.com)
Date: Wed, 1 May 2013 21:16:16 -0700 (PDT)
Subject: how to get next month string?
In-Reply-To: <1185278216.225757.195290@d55g2000hsg.googlegroups.com>
References: <f84kee$q32$1@wake.carmen.se>
	<1185278216.225757.195290@d55g2000hsg.googlegroups.com>
Message-ID: <acbd110a-bdd5-4c04-9200-2700de0edcb0@googlegroups.com>

Hello. Is that you? Wondered what you had been up to lately and discovered that your email address hadn't transferred across to my new computer, so I had to resort to Google and found you on camp.lang.python - I hope!

regards
 Steve

On Tuesday, July 24, 2007 4:56:56 AM UTC-7, BartlebyScrivener wrote:
> On Jul 24, 5:31 am, "Yinghe Chen" <yinghe.c... at jeppesen.com> wrote:
> > Hi,
> > Could someone help on how to use python to output the next month string like
> > this?
> >
> > "AUG07", suppose now is July 2007.
> >
> 
> I usually find time and date answers somewhere in here:
> 
> http://pleac.sourceforge.net/pleac_python/datesandtimes.html
> 
> rd



From anadionisio257 at gmail.com  Thu May  2 05:10:11 2013
From: anadionisio257 at gmail.com (=?ISO-8859-1?Q?Ana_Dion=EDsio?=)
Date: Thu, 2 May 2013 02:10:11 -0700 (PDT)
Subject: Sum operation in numpy arrays
Message-ID: <756832e9-4579-498e-b55c-f1a98f42a113@googlegroups.com>

Hello! I have several numpy arrays in my script and i want to add them. For example:

a=[1,2,3,4,5]
b=[1,1,1,1,1]
c=[1,0,1,0,1]

for i in range(5):
    d[i]=a[i]+b[i]+c[i]

print d

[3,3,5,5,7]

I did it like that but I get an error: "TypeError: unsupported operand type(s) for +: 'float' and 'numpy.string_'"

How can I sum my arrays?


From jt at toerring.de  Thu May  2 06:24:13 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 2 May 2013 10:24:13 GMT
Subject: Sum operation in numpy arrays
References: <756832e9-4579-498e-b55c-f1a98f42a113@googlegroups.com>
Message-ID: <auet6dFmjutU1@mid.uni-berlin.de>

Ana Dion?sio <anadionisio257 at gmail.com> wrote:
> Hello! I have several numpy arrays in my script and i want to add them. For example:

> a=[1,2,3,4,5]
> b=[1,1,1,1,1]
> c=[1,0,1,0,1]

> for i in range(5):
>     d[i]=a[i]+b[i]+c[i]

> print d

> [3,3,5,5,7]

> I did it like that but I get an error: "TypeError: unsupported operand type(s) for +: 'float' and 'numpy.string_'"

> How can I sum my arrays?

There's no numpy array at all in use in your example program, you
only have normal lists. If you had numpy arrays you wouldn't need
to loop over the indivindual elements, you could do just

d = a + b + c

to add up the (numpy) arrays.

The error message you get may indicate that somewhere in your real
code (not the one you posted) one of the elements of one of the
(numpy) arrays is not a number but a string, e.g. by doing some-
thing like

a = numpy.array( [ 1, '2', 3, 4, 5 ] )

(note the single quotes around 2, that will result in the element
having a type of 'numpy.string'. But if it's like that is impossible
to tell without seeing the real code you're using;-) I guess you
will have to give us what you actually use if you want something
more helpful.
                            Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From steve+comp.lang.python at pearwood.info  Thu May  2 06:33:57 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 02 May 2013 10:33:57 GMT
Subject: Sum operation in numpy arrays
References: <756832e9-4579-498e-b55c-f1a98f42a113@googlegroups.com>
Message-ID: <51824115$0$29969$c3e8da3$5496439d@news.astraweb.com>

On Thu, 02 May 2013 02:10:11 -0700, Ana Dion?sio wrote:

> Hello! I have several numpy arrays in my script and i want to add them.
> For example:
> 
> a=[1,2,3,4,5]
> b=[1,1,1,1,1]
> c=[1,0,1,0,1]

These are not numpy arrays, they are lists of ints. Based on the error 
message you quote:

TypeError: unsupported operand type(s) for +: 'float' and 'numpy.string_'"

you have at least one numpy array of floats, and one numpy array of 
strings. Identify which array has got strings in it instead of floats, 
then identify how it got filled with strings, and change it to fill it 
with floats instead.

Start by printing this:

print(type(a), type(b), type(c))
print(type(a[0]), type(b[0]), type(c[0]))

and see what they say. 


My guess is that somewhere in your code you have a list of strings:

l = ['1', '2', '3']

(perhaps because you read them from a file), and then you converted it to 
a numpy array:

x = numpy.array(l)


without converting the strings to floats.


-- 
Steven


From l.selmi at icloud.com  Thu May  2 09:56:28 2013
From: l.selmi at icloud.com (leonardo selmi)
Date: Thu, 02 May 2013 15:56:28 +0200
Subject: help..
Message-ID: <57E38A20-B52B-4CAE-B1FB-487DD99B48AD@icloud.com>

i have also this program:

write a function called rental_car_costthat takes days as input and returns the cost for renting a car for said number of days. The cost must abide by the following conditions:
Every day you rent the car is $40.
If you rent the car for 3 or more days, you get $20 off your total.
If you rent the car for 7 or more days, you get $50 off your total. (This does not stack with the 20 dollars you get for renting the car over 3 days.)
so i wrote the following code:
def rental_car_cost(days):
        cost = 40*days
        if days >= 7:
            return cost - 50
        elif days >= 3 and days < 7:
            return cost - 20
        else:
            return cost

but it seems not to be right cause the computer answers: Oops, try again! Did you create a function called rental_car_cost?

ii wrote also:

def rental_car_cost(days):
    if days >= 7:
        return (40*days) - 50
    if days >= 3 and < 7:
        return (40*days) - 20
    else:
        return (40*days)

they both work in python shell/idle but not in the exercise in "codecademy"..what do you think? is there a bug?

thanks!

kindest regards
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From rosuav at gmail.com  Thu May  2 10:06:11 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 3 May 2013 00:06:11 +1000
Subject: help..
In-Reply-To: <57E38A20-B52B-4CAE-B1FB-487DD99B48AD@icloud.com>
References: <57E38A20-B52B-4CAE-B1FB-487DD99B48AD@icloud.com>
Message-ID: <CAPTjJmpP_xrF1Th--H-zrYEuvWzFKOzZVCxeRx5qUY_FRM4R4w@mail.gmail.com>

On Thu, May 2, 2013 at 11:56 PM, leonardo selmi <l.selmi at icloud.com> wrote:
> so i wrote the following code:
> def rental_car_cost(days):
>         cost = 40*days
>         if days >= 7:
>             return cost - 50
>         elif days >= 3 and days < 7:
>             return cost - 20
>         else:
>             return cost
>
> but it seems not to be right cause the computer answers: Oops, try again!
> Did you create a function called rental_car_cost?

That code looks fine to me (though I'd drop the "and days < 7" as it's
redundant); but the error you're getting isn't a Python exception.
What's giving that error? You may need to check the framing of your
code. How does codecademy (which I'm not familiar with) locate your
function?

ChrisA


From tampucciolina at libero.it  Thu May  2 10:20:48 2013
From: tampucciolina at libero.it (leonardo)
Date: Thu, 2 May 2013 16:20:48 +0200
Subject: help..
In-Reply-To: <CAPTjJmpP_xrF1Th--H-zrYEuvWzFKOzZVCxeRx5qUY_FRM4R4w@mail.gmail.com>
References: <57E38A20-B52B-4CAE-B1FB-487DD99B48AD@icloud.com>
	<CAPTjJmpP_xrF1Th--H-zrYEuvWzFKOzZVCxeRx5qUY_FRM4R4w@mail.gmail.com>
Message-ID: <F8F6FCFD-1BB9-42D8-80DC-0631F7B34DD3@libero.it>

on codecademy there is an interactive box where you type your code, it is a kind of exercise program to practice. but i don't understand what is wrong. this is the website address of that if you want to give a look:

http://www.codecademy.com/courses/python-beginner-P5YtY/1/3?curriculum_id=4f89dab3d788890003000096




Il giorno 02/mag/2013, alle ore 16:06, Chris Angelico <rosuav at gmail.com> ha scritto:

> On Thu, May 2, 2013 at 11:56 PM, leonardo selmi <l.selmi at icloud.com> wrote:
>> so i wrote the following code:
>> def rental_car_cost(days):
>>        cost = 40*days
>>        if days >= 7:
>>            return cost - 50
>>        elif days >= 3 and days < 7:
>>            return cost - 20
>>        else:
>>            return cost
>> 
>> but it seems not to be right cause the computer answers: Oops, try again!
>> Did you create a function called rental_car_cost?
> 
> That code looks fine to me (though I'd drop the "and days < 7" as it's
> redundant); but the error you're getting isn't a Python exception.
> What's giving that error? You may need to check the framing of your
> code. How does codecademy (which I'm not familiar with) locate your
> function?
> 
> ChrisA
> -- 
> http://mail.python.org/mailman/listinfo/python-list



From rosuav at gmail.com  Thu May  2 10:30:02 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 3 May 2013 00:30:02 +1000
Subject: help..
In-Reply-To: <F8F6FCFD-1BB9-42D8-80DC-0631F7B34DD3@libero.it>
References: <57E38A20-B52B-4CAE-B1FB-487DD99B48AD@icloud.com>
	<CAPTjJmpP_xrF1Th--H-zrYEuvWzFKOzZVCxeRx5qUY_FRM4R4w@mail.gmail.com>
	<F8F6FCFD-1BB9-42D8-80DC-0631F7B34DD3@libero.it>
Message-ID: <CAPTjJmp4Sseb1v74DKBES5i=pm0_cAPmQnNKeiFbnODFdsYWxw@mail.gmail.com>

On Fri, May 3, 2013 at 12:20 AM, leonardo <tampucciolina at libero.it> wrote:
> on codecademy there is an interactive box where you type your code, it is a kind of exercise program to practice. but i don't understand what is wrong. this is the website address of that if you want to give a look:
>
> http://www.codecademy.com/courses/python-beginner-P5YtY/1/3?curriculum_id=4f89dab3d788890003000096

Well, I gave it a try, and it seemed to work :) Your second example
has a syntactic error (probably you want to say "days" again in the
second half of the 'and' condition), but with that fixed, both work
and are accepted by the opposite end. Though that last consideration
may not be all that indicative; this code was accepted and gave the
"Way to go!" success message:

def rental_car_cost(days):
    raise OSError()

Yeah, I don't think that quite worked :)

ChrisA


From robert.kern at gmail.com  Thu May  2 10:30:36 2013
From: robert.kern at gmail.com (Robert Kern)
Date: Thu, 02 May 2013 15:30:36 +0100
Subject: help..
In-Reply-To: <F8F6FCFD-1BB9-42D8-80DC-0631F7B34DD3@libero.it>
References: <57E38A20-B52B-4CAE-B1FB-487DD99B48AD@icloud.com>
	<CAPTjJmpP_xrF1Th--H-zrYEuvWzFKOzZVCxeRx5qUY_FRM4R4w@mail.gmail.com>
	<F8F6FCFD-1BB9-42D8-80DC-0631F7B34DD3@libero.it>
Message-ID: <kltta7$p0o$1@ger.gmane.org>

On 2013-05-02 15:20, leonardo wrote:
> on codecademy there is an interactive box where you type your code, it is a kind of exercise program to practice. but i don't understand what is wrong. this is the website address of that if you want to give a look:
>
> http://www.codecademy.com/courses/python-beginner-P5YtY/1/3?curriculum_id=4f89dab3d788890003000096

I think the problem is in the codecademy interface (or your use of it) rather 
than the Python code. You will probably get better help in the codecademy forums 
or help documentation:

   http://www.codecademy.com/forums/python-beginner-P5YtY/1
   http://help.codecademy.com/

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco



From hermanmu at gmail.com  Thu May  2 10:56:33 2013
From: hermanmu at gmail.com (Michael Herman)
Date: Thu, 2 May 2013 07:56:33 -0700
Subject: help..
In-Reply-To: <kltta7$p0o$1@ger.gmane.org>
References: <57E38A20-B52B-4CAE-B1FB-487DD99B48AD@icloud.com>
	<CAPTjJmpP_xrF1Th--H-zrYEuvWzFKOzZVCxeRx5qUY_FRM4R4w@mail.gmail.com>
	<F8F6FCFD-1BB9-42D8-80DC-0631F7B34DD3@libero.it>
	<kltta7$p0o$1@ger.gmane.org>
Message-ID: <CA+f8p+zufj_6h_rctMSKCzx9EsjtmntSjsVSegU-vYBwYzzLQA@mail.gmail.com>

the problem is in your code: http://screencast.com/t/haF1NY5RvpMv



On Thu, May 2, 2013 at 7:30 AM, Robert Kern <robert.kern at gmail.com> wrote:
>
> On 2013-05-02 15:20, leonardo wrote:
>>
>> on codecademy there is an interactive box where you type your code, it is a kind of exercise program to practice. but i don't understand what is wrong. this is the website address of that if you want to give a look:
>>
>> http://www.codecademy.com/courses/python-beginner-P5YtY/1/3?curriculum_id=4f89dab3d788890003000096
>
>
> I think the problem is in the codecademy interface (or your use of it) rather than the Python code. You will probably get better help in the codecademy forums or help documentation:
>
>   http://www.codecademy.com/forums/python-beginner-P5YtY/1
>   http://help.codecademy.com/
>
> --
> Robert Kern
>
> "I have come to believe that the whole world is an enigma, a harmless enigma
>  that is made terrible by our own mad attempt to interpret it as though it had
>  an underlying truth."
>   -- Umberto Eco
>
> --
> http://mail.python.org/mailman/listinfo/python-list


From tampucciolina at libero.it  Thu May  2 10:43:05 2013
From: tampucciolina at libero.it (leonardo)
Date: Thu, 2 May 2013 16:43:05 +0200
Subject: help..
In-Reply-To: <kltta7$p0o$1@ger.gmane.org>
References: <57E38A20-B52B-4CAE-B1FB-487DD99B48AD@icloud.com>
	<CAPTjJmpP_xrF1Th--H-zrYEuvWzFKOzZVCxeRx5qUY_FRM4R4w@mail.gmail.com>
	<F8F6FCFD-1BB9-42D8-80DC-0631F7B34DD3@libero.it>
	<kltta7$p0o$1@ger.gmane.org>
Message-ID: <18E5788F-3B66-4652-A101-EBAE7D4F63E2@libero.it>

thanks at all


Il giorno 02/mag/2013, alle ore 16:30, Robert Kern <robert.kern at gmail.com> ha scritto:

> On 2013-05-02 15:20, leonardo wrote:
>> on codecademy there is an interactive box where you type your code, it is a kind of exercise program to practice. but i don't understand what is wrong. this is the website address of that if you want to give a look:
>> 
>> http://www.codecademy.com/courses/python-beginner-P5YtY/1/3?curriculum_id=4f89dab3d788890003000096
> 
> I think the problem is in the codecademy interface (or your use of it) rather than the Python code. You will probably get better help in the codecademy forums or help documentation:
> 
>  http://www.codecademy.com/forums/python-beginner-P5YtY/1
>  http://help.codecademy.com/
> 
> -- 
> Robert Kern
> 
> "I have come to believe that the whole world is an enigma, a harmless enigma
> that is made terrible by our own mad attempt to interpret it as though it had
> an underlying truth."
>  -- Umberto Eco
> 
> -- 
> http://mail.python.org/mailman/listinfo/python-list



From rosuav at gmail.com  Thu May  2 10:36:48 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 3 May 2013 00:36:48 +1000
Subject: Python teaching book recommendations: 3.3+ and with exercises
Message-ID: <CAPTjJmoJ8cC0wvv04gnJc77X-3uztvaX27Q_Y7oWbtJZYpRh6w@mail.gmail.com>

One of my younger brothers, still school age, is to be studying some
aspect of computing for the next term or two. I strongly recommended
he learn Python (it has a bit more future than studying the internals
of OS/2), and my/his father then asked me what book I'd recommend him
to study through. I know this has come up a few times, but searching
back in my emails didn't give a clear answer.

Whether it's an ebook or in paper doesn't matter, but there need to be
exercises that the student can perform on his own, and then an
external tutor (aka my dad) then check up on. Python 3 is a must;
preferably something designed for 3.3+ as that's what he'll be using.
Beyond that, I was just asked to recommend "the best", which is
unfortunately vague... but I gather they'll be deferring to the
expertise of the list in figuring out what that means :)

So, within those not-very-many restrictions, what would you all
recommend? Let's get a nice discussion going and see where it leads us
(most likely to a resident troll ranting about a favorite topic, but
hey, maybe Dihedral will come out with some nugget of wisdom for us)!

Chris Angelico


From wingusr at gmail.com  Thu May  2 21:06:03 2013
From: wingusr at gmail.com (TP)
Date: Thu, 2 May 2013 18:06:03 -0700
Subject: Python teaching book recommendations: 3.3+ and with exercises
In-Reply-To: <CAPTjJmoJ8cC0wvv04gnJc77X-3uztvaX27Q_Y7oWbtJZYpRh6w@mail.gmail.com>
References: <CAPTjJmoJ8cC0wvv04gnJc77X-3uztvaX27Q_Y7oWbtJZYpRh6w@mail.gmail.com>
Message-ID: <CAMEax75-cN1844JRiMB4V69Lcai=Yz6dTqL-xJ+ZK5ii7af6ww@mail.gmail.com>

On Thu, May 2, 2013 at 7:36 AM, Chris Angelico <rosuav at gmail.com> wrote:

> One of my younger brothers, still school age, is to be studying some
> aspect of computing for the next term or two. I strongly recommended
> he learn Python (it has a bit more future than studying the internals
> of OS/2), and my/his father then asked me what book I'd recommend him
> to study through. I know this has come up a few times, but searching
> back in my emails didn't give a clear answer.
>
> Whether it's an ebook or in paper doesn't matter, but there need to be
> exercises that the student can perform on his own, and then an
> external tutor (aka my dad) then check up on. Python 3 is a must;
> preferably something designed for 3.3+ as that's what he'll be using.
> Beyond that, I was just asked to recommend "the best", which is
> unfortunately vague... but I gather they'll be deferring to the
> expertise of the list in figuring out what that means :)
>
> So, within those not-very-many restrictions, what would you all
> recommend? Let's get a nice discussion going and see where it leads us
> (most likely to a resident troll ranting about a favorite topic, but
> hey, maybe Dihedral will come out with some nugget of wisdom for us)!
>

Since I've been using Python for years, I've only skimmed new books.
Personally, I found the standard Python tutorial [1] (and reading the
What's New sections) more than adequate for originally learning Python.

Anyway, given your constraints, here's what I've come up with (stipulating
Python 3, limits the number of available books. And requiring exercises is
even stricter):

Python for Kids - A Playful Introduction to Programming - J. Briggs (No
Starch, 2013) [2]. Python 3.2? Not necessarily just for kids but definitely
slanted towards younger readers. Has "Programming Puzzles".

Think Python - A. Downey (O'Reilly, 2012) [3]. For Python 2 & 3. Exercises
but no answers? There is also a Python 3 specific version available. Free.

Beginning Python - Using Python 2.6 and Python 3.1 - J. Payne (Wrox, 2010)
[4]. Has exercises but... they seem a bit simplistic to me. Answers in
Appendix A.

Head First Python - Barry (OReilly,2011) [5] Python 3. Says for people who
already know another language (and I would have to agree with that).
Exercises.

Introduction to Programming Using Python - Y. Liang (Pearson, 2013) [6]. A
bit dull looking. Probably a college textbook? Lots of exercises. Author
also has similar books on C++ & Java. Expensive.

Ignoring the constraints, here's another one that looks really interesting:

Hello Python - A. Briggs (Manning, 2012) [7]. Python 2 only. Learn by
incrementally writing and improving working programs. Less focused on
syntax and more on getting the job done. No exercises per se, but since
goal is working programs, progress can be still be checked. More about the
"batteries" (including somewhat surprisingly pyglet, twisted & django).

    From the Preface:

    "I thought back to how I first learned to program. I didn't read an
    entire programming book from cover to cover and then write a program
    after I knew everything there was to know. Instead I started with a
    goal, something that I wanted to do, and worked toward it, figuring
    things out as I went. I read programming books from time to time,
    but really only to figure out the bits I was stuck on. When I was
    done, my programs weren't particularly elegant or fast, but they
    were mine---I knew how they worked, and they solved a real problem
    that I was having."

    Page 9:

    "We'll be using the latest version of Python 2, because most of the
    libraries that we'll use in this book don?t yet support Python 3."

[1] http://docs.python.org/3/tutorial/index.html

[2] http://nostarch.com/pythonforkids

[3] http://www.greenteapress.com/thinkpython/thinkpython.html

[4]
http://www.wrox.com/WileyCDA/WroxTitle/Beginning-Python-Using-Python-2-6-and-Python-3-1.productCd-0470414634.html

[5] http://shop.oreilly.com/product/0636920003434.do

[6]
http://www.pearsonhighered.com/educator/product/Introduction-to-Programming-Using-Python/9780132747189.page

[7] http://www.manning.com/briggs/
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From rosuav at gmail.com  Fri May  3 05:04:43 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 3 May 2013 19:04:43 +1000
Subject: Python teaching book recommendations: 3.3+ and with exercises
In-Reply-To: <CAMEax75-cN1844JRiMB4V69Lcai=Yz6dTqL-xJ+ZK5ii7af6ww@mail.gmail.com>
References: <CAPTjJmoJ8cC0wvv04gnJc77X-3uztvaX27Q_Y7oWbtJZYpRh6w@mail.gmail.com>
	<CAMEax75-cN1844JRiMB4V69Lcai=Yz6dTqL-xJ+ZK5ii7af6ww@mail.gmail.com>
Message-ID: <CAPTjJmo4Uims8U-j2StUcX-KC9t5XuXb82WE0rkyqcezYTOK4w@mail.gmail.com>

On Fri, May 3, 2013 at 11:06 AM, TP <wingusr at gmail.com> wrote:
> Since I've been using Python for years, I've only skimmed new books. Personally, I found the standard Python tutorial [1] (and reading the What's New sections) more than adequate for originally learning Python.
>
> Anyway, given your constraints, here's what I've come up with (stipulating Python 3, limits the number of available books. And requiring exercises is even stricter):

Thanks for the tips, TP! I'll discuss these with the appropriate
people over the weekend. From first glance, this is how they seem to
me:

> Python for Kids - A Playful Introduction to Programming - J. Briggs (No Starch, 2013) [2]. Python 3.2? Not necessarily just for kids but definitely slanted towards younger readers. Has "Programming Puzzles".

Might skip this one. He's already tinkering with his own Linux box, so
I don't think we need to go childish.

> Think Python - A. Downey (O'Reilly, 2012) [3]. For Python 2 & 3. Exercises but no answers? There is also a Python 3 specific version available. Free.

That looks good. Lack of answers isn't a problem; if Dad can't figure
it out, he can always ask me. (But I'm hoping to be involved as little
as possible with the detaily bits.)

> Beginning Python - Using Python 2.6 and Python 3.1 - J. Payne (Wrox, 2010) [4]. Has exercises but... they seem a bit simplistic to me. Answers in Appendix A.

Perhaps, but I'll keep it on the list anyway.

> Head First Python - Barry (OReilly,2011) [5] Python 3. Says for people who already know another language (and I would have to agree with that). Exercises.

Pass on that, then; Python's his first real language study.

> Introduction to Programming Using Python - Y. Liang (Pearson, 2013) [6]. A bit dull looking. Probably a college textbook? Lots of exercises. Author also has similar books on C++ & Java. Expensive.

I'll mention it, but expensive is a downside when there are a number
of free and/or cheap options!

> Ignoring the constraints, here's another one that looks really interesting:
>
> Hello Python - A. Briggs (Manning, 2012) [7]. Python 2 only. Learn by incrementally writing and improving working programs. Less focused on syntax and more on getting the job done. No exercises per se, but since goal is working programs, progress can be still be checked. More about the "batteries" (including somewhat surprisingly pyglet, twisted & django).
>
>     "We'll be using the latest version of Python 2, because most of the
>     libraries that we'll use in this book don?t yet support Python 3."

I'll avoid that, then; I really don't want to have to get into a
discussion of raw_input() vs input() after he's befuddled himself, nor
do I intend to re-argue Unicode vs bytes!

Many thanks for the suggestions. Was kinda hoping for multiple
people's chimings-in; I know there'll be some strong opinions around
the list... it's what we do best... :)

ChrisA


From alister.ware at ntlworld.com  Fri May  3 06:49:03 2013
From: alister.ware at ntlworld.com (Alister)
Date: Fri, 03 May 2013 10:49:03 GMT
Subject: Python teaching book recommendations: 3.3+ and with exercises
References: <mailman.1244.1367505416.3114.python-list@python.org>
Message-ID: <zCMgt.166784$5w6.61833@fx05.fr7>

On Fri, 03 May 2013 00:36:48 +1000, Chris Angelico wrote:

> One of my younger brothers, still school age, is to be studying some
> aspect of computing for the next term or two. I strongly recommended he
> learn Python (it has a bit more future than studying the internals of
> OS/2), and my/his father then asked me what book I'd recommend him to
> study through. I know this has come up a few times, but searching back
> in my emails didn't give a clear answer.
> 
> Whether it's an ebook or in paper doesn't matter, but there need to be
> exercises that the student can perform on his own, and then an external
> tutor (aka my dad) then check up on. Python 3 is a must; preferably
> something designed for 3.3+ as that's what he'll be using. Beyond that,
> I was just asked to recommend "the best", which is unfortunately
> vague... but I gather they'll be deferring to the expertise of the list
> in figuring out what that means :)
> 
> So, within those not-very-many restrictions, what would you all
> recommend? Let's get a nice discussion going and see where it leads us
> (most likely to a resident troll ranting about a favorite topic, but
> hey, maybe Dihedral will come out with some nugget of wisdom for us)!
> 
> Chris Angelico

A guy of your abilities & knowledge, why not write your own. you could 
use the experience of teaching your brother to hone it to perfection.

Ok this was slightly tounge in cheek ( but not intended to be in any way 
offensive).  I will now offer to put my money where my mouth is an make a 
contribution if you were to put it up on kickstarter.



-- 
"Cogito ergo I'm right and you're wrong."
-- Blair Houghton


From rosuav at gmail.com  Fri May  3 07:09:42 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 3 May 2013 21:09:42 +1000
Subject: Python teaching book recommendations: 3.3+ and with exercises
In-Reply-To: <zCMgt.166784$5w6.61833@fx05.fr7>
References: <mailman.1244.1367505416.3114.python-list@python.org>
	<zCMgt.166784$5w6.61833@fx05.fr7>
Message-ID: <CAPTjJmoxHENF7wBjnih=6_w9J_ca=SzEo0V70y4g8dvdq42QhQ@mail.gmail.com>

On Fri, May 3, 2013 at 8:49 PM, Alister <alister.ware at ntlworld.com> wrote:
> A guy of your abilities & knowledge, why not write your own. you could
> use the experience of teaching your brother to hone it to perfection.
>
> Ok this was slightly tounge in cheek ( but not intended to be in any way
> offensive).  I will now offer to put my money where my mouth is an make a
> contribution if you were to put it up on kickstarter.

Not at all offensive... it just implies that I have time to spend,
during the day, somewhere in between holding down my own full-time job
:) I'm hoping to be involved as little as possible in the day-to-day
of it, though of course I'll be as happy to answer his questions as I
am to answer them here on the list. Also, the suggestion implies that
I'm a Python expert, which isn't exactly true; I actually have not
done many nontrivial Python programs (for instance, I've never used
_any_ of the GUI toolkits available). Hence my hope of finding a book
written by an expert and recommended by experts. :)

ChrisA


From wingusr at gmail.com  Fri May  3 10:54:53 2013
From: wingusr at gmail.com (TP)
Date: Fri, 3 May 2013 07:54:53 -0700
Subject: Python teaching book recommendations: 3.3+ and with exercises
In-Reply-To: <CAPTjJmoxHENF7wBjnih=6_w9J_ca=SzEo0V70y4g8dvdq42QhQ@mail.gmail.com>
References: <mailman.1244.1367505416.3114.python-list@python.org>
	<zCMgt.166784$5w6.61833@fx05.fr7>
	<CAPTjJmoxHENF7wBjnih=6_w9J_ca=SzEo0V70y4g8dvdq42QhQ@mail.gmail.com>
Message-ID: <CAMEax75KY2xKTsJ2yCYJw8A5kg6hVwFB2TgH+bpFfuVnu913KA@mail.gmail.com>

[Just a note, all the book links in my original post have complete table of
contents listing, so don't just take my word on their suitability.]

Here's some
I missed:

Programming in Python 3, 2nd Edition - Mark Summerfield (Addison-Wesley,
2009) [1a]. Exercises. Solutions available online. At a quick glance I'd
say the exercises are also better for the beginner. Less of a computer
science orientation?

Learning Python, 4th Edition, Mark Lutz (Oreilly,2009) [1]. The 5th edition
[2] is supposed to come out in June. Python 2.6 & 3.x. Has exercises at the
end of every Part and answers in Appendix B. Also has "Test Your Knowledge"
quizzes & answers. 1200+ pages! Too overwhelming for a first Python book?
Ideal for a 2nd or 3rd however.

After seeing your response, I'd say, just one book isn't really going to
work. So I would recommend:

1) Quickly go through Python for Kids. While it may say it's for kids, it
actually covers quite a bit of ground (including writing a game using
tkinter). I doubt it's so easy as to be boring. The lazy can also download
sample code and solutions to the Programming Puzzles from the webpage.

2) Then Summerfield's Programming in Python 3. It has a lot more detail and
also
spends time on the Python Standard Library.

Or maybe Think Python. A *lot* drier presentation than Python for Kids --
after all, the subtitle which I forgot to mention is "How to Think Like a
Computer Scientist". Newer than Summerfield
, but only 1/3 the length
. Since I've only skimmed both I find it hard to recommend one over the
other.

3) Finally, when he *really* wants to learn all the gory details about
Python programming, tackle Learning Python (and by that time hopefully the
5th edition will be out).

Once you've "learned"
P
ython then I would also recommend Programming Python, 4e - Mark Lutz
(Oreilly,2010) [3] for detailed info on using some of the standard modules.
Also Python Cookbook: Recipes for Mastering Python 3 - Beazley & Jone
(OReilly, 2013) [4].

[Off Topic] --------

Depending on his age and what else he is learning at school, I also kinda
think NumPy/SciPy/Matplotlib can be very enlightening.

SciPy and NumPy - E. Bressert (O'Reilly, 2013) [5]. A brief overview.

NumPy 1.5 Beginner's Guide - I. Idris (Packt, 2011) [6]

NumPy Cookbook - I. Idris (Packt, 2012) [7]

Already started back in February and ending in a month, there is MIT's free
online
video
edX course "6.00x: Introduction to Computer Science and Programming" [8]
which uses Python 2.7 and the book "Introduction to Computation and
Programming Using Python (Spring 2013 edition)" by John Guttag [9]. This is
also viewable free online if you are registered for the course. Estimated
effort 12 hours/week, eeek!


[1a] http://www.qtrac.eu/py3book.html

[1] http://shop.oreilly.com/product/9780596158071.do

[2] http://shop.oreilly.com/product/0636920028154.do

[3] http://shop.oreilly.com/product/9780596158118.do

[4] http://shop.oreilly.com/product/0636920027072.do

[5] http://shop.oreilly.com/product/0636920020219.do

[6]
http://www.packtpub.com/numpy-1-5-using-real-world-examples-beginners-guide/book

[7] http://www.packtpub.com/numpy-for-python-cookbook/book

[8] https://www.edx.org/courses/MITx/6.00x/2013_Spring/about

[9]
http://mitpress.mit.edu/books/introduction-computation-and-programming-using-python
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From rosuav at gmail.com  Thu May 30 08:32:19 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 22:32:19 +1000
Subject: Python teaching book recommendations: 3.3+ and with exercises
In-Reply-To: <CAMEax75KY2xKTsJ2yCYJw8A5kg6hVwFB2TgH+bpFfuVnu913KA@mail.gmail.com>
References: <mailman.1244.1367505416.3114.python-list@python.org>
	<zCMgt.166784$5w6.61833@fx05.fr7>
	<CAPTjJmoxHENF7wBjnih=6_w9J_ca=SzEo0V70y4g8dvdq42QhQ@mail.gmail.com>
	<CAMEax75KY2xKTsJ2yCYJw8A5kg6hVwFB2TgH+bpFfuVnu913KA@mail.gmail.com>
Message-ID: <CAPTjJmqOoBFWT=3D66SHRE0JRhWCemmYe8_G-_yS3bL4VKXXGg@mail.gmail.com>

On Sat, May 4, 2013 at 12:54 AM, TP <wingusr at gmail.com> wrote:
> Or maybe Think Python. A *lot* drier presentation than Python for Kids --
> after all, the subtitle which I forgot to mention is "How to Think Like a
> Computer Scientist". Newer than Summerfield
> , but only 1/3 the length
> . Since I've only skimmed both I find it hard to recommend one over the
> other.

Many thanks to those who responded.

A decision has been reached, and Think Python is being used. We'll see
how it goes!

I knew I could trust this list for good advice :)

ChrisA


From ethan at stoneleaf.us  Fri May  3 13:50:07 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Fri, 03 May 2013 10:50:07 -0700
Subject: Python teaching book recommendations: 3.3+ and with exercises
In-Reply-To: <CAPTjJmoJ8cC0wvv04gnJc77X-3uztvaX27Q_Y7oWbtJZYpRh6w@mail.gmail.com>
References: <CAPTjJmoJ8cC0wvv04gnJc77X-3uztvaX27Q_Y7oWbtJZYpRh6w@mail.gmail.com>
Message-ID: <5183F8CF.9040801@stoneleaf.us>

Try

http://inventwithpython.com/

Al Sweigert is the author, and he has three free ebooks there, and you can also purchase the paper versions if you like. 
  Looks like it targets 3.1.

--
~Ethan~


From l.selmi at icloud.com  Thu May  2 09:50:58 2013
From: l.selmi at icloud.com (leonardo selmi)
Date: Thu, 02 May 2013 15:50:58 +0200
Subject: help to code...
Message-ID: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>

dear python community,

i wrote the following program:

from datetime import datetime
now = datetime.now()
current_month = now.month
current_day = now.day
current_year = now.year
current_hour = now.hour
current_minute = now.minute
current_second = now.second
print str(current_month) + '/' + str(current_day) + '/' + str(current_year) +' '+ 
print str(current_hour) + str(current_minute) + str(current_second)

and i got this error:
Traceback (most recent call last):
  File "runner.py", line 125, in compilecode
  File "python", line 9
    print str(current_month) + '/' + str(current_day) + '/' + str(current_year) +' '+
                                                                                     ^
SyntaxError: invalid syntax

how can i write the last two lines correctly?

thanks!


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From rosuav at gmail.com  Thu May  2 10:59:03 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 3 May 2013 00:59:03 +1000
Subject: help to code...
In-Reply-To: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
References: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
Message-ID: <CAPTjJmpvAmG_wFnz-6OWELi6C8cYj-2Cgmn_GyR=BsC4=aD1SQ@mail.gmail.com>

On Thu, May 2, 2013 at 11:50 PM, leonardo selmi <l.selmi at icloud.com> wrote:
> dear python community,
>
> i wrote the following program:
>
> print str(current_month) + '/' + str(current_day) + '/' + str(current_year)
> +' '+
> print str(current_hour) + str(current_minute) + str(current_second)
>
> SyntaxError: invalid syntax
>
> how can i write the last two lines correctly?

You're doing two separate print statements. Either join them into one
(if you want it to be one line), or drop the last + on the first line,
which is causing your syntax error. But there's an even easier way to
do this: Use formatted printing.

print("%d/%d/%d
%d%d%d"%(current_month,current_day,current_year,current_hour,current_minute,current_second))

Or, since you're getting those straight from 'now':

print("%d/%d/%d
%d%d%d"%(now.month,now.day,now.year,now.hour,now.minute,now.second))

I strongly suspect that you want to put delimiters in the time, though
(colons, perhaps?). It'd be really nice, by the way, if you'd avoid
the messy American format date with the month first; put the year
first and it's unambiguous!

ChrisA


From breamoreboy at yahoo.co.uk  Thu May  2 11:26:17 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 02 May 2013 16:26:17 +0100
Subject: help to code...
In-Reply-To: <CAPTjJmpvAmG_wFnz-6OWELi6C8cYj-2Cgmn_GyR=BsC4=aD1SQ@mail.gmail.com>
References: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
	<CAPTjJmpvAmG_wFnz-6OWELi6C8cYj-2Cgmn_GyR=BsC4=aD1SQ@mail.gmail.com>
Message-ID: <klu0io$vss$1@ger.gmane.org>

On 02/05/2013 15:59, Chris Angelico wrote:
> On Thu, May 2, 2013 at 11:50 PM, leonardo selmi <l.selmi at icloud.com> wrote:
>> dear python community,
>>
>> i wrote the following program:
>>
>> print str(current_month) + '/' + str(current_day) + '/' + str(current_year)
>> +' '+
>> print str(current_hour) + str(current_minute) + str(current_second)
>>
>> SyntaxError: invalid syntax
>>
>> how can i write the last two lines correctly?
>
> You're doing two separate print statements. Either join them into one
> (if you want it to be one line), or drop the last + on the first line,
> which is causing your syntax error. But there's an even easier way to
> do this: Use formatted printing.
>
> print("%d/%d/%d
> %d%d%d"%(current_month,current_day,current_year,current_hour,current_minute,current_second))
>
> Or, since you're getting those straight from 'now':
>
> print("%d/%d/%d
> %d%d%d"%(now.month,now.day,now.year,now.hour,now.minute,now.second))
>
> I strongly suspect that you want to put delimiters in the time, though
> (colons, perhaps?). It'd be really nice, by the way, if you'd avoid
> the messy American format date with the month first; put the year
> first and it's unambiguous!
>
> ChrisA
>

Better IMHO is to use strftime 
http://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior 
so the complete code could be

from datetime import datetime
print(datetime.now().strftime('%m/%Y/%d %H %m %S'))

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From python at mrabarnett.plus.com  Thu May  2 11:37:06 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 02 May 2013 16:37:06 +0100
Subject: help to code...
In-Reply-To: <klu0io$vss$1@ger.gmane.org>
References: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
	<CAPTjJmpvAmG_wFnz-6OWELi6C8cYj-2Cgmn_GyR=BsC4=aD1SQ@mail.gmail.com>
	<klu0io$vss$1@ger.gmane.org>
Message-ID: <51828822.5080102@mrabarnett.plus.com>

On 02/05/2013 16:26, Mark Lawrence wrote:
> On 02/05/2013 15:59, Chris Angelico wrote:
>> On Thu, May 2, 2013 at 11:50 PM, leonardo selmi <l.selmi at icloud.com> wrote:
>>> dear python community,
>>>
>>> i wrote the following program:
>>>
>>> print str(current_month) + '/' + str(current_day) + '/' + str(current_year)
>>> +' '+
>>> print str(current_hour) + str(current_minute) + str(current_second)
>>>
>>> SyntaxError: invalid syntax
>>>
>>> how can i write the last two lines correctly?
>>
>> You're doing two separate print statements. Either join them into one
>> (if you want it to be one line), or drop the last + on the first line,
>> which is causing your syntax error. But there's an even easier way to
>> do this: Use formatted printing.
>>
>> print("%d/%d/%d
>> %d%d%d"%(current_month,current_day,current_year,current_hour,current_minute,current_second))
>>
>> Or, since you're getting those straight from 'now':
>>
>> print("%d/%d/%d
>> %d%d%d"%(now.month,now.day,now.year,now.hour,now.minute,now.second))
>>
>> I strongly suspect that you want to put delimiters in the time, though
>> (colons, perhaps?). It'd be really nice, by the way, if you'd avoid
>> the messy American format date with the month first; put the year
>> first and it's unambiguous!
>>
>> ChrisA
>>
>
> Better IMHO is to use strftime
> http://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior
> so the complete code could be
>
> from datetime import datetime
> print(datetime.now().strftime('%m/%Y/%d %H %m %S'))
>
Except, of course, putting the year first, and using "%m" for the
minutes:

print(datetime.now().strftime('%Y-%m-%d %H:%M:%S'))

:-)



From breamoreboy at yahoo.co.uk  Thu May  2 12:08:45 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 02 May 2013 17:08:45 +0100
Subject: help to code...
In-Reply-To: <51828822.5080102@mrabarnett.plus.com>
References: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
	<CAPTjJmpvAmG_wFnz-6OWELi6C8cYj-2Cgmn_GyR=BsC4=aD1SQ@mail.gmail.com>
	<klu0io$vss$1@ger.gmane.org> <51828822.5080102@mrabarnett.plus.com>
Message-ID: <klu32c$opm$1@ger.gmane.org>

On 02/05/2013 16:37, MRAB wrote:
> On 02/05/2013 16:26, Mark Lawrence wrote:
>> On 02/05/2013 15:59, Chris Angelico wrote:
>>> On Thu, May 2, 2013 at 11:50 PM, leonardo selmi <l.selmi at icloud.com>
>>> wrote:
>>>> dear python community,
>>>>
>>>> i wrote the following program:
>>>>
>>>> print str(current_month) + '/' + str(current_day) + '/' +
>>>> str(current_year)
>>>> +' '+
>>>> print str(current_hour) + str(current_minute) + str(current_second)
>>>>
>>>> SyntaxError: invalid syntax
>>>>
>>>> how can i write the last two lines correctly?
>>>
>>> You're doing two separate print statements. Either join them into one
>>> (if you want it to be one line), or drop the last + on the first line,
>>> which is causing your syntax error. But there's an even easier way to
>>> do this: Use formatted printing.
>>>
>>> print("%d/%d/%d
>>> %d%d%d"%(current_month,current_day,current_year,current_hour,current_minute,current_second))
>>>
>>>
>>> Or, since you're getting those straight from 'now':
>>>
>>> print("%d/%d/%d
>>> %d%d%d"%(now.month,now.day,now.year,now.hour,now.minute,now.second))
>>>
>>> I strongly suspect that you want to put delimiters in the time, though
>>> (colons, perhaps?). It'd be really nice, by the way, if you'd avoid
>>> the messy American format date with the month first; put the year
>>> first and it's unambiguous!
>>>
>>> ChrisA
>>>
>>
>> Better IMHO is to use strftime
>> http://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior
>>
>> so the complete code could be
>>
>> from datetime import datetime
>> print(datetime.now().strftime('%m/%Y/%d %H %m %S'))
>>
> Except, of course, putting the year first, and using "%m" for the
> minutes:
>
> print(datetime.now().strftime('%Y-%m-%d %H:%M:%S'))
>
> :-)
>

Congratulations on spotting my deliberate mistake :)

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From python at mrabarnett.plus.com  Thu May  2 11:04:20 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 02 May 2013 16:04:20 +0100
Subject: help to code...
In-Reply-To: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
References: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
Message-ID: <51828074.6050109@mrabarnett.plus.com>

On 02/05/2013 14:50, leonardo selmi wrote:
> dear python community,
>
> i wrote the following program:
>
> from datetime import datetime
> now = datetime.now()
> current_month = now.month
> current_day = now.day
> current_year = now.year
> current_hour = now.hour
> current_minute = now.minute
> current_second = now.second
> print str(current_month) + '/' + str(current_day) + '/' +
> str(current_year) +' '+
> print str(current_hour) + str(current_minute) + str(current_second)
>
> and i got this error:
> Traceback (most recent call last):
>    File "runner.py", line 125, in compilecode
>    File "python", line 9
>      print str(current_month) + '/' + str(current_day) + '/' + str(current_year) +' '+
>                                                                                       ^
> SyntaxError: invalid syntax
>
> how can i write the last two lines correctly?
>
Look at where the caret (the "^") is pointing; there's a trailing "+".



From bgailer at gmail.com  Thu May  2 18:40:09 2013
From: bgailer at gmail.com (bob gailer)
Date: Thu, 02 May 2013 18:40:09 -0400
Subject: [Python-Help] help to code...
In-Reply-To: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
References: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
Message-ID: <5182EB49.3040805@gmail.com>

On 5/2/2013 9:50 AM, leonardo selmi wrote:
>
Please in future post plain text.

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From matteo.boscolo at boscolini.eu  Fri May  3 02:50:27 2013
From: matteo.boscolo at boscolini.eu (Matteo Boscolo)
Date: Fri, 03 May 2013 08:50:27 +0200
Subject: help to code...
In-Reply-To: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
References: <1F2E5209-2F0F-4DE2-88BC-DB9C2267B0F3@icloud.com>
Message-ID: <51835E33.7040600@boscolini.eu>

The error is self expleined ..

print str(current_month) + '/' + str(current_day) + '/' + 
str(current_year) +' *'+ *

this line have a + at the end,the interpreter need something to add .. 
so remove it and it will work

regards,
Matteo

Il 02/05/2013 15:50, leonardo selmi ha scritto:
> dear python community,
>
> i wrote the following program:
>
> from datetime import datetime
> now = datetime.now()
> current_month = now.month
> current_day = now.day
> current_year = now.year
> current_hour = now.hour
> current_minute = now.minute
> current_second = now.second
> print str(current_month) + '/' + str(current_day) + '/' + 
> str(current_year) +' '+
> print str(current_hour) + str(current_minute) + str(current_second)
>
> and i got this error:
> Traceback (most recent call last):
>   File "runner.py", line 125, in compilecode
>   File "python", line 9
>     print str(current_month) + '/' + str(current_day) + '/' + str(current_year) +' '+
>                                                                                      ^
> SyntaxError: invalid syntax
>
> how can i write the last two lines correctly?
>
> thanks!
>
>
>
>

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From bv8bv8bv8 at gmail.com  Thu May  2 14:46:31 2013
From: bv8bv8bv8 at gmail.com (BV BV)
Date: Thu, 2 May 2013 11:46:31 -0700 (PDT)
Subject: ???????? DID MUHAMMAD AUTHOR THE QURAN
Message-ID: <6e5fef5a-6fe3-4e83-aa9e-59901728d46e@o19g2000vbm.googlegroups.com>

DID MUHAMMAD AUTHOR THE QURAN?







Did Muhammad Author the Quran?



Who authored the Quran?  Someone must have produced it! After all, how
many desert men have stood up in the history of man and given the
world a book like the Quran?  The book has amazing details of past
nations, prophets, and religions as well as accurate scientific
information unavailable at the time. What was the source of all this?
If we were to deny the divine origin of the Quran, we are left with
only a few possibilities:

- The Prophet Muhammad authored it himself.

- He took it from someone else.  In this case, he either took it from
a Jew or a Christian or one of the foreigners in Arabia.  The Meccans
did not bother to accuse him of having taken it from one of them.

A brief response from God is:

?And they say, ?Legends of the former peoples which he has written
down, and they are dictated to him morning and afternoon.? Say, [O
Muhammad], ?It has been revealed by He who knows [every] secret within
the heavens and the earth. Indeed, He is ever Forgiving and
Merciful.?? (Quran 25:5-6)

It was well known to his detractors that Muhammad, who was raised
among them, never learned how to read or write from the time of his
birth.  They knew whom he befriended and where he had traveled; they
acknowledged his integrity and honesty by calling him ?Al-Ameen,? the
Reliable, the Trustworthy, the Honest.[1] Only in their revulsion
against his preaching did they accuse him ? and then it was anything
they could dream up: He was accused of being a sorcerer, a poet and
even an imposter!  They could not make up their minds.  God says:

?Look how they strike for you comparisons; but they have strayed, so
they cannot [find] a way.? (Quran 17:47)

Simply, God is aware of what is in the heavens and the earth, He knows
the past and the present, and reveals the truth to His prophet.

Could Muhammad Have Authored It?

It is impossible that Muhammad could have authored the Quran due to
the following reasons:

First, several occasions presented themselves where he could have
fabricated revelation. For example, after the first revelation came,
people awaited to hear more, but the Prophet did not receive anything
new for months. The Meccans began making fun of him, ?His Lord has
abandoned him!?  This continued until the 93rd chapter, Ad-Doha, was
revealed. The Prophet could have compiled something and presented it
as the latest revelation to end the mockery, but he did not. Also, at
one point during his prophethood, some of the hypocrites accused his
beloved wife Aisha of being unchaste. The Prophet could have easily
fabricated something to free her of blame, but he waited for many
excruciating days, all spent in pain, mockery, and anguish, until
revelation came from God freeing her from the accusation.

Second, there is internal evidence within the Quran that Muhammad was
not its author. Several verses criticized him, and were on occasion
strongly worded. How can an imposter prophet blame himself when it may
run him into the danger of losing the respect, perhaps following, of
his followers? Here are some examples:

?O Prophet! Why do you prohibit [yourself from] what God has made
lawful for you, seeking the approval of your wives? And God is
Forgiving and Merciful.? (Quran 66:1)

??while you concealed within yourself that which God is to disclose
and you feared the people, while God has more right that you fear
Him..? (Quran 33:43)

?It is not for the Prophet and those who have believed to ask
forgiveness for the polytheists, even if they were relatives, after it
has become clear to them that they are companions of Hellfire.? (Quran
9:113)

?But as for he who came to you striving [for knowledge] while he fears
[God], from him you are distracted.  No!  Indeed, they [these verses]
are a reminder.? (Quran 80:8-11)

If he were to hide anything, he would have hid these verses, but he
recited them faithfully.

?And he [Muhammad] is not a withholder of [knowledge of] the unseen.
And it [the Quran] is not the word of a devil, expelled [from the
heavens].  So where are you going?  It is nothing but a reminder to
the worlds.? (Quran 81:24-27)

The Prophet is cautioned, perhaps warned, in the following verses:

?Indeed, We have revealed to you, [O Muhammad], the Book in truth so
you may judge between the people by that which God has shown you. And
do not be an advocate for the deceitful. And seek forgiveness of God.
Indeed, God is ever Forgiving and Merciful. And do not argue on behalf
of those who deceive themselves. Indeed, God loves not the one who is
a habitually sinful deceiver.  They conceal [their evil intentions and
deeds] from the people, but they cannot conceal [them] from God, and
He is with them [in His knowledge] when they spend the night in such
as He does not accept of speech.  And God ever is encompassing of what
they do,. Here you are ? those who argue on their behalf in [this]
worldly life ? but who will argue with God for them on the Day of
Resurrection, or who will [then] be their representative?  And whoever
does a wrong or wrongs himself but then seeks forgiveness of God will
find God Forgiving and Merciful. And whoever earns [i.e., commits] a
sin only earns it against himself. And God is ever Knowing and Wise.
But whoever earns an offense or a sin and then blames it on an
innocent [person] has taken upon himself slander and manifest sin. And
if it was not for the favor of God upon you, [O Muhammad], and His
mercy, a group of them would have determined to mislead you.  But they
do not mislead except themselves, and they will not harm you at all.
And God has revealed to you the Book and wisdom and has taught you
that which you did not know. And ever has the favor of God upon you
been great.? (Quran 4:105-113)

These verses explain a situation in which a man from the Muslim
inhabitants of Medina stole a piece of armor and hid it in the
property of his Jewish neighbor.  When the owners of the armor caught
up with him he denied any wrongdoing, and the armor was discovered
with the Jewish man.  He, however, pointed to his Muslim neighbor,
also denying his involvement in the crime. The people from the
Muslim?s tribe went to the Prophet to plead on his behalf, and the
Prophet began to incline towards them till the above verses were
revealed clearing the Jewish man of wrongdoing.  All this despite the
Jew?s rejection of Muhammad?s prophethood!  The verses instructed
Prophet Muhammad himself not to side with the deceitful!  The verses:

??and do not be an advocate for the deceitful and seek forgiveness of
God?and if it was not for the favor of God upon you, [O Muhammad], and
His mercy, a group of them would have determined to mislead you.?

If Muhammad himself authored the Quran, thus being a lying imposter,
he would have made sure that there was nothing in existence which
could jeopardize the gaining of followers and supporters.  The fact
that the Quran, on various occasions, reprimands the Prophet in
certain issues in which he had made in incorrect judgment is in itself
a proof that it was not authored by him.


[1] ?Muhammad: His Life Based on the Earliest Sources? by Martin
Lings, p. 34.





http://www.islamreligion.com/articles/338/



thank you


From karthik.sharma at gmail.com  Thu May  2 18:14:22 2013
From: karthik.sharma at gmail.com (karthik.sharma at gmail.com)
Date: Thu, 2 May 2013 15:14:22 -0700 (PDT)
Subject: query from sqlalchemy returns AttributeError: 'NoneType' object
Message-ID: <cc9b6315-dcd5-42c7-a5ca-e5df1d51348c@googlegroups.com>

from pox.core import core
    import pox.openflow.libopenflow_01 as of
    import re
    import datetime
    
    from sqlalchemy import create_engine, ForeignKey
    from sqlalchemy import Column, Date, Integer, String
    from sqlalchemy.ext.declarative import declarative_base
    from sqlalchemy.orm import relationship, backref
    from sqlalchemy import create_engine
    from sqlalchemy.orm import sessionmaker
    from sqlalchemy.sql.expression import exists
    
    log = core.getLogger()
    
    engine = create_engine('sqlite:///nwtopology.db', echo=False)
    Base = declarative_base()
    Session = sessionmaker(bind=engine)
    session = Session()
    
    ########################################################################
    class SourcetoPort(Base):
        """"""
        __tablename__ = 'source_to_port'
        id = Column(Integer, primary_key=True)
        port_no        = Column(Integer)
        src_address    = Column(String,index=True)
    
        #----------------------------------------------------------------------
        def __init__(self, src_address,port_no):
            """"""
            self.src_address = src_address    
    	self.port_no     = port_no
            
    ########################################################################
    
    #create tables
    Base.metadata.create_all(engine)
    
    class Tutorial (object):
      def __init__ (self, connection):
        self.connection = connection
        connection.addListeners(self)
        # Use this table to keep track of which ethernet address is on
        # which switch port (keys are MACs, values are ports).
        self.mac_to_port = {} 
        self.matrix={} 
    	
        #This will keep track of the traffic matrix. 
        #matrix[i][j]=number of times a packet from i went to j
      
      def send_packet (self, buffer_id, raw_data, out_port, in_port):
        #print "calling send_packet"
        #Sends a packet out of the specified switch port.
        msg = of.ofp_packet_out()
        msg.in_port = in_port
        msg.data = raw_data
        # Add an action to send to the specified port
        action = of.ofp_action_output(port = out_port)
        msg.actions.append(action)
        # Send message to switch
        self.connection.send(msg)
    
      def act_like_hub (self, packet, packet_in):
        #flood packet on all ports
        self.send_packet(packet_in.buffer_id, packet_in.data,
                         of.OFPP_FLOOD, packet_in.in_port)
    
      def act_like_switch (self, packet, packet_in):
        """
        Implement switch-like behavior.
        """
        # Learn the port for the source MAC
        #print "RECIEVED FROM PORT ",packet_in.in_port , "SOURCE ",packet.src
        # create a Session
        #Session = sessionmaker(bind=engine)
        #session = Session()
        self.mac_to_port[packet.src]=packet_in.in_port
        #if self.mac_to_port.get(packet.dst)!=None:
        #print "count for dst",session.query(SourcetoPort).filter_by(src_address=str(packet.dst)).count(),str(packet.dst)
        #if session.query(SourcetoPort).filter_by(src_address=str(packet.dst)).count():
        if session.query(exists().where(SourcetoPort.src_address == str(packet.dst))).scalar() is not None:
          	   #send this packet
    	   print "got info from the database"
    	   q_res = session.query(SourcetoPort).filter_by(src_address=str(packet.dst)).one()
    	   self.send_packet(packet_in.buffer_id, packet_in.data,q_res.port_no, packet_in.in_port)
               #create a flow modification message
          	   msg = of.ofp_flow_mod()
          	   #set the fields to match from the incoming packet
    	   msg.match = of.ofp_match.from_packet(packet)
               #send the rule to the switch so that it does not query the controller again.
               msg.actions.append(of.ofp_action_output(port=q_res.port_no))
               #push the rule
               self.connection.send(msg)
        else:
               #flood this packet out as we don't know about this node.
               print "flooding the first packet"
               self.send_packet(packet_in.buffer_id, packet_in.data,
                           of.OFPP_FLOOD, packet_in.in_port)
    	   #self.matrix[(packet.src,packet.dst)]+=1	 
    	   entry = SourcetoPort(src_address=str(packet.src) , port_no=packet_in.in_port)
               #add the record to the session object
               session.add(entry)
               #add the record to the session object
               session.commit()
    
      def _handle_PacketIn (self, event):
        """
        Handles packet in messages from the switch.
        """
        packet = event.parsed # This is the parsed packet data.
        if not packet.parsed:
          log.warning("Ignoring incomplete packet")
          return
        packet_in = event.ofp # The actual ofp_packet_in message.
    
        #self.act_like_hub(packet, packet_in)
        self.act_like_switch(packet, packet_in)
    
    def launch ():
      """
      Starts the component
      """
      def start_switch (event):
        log.debug("Controlling %s" % (event.connection,))
        Tutorial(event.connection)
      core.openflow.addListenerByName("ConnectionUp", start_switch)



When I run the above code I get the following error:



The problem that I am facing is for some reason if I use 

    if session.query(exists().where(SourcetoPort.src_address == str(packet.dst))).scalar() is not None:

    in place of count query.

    #if session.query(SourcetoPort).filter_by(src_address=str(packet.dst)).count():

The querying from the database

    q_res = session.query(SourcetoPort).filter_by(src_address=str(packet.dst)).first()
    self.send_packet(packet_in.buffer_id, packet_in.data,q_res.port_no, packet_in.in_port)

is giving the following error:

    DEBUG:core:POX 0.1.0 (betta) going up...
    DEBUG:core:Running on CPython (2.7.3/Aug 1 2012 05:14:39)
    DEBUG:core:Platform is Linux-3.5.0-23-generic-x86_64-with-Ubuntu-12.04-precise
    INFO:core:POX 0.1.0 (betta) is up.
    DEBUG:openflow.of_01:Listening on 0.0.0.0:6633
    INFO:openflow.of_01:[00-00-00-00-00-02 1] connected
    DEBUG:tutorial:Controlling [00-00-00-00-00-02 1]
    got info from the database
    ERROR:core:Exception while handling Connection!PacketIn...
    Traceback (most recent call last):
      File "/home/karthik/pox/pox/lib/revent/revent.py", line 234, in raiseEventNoErrors
        return self.raiseEvent(event, *args, **kw)
      File "/home/karthik/pox/pox/lib/revent/revent.py", line 281, in raiseEvent
        rv = event._invoke(handler, *args, **kw)
      File "/home/karthik/pox/pox/lib/revent/revent.py", line 159, in _invoke
        return handler(self, *args, **kw)
      File "/home/karthik/pox/tutorial.py", line 118, in _handle_PacketIn
        self.act_like_switch(packet, packet_in)
      File "/home/karthik/pox/tutorial.py", line 86, in act_like_switch
        self.send_packet(packet_in.buffer_id, packet_in.data,q_res.port_no, packet_in.in_port)
    AttributeError: 'NoneType' object has no attribute 'port_no'
    got info from the database
    ERROR:core:Exception while handling Connection!PacketIn...


From python at mrabarnett.plus.com  Thu May  2 19:17:41 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 03 May 2013 00:17:41 +0100
Subject: query from sqlalchemy returns AttributeError: 'NoneType' object
In-Reply-To: <cc9b6315-dcd5-42c7-a5ca-e5df1d51348c@googlegroups.com>
References: <cc9b6315-dcd5-42c7-a5ca-e5df1d51348c@googlegroups.com>
Message-ID: <5182F415.8080003@mrabarnett.plus.com>

On 02/05/2013 23:14, karthik.sharma at gmail.com wrote:
[snip]
>
>      ########################################################################
>      class SourcetoPort(Base):
>          """"""
>          __tablename__ = 'source_to_port'
>          id = Column(Integer, primary_key=True)
>          port_no        = Column(Integer)
>          src_address    = Column(String,index=True)
>
>          #----------------------------------------------------------------------
>          def __init__(self, src_address,port_no):
>              """"""
>              self.src_address = src_address

The indentation of this line looks wrong:

>      	   self.port_no     = port_no
>
>      ########################################################################
[snip]



From davea at davea.name  Thu May  2 19:29:11 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 02 May 2013 19:29:11 -0400
Subject: query from sqlalchemy returns AttributeError: 'NoneType' object
In-Reply-To: <cc9b6315-dcd5-42c7-a5ca-e5df1d51348c@googlegroups.com>
References: <cc9b6315-dcd5-42c7-a5ca-e5df1d51348c@googlegroups.com>
Message-ID: <5182F6C7.2030108@davea.name>

On 05/02/2013 06:14 PM, karthik.sharma at gmail.com wrote:
> from pox.core import core
>      import pox.openflow.libopenflow_01 as of
>      import re
>      import datetime
>


You're mixing tabs and space, so all bets are off.  No promise that the 
compiler will interpret the indentations the same way you see them.

Use your editor to expand all the tabs to space, then check whether the 
code still makes sense to you.  Then if you want to post a new question, 
show us the new version of code.

Also this time post the error traceback that matches the version of the 
code you're showing us.

And don't bother double-posting on tutor.

-- 
DaveA


From titanix88 at gmail.com  Thu May  2 19:34:40 2013
From: titanix88 at gmail.com (Mr. Joe)
Date: Fri, 3 May 2013 05:34:40 +0600
Subject: Debugging difficulty in python with __getattr__, decorated properties
	and AttributeError.
Message-ID: <CAJxooseGiyPRq2rZWZ+Wcz6x94yCZodQKrSAWEPBVPme-0qcpw@mail.gmail.com>

Is there any way to raise the original exception that made the call to
__getattr__? I seem to stumble upon a problem where multi-layered attribute
failure gets obscured due to use of __getattr__. Here's a dummy code to
demonstrate my problems:
"""
import traceback


class BackupAlphabet(object):
    pass


class Alphabet(object):
    @property
    def a(self):
        return backupalphabet.a


    def __getattr__(self, name):
        if name == "b":
            return "banana"

        raise AttributeError(
            "'{0} object has no attribute '{1}'"
            .format(self.__class__.__name__, name))


alphabet = Alphabet()
backupalphabet = BackupAlphabet()

print(alphabet.a)
print(alphabet.b)
"""

Running the above code produces this:
"""
Traceback (most recent call last):
  File "example.py", line 26, in <module>
    print(alphabet.a)
  File "example.py", line 20, in __getattr__
    .format(self.__class__.__name__, name))
AttributeError: 'Alphabet object has no attribute 'a'
"""

While it's easy enough to identify the problem here, the traceback is
rather unhelpful in complex situations. Any comments?

Regards,
TB
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From steve+comp.lang.python at pearwood.info  Thu May  2 20:20:39 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 03 May 2013 00:20:39 GMT
Subject: Debugging difficulty in python with __getattr__, decorated
	properties and AttributeError.
References: <mailman.1257.1367537690.3114.python-list@python.org>
Message-ID: <518302d7$0$29971$c3e8da3$5496439d@news.astraweb.com>

On Fri, 03 May 2013 05:34:40 +0600, Mr. Joe wrote:

> Is there any way to raise the original exception that made the call to
> __getattr__? 

No. There is some discussion on the Python-Dev mailing list about adding 
better error reporting to AttributeError, but that may not go anywhere, 
and even if it does, it won't help you until you have dropped all support 
for versions below Python 3.4 or 3.5.



> class BackupAlphabet(object):
>     pass
> 
> 
> class Alphabet(object):
>     @property
>     def a(self):
>         return backupalphabet.a

This raises AttributeError. Since __getattr__ uses AttributeError to 
decide whether or not the name exists, the behaviour shown is correct: 
Alphabet.a does not exist, as far as the Python semantics of attribute 
access are concerned.

Either write better code *wink* that doesn't raise AttributeError from 
inside properties, or wrap them with something like this:

class Alphabet(object):
    @property
    def a(self):
        try:
            return backupalphabet.a
        except AttributeError:
            raise MyCustomError

where MyCustomError does NOT inherit from AttributeError.

If you're doing this a lot, you can create a decorator to do the wrapping.



-- 
Steven


From titanix88 at gmail.com  Fri May  3 03:52:23 2013
From: titanix88 at gmail.com (Mr. Joe)
Date: Fri, 3 May 2013 13:52:23 +0600
Subject: Debugging difficulty in python with __getattr__, decorated
	properties and AttributeError.
In-Reply-To: <518302d7$0$29971$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.1257.1367537690.3114.python-list@python.org>
	<518302d7$0$29971$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAJxoosf4NLafEKHy3CSk1GBSO2RCxk_9SsxPHraOa-JU45jByg@mail.gmail.com>

Thanks for clearing up. Developers of python should address this issue, in
my opinion. 3.4/3.5 maybe, but better late than never.

Recently, I've been beaten back for using some exotic features of python.
One is this[ Took me hours to get to the bottom ]. The other one is
'property' decorator. I was using it extensively until I needed to make a
child class. Then I came to know that 'property' does not play well
with polymorphic code. :( I resorted to some lambda hacks learned from
stackoverflow.com to solve the problem. I know that it's the correct way
for decorators to work, but still, it would be nice to have a language
level solution.
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From dieter at handshake.de  Sat May  4 01:56:22 2013
From: dieter at handshake.de (dieter)
Date: Sat, 04 May 2013 07:56:22 +0200
Subject: Debugging difficulty in python with __getattr__,
	decorated properties and AttributeError.
References: <mailman.1257.1367537690.3114.python-list@python.org>
	<518302d7$0$29971$c3e8da3$5496439d@news.astraweb.com>
	<CAJxoosf4NLafEKHy3CSk1GBSO2RCxk_9SsxPHraOa-JU45jByg@mail.gmail.com>
Message-ID: <87a9obz3sp.fsf@handshake.de>

"Mr. Joe" <titanix88 at gmail.com> writes:

> ...
> Then I came to know that 'property' does not play well
> with polymorphic code. :(

Can you elaborate?

I like "polymorphic code" and decorators (such a "property")
never met a problem with the two working nicely together.

> I resorted to some lambda hacks learned from
> stackoverflow.com to solve the problem. I know that it's the correct way
> for decorators to work, but still, it would be nice to have a language
> level solution.

There are two approaches: change the language or learn how the language works.

I am very happy that the Python developers try hard to retain backward
compatible and, consequently, are very reluctant towards language changes.
I would hate should the decorator behavior change in an incompatible
way.

On the other hand, decorators are very easy to understand: they are
just syntactic sugar:

     @<dec_expression>
     def f(...): ...

  is equivalent to:

     def f(...): ...
     f = <dec_expression>(f)

The "property" decorator uses an additional concept: "descriptor"s.
A "descriptor" allows you to customize attribute access.

These two concepts graped, the "property" decorator should no longer
cause surprises -- even in "polymorphic code".



From steve+comp.lang.python at pearwood.info  Sat May  4 02:29:22 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 04 May 2013 06:29:22 GMT
Subject: Debugging difficulty in python with __getattr__, decorated
	properties and AttributeError.
References: <mailman.1257.1367537690.3114.python-list@python.org>
	<518302d7$0$29971$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1265.1367567552.3114.python-list@python.org>
Message-ID: <5184aac2$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 03 May 2013 13:52:23 +0600, Mr. Joe wrote:

> Thanks for clearing up. Developers of python should address this issue,
> in my opinion. 3.4/3.5 maybe, but better late than never.
> 
> Recently, I've been beaten back for using some exotic features of
> python. 

What do you consider "exotic"? Neither properties nor __getattr__ are 
exotic, although of course like all features of a language they have 
their own quirks.


> One is this[ Took me hours to get to the bottom ].

Well, of course hindsight is 20:20, and I don't know how complicated your 
actual code is, but "hours" seems a bit poor. I could believe half an 
hour. Maybe an hour. But of course everything is easy to the guy who 
doesn't have to do it.


> The other one
> is 'property' decorator. I was using it extensively until I needed to
> make a child class. Then I came to know that 'property' does not play
> well with polymorphic code. :( 

I don't understand what you are trying to say. Properties can be as 
polymorphic as any other Python function.


> I resorted to some lambda hacks learned
> from stackoverflow.com to solve the problem. 

That's not a good sign. Any sentence containing "hacks" and 
"stackoverflow" is a warning that you're probably doing something wrong.



-- 
Steven


From titanix88 at gmail.com  Tue May 14 11:09:54 2013
From: titanix88 at gmail.com (Mr. Joe)
Date: Tue, 14 May 2013 21:09:54 +0600
Subject: Debugging difficulty in python with __getattr__, decorated
	properties and AttributeError.
In-Reply-To: <5184aac2$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.1257.1367537690.3114.python-list@python.org>
	<518302d7$0$29971$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1265.1367567552.3114.python-list@python.org>
	<5184aac2$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAJxoosf=ZMK2cVuGdYWH7Hv5tS9pN+ZKzhFvKCerbQuNrK_y5w@mail.gmail.com>

Sorry for digging this old topic back. I see that my "'property' does not
play well with polymorphic code" comment generated some controversy. So
here's something in my defense:

Here's the link to stackoveflow topic I am talking about:

http://stackoverflow.com/questions/237432/python-properties-and-inheritance

The solution that fits my taste:
http://stackoverflow.com/a/14349742

A related blogpost:

http://requires-thinking.blogspot.com/2006/03/note-to-self-python-properties-are-non.html

Yes, I like decorators and descriptors. I also like the ability to create a
"virtual property" in a python class by binding a bunch of methods as
setter/getter. But I find the implementation of this "virtual property
feature" a bit awkward sometimes - every time I need to override a
getter/setter in a child class, I need to decorate them again. Some of you
may like this "explicitness", but I don't.

To Steven D'Aprano: Seriously, what's all the bashing in your last reply
about? You dissected my "thank-you reply" more strictly than the python
interpreter checking for syntax errors. Not in a mood for fight, but I find
your opinions about "bug finding time", "hacks" and "stackoverflow" quite
silly.
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From dieter at handshake.de  Wed May 15 02:15:53 2013
From: dieter at handshake.de (dieter)
Date: Wed, 15 May 2013 08:15:53 +0200
Subject: Debugging difficulty in python with __getattr__,
	decorated properties and AttributeError.
References: <mailman.1257.1367537690.3114.python-list@python.org>
	<518302d7$0$29971$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1265.1367567552.3114.python-list@python.org>
	<5184aac2$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<CAJxoosf=ZMK2cVuGdYWH7Hv5tS9pN+ZKzhFvKCerbQuNrK_y5w@mail.gmail.com>
Message-ID: <87bo8cvkdi.fsf@handshake.de>

"Mr. Joe" <titanix88 at gmail.com> writes:
> ...
> Sorry for digging this old topic back. I see that my "'property' does not
> play well with polymorphic code" comment generated some controversy. So
> here's something in my defense:

I did not intend to "attack" you.

> ...
> Yes, I like decorators and descriptors. I also like the ability to create a
> "virtual property" in a python class by binding a bunch of methods as
> setter/getter. But I find the implementation of this "virtual property
> feature" a bit awkward sometimes - every time I need to override a
> getter/setter in a child class, I need to decorate them again. Some of you
> may like this "explicitness", but I don't.

True, I have been hit by this, too - not with "property" but with
other decorators (those for caching).
But, after reflection, I came to the conclusion that I should be
happy with this feature:

  If Python would automatically redecorate overridden methods in a derived
  class, I would have no control over the process. What if I need
  the undecorated method or a differently decorated method (an
  uncached or differently cached method, in my case)?

Your getter/setter use case can quite easily be solved
with a class "DelayedMethodAccessor":

  class DelayedMethodAccess(object):
    """
    def __init__(self, name): self.__name = name
    def __call__(self, inst, *args, **kw): 
      return getattr(inst, self.__name)(*args, **kw)

You can then use:

   prop = property(DelayedMethodAccess("<getter_name>"), ...)

Or define a new decorator "property_by_name" and then
use

   prop = property_by_name("<getter_name>", ...)

Of course, this requires that the property name and the getter/setter names
differ, but this should be naturally enough.


Python's current behavior is very natural once you know that
decorators are just syntactic sugar and

   @<decorator_expression>
   def <f>...

simply means:

   def <f>...
   f = <decorator_expressen>(f)

True, this is no perfect fit for all use cases - but
such a fit (if it existed at all) would have to be so complex
that only experts could understand it.



From titanix88 at gmail.com  Wed May 15 12:38:10 2013
From: titanix88 at gmail.com (Mr. Joe)
Date: Wed, 15 May 2013 22:38:10 +0600
Subject: Debugging difficulty in python with __getattr__, decorated
	properties and AttributeError.
In-Reply-To: <87bo8cvkdi.fsf@handshake.de>
References: <mailman.1257.1367537690.3114.python-list@python.org>
	<518302d7$0$29971$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1265.1367567552.3114.python-list@python.org>
	<5184aac2$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<CAJxoosf=ZMK2cVuGdYWH7Hv5tS9pN+ZKzhFvKCerbQuNrK_y5w@mail.gmail.com>
	<87bo8cvkdi.fsf@handshake.de>
Message-ID: <CAJxoosePZ5xahdcgnfh-z+XbAvO6Nm9k1y+yGXcNW89Kmhydew@mail.gmail.com>

On Wed, May 15, 2013 at 12:15 PM, dieter <dieter at handshake.de> wrote:
>
>   If Python would automatically redecorate overridden methods in a derived
>   class, I would have no control over the process. What if I need
>   the undecorated method or a differently decorated method (an
>   uncached or differently cached method, in my case)?
>

On a second thought, I am convinced by your argument.

> Your getter/setter use case can quite easily be solved
> with a class "DelayedMethodAccessor":
>
>   class DelayedMethodAccess(object):
>     """
>     def __init__(self, name): self.__name = name
>     def __call__(self, inst, *args, **kw):
>       return getattr(inst, self.__name)(*args, **kw)
>
> You can then use:
>
>    prop = property(DelayedMethodAccess("<getter_name>"), ...)
>
> Or define a new decorator "property_by_name" and then
> use
>
>    prop = property_by_name("<getter_name>", ...)
>
> Of course, this requires that the property name and the getter/setter
names
> differ, but this should be naturally enough.
>
>
> Python's current behavior is very natural once you know that
> decorators are just syntactic sugar and
>
>    @<decorator_expression>
>    def <f>...
>
> simply means:
>
>    def <f>...
>    f = <decorator_expressen>(f)
>
> True, this is no perfect fit for all use cases - but
> such a fit (if it existed at all) would have to be so complex
> that only experts could understand it.

Thanks for these really nice patterns. They fits my problem very well.
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From dreadpiratejeff at gmail.com  Thu May  2 21:54:29 2013
From: dreadpiratejeff at gmail.com (J)
Date: Thu, 2 May 2013 21:54:29 -0400
Subject: question about try/except blocks
Message-ID: <CAFB6qZsG6nns=_Vn5Fk6M8fvCVY_Ykh8ttH+r9Euz1+ed+iCRA@mail.gmail.com>

I have this function in a class:

 def write_file(self, data, dest):
        with open(dest, 'wb', 0) as outfile:
            try:
                print("IN WRITE_FILE")
                outfile.write(self.data)
            except IOError as exc:
                logging.error("Unable to write data to %s: %s", dest, exc)
                return False
            else:
                outfile.flush()
                os.fsync(outfile.fileno())
                return True


Which is simply called like this:
test.write_file(test.data, target_file)

However, when this is called on a read-only filesystem, it throws an OSError:

  File "./scripts/removable_storage_test", line 118, in write_file
    with open(dest, 'wb', 0) as outfile:
OSError: [Errno 30] Read-only file system:
'/media/bladernr/5747-AD2E/tmpfbzsxk.0'

So what I am not sure of is how to handle this?

Would it be better to wrap the call and catch the OSError there, or
wrap the whole with open() block in the function itself?

My thought is to wrap the with open() call in the function so that I'm
not wrapping the function call every time I use the class somewhere,
but then I am not sure of that as it leads to nested try blocks like
so:

try:
    with open(dest, 'wb', 0) as outfile:
        try:
            stuff
        except IOError as exec:
            more stuff
        else:
            other stuff
except OSError as exc:
     error handling stuff
     return False


I think, functionally, that should work, but should nested try/except
blocks be avoided?


From jeanpierreda at gmail.com  Thu May  2 22:23:11 2013
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Thu, 2 May 2013 22:23:11 -0400
Subject: question about try/except blocks
In-Reply-To: <CAFB6qZsG6nns=_Vn5Fk6M8fvCVY_Ykh8ttH+r9Euz1+ed+iCRA@mail.gmail.com>
References: <CAFB6qZsG6nns=_Vn5Fk6M8fvCVY_Ykh8ttH+r9Euz1+ed+iCRA@mail.gmail.com>
Message-ID: <CABicbJKCtbkR4p1bDW069FnRyqoQSGREqAofa+PYajU0BX9rZg@mail.gmail.com>

On Thu, May 2, 2013 at 9:54 PM, J <dreadpiratejeff at gmail.com> wrote:
> Would it be better to wrap the call and catch the OSError there, or
> wrap the whole with open() block in the function itself?
>
> My thought is to wrap the with open() call in the function so that I'm
> not wrapping the function call every time I use the class somewhere,
> but then I am not sure of that as it leads to nested try blocks like
> so:

It definitely shouldn't be done that way, since you might catch
exceptions in other circumstances too. Try this:

try:
    f = open(dest, 'wb', 0)
except OSError as exc:
    ...
with f:
    try:
        ...
    except IOError as exc:
        ...
    else:
        ...

-- Devin

> try:
>     with open(dest, 'wb', 0) as outfile:
>         try:
>             stuff
>         except IOError as exec:
>             more stuff
>         else:
>             other stuff
> except OSError as exc:
>      error handling stuff
>      return False
>
>
> I think, functionally, that should work, but should nested try/except
> blocks be avoided?


From steve+comp.lang.python at pearwood.info  Thu May  2 23:02:34 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 03 May 2013 03:02:34 GMT
Subject: question about try/except blocks
References: <mailman.1259.1367546098.3114.python-list@python.org>
Message-ID: <518328ca$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Thu, 02 May 2013 21:54:29 -0400, J wrote:

> I have this function in a class:
> 
>  def write_file(self, data, dest):
>         with open(dest, 'wb', 0) as outfile:
>             try:
>                 print("IN WRITE_FILE")
>                 outfile.write(self.data)
>             except IOError as exc:
>                 logging.error("Unable to write data to %s: %s", dest,
>                 exc) return False
>             else:
>                 outfile.flush()
>                 os.fsync(outfile.fileno())
>                 return True
[...]
> I think, functionally, that should work, but should nested try/except
> blocks be avoided?


Not particularly. Try/except is cheap to set up, nesting them doesn't 
cost much.

But having said that, your code as given does not protect against rare
but possible errors. For example, just because you can open the file for 
writing doesn't mean you can write to it; just because you can write to 
it doesn't mean flush will succeed; just because flush succeeds doesn't 
mean that syncing to disk will succeed. Any IO operation might fail. 
While you can wrap each one individually, it's probably better to wrap 
the whole lot at once. I'd write it like this:


def write_file(self, data, dest):
    try:
        with open(dest, 'wb', 0) as outfile:
            print("IN WRITE_FILE")
            outfile.write(self.data)
            outfile.flush()
            os.fsync(outfile.fileno())
    except (OSError, IOError) as exc:
        logging.error("Error writing data to %s: %s", dest, exc)
        return False
    return True



File IO is one of the rare exceptions to the idea that try/except blocks 
should wrap the least amount of code possible.



-- 
Steven


From valbendan at outlook.com  Fri May  3 03:16:09 2013
From: valbendan at outlook.com (dabaichi)
Date: Fri, 3 May 2013 15:16:09 +0800
Subject: python2 input
Message-ID: <klvo0t$2blv$1@adenine.netfront.net>

Hello guys:
Do you have found that the built-in input() function is dangerous.
Here is my code(python 2.x only):

a = input("Input anything:")
print("go here")

If I input:
sys.exit(0)
print("go here") will not be execute, and the script will exit.

--- news://freenews.netfront.net/ - complaints: news at netfront.net ---


From steve+comp.lang.python at pearwood.info  Fri May  3 03:29:56 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 03 May 2013 07:29:56 GMT
Subject: python2 input
References: <klvo0t$2blv$1@adenine.netfront.net>
Message-ID: <51836774$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 03 May 2013 15:16:09 +0800, dabaichi wrote:

> Hello guys:
> Do you have found that the built-in input() function is dangerous.


Correct. Use raw_input instead.


-- 
Steven


From rosuav at gmail.com  Fri May  3 03:31:59 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 3 May 2013 17:31:59 +1000
Subject: python2 input
In-Reply-To: <klvo0t$2blv$1@adenine.netfront.net>
References: <klvo0t$2blv$1@adenine.netfront.net>
Message-ID: <CAPTjJmqsokARdfy5ZDpWJJzWPVbzNt8N7mc9YpP5yZo6O73iyQ@mail.gmail.com>

On Fri, May 3, 2013 at 5:16 PM, dabaichi <valbendan at outlook.com> wrote:
> Hello guys:
> Do you have found that the built-in input() function is dangerous.
> Here is my code(python 2.x only):
>
> a = input("Input anything:")
> print("go here")
>
> If I input:
> sys.exit(0)
> print("go here") will not be execute, and the script will exit.

Yeah, that's kinda discovered. In Python 2, you should be using
raw_input() for that kind of thing. In Python 3, raw_input() was
renamed to input(), and if you want the semantics of Py2 input(), it's
eval(input()), which makes it obvious what's going on.

ChrisA


From michele.simionato at gmail.com  Fri May  3 07:24:18 2013
From: michele.simionato at gmail.com (Michele Simionato)
Date: Fri, 3 May 2013 04:24:18 -0700 (PDT)
Subject: Trying to understand the memory occupation of big lists
Message-ID: <e09e5cf1-4df5-4e77-9108-32bc3a1ae07d@googlegroups.com>

I have a memory leak in a program using big arrays. With the goal of debugging it I run into the memory_profiler module. Then I discovered something which is surprising to me. Please consider the following script:

$ cat memtest.py
import gc
from memory_profiler import profile


@profile
def test1():
    a = [0] * 1024 * 1024
    del a
    gc.collect()  # nothing change if I comment this


@profile
def test2():
    for i in range(10):
        a = [0] * 1024 * 1024
        del a
    gc.collect()  # nothing change if I comment this


test1()
test2()

Here is its output, on a Linux 64 bit machine:

$ python memtest.py
Filename: memtest.py

Line #    Mem usage    Increment   Line Contents
================================================
     5                             @profile
     6     9.250 MB     0.000 MB   def test1():
     7    17.246 MB     7.996 MB       a = [0] * 1024 * 1024
     8     9.258 MB    -7.988 MB       del a
     9     9.258 MB     0.000 MB       gc.collect()  # nothing change if I comment this


Filename: memtest.py

Line #    Mem usage    Increment   Line Contents
================================================
    12                             @profile
    13     9.262 MB     0.000 MB   def test2():
    14    17.270 MB     8.008 MB       for i in range(10):
    15    17.270 MB     0.000 MB           a = [0] * 1024 * 1024
    16    17.270 MB     0.000 MB           del a
    17    17.270 MB     0.000 MB       gc.collect()  # nothing change if I comment this

In the first case the memory is released (even if strangely not
completely, 7.996 != 7.988), in the second case the memory is not. Why it is so? I did expect gc.collect() to free the memory but it is completely ininfluent. In the second cases there are 10 lists with 8 MB each, so
80 MB are allocated and 72 released, but 8 MB are still there apparently.
It does not look like a problem of mem_profile, this is what observe with
top too.

Any ideas?


From davea at davea.name  Fri May  3 08:16:34 2013
From: davea at davea.name (Dave Angel)
Date: Fri, 03 May 2013 08:16:34 -0400
Subject: Trying to understand the memory occupation of big lists
In-Reply-To: <e09e5cf1-4df5-4e77-9108-32bc3a1ae07d@googlegroups.com>
References: <e09e5cf1-4df5-4e77-9108-32bc3a1ae07d@googlegroups.com>
Message-ID: <5183AAA2.7000809@davea.name>

On 05/03/2013 07:24 AM, Michele Simionato wrote:
> I have a memory leak in a program using big arrays.

Actually, big lists.  Python also has arrays, and they're entirely 
different.

With the goal of debugging it I run into the memory_profiler module. 
Then I discovered something which is surprising to me. Please consider 
the following script:
>
> $ cat memtest.py
> import gc
> from memory_profiler import profile
>
>
> @profile
> def test1():
>      a = [0] * 1024 * 1024
>      del a
>      gc.collect()  # nothing change if I comment this
>
>
> @profile
> def test2():
>      for i in range(10):
>          a = [0] * 1024 * 1024
>          del a
>      gc.collect()  # nothing change if I comment this
>
>
> test1()
> test2()
>
> Here is its output, on a Linux 64 bit machine:
>
> $ python memtest.py
> Filename: memtest.py
>
> Line #    Mem usage    Increment   Line Contents
> ================================================
>       5                             @profile
>       6     9.250 MB     0.000 MB   def test1():
>       7    17.246 MB     7.996 MB       a = [0] * 1024 * 1024
>       8     9.258 MB    -7.988 MB       del a
>       9     9.258 MB     0.000 MB       gc.collect()  # nothing change if I comment this
>
>
> Filename: memtest.py
>
> Line #    Mem usage    Increment   Line Contents
> ================================================
>      12                             @profile
>      13     9.262 MB     0.000 MB   def test2():
>      14    17.270 MB     8.008 MB       for i in range(10):
>      15    17.270 MB     0.000 MB           a = [0] * 1024 * 1024
>      16    17.270 MB     0.000 MB           del a
>      17    17.270 MB     0.000 MB       gc.collect()  # nothing change if I comment this
>
> In the first case the memory is released (even if strangely not
> completely, 7.996 != 7.988), in the second case the memory is not. Why it is so? I did expect gc.collect() to free the memory but it is completely ininfluent. In the second cases there are 10 lists with 8 MB each, so
> 80 MB are allocated and 72 released, but 8 MB are still there apparently.
> It does not look like a problem of mem_profile, this is what observe with
> top too.
>
> Any ideas?
>

I haven't played with profile, so my comments are limited to the direct 
code.

gd.collect() has nothing to do in either of these functions, since the 
memory has already been released by the ref-count logic.  Only in the 
case of a circular reference is the gc.collect() useful.  If you want to 
see gc.collect() in action create two large objects that reference each 
other and a small one that references one of them.  Del the first two 
and then the third, and the memory cannot be released since the ref 
counts are nonzero.  Then do a gc.collect() which will realize that you 
have no way to reference either of the two large objects.

I suspect that profile is only looking at the memory from the point of 
view of the OS.  No block of memory can be released to the OS unless 
it's entirely freed.  My guess is that in the second case the variable i 
(or some other internal one relating to the loop) is in the same block 
with one of those lists.  The point is that CPython uses the C malloc() 
and free() functions, and they have their own limitations.  Most of the 
time when free() is called, the memory is NOT released to the OS, but is 
still made available within Python for future use.


-- 
DaveA


From maarten.sneep at knmi.nl  Fri May  3 11:20:27 2013
From: maarten.sneep at knmi.nl (Maarten)
Date: Fri, 3 May 2013 08:20:27 -0700 (PDT)
Subject: Trying to understand the memory occupation of big lists
In-Reply-To: <e09e5cf1-4df5-4e77-9108-32bc3a1ae07d@googlegroups.com>
References: <e09e5cf1-4df5-4e77-9108-32bc3a1ae07d@googlegroups.com>
Message-ID: <216083a7-fb00-471e-b123-af19ea6a7aef@googlegroups.com>

I made a few changes:

import gc
from memory_profiler import profile

@profile
def test1():
    a = [0] * 1024**2
    del a
    a = [0] * 1024**2
    del a
    a = [0] * 1024**2
    del a
    a = [0] * 1024**2
    del a
    a = [0] * 1024**2
    del a
    a = [0] * 1024**2
    del a
    a = [0] * 1024**2
    del a
    a = [0] * 1024**2
    del a
    a = [0] * 1024**2
    del a
    a = [0] * 1024**2
    del a
    gc.collect()  # nothing change if I comment this


@profile
def test2():
    for i in range(10):
        a = [0] * 1024**2
        del a
    del i
    gc.collect()  # nothing change if I comment this


test1()
test2() 

# end of code

Output:

Filename: profile.py

Line #    Mem usage    Increment   Line Contents
================================================
     5                             @profile
     6     8.688 MB     0.000 MB   def test1():
     7    16.691 MB     8.004 MB       a = [0] * 1024**2
     8     8.688 MB    -8.004 MB       del a
     9    16.680 MB     7.992 MB       a = [0] * 1024**2
    10    16.680 MB     0.000 MB       del a
    11    16.680 MB     0.000 MB       a = [0] * 1024**2
    12    16.680 MB     0.000 MB       del a
    13    16.680 MB     0.000 MB       a = [0] * 1024**2
    14    16.680 MB     0.000 MB       del a
    15    16.680 MB     0.000 MB       a = [0] * 1024**2
    16    16.680 MB     0.000 MB       del a
    17    16.680 MB     0.000 MB       a = [0] * 1024**2
    18    16.680 MB     0.000 MB       del a
    19    16.680 MB     0.000 MB       a = [0] * 1024**2
    20    16.680 MB     0.000 MB       del a
    21    16.680 MB     0.000 MB       a = [0] * 1024**2
    22    16.680 MB     0.000 MB       del a
    23    16.680 MB     0.000 MB       a = [0] * 1024**2
    24    16.680 MB     0.000 MB       del a
    25    16.680 MB     0.000 MB       a = [0] * 1024**2
    26    16.680 MB     0.000 MB       del a
    27    16.680 MB     0.000 MB       gc.collect()  # nothing change if I comment this


Filename: profile.py

Line #    Mem usage    Increment   Line Contents
================================================
    30                             @profile
    31    16.691 MB     0.000 MB   def test2():
    32    16.691 MB     0.000 MB       for i in range(10):
    33    16.691 MB     0.000 MB           a = [0] * 1024**2
    34    16.691 MB     0.000 MB           del a
    35    16.691 MB     0.000 MB       del i
    36    16.691 MB     0.000 MB       gc.collect()  # nothing change if I comment this

If I make the two functions identical, the behave the same.

Maarten


From alec.taylor6 at gmail.com  Fri May  3 10:22:53 2013
From: alec.taylor6 at gmail.com (Alec Taylor)
Date: Sat, 4 May 2013 00:22:53 +1000
Subject: Highest performance Python framework for API exposure?
Message-ID: <CAO+9iGdq9J6-pR6t0btE9=-2BVwUOVMP=ZuKjZbNjnFp7JoxuA@mail.gmail.com>

Which Python framework has benchmarked the highest?

I am looking for a solution to initially run on Heroku or OpenShift;
but eventually run on a pure IaaS.

Will expose the interfaces RESTfully as JSON, purposed to act as the
"glue" between the endpoints, databases (incl. caches) and queues.

An additional requirement is support for serving static, downloadable
content efficiently.

Currently looking at Falcon, Bottle and Werkzeug.

Suggestions are greatly appreciated.

Thanks,

Alec Taylor


From roy at panix.com  Fri May  3 20:18:49 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 03 May 2013 20:18:49 -0400
Subject: Highest performance Python framework for API exposure?
References: <mailman.1269.1367590981.3114.python-list@python.org>
Message-ID: <roy-4B8DD5.20184903052013@news.panix.com>

In article <mailman.1269.1367590981.3114.python-list at python.org>,
 Alec Taylor <alec.taylor6 at gmail.com> wrote:

> Which Python framework has benchmarked the highest?
> 
> I am looking for a solution to initially run on Heroku or OpenShift;
> but eventually run on a pure IaaS.
> 
> Will expose the interfaces RESTfully as JSON, purposed to act as the
> "glue" between the endpoints, databases (incl. caches) and queues.

Based on my experience, it doesn't matter what framework you use.  All 
that's going to matter is how fast you can pump data in and out of your 
database.  The overhead added by the Python front-end probably won't be 
significant.

Pick a framework that you find easy to use and don't sweat it.  Invest 
your time worrying about your database.

> An additional requirement is support for serving static, downloadable
> content efficiently.

You don't want to do that with Python.  You want to do that with 
something that's optimized for serving static content (such as nginx).


From ryankoch38 at gmail.com  Fri May  3 13:18:58 2013
From: ryankoch38 at gmail.com (ryankoch38 at gmail.com)
Date: Fri, 3 May 2013 10:18:58 -0700 (PDT)
Subject: First python program, syntax error in while loop
Message-ID: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>

title = "Guess my number game:"
print title.title()
raw_input("Press any key to continue..")

import random

tries = 0
number = random.randrange(99) + 1
guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :")

while (guess != number):
if (guess > number):
    number = int(raw_input("Sorry, my number is lower than that! \n Try again:")
   tries += 1
else if (guess < number):
    number = int(raw_input("Sorry, my number is higher than that! \n Try again:")
    tries += 1
print "Congratulations, you guessed my number! \n And it only took you" tries "tries!"

raw_input("\n\n Press any key to exit..")

## what is wrong with this script? I'm just trying to understand while loops and ## this is not a real project :P


From kwpolska at gmail.com  Fri May  3 13:26:46 2013
From: kwpolska at gmail.com (=?UTF-8?B?Q2hyaXMg4oCcS3dwb2xza2HigJ0gV2Fycmljaw==?=)
Date: Fri, 3 May 2013 19:26:46 +0200
Subject: First python program, syntax error in while loop
In-Reply-To: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
Message-ID: <CAMw+j7Jkcp0_tvFypCf5b1bKOfze0gYsuadbPOCGeFP5eGjGrQ@mail.gmail.com>

On Fri, May 3, 2013 at 7:18 PM,  <ryankoch38 at gmail.com> wrote:
> title = "Guess my number game:"
> print title.title()
> raw_input("Press any key to continue..")
>
> import random
>
> tries = 0
> number = random.randrange(99) + 1
> guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :")
>
> while (guess != number):
> if (guess > number):
>     number = int(raw_input("Sorry, my number is lower than that! \n Try again:")
>    tries += 1
> else if (guess < number):
>     number = int(raw_input("Sorry, my number is higher than that! \n Try again:")
>     tries += 1
> print "Congratulations, you guessed my number! \n And it only took you" tries "tries!"
>
> raw_input("\n\n Press any key to exit..")
>
> ## what is wrong with this script? I'm just trying to understand while loops and ## this is not a real project :P
> --
> http://mail.python.org/mailman/listinfo/python-list

1. post full tracebacks.
2. The contents of your while loop must be indented, just like the
contents of the if/else if statement you have there.  So, four spaces
before the 'if', 'else if' and 'print' lines; eight before 'number'
and 'tries' lines.

--
Kwpolska <http://kwpolska.tk> | GPG KEY: 5EAAEA16
stop html mail                | always bottom-post
http://asciiribbon.org        | http://caliburn.nl/topposting.html


From gordon at panix.com  Fri May  3 13:27:05 2013
From: gordon at panix.com (John Gordon)
Date: Fri, 3 May 2013 17:27:05 +0000 (UTC)
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
Message-ID: <km0s19$q07$1@reader1.panix.com>

In <24c5856e-a30a-41bd-aa4a-0e594734e1f8 at googlegroups.com> ryankoch38 at gmail.com writes:

> title = "Guess my number game:"
> print title.title()
> raw_input("Press any key to continue..")

> import random

> tries = 0
> number = random.randrange(99) + 1
> guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :")

> while (guess != number):
> if (guess > number):
>     number = int(raw_input("Sorry, my number is lower than that! \n Try again:")
>    tries += 1
> else if (guess < number):
>     number = int(raw_input("Sorry, my number is higher than that! \n Try again:")
>     tries += 1
> print "Congratulations, you guessed my number! \n And it only took you" tries "tries!"

> raw_input("\n\n Press any key to exit..")

> ## what is wrong with this script? I'm just trying to understand while loops and ## this is not a real project :P

You're missing a second closing parentheses on the line where the user
inputs their guess.

Also, you need to indent the 'if' statement underneath the while loop.

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From python at mrabarnett.plus.com  Fri May  3 13:36:52 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 03 May 2013 18:36:52 +0100
Subject: First python program, syntax error in while loop
In-Reply-To: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
Message-ID: <5183F5B4.5030801@mrabarnett.plus.com>

On 03/05/2013 18:18, ryankoch38 at gmail.com wrote:
> title = "Guess my number game:"
> print title.title()
> raw_input("Press any key to continue..")
>
> import random
>
> tries = 0
> number = random.randrange(99) + 1
> guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :")
>
> while (guess != number):
> if (guess > number):
>      number = int(raw_input("Sorry, my number is lower than that! \n Try again:")
>     tries += 1
> else if (guess < number):
>      number = int(raw_input("Sorry, my number is higher than that! \n Try again:")
>      tries += 1
> print "Congratulations, you guessed my number! \n And it only took you" tries "tries!"
>
> raw_input("\n\n Press any key to exit..")
>
> ## what is wrong with this script? I'm just trying to understand while loops and ## this is not a real project :P
>
Indentation in important in Python.

Also, "else if" should be "elif", and you ask for a guess only once.


title = "Guess my number game:"
print title.title()
raw_input("Press any key to continue..")

import random

tries = 0
number = random.randrange(99) + 1

# Ask for first guess.
guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :")

while guess != number:
     if guess > number:
         number = int(raw_input("Sorry, my number is lower than that! \n 
Try again:")
         tries += 1
     elif guess < number:
         number = int(raw_input("Sorry, my number is higher than that! 
\n Try again:")
         tries += 1

     # Ask for next guess.
     guess = int(raw_input("Guess my number! Secret - It is between 1 
and 100 :")

print "Congratulations, you guessed my number! \n And it only took you" 
tries "tries!"

raw_input("\n\n Press any key to exit..")




From zachary.ware+pylist at gmail.com  Fri May  3 13:37:39 2013
From: zachary.ware+pylist at gmail.com (Zachary Ware)
Date: Fri, 3 May 2013 12:37:39 -0500
Subject: First python program, syntax error in while loop
In-Reply-To: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
Message-ID: <CAKJDb-OzQ6cH_9Lek-ouUn814e=kk+t7O3jdLEw6ythkLo--rg@mail.gmail.com>

On Fri, May 3, 2013 at 12:18 PM,  <ryankoch38 at gmail.com> wrote:
> title = "Guess my number game:"
> print title.title()
> raw_input("Press any key to continue..")
>
> import random
>
> tries = 0
> number = random.randrange(99) + 1
> guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :")

First up, there's a missing ) on each call to int(), which is causing
the syntax error you see.   The error points at "while" because
"while" doesn't make sense in the call to int().

>
> while (guess != number):
> if (guess > number):

After fixing the error above, you'll have another one here: you
haven't indented the block to be executed in the while loop.
Indentation is important in Python, it delimits code blocks and makes
things more readable for people.

>     number = int(raw_input("Sorry, my number is lower than that! \n Try again:")
>    tries += 1

There's also another indentation error here: everything in the same
block has to be indented to the same level.

> else if (guess < number):
>     number = int(raw_input("Sorry, my number is higher than that! \n Try again:")
>     tries += 1
> print "Congratulations, you guessed my number! \n And it only took you" tries "tries!"

And here will be another syntax error: you have to separate your
arguments to 'print' with commas.

>
> raw_input("\n\n Press any key to exit..")
>
> ## what is wrong with this script? I'm just trying to understand while loops and ## this is not a real project :P


Once you have those errors fixed, I'll bet I can guess your number on
the second try every time.  I'll let you figure out why yourself,
though ;).


From gordon at panix.com  Fri May  3 13:37:56 2013
From: gordon at panix.com (John Gordon)
Date: Fri, 3 May 2013 17:37:56 +0000 (UTC)
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<mailman.1272.1367602030.3114.python-list@python.org>
Message-ID: <km0slk$la4$1@reader1.panix.com>

In <mailman.1272.1367602030.3114.python-list at python.org> =?UTF-8?B?Q2hyaXMg4oCcS3dwb2xza2HigJ0gV2Fycmljaw==?= <kwpolska at gmail.com> writes:

> 1. post full tracebacks.

I almost responded with the same advice, but in this case the full
traceback doesn't really tell us anything more:

      File "foo.py", line 11
        while guess != number:
            ^
    SyntaxError: invalid syntax

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From ryankoch38 at gmail.com  Fri May  3 13:57:00 2013
From: ryankoch38 at gmail.com (ryankoch38 at gmail.com)
Date: Fri, 3 May 2013 10:57:00 -0700 (PDT)
Subject: First python program, syntax error in while loop
In-Reply-To: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
Message-ID: <02b65e11-89c6-4639-9d93-27e1f90eed66@googlegroups.com>

Okay, thank you very much for the timely replies, heres what i have now:

title = "Guess my number game:"
print title.title()
raw_input("Press any key to continue..")

import random

number = random.randrange(99) + 1
tries = 0
guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :"))

while (guess != number):
    if (guess > number):
        number = int(raw_input("Sorry, my number is lower than that! \n Try again:"))
        tries += 1
    else:
        number = int(raw_input("Sorry, my number is higher than that! \n Try again:"))
        tries += 1
        
        print "good job, you won!"
        


raw_input("\n\n Press any key to exit..")


## it seems to stick with "higher" or "lower" after my first guess, whichever it 
## is


From gordon at panix.com  Fri May  3 14:21:50 2013
From: gordon at panix.com (John Gordon)
Date: Fri, 3 May 2013 18:21:50 +0000 (UTC)
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<02b65e11-89c6-4639-9d93-27e1f90eed66@googlegroups.com>
Message-ID: <km0v7u$op4$1@reader1.panix.com>

In <02b65e11-89c6-4639-9d93-27e1f90eed66 at googlegroups.com> ryankoch38 at gmail.com writes:

> Okay, thank you very much for the timely replies, heres what i have now:

> title = "Guess my number game:"
> print title.title()
> raw_input("Press any key to continue..")

> import random

> number = random.randrange(99) + 1
> tries = 0
> guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :"))

> while (guess != number):
>     if (guess > number):
>         number = int(raw_input("Sorry, my number is lower than that! \n Try again:"))
>         tries += 1
>     else:
>         number = int(raw_input("Sorry, my number is higher than that! \n Try again:"))
>         tries += 1
>         
>         print "good job, you won!"
>         


> raw_input("\n\n Press any key to exit..")


> ## it seems to stick with "higher" or "lower" after my first guess, whichever it 
> ## is

When the user re-enters their guess in the while loop, you're assigning
the input to "number" instead of "guess".

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From ryankoch38 at gmail.com  Fri May  3 14:34:42 2013
From: ryankoch38 at gmail.com (ryankoch38 at gmail.com)
Date: Fri, 3 May 2013 11:34:42 -0700 (PDT)
Subject: First python program, syntax error in while loop
In-Reply-To: <km0v7u$op4$1@reader1.panix.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<02b65e11-89c6-4639-9d93-27e1f90eed66@googlegroups.com>
	<km0v7u$op4$1@reader1.panix.com>
Message-ID: <324dbba9-42d5-40c7-959d-c00e914925b6@googlegroups.com>

Oh wow I can't believed I derped that hard!!!!
Thanks Lol.


From ryankoch38 at gmail.com  Fri May  3 15:52:14 2013
From: ryankoch38 at gmail.com (ryankoch38 at gmail.com)
Date: Fri, 3 May 2013 12:52:14 -0700 (PDT)
Subject: First python program, syntax error in while loop
In-Reply-To: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
Message-ID: <af59d0cb-5ca3-42ab-83c3-2be84da8015d@googlegroups.com>

I've got it working! I'm really enjoying python :) But now i'd like to make it break out of the while loop when the user guesses more than 5 numbers and fails..

title = "Guess my number game:" 
print title.title() 
raw_input("Press any key to continue..") 

import random 

number = random.randrange(99) + 1 
tries = 0 
guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :")) 

while (guess != number): 
    if (guess > number): 
        guess = int(raw_input("Sorry, my number is lower than that! \n Try again:")) 
        tries += 1 
    if (guess < number): 
        guess = int(raw_input("Sorry, my number is higher than that! \n Try again:")) 
        tries += 1
    if (tries > 5):
        print "Sorry, you lost!"
        break
    
    print "\nCongratulations! You guessed my number in", tries, "tries"


raw_input("\n\n Press any key to exit..") 

## this results in the congratulations printing after the second/third guess and ## continuing


From gordon at panix.com  Fri May  3 16:04:00 2013
From: gordon at panix.com (John Gordon)
Date: Fri, 3 May 2013 20:04:00 +0000 (UTC)
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<af59d0cb-5ca3-42ab-83c3-2be84da8015d@googlegroups.com>
Message-ID: <km157f$7vo$1@reader1.panix.com>

In <af59d0cb-5ca3-42ab-83c3-2be84da8015d at googlegroups.com> ryankoch38 at gmail.com writes:

> I've got it working! I'm really enjoying python :) But now i'd like to make it break out of the while loop when the user guesses more than 5 numbers and fails

The "Congratulations" message is inside the while loop; that's why it
always prints.

To break after five guesses, you could change the while loop to this:

    while (guess != number) and (tries < 5): 

And then after the while loop, put this if statement:

    if (tries < 5):
        print "\nCongratulations! You guessed my number in", tries, "tries"

    else:
        print "Sorry, you lost!"

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From ryankoch38 at gmail.com  Fri May  3 16:15:50 2013
From: ryankoch38 at gmail.com (ryankoch38 at gmail.com)
Date: Fri, 3 May 2013 13:15:50 -0700 (PDT)
Subject: First python program, syntax error in while loop
In-Reply-To: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
Message-ID: <163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>

Thank you! It's 100% functional now, here's the final project:

title = "Guess my number game:" 
print title.title() 
raw_input("Press any key to continue..") 

import random 

number = random.randrange(99) + 1 
tries = 0 
guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :")) 

while (guess != number) and (tries <5): 
    if (guess > number): 
        guess = int(raw_input("Sorry, my number is lower than that! \n Try again:")) 
        tries += 1 
    if (guess < number): 
        guess = int(raw_input("Sorry, my number is higher than that! \n Try again:")) 
        tries += 1 
        
if (tries <5):
    print "\nCongratulations! You guessed my number in", tries, "tries"
else:
    print "\nSorry, you took too many tries to guess my number!"


raw_input("\n\n Press any key to exit..")

## Maybe now I can work on a useful project


From neilc at norwich.edu  Fri May  3 16:30:23 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 3 May 2013 20:30:23 GMT
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
Message-ID: <auil2vFijo4U1@mid.individual.net>

On 2013-05-03, ryankoch38 at gmail.com <ryankoch38 at gmail.com> wrote:
> Thank you! It's 100% functional now, here's the final project:
>
> title = "Guess my number game:" 
> print title.title() 
> raw_input("Press any key to continue..") 
>
> import random 
>
> number = random.randrange(99) + 1 
> tries = 0 
> guess = int(raw_input("Guess my number! Secret - It is between 1 and 100 :")) 
>
> while (guess != number) and (tries <5): 
>     [...]
>         
> if (tries <5):
>     print "\nCongratulations! You guessed my number in", tries, "tries"
> else:
>     print "\nSorry, you took too many tries to guess my number!"
> raw_input("\n\n Press any key to exit..")
>
> ## Maybe now I can work on a useful project

Not quite yet. Players who guess correctly on the fifth try don't
get credit.

-- 
Neil Cerutti


From gordon at panix.com  Fri May  3 16:38:47 2013
From: gordon at panix.com (John Gordon)
Date: Fri, 3 May 2013 20:38:47 +0000 (UTC)
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net>
Message-ID: <km178n$5mn$1@reader1.panix.com>

In <auil2vFijo4U1 at mid.individual.net> Neil Cerutti <neilc at norwich.edu> writes:

> Not quite yet. Players who guess correctly on the fifth try don't
> get credit.

Are you sure?  tries is initialized to zero and isn't incremented for the
initial guess.

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From neilc at norwich.edu  Mon May  6 08:06:36 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 6 May 2013 12:06:36 GMT
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net> <km178n$5mn$1@reader1.panix.com>
Message-ID: <aupkmcF2mv6U4@mid.individual.net>

On 2013-05-03, John Gordon <gordon at panix.com> wrote:
> In <auil2vFijo4U1 at mid.individual.net> Neil Cerutti <neilc at norwich.edu> writes:
>
>> Not quite yet. Players who guess correctly on the fifth try don't
>> get credit.
>
> Are you sure?  tries is initialized to zero and isn't
> incremented for the initial guess.

while (number != guess) and (tries < 5):

Is the condition that concludes the game.

After the game, you are told you lost if tries is not less than
five, regardless of if number == guess.

-- 
Neil Cerutti


From breamoreboy at yahoo.co.uk  Mon May  6 08:37:48 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 06 May 2013 13:37:48 +0100
Subject: First python program, syntax error in while loop
In-Reply-To: <aupkmcF2mv6U4@mid.individual.net>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net> <km178n$5mn$1@reader1.panix.com>
	<aupkmcF2mv6U4@mid.individual.net>
Message-ID: <km886n$vqo$1@ger.gmane.org>

On 06/05/2013 13:06, Neil Cerutti wrote:
> On 2013-05-03, John Gordon <gordon at panix.com> wrote:
>> In <auil2vFijo4U1 at mid.individual.net> Neil Cerutti <neilc at norwich.edu> writes:
>>
>>> Not quite yet. Players who guess correctly on the fifth try don't
>>> get credit.
>>
>> Are you sure?  tries is initialized to zero and isn't
>> incremented for the initial guess.
>
> while (number != guess) and (tries < 5):
>
> Is the condition that concludes the game.
>
> After the game, you are told you lost if tries is not less than
> five, regardless of if number == guess.
>

One of these days I'll work out why some people insist on using 
superfluous parentheses in Python code.  Could it be that they enjoy 
exercising their fingers by reaching for the shift key in conjunction 
with the 9 or 0 key?

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From neilc at norwich.edu  Mon May  6 09:07:20 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 6 May 2013 13:07:20 GMT
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net> <km178n$5mn$1@reader1.panix.com>
	<aupkmcF2mv6U4@mid.individual.net>
	<mailman.1360.1367843880.3114.python-list@python.org>
Message-ID: <aupo88F2mv6U5@mid.individual.net>

On 2013-05-06, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 06/05/2013 13:06, Neil Cerutti wrote:
>> On 2013-05-03, John Gordon <gordon at panix.com> wrote:
>>> In <auil2vFijo4U1 at mid.individual.net> Neil Cerutti <neilc at norwich.edu> writes:
>>>
>>>> Not quite yet. Players who guess correctly on the fifth try don't
>>>> get credit.
>>>
>>> Are you sure?  tries is initialized to zero and isn't
>>> incremented for the initial guess.
>>
>> while (number != guess) and (tries < 5):
>>
>> Is the condition that concludes the game.
>>
>> After the game, you are told you lost if tries is not less than
>> five, regardless of if number == guess.
>
> One of these days I'll work out why some people insist on using
> superfluous parentheses in Python code.  Could it be that they
> enjoy exercising their fingers by reaching for the shift key in
> conjunction with the 9 or 0 key?

Superflous parenthesis are sometimes a nice aid to comprehension.

I don't know about the above case, though. I don't think it hurts
anything, but it doesn't add much.

-- 
Neil Cerutti


From roy at panix.com  Mon May  6 09:08:44 2013
From: roy at panix.com (Roy Smith)
Date: Mon, 06 May 2013 09:08:44 -0400
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net> <km178n$5mn$1@reader1.panix.com>
	<aupkmcF2mv6U4@mid.individual.net>
	<mailman.1360.1367843880.3114.python-list@python.org>
Message-ID: <roy-76F87B.09084406052013@news.panix.com>

In article <mailman.1360.1367843880.3114.python-list at python.org>,
 Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:

> > while (number != guess) and (tries < 5):
> 
> One of these days I'll work out why some people insist on using 
> superfluous parentheses in Python code.  Could it be that they enjoy 
> exercising their fingers by reaching for the shift key in conjunction 
> with the 9 or 0 key?

There's lots of reasons.  Some valid, some not.

Lets dispense with the invalid reason first.  They've come from 
C/C++/Java/whatever and are used to typing parens around the conditions 
for if/for/while statements.  To them, I say, "Stop trying to write 
FORTRAN code in languages that aren't FORTRAN".

In this case, however, I have no problem with the extra parens.  Look at 
these two statements:

>> while (number != guess) and (tries < 5):
>> while number != guess and tries < 5:

They have the same meaning.  To correctly interpret the second one, you 
need to know that != and < bind tighter than "and". One could say that 
you should know that, and maybe you would be right.

On the other hand, I've long since given up trying to remember operator 
precedence in various languages.  If I ever have even the slightest 
doubt, I just go ahead and put in the extra parens.  It takes another 
few ms to type, and it removes all ambiguity (for both me, and every 
future person who has to read my code).  And, every once in a while, it 
keeps me from writing a subtle and hard-to-find bug because the 
precedence rules I was sure I had remembered correctly turned out to be 
wrong for the language I happened to be typing that day.

BTW, in C, I used to write:

return (foo)

for years until somebody pointed out to me that

return foo

works.  I just assumed that if I had to write:

if (foo)
while (foo)
for (foo; bar; baz)

then

return (foo)

made sense too.


From rosuav at gmail.com  Mon May  6 09:37:56 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 23:37:56 +1000
Subject: First python program, syntax error in while loop
In-Reply-To: <roy-76F87B.09084406052013@news.panix.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net> <km178n$5mn$1@reader1.panix.com>
	<aupkmcF2mv6U4@mid.individual.net>
	<mailman.1360.1367843880.3114.python-list@python.org>
	<roy-76F87B.09084406052013@news.panix.com>
Message-ID: <CAPTjJmoTiu22o+AEVwAnUdVt_EQVO77NpvgX1xLiAwtrme-3NQ@mail.gmail.com>

On Mon, May 6, 2013 at 11:08 PM, Roy Smith <roy at panix.com> wrote:
> On the other hand, I've long since given up trying to remember operator
> precedence in various languages.  If I ever have even the slightest
> doubt, I just go ahead and put in the extra parens.

If I ever have even the slightest doubt, I just go ahead and type
"<language> operator precedence" into a web search and check it :)
Aside from utter insanity like PHP's ternary operator being wrongly
associative, that covers pretty much everything.

ChrisA


From rustompmody at gmail.com  Mon May  6 09:36:31 2013
From: rustompmody at gmail.com (rusi)
Date: Mon, 6 May 2013 06:36:31 -0700 (PDT)
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net>
	<km178n$5mn$1@reader1.panix.com> <aupkmcF2mv6U4@mid.individual.net>
	<mailman.1360.1367843880.3114.python-list@python.org>
	<roy-76F87B.09084406052013@news.panix.com>
Message-ID: <bfd67f87-4ef9-4159-9a41-0fbcdd284eb7@n5g2000pbg.googlegroups.com>

On May 6, 6:08?pm, Roy Smith <r... at panix.com> wrote:

> BTW, in C, I used to write:
>
> return (foo)
>
> for years until somebody pointed out to me that
>
> return foo
>
> works. ?I just assumed that if I had to write:
>
> if (foo)
> while (foo)
> for (foo; bar; baz)
>
> then
>
> return (foo)
>
> made sense too.

I guess its because K&R always show their examples with
return (expr);
and so we all assume its the propah way


From roy at panix.com  Mon May  6 11:31:54 2013
From: roy at panix.com (Roy Smith)
Date: 6 May 2013 11:31:54 -0400
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<mailman.1360.1367843880.3114.python-list@python.org>
	<roy-76F87B.09084406052013@news.panix.com>
	<mailman.1361.1367847484.3114.python-list@python.org>
Message-ID: <km8ida$dgh$1@panix2.panix.com>

In article <mailman.1361.1367847484.3114.python-list at python.org>,
Chris Angelico  <rosuav at gmail.com> wrote:
>On Mon, May 6, 2013 at 11:08 PM, Roy Smith <roy at panix.com> wrote:
>> On the other hand, I've long since given up trying to remember operator
>> precedence in various languages.  If I ever have even the slightest
>> doubt, I just go ahead and put in the extra parens.
>
>If I ever have even the slightest doubt, I just go ahead and type
>"<language> operator precedence" into a web search and check it :)

Well, that solves the problem once, and it solves it for me.  I figure
if I'm not 100% sure, then maybe other people aren't 100% sure either,
and my adding the extra parens helps them too.


From tjreedy at udel.edu  Mon May  6 16:11:35 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Mon, 06 May 2013 16:11:35 -0400
Subject: First python program, syntax error in while loop
In-Reply-To: <km8ida$dgh$1@panix2.panix.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<mailman.1360.1367843880.3114.python-list@python.org>
	<roy-76F87B.09084406052013@news.panix.com>
	<mailman.1361.1367847484.3114.python-list@python.org>
	<km8ida$dgh$1@panix2.panix.com>
Message-ID: <km92ph$8gs$1@ger.gmane.org>

On 5/6/2013 11:31 AM, Roy Smith wrote:
> In article <mailman.1361.1367847484.3114.python-list at python.org>,
> Chris Angelico  <rosuav at gmail.com> wrote:
>> On Mon, May 6, 2013 at 11:08 PM, Roy Smith <roy at panix.com> wrote:
>>> On the other hand, I've long since given up trying to remember operator
>>> precedence in various languages.  If I ever have even the slightest
>>> doubt, I just go ahead and put in the extra parens.
>>
>> If I ever have even the slightest doubt, I just go ahead and type
>> "<language> operator precedence" into a web search and check it :)
>
> Well, that solves the problem once, and it solves it for me.  I figure
> if I'm not 100% sure, then maybe other people aren't 100% sure either,
> and my adding the extra parens helps them too.

If you keep the Python docs handy, on or off line, the Language manual 
Expressions chapter ends with this single page (but better formatted as 
a table than here). But I sometimes add parens for quickness or readability.

6.15. Operator precedence
The following table summarizes the operator precedences in Python, from 
lowest precedence (least binding) to highest precedence (most binding). 
Operators in the same box have the same precedence. Unless the syntax is 
explicitly given, operators are binary. Operators in the same box group 
left to right (except for comparisons, including tests, which all have 
the same precedence and chain from left to right ? see section 
Comparisons ? and exponentiation, which groups from right to left).

Operator Description
lambda Lambda expression
if ? else Conditional expression
or Boolean OR
and Boolean AND
not x Boolean NOT
in, not in, is, is not, <, <=, >, >=, !=, == Comparisons, including 
membership tests and identity tests,
| Bitwise OR
^ Bitwise XOR
& Bitwise AND
<<, >> Shifts
+, - Addition and subtraction
*, /, //, % Multiplication, division, remainder [5]
+x, -x, ~x Positive, negative, bitwise NOT
** Exponentiation [6]
x[index], x[index:index], x(arguments...), x.attribute Subscription, 
slicing, call, attribute reference
(expressions...), [expressions...], {key: value...}, {expressions...} 
Binding or tuple display, list display, dictionary display, set display

Footnotes

[1] While abs(x%y) < abs(y) is true mathematically, for floats it may 
not be true numerically due to roundoff. For example, and assuming a 
platform on which a Python float is an IEEE 754 double-precision number, 
in order that -1e-100 % 1e100 have the same sign as 1e100, the computed 
result is -1e-100 + 1e100, which is numerically exactly equal to 1e100. 
The function math.fmod() returns a result whose sign matches the sign of 
the first argument instead, and so returns -1e-100 in this case. Which 
approach is more appropriate depends on the application.
[2] If x is very close to an exact integer multiple of y, it?s possible 
for x//y to be one larger than (x-x%y)//y due to rounding. In such 
cases, Python returns the latter result, in order to preserve that 
divmod(x,y)[0] * y + x % y be very close to x.
[3] While comparisons between strings make sense at the byte level, they 
may be counter-intuitive to users. For example, the strings "\u00C7" and 
"\u0327\u0043" compare differently, even though they both represent the 
same unicode character (LATIN CAPITAL LETTER C WITH CEDILLA). To compare 
strings in a human recognizable way, compare using unicodedata.normalize().
[4] Due to automatic garbage-collection, free lists, and the dynamic 
nature of descriptors, you may notice seemingly unusual behaviour in 
certain uses of the is operator, like those involving comparisons 
between instance methods, or constants. Check their documentation for 
more info.
[5] The % operator is also used for string formatting; the same 
precedence applies.
[6] The power operator ** binds less tightly than an arithmetic or 
bitwise unary operator on its right, that is, 2**-1 is 0.5.





From rosuav at gmail.com  Mon May  6 17:50:59 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 7 May 2013 07:50:59 +1000
Subject: First python program, syntax error in while loop
In-Reply-To: <km92ph$8gs$1@ger.gmane.org>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<mailman.1360.1367843880.3114.python-list@python.org>
	<roy-76F87B.09084406052013@news.panix.com>
	<mailman.1361.1367847484.3114.python-list@python.org>
	<km8ida$dgh$1@panix2.panix.com> <km92ph$8gs$1@ger.gmane.org>
Message-ID: <CAPTjJmoAUV9wo3fv=293Yn+QLCj2tTu08jyh+w+ZM6YB4EVyGA@mail.gmail.com>

On Tue, May 7, 2013 at 6:11 AM, Terry Jan Reedy <tjreedy at udel.edu> wrote:
> On 5/6/2013 11:31 AM, Roy Smith wrote:
>>
>> In article <mailman.1361.1367847484.3114.python-list at python.org>,
>> Chris Angelico  <rosuav at gmail.com> wrote:
>>> If I ever have even the slightest doubt, I just go ahead and type
>>> "<language> operator precedence" into a web search and check it :)
>>
>>
>> Well, that solves the problem once, and it solves it for me.  I figure
>> if I'm not 100% sure, then maybe other people aren't 100% sure either,
>> and my adding the extra parens helps them too.
>
>
> If you keep the Python docs handy, on or off line, the Language manual
> Expressions chapter ends with this single page (but better formatted as a
> table than here). But I sometimes add parens for quickness or readability.
>
> or Boolean OR
> and Boolean AND

Actually, this is one exception. I tend to parenthesize any case where
there's a complex set of conditions and mixed AND and OR operations.
Part of the reason for this is that any expression that can be
affected by the precedence of and and or will most likely be fairly
long and/or complex anyway, so a few extra parens won't hurt.

ChrisA


From wuwei23 at gmail.com  Mon May  6 20:17:01 2013
From: wuwei23 at gmail.com (alex23)
Date: Mon, 6 May 2013 17:17:01 -0700 (PDT)
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net>
	<km178n$5mn$1@reader1.panix.com> <aupkmcF2mv6U4@mid.individual.net>
	<mailman.1360.1367843880.3114.python-list@python.org>
Message-ID: <b00aecc2-149d-4ba8-a096-267dc881d0a1@n5g2000pbg.googlegroups.com>

On May 6, 10:37?pm, Mark Lawrence <breamore... at yahoo.co.uk> wrote:
> One of these days I'll work out why some people insist on using
> superfluous parentheses in Python code. ?Could it be that they enjoy
> exercising their fingers by reaching for the shift key in conjunction
> with the 9 or 0 key?

One of these days I'll work out why some programmers consider typing
to be "effort".


From roy at panix.com  Mon May  6 20:18:59 2013
From: roy at panix.com (Roy Smith)
Date: Mon, 06 May 2013 20:18:59 -0400
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net> <km178n$5mn$1@reader1.panix.com>
	<aupkmcF2mv6U4@mid.individual.net>
	<mailman.1360.1367843880.3114.python-list@python.org>
	<b00aecc2-149d-4ba8-a096-267dc881d0a1@n5g2000pbg.googlegroups.com>
Message-ID: <roy-3F31B3.20185906052013@news.panix.com>

In article 
<b00aecc2-149d-4ba8-a096-267dc881d0a1 at n5g2000pbg.googlegroups.com>,
 alex23 <wuwei23 at gmail.com> wrote:

> On May 6, 10:37?pm, Mark Lawrence <breamore... at yahoo.co.uk> wrote:
> > One of these days I'll work out why some people insist on using
> > superfluous parentheses in Python code. ?Could it be that they enjoy
> > exercising their fingers by reaching for the shift key in conjunction
> > with the 9 or 0 key?
> 
> One of these days I'll work out why some programmers consider typing
> to be "effort".

RSI.


From dan at tombstonezero.net  Tue May  7 01:03:22 2013
From: dan at tombstonezero.net (Dan Sommers)
Date: Tue, 07 May 2013 05:03:22 GMT
Subject: First python program, syntax error in while loop
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net> <km178n$5mn$1@reader1.panix.com>
	<aupkmcF2mv6U4@mid.individual.net>
	<mailman.1360.1367843880.3114.python-list@python.org>
	<b00aecc2-149d-4ba8-a096-267dc881d0a1@n5g2000pbg.googlegroups.com>
Message-ID: <uW%ht.43616$YR4.36568@newsfe28.iad>

On Mon, 06 May 2013 17:17:01 -0700, alex23 wrote:

> One of these days I'll work out why some programmers consider typing to
> be "effort".

An ironic comment from someone who goes by the moniker wu wei!  ;-)

The effort, of course, comes in determining what to type, and often how to
type less.


From breamoreboy at yahoo.co.uk  Tue May  7 02:10:28 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 07 May 2013 07:10:28 +0100
Subject: First python program, syntax error in while loop
In-Reply-To: <b00aecc2-149d-4ba8-a096-267dc881d0a1@n5g2000pbg.googlegroups.com>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net> <km178n$5mn$1@reader1.panix.com>
	<aupkmcF2mv6U4@mid.individual.net>
	<mailman.1360.1367843880.3114.python-list@python.org>
	<b00aecc2-149d-4ba8-a096-267dc881d0a1@n5g2000pbg.googlegroups.com>
Message-ID: <kma5sh$6qu$1@ger.gmane.org>

On 07/05/2013 01:17, alex23 wrote:
> On May 6, 10:37 pm, Mark Lawrence <breamore... at yahoo.co.uk> wrote:
>> One of these days I'll work out why some people insist on using
>> superfluous parentheses in Python code.  Could it be that they enjoy
>> exercising their fingers by reaching for the shift key in conjunction
>> with the 9 or 0 key?
>
> One of these days I'll work out why some programmers consider typing
> to be "effort".
>

I think it's very important to consider this aspect.  E.g. any one using 
dynamically typed languages has to put in more effort as they should be 
typing up their test code, whereas people using statically typed 
languages can simply head down to the pub once their code has compiled.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From rosuav at gmail.com  Tue May  7 05:19:49 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 7 May 2013 19:19:49 +1000
Subject: First python program, syntax error in while loop
In-Reply-To: <kma5sh$6qu$1@ger.gmane.org>
References: <24c5856e-a30a-41bd-aa4a-0e594734e1f8@googlegroups.com>
	<163bd508-f225-4b4d-8173-1e070c5d5aad@googlegroups.com>
	<auil2vFijo4U1@mid.individual.net> <km178n$5mn$1@reader1.panix.com>
	<aupkmcF2mv6U4@mid.individual.net>
	<mailman.1360.1367843880.3114.python-list@python.org>
	<b00aecc2-149d-4ba8-a096-267dc881d0a1@n5g2000pbg.googlegroups.com>
	<kma5sh$6qu$1@ger.gmane.org>
Message-ID: <CAPTjJmrE9jFnb6PrqSgyUJO4r9+gYiqEugYNtgvNZPk=YpoJtQ@mail.gmail.com>

On Tue, May 7, 2013 at 4:10 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 07/05/2013 01:17, alex23 wrote:
>>
>> On May 6, 10:37 pm, Mark Lawrence <breamore... at yahoo.co.uk> wrote:
>>>
>>> One of these days I'll work out why some people insist on using
>>> superfluous parentheses in Python code.  Could it be that they enjoy
>>> exercising their fingers by reaching for the shift key in conjunction
>>> with the 9 or 0 key?
>>
>>
>> One of these days I'll work out why some programmers consider typing
>> to be "effort".
>>
>
> I think it's very important to consider this aspect.  E.g. any one using
> dynamically typed languages has to put in more effort as they should be
> typing up their test code, whereas people using statically typed languages
> can simply head down to the pub once their code has compiled.

And those who are porting other people's code to a new platform have
weeks of work just to get ./configure to run, but after that it's
smooth...

Everything is variable.

ChrisA


From rosuav at gmail.com  Tue May  7 09:29:57 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 7 May 2013 23:29:57 +1000
Subject: First python program, syntax error in while loop
In-Reply-To: <CAM6w3no+sUrF+=jOOgr2SBpPQSZS4EQSLSF7LM19W14rAAPiUA@mail.gmail.com>
References: <CAM6w3no+sUrF+=jOOgr2SBpPQSZS4EQSLSF7LM19W14rAAPiUA@mail.gmail.com>
Message-ID: <CAPTjJmr1GKSn34K97gYJJ+CA-+-0T2amgJ5U9Mrvc1CwvPB5Fw@mail.gmail.com>

On Tue, May 7, 2013 at 10:44 PM, Ombongi Moraa Fe
<moraa.lovetakes2 at gmail.com> wrote:
> My first language was Pascal. It was at a time in 2005 when computers were
> finally becoming popular in Africa and our year was the first time a girls
> school from our Province did a computer coursework for National Exams. (That
> was such an achievement *sigh*)
>
> "The teacher said ... Good Programming Practice ... Use parentheses to
> format code.. or I will deduct a point from your work when I feel like it."
>
> Cant seem to let go of the behavior. I use parentheses in all languages.

Pretty much all such blanket advice is flawed. I cannot at present
think of any example of a "Good Programming Practice" suggestion that
doesn't have its exceptions and caveats. The only ones that don't are
the ones that get codified into language/syntax rules, and even there,
most of them have their detractors. Python's indentation rule is a
prime example; most people follow the advice to always indent blocks
of code, Python makes it mandatory, and some people hate Python for
it. (And yes, there have been times when I've deliberately misindented
a block of C code, because it made more logical sense that way. I can
quote examples if you like.)

The only principle that you should follow is: Think about what you're
doing. Everything else is an elaboration on that. [1]

ChrisA
[1] Matthew 22:37-40 :)


From info at wingware.com  Fri May  3 15:11:03 2013
From: info at wingware.com (Wingware)
Date: Fri, 03 May 2013 15:11:03 -0400
Subject: ANN: Wing IDE 4.1.13 released
Message-ID: <51840BC7.70301@wingware.com>

Hi,

Wingware has released version 4.1.13 of Wing IDE, our integrated development
environment designed specifically for the Python programming language.

Wing IDE provides a professional quality code editor with vi, emacs, and 
other
key bindings, auto-completion, call tips, refactoring, context-aware 
auto-editing,
a powerful graphical debugger, version control, unit testing, search, 
and many
other features.  For details see http://wingware.com/

This minor release includes:

* Sped up Search in Files, particularly when looking in Project Files
* Sped up project load
* Several auto-editing fixes
* Several VI mode fixes
* Correctly detect snippet context in files with tab indentation
* Fix goto-definition in the Debug Probe
* Added How-To with tips for using Wing IDE with GTK via PyGObject
* 14 other bug fixes and minor improvements

For a complete change log see 
http://wingware.com/pub/wingide/4.1.13/CHANGELOG.txt

Free trial: http://wingware.com/wingide/trial
Downloads: http://wingware.com/downloads
Feature matrix: http://wingware.com/wingide/features
More information: http://wingware.com/
Sales: http://wingware.com/store/purchase
Upgrades: https://wingware.com/store/upgrade

Questions?  Don't hesitate to email us at sales at wingware.com.

Thanks,

-- 

Stephan Deibel
Wingware | Python IDE
Advancing Software Development

www.wingware.com



From ethan at stoneleaf.us  Fri May  3 15:24:59 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Fri, 03 May 2013 12:24:59 -0700
Subject: ANN: Wing IDE 4.1.13 released
In-Reply-To: <51840BC7.70301@wingware.com>
References: <51840BC7.70301@wingware.com>
Message-ID: <51840F0B.2030500@stoneleaf.us>

I remember seeing one of the IDE's recently saying they had better support for dark color schemes.

Was it Wing, or does Wing support dark color schemes?  The main reason I stick with the older text editors is because I 
can have a black background -- looking at bright white screens all day kills my eyes.

--
~Ethan~


From hossamalagmy at gmail.com  Fri May  3 17:48:13 2013
From: hossamalagmy at gmail.com (23alagmy)
Date: Fri, 3 May 2013 14:48:13 -0700 (PDT)
Subject: https://www.facebook.com/pages/%D9%86%D8%AA%D8%A7%D8%A6%D8%AC-%D8%A7%D9%84%D8%A7%D9%85%D8%AA%D8%AD%D8%A7%D9%86%D8%A7%D8%AA-%D9%88%D8%A7%D9%84%D8%AC%D8%A7%D9%85%D8%B9%D8%A7%D8%AA-%D9%88%D8%A7%D8%AC%D8%AA%D9%85%D8%A7%D8%B9%D9%8A%D8%A7%D8%AA/29971916
Message-ID: <b222d382-e7b1-40a9-ab18-1c882db37a50@y14g2000vbk.googlegroups.com>

https://www.facebook.com/pages/%D9%86%D8%AA%D8%A7%D8%A6%D8%AC-%D8%A7%D9%84%D8%A7%D9%85%D8%AA%D8%AD%D8%A7%D9%86%D8%A7%D8%AA-%D9%88%D8%A7%D9%84%D8%AC%D8%A7%D9%85%D8%B9%D8%A7%D8%AA-%D9%88%D8%A7%D8%AC%D8%AA%D9%85%D8%A7%D8%B9%D9%8A%D8%A7%D8%AA/299719160065550?ref=hl


From agardner210 at gmail.com  Fri May  3 18:23:35 2013
From: agardner210 at gmail.com (Alex Gardner)
Date: Fri, 3 May 2013 15:23:35 -0700 (PDT)
Subject: Collision of Two Rect
Message-ID: <9083ecbc-5666-41aa-aacb-3f08f062feed@googlegroups.com>

When rect A collides with rect B they stick when I am wanting A to bounce off of B.  I have tried different methods, but none seem to work.  My source is here:  http://pastebin.com/CBYPcubL

The collision code itself is below:
------
# Bounce off of the paddle
if paddle_rect.colliderect(ball_rect):
    y_vel*=-1
    x_vel*=-1


From ian.g.kelly at gmail.com  Fri May  3 19:42:30 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 3 May 2013 17:42:30 -0600
Subject: Collision of Two Rect
In-Reply-To: <9083ecbc-5666-41aa-aacb-3f08f062feed@googlegroups.com>
References: <9083ecbc-5666-41aa-aacb-3f08f062feed@googlegroups.com>
Message-ID: <CALwzidnwKpy-gN9LE3JkgwKOFD8M3hvySDL_x9ter6Hi2ptOQQ@mail.gmail.com>

On Fri, May 3, 2013 at 4:23 PM, Alex Gardner <agardner210 at gmail.com> wrote:
> When rect A collides with rect B they stick when I am wanting A to bounce off of B.  I have tried different methods, but none seem to work.  My source is here:  http://pastebin.com/CBYPcubL
>
> The collision code itself is below:
> ------
> # Bounce off of the paddle
> if paddle_rect.colliderect(ball_rect):
>     y_vel*=-1
>     x_vel*=-1

What may be happening is that even though you reversed the direction
of the ball's movement, in the next frame the paddle and ball are
still detected as colliding, so they get reversed again.  If that kept
happening over and over again, then the ball would appear to be
"sticking".  You should check the current direction of movement after
detecting the collision and only reverse it if it is not already going
the proper direction.

The other thing that is suspicious about the code you posted is that
it has two different notions of the ball's position that are not
necessarily in agreement.  There is the ball_rect, and there are also
the x and y variables.  You center the ball_rect from the x and y
variables (somewhat awkwardly; see below), so at that point they would
agree, but then you update the x and y variables without updating the
rect accordingly.  So before you get to the collision detection code,
the position of the ball on screen and the one that is used for the
collision detection may be somewhat different from the *actual*
position of the ball.  You should be careful to make sure these
variables agree at all times -- or better yet, get rid of x and y
entirely, so that you only have one notion of the ball's position to
worry about.

By the way, this code:

     boundsball_rect = pygame.Rect(x,y,0,0)
     ball_rect.clamp_ip(boundsball_rect)

could more simply be expressed as:

     ball_rect.center = (x, y)

Because that's all you're doing here: updating the position of the
rect.  If you take my advice and do away with the x and y variables,
then your position updating code:

     x += x_vel
     y += y_vel

could simply be:

     ball_rect.move_ip(x_vel, y_vel)


From joshua.landau.ws at gmail.com  Mon May  6 12:38:54 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Mon, 6 May 2013 17:38:54 +0100
Subject: Collision of Two Rect
In-Reply-To: <CALwzidnwKpy-gN9LE3JkgwKOFD8M3hvySDL_x9ter6Hi2ptOQQ@mail.gmail.com>
References: <9083ecbc-5666-41aa-aacb-3f08f062feed@googlegroups.com>
	<CALwzidnwKpy-gN9LE3JkgwKOFD8M3hvySDL_x9ter6Hi2ptOQQ@mail.gmail.com>
Message-ID: <CAN1F8qWTM=Oh9VqkApUFNZ5x9bwX149r_kPGhuoPY+Y21+z_+w@mail.gmail.com>

On 4 May 2013 00:42, Ian Kelly <ian.g.kelly at gmail.com> wrote:

> The other thing that is suspicious about the code you posted is that
> it has two different notions of the ball's position that are not
> necessarily in agreement.  There is the ball_rect, and there are also
> the x and y variables.

<snip>

> You should be careful to make sure these
> variables agree at all times -- or better yet, get rid of x and y
> entirely, so that you only have one notion of the ball's position to
> worry about.


Pygame uses integers for its Rects and thus I advise much the opposite:
*never* store position in Rects.

Sorry, but it's true. You'll need to keep x and y around and try to use
Rects only when representing pixels on the screen. Pygame has a lot of
deficiencies with its default set of objects and functions, so it's
something to get used to.
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From ian.g.kelly at gmail.com  Mon May  6 16:18:14 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 6 May 2013 14:18:14 -0600
Subject: Collision of Two Rect
In-Reply-To: <CAN1F8qWTM=Oh9VqkApUFNZ5x9bwX149r_kPGhuoPY+Y21+z_+w@mail.gmail.com>
References: <9083ecbc-5666-41aa-aacb-3f08f062feed@googlegroups.com>
	<CALwzidnwKpy-gN9LE3JkgwKOFD8M3hvySDL_x9ter6Hi2ptOQQ@mail.gmail.com>
	<CAN1F8qWTM=Oh9VqkApUFNZ5x9bwX149r_kPGhuoPY+Y21+z_+w@mail.gmail.com>
Message-ID: <CALwzidnm0geKvm=+A05TZB++FagSib6ZR8hA9siC5ZUwhwd_kw@mail.gmail.com>

On May 6, 2013 10:39 AM, "Joshua Landau" <joshua.landau.ws at gmail.com> wrote:
>
> On 4 May 2013 00:42, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>>
>> The other thing that is suspicious about the code you posted is that
>> it has two different notions of the ball's position that are not
>> necessarily in agreement.  There is the ball_rect, and there are also
>> the x and y variables.
>
> <snip>
>>
>> You should be careful to make sure these
>> variables agree at all times -- or better yet, get rid of x and y
>> entirely, so that you only have one notion of the ball's position to
>> worry about.
>
>
> Pygame uses integers for its Rects and thus I advise much the opposite:
*never* store position in Rects.
>
> Sorry, but it's true. You'll need to keep x and y around and try to use
Rects only when representing pixels on the screen. Pygame has a lot of
deficiencies with its default set of objects and functions, so it's
something to get used to.

You don't need subpixel positioning for many games -- arguably including
Pong, although I suppose the argument would be stronger if the OP were not
using a ludicrously high frame rate of 200 fps, which is going to limit the
number of reasonable integer velocities available.  For games where logical
coordinates and screen coordinates need to be separated though, I agree.
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From python at mrabarnett.plus.com  Fri May  3 20:51:01 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Sat, 04 May 2013 01:51:01 +0100
Subject: Collision of Two Rect
In-Reply-To: <9083ecbc-5666-41aa-aacb-3f08f062feed@googlegroups.com>
References: <9083ecbc-5666-41aa-aacb-3f08f062feed@googlegroups.com>
Message-ID: <51845B75.8030701@mrabarnett.plus.com>

On 03/05/2013 23:23, Alex Gardner wrote:
> When rect A collides with rect B they stick when I am wanting A to bounce off of B.  I have tried different methods, but none seem to work.  My source is here:  http://pastebin.com/CBYPcubL
>
> The collision code itself is below:
> ------
> # Bounce off of the paddle
> if paddle_rect.colliderect(ball_rect):
>      y_vel*=-1
>      x_vel*=-1
>
Apart from the other comments, I'm not sure about this line:

     y_vel = (math.fabs(2 - x_vel)**2) ** .5

Firstly, instead of math.fabs you could use abs:

     y_vel = (abs(2 - x_vel)**2) ** .5

Then again, you're squaring the result, and the square of (2 - x_vel)
will always be positive anyway:

     y_vel = ((2 - x_vel)**2) ** .5

You're also calculating getting the square root, for which math.sqrt 
would be simpler:

     y_vel = math.sqrt((2 - x_vel)**2)

Then again, you're calculating the square root of a squared number, so
you might as well just write:

     y_vel = abs(2 - x_vel)



From timr at probo.com  Sun May  5 01:28:28 2013
From: timr at probo.com (Tim Roberts)
Date: Sat, 04 May 2013 22:28:28 -0700
Subject: Collision of Two Rect
References: <9083ecbc-5666-41aa-aacb-3f08f062feed@googlegroups.com>
Message-ID: <v9rbo8l6apqd0itn1nbco2co884s16j9qu@4ax.com>

Alex Gardner <agardner210 at gmail.com> wrote:
>
>When rect A collides with rect B they stick when I am wanting A to bounce off of B.  I have tried different methods, but none seem to work.  My source is here:  http://pastebin.com/CBYPcubL
>
>The collision code itself is below:
>------
># Bounce off of the paddle
>if paddle_rect.colliderect(ball_rect):
>    y_vel*=-1
>    x_vel*=-1

I haven't looked at the rest of your code, but the lines you have here are
going to send the ball back in exactly the direction it came from -- a 180
degree reversal.  When a ball hits a paddle at an angle other than head on,
only ONE of the velocities is reversed.  When you hit a horizontal paddle,
only the Y velocity is negated.  The ball continues in the same X
direction:

    \    O
     \  /
      \/
   ========

See?  The X velocity continues unchanged until it hits a vertical wall.
-- 
Tim Roberts, timr at probo.com
Providenza & Boekelheide, Inc.


From pedro at ncf.ca  Fri May  3 22:13:16 2013
From: pedro at ncf.ca (Pedro)
Date: Fri, 3 May 2013 19:13:16 -0700 (PDT)
Subject: socket programming
Message-ID: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>

I'm writing a simple app that uses socket programming, I'm using the following from tutorialspoint as a framework but I'm having a couple of issues implementing it. 

First - this code constantly loops around an open socket. Is there a way to use something like an interrupt so I don't have to loop constantly to monitor the socket?

Second, if any part of the program fails execution (crashes) the port often remains open on my windows machine and the only way to close it that i know of is through task manager or by rebooting the machine. Is there an easy way around this problem ? If I don't close the port the program can't open it again and crashes.

Thanks for looking



SERVER:

import socket               # Import socket module

s = socket.socket()         # Create a socket object
host = socket.gethostname() # Get local machine name
port = 12345                # Reserve a port for your service.
s.bind((host, port))        # Bind to the port

s.listen(5)                 # Now wait for client connection.
while True:
   c, addr = s.accept()     # Establish connection with client.
   print 'Got connection from', addr
   c.send('Thank you for connecting')
   c.close()                # Close the connection

CLIENT:
import socket               # Import socket module

s = socket.socket()         # Create a socket object
host = socket.gethostname() # Get local machine name
port = 12345                # Reserve a port for your service.

s.connect((host, port))
print s.recv(1024)
s.close                     # Close the socket when done


From rosuav at gmail.com  Fri May  3 22:23:38 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 4 May 2013 12:23:38 +1000
Subject: socket programming
In-Reply-To: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
References: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
Message-ID: <CAPTjJmpedpot6b8e-jzCY92b9i6Z6nSeqYeWKaMfj--9jCouLg@mail.gmail.com>

On Sat, May 4, 2013 at 12:13 PM, Pedro <pedro at ncf.ca> wrote:
> First - this code constantly loops around an open socket. Is there a way to use something like an interrupt so I don't have to loop constantly to monitor the socket?

The accept() call should block. It's not going to spin or anything. If
you need to monitor multiple sockets, have a look at select().

> Second, if any part of the program fails execution (crashes) the port often remains open on my windows machine and the only way to close it that i know of is through task manager or by rebooting the machine. Is there an easy way around this problem ? If I don't close the port the program can't open it again and crashes.

It remains for a short time to ensure that there's no lurking
connections. You can bypass this check by setting the SO_REUSEADDR
option - lemme hunt that down in the Python docs, haven't done that in
Python for a while...

http://docs.python.org/3.3/library/socket.html#socket.socket.setsockopt

s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

That should do the job.

ChrisA


From pedro at ncf.ca  Fri May  3 23:37:35 2013
From: pedro at ncf.ca (Pedro)
Date: Fri, 3 May 2013 20:37:35 -0700 (PDT)
Subject: socket programming
In-Reply-To: <mailman.1282.1367634220.3114.python-list@python.org>
References: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
	<mailman.1282.1367634220.3114.python-list@python.org>
Message-ID: <c8534264-c126-4627-92b8-4aac056f81e3@googlegroups.com>

On Friday, May 3, 2013 10:23:38 PM UTC-4, Chris Angelico wrote:
> On Sat, May 4, 2013 at 12:13 PM, Pedro <pedro at ncf.ca> wrote:
> 
> > First - this code constantly loops around an open socket. Is there a way to use something like an interrupt so I don't have to loop constantly to monitor the socket?
> 
> 
> 
> The accept() call should block. It's not going to spin or anything. If
> 
> you need to monitor multiple sockets, have a look at select().
> 
> 
> 
> > Second, if any part of the program fails execution (crashes) the port often remains open on my windows machine and the only way to close it that i know of is through task manager or by rebooting the machine. Is there an easy way around this problem ? If I don't close the port the program can't open it again and crashes.
> 
> 
> 
> It remains for a short time to ensure that there's no lurking
> 
> connections. You can bypass this check by setting the SO_REUSEADDR
> 
> option - lemme hunt that down in the Python docs, haven't done that in
> 
> Python for a while...
> 
> 
> 
> http://docs.python.org/3.3/library/socket.html#socket.socket.setsockopt
> 
> 
> 
> s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
> 
> 
> 
> That should do the job.
> 
> 
> 
> ChrisA

Thanks Chris, can you elaborate on the accept() call should block?


From rosuav at gmail.com  Fri May  3 23:56:01 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 4 May 2013 13:56:01 +1000
Subject: socket programming
In-Reply-To: <c8534264-c126-4627-92b8-4aac056f81e3@googlegroups.com>
References: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
	<mailman.1282.1367634220.3114.python-list@python.org>
	<c8534264-c126-4627-92b8-4aac056f81e3@googlegroups.com>
Message-ID: <CAPTjJmqQJEb32QPwgXriH4FgpNYb5Fr7+mz9CPTpLVPAZ4FWXQ@mail.gmail.com>

On Sat, May 4, 2013 at 1:37 PM, Pedro <pedro at ncf.ca> wrote:
> On Friday, May 3, 2013 10:23:38 PM UTC-4, Chris Angelico wrote:
>> The accept() call should block. It's not going to spin or anything. If
>>
>> you need to monitor multiple sockets, have a look at select().
>
> Thanks Chris, can you elaborate on the accept() call should block?

When you call accept(), your program stops running until there's a
connection. It's like calling input() (or raw_input()) and your
program stopping until you type something. You can disable that by
setting the socket nonblocking, but I don't think you're doing that
here (and you probably don't want to).

Consider the accept() call to be, effectively, like reading from the
bound socket. In many ways it functions that way.

ChrisA


From pedro at ncf.ca  Sat May  4 00:03:25 2013
From: pedro at ncf.ca (Pedro)
Date: Fri, 3 May 2013 21:03:25 -0700 (PDT)
Subject: socket programming
In-Reply-To: <mailman.1283.1367639769.3114.python-list@python.org>
References: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
	<mailman.1282.1367634220.3114.python-list@python.org>
	<c8534264-c126-4627-92b8-4aac056f81e3@googlegroups.com>
	<mailman.1283.1367639769.3114.python-list@python.org>
Message-ID: <21c9450f-1da9-4acd-8f23-d90f71758bfb@googlegroups.com>

On Friday, May 3, 2013 11:56:01 PM UTC-4, Chris Angelico wrote:
> On Sat, May 4, 2013 at 1:37 PM, Pedro <pedro at ncf.ca> wrote:
> 
> > On Friday, May 3, 2013 10:23:38 PM UTC-4, Chris Angelico wrote:
> 
> >> The accept() call should block. It's not going to spin or anything. If
> 
> >>
> 
> >> you need to monitor multiple sockets, have a look at select().
> 
> >
> 
> > Thanks Chris, can you elaborate on the accept() call should block?
> 
> 
> 
> When you call accept(), your program stops running until there's a
> 
> connection. It's like calling input() (or raw_input()) and your
> 
> program stopping until you type something. You can disable that by
> 
> setting the socket nonblocking, but I don't think you're doing that
> 
> here (and you probably don't want to).
> 
> 
> 
> Consider the accept() call to be, effectively, like reading from the
> 
> bound socket. In many ways it functions that way.
> 
> 
> 
> ChrisA

Brilliant explanation Chris, I swear I read three different docs on that question and could not deduce what you just wrote. Thank you.


From irmen.NOSPAM at xs4all.nl  Sat May  4 05:37:42 2013
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Sat, 04 May 2013 11:37:42 +0200
Subject: socket programming
In-Reply-To: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
References: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
Message-ID: <5184d6e7$0$15976$e4fe514c@news.xs4all.nl>

On 4-5-2013 4:13, Pedro wrote:
> SERVER:
> 
> import socket               # Import socket module
> 
> s = socket.socket()         # Create a socket object
> host = socket.gethostname() # Get local machine name
> port = 12345                # Reserve a port for your service.
> s.bind((host, port))        # Bind to the port

This won't always work as expected, particularly on machines with multiple network
interfaces. Depending on what your situation requires, a simpler

s.bind(('', port))

can be more suitable. (empty string means INADDR_ANY)

> 
> s.listen(5)                 # Now wait for client connection.
> while True:
>    c, addr = s.accept()     # Establish connection with client.
>    print 'Got connection from', addr
>    c.send('Thank you for connecting')

The send() call returns the number of bytes actually sent. This number can be LESS than
the length of the buffer you wanted to send! So you will need a loop here to make sure
all data is actually transmitted.

The easiest way out is to use this instead:

c.sendall('Thank you for connecting')

However, this might fail due to some I/O error and then it leaves your socket in an
undetermined state because you can't tell how much of the data was actually transmitted.
(Recovering from errors is problematic if not impossible with sendall, as far as I know
the only thing you can do is just close the bad socket and create a new one)


>    c.close()                # Close the connection
> 
> CLIENT:
> import socket               # Import socket module
> 
> s = socket.socket()         # Create a socket object
> host = socket.gethostname() # Get local machine name
> port = 12345                # Reserve a port for your service.
> 
> s.connect((host, port))
> print s.recv(1024)

While this usually seems to work (especially with small buffer sizes) it has the same
problem as pointed out above with send(): recv() might not retrieve all data at once. It
returns the amount of data actually received in that call.

[warning, hairy details below]

You HAVE to make a loop here to get all chunks of data until they add up to the total
data size that you expected. (There's a flag MSG_WAITALL you can pass to recv to get
around this. But it is not available on all systems, and on some systems where it is
provided, it doesn't work correctly.) Also you need to be careful with the buffer size
passed to recv, too large and it causes problems on some systems. Around 60kb seems a
good upper bound here.

This usually also means you need to somehow tell the receiving end of the socket how
much data is to be expected, and only then send that actual data. One way to do this is
to send the length first as a struct-packed integer (4 bytes), and the data after that.
Note that even reading the 4 bytes on the receiving side to determine the expected
length might be broken up in multiple chunks: you can't even expect recv(4) to always
return those 4 bytes. So even that needs to be in a loop...

Other ways to know on the receiving end when to stop reading from the socket is to
standardize on some sort of termination character (such as '\0' or perhaps '\n'), fixed
length buffers, or to always close the socket after every single message (but that is
hugely inefficient if you need to send multiple messages).


> s.close                     # Close the socket when done
> 

Oh, you forgot the parentheses here:

s.close()


Bottom line:
Socket programming on this level is hugely complicated. It doesn't seem too bad if you
start of with these simple example programs, but that's false hope. If at all possible,
avoid direct socket programming, and use a high-level protocol or library instead
(ftp/http/some IPC library/Twisted). Let them deal with the complexity of the socket layer.


Regards

Irmen de Jong



From rosuav at gmail.com  Sat May  4 06:00:39 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 4 May 2013 20:00:39 +1000
Subject: socket programming
In-Reply-To: <5184d6e7$0$15976$e4fe514c@news.xs4all.nl>
References: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
	<5184d6e7$0$15976$e4fe514c@news.xs4all.nl>
Message-ID: <CAPTjJmo3YHw5MUbFyeUqvBrXjkQ2-8VVWY6xQQkR4xVUJ5YcBQ@mail.gmail.com>

On Sat, May 4, 2013 at 7:37 PM, Irmen de Jong <irmen.NOSPAM at xs4all.nl> wrote:
> Bottom line:
> Socket programming on this level is hugely complicated. It doesn't seem too bad if you
> start of with these simple example programs, but that's false hope. If at all possible,
> avoid direct socket programming, and use a high-level protocol or library instead
> (ftp/http/some IPC library/Twisted). Let them deal with the complexity of the socket layer.
>

It's not quite as bad as this paragraph seems to imply. Sure, there
are a million things that can go wrong, but once you master that, it's
the very easiest way to do cross-language, cross-platform,
cross-computer communication. Practically EVERY language can do basic
TCP sockets, but not every language has higher level bindings.

ChrisA


From pedro at ncf.ca  Mon May  6 11:54:57 2013
From: pedro at ncf.ca (Pedro)
Date: Mon, 6 May 2013 08:54:57 -0700 (PDT)
Subject: socket programming
In-Reply-To: <5184d6e7$0$15976$e4fe514c@news.xs4all.nl>
References: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
	<5184d6e7$0$15976$e4fe514c@news.xs4all.nl>
Message-ID: <5456a5e5-17f6-4e9a-a29c-490a17c1de44@googlegroups.com>

On Saturday, May 4, 2013 5:37:42 AM UTC-4, Irmen de Jong wrote:
> On 4-5-2013 4:13, Pedro wrote: > SERVER: > > import socket # Import socket module > > s = socket.socket() # Create a socket object > host = socket.gethostname() # Get local machine name > port = 12345 # Reserve a port for your service. > s.bind((host, port)) # Bind to the port This won't always work as expected, particularly on machines with multiple network interfaces. Depending on what your situation requires, a simpler s.bind(('', port)) can be more suitable. (empty string means INADDR_ANY) > > s.listen(5) # Now wait for client connection. > while True: > c, addr = s.accept() # Establish connection with client. > print 'Got connection from', addr > c.send('Thank you for connecting') The send() call returns the number of bytes actually sent. This number can be LESS than the length of the buffer you wanted to send! So you will need a loop here to make sure all data is actually transmitted. The easiest way out is to use this instead: c.sendall('Thank you for connecting') However, this might fail due to some I/O error and then it leaves your socket in an undetermined state because you can't tell how much of the data was actually transmitted. (Recovering from errors is problematic if not impossible with sendall, as far as I know the only thing you can do is just close the bad socket and create a new one) > c.close() # Close the connection > > CLIENT: > import socket # Import socket module > > s = socket.socket() # Create a socket object > host = socket.gethostname() # Get local machine name > port = 12345 # Reserve a port for your service. > > s.connect((host, port)) > print s.recv(1024) While this usually seems to work (especially with small buffer sizes) it has the same problem as pointed out above with send(): recv() might not retrieve all data at once. It returns the amount of data actually received in that call. [warning, hairy details below] You HAVE to make a loop here to get all chunks of data until they add up to the total data size that you expected. (There's a flag MSG_WAITALL you can pass to recv to get around this. But it is not available on all systems, and on some systems where it is provided, it doesn't work correctly.) Also you need to be careful with the buffer size passed to recv, too large and it causes problems on some systems. Around 60kb seems a good upper bound here. This usually also means you need to somehow tell the receiving end of the socket how much data is to be expected, and only then send that actual data. One way to do this is to send the length first as a struct-packed integer (4 bytes), and the data after that. Note that even reading the 4 bytes on the receiving side to determine the expected length might be broken up in multiple chunks: you can't even expect recv(4) to always return those 4 bytes. So even that needs to be in a loop... Other ways to know on the receiving end when to stop reading from the socket is to standardize on some sort of termination character (such as '\0' or perhaps '\n'), fixed length buffers, or to always close the socket after every single message (but that is hugely inefficient if you need to send multiple messages). > s.close # Close the socket when done > Oh, you forgot the parentheses here: s.close() Bottom line: Socket programming on this level is hugely complicated. It doesn't seem too bad if you start of with these simple example programs, but that's false hope. If at all possible, avoid direct socket programming, and use a high-level protocol or library instead (ftp/http/some IPC library/Twisted). Let them deal with the complexity of the socket layer. Regards Irmen de Jong

Thanks for the reply. I'm sending short strings as commands to my server machine so the socket module seems to be doing the trick reliably. I'll try to add Twisted to my arsenal though. 
Cheers


From rosuav at gmail.com  Mon May  6 12:05:43 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 7 May 2013 02:05:43 +1000
Subject: socket programming
In-Reply-To: <5456a5e5-17f6-4e9a-a29c-490a17c1de44@googlegroups.com>
References: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
	<5184d6e7$0$15976$e4fe514c@news.xs4all.nl>
	<5456a5e5-17f6-4e9a-a29c-490a17c1de44@googlegroups.com>
Message-ID: <CAPTjJmpfbPbwp==11P=09FXpbS77c8bfgSYJ9jcmL7RQJ0ytmQ@mail.gmail.com>

On Tue, May 7, 2013 at 1:54 AM, Pedro <pedro at ncf.ca> wrote:
> Thanks for the reply. I'm sending short strings as commands to my server machine so the socket module seems to be doing the trick reliably. I'll try to add Twisted to my arsenal though.
> Cheers

I've never used Twisted, so I can't say how good it is. All I know is
that what I learned about socket programming in C on OS/2 is still
valid on Windows and on Linux, and in every language I've ever used
(bar JavaScript and ActionScript, which are deliberately sandboxed and
thus don't have direct socket calls available). So take your pick: Go
with Twisted, and bind yourself to a particular library, or go with
BSD sockets, and do the work yourself. Like everything else in
programming, it's a tradeoff.

ChrisA


From arnodel at gmail.com  Mon May  6 14:54:17 2013
From: arnodel at gmail.com (Arnaud Delobelle)
Date: Mon, 6 May 2013 19:54:17 +0100
Subject: socket programming
In-Reply-To: <CAPTjJmpfbPbwp==11P=09FXpbS77c8bfgSYJ9jcmL7RQJ0ytmQ@mail.gmail.com>
References: <4aef55bd-f550-4a3d-b11a-285b6fa9892b@googlegroups.com>
	<5184d6e7$0$15976$e4fe514c@news.xs4all.nl>
	<5456a5e5-17f6-4e9a-a29c-490a17c1de44@googlegroups.com>
	<CAPTjJmpfbPbwp==11P=09FXpbS77c8bfgSYJ9jcmL7RQJ0ytmQ@mail.gmail.com>
Message-ID: <CAJ6cK1YGSpsAQ6ECK5mR=P=osJHSJ6QZNT8W2JGNoD-PnYZkWw@mail.gmail.com>

On 6 May 2013 17:05, Chris Angelico <rosuav at gmail.com> wrote:

> I've never used Twisted, so I can't say how good it is. All I know is
> that what I learned about socket programming in C on OS/2 is still
> valid on Windows and on Linux, and in every language I've ever used
> (bar JavaScript and ActionScript, which are deliberately sandboxed and
> thus don't have direct socket calls available). So take your pick: Go
> with Twisted, and bind yourself to a particular library, or go with
> BSD sockets, and do the work yourself. Like everything else in
> programming, it's a tradeoff.

OTOH Twisted can handle much more than socket programming. On the
third hand Twisted has its own learning curve as well...

-- 
Arnaud


From jimmie.he at gmail.com  Sat May  4 06:37:54 2013
From: jimmie.he at gmail.com (Jimmie He)
Date: Sat, 4 May 2013 03:37:54 -0700 (PDT)
Subject: About py2exe "bundle_files" setting?
Message-ID: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>

Hi Guys,
   Now I met an issue to use py2exe when I use bundle_files = 1.As the statement by py2exe,it means it will generate standalone EXE in stead of lots of ".dll & .pyc".But it crash when I use bundle_files = 1 or bundle_files = 2,if I use =3 it is okey.I 've search this issue by google, it is not the Individual case only by me!!! Any guru have the advice for this?I use python 2.7.4 and the py2exe version is 0.6.9(latest).If anyone have the direction I'll share my full package.

Attach my setup.py as below->

from distutils.core import setup
import py2exe


includes = ["encodings", "encodings.*"]   

options = {"py2exe":
    {"compressed": 1,
     "optimize": 2,
     "ascii": 1,
     "includes":includes,
     "bundle_files": 3}
    }

setup (options = options, zipfile=None, windows=["./Gui.py"])


From steve+comp.lang.python at pearwood.info  Sat May  4 07:31:04 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 04 May 2013 11:31:04 GMT
Subject: About py2exe "bundle_files" setting?
References: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>
Message-ID: <5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sat, 04 May 2013 03:37:54 -0700, Jimmie He wrote:

> Hi Guys,
>    Now I met an issue to use py2exe when I use bundle_files = 1.As the
>    statement by py2exe,it means it will generate standalone EXE in stead
>    of lots of ".dll & .pyc".But it crash when I use bundle_files = 1 or
>    bundle_files = 2,if I use =3 it is okey.

It crashes? Do you mean a Blue Screen of Death?

Can you copy and paste the error message that you get please.


-- 
Steven


From jimmie.he at gmail.com  Sat May  4 07:59:02 2013
From: jimmie.he at gmail.com (Jimmie He)
Date: Sat, 4 May 2013 04:59:02 -0700 (PDT)
Subject: About py2exe "bundle_files" setting?
In-Reply-To: <5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>
	<5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <60ef30af-bc46-433a-9f1e-c31879352fa3@googlegroups.com>

? 2013?5?4????UTC+8??7?31?04??Steven D'Aprano???
> On Sat, 04 May 2013 03:37:54 -0700, Jimmie He wrote:
> 
> 
> 
> > Hi Guys,
> 
> >    Now I met an issue to use py2exe when I use bundle_files = 1.As the
> 
> >    statement by py2exe,it means it will generate standalone EXE in stead
> 
> >    of lots of ".dll & .pyc".But it crash when I use bundle_files = 1 or
> 
> >    bundle_files = 2,if I use =3 it is okey.
> 
> 
> 
> It crashes? Do you mean a Blue Screen of Death?
> 
> 
> 
> Can you copy and paste the error message that you get please.
> 
> 
> 
> 
> 
> -- 
> 
> Steven

Hi Steven,
   I 've already put my project into GitHub,find the link below,in the folder "Bug",I capture the expection pops up,it is not fatal blue screen.Sorry for my non-english windows:-)
https://github.com/jimmiehe/BMPtool/tree/master/Bug


From jimmie.he at gmail.com  Sat May  4 07:59:13 2013
From: jimmie.he at gmail.com (Jimmie He)
Date: Sat, 4 May 2013 04:59:13 -0700 (PDT)
Subject: About py2exe "bundle_files" setting?
In-Reply-To: <5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>
	<5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <75fbdb5d-e7c1-49e8-bd5b-ebf6fe78e970@googlegroups.com>

? 2013?5?4????UTC+8??7?31?04??Steven D'Aprano???
> On Sat, 04 May 2013 03:37:54 -0700, Jimmie He wrote:
> 
> 
> 
> > Hi Guys,
> 
> >    Now I met an issue to use py2exe when I use bundle_files = 1.As the
> 
> >    statement by py2exe,it means it will generate standalone EXE in stead
> 
> >    of lots of ".dll & .pyc".But it crash when I use bundle_files = 1 or
> 
> >    bundle_files = 2,if I use =3 it is okey.
> 
> 
> 
> It crashes? Do you mean a Blue Screen of Death?
> 
> 
> 
> Can you copy and paste the error message that you get please.
> 
> 
> 
> 
> 
> -- 
> 
> Steven

Hi Steven,
   I 've already put my project into GitHub,find the link below,in the folder "Bug",I capture the expection pops up,it is not fatal blue screen.Sorry for my non-english windows:-)
https://github.com/jimmiehe/BMPtool/tree/master/Bug


From steve+comp.lang.python at pearwood.info  Sat May  4 09:42:07 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 04 May 2013 13:42:07 GMT
Subject: About py2exe "bundle_files" setting?
References: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>
	<5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<75fbdb5d-e7c1-49e8-bd5b-ebf6fe78e970@googlegroups.com>
Message-ID: <5185102f$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sat, 04 May 2013 04:59:13 -0700, Jimmie He wrote:

>    I 've already put my project into GitHub,find the link below,in the
>    folder "Bug",I capture the expection pops up,it is not fatal blue
>    screen.Sorry for my non-english windows:-)
> https://github.com/jimmiehe/BMPtool/tree/master/Bug


I cannot access that page, it just loads as a blank page, then locks up 
my browser. (This is what happens when stupid websites use too much buggy 
javascript for simple things which are best handled by ordinary html.)

Please copy and paste the exception *as text* here, if you can.


-- 
Steven


From rosuav at gmail.com  Sat May  4 10:50:14 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 5 May 2013 00:50:14 +1000
Subject: About py2exe "bundle_files" setting?
In-Reply-To: <5185102f$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>
	<5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<75fbdb5d-e7c1-49e8-bd5b-ebf6fe78e970@googlegroups.com>
	<5185102f$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmp_069mCdf++eWnYmJq6P4RnVYjysGXNc7pu5Z9xjWOew@mail.gmail.com>

On Sat, May 4, 2013 at 11:42 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Sat, 04 May 2013 04:59:13 -0700, Jimmie He wrote:
>
>>    I 've already put my project into GitHub,find the link below,in the
>>    folder "Bug",I capture the expection pops up,it is not fatal blue
>>    screen.Sorry for my non-english windows:-)
>> https://github.com/jimmiehe/BMPtool/tree/master/Bug
>
>
> I cannot access that page, it just loads as a blank page, then locks up
> my browser. (This is what happens when stupid websites use too much buggy
> javascript for simple things which are best handled by ordinary html.)
>
> Please copy and paste the exception *as text* here, if you can.

It's not a Python exception. The message has just a few words of
English, interspersed with a lot of Chinese, which I am in no way
skilled enough to transcribe, much less translate; the title says
"Gui.exe - [#######]" and the body says:

"0x00fb1cb" [#######] "0x00000000" [########] "written",,
and then two lines of all Chinese.

Hope that's of at least some help! Sorry I can't be more accurate in
the translation.

ChrisA


From jimmie.he at gmail.com  Sat May  4 11:42:53 2013
From: jimmie.he at gmail.com (Jimmie He)
Date: Sat, 4 May 2013 08:42:53 -0700 (PDT)
Subject: About py2exe "bundle_files" setting?
In-Reply-To: <mailman.1287.1367679023.3114.python-list@python.org>
References: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>
	<5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<75fbdb5d-e7c1-49e8-bd5b-ebf6fe78e970@googlegroups.com>
	<5185102f$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1287.1367679023.3114.python-list@python.org>
Message-ID: <3fb60011-b8db-4af1-929d-0c5bd7cd5db7@googlegroups.com>

? 2013?5?4????UTC+8??10?50?14??Chris Angelico???
> On Sat, May 4, 2013 at 11:42 PM, Steven D'Aprano
> 
> <steve+comp.lang.python at pearwood.info> wrote:
> 
> > On Sat, 04 May 2013 04:59:13 -0700, Jimmie He wrote:
> 
> >
> 
> >>    I 've already put my project into GitHub,find the link below,in the
> 
> >>    folder "Bug",I capture the expection pops up,it is not fatal blue
> 
> >>    screen.Sorry for my non-english windows:-)
> 
> >> https://github.com/jimmiehe/BMPtool/tree/master/Bug
> 
> >
> 
> >
> 
> > I cannot access that page, it just loads as a blank page, then locks up
> 
> > my browser. (This is what happens when stupid websites use too much buggy
> 
> > javascript for simple things which are best handled by ordinary html.)
> 
> >
> 
> > Please copy and paste the exception *as text* here, if you can.
> 
> 
> 
> It's not a Python exception. The message has just a few words of
> 
> English, interspersed with a lot of Chinese, which I am in no way
> 
> skilled enough to transcribe, much less translate; the title says
> 
> "Gui.exe - [#######]" and the body says:
> 
> 
> 
> "0x00fb1cb" [#######] "0x00000000" [########] "written",,
> 
> and then two lines of all Chinese.
> 
> 
> 
> Hope that's of at least some help! Sorry I can't be more accurate in
> 
> the translation.
> 
> 
> 
> ChrisA

ChrisA & Steven,
   Let me translet it:-)
 "Application error. The instruction at "0x00fb1cb" referenced memory at "0x00000000 can not be written" It seems miss some lib after package by py2exe.

It is not an python error,which I mean is that after I package my application by py2exe(without any error),then I run the target .exe which packaged by py2exe, it crashed.



From rosuav at gmail.com  Sat May  4 11:49:33 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 5 May 2013 01:49:33 +1000
Subject: About py2exe "bundle_files" setting?
In-Reply-To: <3fb60011-b8db-4af1-929d-0c5bd7cd5db7@googlegroups.com>
References: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>
	<5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<75fbdb5d-e7c1-49e8-bd5b-ebf6fe78e970@googlegroups.com>
	<5185102f$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1287.1367679023.3114.python-list@python.org>
	<3fb60011-b8db-4af1-929d-0c5bd7cd5db7@googlegroups.com>
Message-ID: <CAPTjJmrOg8enSEqQDwJ3c0jbTCVFMq4iCesc4X0x88-h1Xopdg@mail.gmail.com>

On Sun, May 5, 2013 at 1:42 AM, Jimmie He <jimmie.he at gmail.com> wrote:
> ? 2013?5?4????UTC+8??10?50?14??Chris Angelico???
>> On Sat, May 4, 2013 at 11:42 PM, Steven D'Aprano
>>
>> <steve+comp.lang.python at pearwood.info> wrote:
>>
>> > On Sat, 04 May 2013 04:59:13 -0700, Jimmie He wrote:
>>
>> >
>>
>> >>    I 've already put my project into GitHub,find the link below,in the
>>
>> >>    folder "Bug",I capture the expection pops up,it is not fatal blue
>>
>> >>    screen.Sorry for my non-english windows:-)
>>
>> >> https://github.com/jimmiehe/BMPtool/tree/master/Bug
>>
>> >
>>
>> >
>>
>> > I cannot access that page, it just loads as a blank page, then locks up
>>
>> > my browser. (This is what happens when stupid websites use too much buggy
>>
>> > javascript for simple things which are best handled by ordinary html.)
>>
>> >
>>
>> > Please copy and paste the exception *as text* here, if you can.
>>
>>
>>
>> It's not a Python exception. The message has just a few words of
>>
>> English, interspersed with a lot of Chinese, which I am in no way
>>
>> skilled enough to transcribe, much less translate; the title says
>>
>> "Gui.exe - [#######]" and the body says:
>>
>>
>>
>> "0x00fb1cb" [#######] "0x00000000" [########] "written",,
>>
>> and then two lines of all Chinese.
>>
>>
>>
>> Hope that's of at least some help! Sorry I can't be more accurate in
>>
>> the translation.
>>
>>
>>
>> ChrisA
>
> ChrisA & Steven,
>    Let me translet it:-)
>  "Application error. The instruction at "0x00fb1cb" referenced memory at "0x00000000 can not be written" It seems miss some lib after package by py2exe.
>
> It is not an python error,which I mean is that after I package my application by py2exe(without any error),then I run the target .exe which packaged by py2exe, it crashed.

Thanks for the translation, Jimmie! I figured it was some sort of C-level crash.

Unfortunately it's fairly non-specific. Are you able to make _any_
program work with py2exe using bundle_files = 1? If you can make a
simple "Hello, world" work but your current program isn't working, I'd
start looking through the dependencies; if not, I'd check py2exe
itself. But I can't help much there, as I've never used py2exe.

ChrisA


From jimmie.he at gmail.com  Sat May  4 12:27:20 2013
From: jimmie.he at gmail.com (Jimmie He)
Date: Sat, 4 May 2013 09:27:20 -0700 (PDT)
Subject: About py2exe "bundle_files" setting?
In-Reply-To: <mailman.1288.1367682581.3114.python-list@python.org>
References: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>
	<5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<75fbdb5d-e7c1-49e8-bd5b-ebf6fe78e970@googlegroups.com>
	<5185102f$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1287.1367679023.3114.python-list@python.org>
	<3fb60011-b8db-4af1-929d-0c5bd7cd5db7@googlegroups.com>
	<mailman.1288.1367682581.3114.python-list@python.org>
Message-ID: <6d24ba51-db8a-4e3a-86ce-8704e90f4374@googlegroups.com>

? 2013?5?4????UTC+8??11?49?33??Chris Angelico???
> On Sun, May 5, 2013 at 1:42 AM, Jimmie He <jimmie.he at gmail.com> wrote:
> 
> > ? 2013?5?4????UTC+8??10?50?14??Chris Angelico???
> 
> >> On Sat, May 4, 2013 at 11:42 PM, Steven D'Aprano
> 
> >>
> 
> >> <steve+comp.lang.python at pearwood.info> wrote:
> 
> >>
> 
> >> > On Sat, 04 May 2013 04:59:13 -0700, Jimmie He wrote:
> 
> >>
> 
> >> >
> 
> >>
> 
> >> >>    I 've already put my project into GitHub,find the link below,in the
> 
> >>
> 
> >> >>    folder "Bug",I capture the expection pops up,it is not fatal blue
> 
> >>
> 
> >> >>    screen.Sorry for my non-english windows:-)
> 
> >>
> 
> >> >> https://github.com/jimmiehe/BMPtool/tree/master/Bug
> 
> >>
> 
> >> >
> 
> >>
> 
> >> >
> 
> >>
> 
> >> > I cannot access that page, it just loads as a blank page, then locks up
> 
> >>
> 
> >> > my browser. (This is what happens when stupid websites use too much buggy
> 
> >>
> 
> >> > javascript for simple things which are best handled by ordinary html.)
> 
> >>
> 
> >> >
> 
> >>
> 
> >> > Please copy and paste the exception *as text* here, if you can.
> 
> >>
> 
> >>
> 
> >>
> 
> >> It's not a Python exception. The message has just a few words of
> 
> >>
> 
> >> English, interspersed with a lot of Chinese, which I am in no way
> 
> >>
> 
> >> skilled enough to transcribe, much less translate; the title says
> 
> >>
> 
> >> "Gui.exe - [#######]" and the body says:
> 
> >>
> 
> >>
> 
> >>
> 
> >> "0x00fb1cb" [#######] "0x00000000" [########] "written",,
> 
> >>
> 
> >> and then two lines of all Chinese.
> 
> >>
> 
> >>
> 
> >>
> 
> >> Hope that's of at least some help! Sorry I can't be more accurate in
> 
> >>
> 
> >> the translation.
> 
> >>
> 
> >>
> 
> >>
> 
> >> ChrisA
> 
> >
> 
> > ChrisA & Steven,
> 
> >    Let me translet it:-)
> 
> >  "Application error. The instruction at "0x00fb1cb" referenced memory at "0x00000000 can not be written" It seems miss some lib after package by py2exe.
> 
> >
> 
> > It is not an python error,which I mean is that after I package my application by py2exe(without any error),then I run the target .exe which packaged by py2exe, it crashed.
> 
> 
> 
> Thanks for the translation, Jimmie! I figured it was some sort of C-level crash.
> 
> 
> 
> Unfortunately it's fairly non-specific. Are you able to make _any_
> 
> program work with py2exe using bundle_files = 1? If you can make a
> 
> simple "Hello, world" work but your current program isn't working, I'd
> 
> start looking through the dependencies; if not, I'd check py2exe
> 
> itself. But I can't help much there, as I've never used py2exe.
> 
> 
> 
> ChrisA

Hi ChrisA,
   I tested an 'hello world' by the set (bundle_files = 1),it is well worked! Yes,maybe due to the dependencies.


From rosuav at gmail.com  Sat May  4 12:36:45 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 5 May 2013 02:36:45 +1000
Subject: About py2exe "bundle_files" setting?
In-Reply-To: <6d24ba51-db8a-4e3a-86ce-8704e90f4374@googlegroups.com>
References: <219a9209-5c6a-4380-bd11-3db00584737d@googlegroups.com>
	<5184f178$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<75fbdb5d-e7c1-49e8-bd5b-ebf6fe78e970@googlegroups.com>
	<5185102f$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1287.1367679023.3114.python-list@python.org>
	<3fb60011-b8db-4af1-929d-0c5bd7cd5db7@googlegroups.com>
	<mailman.1288.1367682581.3114.python-list@python.org>
	<6d24ba51-db8a-4e3a-86ce-8704e90f4374@googlegroups.com>
Message-ID: <CAPTjJmpyvmpU7=tacKzYVWAn3is6=u84tLDMFrXXr1j4pkR3Cg@mail.gmail.com>

On Sun, May 5, 2013 at 2:27 AM, Jimmie He <jimmie.he at gmail.com> wrote:
> ? 2013?5?4????UTC+8??11?49?33??Chris Angelico???
>> Unfortunately it's fairly non-specific. Are you able to make _any_
>>
>> program work with py2exe using bundle_files = 1? If you can make a
>>
>> simple "Hello, world" work but your current program isn't working, I'd
>>
>> start looking through the dependencies; if not, I'd check py2exe
>>
>> itself. But I can't help much there, as I've never used py2exe.
>>
>
> Hi ChrisA,
>    I tested an 'hello world' by the set (bundle_files = 1),it is well worked! Yes,maybe due to the dependencies.

Alright! Now starts the progressive search to find out _which_
dependency it is :)

By the way, can you please trim your quoted text? Also, you're
double-spacing it all. This suggests to my mind that you're most
likely using Google Groups, which is hated by quite a few on this list
and defended by a handful; if you can get yourself off it, you'll
likely find a better audience to your posts - as there are some who
hate it enough to filter out everything that comes from there.

If you _must_ use GG, please have a read of this page:

http://wiki.python.org/moin/GoogleGroupsPython

That'll help you avoid some of the problems. If it feels very manual,
that's because it is; I strongly recommend finding a different way to
post.

Chris Angelico


From techgeek201 at gmail.com  Sat May  4 14:57:48 2013
From: techgeek201 at gmail.com (eli m)
Date: Sat, 4 May 2013 11:57:48 -0700 (PDT)
Subject: Video tutorial for making a guess the number game in python
Message-ID: <75cf0c56-2352-4f52-a731-5da9c773bd6c@googlegroups.com>

I made a video tutorial for making a guess the number game in python. You can check it out here: http://www.youtube.com/watch?v=0WSQb-7wMJQ


From pwberrett at gmail.com  Sun May  5 02:06:59 2013
From: pwberrett at gmail.com (peter berrett)
Date: Sat, 4 May 2013 23:06:59 -0700 (PDT)
Subject: Help with loading file into an array
Message-ID: <c4a4e4ee-11c9-4b5e-a24a-10be49a4ce5d@googlegroups.com>

Hi all

I am trying to build a program that can find comets in a series of astronomical images. I have already written functions to find the comet in a series of images, the data of which is stored in embedded lists.

The area I am having difficulty with is take a standard gif file (1024 x 1024) and reading it into an array or embedded lists.

In a nutshell here is an example of what I want to do

Let's say I have a gif file called 20130428_0000_c2_1024.gif in a folder called c:\comets

I want to read the data from that gif file taking the red data (excluding the green and blue data) and store that in an array called Image[][] which is a nested array length 1024 with a list in each item of 1024 length (ie 1024 x 1024)

Could someone please provide a piece of code to do the above so I can then go on to modify it to pick up different files from different folders? In particular I am keen to seen how you read in the data and also how you change the directory from which you are reading the image.

For the record this is not for homework but is a pet project of mine. I have already written a version of the program in Justbasic but python is faster. I am also interested in readers views as to which is the simplest and best way to achieve what I am trying to do.


Thanks Peter


From fabiosantosart at gmail.com  Sun May  5 03:43:21 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sun, 5 May 2013 08:43:21 +0100
Subject: Help with loading file into an array
In-Reply-To: <c4a4e4ee-11c9-4b5e-a24a-10be49a4ce5d@googlegroups.com>
References: <c4a4e4ee-11c9-4b5e-a24a-10be49a4ce5d@googlegroups.com>
Message-ID: <CAA=1kxRDPfXV11cS3S+6DEohzLfVvoQnSXCtf7TYxwi=ofoA1w@mail.gmail.com>

Using a nested array should waste a lot of memory. I think you should use
PIL to load and read the image.

>
> I want to read the data from that gif file taking the red data (excluding
the green and blue data) and store that in an array called Image[][] which
is a nested array length 1024 with a list in each item of 1024 length (ie
1024 x 1024)
>
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From cjw at ncf.ca  Sun May  5 07:42:22 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Sun, 05 May 2013 07:42:22 -0400
Subject: Help with loading file into an array
In-Reply-To: <mailman.1290.1367740305.3114.python-list@python.org>
References: <c4a4e4ee-11c9-4b5e-a24a-10be49a4ce5d@googlegroups.com>
	<mailman.1290.1367740305.3114.python-list@python.org>
Message-ID: <km5gj7$mk2$1@theodyn.ncf.ca>

On 05/05/2013 3:43 AM, F?bio Santos wrote:
> Using a nested array should waste a lot of memory. I think you should
> use PIL to load and read the image.
>
>  >
>  > I want to read the data from that gif file taking the red data
> (excluding the green and blue data) and store that in an array called
> Image[][] which is a nested array length 1024 with a list in each item
> of 1024 length (ie 1024 x 1024)
>  >
>
Fabio,

Have you considered numpy?

Colin W.


From jt at toerring.de  Sun May  5 07:44:19 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 5 May 2013 11:44:19 GMT
Subject: Help with loading file into an array
References: <c4a4e4ee-11c9-4b5e-a24a-10be49a4ce5d@googlegroups.com>
Message-ID: <aumv0jFfjh5U1@mid.uni-berlin.de>

peter berrett <pwberrett at gmail.com> wrote:
> I am trying to build a program that can find comets in a series of
> astronomical images. I have already written functions to find the comet in a
> series of images, the data of which is stored in embedded lists.

> The area I am having difficulty with is take a standard gif file (1024 x
> 1024) and reading it into an array or embedded lists.

> In a nutshell here is an example of what I want to do

> Let's say I have a gif file called 20130428_0000_c2_1024.gif in a folder
> called c:\comets

> I want to read the data from that gif file taking the red data (excluding
> the green and blue data) and store that in an array called Image[][] which
> is a nested array length 1024 with a list in each item of 1024 length (ie
> 1024 x 1024)

> Could someone please provide a piece of code to do the above so I can then
> go on to modify it to pick up different files from different folders? In
> particular I am keen to seen how you read in the data and also how you
> change the directory from which you are reading the image. >

the following should do the trick using, as F?bio already
suggested, the Python Image Library (PIL):

----------------8<-------------------------
#!/ur/bin/env python

import Image

im = Image.open( 'c:/comets/20130428_0000_c2_1024.gif' )
w, h = im.size
red_arr = [ ]
for y in range( h ) :
    red_line = [ ]
    for x in range( w ) :
        red_line.append( im.getpixel( ( x, y ) )[ 0 ] )
    red_arr.append( red_line )
----------------8<-------------------------

For obvious reasons I couldn't use 'Image' as the name of the list
of lists, so it's 'red_arr' instead. This is probably not the fas-
test solution, but it's simple and hopefully will get you started.

Concerning reading other files: here I may not understand your
problem since it looks rather trivial to me by simply passing
the open() method of 'Image' the name of a file in a different
directory.
                             Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From joshua.landau.ws at gmail.com  Mon May  6 12:28:34 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Mon, 6 May 2013 17:28:34 +0100
Subject: Help with loading file into an array
In-Reply-To: <c4a4e4ee-11c9-4b5e-a24a-10be49a4ce5d@googlegroups.com>
References: <c4a4e4ee-11c9-4b5e-a24a-10be49a4ce5d@googlegroups.com>
Message-ID: <CAN1F8qUPY1wuJzWmenBi25MdUvE1n3ABTDPaLXXD9ojVC6Cipw@mail.gmail.com>

On 5 May 2013 07:06, peter berrett <pwberrett at gmail.com> wrote:

> I am trying to build a program that can find comets in a series of
> astronomical images. I have already written functions to find the comet in
> a series of images, the data of which is stored in embedded lists.
>
> The area I am having difficulty with is take a standard gif file (1024 x
> 1024) and reading it into an array or embedded lists.
>

This is not what you should really be doing. There are specialised things
for this.

Take a look at PIL (http://www.pythonware.com/products/pil/).
It will install as "Image" and from there you can do:

import Image
image = Image.open("FILE")
pixels = image.load()

and access the pixels like:

pixels[x, y] # You get (r, g, b) tuple of integers from 0 to 255


> In a nutshell here is an example of what I want to do
>
> Let's say I have a gif file called 20130428_0000_c2_1024.gif in a folder
> called c:\comets
>
> I want to read the data from that gif file taking the red data (excluding
> the green and blue data) and store that in an array called Image[][] which
> is a nested array length 1024 with a list in each item of 1024 length (ie
> 1024 x 1024)
>

*Ahem*:
1) Python standard is to only uppercase class (and sometimes module) names,
so it should just be "image".
2) Technically, you mean list.
3) Chose the above method instead, so instead of indexing it with
"image[x][y]" you use "image[x, y]".

Now, you only want the red channel. What this means is that you want to
"split" the image into channels before using image.load():

import Image

image = Image.open("FILE")
image.load() # .open is lazy, so you have to load now

red, green, blue = image.split()
red_pixels = red.load()

And you access as before:

red_pixels[x, y] # You get integer from 0 to 255

Could someone please provide a piece of code to do the above so I can then
> go on to modify it to pick up different files from different folders? In
> particular I am keen to seen how you read in the data and also how you
> change the directory from which you are reading the image.
>

Changing directories is done with "os.chdir" (
http://docs.python.org/3/library/os.html#os.chdir).


> For the record this is not for homework but is a pet project of mine. I
> have already written a version of the program in Justbasic but python is
> faster. I am also interested in readers views as to which is the simplest
> and best way to achieve what I am trying to do.
>

Thanks for the clarification, btw. Good luck, as well.
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From rama29065 at gmail.com  Sun May  5 09:43:25 2013
From: rama29065 at gmail.com (rama29065 at gmail.com)
Date: Sun, 5 May 2013 06:43:25 -0700 (PDT)
Subject: Python not starting
Message-ID: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>

I was using python from over an year and half.Suddenly from yesterday i'm unable to run it.
The error is as follows
Traceback (most recent call last):
  File "C:\Python27\lib\site.py", line 563, in <module>
    main()
  File "C:\Python27\lib\site.py", line 546, in main
    known_paths = addsitepackages(known_paths)
  File "C:\Python27\lib\site.py", line 324, in addsitepackages
    if os.path.isdir(sitedir):
  File "C:\Python27\lib\genericpath.py", line 44, in isdir
    return stat.S_ISDIR(st.st_mode)
AttributeError: 'module' object has no attribute 'S_ISDIR'


From roy at panix.com  Sun May  5 09:51:59 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 05 May 2013 09:51:59 -0400
Subject: Python not starting
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
Message-ID: <roy-E16D26.09515805052013@news.panix.com>

In article <9ace60b8-a07d-41bc-ac9f-507f6c61f955 at googlegroups.com>,
 rama29065 at gmail.com wrote:

> I was using python from over an year and half.Suddenly from yesterday i'm 
> unable to run it.
> The error is as follows
> Traceback (most recent call last):
>   File "C:\Python27\lib\site.py", line 563, in <module>
>     main()
>   File "C:\Python27\lib\site.py", line 546, in main
>     known_paths = addsitepackages(known_paths)
>   File "C:\Python27\lib\site.py", line 324, in addsitepackages
>     if os.path.isdir(sitedir):
>   File "C:\Python27\lib\genericpath.py", line 44, in isdir
>     return stat.S_ISDIR(st.st_mode)
> AttributeError: 'module' object has no attribute 'S_ISDIR'

Just a wild guess, but did you happen to create a module of your own 
named "stat", which is getting imported instead of the one from the 
library?

Try doing:

>>> print stat.__file__

and see what it says.


From rama29065 at gmail.com  Sun May  5 10:00:05 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Sun, 5 May 2013 07:00:05 -0700 (PDT)
Subject: Python not starting
In-Reply-To: <roy-E16D26.09515805052013@news.panix.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
Message-ID: <c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>

On Sunday, May 5, 2013 7:21:59 PM UTC+5:30, Roy Smith wrote:
> In article <9ace60b8-a07d-41bc-ac9f-507f6c61f955 at googlegroups.com>,
> 
>  rama29065 at gmail.com wrote:
> 
> 
> 
> > I was using python from over an year and half.Suddenly from yesterday i'm 
> 
> > unable to run it.
> 
> > The error is as follows
> 
> > Traceback (most recent call last):
> 
> >   File "C:\Python27\lib\site.py", line 563, in <module>
> 
> >     main()
> 
> >   File "C:\Python27\lib\site.py", line 546, in main
> 
> >     known_paths = addsitepackages(known_paths)
> 
> >   File "C:\Python27\lib\site.py", line 324, in addsitepackages
> 
> >     if os.path.isdir(sitedir):
> 
> >   File "C:\Python27\lib\genericpath.py", line 44, in isdir
> 
> >     return stat.S_ISDIR(st.st_mode)
> 
> > AttributeError: 'module' object has no attribute 'S_ISDIR'
> 
> 
> 
> Just a wild guess, but did you happen to create a module of your own 
> 
> named "stat", which is getting imported instead of the one from the 
> 
> library?
> 
> 
> 
> Try doing:
> 
> 
> 
> >>> print stat.__file__
> 
> 
> 
> and see what it says.

Even from command prompt i can't start python.The error is coming up.Python in Windows7 box.


From roy at panix.com  Sun May  5 10:16:48 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 05 May 2013 10:16:48 -0400
Subject: Python not starting
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
Message-ID: <roy-AB6F78.10164805052013@news.panix.com>

> On Sunday, May 5, 2013 7:21:59 PM UTC+5:30, Roy Smith wrote:
> > In article <9ace60b8-a07d-41bc-ac9f-507f6c61f955 at googlegroups.com>,

> > Just a wild guess, but did you happen to create a module of your own 
> > named "stat", which is getting imported instead of the one from the 
> > library?

In article <c7c26e78-b786-4205-9ffa-5eb29006479c at googlegroups.com>,
 DRJ Reddy <rama29065 at gmail.com> wrote:
> Even from command prompt i can't start python.The error is coming up.Python 
> in Windows7 box.

I don't know Windows, but my guess is still that it's finding some other 
file called stat.py before it's finding the system library one.  Try 
doing a file system search for all files named "stat.py" and see what 
you find.  On unix, I would do "find / -name stat.py".  I assume there's 
something similar on Windows.

The other thing I would try is tracing the python process as it starts 
up.  On unix, I would do something like "strace -e trace=file python" 
and see if it's finding a stat.py in some unexpected place.  Again, I 
can only assume there's something similar on Windows.

Oh, and please don't post with Google Groups.  It double-spaces 
everything and makes your message really difficult to read.


From rama29065 at gmail.com  Sun May  5 10:28:42 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Sun, 5 May 2013 07:28:42 -0700 (PDT)
Subject: Python not starting
In-Reply-To: <roy-AB6F78.10164805052013@news.panix.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<roy-AB6F78.10164805052013@news.panix.com>
Message-ID: <5f96a641-d12e-4974-9de5-7e36a63f1238@googlegroups.com>

On Sunday, May 5, 2013 7:46:48 PM UTC+5:30, Roy Smith wrote:
> > On Sunday, May 5, 2013 7:21:59 PM UTC+5:30, Roy Smith wrote:
> 
> > > In article <9ace60b8-a07d-41bc-ac9f-507f6c61f955 at googlegroups.com>,
> 
> 
> 
> > > Just a wild guess, but did you happen to create a module of your own 
> 
> > > named "stat", which is getting imported instead of the one from the 
> 
> > > library?
> 
> 
> 
> In article <c7c26e78-b786-4205-9ffa-5eb29006479c at googlegroups.com>,
> 
>  DRJ Reddy <rama29065 at gmail.com> wrote:
> 
> > Even from command prompt i can't start python.The error is coming up.Python 
> 
> > in Windows7 box.
> 
> 
> 
> I don't know Windows, but my guess is still that it's finding some other 
> 
> file called stat.py before it's finding the system library one.  Try 
> 
> doing a file system search for all files named "stat.py" and see what 
> 
> you find.  On unix, I would do "find / -name stat.py".  I assume there's 
> 
> something similar on Windows.
> 
> 
> 
> The other thing I would try is tracing the python process as it starts 
> 
> up.  On unix, I would do something like "strace -e trace=file python" 
> 
> and see if it's finding a stat.py in some unexpected place.  Again, I 
> 
> can only assume there's something similar on Windows.
> 
> 
> 
> Oh, and please don't post with Google Groups.  It double-spaces 
> 
> everything and makes your message really difficult to read.

I found a stat.py in python27/idlelib i haven't created one.


From rosuav at gmail.com  Sun May  5 11:00:59 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 01:00:59 +1000
Subject: Python not starting
In-Reply-To: <roy-AB6F78.10164805052013@news.panix.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<roy-AB6F78.10164805052013@news.panix.com>
Message-ID: <CAPTjJmqGxhrs4T+W2bXReggtzQXHs=pmVsHKF+HsMZ1MxSeNog@mail.gmail.com>

On Mon, May 6, 2013 at 12:16 AM, Roy Smith <roy at panix.com> wrote:
> In article <c7c26e78-b786-4205-9ffa-5eb29006479c at googlegroups.com>,
>  DRJ Reddy <rama29065 at gmail.com> wrote:
>> Even from command prompt i can't start python.The error is coming up.Python
>> in Windows7 box.
>
> I don't know Windows, but my guess is still that it's finding some other
> file called stat.py before it's finding the system library one.  Try
> doing a file system search for all files named "stat.py" and see what
> you find.  On unix, I would do "find / -name stat.py".  I assume there's
> something similar on Windows.

Or alternatively, disable site.py by invoking python -S, and then
manually import stat and see what its file is.

ChrisA


From rama29065 at gmail.com  Sun May  5 11:11:45 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Sun, 5 May 2013 08:11:45 -0700 (PDT)
Subject: Python not starting
In-Reply-To: <mailman.1292.1367766068.3114.python-list@python.org>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<roy-AB6F78.10164805052013@news.panix.com>
	<mailman.1292.1367766068.3114.python-list@python.org>
Message-ID: <b8f7c4fe-2947-4143-b05d-5c1aedaebbf6@googlegroups.com>

On Sunday, May 5, 2013 8:30:59 PM UTC+5:30, Chris Angelico wrote:
> On Mon, May 6, 2013 at 12:16 AM, Roy Smith <roy at panix.com> wrote:
> 
> > In article <c7c26e78-b786-4205-9ffa-5eb29006479c at googlegroups.com>,
> 
> >  DRJ Reddy <rama29065 at gmail.com> wrote:
> 
> >> Even from command prompt i can't start python.The error is coming up.Python
> 
> >> in Windows7 box.
> 
> >
> 
> > I don't know Windows, but my guess is still that it's finding some other
> 
> > file called stat.py before it's finding the system library one.  Try
> 
> > doing a file system search for all files named "stat.py" and see what
> 
> > you find.  On unix, I would do "find / -name stat.py".  I assume there's
> 
> > something similar on Windows.
> 
> 
> 
> Or alternatively, disable site.py by invoking python -S, and then
> 
> manually import stat and see what its file is.
> 
> 
> 
> ChrisA

Thanks all of you,i have done it,by disabling,but what is the permanent solution.How can i start python idle 


From rosuav at gmail.com  Sun May  5 11:20:52 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 01:20:52 +1000
Subject: Python not starting
In-Reply-To: <b8f7c4fe-2947-4143-b05d-5c1aedaebbf6@googlegroups.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<roy-AB6F78.10164805052013@news.panix.com>
	<mailman.1292.1367766068.3114.python-list@python.org>
	<b8f7c4fe-2947-4143-b05d-5c1aedaebbf6@googlegroups.com>
Message-ID: <CAPTjJmqX_bdPGYAfNz3+JuBbhHHW6iu07c71ObQiZBsHE0tSuw@mail.gmail.com>

On Mon, May 6, 2013 at 1:11 AM, DRJ Reddy <rama29065 at gmail.com> wrote:
> On Sunday, May 5, 2013 8:30:59 PM UTC+5:30, Chris Angelico wrote:
>> On Mon, May 6, 2013 at 12:16 AM, Roy Smith <roy at panix.com> wrote:
>>
>> > In article <c7c26e78-b786-4205-9ffa-5eb29006479c at googlegroups.com>,
>>
>> >  DRJ Reddy <rama29065 at gmail.com> wrote:
>>
>> >> Even from command prompt i can't start python.The error is coming up.Python
>>
>> >> in Windows7 box.
>>
>> >
>>
>> > I don't know Windows, but my guess is still that it's finding some other
>>
>> > file called stat.py before it's finding the system library one.  Try
>>
>> > doing a file system search for all files named "stat.py" and see what
>>
>> > you find.  On unix, I would do "find / -name stat.py".  I assume there's
>>
>> > something similar on Windows.
>>
>>
>>
>> Or alternatively, disable site.py by invoking python -S, and then
>>
>> manually import stat and see what its file is.
>>
>>
>>
>> ChrisA
>
> Thanks all of you,i have done it,by disabling,but what is the permanent solution.How can i start python idle

Here's the steps:

1) Start Python with the -S option. You have apparently figured this
part out. This should give you a working interactive Python.

2) Type:
import stat
stat.__file__

3) See what the file is that was named there. If you created it, you
now know the problem.

4) Read Mark Lawrence's signature.

This post adds nothing to what has already been said; it's just
coalescing the previously-given advice into exact steps.

ChrisA


From rama29065 at gmail.com  Sun May  5 12:25:13 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Sun, 5 May 2013 09:25:13 -0700 (PDT)
Subject: Python not starting
In-Reply-To: <mailman.1293.1367767261.3114.python-list@python.org>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<roy-AB6F78.10164805052013@news.panix.com>
	<mailman.1292.1367766068.3114.python-list@python.org>
	<b8f7c4fe-2947-4143-b05d-5c1aedaebbf6@googlegroups.com>
	<mailman.1293.1367767261.3114.python-list@python.org>
Message-ID: <55cf0585-eae9-48b9-8fd0-e599b48b9fb0@googlegroups.com>

Chris i have seen stat.__file__. It gives me 'C:\\Python27\\lib\\stat.pyc'. What should i do now.


From breamoreboy at yahoo.co.uk  Sun May  5 10:26:58 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 05 May 2013 15:26:58 +0100
Subject: Python not starting
In-Reply-To: <c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
Message-ID: <km5q7k$a0s$1@ger.gmane.org>

On 05/05/2013 15:00, DRJ Reddy wrote:
> On Sunday, May 5, 2013 7:21:59 PM UTC+5:30, Roy Smith wrote:
>> In article <9ace60b8-a07d-41bc-ac9f-507f6c61f955 at googlegroups.com>,
>>
>>   rama29065 at gmail.com wrote:
>>
>>> I was using python from over an year and half.Suddenly from yesterday i'm
>>> unable to run it.
>>> The error is as follows
>>
>>> Traceback (most recent call last):
>>>    File "C:\Python27\lib\site.py", line 563, in <module>
>>>      main()
>>>    File "C:\Python27\lib\site.py", line 546, in main
>>>      known_paths = addsitepackages(known_paths)
>>>    File "C:\Python27\lib\site.py", line 324, in addsitepackages
>>>      if os.path.isdir(sitedir):
>>>    File "C:\Python27\lib\genericpath.py", line 44, in isdir
>>>      return stat.S_ISDIR(st.st_mode)
>>> AttributeError: 'module' object has no attribute 'S_ISDIR'
>>
>> Just a wild guess, but did you happen to create a module of your own
>> named "stat", which is getting imported instead of the one from the
>> library?
>>
>> Try doing:
>>>>> print stat.__file__
>>
>> and see what it says.
>
> Even from command prompt i can't start python.The error is coming up.Python in Windows7 box.
>

Place the call to print stat.__file__ in the file genericpath.py 
immediately before the line that gives the attribute error.

Would you also be kind enough to read and use the guidance given in the 
link in my signature.  My eyesight is bad enough without parsing double 
spaced stuff courtesy of google groups, thanks.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From rama29065 at gmail.com  Sun May  5 10:32:19 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Sun, 5 May 2013 07:32:19 -0700 (PDT)
Subject: Python not starting
In-Reply-To: <mailman.1291.1367764041.3114.python-list@python.org>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<mailman.1291.1367764041.3114.python-list@python.org>
Message-ID: <9d2513ed-2738-4b6f-92af-82c1faa54da2@googlegroups.com>

On Sunday, May 5, 2013 7:56:58 PM UTC+5:30, Mark Lawrence wrote:
> On 05/05/2013 15:00, DRJ Reddy wrote:
> 
> > On Sunday, May 5, 2013 7:21:59 PM UTC+5:30, Roy Smith wrote:
> 
> >> In article <9ace60b8-a07d-41bc-ac9f-507f6c61f955 at googlegroups.com>,
> 
> >>
> 
> >>   rama29065 at gmail.com wrote:
> 
> >>
> 
> >>> I was using python from over an year and half.Suddenly from yesterday i'm
> 
> >>> unable to run it.
> 
> >>> The error is as follows
> 
> >>
> 
> >>> Traceback (most recent call last):
> 
> >>>    File "C:\Python27\lib\site.py", line 563, in <module>
> 
> >>>      main()
> 
> >>>    File "C:\Python27\lib\site.py", line 546, in main
> 
> >>>      known_paths = addsitepackages(known_paths)
> 
> >>>    File "C:\Python27\lib\site.py", line 324, in addsitepackages
> 
> >>>      if os.path.isdir(sitedir):
> 
> >>>    File "C:\Python27\lib\genericpath.py", line 44, in isdir
> 
> >>>      return stat.S_ISDIR(st.st_mode)
> 
> >>> AttributeError: 'module' object has no attribute 'S_ISDIR'
> 
> >>
> 
> >> Just a wild guess, but did you happen to create a module of your own
> 
> >> named "stat", which is getting imported instead of the one from the
> 
> >> library?
> 
> >>
> 
> >> Try doing:
> 
> >>>>> print stat.__file__
> 
> >>
> 
> >> and see what it says.
> 
> >
> 
> > Even from command prompt i can't start python.The error is coming up.Python in Windows7 box.
> 
> >
> 
> 
> 
> Place the call to print stat.__file__ in the file genericpath.py 
> 
> immediately before the line that gives the attribute error.
> 
> 
> 
> Would you also be kind enough to read and use the guidance given in the 
> 
> link in my signature.  My eyesight is bad enough without parsing double 
> 
> spaced stuff courtesy of google groups, thanks.
> 
> 
> 
> -- 
> 
> If you're using GoogleCrap??? please read this 
> 
> http://wiki.python.org/moin/GoogleGroupsPython.
> 
> 
> 
> Mark Lawrence

Sorry for double spaced stuff,how can i get rid of it.


From roy at panix.com  Sun May  5 13:55:54 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 05 May 2013 13:55:54 -0400
Subject: Python not starting
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<mailman.1291.1367764041.3114.python-list@python.org>
	<9d2513ed-2738-4b6f-92af-82c1faa54da2@googlegroups.com>
Message-ID: <roy-386FB8.13555405052013@news.panix.com>

In article <9d2513ed-2738-4b6f-92af-82c1faa54da2 at googlegroups.com>,
 DRJ Reddy <rama29065 at gmail.com> wrote:

> > If you're using GoogleCrap??? please read this 
> > 
> > http://wiki.python.org/moin/GoogleGroupsPython.
> > 
> > 
> > 
> > Mark Lawrence
> 
> Sorry for double spaced stuff,how can i get rid of it.

I don't mean to be disrespectful, but did you actually read the page you 
were asked to read?  It says, about halfway down the page, "You should 
remove the excess quoted blank lines before posting. There are several 
way to do this.", and then goes on to describe three different ways.


From rama29065 at gmail.com  Sun May  5 14:15:23 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Sun, 5 May 2013 11:15:23 -0700 (PDT)
Subject: Python not starting
In-Reply-To: <roy-386FB8.13555405052013@news.panix.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<mailman.1291.1367764041.3114.python-list@python.org>
	<9d2513ed-2738-4b6f-92af-82c1faa54da2@googlegroups.com>
	<roy-386FB8.13555405052013@news.panix.com>
Message-ID: <bbbd74a7-9047-4ceb-bbb2-f230d2a6eda8@googlegroups.com>

I did read and understood that while replying if > is there we will get a blank line unnecessarily.


From rosuav at gmail.com  Sun May  5 18:29:01 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 08:29:01 +1000
Subject: Python not starting
In-Reply-To: <bbbd74a7-9047-4ceb-bbb2-f230d2a6eda8@googlegroups.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<mailman.1291.1367764041.3114.python-list@python.org>
	<9d2513ed-2738-4b6f-92af-82c1faa54da2@googlegroups.com>
	<roy-386FB8.13555405052013@news.panix.com>
	<bbbd74a7-9047-4ceb-bbb2-f230d2a6eda8@googlegroups.com>
Message-ID: <CAPTjJmphqZiSKS2rRu9=KcnopyVq65yW8brVo+-S_ad88j=giw@mail.gmail.com>

On Mon, May 6, 2013 at 4:15 AM, DRJ Reddy <rama29065 at gmail.com> wrote:
> I did read and understood that while replying if > is there we will get a blank line unnecessarily.

If you read that page, you'll know that it does NOT advocate the total
elimination of quoted text, which is what you've now done. Please
don't. Your posts now lack any form of context.

ChrisA


From drjreddy7 at gmail.com  Sun May  5 23:15:08 2013
From: drjreddy7 at gmail.com (drjreddy7 at gmail.com)
Date: Sun, 5 May 2013 20:15:08 -0700 (PDT)
Subject: Python not starting
In-Reply-To: <mailman.1313.1367792950.3114.python-list@python.org>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<mailman.1291.1367764041.3114.python-list@python.org>
	<9d2513ed-2738-4b6f-92af-82c1faa54da2@googlegroups.com>
	<roy-386FB8.13555405052013@news.panix.com>
	<bbbd74a7-9047-4ceb-bbb2-f230d2a6eda8@googlegroups.com>
	<mailman.1313.1367792950.3114.python-list@python.org>
Message-ID: <80b237bb-7990-4c48-9060-ca3f957de4de@googlegroups.com>

On Monday, May 6, 2013 3:59:01 AM UTC+5:30, Chris Angelico wrote:
> On Mon, May 6, 2013 at 4:15 AM, DRJ Reddy <rama29065 at gmail.com> wrote:
> I did read and understood that while replying if > is there we will get a blank line unnecessarily.
> If you read that page, you'll know that it does NOT advocate the total
> elimination of quoted text, which is what you've now done. Please
> don't. Your posts now lack any form of context.
> ChrisA

Sorry ChrisA,not only him for all, for the mess i have created.It was the first time for me on google groups. 
I am very happy to inform all of you that the problem is solved. The problem was due to the prescence of duplicates for genericpath.pyc and stat.pyc.I have deleted them and new ones were generated as i started python.
Thanking all of you for assisting me in solving the issue.


From rosuav at gmail.com  Mon May  6 00:02:31 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 14:02:31 +1000
Subject: Python not starting
In-Reply-To: <80b237bb-7990-4c48-9060-ca3f957de4de@googlegroups.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<mailman.1291.1367764041.3114.python-list@python.org>
	<9d2513ed-2738-4b6f-92af-82c1faa54da2@googlegroups.com>
	<roy-386FB8.13555405052013@news.panix.com>
	<bbbd74a7-9047-4ceb-bbb2-f230d2a6eda8@googlegroups.com>
	<mailman.1313.1367792950.3114.python-list@python.org>
	<80b237bb-7990-4c48-9060-ca3f957de4de@googlegroups.com>
Message-ID: <CAPTjJmrN4Gstr_UBVB=cqGKdzAU=Ao4oCVpTY9wnvDaX5dBjEA@mail.gmail.com>

On Mon, May 6, 2013 at 1:15 PM,  <drjreddy7 at gmail.com> wrote:
> On Monday, May 6, 2013 3:59:01 AM UTC+5:30, Chris Angelico wrote:
>> On Mon, May 6, 2013 at 4:15 AM, DRJ Reddy <rama29065 at gmail.com> wrote:
>> I did read and understood that while replying if > is there we will get a blank line unnecessarily.
>> If you read that page, you'll know that it does NOT advocate the total
>> elimination of quoted text, which is what you've now done. Please
>> don't. Your posts now lack any form of context.
>> ChrisA
>
> Sorry ChrisA,not only him for all, for the mess i have created.It was the first time for me on google groups.
> I am very happy to inform all of you that the problem is solved. The problem was due to the prescence of duplicates for genericpath.pyc and stat.pyc.I have deleted them and new ones were generated as i started python.
> Thanking all of you for assisting me in solving the issue.

Excellent! Glad it's sorted.

The .pyc problem is, if I understand correctly, more permanently
solved in newer versions of Python. So this won't ever be an issue
again :)

ChrisA


From steve+comp.lang.python at pearwood.info  Mon May  6 02:06:07 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 06 May 2013 06:06:07 GMT
Subject: Python not starting
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<mailman.1291.1367764041.3114.python-list@python.org>
	<9d2513ed-2738-4b6f-92af-82c1faa54da2@googlegroups.com>
	<roy-386FB8.13555405052013@news.panix.com>
	<bbbd74a7-9047-4ceb-bbb2-f230d2a6eda8@googlegroups.com>
	<mailman.1313.1367792950.3114.python-list@python.org>
	<80b237bb-7990-4c48-9060-ca3f957de4de@googlegroups.com>
Message-ID: <5187484f$0$21747$c3e8da3$76491128@news.astraweb.com>

On Sun, 05 May 2013 20:15:08 -0700, drjreddy7 wrote:

> I am very happy to inform all of
> you that the problem is solved. The problem was due to the prescence of
> duplicates for genericpath.pyc and stat.pyc.I have deleted them and new
> ones were generated as i started python. Thanking all of you for
> assisting me in solving the issue.


Well, I'm glad it's sorted, but the solution raises as many questions as 
it answers.

How did you get duplicate genericpath.pyc and stat.pyc files?

If they were duplicates, why didn't they have the right code in them?

It's probably not worth spending any more time investigating, but it is 
still rather mysterious.


-- 
Steven


From rama29065 at gmail.com  Mon May  6 06:33:23 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Mon, 6 May 2013 03:33:23 -0700 (PDT)
Subject: Python not starting
In-Reply-To: <5187484f$0$21747$c3e8da3$76491128@news.astraweb.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<roy-E16D26.09515805052013@news.panix.com>
	<c7c26e78-b786-4205-9ffa-5eb29006479c@googlegroups.com>
	<mailman.1291.1367764041.3114.python-list@python.org>
	<9d2513ed-2738-4b6f-92af-82c1faa54da2@googlegroups.com>
	<roy-386FB8.13555405052013@news.panix.com>
	<bbbd74a7-9047-4ceb-bbb2-f230d2a6eda8@googlegroups.com>
	<mailman.1313.1367792950.3114.python-list@python.org>
	<80b237bb-7990-4c48-9060-ca3f957de4de@googlegroups.com>
	<5187484f$0$21747$c3e8da3$76491128@news.astraweb.com>
Message-ID: <66d5fd71-2f98-4206-9197-d30279e5a50f@googlegroups.com>

> How did you get duplicate genericpath.pyc and stat.pyc files?
> If they were duplicates, why didn't they have the right code in them?
> It's probably not worth spending any more time investigating, but it is  
> still rather mysterious.
> Steven

When i was running idle on 4th of May,some error came out saying Idle sub-process error i don't remember it correctly,but i wonder how my windows box kept both the files and always loaded the older one instead of new one :D.


From steve+comp.lang.python at pearwood.info  Sun May  5 14:55:49 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 05 May 2013 18:55:49 GMT
Subject: Python not starting
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
Message-ID: <5186ab34$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sun, 05 May 2013 06:43:25 -0700, rama29065 wrote:

> I was using python from over an year and half.Suddenly from yesterday
> i'm unable to run it. 

Well, the obvious question is, what did you do yesterday to change your 
system? Did you install any new packages? Run a Windows update? Delete 
some stuff? Something changed. What was it?


> The error is as follows
>
> Traceback (most recent call last):
>   File "C:\Python27\lib\site.py", line 563, in <module>
>     main()
>   File "C:\Python27\lib\site.py", line 546, in main
>     known_paths = addsitepackages(known_paths)
>   File "C:\Python27\lib\site.py", line 324, in addsitepackages
>     if os.path.isdir(sitedir):
>   File "C:\Python27\lib\genericpath.py", line 44, in isdir
>     return stat.S_ISDIR(st.st_mode)
> AttributeError: 'module' object has no attribute 'S_ISDIR'


This is a Python error, so Python is definitely starting. It's starting, 
hitting an error, and then failing with an exception.

Interestingly, the error is in os.path.isdir. The os module should be 
importing the ntpath module. The ntpath module tries to import _isdir 
from the nt module, and if that fails, falls back on genericpath.isdir. 
Which is what fails. So you have two problems:

- why is your nt module missing?

- why does genericpath.isdir fail?


Try running Python from the command line with the -S switch:


python -S


(you might need to use /S on Windows instead, I'm not sure.) Note that 
this is uppercase S, not lowercase. -S will disable the import of site.py 
module, which hopefully will then give you a prompt so you can run this:


import nt
print nt.__file__


which hopefully will show you have created a file called "nt.py" which is 
interfering with the actual nt file needed by Python. Get rid of that, 
and you should be right.



-- 
Steven


From bahamutzero8825 at gmail.com  Sun May  5 15:47:09 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Sun, 05 May 2013 14:47:09 -0500
Subject: Python not starting
In-Reply-To: <5186ab34$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<5186ab34$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <5186B73D.2050007@gmail.com>

On 2013.05.05 13:55, Steven D'Aprano wrote:
> (you might need to use /S on Windows instead, I'm not sure.)
That is only a convention among Microsoft's CLI utilities. Very few others follow it (even for programs written specifically for Windows),
and it is certainly not a necessity on Windows.
-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From drjreddy7 at gmail.com  Sun May  5 22:28:39 2013
From: drjreddy7 at gmail.com (drjreddy7 at gmail.com)
Date: Sun, 5 May 2013 19:28:39 -0700 (PDT)
Subject: Python not starting
In-Reply-To: <5186ab34$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <9ace60b8-a07d-41bc-ac9f-507f6c61f955@googlegroups.com>
	<5186ab34$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <a92a25eb-daca-4560-8d53-10f37afe0b88@googlegroups.com>


 import nt
 
 print nt.__file__
I have done above ones as you stated.
I'm getting an error
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute '__file__'


From jiang.adam at gmail.com  Sun May  5 12:00:54 2013
From: jiang.adam at gmail.com (Adam Jiang)
Date: Mon, 6 May 2013 01:00:54 +0900
Subject: How to avoid PEP8 'imported but unused'
Message-ID: <20130505160054.GA10521@capricorn>

I am new to python. Now, I am woring on an application within Django
framework. When I checked my code with pep8 and pyflakes, some warning
messages show up-'Foobar imported but unused'. Obviously, it indicates
that some modules are imprted to current module but never get
references. However, it seems the message is wrong in this case:

# file: urls.py
urlpattens = patterns(
    '',
    url('^signup/$', 'signup')
}

# file: register.py
def signup(request):
    return ...

# file: views.py
import signup from register

The warning message is shown in file views.py. It seems to me that the
code is okay because Django requires all functions serve as 'view' is
typically go into views.py. 'import' is about get 'signup' function
into module 'views.py'. Or, I am totally wrong? Is there a proper way
to avoid this warnning?

Best regards,
/Adam


From fabiosantosart at gmail.com  Sun May  5 12:18:40 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sun, 5 May 2013 17:18:40 +0100
Subject: How to avoid PEP8 'imported but unused'
In-Reply-To: <20130505160054.GA10521@capricorn>
References: <20130505160054.GA10521@capricorn>
Message-ID: <CAA=1kxT6M_wn7Ek+RAN9Zo1KJ7T4sMdDgDd4LC1CqaRJkToNqQ@mail.gmail.com>

I usually do this on pyflakes:

import whatever
assert whatever  # silence pyflakes

Pyflakes and pep8 have no way of knowing django will import and use your
module, or whether you are just importing a module for the side effects, so
they issue a warning anyway. Assert'ing counts as using the module, so it
counts as an used import.

On 5 May 2013 17:05, "Adam Jiang" <jiang.adam at gmail.com> wrote:
>
> I am new to python. Now, I am woring on an application within Django
> framework. When I checked my code with pep8 and pyflakes, some warning
> messages show up-'Foobar imported but unused'. Obviously, it indicates
> that some modules are imprted to current module but never get
> references. However, it seems the message is wrong in this case:
>
> # file: urls.py
> urlpattens = patterns(
>     '',
>     url('^signup/$', 'signup')
> }
>
> # file: register.py
> def signup(request):
>     return ...
>
> # file: views.py
> import signup from register
>
> The warning message is shown in file views.py. It seems to me that the
> code is okay because Django requires all functions serve as 'view' is
> typically go into views.py. 'import' is about get 'signup' function
> into module 'views.py'. Or, I am totally wrong? Is there a proper way
> to avoid this warnning?
>
> Best regards,
> /Adam
> --
> http://mail.python.org/mailman/listinfo/python-list
-------------- next part --------------
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From jiang.adam at gmail.com  Sun May  5 12:40:31 2013
From: jiang.adam at gmail.com (Adam Jiang)
Date: Mon, 6 May 2013 01:40:31 +0900
Subject: How to avoid PEP8 'imported but unused'
In-Reply-To: <CAA=1kxT6M_wn7Ek+RAN9Zo1KJ7T4sMdDgDd4LC1CqaRJkToNqQ@mail.gmail.com>
References: <20130505160054.GA10521@capricorn>
	<CAA=1kxT6M_wn7Ek+RAN9Zo1KJ7T4sMdDgDd4LC1CqaRJkToNqQ@mail.gmail.com>
Message-ID: <20130505164030.GA12637@capricorn>

Thanks. It works very well.

One more question. In this particular case it seems 'assert' should be
safe as a workaround, doesn't it?  'assert' will check if the symbol
is imported and not NULL. Is there side effect if I just applied this
rule as a generic one.

/Adam
On Sun, May 05, 2013 at 05:18:40PM +0100, F?bio Santos wrote:
> I usually do this on pyflakes:
> 
> import whatever
> assert whatever? # silence pyflakes
> 
> Pyflakes and pep8 have no way of knowing django will import and use your
> module, or whether you are just importing a module for the side effects, so
> they issue a warning anyway. Assert'ing counts as using the module, so it
> counts as an used import.
> 
> On 5 May 2013 17:05, "Adam Jiang" <jiang.adam at gmail.com> wrote:
> >
> > I am new to python. Now, I am woring on an application within Django
> > framework. When I checked my code with pep8 and pyflakes, some warning
> > messages show up-'Foobar imported but unused'. Obviously, it indicates
> > that some modules are imprted to current module but never get
> > references. However, it seems the message is wrong in this case:
> >
> > # file: urls.py
> > urlpattens = patterns(
> > ? ? '',
> > ? ? url('^signup/$', 'signup')
> > }
> >
> > # file: register.py
> > def signup(request):
> > ? ? return ...
> >
> > # file: views.py
> > import signup from register
> >
> > The warning message is shown in file views.py. It seems to me that the
> > code is okay because Django requires all functions serve as 'view' is
> > typically go into views.py. 'import' is about get 'signup' function
> > into module 'views.py'. Or, I am totally wrong? Is there a proper way
> > to avoid this warnning?
> >
> > Best regards,
> > /Adam
> > --
> > http://mail.python.org/mailman/listinfo/python-list
> 


From fabiosantosart at gmail.com  Sun May  5 13:27:44 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sun, 5 May 2013 18:27:44 +0100
Subject: How to avoid PEP8 'imported but unused'
In-Reply-To: <20130505164030.GA12637@capricorn>
References: <20130505160054.GA10521@capricorn>
	<CAA=1kxT6M_wn7Ek+RAN9Zo1KJ7T4sMdDgDd4LC1CqaRJkToNqQ@mail.gmail.com>
	<20130505164030.GA12637@capricorn>
Message-ID: <CAA=1kxRS5P0UZnsUeFwq_W397sj-oB6oX-oOj5Fzy9HDse3=UA@mail.gmail.com>

That assert will never fail. If the symbol is not imported, the import
statement raises ImportError. And actually "assert" makes sure that
the value is not false-ish, not None/Null. And AFAIK a module object
is *always* true.

> One more question. In this particular case it seems 'assert' should be
> safe as a workaround, doesn't it?  'assert' will check if the symbol
> is imported and not NULL. Is there side effect if I just applied this
> rule as a generic one.
>

--
F?bio Santos


From jiang.adam at gmail.com  Sun May  5 22:47:57 2013
From: jiang.adam at gmail.com (Adam Jiang)
Date: Mon, 6 May 2013 11:47:57 +0900
Subject: How to avoid PEP8 'imported but unused'
In-Reply-To: <CAA=1kxRS5P0UZnsUeFwq_W397sj-oB6oX-oOj5Fzy9HDse3=UA@mail.gmail.com>
References: <20130505160054.GA10521@capricorn>
	<CAA=1kxT6M_wn7Ek+RAN9Zo1KJ7T4sMdDgDd4LC1CqaRJkToNqQ@mail.gmail.com>
	<20130505164030.GA12637@capricorn>
	<CAA=1kxRS5P0UZnsUeFwq_W397sj-oB6oX-oOj5Fzy9HDse3=UA@mail.gmail.com>
Message-ID: <20130506024757.GA18201@capricorn>

Thank you. Problem solved.

/Adam
On Sun, May 05, 2013 at 06:27:44PM +0100, F?bio Santos wrote:
> That assert will never fail. If the symbol is not imported, the import
> statement raises ImportError. And actually "assert" makes sure that
> the value is not false-ish, not None/Null. And AFAIK a module object
> is *always* true.
> 
> > One more question. In this particular case it seems 'assert' should be
> > safe as a workaround, doesn't it?  'assert' will check if the symbol
> > is imported and not NULL. Is there side effect if I just applied this
> > rule as a generic one.
> >
> 
> --
> F?bio Santos


From python at mrabarnett.plus.com  Sun May  5 12:21:36 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 05 May 2013 17:21:36 +0100
Subject: How to avoid PEP8 'imported but unused'
In-Reply-To: <20130505160054.GA10521@capricorn>
References: <20130505160054.GA10521@capricorn>
Message-ID: <51868710.1070000@mrabarnett.plus.com>

On 05/05/2013 17:00, Adam Jiang wrote:
> I am new to python. Now, I am woring on an application within Django
> framework. When I checked my code with pep8 and pyflakes, some warning
> messages show up-'Foobar imported but unused'. Obviously, it indicates
> that some modules are imprted to current module but never get
> references. However, it seems the message is wrong in this case:
>
> # file: urls.py
> urlpattens = patterns(
>      '',
>      url('^signup/$', 'signup')
> }
>
> # file: register.py
> def signup(request):
>      return ...
>
> # file: views.py
> import signup from register
>
> The warning message is shown in file views.py. It seems to me that the
> code is okay because Django requires all functions serve as 'view' is
> typically go into views.py. 'import' is about get 'signup' function
> into module 'views.py'. Or, I am totally wrong? Is there a proper way
> to avoid this warnning?
>
It's not:

import signup from register

(that's an error) but:

from register import signup

After fixing that, does it still show the warning?



From __peter__ at web.de  Sun May  5 12:38:46 2013
From: __peter__ at web.de (Peter Otten)
Date: Sun, 05 May 2013 18:38:46 +0200
Subject: How to avoid PEP8 'imported but unused'
References: <20130505160054.GA10521@capricorn>
Message-ID: <km61u9$f40$1@ger.gmane.org>

Adam Jiang wrote:

> I am new to python. Now, I am woring on an application within Django
> framework. When I checked my code with pep8 and pyflakes, some warning
> messages show up-'Foobar imported but unused'. Obviously, it indicates
> that some modules are imprted to current module but never get
> references. However, it seems the message is wrong in this case:
> 
> # file: urls.py
> urlpattens = patterns(
>     '',
>     url('^signup/$', 'signup')
> }
> 
> # file: register.py
> def signup(request):
>     return ...
> 
> # file: views.py
> import signup from register
> 
> The warning message is shown in file views.py. It seems to me that the
> code is okay because Django requires all functions serve as 'view' is
> typically go into views.py. 'import' is about get 'signup' function
> into module 'views.py'. Or, I am totally wrong? Is there a proper way
> to avoid this warnning?

pylint has a way to suppress such warnings with a comment like

from signup import register # pylint:disable=W0611

but personally I find the magic comment more annoying than the false 
warning...



From l.selmi at icloud.com  Sun May  5 12:08:47 2013
From: l.selmi at icloud.com (leonardo selmi)
Date: Sun, 05 May 2013 18:08:47 +0200
Subject: learning python
Message-ID: <A5BD82FD-8558-4C89-8163-98A7DD12D81E@icloud.com>

hi guys

i need to find a good book to learn python with exercises and solutions, any suggestions?

thanks!

best regards

leonardo
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From rama29065 at gmail.com  Sun May  5 12:28:25 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Sun, 5 May 2013 09:28:25 -0700 (PDT)
Subject: learning python
In-Reply-To: <mailman.1295.1367770142.3114.python-list@python.org>
References: <mailman.1295.1367770142.3114.python-list@python.org>
Message-ID: <d50c88e0-5a50-46ca-9a79-b870f367cf2e@googlegroups.com>

A byte of python with learning python by Mark Lutz is a good combination.


From brunson at brunson.com  Sun May  5 12:58:22 2013
From: brunson at brunson.com (Eric Brunson)
Date: Sun, 05 May 2013 10:58:22 -0600
Subject: [Python-Help] learning python
In-Reply-To: <A5BD82FD-8558-4C89-8163-98A7DD12D81E@icloud.com>
References: <A5BD82FD-8558-4C89-8163-98A7DD12D81E@icloud.com>
Message-ID: <51868FAE.1090301@brunson.com>

On 05/05/2013 10:08 AM, leonardo selmi wrote:
> hi guys
>
> i need to find a good book to learn python with exercises and 
> solutions, any suggestions?
>
> thanks!
>

Leonardo,

There are several good online tutorials available, many listed here:  
http://wiki.python.org/moin/BeginnersGuide

There is also the Python Tutorial written by the creator of Python 
here:  http://docs.python.org/2/tutorial/index.html

If you want a hands on approach with exercises, try Learn Python the 
Hard Way:  http://learnpythonthehardway.org/

If you already have a background in programming I find Dive Into Python 
to be an excellent introduction: http://www.diveintopython.net/ as well 
as Think Python: How to Think Like a Computer Scientist: 
http://www.greenteapress.com/thinkpython/html/

If you want something you can hold in your hand and has paper pages, I 
can recommend Learning Python by Mark Lutz: 
http://shop.oreilly.com/product/9780596158071.do followed by The Python 
Cookbook, by Alex Martelli and David Ascher: 
http://shop.oreilly.com/product/9780596001674.do

The Massachusetts Institute of Technology uses Python to teach their 
introduction to programming course which is available online (free) 
here: 
http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-00sc-introduction-to-computer-science-and-programming-spring-2011/index.htm

I hope that helps.

Sincerely,
e.


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From l.selmi at icloud.com  Sun May  5 13:10:32 2013
From: l.selmi at icloud.com (leonardo selmi)
Date: Sun, 05 May 2013 19:10:32 +0200
Subject: [Python-Help] learning python
In-Reply-To: <51868FAE.1090301@brunson.com>
References: <A5BD82FD-8558-4C89-8163-98A7DD12D81E@icloud.com>
	<51868FAE.1090301@brunson.com>
Message-ID: <E6B4868E-0468-49DA-B61E-08B57DAC8C06@icloud.com>

thanks!



Il giorno 05/mag/2013, alle ore 18:58, Eric Brunson <brunson at brunson.com> ha scritto:

> On 05/05/2013 10:08 AM, leonardo selmi wrote:
>> hi guys
>> 
>> i need to find a good book to learn python with exercises and solutions, any suggestions?
>> 
>> thanks!
>> 
> 
> Leonardo,
> 
> There are several good online tutorials available, many listed here:  http://wiki.python.org/moin/BeginnersGuide
> 
> There is also the Python Tutorial written by the creator of Python here:  http://docs.python.org/2/tutorial/index.html
> 
> If you want a hands on approach with exercises, try Learn Python the Hard Way:  http://learnpythonthehardway.org/
> 
> If you already have a background in programming I find Dive Into Python to be an excellent introduction:  http://www.diveintopython.net/ as well as Think Python: How to Think Like a Computer Scientist:  http://www.greenteapress.com/thinkpython/html/
> 
> If you want something you can hold in your hand and has paper pages, I can recommend Learning Python by Mark Lutz:  http://shop.oreilly.com/product/9780596158071.do followed by The Python Cookbook, by Alex Martelli and David Ascher:  http://shop.oreilly.com/product/9780596001674.do
> 
> The Massachusetts Institute of Technology uses Python to teach their introduction to programming course which is available online (free) here:  http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-00sc-introduction-to-computer-science-and-programming-spring-2011/index.htm
> 
> I hope that helps.
> 
> Sincerely,
> e.
> 
> 

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From hermanmu at gmail.com  Mon May  6 10:43:56 2013
From: hermanmu at gmail.com (Michael Herman)
Date: Mon, 6 May 2013 07:43:56 -0700
Subject: learning python
In-Reply-To: <A5BD82FD-8558-4C89-8163-98A7DD12D81E@icloud.com>
References: <A5BD82FD-8558-4C89-8163-98A7DD12D81E@icloud.com>
Message-ID: <CA+f8p+xm3sd6Jzj7WA66pdc6DFtjbmd+Qh8aCf=JenRJz=YO5Q@mail.gmail.com>

realpython.com - just launched

On Sun, May 5, 2013 at 9:08 AM, leonardo selmi <l.selmi at icloud.com> wrote:
> hi guys
>
> i need to find a good book to learn python with exercises and solutions, any
> suggestions?
>
> thanks!
>
> best regards
>
> leonardo
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>


From ignoramus16992 at NOSPAM.16992.invalid  Sun May  5 13:11:11 2013
From: ignoramus16992 at NOSPAM.16992.invalid (Ignoramus16992)
Date: Sun, 05 May 2013 12:11:11 -0500
Subject: Why do Perl programmers make more money than Python programmers
Message-ID: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>

According to CIO.com, Python programmers make only $83,000 per year,
while Perl programmers make $93,000 per year. 

http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11

I would like to know, what explains the discrepancy. 

Thank you!

i


From sbugaj at pixar.com  Sun May  5 13:32:01 2013
From: sbugaj at pixar.com (Stephan Vladimir Bugaj)
Date: Sun, 5 May 2013 10:32:01 -0700
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
Message-ID: <5B2FE106-9F37-4272-B62E-B2F07DF91D45@pixar.com>

Most likely more legacy Perl code in mission critical systems

S

Sent from my pocket UNIVAC.

On May 5, 2013, at 10:11 AM, Ignoramus16992 <ignoramus16992 at NOSPAM.16992.invalid> wrote:

> According to CIO.com, Python programmers make only $83,000 per year,
> while Perl programmers make $93,000 per year. 
> 
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
> 
> I would like to know, what explains the discrepancy. 
> 
> Thank you!
> 
> i
> -- 
> http://mail.python.org/mailman/listinfo/python-list


From fabiosantosart at gmail.com  Sun May  5 13:52:21 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sun, 5 May 2013 18:52:21 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <5B2FE106-9F37-4272-B62E-B2F07DF91D45@pixar.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5B2FE106-9F37-4272-B62E-B2F07DF91D45@pixar.com>
Message-ID: <CAA=1kxSc=NfxJyF0tBqg0wEDSKbfH_2hBk97vOv8YfQmfA0YjA@mail.gmail.com>

> Most likely more legacy Perl code in mission critical systems

Which is unfair because when Python is ever surpassed by an even
better language/technology then we get paid more to work Python and
not move the industry forward by moving to the new technology and
hacking on it.

--
F?bio Santos


From sbugaj at pixar.com  Sun May  5 13:33:19 2013
From: sbugaj at pixar.com (Stephan Vladimir Bugaj)
Date: Sun, 5 May 2013 10:33:19 -0700
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
Message-ID: <2C66876A-D362-4F8B-B6E1-DFB49FC2C494@pixar.com>

And seniority combined with annual cost of living raises, due to Perl being in use longer

S

Sent from my pocket UNIVAC.

On May 5, 2013, at 10:11 AM, Ignoramus16992 <ignoramus16992 at NOSPAM.16992.invalid> wrote:

> According to CIO.com, Python programmers make only $83,000 per year,
> while Perl programmers make $93,000 per year. 
> 
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
> 
> I would like to know, what explains the discrepancy. 
> 
> Thank you!
> 
> i
> -- 
> http://mail.python.org/mailman/listinfo/python-list


From fabiosantosart at gmail.com  Sun May  5 13:34:57 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sun, 5 May 2013 18:34:57 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
Message-ID: <CAA=1kxSx-Q16d05FQHyJ4zi4Ma5gcVsudv1G=+vxrDevQH_CsQ@mail.gmail.com>

I wouldn't touch perl code with a ten foot pole.

On the other hand, python is pleasing to the eye and easy to write,
read and modify.

This means that you can easily be replaced with someone else who also
knows python, so your company doesn't care much about paying you well
and keeping you there.

On Sun, May 5, 2013 at 6:11 PM, Ignoramus16992
<ignoramus16992 at nospam.16992.invalid> wrote:
> According to CIO.com, Python programmers make only $83,000 per year,
> while Perl programmers make $93,000 per year.
>
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
>
> I would like to know, what explains the discrepancy.
>
> Thank you!
>
> i
> --
> http://mail.python.org/mailman/listinfo/python-list



-- 
F?bio Santos


From rosuav at gmail.com  Sun May  5 13:35:14 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 03:35:14 +1000
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
Message-ID: <CAPTjJmrfn5HDTfDc7QUQHkMwHhKp-+mYOrqfQU4ea0OJuY4pSA@mail.gmail.com>

On Mon, May 6, 2013 at 3:11 AM, Ignoramus16992
<ignoramus16992 at nospam.16992.invalid> wrote:
> According to CIO.com, Python programmers make only $83,000 per year,
> while Perl programmers make $93,000 per year.
>
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
>
> I would like to know, what explains the discrepancy.
>
> Thank you!

Once, I was young and foolish too, and an ignoramus, just like you. [1]

There's a big problem with comparing statistical averages without any
indication of their spread. Suppose these are the salaries involved:

Perl = [15000, 30000, 80000, 100000, 143000, 190000]
Python = [15000, 30000, 80000, 100000, 190000]

That is, the guy who's making 143K a year didn't mention that he's
using Python. Voila! Your averages differ, yet statistically, there's
not a lot of difference. The best way to know how useful the averages
are is to look at the distribution, eg look at the difference between
the highest and lowest values, or the standard deviation of the
sample, or something of that sort. Without that, there's no way of
knowing whether a 10K difference is at all significant. I would posit
that, among salaries, it's meaningless.

ChrisA

[1] I don't know if you're trolling or not, so I'll give a serious
response. But I'm going to start with a quote from Emerald Isle.
http://diamond.boisestate.edu/gas/sullivan/emerald_isle/web_opera/ei14.html


From rustompmody at gmail.com  Sun May  5 13:35:29 2013
From: rustompmody at gmail.com (rusi)
Date: Sun, 5 May 2013 10:35:29 -0700 (PDT)
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
Message-ID: <217e90de-851c-4fbb-b04b-9e1c77710102@wg15g2000pbb.googlegroups.com>

On May 5, 10:11?pm, Ignoramus16992 <ignoramus16... at NOSPAM.
16992.invalid> wrote:
> According to CIO.com, Python programmers make only $83,000 per year,
> while Perl programmers make $93,000 per year.
>
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
>
> I would like to know, what explains the discrepancy.
>
> Thank you!
>
> i

I expect Cobol programmers earn more than either
Its called supply and demand


From breamoreboy at yahoo.co.uk  Sun May  5 14:24:34 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 05 May 2013 19:24:34 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <217e90de-851c-4fbb-b04b-9e1c77710102@wg15g2000pbb.googlegroups.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<217e90de-851c-4fbb-b04b-9e1c77710102@wg15g2000pbb.googlegroups.com>
Message-ID: <km6856$15t$2@ger.gmane.org>

On 05/05/2013 18:35, rusi wrote:
> On May 5, 10:11 pm, Ignoramus16992 <ignoramus16... at NOSPAM.
> 16992.invalid> wrote:
>> According to CIO.com, Python programmers make only $83,000 per year,
>> while Perl programmers make $93,000 per year.
>>
>> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
>>
>> I would like to know, what explains the discrepancy.
>>
>> Thank you!
>>
>> i
>
> I expect Cobol programmers earn more than either
> Its called supply and demand
>

They might get paid more, whether or not they earn it is an entirely 
different question.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From roy at panix.com  Sun May  5 13:58:51 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 05 May 2013 13:58:51 -0400
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
Message-ID: <roy-BEDAEA.13585105052013@news.panix.com>

In article <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d at giganews.com>,
 Ignoramus16992 <ignoramus16992 at NOSPAM.16992.invalid> wrote:

> According to CIO.com, Python programmers make only $83,000 per year,
> while Perl programmers make $93,000 per year. 

It's amazing the depths to which people are willing to sink for an extra 
$10k per year.


From steve+comp.lang.python at pearwood.info  Sun May  5 15:13:57 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 05 May 2013 19:13:57 GMT
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<roy-BEDAEA.13585105052013@news.panix.com>
Message-ID: <5186af75$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sun, 05 May 2013 13:58:51 -0400, Roy Smith wrote:

> In article <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d at giganews.com>,
>  Ignoramus16992 <ignoramus16992 at NOSPAM.16992.invalid> wrote:
> 
>> According to CIO.com, Python programmers make only $83,000 per year,
>> while Perl programmers make $93,000 per year.
> 
> It's amazing the depths to which people are willing to sink for an extra
> $10k per year.

Right now, I'd consider learning PHP for an extra $100 a month. Or 
peddling my arse down at the docks for twenty cents a time, which will be 
less embarrassing and much less painful.


-- 
Steven


From petite.abeille at gmail.com  Sun May  5 17:05:07 2013
From: petite.abeille at gmail.com (Petite Abeille)
Date: Sun, 5 May 2013 23:05:07 +0200
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <5186af75$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<roy-BEDAEA.13585105052013@news.panix.com>
	<5186af75$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <9B4DAC3C-70F9-4FD6-88B5-E13A4CFD60BA@gmail.com>


On May 5, 2013, at 9:13 PM, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> On Sun, 05 May 2013 13:58:51 -0400, Roy Smith wrote:
> 
>> In article <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d at giganews.com>,
>> Ignoramus16992 <ignoramus16992 at NOSPAM.16992.invalid> wrote:
>> 
>>> According to CIO.com, Python programmers make only $83,000 per year,
>>> while Perl programmers make $93,000 per year.
>> 
>> It's amazing the depths to which people are willing to sink for an extra
>> $10k per year.
> 
> Right now, I'd consider learning PHP for an extra $100 a month. Or 
> peddling my arse down at the docks for twenty cents a time, which will be 
> less embarrassing and much less painful.

I, for one, I'm glad to let the Pythonistas take the high road, while other, more, err, pragmatic types, take the dough. ching ching.

From roy at panix.com  Sun May  5 17:07:41 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 05 May 2013 17:07:41 -0400
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<roy-BEDAEA.13585105052013@news.panix.com>
	<5186af75$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-8410F0.17074105052013@news.panix.com>

In article <5186af75$0$29997$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
 
> Right now, I'd consider learning PHP for an extra $100 a month. Or 
> peddling my arse down at the docks for twenty cents a time, which will be 
> less embarrassing and much less painful.

Having spent the better part of a year doing one of those activities, 
I'm inclined to agree.

There *are* programming languages worse than PHP.  Have you ever tried 
britescript?


From roy at panix.com  Sun May  5 17:49:04 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 05 May 2013 17:49:04 -0400
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<roy-BEDAEA.13585105052013@news.panix.com>
	<5186af75$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-8410F0.17074105052013@news.panix.com>
	<mailman.1310.1367789840.3114.python-list@python.org>
Message-ID: <roy-70B5BB.17490405052013@news.panix.com>

In article <mailman.1310.1367789840.3114.python-list at python.org>,
 Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:

> On Sun, 05 May 2013 17:07:41 -0400, Roy Smith <roy at panix.com> declaimed
> the following in gmane.comp.python.general:
> 
> > In article <5186af75$0$29997$c3e8da3$5496439d at news.astraweb.com>,
> >  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> >  
> > > Right now, I'd consider learning PHP for an extra $100 a month. Or 
> > > peddling my arse down at the docks for twenty cents a time, which will be 
> > > less embarrassing and much less painful.
> > 
> > Having spent the better part of a year doing one of those activities, 
> > I'm inclined to agree.
> > 
> > There *are* programming languages worse than PHP.  Have you ever tried 
> > britescript?
> 
> 	Is that a toothpaste, kitchen cleaner, or device for doing gold-leaf
> illuminated manuscripts? <G>

It is a programming language.  It is what Roku apps are written in.


From m at rtij.nl.invlalid  Tue May  7 16:31:44 2013
From: m at rtij.nl.invlalid (Martijn Lievaart)
Date: Tue, 7 May 2013 22:31:44 +0200
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<roy-BEDAEA.13585105052013@news.panix.com>
	<5186af75$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-8410F0.17074105052013@news.panix.com>
Message-ID: <gu4o5a-4qg.ln1@news.rtij.nl>

On Sun, 05 May 2013 17:07:41 -0400, Roy Smith wrote:

> There *are* programming languages worse than PHP.  Have you ever tried
> britescript?

Have you tried MUMPS? :-)

M4




From wrw at mac.com  Tue May  7 17:02:54 2013
From: wrw at mac.com (William Ray Wing)
Date: Tue, 07 May 2013 17:02:54 -0400
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <gu4o5a-4qg.ln1@news.rtij.nl>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<roy-BEDAEA.13585105052013@news.panix.com>
	<5186af75$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-8410F0.17074105052013@news.panix.com>
	<gu4o5a-4qg.ln1@news.rtij.nl>
Message-ID: <43D5AAA3-6DCE-4AF9-A652-B9F2E28E7C8A@mac.com>

On May 7, 2013, at 4:31 PM, Martijn Lievaart <m at rtij.nl.invlalid> wrote:

> On Sun, 05 May 2013 17:07:41 -0400, Roy Smith wrote:
> 
>> There *are* programming languages worse than PHP.  Have you ever tried
>> britescript?
> 
> Have you tried MUMPS? :-)
> 
> M4
> 

Which one?  The original MUMPS (Massachusetts General Hospital Utility Multi-Programming System), or the one that came out of Europe in the '90s and stole the MUMPS name (MUltifrontal Massively Parallel sparse direct Solver)?

I used both the original and its baby brother FOCAL which, considering that they ran on DEC PDP-7 (MUMPS) and DEC PDP-8 (FOCAL) systems with as little as 4k words of 18-bit memory on the PDP-7 and 8-bit memory on the PDP-8 is pretty spectacular.  They should be forgiven for a somewhat constrained list of key words and operations. 

-Bill

From steve+comp.lang.python at pearwood.info  Sun May  5 15:10:47 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 05 May 2013 19:10:47 GMT
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
Message-ID: <5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sun, 05 May 2013 12:11:11 -0500, Ignoramus16992 wrote:

> According to CIO.com, Python programmers make only $83,000 per year,
> while Perl programmers make $93,000 per year.
> 
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
> http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
> 
> I would like to know, what explains the discrepancy.

Perl is much harder to use, so the average Perl programmer burns out 
after a few years and takes up a less stressful career, like going 
undercover in the Russian mob or the Taliban. So only the most dedicated, 
brilliant and extreme programmers last long enough to become a Perl 
expert, and consequently can demand higher pay, while any idiot can learn 
to program Python, as I have.

Also, Perl programmers are an unprincipled, devious bunch, always looking 
for an opportunity to blackmail their employers into paying them extra. 
Python programmers are a decent, law-abiding people with a strong moral 
code who would never stoop to the sort of things that Perl coders are 
proud of doing.



-- 
Steven


From jt at toerring.de  Sun May  5 16:37:19 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 5 May 2013 20:37:19 GMT
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <aunu7vFmripU1@mid.uni-berlin.de>

In comp.lang.python Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> On Sun, 05 May 2013 12:11:11 -0500, Ignoramus16992 wrote:

> > According to CIO.com, Python programmers make only $83,000 per year,
> > while Perl programmers make $93,000 per year.
> > 
> > http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
> > http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
> > 
> > I would like to know, what explains the discrepancy.

> Perl is much harder to use, so the average Perl programmer burns out 
> after a few years and takes up a less stressful career, like going 
> undercover in the Russian mob or the Taliban. So only the most dedicated, 
> brilliant and extreme programmers last long enough to become a Perl 
> expert, and consequently can demand higher pay, while any idiot can learn 
> to program Python, as I have.

> Also, Perl programmers are an unprincipled, devious bunch, always looking 
> for an opportunity to blackmail their employers into paying them extra. 
> Python programmers are a decent, law-abiding people with a strong moral 
> code who would never stoop to the sort of things that Perl coders are 
> proud of doing.

Now you got me badly worried, using both Perl and Python (and
other, unspeakable languages, but not VB I promise!) Will I
end up as a Python hacker for the mob or worse - or is there
a chance of redemption (perhaps after a few years in Guanta-
namo bay)? And should I, while it lasts, get the Perl or the
Python salary, or the mean or both combined? Got to consider
that when applying for my next job!

                             Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From rweikusat at mssgmbh.com  Sun May  5 17:09:09 2013
From: rweikusat at mssgmbh.com (Rainer Weikusat)
Date: Sun, 05 May 2013 22:09:09 +0100
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<aunu7vFmripU1@mid.uni-berlin.de>
Message-ID: <87a9o9b0cq.fsf@sapphire.mobileactivedefense.com>

jt at toerring.de (Jens Thoms Toerring) writes:
> In comp.lang.python Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>> On Sun, 05 May 2013 12:11:11 -0500, Ignoramus16992 wrote:
>
>> > According to CIO.com, Python programmers make only $83,000 per year,
>> > while Perl programmers make $93,000 per year.
>> > 
>> > http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
>> > http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
>> > 
>> > I would like to know, what explains the discrepancy.
>
>> Perl is much harder to use, so the average Perl programmer burns out 
>> after a few years and takes up a less stressful career, like going 
>> undercover in the Russian mob or the Taliban. So only the most dedicated, 
>> brilliant and extreme programmers last long enough to become a Perl 
>> expert, and consequently can demand higher pay, while any idiot can learn 
>> to program Python, as I have.
>
>> Also, Perl programmers are an unprincipled, devious bunch, always looking 
>> for an opportunity to blackmail their employers into paying them extra. 
>> Python programmers are a decent, law-abiding people with a strong moral 
>> code who would never stoop to the sort of things that Perl coders are 
>> proud of doing.
>
> Now you got me badly worried, using both Perl and Python (and
> other, unspeakable languages, but not VB I promise!) Will I
> end up as a Python hacker for the mob or worse

https://en.wikipedia.org/wiki/Strange_Case_of_Dr_Jekyll_and_Mr_Hyde

[SCNR]


From jt at toerring.de  Sun May  5 17:33:36 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 5 May 2013 21:33:36 GMT
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<aunu7vFmripU1@mid.uni-berlin.de>
	<87a9o9b0cq.fsf@sapphire.mobileactivedefense.com>
Message-ID: <auo1hgFmripU2@mid.uni-berlin.de>

In comp.lang.python Rainer Weikusat <rweikusat at mssgmbh.com> wrote:
> jt at toerring.de (Jens Thoms Toerring) writes:
> > In comp.lang.python Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> >> On Sun, 05 May 2013 12:11:11 -0500, Ignoramus16992 wrote:
> >
> >> > According to CIO.com, Python programmers make only $83,000 per year,
> >> > while Perl programmers make $93,000 per year.
> >> > 
> >> > http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
> >> > http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
> >> > 
> >> > I would like to know, what explains the discrepancy.
> >
> >> Perl is much harder to use, so the average Perl programmer burns out 
> >> after a few years and takes up a less stressful career, like going 
> >> undercover in the Russian mob or the Taliban. So only the most dedicated, 
> >> brilliant and extreme programmers last long enough to become a Perl 
> >> expert, and consequently can demand higher pay, while any idiot can learn 
> >> to program Python, as I have.
> >
> >> Also, Perl programmers are an unprincipled, devious bunch, always looking 
> >> for an opportunity to blackmail their employers into paying them extra. 
> >> Python programmers are a decent, law-abiding people with a strong moral 
> >> code who would never stoop to the sort of things that Perl coders are 
> >> proud of doing.
> >
> > Now you got me badly worried, using both Perl and Python (and
> > other, unspeakable languages, but not VB I promise!) Will I
> > end up as a Python hacker for the mob or worse

> https://en.wikipedia.org/wiki/Strange_Case_of_Dr_Jekyll_and_Mr_Hyde

> [SCNR]

Well, that didn't have a happy ending:-( Should have listened to
my parents when they told me again and again "Never use Perl, just
say no!". Seems I'm doomed - what's the proper way to apply for a
job with the mob?

-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From roy at panix.com  Sun May  5 17:35:51 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 05 May 2013 17:35:51 -0400
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<aunu7vFmripU1@mid.uni-berlin.de>
	<87a9o9b0cq.fsf@sapphire.mobileactivedefense.com>
	<auo1hgFmripU2@mid.uni-berlin.de>
Message-ID: <roy-23EA97.17355105052013@news.panix.com>

In article <auo1hgFmripU2 at mid.uni-berlin.de>,
 jt at toerring.de (Jens Thoms Toerring) wrote:

> Well, that didn't have a happy ending:-( Should have listened to
> my parents when they told me again and again "Never use Perl, just
> say no!". Seems I'm doomed - what's the proper way to apply for a
> job with the mob?

I don't think you apply.  If they want you, they'll find you.


From jt at toerring.de  Sun May  5 17:43:58 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 5 May 2013 21:43:58 GMT
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<aunu7vFmripU1@mid.uni-berlin.de>
	<87a9o9b0cq.fsf@sapphire.mobileactivedefense.com>
	<auo1hgFmripU2@mid.uni-berlin.de>
	<roy-23EA97.17355105052013@news.panix.com>
Message-ID: <auo24uFmripU3@mid.uni-berlin.de>

In comp.lang.python Roy Smith <roy at panix.com> wrote:
> In article <auo1hgFmripU2 at mid.uni-berlin.de>,
>  jt at toerring.de (Jens Thoms Toerring) wrote:

> > Well, that didn't have a happy ending:-( Should have listened to
> > my parents when they told me again and again "Never use Perl, just
> > say no!". Seems I'm doomed - what's the proper way to apply for a
> > job with the mob?

> I don't think you apply.  If they want you, they'll find you.

I see, that's what's called headhuntering, isn't it?

-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From rosuav at gmail.com  Sun May  5 18:24:51 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 08:24:51 +1000
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <87a9o9b0cq.fsf@sapphire.mobileactivedefense.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<aunu7vFmripU1@mid.uni-berlin.de>
	<87a9o9b0cq.fsf@sapphire.mobileactivedefense.com>
Message-ID: <CAPTjJmovCBhZmdVcWhbCo-idVWhMWx_VZuSvu3SNRDa72ifbtw@mail.gmail.com>

On Mon, May 6, 2013 at 7:09 AM, Rainer Weikusat <rweikusat at mssgmbh.com> wrote:
> jt at toerring.de (Jens Thoms Toerring) writes:
>> Now you got me badly worried, using both Perl and Python (and
>> other, unspeakable languages, but not VB I promise!) Will I
>> end up as a Python hacker for the mob or worse
>
> https://en.wikipedia.org/wiki/Strange_Case_of_Dr_Jekyll_and_Mr_Hyde

Ah, that would be me. Every night, I work on open source projects
written in good languages; but four days a week from 9:00 till 5:00 my
other nature takes over, and there is a struggle between the forces of
Good and Evil. The Evil side is strong, but even there the Good side
is not completely unheard; there are occasional times when I fight off
the PHP influence. (I'm still confident that we will eventually move
off PHP altogether. My boss reckons it'll never happen, but I can be
patient...)

ChrisA


From dihedral88888 at googlemail.com  Sun May  5 17:34:28 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Sun, 5 May 2013 14:34:28 -0700 (PDT)
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <b2106932-cc0d-495c-baa2-7e01499050d6@googlegroups.com>

Steven D'Aprano? 2013?5?6????UTC+8??3?10?47????
> On Sun, 05 May 2013 12:11:11 -0500, Ignoramus16992 wrote:
> 
> 
> 
> > According to CIO.com, Python programmers make only $83,000 per year,
> 
> > while Perl programmers make $93,000 per year.
> 
> > 
> 
> > http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide10
> 
> > http://www.cio.com/slideshow/detail/97819?source=ifwartcio#slide11
> 
> > 
> 
> > I would like to know, what explains the discrepancy.
> 
> 
> 
> Perl is much harder to use, so the average Perl programmer burns out 
> 
> after a few years and takes up a less stressful career, like going 
> 
> undercover in the Russian mob or the Taliban. So only the most dedicated, 
> 
> brilliant and extreme programmers last long enough to become a Perl 
> 
> expert, and consequently can demand higher pay, while any idiot can learn 
> 
> to program Python, as I have.
> 
> 
> 
> Also, Perl programmers are an unprincipled, devious bunch, always looking 
> 
> for an opportunity to blackmail their employers into paying them extra. 
> 
> Python programmers are a decent, law-abiding people with a strong moral 
> 
> code who would never stoop to the sort of things that Perl coders are 
> 
> proud of doing.
> 
> 
> 
> 
> 
> 
> 
> -- 
> 
> Steven


Some bosses just like the 1 to 5 liners  of the Perl style 
in some cryptic forms from villain Perl programmers.

I did see the same tricks in the Lisp or C/C++ before
but with extremely long fat source codes in tens of 
thousands of lines that could also pleased some managers 
or bosses.







From llanitedave at veawb.coop  Mon May  6 02:13:53 2013
From: llanitedave at veawb.coop (llanitedave)
Date: Sun, 5 May 2013 23:13:53 -0700 (PDT)
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>

On Sunday, May 5, 2013 12:10:47 PM UTC-7, Steven D'Aprano wrote:

> 
> 
> Also, Perl programmers are an unprincipled, devious bunch, always looking 
> 
> for an opportunity to blackmail their employers into paying them extra. 
> 
> Python programmers are a decent, law-abiding people with a strong moral 
> 
> code who would never stoop to the sort of things that Perl coders are 
> 
> proud of doing.
> 
>
> 
> -- 
> 
> Steven

And of course, the Python Programmer's moral code is only 80 characters wide.



From fabiosantosart at gmail.com  Mon May  6 02:28:36 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 6 May 2013 07:28:36 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
Message-ID: <CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>

> And of course, the Python Programmer's moral code is only 80 characters
wide.

No! Was it not seventy characters wide? Was I fooled my entire life?
-------------- next part --------------
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From rosuav at gmail.com  Mon May  6 03:30:33 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 17:30:33 +1000
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
Message-ID: <CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>

On Mon, May 6, 2013 at 4:28 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
>> And of course, the Python Programmer's moral code is only 80 characters
>> wide.
>
> No! Was it not seventy characters wide? Was I fooled my entire life?

Well you see, it was 70 bytes back in the Python 2 days (I'll defer to
Steven for data points earlier than that), but with Python 3, there
were two versions: one was 140 bytes representing 70 characters, the
other 280 bytes representing 70 characters. In Python 3.3, they were
merged, and a trivial amount of overhead added, so now it's 80 bytes
representing 70 characters. But you have an absolute guarantee that
it's correct now.

Of course, the entire code can be represented as a single int now. You
used to have to use a long.

ChrisA


From fabiosantosart at gmail.com  Mon May  6 03:49:54 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 6 May 2013 08:49:54 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
Message-ID: <CAA=1kxS7m7RjVb2dvjxcq8awOvU7HeB3BT_15f1d5_2cnhVa_A@mail.gmail.com>

On 6 May 2013 08:34, "Chris Angelico" <rosuav at gmail.com> wrote:
> Well you see, it was 70 bytes back in the Python 2 days (I'll defer to
> Steven for data points earlier than that), but with Python 3, there
> were two versions: one was 140 bytes representing 70 characters, the
> other 280 bytes representing 70 characters. In Python 3.3, they were
> merged, and a trivial amount of overhead added, so now it's 80 bytes
> representing 70 characters. But you have an absolute guarantee that
> it's correct now.
>
> Of course, the entire code can be represented as a single int now. You
> used to have to use a long.
>
> ChrisA
> --

Thanks. You have made my day.

I may rise the average pay of a Python programmer in Portugal. I have asked
for a raise back in December, and was told that it wouldn't happen before
this year. I have done well. I think I deserve better pay than a
supermarket employee now. I am sure that my efforts were appreciated and I
will be rewarded. I am being sarcastic.

The above paragraph wouldn't be true if I programmed in perl, c++ or lisp.
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From kliateni at gmail.com  Mon May  6 03:55:55 2013
From: kliateni at gmail.com (Karim)
Date: Mon, 06 May 2013 09:55:55 +0200
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <CAA=1kxS7m7RjVb2dvjxcq8awOvU7HeB3BT_15f1d5_2cnhVa_A@mail.gmail.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<CAA=1kxS7m7RjVb2dvjxcq8awOvU7HeB3BT_15f1d5_2cnhVa_A@mail.gmail.com>
Message-ID: <5187620B.3030106@gmail.com>

Le 06/05/2013 09:49, F?bio Santos a ?crit :
> have asked for a raise back in December, and was told that it wouldn't 
> happen before this year. I have done well. I think I deserve better 
> pay than a supermarket employee now. I am sure that my efforts were 
> appreciated and I will be rewarded. I am being sarc

Austerity for python programmers in Portugal !?

;o)


Karim


From fabiosantosart at gmail.com  Mon May  6 03:58:31 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 6 May 2013 08:58:31 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <5187620B.3030106@gmail.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<CAA=1kxS7m7RjVb2dvjxcq8awOvU7HeB3BT_15f1d5_2cnhVa_A@mail.gmail.com>
	<5187620B.3030106@gmail.com>
Message-ID: <CAA=1kxS3ONzSc8h47acpH4fKLdn3_tPTqzyrUJYp65HN6hP34g@mail.gmail.com>

On 6 May 2013 08:55, "Karim" <kliateni at gmail.com> wrote:
>
> Austerity for python programmers in Portugal !?

Actually, lack of a market. I can't seem to find any other job programming
python. It's all php, VB, c#, and I think there is some COBOL in there too.
But who knows. Maybe I'm looking in the wrong places.
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From rosuav at gmail.com  Mon May  6 04:02:25 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 18:02:25 +1000
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <CAA=1kxS7m7RjVb2dvjxcq8awOvU7HeB3BT_15f1d5_2cnhVa_A@mail.gmail.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<CAA=1kxS7m7RjVb2dvjxcq8awOvU7HeB3BT_15f1d5_2cnhVa_A@mail.gmail.com>
Message-ID: <CAPTjJmq5S=h_TvwNtgkJsDsEC9zs0TRPz-p_q4r2GDrTHd39AQ@mail.gmail.com>

On Mon, May 6, 2013 at 5:49 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
> I may rise the average pay of a Python programmer in Portugal. I have asked
> for a raise back in December, and was told that it wouldn't happen before
> this year. I have done well. I think I deserve better pay than a supermarket
> employee now. I am sure that my efforts were appreciated and I will be
> rewarded. I am being sarcastic.
>
> The above paragraph wouldn't be true if I programmed in perl, c++ or lisp.

I dunno, it depends more on where you work than what you work with.
I'm the top employee at my workplace and use C++, Pike, PHP,
Javascript, and bash, plus ancillaries like SQL... and my salary is
definitely on the low end. Why? Because I work for a startup. No doubt
Google or IBM would pay their top people way more than I'm getting,
but that's not something a little internet startup can afford. So I
bide my time :) Some day we'll be massively profitable... some day.
And if not, hey, I'm making enough to survive.

Of course, there's the whole thing of "how easy would it be to replace
you" too. If the only language you know is PHP, chances are you can be
replaced by any idiot straight out of secondary skool (sorry, that's
school_real_secondary now isn't it), but someone who speaks FORTRAN
and knows the bank's internal systems well enough to maintain them can
ask for whatever salary he likes and still be cheaper than finding a
replacement. But that expert FORTRAN programmer, if he quit his job
and went searching, would quite probably find himself at the lower end
again if he joined a small company.

ChrisA


From fabiosantosart at gmail.com  Mon May  6 05:00:54 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 6 May 2013 10:00:54 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <CAPTjJmq5S=h_TvwNtgkJsDsEC9zs0TRPz-p_q4r2GDrTHd39AQ@mail.gmail.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<CAA=1kxS7m7RjVb2dvjxcq8awOvU7HeB3BT_15f1d5_2cnhVa_A@mail.gmail.com>
	<CAPTjJmq5S=h_TvwNtgkJsDsEC9zs0TRPz-p_q4r2GDrTHd39AQ@mail.gmail.com>
Message-ID: <CAA=1kxQZYDa1tA3-_DK8Qfy0LbrXY2PQD9Vypfu-h++PaNtHfg@mail.gmail.com>

All good points. I should probably blame the smallness of my company aswell.
On 6 May 2013 09:11, "Chris Angelico" <rosuav at gmail.com> wrote:

> On Mon, May 6, 2013 at 5:49 PM, F?bio Santos <fabiosantosart at gmail.com>
> wrote:
> > I may rise the average pay of a Python programmer in Portugal. I have
> asked
> > for a raise back in December, and was told that it wouldn't happen before
> > this year. I have done well. I think I deserve better pay than a
> supermarket
> > employee now. I am sure that my efforts were appreciated and I will be
> > rewarded. I am being sarcastic.
> >
> > The above paragraph wouldn't be true if I programmed in perl, c++ or
> lisp.
>
> I dunno, it depends more on where you work than what you work with.
> I'm the top employee at my workplace and use C++, Pike, PHP,
> Javascript, and bash, plus ancillaries like SQL... and my salary is
> definitely on the low end. Why? Because I work for a startup. No doubt
> Google or IBM would pay their top people way more than I'm getting,
> but that's not something a little internet startup can afford. So I
> bide my time :) Some day we'll be massively profitable... some day.
> And if not, hey, I'm making enough to survive.
>
> Of course, there's the whole thing of "how easy would it be to replace
> you" too. If the only language you know is PHP, chances are you can be
> replaced by any idiot straight out of secondary skool (sorry, that's
> school_real_secondary now isn't it), but someone who speaks FORTRAN
> and knows the bank's internal systems well enough to maintain them can
> ask for whatever salary he likes and still be cheaper than finding a
> replacement. But that expert FORTRAN programmer, if he quit his job
> and went searching, would quite probably find himself at the lower end
> again if he joined a small company.
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From wxjmfauth at gmail.com  Tue May  7 09:22:47 2013
From: wxjmfauth at gmail.com (jmfauth)
Date: Tue, 7 May 2013 06:22:47 -0700 (PDT)
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
Message-ID: <f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>

On 6 mai, 09:49, F?bio Santos <fabiosantos... at gmail.com> wrote:
> On 6 May 2013 08:34, "Chris Angelico" <ros... at gmail.com> wrote:
>
> > Well you see, it was 70 bytes back in the Python 2 days (I'll defer to
> > Steven for data points earlier than that), but with Python 3, there
> > were two versions: one was 140 bytes representing 70 characters, the
> > other 280 bytes representing 70 characters. In Python 3.3, they were
> > merged, and a trivial amount of overhead added, so now it's 80 bytes
> > representing 70 characters. But you have an absolute guarantee that
> > it's correct now.
>
> > Of course, the entire code can be represented as a single int now. You
> > used to have to use a long.
>
> > ChrisA
> > --
>
> Thanks. You have made my day.
>
> I may rise the average pay of a Python programmer in Portugal. I have asked
> for a raise back in December, and was told that it wouldn't happen before
> this year. I have done well. I think I deserve better pay than a
> supermarket employee now. I am sure that my efforts were appreciated and I
> will be rewarded. I am being sarcastic.
>
> The above paragraph wouldn't be true if I programmed in perl, c++ or lisp.


-----


1) The memory gain for many of us (usually non ascii users)
just become irrelevant.

>>> sys.getsizeof('ma??')
41
>>> sys.getsizeof('abcd')
29

2) More critical, Py 3.3, just becomes non unicode compliant,
(eg European languages or "ascii" typographers !)

>>> import timeit
>>> timeit.timeit("'abcd'*1000 + 'a'")
2.186670111428325
>>> timeit.timeit("'abcd'*1000 + '?'")
2.9951699820528432
>>> timeit.timeit("'abcd'*1000 + '?'")
3.0036780444886233
>>> timeit.timeit("'abcd'*1000 + '?'")
3.004992278824048
>>> timeit.timeit("'ma??'*1000 + '?'")
3.231025618708202
>>> timeit.timeit("'ma??'*1000 + '?'")
3.215894398100758
>>> timeit.timeit("'ma??'*1000 + '?'")
3.224407974255655
>>> timeit.timeit("'ma??'*1000 + '?'")
3.2206342273566406
>>> timeit.timeit("'abcd'*1000 + '?'")
2.9914403449067777

3) Python is "pround" to cover the whole unicode range,
unfortunately it "breaks" the BMP range.
Small GvR exemple (ascii) from the the bug list,
but with non ascii characters.

# Py 3.2, all chars

>>> timeit.repeat("a = 'hundred'; 'x' in a")
[0.09087790617297742, 0.07456871885972305, 0.07449940353376405]
>>> timeit.repeat("a = 'ma?????'; 'x' in a")
[0.10088136800095526, 0.07488497003487282, 0.07497594640028638]


# Py 3.3 ascii and non ascii chars
>>> timeit.repeat("a = 'hundred'; 'x' in a")
[0.11426985953005442, 0.10040049292649655, 0.09920834808588097]
>>> timeit.repeat("a = 'ma?????'; '?' in a")
[0.2345595188256766, 0.21637172864154763, 0.2179096624382737]


There are plenty of good reasons to use Python. There are
also plenty of good reasons to not use (or now to drop)
Python and to realize that if you wish to process text
seriously, you are better served by using "corporate
products" or tools using Unicode properly.

jmf




From rosuav at gmail.com  Tue May  7 09:32:55 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 7 May 2013 23:32:55 +1000
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
Message-ID: <CAPTjJmpmVuTPrbvxe-Q-1-97O3eTAgFcc0dbhE10q15gmn+iYA@mail.gmail.com>

On Tue, May 7, 2013 at 11:22 PM, jmfauth <wxjmfauth at gmail.com> wrote:
> There are plenty of good reasons to use Python. There are
> also plenty of good reasons to not use (or now to drop)
> Python and to realize that if you wish to process text
> seriously, you are better served by using "corporate
> products" or tools using Unicode properly.

There are plenty of good reasons to use Python. One of them is the
laughs you can get any time jmf posts here. There are also plenty of
good reasons to drop Python. One of them is because corporate products
like Microsoft Visual Studio are inherently better specifically
because they cost you money, and there's no way that something you
paid nothing for can ever be as good as that. Plus, you get to write
code that works on only one platform, and that's really good. Finally,
moving off Python would mean you don't feel obliged to respond to jmf,
which will increase your productivity measurably.

ChrisA


From fabiosantosart at gmail.com  Tue May  7 09:35:05 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 7 May 2013 14:35:05 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
Message-ID: <CAA=1kxSphzMjas1N+NycoLhVnsQXapJsziNqPvQLuv2GQ3Bv4Q@mail.gmail.com>

>
>
> -----
>
>
> 1) The memory gain for many of us (usually non ascii users)
> just become irrelevant.
>
> >>> sys.getsizeof('ma??')
> 41
> >>> sys.getsizeof('abcd')
> 29
>
> 2) More critical, Py 3.3, just becomes non unicode compliant,
> (eg European languages or "ascii" typographers !)
>
> >>> import timeit
> >>> timeit.timeit("'abcd'*1000 + 'a'")
> 2.186670111428325
> >>> timeit.timeit("'abcd'*1000 + '?'")
> 2.9951699820528432
> >>> timeit.timeit("'abcd'*1000 + '?'")
> 3.0036780444886233
> >>> timeit.timeit("'abcd'*1000 + '?'")
> 3.004992278824048
> >>> timeit.timeit("'ma??'*1000 + '?'")
> 3.231025618708202
> >>> timeit.timeit("'ma??'*1000 + '?'")
> 3.215894398100758
> >>> timeit.timeit("'ma??'*1000 + '?'")
> 3.224407974255655
> >>> timeit.timeit("'ma??'*1000 + '?'")
> 3.2206342273566406
> >>> timeit.timeit("'abcd'*1000 + '?'")
> 2.9914403449067777
>
> 3) Python is "pround" to cover the whole unicode range,
> unfortunately it "breaks" the BMP range.
> Small GvR exemple (ascii) from the the bug list,
> but with non ascii characters.
>
> # Py 3.2, all chars
>
> >>> timeit.repeat("a = 'hundred'; 'x' in a")
> [0.09087790617297742, 0.07456871885972305, 0.07449940353376405]
> >>> timeit.repeat("a = 'ma?????'; 'x' in a")
> [0.10088136800095526, 0.07488497003487282, 0.07497594640028638]
>
>
> # Py 3.3 ascii and non ascii chars
> >>> timeit.repeat("a = 'hundred'; 'x' in a")
> [0.11426985953005442, 0.10040049292649655, 0.09920834808588097]
> >>> timeit.repeat("a = 'ma?????'; '?' in a")
> [0.2345595188256766, 0.21637172864154763, 0.2179096624382737]
>
>
> There are plenty of good reasons to use Python. There are
> also plenty of good reasons to not use (or now to drop)
> Python and to realize that if you wish to process text
> seriously, you are better served by using "corporate
> products" or tools using Unicode properly.
>
> jmf

This is so off-topic that, after reading this, I feel I have just returned
from the Moon.

OTOH, it would seem like you know the Portuguese word for apple, so I also
feel home.

I am so confused.
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From square.steve at gmail.com  Tue May  7 10:17:52 2013
From: square.steve at gmail.com (Steve Simmons)
Date: Tue, 07 May 2013 15:17:52 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <CAA=1kxSphzMjas1N+NycoLhVnsQXapJsziNqPvQLuv2GQ3Bv4Q@mail.gmail.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
	<CAA=1kxSphzMjas1N+NycoLhVnsQXapJsziNqPvQLuv2GQ3Bv4Q@mail.gmail.com>
Message-ID: <4a070992-b5bd-4889-ac9a-286806b4389c@email.android.com>

"F?bio Santos" <fabiosantosart at gmail.com> wrote:

>>
>>
>> -----
>>
>>
>> 1) The memory gain for many of us (usually non ascii users)
>> just become irrelevant.
>>
>> >>> sys.getsizeof('ma??')
>> 41
>> >>> sys.getsizeof('abcd')
>> 29
>>
>> 2) More critical, Py 3.3, just becomes non unicode compliant,
>> (eg European languages or "ascii" typographers !)
>>
>> >>> import timeit
>> >>> timeit.timeit("'abcd'*1000 + 'a'")
>> 2.186670111428325
>> >>> timeit.timeit("'abcd'*1000 + '?'")
>> 2.9951699820528432
>> >>> timeit.timeit("'abcd'*1000 + '?'")
>> 3.0036780444886233
>> >>> timeit.timeit("'abcd'*1000 + '?'")
>> 3.004992278824048
>> >>> timeit.timeit("'ma??'*1000 + '?'")
>> 3.231025618708202
>> >>> timeit.timeit("'ma??'*1000 + '?'")
>> 3.215894398100758
>> >>> timeit.timeit("'ma??'*1000 + '?'")
>> 3.224407974255655
>> >>> timeit.timeit("'ma??'*1000 + '?'")
>> 3.2206342273566406
>> >>> timeit.timeit("'abcd'*1000 + '?'")
>> 2.9914403449067777
>>
>> 3) Python is "pround" to cover the whole unicode range,
>> unfortunately it "breaks" the BMP range.
>> Small GvR exemple (ascii) from the the bug list,
>> but with non ascii characters.
>>
>> # Py 3.2, all chars
>>
>> >>> timeit.repeat("a = 'hundred'; 'x' in a")
>> [0.09087790617297742, 0.07456871885972305, 0.07449940353376405]
>> >>> timeit.repeat("a = 'ma?????'; 'x' in a")
>> [0.10088136800095526, 0.07488497003487282, 0.07497594640028638]
>>
>>
>> # Py 3.3 ascii and non ascii chars
>> >>> timeit.repeat("a = 'hundred'; 'x' in a")
>> [0.11426985953005442, 0.10040049292649655, 0.09920834808588097]
>> >>> timeit.repeat("a = 'ma?????'; '?' in a")
>> [0.2345595188256766, 0.21637172864154763, 0.2179096624382737]
>>
>>
>> There are plenty of good reasons to use Python. There are
>> also plenty of good reasons to not use (or now to drop)
>> Python and to realize that if you wish to process text
>> seriously, you are better served by using "corporate
>> products" or tools using Unicode properly.
>>
>> jmf
>
>This is so off-topic that, after reading this, I feel I have just
>returned
>from the Moon.
>
>OTOH, it would seem like you know the Portuguese word for apple, so I
>also
>feel home.
>
>I am so confused.
>
>
>------------------------------------------------------------------------
>
>-- 
>http://mail.python.org/mailman/listinfo/python-list

Good to see jmf finally comparing apples with apples :-) 

Sent from a Galaxy far far away
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From steve+comp.lang.python at pearwood.info  Tue May  7 23:06:02 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 08 May 2013 03:06:02 GMT
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
	<CAA=1kxSphzMjas1N+NycoLhVnsQXapJsziNqPvQLuv2GQ3Bv4Q@mail.gmail.com>
	<mailman.1412.1367936288.3114.python-list@python.org>
Message-ID: <5189c11a$0$11094$c3e8da3@news.astraweb.com>

On Tue, 07 May 2013 15:17:52 +0100, Steve Simmons wrote:

> Good to see jmf finally comparing apples with apples :-)

*groans*

Truly the terrible pun that the terrible hijacking deserves.



-- 
Steven


From tjreedy at udel.edu  Tue May  7 14:40:03 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Tue, 07 May 2013 14:40:03 -0400
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
Message-ID: <kmbhq2$g3m$1@ger.gmane.org>

On 5/7/2013 9:22 AM, jmfauth road forth on his dead hobbyhorse to hijack 
yet another thread:

> # Py 3.3 ascii and non ascii chars
>>>> timeit.repeat("a = 'hundred'; 'x' in a")
> [0.11426985953005442, 0.10040049292649655, 0.09920834808588097]
>>>> timeit.repeat("a = 'ma?????'; '?' in a")
> [0.2345595188256766, 0.21637172864154763, 0.2179096624382737]

Python 3.3 is a language. Languages do not have timings.
CPython 3.3.0 is an implementation compiled and run under a particular 
OS and hardware. With respect to Unicode timings, especially for 
find/replace, it is obsolete. On my Win7 machine with fresh debug builds 
from the current repository, I see these times.

Python 3.3.1+ (default, May  7 2013, 14:03:12) [MSC v.1600 32 bit (Int
 >>> from timeit import repeat
 >>> repeat("a = 'hundred'; 'x' in a")
[0.19007337649622968, 0.190116721780754, 0.1900149679567562]
 >>> repeat("a = 'ma?a???'; '?' in a")
[0.20568874581187716, 0.20568782357178053, 0.20577051776710914]

Python 3.4.0a0 (default:32067784f198, May  7 2013, 13:59:10) [MSC v.1600
 >>> from timeit import repeat
 >>> repeat("a = 'hundred'; 'x' in a")
[0.1708080882915779, 0.17062978853956826, 0.1706740560642051]
 >>> repeat("a = 'ma?a???'; '?' in a")
[0.17612111348809734, 0.17562925210324565, 0.17549245315558437]

Note 1: debug builds are slower than install builds, especially for 
microbenchmarks with trivial statements. My installed 3.3.1 on a 
different machine has timings of about .1 for the ascii test. It is 
slower for the non-ascii test because the latest improvements were made 
after 3.3.1 was released.

Note 2: 3.4 has additional improvements that speed up everything, so 
that the 3.4 non-ascii time is faster that even the 3.3 ascii time.

Terry




From dihedral88888 at googlemail.com  Tue May  7 16:41:58 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Tue, 7 May 2013 13:41:58 -0700 (PDT)
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <mailman.1409.1367933578.3114.python-list@python.org>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
	<mailman.1409.1367933578.3114.python-list@python.org>
Message-ID: <9fcf8320-a54a-43cb-9ded-0c8ee7e2c41c@googlegroups.com>

Chris Angelico? 2013?5?7????UTC+8??9?32?55????
> On Tue, May 7, 2013 at 11:22 PM, jmfauth <wxjmfauth at gmail.com> wrote:
> 
> > There are plenty of good reasons to use Python. There are
> 
> > also plenty of good reasons to not use (or now to drop)
> 
> > Python and to realize that if you wish to process text
> 
> > seriously, you are better served by using "corporate
> 
> > products" or tools using Unicode properly.
> 
> 
> 
> There are plenty of good reasons to use Python. One of them is the
> 
> laughs you can get any time jmf posts here. There are also plenty of
> 
> good reasons to drop Python. One of them is because corporate products
> 
> like Microsoft Visual Studio are inherently better specifically
> 
> because they cost you money, and there's no way that something you
> 
> paid nothing for can ever be as good as that. Plus, you get to write
> 
People used MS products  because most bosses did not  want to pay 
the prices of work stations,  the minis, or the main-frames and 
the salaries of the system  administrators  in 199x. 


> code that works on only one platform, and that's really good. Finally,
> 
> moving off Python would mean you don't feel obliged to respond to jmf,
> 
> which will increase your productivity measurably.
> 
> 
> 
> ChrisA

The price issue of a software  package or a platform is not 
the only  way to judge a programming language.


From walterhurry at lavabit.com  Tue May  7 17:14:08 2013
From: walterhurry at lavabit.com (Walter Hurry)
Date: Tue, 7 May 2013 21:14:08 +0000 (UTC)
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
	<mailman.1409.1367933578.3114.python-list@python.org>
Message-ID: <kmbqr0$90k$1@news.albasani.net>

On Tue, 07 May 2013 23:32:55 +1000, Chris Angelico wrote:

> On Tue, May 7, 2013 at 11:22 PM, jmfauth <wxjmfauth at gmail.com> wrote:
>> There are plenty of good reasons to use Python. There are also plenty
>> of good reasons to not use (or now to drop) Python and to realize that
>> if you wish to process text seriously, you are better served by using
>> "corporate products" or tools using Unicode properly.
> 
> There are plenty of good reasons to use Python. One of them is the
> laughs you can get any time jmf posts here. There are also plenty of
> good reasons to drop Python. One of them is because corporate products
> like Microsoft Visual Studio are inherently better specifically because
> they cost you money, and there's no way that something you paid nothing
> for can ever be as good as that. Plus, you get to write code that works
> on only one platform, and that's really good. Finally,
> moving off Python would mean you don't feel obliged to respond to jmf,
> which will increase your productivity measurably.

TMML. Thanks!



From nhodgson at iinet.net.au  Tue May  7 20:34:35 2013
From: nhodgson at iinet.net.au (Neil Hodgson)
Date: Wed, 08 May 2013 10:34:35 +1000
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
Message-ID: <BLydnddcgOYnAxTMnZ2dnUVZ_uSdnZ2d@westnet.com.au>

jmfauth:

> 2) More critical, Py 3.3, just becomes non unicode compliant,
> (eg European languages or "ascii" typographers !)
> ...

    This is not demonstrating non-compliance. It is comparing 
performance, not compliance.

    Please show an example where Python 3.3 is not compliant with Unicode.

    Neil


From benjamin.kaplan at case.edu  Tue May  7 21:11:26 2013
From: benjamin.kaplan at case.edu (Benjamin Kaplan)
Date: Tue, 7 May 2013 18:11:26 -0700
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <BLydnddcgOYnAxTMnZ2dnUVZ_uSdnZ2d@westnet.com.au>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
	<BLydnddcgOYnAxTMnZ2dnUVZ_uSdnZ2d@westnet.com.au>
Message-ID: <CAMuTYXgKrrns5R7Do7H-s4Yys8cLwVuwex-SqbcqSgy6Sgb=WA@mail.gmail.com>

On May 7, 2013 5:42 PM, "Neil Hodgson" <nhodgson at iinet.net.au> wrote:
>
> jmfauth:
>
>> 2) More critical, Py 3.3, just becomes non unicode compliant,
>> (eg European languages or "ascii" typographers !)
>> ...
>
>
>    This is not demonstrating non-compliance. It is comparing performance,
not compliance.
>
>    Please show an example where Python 3.3 is not compliant with Unicode.
>
>    Neil
> --
> http://mail.python.org/mailman/listinfo/python-list

It's violating page 1+1j of the Unicode spec, where it says precisely how
long each operation is allowed to take. Only wise people can see that page.
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From davea at davea.name  Tue May  7 21:23:21 2013
From: davea at davea.name (Dave Angel)
Date: Tue, 07 May 2013 21:23:21 -0400
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <CAMuTYXgKrrns5R7Do7H-s4Yys8cLwVuwex-SqbcqSgy6Sgb=WA@mail.gmail.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
	<BLydnddcgOYnAxTMnZ2dnUVZ_uSdnZ2d@westnet.com.au>
	<CAMuTYXgKrrns5R7Do7H-s4Yys8cLwVuwex-SqbcqSgy6Sgb=WA@mail.gmail.com>
Message-ID: <5189A909.8080306@davea.name>

On 05/07/2013 09:11 PM, Benjamin Kaplan wrote:
> On May 7, 2013 5:42 PM, "Neil Hodgson" <nhodgson at iinet.net.au> wrote:
>>
>> jmfauth:
>>
>>> 2) More critical, Py 3.3, just becomes non unicode compliant,
>>> (eg European languages or "ascii" typographers !)
>>> ...
>>
>>
>>     This is not demonstrating non-compliance. It is comparing performance,
> not compliance.
>>
>>     Please show an example where Python 3.3 is not compliant with Unicode.
>>
>>     Neil
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
> It's violating page 1+1j of the Unicode spec, where it says precisely how
> long each operation is allowed to take. Only wise people can see that page.
>
>
>
Of course!   It's a complex page.


-- 
DaveA


From breamoreboy at yahoo.co.uk  Tue May  7 21:22:50 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 08 May 2013 02:22:50 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <BLydnddcgOYnAxTMnZ2dnUVZ_uSdnZ2d@westnet.com.au>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
	<BLydnddcgOYnAxTMnZ2dnUVZ_uSdnZ2d@westnet.com.au>
Message-ID: <kmc9d9$on3$1@ger.gmane.org>

On 08/05/2013 01:34, Neil Hodgson wrote:
> jmfauth:
>
>> 2) More critical, Py 3.3, just becomes non unicode compliant,
>> (eg European languages or "ascii" typographers !)
>> ...
>
>     This is not demonstrating non-compliance. It is comparing
> performance, not compliance.
>
>     Please show an example where Python 3.3 is not compliant with Unicode.
>
>     Neil

Surely nobody expects an answer, although I suppose there is always a 
first time for everything.  Once again stealing from Tommy Docherty, 
jmfauth is to Python what King Herod was to baby sitting.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From rustompmody at gmail.com  Wed May  8 06:43:00 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 8 May 2013 03:43:00 -0700 (PDT)
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<CAPTjJmoF1CK661GDovgw0MmveOv-tAOGSW2odquM4eh7kei-eg@mail.gmail.com>
	<mailman.1320.1367826603.3114.python-list@python.org>
	<f6f88950-979d-4f6d-8265-310d73ae3a60@w15g2000vbn.googlegroups.com>
	<BLydnddcgOYnAxTMnZ2dnUVZ_uSdnZ2d@westnet.com.au>
	<mailman.1432.1367975873.3114.python-list@python.org>
Message-ID: <af6edac7-180a-4980-80eb-7078f631466c@qc10g2000pbb.googlegroups.com>

On May 8, 6:11?am, Benjamin Kaplan <benjamin.kap... at case.edu> wrote:
> On May 7, 2013 5:42 PM, "Neil Hodgson" <nhodg... at iinet.net.au> wrote:

> > jmfauth:
>
> >> 2) More critical, Py 3.3, just becomes non unicode compliant,
> >> (eg European languages or "ascii" typographers !)
> >> ...
>
> > ? ?This is not demonstrating non-compliance. It is comparing performance,
> not compliance.
>
> > ? ?Please show an example where Python 3.3 is not compliant with Unicode.
>
> > ? ?Neil
>
> It's violating page 1+1j of the Unicode spec, where it says precisely how
> long each operation is allowed to take. Only wise people can see that page.

Ha Ha! -- I infer some Harry Potter here!
[Boarding train at platform 7.3 ]


From steve+comp.lang.python at pearwood.info  Mon May  6 08:03:15 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 06 May 2013 12:03:15 GMT
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<mailman.1318.1367825442.3114.python-list@python.org>
Message-ID: <51879c03$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Mon, 06 May 2013 17:30:33 +1000, Chris Angelico wrote:

> On Mon, May 6, 2013 at 4:28 PM, F?bio Santos <fabiosantosart at gmail.com>
> wrote:
>>> And of course, the Python Programmer's moral code is only 80
>>> characters wide.
>>
>> No! Was it not seventy characters wide? Was I fooled my entire life?
> 
> Well you see, it was 70 bytes back in the Python 2 days (I'll defer to
> Steven for data points earlier than that),


You had bytes? You were lucky. When I were a lad, we used to have to 
program by punching holes in stone tablets with our head.


You-tell-young-people-this-today-and-they-don't-believe-you-ly y'rs,



-- 
Steven


From joshua.landau.ws at gmail.com  Mon May  6 12:04:30 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Mon, 6 May 2013 17:04:30 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <51879c03$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<CAA=1kxSQE2uCkgTQbr3cfmg4PFQEj=OcYpTi5F+Chd+j0Q8Tuw@mail.gmail.com>
	<mailman.1318.1367825442.3114.python-list@python.org>
	<51879c03$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAN1F8qXrgoqPAstu+pz37gMt10-hv_MUw44_2fuc8GkciCN8JA@mail.gmail.com>

On 6 May 2013 13:03, Steven D'Aprano
<steve+comp.lang.python at pearwood.info>wrote:

> On Mon, 06 May 2013 17:30:33 +1000, Chris Angelico wrote:
>
> > On Mon, May 6, 2013 at 4:28 PM, F?bio Santos <fabiosantosart at gmail.com>
> > wrote:
> >>> And of course, the Python Programmer's moral code is only 80
> >>> characters wide.
> >>
> >> No! Was it not seventy characters wide? Was I fooled my entire life?
> >
> > Well you see, it was 70 bytes back in the Python 2 days (I'll defer to
> > Steven for data points earlier than that),
>
>
> You had bytes? You were lucky. When I were a lad, we used to have to
> program by punching holes in stone tablets with our head.
>
>
> You-tell-young-people-this-today-and-they-don't-believe-you-ly y'rs,


I do have my doubts, yes.
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From roy at panix.com  Mon May  6 07:41:49 2013
From: roy at panix.com (Roy Smith)
Date: Mon, 06 May 2013 07:41:49 -0400
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<5186aeb6$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<af561505-fffe-4e2a-8446-35a98da6ded7@googlegroups.com>
	<mailman.1317.1367821725.3114.python-list@python.org>
Message-ID: <roy-2F30BA.07414806052013@news.panix.com>

In article <mailman.1317.1367821725.3114.python-list at python.org>,
 F?bio Santos <fabiosantosart at gmail.com> wrote:

> > And of course, the Python Programmer's moral code is only 80 characters
> wide.
> 
> No! Was it not seventy characters wide? Was I fooled my entire life?

The entire moral code in a semi-tweet.  How convenient.


From no.email at nospam.invalid  Sun May  5 17:16:17 2013
From: no.email at nospam.invalid (Paul Rubin)
Date: Sun, 05 May 2013 14:16:17 -0700
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
Message-ID: <7xehdlp1pa.fsf@ruckus.brouhaha.com>

Ignoramus16992 <ignoramus16992 at NOSPAM.16992.invalid> writes:
> I would like to know, what explains the discrepancy. 

I see "New York" listed as a location for Perl but not for Python.  That
implies: 1) some general skew because of the very high cost of living in
NY (even compared to San Francisco or Silicon Valley); 2) further skew
because a good chuck of the NY programming jobs are in the financial
sector, which shovels money around with heavy farm equipment (but is
reportedly otherwise unpleasant to work in).  Wall Street has done very
well in the past few years, and some of that shows up as bonuses for the
involved parties.

I remember seeing a ridiculously high figure listed for Haskell, and
then realized the reason for it was similar to the above.  Most Haskell
programmers I know can't actually get Haskell jobs.


From no.email at nospam.invalid  Sun May  5 17:17:35 2013
From: no.email at nospam.invalid (Paul Rubin)
Date: Sun, 05 May 2013 14:17:35 -0700
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<7xehdlp1pa.fsf@ruckus.brouhaha.com>
Message-ID: <7xa9o9p1n4.fsf@ruckus.brouhaha.com>

Paul Rubin <no.email at nospam.invalid> writes:
> I see "New York" listed as a location for Perl but not for Python.

Whaat?  It's there for Python, though in the #3 position rather than #2.
I must have flipped through the slides too fast.


From ignoramus16992 at NOSPAM.16992.invalid  Sun May  5 19:05:40 2013
From: ignoramus16992 at NOSPAM.16992.invalid (Ignoramus16992)
Date: Sun, 05 May 2013 18:05:40 -0500
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<7xehdlp1pa.fsf@ruckus.brouhaha.com>
	<7xa9o9p1n4.fsf@ruckus.brouhaha.com>
Message-ID: <17idnc73z7tZeBvMnZ2dnUVZ_vWdnZ2d@giganews.com>

On 2013-05-05, Paul Rubin <no.email at nospam.invalid> wrote:
> Paul Rubin <no.email at nospam.invalid> writes:
>> I see "New York" listed as a location for Perl but not for Python.
>
> Whaat?  It's there for Python, though in the #3 position rather than #2.
> I must have flipped through the slides too fast.

My website algebra.com is written in perl, it is now #1,198 in the US
rankings, based on Quantcast.  I could not be happier with
maintainability and robustness features of perl. 

i
going undercover for the russian mob next week


From news at lawshouse.org  Mon May  6 02:07:12 2013
From: news at lawshouse.org (Henry Law)
Date: Mon, 06 May 2013 07:07:12 +0100
Subject: Why do Perl programmers make more money than Python programmers
In-Reply-To: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
Message-ID: <McednZh6_OMN1RrMnZ2dnUVZ8hmdnZ2d@giganews.com>

On 05/05/13 18:11, Ignoramus16992 wrote:
> According to CIO.com

What an amusing thread; lightened my (non-programmer) day.

-- 

Henry Law            Manchester, England


From ignoramus30465 at NOSPAM.30465.invalid  Mon May  6 21:53:13 2013
From: ignoramus30465 at NOSPAM.30465.invalid (Ignoramus30465)
Date: Mon, 06 May 2013 20:53:13 -0500
Subject: Why do Perl programmers make more money than Python programmers
References: <zrOdnZU2U6syDxvMnZ2dnUVZ_v2dnZ2d@giganews.com>
	<McednZh6_OMN1RrMnZ2dnUVZ8hmdnZ2d@giganews.com>
Message-ID: <n62dnWKoAucUwxXMnZ2dnUVZ_j6dnZ2d@giganews.com>

On 2013-05-06, Henry Law <news at lawshouse.org> wrote:
> On 05/05/13 18:11, Ignoramus16992 wrote:
>> According to CIO.com
>
> What an amusing thread; lightened my (non-programmer) day.
>

I guess you are from the python newsgroup then. :)


From bradley.wright.biz at gmail.com  Sun May  5 20:59:15 2013
From: bradley.wright.biz at gmail.com (Bradley Wright)
Date: Sun, 5 May 2013 17:59:15 -0700 (PDT)
Subject: (Learner-here) Lists + Functions = headache
Message-ID: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>

Hey guys and gals doing this tutorial(codecademy) and needed a bit help from the experienced.

I'm writing a function that takes a list(one they supply during runtime)
here's what my function is supposed to do

1. for each instance of the string "fizz" make a count
2. Finally return that count

here's my code:

def fizz_cout(x):
    count = 0
    for item in x:
        while item == "fizz":
            count += 1
            return count

Please remember that i am a eager beginner, where am i going wrong?


From wuwei23 at gmail.com  Sun May  5 21:21:33 2013
From: wuwei23 at gmail.com (alex23)
Date: Sun, 5 May 2013 18:21:33 -0700 (PDT)
Subject: (Learner-here) Lists + Functions = headache
References: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
Message-ID: <31f31fc5-65a8-46af-8be8-69c71901278a@tz3g2000pbb.googlegroups.com>

On May 6, 10:59?am, Bradley Wright <bradley.wright.... at gmail.com>
wrote:
> def fizz_cout(x):
> ? ? count = 0
> ? ? for item in x:
> ? ? ? ? while item == "fizz":
> ? ? ? ? ? ? count += 1
> ? ? ? ? ? ? return count
>
> Please remember that i am a eager beginner, where am i going wrong?

There are several problems with your code:

> ? ? for item in x:
> ? ? ? ? while item == "fizz":
> ? ? ? ? ? ? count += 1

The `for` takes an item out of the list `x`. If that item is the
string 'fizz', it increments count. As it's a `while` loop, it will
continue to increment for as long as `item` is 'fizz'. Since the while
loop doesn't look up another list item, it will remain as 'fizz' until
the end of time. Well, it would except for your second bug:

> ? ? ? ? while item == "fizz":
> ? ? ? ? ? ? count += 1
> ? ? ? ? ? ? return count

The very first time it encounters a list item that is 'fizz', it adds
one to `count`, then exits the function passing back `count`.

You want to move the return to _outside_ the for loop, and you want to
change your `while` condition to an `if` instead.




From bradley.wright.biz at gmail.com  Sun May  5 21:24:44 2013
From: bradley.wright.biz at gmail.com (Bradley Wright)
Date: Sun, 5 May 2013 18:24:44 -0700 (PDT)
Subject: (Learner-here) Lists + Functions = headache
In-Reply-To: <31f31fc5-65a8-46af-8be8-69c71901278a@tz3g2000pbb.googlegroups.com>
References: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
	<31f31fc5-65a8-46af-8be8-69c71901278a@tz3g2000pbb.googlegroups.com>
Message-ID: <bc93017c-a6bb-4e7a-bfdc-c75f52ee25d9@googlegroups.com>

On Sunday, May 5, 2013 9:21:33 PM UTC-4, alex23 wrote:
> On May 6, 10:59?am, Bradley Wright <bradley.wright.... at gmail.com>
> 
> wrote:
> 
> > def fizz_cout(x):
> 
> > ? ? count = 0
> 
> > ? ? for item in x:
> 
> > ? ? ? ? while item == "fizz":
> 
> > ? ? ? ? ? ? count += 1
> 
> > ? ? ? ? ? ? return count
> 
> >
> 
> > Please remember that i am a eager beginner, where am i going wrong?
> 
> 
> 
> There are several problems with your code:
> 
> 
> 
> > ? ? for item in x:
> 
> > ? ? ? ? while item == "fizz":
> 
> > ? ? ? ? ? ? count += 1
> 
> 
> 
> The `for` takes an item out of the list `x`. If that item is the
> 
> string 'fizz', it increments count. As it's a `while` loop, it will
> 
> continue to increment for as long as `item` is 'fizz'. Since the while
> 
> loop doesn't look up another list item, it will remain as 'fizz' until
> 
> the end of time. Well, it would except for your second bug:
> 
> 
> 
> > ? ? ? ? while item == "fizz":
> 
> > ? ? ? ? ? ? count += 1
> 
> > ? ? ? ? ? ? return count
> 
> 
> 
> The very first time it encounters a list item that is 'fizz', it adds
> 
> one to `count`, then exits the function passing back `count`.
> 
> 
> 
> You want to move the return to _outside_ the for loop, and you want to
> 
> change your `while` condition to an `if` instead.

Thank you Alex - much appreciated, about to implement right now!


From bradley.wright.biz at gmail.com  Sun May  5 21:30:04 2013
From: bradley.wright.biz at gmail.com (Bradley Wright)
Date: Sun, 5 May 2013 18:30:04 -0700 (PDT)
Subject: (Learner-here) Lists + Functions = headache
In-Reply-To: <bc93017c-a6bb-4e7a-bfdc-c75f52ee25d9@googlegroups.com>
References: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
	<31f31fc5-65a8-46af-8be8-69c71901278a@tz3g2000pbb.googlegroups.com>
	<bc93017c-a6bb-4e7a-bfdc-c75f52ee25d9@googlegroups.com>
Message-ID: <44cd4048-c988-4594-91d9-72ab2b56ad4c@googlegroups.com>

On Sunday, May 5, 2013 9:24:44 PM UTC-4, Bradley Wright wrote:
> On Sunday, May 5, 2013 9:21:33 PM UTC-4, alex23 wrote:
> 
> > On May 6, 10:59?am, Bradley Wright <bradley.wright.... at gmail.com>
> 
> > 
> 
> > wrote:
> 
> > 
> 
> > > def fizz_cout(x):
> 
> > 
> 
> > > ? ? count = 0
> 
> > 
> 
> > > ? ? for item in x:
> 
> > 
> 
> > > ? ? ? ? while item == "fizz":
> 
> > 
> 
> > > ? ? ? ? ? ? count += 1
> 
> > 
> 
> > > ? ? ? ? ? ? return count
> 
> > 
> 
> > >
> 
> > 
> 
> > > Please remember that i am a eager beginner, where am i going wrong?
> 
> > 
> 
> > 
> 
> > 
> 
> > There are several problems with your code:
> 
> > 
> 
> > 
> 
> > 
> 
> > > ? ? for item in x:
> 
> > 
> 
> > > ? ? ? ? while item == "fizz":
> 
> > 
> 
> > > ? ? ? ? ? ? count += 1
> 
> > 
> 
> > 
> 
> > 
> 
> > The `for` takes an item out of the list `x`. If that item is the
> 
> > 
> 
> > string 'fizz', it increments count. As it's a `while` loop, it will
> 
> > 
> 
> > continue to increment for as long as `item` is 'fizz'. Since the while
> 
> > 
> 
> > loop doesn't look up another list item, it will remain as 'fizz' until
> 
> > 
> 
> > the end of time. Well, it would except for your second bug:
> 
> > 
> 
> > 
> 
> > 
> 
> > > ? ? ? ? while item == "fizz":
> 
> > 
> 
> > > ? ? ? ? ? ? count += 1
> 
> > 
> 
> > > ? ? ? ? ? ? return count
> 
> > 
> 
> > 
> 
> > 
> 
> > The very first time it encounters a list item that is 'fizz', it adds
> 
> > 
> 
> > one to `count`, then exits the function passing back `count`.
> 
> > 
> 
> > 
> 
> > 
> 
> > You want to move the return to _outside_ the for loop, and you want to
> 
> > 
> 
> > change your `while` condition to an `if` instead.
> 
> 
> 
> Thank you Alex - much appreciated, about to implement right now!

Aha! lessons learned - got it!


From breamoreboy at yahoo.co.uk  Mon May  6 05:25:59 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 06 May 2013 10:25:59 +0100
Subject: (Learner-here) Lists + Functions = headache
In-Reply-To: <44cd4048-c988-4594-91d9-72ab2b56ad4c@googlegroups.com>
References: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
	<31f31fc5-65a8-46af-8be8-69c71901278a@tz3g2000pbb.googlegroups.com>
	<bc93017c-a6bb-4e7a-bfdc-c75f52ee25d9@googlegroups.com>
	<44cd4048-c988-4594-91d9-72ab2b56ad4c@googlegroups.com>
Message-ID: <km7sv2$cca$1@ger.gmane.org>

On 06/05/2013 02:30, Bradley Wright wrote:
>
> Aha! lessons learned - got it!
>

The next lesson is to read the link given in my signature, digest it and 
take action to avoid masses of superfluous newlines in your responses.

TIA.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From tjreedy at udel.edu  Sun May  5 21:30:25 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 05 May 2013 21:30:25 -0400
Subject: (Learner-here) Lists + Functions = headache
In-Reply-To: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
References: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
Message-ID: <km713c$rck$1@ger.gmane.org>

On 5/5/2013 8:59 PM, Bradley Wright wrote:
> Hey guys and gals doing this tutorial(codecademy) and needed a bit help from the experienced.
>
> I'm writing a function that takes a list(one they supply during runtime)
> here's what my function is supposed to do

Do they supply an example so you can test both your comprehension and 
code? I think most specs given in natural language need such.

> 1. for each instance of the string "fizz" make a count
> 2. Finally return that count

Did you create an example problem to test your code? If not, do so.
Did you run your function with example data? If not, do so.

> here's my code:
>
> def fizz_cout(x):
>      count = 0
>      for item in x:
>          while item == "fizz":
>              count += 1
>              return count

Here is  hint as to some of what needs to be improved: this function 
will return either 1 or None. You should have discovered that by testings.

--
Terry Jan Reedy




From steve+comp.lang.python at pearwood.info  Sun May  5 21:31:48 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 06 May 2013 01:31:48 GMT
Subject: (Learner-here) Lists + Functions = headache
References: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
Message-ID: <51870803$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sun, 05 May 2013 17:59:15 -0700, Bradley Wright wrote:

> Hey guys and gals doing this tutorial(codecademy) and needed a bit help
> from the experienced.
> 
> I'm writing a function that takes a list(one they supply during runtime)
> here's what my function is supposed to do
> 
> 1. for each instance of the string "fizz" make a count 
> 2. Finally return that count
> 
> here's my code:
> 
> def fizz_cout(x):
>     count = 0
>     for item in x:
>         while item == "fizz":
>             count += 1
>             return count
> 
> Please remember that i am a eager beginner, where am i going wrong?

Lots of places, sorry. The first thing you're doing is hoping that we 
will guess what error you are getting. In this case, it so happens that 
we can, but that will not always be the case. You should always give us 
the code (which you have done), the data it is running on, the expected 
result, and the actual result. Within reason: don't bombard us with 
10,000 lines of code and 3MB of data.

Now, moving on to your function: try walking through it yourself in your 
head. You start off by defining a value, then start iterating over each 
value in x, one at a time.


    count = 0
    for item in x:

Suppose x = ["buzz", "fizz", "buzz", "fizz"]. Then you should get a 
result of 2. So far, you start with count = 0. Then you enter the for 
loop, and item gets the value "buzz". The next line enters a while loop:

        while item == "fizz":

Since item does *not* equal "fizz", the body of the while loop does not 
run at all, and Python jumps past the while loop, which takes it to the 
end of the for loop. So Python goes on to the next item. This time item 
gets set to "fizz". So you enter the while loop again, only this time 
item *does* equal "fizz":

        while item == "fizz":
            count += 1
            return count


Oh-oh, trouble ahead. But luckily, you have two bugs, and they *almost* 
cancel themselves out. The first problem is that the while loop would be 
an infinite loop, going around and around and around over and over again, 
since you enter it with item == "fizz" but item always stays equal to 
"fizz". So the first two lines would keep adding one to count, over and 
over again, until count is so big your computer runs out of memory (and 
that might take *months*).

Fortunately, the very next line *almost* overcomes that bug. It doesn't 
*fix* it, but it does reduce the severity. After adding one to count the 
very first time, Python hits the line "return count", which immediately 
exits the function, jumping out of the (infinite) while loop and the for-
loop. So your function always returns either 0 (if there are no "fizz" in 
the list at all) or 1 (if there is any "fizz").

So, you have two problems, and they both need to be fixed:

1) The "return count" line must not happen until the for-loop has 
completed looking at each item in the list. So it must be outside the for-
loop, not inside it. Remember that Python decides what is inside the loop 
by its indentation.

2) You don't want an infinite loop inside the for-loop. There is no need 
to have two loops at all. The outer for-loop is sufficient. You look at 
each item *once*, not over and over again, and decide *once* if you 
should add one to count, then go on to the next item.


-- 
Steven


From steve+comp.lang.python at pearwood.info  Sun May  5 21:48:50 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 06 May 2013 01:48:50 GMT
Subject: (Learner-here) Lists + Functions = headache
References: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
	<51870803$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <51870c02$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Mon, 06 May 2013 01:31:48 +0000, Steven D'Aprano wrote:

> So your function always returns either 0 (if there are no
> "fizz" in the list at all) or 1 (if there is any "fizz").

Correction: (thanks to Terry for pointing this out). It will return None 
or 1, not 0.

How easy it is to fall into the trap of assuming the function will do 
what you intend it to do, instead of what you actually tell it to do :-(



-- 
Steven


From dihedral88888 at googlemail.com  Mon May  6 01:39:21 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Sun, 5 May 2013 22:39:21 -0700 (PDT)
Subject: (Learner-here) Lists + Functions = headache
In-Reply-To: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
References: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
Message-ID: <3a5447e4-4f20-45bb-be22-cf820f2c7737@googlegroups.com>

Bradley Wright? 2013?5?6????UTC+8??8?59?15????
> Hey guys and gals doing this tutorial(codecademy) and needed a bit help from the experienced.
> 
> 
> 
> I'm writing a function that takes a list(one they supply during runtime)
> 
> here's what my function is supposed to do
> 
> 
> 
> 1. for each instance of the string "fizz" make a count
> 
> 2. Finally return that count
> 
> 
> 
> here's my code:
> 
> 
> 
> def fizz_cout(x):
> 
>     count = 0
> 
>     for item in x:
> 
>         while item == "fizz":
> 
>             count += 1
> 

>             return count
> 
This is not indented right in the scope to return 
the total count.



From rosuav at gmail.com  Mon May  6 03:32:23 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 6 May 2013 17:32:23 +1000
Subject: (Learner-here) Lists + Functions = headache
In-Reply-To: <3a5447e4-4f20-45bb-be22-cf820f2c7737@googlegroups.com>
References: <ed7e2a6d-ad84-49b1-afae-6d1516fc1130@googlegroups.com>
	<3a5447e4-4f20-45bb-be22-cf820f2c7737@googlegroups.com>
Message-ID: <CAPTjJmqLEyzy1xewpLf8NqYd7R6Khqmy1f+vz7aq6Guik-wNqw@mail.gmail.com>

On Mon, May 6, 2013 at 3:39 PM, 88888 Dihedral
<dihedral88888 at googlemail.com> wrote:
> Bradley Wright? 2013?5?6????UTC+8??8?59?15????
>> def fizz_cout(x):
>>
>>     count = 0
>>
>>     for item in x:
>>
>>         while item == "fizz":
>>
>>             count += 1
>>
>
>>             return count
>>
> This is not indented right in the scope to return
> the total count.

Wow. You know a question's been asked frequently when even the bots
can learn to answer it correctly.

ChrisA


From info at egenix.com  Mon May  6 04:00:52 2013
From: info at egenix.com (eGenix Team: M.-A. Lemburg)
Date: Mon, 06 May 2013 10:00:52 +0200
Subject: ANN: eGenix mxODBC 3.2.3 - Python ODBC Database Interface
Message-ID: <51876334.1060807@egenix.com>

________________________________________________________________________

ANNOUNCING

                         eGenix.com mxODBC

                   Python ODBC Database Interface

                           Version 3.2.3


    mxODBC is our commercially supported Python extension providing
         ODBC database connectivity to Python applications
            on Windows, Mac OS X, Unix and BSD platforms


This announcement is also available on our web-site for online reading:
http://www.egenix.com/company/news/eGenix-mxODBC-3.2.3-GA.html

________________________________________________________________________

INTRODUCTION

mxODBC provides an easy-to-use, high-performance, reliable and robust
Python interface to ODBC compatible databases such as MS SQL Server,
MS Access, Oracle Database, IBM DB2 and Informix , Sybase ASE and
Sybase Anywhere, MySQL, PostgreSQL, SAP MaxDB and many more:

    http://www.egenix.com/products/python/mxODBC/

The "eGenix mxODBC - Python ODBC Database Interface" product is a
commercial extension to our open-source eGenix mx Base Distribution:

    http://www.egenix.com/products/python/mxBase/

________________________________________________________________________

NEWS

The 3.2.3 release of our mxODBC is the latest patch level release of
our popular Python ODBC Interface. In this release, we've included the
following the following enhancements and fixes:

Compatibility Enhancements
--------------------------

 * Added a work-around for a regression in Python 2.7.4 that results
   in a segfault when exiting Python after loading mxODBC.

   The regression will be fixed in Python 2.7.5, but we don't want to
   expose our users to segfaults, so added a work-around.

   See http://bugs.python.org/issue17703 for the bug ticket.

 * Please also see the mxODBC 3.2.2 announcement for an important new
   feature which allows to dramatically increase the fetch performance
   when working with MS SQL Server and IBM DB2 databases:

   http://www.egenix.com/company/news/eGenix-mxODBC-3.2.2-GA.html

Fixes
-----

 * Fixed a bugglet which caused connection.__members__ to no longer
   list connection attributes.

For the full set of changes please check the mxODBC change log:

    http://www.egenix.com/products/python/mxODBC/changelog.html

________________________________________________________________________

FEATURES

mxODBC 3.2 was released on 2012-08-28. Please see the full
announcement for highlights of the 3.2 release:

    http://www.egenix.com/company/news/eGenix-mxODBC-3.2.0-GA.html

For the full set of features mxODBC has to offer, please see:

    http://www.egenix.com/products/python/mxODBC/#Features

________________________________________________________________________

EDITIONS

mxODBC is available in these three editions:

 * The low-cost Standard Edition which provides data connectivity to a
   single database type, e.g. just MS SQL Server.

 * The Professional Edition, which gives full access to all mxODBC
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From amirouche.boubekki at gmail.com  Mon May  6 06:16:37 2013
From: amirouche.boubekki at gmail.com (Amirouche Boubekki)
Date: Mon, 6 May 2013 12:16:37 +0200
Subject: pyC11 initial publication
In-Reply-To: <km2bmfUdb2L1@news.in-ulm.de>
References: <km2bmfUdb2L1@news.in-ulm.de>
Message-ID: <CAL7_Mo9Kpp6HHzbXZ2Kz5pgSj=DnNcd3gp6-S4=6XoGgcJWRDg@mail.gmail.com>

H?llo,

Does it support macros ? Is it possible to retrieve the list of macros and
define macro values ?

Thanks,

Amirouche


2013/5/4 Volker Birk <bumens at dingens.org>

> pyC11 is a grammar to parse programs in the C programming language
> following ISO/IEC 9899:2011. It is written using pyPEG, a parsing
> framework for Python. The grammar supports Python 2.7 and 3.x. The test
> bench requires py.test.
>
> This is the initial upload. The grammar is incomplete. Parsing C
> expressions works, but parsing complete C programs does not work yet.
>
> pyC11 is meant to be used for parsing, modifying and generating C
> expressions and programs. It is a real world sample how to use pyPEG.
> pyC11 is provided under the GNU GPL 2.0.
>
> You can find pyC11 on Bitbucket at <https://bitbucket.org/fdik/pyc11>.
>
> Yours,
> VB.
> --
> Volker Birk, Oberer Graben 4, CH-8400 Winterthur, Schweiz,
> Erde, Solar-System, Orion Arm, Milchstrasse, Lokale Gruppe,
> Virgo-Superhaufen, Coma-Virgo-Filament. mailto:dingens at bumens.org
> http://fdik.org  D-IRCNet fdik!vb at dragon.pibit.ch
> --
> http://mail.python.org/mailman/listinfo/python-announce-list
>
>         Support the Python Software Foundation:
>         http://www.python.org/psf/donations/
>
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From eric.frederich at gmail.com  Mon May  6 14:11:46 2013
From: eric.frederich at gmail.com (Eric Frederich)
Date: Mon, 6 May 2013 14:11:46 -0400
Subject: distributing a binary package
Message-ID: <CAAoZyYNjsjeP3h1xu98t27+zH07QzUGCaoUiZSCZchR-FOAEzg@mail.gmail.com>

Hello,

Hopefully a simple question.
Basically, I'd like to know how to create a proper setup.py script to
install a package.
The package exists as a single directory with a single __init__.py
file and (currently) 93 .so files.

Right now I just copy it into the site-packages directory but I'd like
to start using virtualenv / pip so I'd like to do the installation via
"python setup.py install".

I need to keep my build process external to this for performance
reasons (with a Makefile I can do parallel builds and I have a machine
with 12 cores).

My Makefile does all the work.  It produces a directory that simply
needs to be copied to site-packages.... but how do I craft a setup.py
script to do the actually installation?

Thanks,
~Eric


From miki.tebeka at gmail.com  Mon May  6 21:13:15 2013
From: miki.tebeka at gmail.com (Miki Tebeka)
Date: Mon, 6 May 2013 18:13:15 -0700 (PDT)
Subject: distributing a binary package
In-Reply-To: <mailman.1368.1367863915.3114.python-list@python.org>
References: <mailman.1368.1367863915.3114.python-list@python.org>
Message-ID: <fdc71561-c13d-4632-a720-b4d95c15918e@googlegroups.com>

 
> Basically, I'd like to know how to create a proper setup.py script
http://docs.python.org/2/distutils/setupscript.html


From eric.frederich at gmail.com  Tue May  7 09:48:32 2013
From: eric.frederich at gmail.com (Eric Frederich)
Date: Tue, 7 May 2013 09:48:32 -0400
Subject: distributing a binary package
In-Reply-To: <fdc71561-c13d-4632-a720-b4d95c15918e@googlegroups.com>
References: <mailman.1368.1367863915.3114.python-list@python.org>
	<fdc71561-c13d-4632-a720-b4d95c15918e@googlegroups.com>
Message-ID: <CAAoZyYMyPmz5t5QNJCtR9ZwAiDzj3SnFq2PFfe-KixHfV2OCZg@mail.gmail.com>

I see where I can specify a module that distutils will try to compile.
I already have the .so files compiled.

I'm sure its simple, I just can't find it or don't know what to look for.

On Mon, May 6, 2013 at 9:13 PM, Miki Tebeka <miki.tebeka at gmail.com> wrote:
>
>> Basically, I'd like to know how to create a proper setup.py script
> http://docs.python.org/2/distutils/setupscript.html
> --
> http://mail.python.org/mailman/listinfo/python-list


From miki.tebeka at gmail.com  Tue May  7 20:58:44 2013
From: miki.tebeka at gmail.com (Miki Tebeka)
Date: Tue, 7 May 2013 17:58:44 -0700 (PDT)
Subject: distributing a binary package
In-Reply-To: <mailman.1411.1367934880.3114.python-list@python.org>
References: <mailman.1368.1367863915.3114.python-list@python.org>
	<fdc71561-c13d-4632-a720-b4d95c15918e@googlegroups.com>
	<mailman.1411.1367934880.3114.python-list@python.org>
Message-ID: <b0fb8305-f063-4c7e-b2c1-7abd9fb6edb2@googlegroups.com>

> I already have the .so files compiled.
http://docs.python.org/2/distutils/setupscript.html#installing-package-data ?


From lm.raaijmakers at gmail.com  Mon May  6 14:39:23 2013
From: lm.raaijmakers at gmail.com (Linsey Raaijmakers)
Date: Mon, 6 May 2013 11:39:23 -0700 (PDT)
Subject: find overlapping lines & output times observed
Message-ID: <05aadf46-6cf2-4040-84e6-4e480528f6fd@googlegroups.com>

Hello,

I have a file like this:
action start    end
50	5321 	5321
7	5323	        5347
12	5339	        5351
45	5373  	5373
45	5420	        5420
25	5425	        5425
26	5425	        5425
50	5451	        5451
45	5452  	5452
14	5497	        5503
26	5513	        5513
25	5517	        5517
45	5533	        5533
50	5533	        5533
5	5537	        5540
25	5580	        5580
45	5586  	5586
26	5595	        5595
45	5603	        5603
50	5634	        5634
45	5645	        5645
7	5657	        5689
25	5682	        5682
26	5682	        5690
26	5708	        5708
45	5717     	5717
50	5740	        5740
45	5777	        5777
45	5804	        5804
7	5805	        5845

and want to find how many times combinations occur in a time frame (between column 2 and 3 ). This can be multiple combinations, which is my problem now.
I have no problems finding overlap between 2 actions. 
I want to start with the first line, action 50. and check for all lines in the rest of the file if there are lines that overlap this action.
So the first line has no overlap, but action 25 and 26 would be a combination that overlaps, and 45 and 50 (5533	-5533). but 7,25,26 would be a combination of 3(5682-5682 & 5682-5690 & 5657-5689 because these three overlap each other.

I have a script now that identifies overlap between two actions (see bottom page), but how can I change this so that it outputs all possible combinations?

My desired output would be:

action    times observed    apex
50         5                          5321, 5451, 5533, 5634,  5740
50,45    1                          5533;5533
7           4                          5347, 5689, 5688, 5845
7,25      2                          5347;5425, 5689;5682
7,25,26 1                          5689;5682;5690

CODE: 

from collections import Counter
f = open('and.txt','r');

action_list = []
onset_list = []
apex_list = []
offset_list = []
action_counter = 0
combination_list = []


for line in f:
  fields = line.split("\t")
  for col in fields:
    action = fields[0]
    onset = fields[1]
    apex = fields[2]
    offset = fields[3]

  action_list.append(action)
  onset_list.append(onset)
  apex_list.append(apex)
  offset_list.append(offset)

action_cnvrt = map(int, action_list)
c = Counter(action_cnvrt)

filtered = list(set(action_list))
filtered_cnvrt = map(int, filtered)

for a in filtered_cnvrt:
  action_count = str(a)+"\t"+str(c[a])
  print action_count

for i in range (0,len(onset_list)):
  combination_list.append(action_list[i])
  for j in range(0,len(apex_list)):
    if i != j:
      if onset_list[j]>= onset_list[i] and apex_list[j] <= apex_list[i]:
        print action_list[j]+","+action_list[i]+'\t'+onset_list[j]+'\t'+apex_list[j]+'\t'+onset_list[i]+'\t'+apex_list[i]


I hope somebody can help me :)


From oscar.j.benjamin at gmail.com  Mon May  6 16:32:33 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Mon, 6 May 2013 21:32:33 +0100
Subject: find overlapping lines & output times observed
In-Reply-To: <05aadf46-6cf2-4040-84e6-4e480528f6fd@googlegroups.com>
References: <05aadf46-6cf2-4040-84e6-4e480528f6fd@googlegroups.com>
Message-ID: <CAHVvXxRsxaocmK2zczJdQYHw+eCujuMF-caPLNqTNP2i852jFA@mail.gmail.com>

On 6 May 2013 19:39, Linsey Raaijmakers <lm.raaijmakers at gmail.com> wrote:
> I have a file like this:
> action start    end
> 50      5321    5321
> 7       5323            5347
> 12      5339            5351
> 45      5373    5373
> 45      5420            5420
> 25      5425            5425
[snip]

your code below suggests that your file also has an "apex" column. If
that's correct what do you what is it and what do you want to do with
it?

[snip]
> I have a script now that identifies overlap between two actions (see bottom page), but how can I change this so that it outputs all possible combinations?

I looked at that code and I don't think it does what you describe. Are
you sure that it works?

> My desired output would be:
>
> action    times observed    apex
> 50         5                          5321, 5451, 5533, 5634,  5740
> 50,45    1                          5533;5533
> 7           4                          5347, 5689, 5688, 5845
> 7,25      2                          5347;5425, 5689;5682
> 7,25,26 1                          5689;5682;5690
>
> CODE:
>
> from collections import Counter
> f = open('and.txt','r');
>
> action_list = []
> onset_list = []
> apex_list = []
> offset_list = []
> action_counter = 0
> combination_list = []
>
>
> for line in f:
>   fields = line.split("\t")
>   for col in fields:
>     action = fields[0]
>     onset = fields[1]
>     apex = fields[2]
>     offset = fields[3]

The above code suggests that the file has four columns. Also since
you're not actually using the loop variable "col" you can just delete
the "for" line and unindent the rest. In fact the easiest way to do
all of this is just:

    action, onset, apex, offset = line.split()

>
>   action_list.append(action)
>   onset_list.append(onset)
>   apex_list.append(apex)
>   offset_list.append(offset)
>
> action_cnvrt = map(int, action_list)
> c = Counter(action_cnvrt)
>
> filtered = list(set(action_list))

There's no need to convert this back to a list if you're just going to
iterate over it again with map.

> filtered_cnvrt = map(int, filtered)
>
> for a in filtered_cnvrt:
>   action_count = str(a)+"\t"+str(c[a])
>   print action_count

The above counts the number of times each event occurs which is one
part of your desired output.

>
> for i in range (0,len(onset_list)):
>   combination_list.append(action_list[i])
>   for j in range(0,len(apex_list)):
>     if i != j:
>       if onset_list[j]>= onset_list[i] and apex_list[j] <= apex_list[i]:
>         print action_list[j]+","+action_list[i]+'\t'+onset_list[j]+'\t'+apex_list[j]+'\t'+onset_list[i]+'\t'+apex_list[i]

What is combination_list for? It should just end up containing the
same thing as action_list if I understand correctly.

It's generally better in Python to loop directly over things rather
than using indices so, instead of something like:

  for i in range(len(onset_list)):
    print offset_list[i] - onset_list[i]

you should do something like

  for offset, onset in zip(offset_list, onset_list):
    print offset - onset

and your code will be a lot clearer.

The algorithm you are using is to loop over all events and then to
loop over all other events comparing all pairs of events. This will
not scale very well if you want to look at a large file or to compare
simultaneous occurrences of more than two events.

It looks as if your input data is ordered by the onset column. Is that
the case? If so then you can use an algorithm that just loops once
over all the events. The way the algorithm works is that you store
which events are currently active and loop through the events keeping
track of the start time of the most recently added event adding and
removing events as they start and stop. In pseudocode:

now = start of first event
active = [first event]
for next_starting in events (not including first):
    next_ending = event that ends soonest from active
    while start of next_starting > end of next_ending:
        report active events from now to end of next_ending
        now = end of next_ending
        remove next_ending from active
    report active events from now until start of next_starting
    now = start of next_starting
    add next_starting to active

And some more code to deal with what happens when you get to the end
of the list of events...

The report steps probably mean adding to a Counter or dict to remember
that the currently active events were active during each particular
time window.


Oscar


From miltmobley at gmail.com  Mon May  6 14:50:47 2013
From: miltmobley at gmail.com (Milton Mobley)
Date: Mon, 6 May 2013 11:50:47 -0700
Subject: module install failures
Message-ID: <CAB5G33drp=1W1DmCkUA_qyhHF-y+9gCRvYMCwr2AqLG3bco7PQ@mail.gmail.com>

Hi there, I hate to bother you with this, but there doesn't seem to be any
ordinary online help for such issues at python.org:

Lately I have tried to install several Python modules that are wrappers for
C/C++ base libraries on a Windows 7 64 bit system.
I used pip in a virtualenv environment, and some script fails complaining
that it can't find vcvarsall.bat. I found the file in my
Visual Studio 10 Express tree, but the script can't find it. How can I fix
the script to look in the right place?
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From breamoreboy at yahoo.co.uk  Mon May  6 15:49:19 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 06 May 2013 20:49:19 +0100
Subject: module install failures
In-Reply-To: <CAB5G33drp=1W1DmCkUA_qyhHF-y+9gCRvYMCwr2AqLG3bco7PQ@mail.gmail.com>
References: <CAB5G33drp=1W1DmCkUA_qyhHF-y+9gCRvYMCwr2AqLG3bco7PQ@mail.gmail.com>
Message-ID: <km91fs$qo0$1@ger.gmane.org>

On 06/05/2013 19:50, Milton Mobley wrote:
> Hi there, I hate to bother you with this, but there doesn't seem to be
> any ordinary online help for such issues at python.org <http://python.org>:
>
> Lately I have tried to install several Python modules that are wrappers
> for C/C++ base libraries on a Windows 7 64 bit system.
> I used pip in a virtualenv environment, and some script fails
> complaining that it can't find vcvarsall.bat. I found the file in my
> Visual Studio 10 Express tree, but the script can't find it. How can I
> fix the script to look in the right place?
>
>

Hopefully this helps 
http://old.nabble.com/Re%3A-Unable-to-install-PyWin32-with-Python-2.6.2-p25202902.html

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From programmer.toronto at gmail.com  Mon May  6 15:01:06 2013
From: programmer.toronto at gmail.com (MMZ)
Date: Mon, 6 May 2013 12:01:06 -0700 (PDT)
Subject: python backup script
Message-ID: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>

I am trying to backup database on CentOS linux server,I'm getting error when running the following script. anyone can help?


#!/usr/bin/env python
import ConfigParser
import os
import time

config = ConfigParser.ConfigParser()
config.read("~/my.cnf")
username = config.get('client', 'mmz')
password = config.get('client', 'pass1')
hostname = config.get('client', 'localhost')
filestamp = time.strftime('%Y-%m-%d')

# Get a list of databases with :
Database_list_command="mysql -u %s -p%s -h %s --silent -N -e 'show databases'" % (username, password, hostname)
for database in os.popen(database_list_command).readlines():
    database = database.strip()
    if database == 'information_schema':
        continue
    if database == 'db_dev':
        continue
    filename = "/backups/mysql/%s-%s.sql" % (database, filestamp)
    os.popen("mysqldump -u %s -p%s -h %s -e --opt -c %s | gzip -c > %s.gz" % (username, password, hostname, database, filename))



............Error..........

Traceback (most recent call last):
  File "./backup.py", line 8, in ?
    username = config.get('client', 'mmz')
  File "/usr/lib/python2.4/ConfigParser.py", line 511, in get
    raise NoSectionError(section)





From malaclypse2 at gmail.com  Mon May  6 15:11:33 2013
From: malaclypse2 at gmail.com (Jerry Hill)
Date: Mon, 6 May 2013 15:11:33 -0400
Subject: python backup script
In-Reply-To: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
Message-ID: <CADwdpybwb4e60PZh-fw24i-UJStVotj=upV2Sy8q1x0kCvMjng@mail.gmail.com>

On Mon, May 6, 2013 at 3:01 PM, MMZ <programmer.toronto at gmail.com> wrote:

> I am trying to backup database on CentOS linux server,I'm getting error
> when running the following script. anyone can help?
>
> Traceback (most recent call last):
>   File "./backup.py", line 8, in ?
>     username = config.get('client', 'mmz')
>   File "/usr/lib/python2.4/ConfigParser.py", line 511, in get
>     raise NoSectionError(section)
>

?I've never used ConfigParser, but that ?

?error message looks pretty simple to interpret.  You've set up a
ConfigParser object, told it to read in ~/my.cnf, the asked for the value
of section 'client', option 'mmz'.  The error indicates that your config
files doesn't have a section named 'client'.

What is the content of your ~/my.cnf file?

-- 
Jerry
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From programmer.toronto at gmail.com  Mon May  6 15:20:51 2013
From: programmer.toronto at gmail.com (MMZ)
Date: Mon, 6 May 2013 12:20:51 -0700 (PDT)
Subject: python backup script
In-Reply-To: <mailman.1371.1367867496.3114.python-list@python.org>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<mailman.1371.1367867496.3114.python-list@python.org>
Message-ID: <51f5c8c4-b40b-4a1e-b72b-905caa62aaf6@googlegroups.com>

On Monday, May 6, 2013 3:11:33 PM UTC-4, Jerry Hill wrote:
> On Mon, May 6, 2013 at 3:01 PM, MMZ <programme... at gmail.com> wrote:
> 
> 
> 
> I am trying to backup database on CentOS linux server,I'm getting error when running the following script. anyone can help?
> 
> 
> 
> 
> Traceback (most recent call last):
> 
> ? File "./backup.py", line 8, in ?
> 
> ? ? username = config.get('client', 'mmz')
> 
> ? File "/usr/lib/python2.4/ConfigParser.py", line 511, in get
> 
> ? ? raise NoSectionError(section)
> 
> 
> 
> I've never used ConfigParser, but that ?
> 
> error message looks pretty simple to interpret.? You've set up a ConfigParser object, told it to read in ~/my.cnf, the asked for the value of section 'client', option 'mmz'.? The error indicates that your config files doesn't have a section named 'client'.
> 
> 
> 
> What is the content of your ~/my.cnf file?
> 
> -- 
> 
> 
> Jerry

Thank you for helping Jerry. Actually I found this script for debian but I want to use it for CentOS server so I replaced /etc/mysql/debian.cnf with ~/my.cnf
the file content is:

 Example MySQL config file for medium systems.
#
# This is for a system with little memory (32M - 64M) where MySQL plays
# an important part, or systems up to 128M where MySQL is used together with
# other programs (such as a web server)
#
# MySQL programs look for option files in a set of
# locations which depend on the deployment platform.
# You can copy this option file to one of those
# locations. For information about these locations, see:
# http://dev.mysql.com/doc/mysql/en/option-files.html
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.

# The following options will be passed to all MySQL clients
[client]
#password       = your_password
port            = 3306
socket          = /tmp/mysql.sock

# Here follows entries for some specific programs

# The MySQL server
[mysqld]
port            = 3306
socket          = /tmp/mysql.sock
skip-locking
key_buffer_size = 16M
max_allowed_packet = 1M
table_open_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M

# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
#
#skip-networking

# Replication Master Server (default)
# binary logging is required for replication
log-bin=mysql-bin

# binary logging format - mixed recommended
binlog_format=mixed

# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id       = 1


From matt.walker.jones at gmail.com  Mon May  6 15:46:04 2013
From: matt.walker.jones at gmail.com (Matt Jones)
Date: Mon, 6 May 2013 14:46:04 -0500
Subject: python backup script
In-Reply-To: <51f5c8c4-b40b-4a1e-b72b-905caa62aaf6@googlegroups.com>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<mailman.1371.1367867496.3114.python-list@python.org>
	<51f5c8c4-b40b-4a1e-b72b-905caa62aaf6@googlegroups.com>
Message-ID: <CANuMAv97YykEM6Q96H3Uf-mmst91t8dw7pbmJTDYs4b0nKKtHA@mail.gmail.com>

I've never used ConfigParser either, but shouldn't the "[client]" section
have the options "mmz", "pass1", or "localhost" somewhere?  Do you need to
add them to that file?

*Matt Jones*


On Mon, May 6, 2013 at 2:20 PM, MMZ <programmer.toronto at gmail.com> wrote:

> On Monday, May 6, 2013 3:11:33 PM UTC-4, Jerry Hill wrote:
> > On Mon, May 6, 2013 at 3:01 PM, MMZ <programme... at gmail.com> wrote:
> >
> >
> >
> > I am trying to backup database on CentOS linux server,I'm getting error
> when running the following script. anyone can help?
> >
> >
> >
> >
> > Traceback (most recent call last):
> >
> >   File "./backup.py", line 8, in ?
> >
> >     username = config.get('client', 'mmz')
> >
> >   File "/usr/lib/python2.4/ConfigParser.py", line 511, in get
> >
> >     raise NoSectionError(section)
> >
> >
> >
> > I've never used ConfigParser, but that
> >
> > error message looks pretty simple to interpret.  You've set up a
> ConfigParser object, told it to read in ~/my.cnf, the asked for the value
> of section 'client', option 'mmz'.  The error indicates that your config
> files doesn't have a section named 'client'.
> >
> >
> >
> > What is the content of your ~/my.cnf file?
> >
> > --
> >
> >
> > Jerry
>
> Thank you for helping Jerry. Actually I found this script for debian but I
> want to use it for CentOS server so I replaced /etc/mysql/debian.cnf with
> ~/my.cnf
> the file content is:
>
>  Example MySQL config file for medium systems.
> #
> # This is for a system with little memory (32M - 64M) where MySQL plays
> # an important part, or systems up to 128M where MySQL is used together
> with
> # other programs (such as a web server)
> #
> # MySQL programs look for option files in a set of
> # locations which depend on the deployment platform.
> # You can copy this option file to one of those
> # locations. For information about these locations, see:
> # http://dev.mysql.com/doc/mysql/en/option-files.html
> #
> # In this file, you can use all long options that a program supports.
> # If you want to know which options a program supports, run the program
> # with the "--help" option.
>
> # The following options will be passed to all MySQL clients
> [client]
> #password       = your_password
> port            = 3306
> socket          = /tmp/mysql.sock
>
> # Here follows entries for some specific programs
>
> # The MySQL server
> [mysqld]
> port            = 3306
> socket          = /tmp/mysql.sock
> skip-locking
> key_buffer_size = 16M
> max_allowed_packet = 1M
> table_open_cache = 64
> sort_buffer_size = 512K
> net_buffer_length = 8K
> read_buffer_size = 256K
> read_rnd_buffer_size = 512K
> myisam_sort_buffer_size = 8M
>
> # Don't listen on a TCP/IP port at all. This can be a security enhancement,
> # if all processes that need to connect to mysqld run on the same host.
> # All interaction with mysqld must be made via Unix sockets or named pipes.
> # Note that using this option without enabling named pipes on Windows
> # (via the "enable-named-pipe" option) will render mysqld useless!
> #
> #skip-networking
>
> # Replication Master Server (default)
> # binary logging is required for replication
> log-bin=mysql-bin
>
> # binary logging format - mixed recommended
> binlog_format=mixed
>
> # required unique id between 1 and 2^32 - 1
> # defaults to 1 if master-host is not set
> # but will not function as a master if omitted
> server-id       = 1
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From programmer.toronto at gmail.com  Mon May  6 16:37:34 2013
From: programmer.toronto at gmail.com (MMZ)
Date: Mon, 6 May 2013 13:37:34 -0700 (PDT)
Subject: python backup script
In-Reply-To: <mailman.1373.1367870074.3114.python-list@python.org>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<mailman.1371.1367867496.3114.python-list@python.org>
	<51f5c8c4-b40b-4a1e-b72b-905caa62aaf6@googlegroups.com>
	<mailman.1373.1367870074.3114.python-list@python.org>
Message-ID: <489bad9e-4a96-4d51-98ea-ce59c2573e4f@googlegroups.com>

Thanks Matt. 
my.cnf is a readonly file and cannot be changed or modified but do you know of a file that stores similar information on CentOS?I think I'm not reading from a right file maybe.

On Monday, May 6, 2013 3:46:04 PM UTC-4, Matt Jones wrote:
> I've never used ConfigParser either, but shouldn't the "[client]" section have the options "mmz", "pass1", or "localhost" somewhere? ?Do you need to add them to that file?
> 
> 
> 
> 
> Matt Jones
> 
> 
> 
> On Mon, May 6, 2013 at 2:20 PM, MMZ <programme... at gmail.com> wrote:
> 
> 
> On Monday, May 6, 2013 3:11:33 PM UTC-4, Jerry Hill wrote:
> 
> 
> > On Mon, May 6, 2013 at 3:01 PM, MMZ <programme... at gmail.com> wrote:
> 
> >
> 
> >
> 
> >
> 
> > I am trying to backup database on CentOS linux server,I'm getting error when running the following script. anyone can help?
> 
> >
> 
> >
> 
> >
> 
> >
> 
> 
> > Traceback (most recent call last):
> 
> >
> 
> > ? File "./backup.py", line 8, in ?
> 
> >
> 
> > ? ? username = config.get('client', 'mmz')
> 
> >
> 
> > ? File "/usr/lib/python2.4/ConfigParser.py", line 511, in get
> 
> >
> 
> > ? ? raise NoSectionError(section)
> 
> >
> 
> >
> 
> >
> 
> 
> > I've never used ConfigParser, but that ?
> 
> >
> 
> > error message looks pretty simple to interpret.? You've set up a ConfigParser object, told it to read in ~/my.cnf, the asked for the value of section 'client', option 'mmz'.? The error indicates that your config files doesn't have a section named 'client'.
> 
> 
> 
> >
> 
> >
> 
> >
> 
> > What is the content of your ~/my.cnf file?
> 
> >
> 
> > --
> 
> >
> 
> >
> 
> > Jerry
> 
> 
> 
> Thank you for helping Jerry. Actually I found this script for debian but I want to use it for CentOS server so I replaced /etc/mysql/debian.cnf with ~/my.cnf
> 
> the file content is:
> 
> 
> 
> ?Example MySQL config file for medium systems.
> 
> #
> 
> # This is for a system with little memory (32M - 64M) where MySQL plays
> 
> # an important part, or systems up to 128M where MySQL is used together with
> 
> # other programs (such as a web server)
> 
> #
> 
> # MySQL programs look for option files in a set of
> 
> # locations which depend on the deployment platform.
> 
> # You can copy this option file to one of those
> 
> # locations. For information about these locations, see:
> 
> # http://dev.mysql.com/doc/mysql/en/option-files.html
> 
> #
> 
> # In this file, you can use all long options that a program supports.
> 
> # If you want to know which options a program supports, run the program
> 
> # with the "--help" option.
> 
> 
> 
> # The following options will be passed to all MySQL clients
> 
> [client]
> 
> #password ? ? ? = your_password
> 
> port ? ? ? ? ? ?= 3306
> 
> socket ? ? ? ? ?= /tmp/mysql.sock
> 
> 
> 
> # Here follows entries for some specific programs
> 
> 
> 
> # The MySQL server
> 
> [mysqld]
> 
> port ? ? ? ? ? ?= 3306
> 
> socket ? ? ? ? ?= /tmp/mysql.sock
> 
> skip-locking
> 
> key_buffer_size = 16M
> 
> max_allowed_packet = 1M
> 
> table_open_cache = 64
> 
> sort_buffer_size = 512K
> 
> net_buffer_length = 8K
> 
> read_buffer_size = 256K
> 
> read_rnd_buffer_size = 512K
> 
> myisam_sort_buffer_size = 8M
> 
> 
> 
> # Don't listen on a TCP/IP port at all. This can be a security enhancement,
> 
> # if all processes that need to connect to mysqld run on the same host.
> 
> # All interaction with mysqld must be made via Unix sockets or named pipes.
> 
> # Note that using this option without enabling named pipes on Windows
> 
> # (via the "enable-named-pipe" option) will render mysqld useless!
> 
> #
> 
> #skip-networking
> 
> 
> 
> # Replication Master Server (default)
> 
> # binary logging is required for replication
> 
> log-bin=mysql-bin
> 
> 
> 
> # binary logging format - mixed recommended
> 
> binlog_format=mixed
> 
> 
> 
> # required unique id between 1 and 2^32 - 1
> 
> # defaults to 1 if master-host is not set
> 
> # but will not function as a master if omitted
> 
> server-id ? ? ? = 1
> 
> --
> 
> http://mail.python.org/mailman/listinfo/python-list



From matt.walker.jones at gmail.com  Mon May  6 17:08:20 2013
From: matt.walker.jones at gmail.com (Matt Jones)
Date: Mon, 6 May 2013 16:08:20 -0500
Subject: python backup script
In-Reply-To: <489bad9e-4a96-4d51-98ea-ce59c2573e4f@googlegroups.com>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<mailman.1371.1367867496.3114.python-list@python.org>
	<51f5c8c4-b40b-4a1e-b72b-905caa62aaf6@googlegroups.com>
	<mailman.1373.1367870074.3114.python-list@python.org>
	<489bad9e-4a96-4d51-98ea-ce59c2573e4f@googlegroups.com>
Message-ID: <CANuMAv-_fW0fH9jzgnKyNisHWxM8C7Qzg2pbafQGoCj==Y8kew@mail.gmail.com>

Why do you have to use that file?  Why can't you copy its contents into a
new file in your working directory and make whatever changes necessary?


Example of the changes your code makes me think you want:

************************
# The following options will be passed to all MySQL clients
[client]
#password       = your_password
port            = 3306
socket          = /tmp/mysql.sock
mmz          = bleh
pass1          = blah
localhost          = bluargh


*Matt Jones*


On Mon, May 6, 2013 at 3:37 PM, MMZ <programmer.toronto at gmail.com> wrote:

> Thanks Matt.
> my.cnf is a readonly file and cannot be changed or modified but do you
> know of a file that stores similar information on CentOS?I think I'm not
> reading from a right file maybe.
>
> On Monday, May 6, 2013 3:46:04 PM UTC-4, Matt Jones wrote:
> > I've never used ConfigParser either, but shouldn't the "[client]"
> section have the options "mmz", "pass1", or "localhost" somewhere?  Do you
> need to add them to that file?
> >
> >
> >
> >
> > Matt Jones
> >
> >
> >
> > On Mon, May 6, 2013 at 2:20 PM, MMZ <programme... at gmail.com> wrote:
> >
> >
> > On Monday, May 6, 2013 3:11:33 PM UTC-4, Jerry Hill wrote:
> >
> >
> > > On Mon, May 6, 2013 at 3:01 PM, MMZ <programme... at gmail.com> wrote:
> >
> > >
> >
> > >
> >
> > >
> >
> > > I am trying to backup database on CentOS linux server,I'm getting
> error when running the following script. anyone can help?
> >
> > >
> >
> > >
> >
> > >
> >
> > >
> >
> >
> > > Traceback (most recent call last):
> >
> > >
> >
> > >   File "./backup.py", line 8, in ?
> >
> > >
> >
> > >     username = config.get('client', 'mmz')
> >
> > >
> >
> > >   File "/usr/lib/python2.4/ConfigParser.py", line 511, in get
> >
> > >
> >
> > >     raise NoSectionError(section)
> >
> > >
> >
> > >
> >
> > >
> >
> >
> > > I've never used ConfigParser, but that
> >
> > >
> >
> > > error message looks pretty simple to interpret.  You've set up a
> ConfigParser object, told it to read in ~/my.cnf, the asked for the value
> of section 'client', option 'mmz'.  The error indicates that your config
> files doesn't have a section named 'client'.
> >
> >
> >
> > >
> >
> > >
> >
> > >
> >
> > > What is the content of your ~/my.cnf file?
> >
> > >
> >
> > > --
> >
> > >
> >
> > >
> >
> > > Jerry
> >
> >
> >
> > Thank you for helping Jerry. Actually I found this script for debian but
> I want to use it for CentOS server so I replaced /etc/mysql/debian.cnf with
> ~/my.cnf
> >
> > the file content is:
> >
> >
> >
> >  Example MySQL config file for medium systems.
> >
> > #
> >
> > # This is for a system with little memory (32M - 64M) where MySQL plays
> >
> > # an important part, or systems up to 128M where MySQL is used together
> with
> >
> > # other programs (such as a web server)
> >
> > #
> >
> > # MySQL programs look for option files in a set of
> >
> > # locations which depend on the deployment platform.
> >
> > # You can copy this option file to one of those
> >
> > # locations. For information about these locations, see:
> >
> > # http://dev.mysql.com/doc/mysql/en/option-files.html
> >
> > #
> >
> > # In this file, you can use all long options that a program supports.
> >
> > # If you want to know which options a program supports, run the program
> >
> > # with the "--help" option.
> >
> >
> >
> > # The following options will be passed to all MySQL clients
> >
> > [client]
> >
> > #password       = your_password
> >
> > port            = 3306
> >
> > socket          = /tmp/mysql.sock
> >
> >
> >
> > # Here follows entries for some specific programs
> >
> >
> >
> > # The MySQL server
> >
> > [mysqld]
> >
> > port            = 3306
> >
> > socket          = /tmp/mysql.sock
> >
> > skip-locking
> >
> > key_buffer_size = 16M
> >
> > max_allowed_packet = 1M
> >
> > table_open_cache = 64
> >
> > sort_buffer_size = 512K
> >
> > net_buffer_length = 8K
> >
> > read_buffer_size = 256K
> >
> > read_rnd_buffer_size = 512K
> >
> > myisam_sort_buffer_size = 8M
> >
> >
> >
> > # Don't listen on a TCP/IP port at all. This can be a security
> enhancement,
> >
> > # if all processes that need to connect to mysqld run on the same host.
> >
> > # All interaction with mysqld must be made via Unix sockets or named
> pipes.
> >
> > # Note that using this option without enabling named pipes on Windows
> >
> > # (via the "enable-named-pipe" option) will render mysqld useless!
> >
> > #
> >
> > #skip-networking
> >
> >
> >
> > # Replication Master Server (default)
> >
> > # binary logging is required for replication
> >
> > log-bin=mysql-bin
> >
> >
> >
> > # binary logging format - mixed recommended
> >
> > binlog_format=mixed
> >
> >
> >
> > # required unique id between 1 and 2^32 - 1
> >
> > # defaults to 1 if master-host is not set
> >
> > # but will not function as a master if omitted
> >
> > server-id       = 1
> >
> > --
> >
> > http://mail.python.org/mailman/listinfo/python-list
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From henryx_b at yahoo.it  Mon May  6 17:44:21 2013
From: henryx_b at yahoo.it (Enrico 'Henryx' Bianchi)
Date: Mon, 06 May 2013 23:44:21 +0200
Subject: python backup script
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
Message-ID: <km987m$99c$1@tdi.cu.mi.it>

MMZ wrote:

> config.read("~/my.cnf")
> username = config.get('client', 'mmz')
> password = config.get('client', 'pass1')
> hostname = config.get('client', 'localhost')

### A simple config file ###
[client]
user = mmz
password = pass1
host = localhost
### EOF ###

#!/usr/bin/env python
import ConfigParser

config = ConfigParser.ConfigParser()
config.read("~/configfile.cfg")
username = config.get('client', 'user')
password = config.get('client', 'password')
hostname = config.get('client', 'host')
[...]

> # Get a list of databases with :
> Database_list_command="mysql -u %s -p%s -h %s --silent -N -e 'show 
databases'" % (username, password, hostname)
> for database in os.popen(database_list_command).readlines():
>     database = database.strip()
>     if database == 'information_schema':
>         continue
>     if database == 'db_dev':
>         continue
>     filename = "/backups/mysql/%s-%s.sql" % (database, filestamp)
>     os.popen("mysqldump -u %s -p%s -h %s -e --opt -c %s | gzip -c > %s.gz" 
% (username, password, hostname, database, filename))

command = subprocess.Popen(['mysql', '-u ' + username,
                            '-p' + password, '-h ' + hostname,
                            '--silent', '-N', "-e 'show databases'"],
                            shell=False,
                            stdout=subprocess.PIPE)
status = command.wait()
for line in command.stdout.readlines():
    if line.strip() not in ['information_schema', 'db_dev']:
        filename = "/backups/mysql/%s-%s.sql" % (database, filestamp)
        cmd1  = subprocess.Popen(['mysqldump', '-u ' + username,
                            '-p' + password, '-h ' + hostname,
                            '-e', '--opt', '-c ' + database],
                            shell=False,
                            stdout=subprocess.PIPE)
        cmd2 =  subprocess.Popen(['gzip' '-c'],
                            shell=False,
                            stdout=filename)


Enrico


From henryx_b at yahoo.it  Mon May  6 17:48:44 2013
From: henryx_b at yahoo.it (Enrico 'Henryx' Bianchi)
Date: Mon, 06 May 2013 23:48:44 +0200
Subject: python backup script
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<km987m$99c$1@tdi.cu.mi.it>
Message-ID: <km98ft$99c$2@tdi.cu.mi.it>

Enrico 'Henryx' Bianchi wrote:

> cmd2 =  subprocess.Popen(['gzip' '-c'],
> shell=False,
> stdout=filename)

Doh, my fault:

cmd2 = subprocess.Popen(['gzip' '-c'],
                        shell=False,
                        stdout=filename
                        stdin=cmd1.stdout)

Enrico


From mina at socialassets.org  Mon May  6 18:12:59 2013
From: mina at socialassets.org (mina at socialassets.org)
Date: Mon, 6 May 2013 15:12:59 -0700 (PDT)
Subject: python backup script
In-Reply-To: <km98ft$99c$2@tdi.cu.mi.it>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<km987m$99c$1@tdi.cu.mi.it> <km98ft$99c$2@tdi.cu.mi.it>
Message-ID: <36d2b7cf-2537-46a6-b984-9fce7ddd33ff@googlegroups.com>

On Monday, May 6, 2013 5:48:44 PM UTC-4, Enrico 'Henryx' Bianchi wrote:
> Enrico 'Henryx' Bianchi wrote:
> 
> 
> 
> > cmd2 =  subprocess.Popen(['gzip' '-c'],
> 
> > shell=False,
> 
> > stdout=filename)
> 
> 
> 
> Doh, my fault:
> 
> 
> 
> cmd2 = subprocess.Popen(['gzip' '-c'],
> 
>                         shell=False,
> 
>                         stdout=filename
> 
>                         stdin=cmd1.stdout)
> 
> 
> 
> Enrico

Thank you Enrico. I've just tried your script and got this error:
 stdin=cmd1.stdout)
        ^
SyntaxError: invalid syntax

any idea?


From gordon at panix.com  Mon May  6 18:15:44 2013
From: gordon at panix.com (John Gordon)
Date: Mon, 6 May 2013 22:15:44 +0000 (UTC)
Subject: python backup script
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<km987m$99c$1@tdi.cu.mi.it> <km98ft$99c$2@tdi.cu.mi.it>
	<36d2b7cf-2537-46a6-b984-9fce7ddd33ff@googlegroups.com>
Message-ID: <km9a2g$jc$1@reader1.panix.com>

In <36d2b7cf-2537-46a6-b984-9fce7ddd33ff at googlegroups.com> mina at socialassets.org writes:

> > cmd2 = subprocess.Popen(['gzip' '-c'],
> > 
> >                         shell=False,
> > 
> >                         stdout=filename
> > 
> >                         stdin=cmd1.stdout)

> Thank you Enrico. I've just tried your script and got this error:
>  stdin=cmd1.stdout)
>         ^
> SyntaxError: invalid syntax

Looks like you need a comma after 'stdout=filename'.

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From henryx_b at yahoo.it  Tue May  7 15:11:22 2013
From: henryx_b at yahoo.it (Enrico 'Henryx' Bianchi)
Date: Tue, 07 May 2013 21:11:22 +0200
Subject: python backup script
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<km987m$99c$1@tdi.cu.mi.it> <km98ft$99c$2@tdi.cu.mi.it>
	<36d2b7cf-2537-46a6-b984-9fce7ddd33ff@googlegroups.com>
	<km9a2g$jc$1@reader1.panix.com>
Message-ID: <kmbjks$r4k$1@tdi.cu.mi.it>

John Gordon wrote:


> Looks like you need a comma after 'stdout=filename'.

Sigh, yesterday was a terrible day (yes, it lacks a comma)...
Anyway, when it is possible, is recommended to use the drivers for 
communicate with databases, because subprocess (or os.*open*) is more 
expensive compared to (python needs to spawn an external process to execute 
the command)

Enrico


From python at mrabarnett.plus.com  Mon May  6 18:28:07 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 06 May 2013 23:28:07 +0100
Subject: python backup script
In-Reply-To: <36d2b7cf-2537-46a6-b984-9fce7ddd33ff@googlegroups.com>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<km987m$99c$1@tdi.cu.mi.it> <km98ft$99c$2@tdi.cu.mi.it>
	<36d2b7cf-2537-46a6-b984-9fce7ddd33ff@googlegroups.com>
Message-ID: <51882E77.6010809@mrabarnett.plus.com>

On 06/05/2013 23:12, mina at socialassets.org wrote:
> On Monday, May 6, 2013 5:48:44 PM UTC-4, Enrico 'Henryx' Bianchi wrote:
>> Enrico 'Henryx' Bianchi wrote:
>>
>> > cmd2 =  subprocess.Popen(['gzip' '-c'],
>> > shell=False,
>> > stdout=filename)
>>
>> Doh, my fault:
>>
>> cmd2 = subprocess.Popen(['gzip' '-c'],
>>                         shell=False,
>>                         stdout=filename
>>                         stdin=cmd1.stdout)
>>
>> Enrico
>
> Thank you Enrico. I've just tried your script and got this error:
>   stdin=cmd1.stdout)
>          ^
> SyntaxError: invalid syntax
>
> any idea?
>
Missing comma on the previous line.



From programmer.toronto at gmail.com  Mon May  6 18:15:16 2013
From: programmer.toronto at gmail.com (MMZ)
Date: Mon, 6 May 2013 15:15:16 -0700 (PDT)
Subject: python backup script
In-Reply-To: <km98ft$99c$2@tdi.cu.mi.it>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<km987m$99c$1@tdi.cu.mi.it> <km98ft$99c$2@tdi.cu.mi.it>
Message-ID: <2c1e5a9b-cd5a-4fbf-9a09-bf2e566b83f3@googlegroups.com>


 stdin=cmd1.stdout)
        ^
SyntaxError: invalid syntax

On Monday, May 6, 2013 5:48:44 PM UTC-4, Enrico 'Henryx' Bianchi wrote:
> Enrico 'Henryx' Bianchi wrote:
> 
> 
> 
> > cmd2 =  subprocess.Popen(['gzip' '-c'],
> 
> > shell=False,
> 
> > stdout=filename)
> 
> 
> 
> Doh, my fault:
> 
> 
> 
> cmd2 = subprocess.Popen(['gzip' '-c'],
> 
>                         shell=False,
> 
>                         stdout=filename
> 
>                         stdin=cmd1.stdout)
> 
> 
> 
> Enrico



From rosuav at gmail.com  Mon May  6 18:12:28 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 7 May 2013 08:12:28 +1000
Subject: python backup script
In-Reply-To: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
Message-ID: <CAPTjJmoZWzQSDV4sE8nVq8bSeyx0M8UDCkxkmLbaOz2TXqxtBg@mail.gmail.com>

On Tue, May 7, 2013 at 5:01 AM, MMZ <programmer.toronto at gmail.com> wrote:
> username = config.get('client', 'mmz')
> password = config.get('client', 'pass1')
> hostname = config.get('client', 'localhost')

Are 'mmz', 'pass1', and 'localhost' the actual values you want for
username, password, and hostname? If so, don't pass them through
config.get() at all - just use them directly. In fact, I'd be inclined
to just stuff them straight into the Database_list_command literal;
that way, it's clear how they're used, and the fact that you aren't
escaping them in any way isn't going to be a problem (tip: an
apostrophe in your password would currently break your script).

It's also worth noting that the ~/ notation is a shell feature. You
may or may not be able to use it in config.read().

ChrisA


From __peter__ at web.de  Tue May  7 02:18:11 2013
From: __peter__ at web.de (Peter Otten)
Date: Tue, 07 May 2013 08:18:11 +0200
Subject: python backup script
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<CAPTjJmoZWzQSDV4sE8nVq8bSeyx0M8UDCkxkmLbaOz2TXqxtBg@mail.gmail.com>
Message-ID: <kma6av$e9m$1@ger.gmane.org>

Chris Angelico wrote:

> It's also worth noting that the ~/ notation is a shell feature. You
> may or may not be able to use it in config.read().

The latter. Combined with

"""
read(self, filenames) method of ConfigParser.ConfigParser instance
    Read and parse a filename or a list of filenames.
    
    Files that cannot be opened are silently ignored; this is
...
"""

you'll get no configuration at all. You have to apply

os.path.expanduser()

to get a valid path.

$ cd
$ touch tmp.config
$ cd /
$ python
Python 2.7.2+ (default, Jul 20 2012, 22:15:08) 
[GCC 4.6.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from ConfigParser import ConfigParser
>>> p = ConfigParser()
>>> p.read("~/tmp.config")
[]
>>> import os
>>> p.read(os.path.expanduser("~/tmp.config"))
['/home/peter/tmp.config']




From programmer.toronto at gmail.com  Mon May  6 18:40:40 2013
From: programmer.toronto at gmail.com (MMZ)
Date: Mon, 6 May 2013 15:40:40 -0700 (PDT)
Subject: python backup script
In-Reply-To: <mailman.1388.1367878356.3114.python-list@python.org>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<mailman.1388.1367878356.3114.python-list@python.org>
Message-ID: <f71a2143-a379-4c0c-9bdb-1a8b2cb15d79@googlegroups.com>

On Monday, May 6, 2013 6:12:28 PM UTC-4, Chris Angelico wrote:
> On Tue, May 7, 2013 at 5:01 AM, MMZ <programmer.toronto at gmail.com> wrote:
> 
> > username = config.get('client', 'mmz')
> 
> > password = config.get('client', 'pass1')
> 
> > hostname = config.get('client', 'localhost')
> 
> 
> 
> Are 'mmz', 'pass1', and 'localhost' the actual values you want for
> 
> username, password, and hostname? If so, don't pass them through
> 
> config.get() at all - just use them directly. In fact, I'd be inclined
> 
> to just stuff them straight into the Database_list_command literal;
> 
> that way, it's clear how they're used, and the fact that you aren't
> 
> escaping them in any way isn't going to be a problem (tip: an
> 
> apostrophe in your password would currently break your script).
> 
> 
> 
> It's also worth noting that the ~/ notation is a shell feature. You
> 
> may or may not be able to use it in config.read().
> 
> 
> 
> ChrisA

Thanks Chris. you are right.
So I used them directly and removed configParser. The new error is:

Traceback (most recent call last):
  File "./bbk.py", line 11, in ?
    for database in os.popen(database_list_command).readlines():
NameError: name 'database_list_command' is not defined

any idea?


From rosuav at gmail.com  Mon May  6 18:51:56 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 7 May 2013 08:51:56 +1000
Subject: python backup script
In-Reply-To: <f71a2143-a379-4c0c-9bdb-1a8b2cb15d79@googlegroups.com>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<mailman.1388.1367878356.3114.python-list@python.org>
	<f71a2143-a379-4c0c-9bdb-1a8b2cb15d79@googlegroups.com>
Message-ID: <CAPTjJmrJSmgVTP2T1+S=6MJ_++CRgA3bfu=EE6uMXqzpp2LGtA@mail.gmail.com>

On Tue, May 7, 2013 at 8:40 AM, MMZ <programmer.toronto at gmail.com> wrote:
> Thanks Chris. you are right.
> So I used them directly and removed configParser. The new error is:
>
> Traceback (most recent call last):
>   File "./bbk.py", line 11, in ?
>     for database in os.popen(database_list_command).readlines():
> NameError: name 'database_list_command' is not defined

Python names are case-sensitive. If you create it with a capital D,
you can't reference it with a lower-case d. For consistency with the
rest of your code, I'd advise lowercasing it.

ChrisA


From python at mrabarnett.plus.com  Mon May  6 18:52:53 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 06 May 2013 23:52:53 +0100
Subject: python backup script
In-Reply-To: <f71a2143-a379-4c0c-9bdb-1a8b2cb15d79@googlegroups.com>
References: <b586db98-78b2-40a6-9e1c-3d8b939657c8@googlegroups.com>
	<mailman.1388.1367878356.3114.python-list@python.org>
	<f71a2143-a379-4c0c-9bdb-1a8b2cb15d79@googlegroups.com>
Message-ID: <51883445.8080506@mrabarnett.plus.com>

On 06/05/2013 23:40, MMZ wrote:
> On Monday, May 6, 2013 6:12:28 PM UTC-4, Chris Angelico wrote:
>> On Tue, May 7, 2013 at 5:01 AM, MMZ <programmer.toronto at gmail.com> wrote:
>>
>> > username = config.get('client', 'mmz')
>>
>> > password = config.get('client', 'pass1')
>>
>> > hostname = config.get('client', 'localhost')
>>
>>
>>
>> Are 'mmz', 'pass1', and 'localhost' the actual values you want for
>>
>> username, password, and hostname? If so, don't pass them through
>>
>> config.get() at all - just use them directly. In fact, I'd be inclined
>>
>> to just stuff them straight into the Database_list_command literal;
>>
>> that way, it's clear how they're used, and the fact that you aren't
>>
>> escaping them in any way isn't going to be a problem (tip: an
>>
>> apostrophe in your password would currently break your script).
>>
>>
>>
>> It's also worth noting that the ~/ notation is a shell feature. You
>>
>> may or may not be able to use it in config.read().
>>
>>
>>
>> ChrisA
>
> Thanks Chris. you are right.
> So I used them directly and removed configParser. The new error is:
>
> Traceback (most recent call last):
>    File "./bbk.py", line 11, in ?
>      for database in os.popen(database_list_command).readlines():
> NameError: name 'database_list_command' is not defined
>
> any idea?
>
Check the spelling (remember that the name is case-sensitive).


From svenito at gmail.com  Mon May  6 16:57:01 2013
From: svenito at gmail.com (Sven)
Date: Mon, 6 May 2013 21:57:01 +0100
Subject: PIL: check if image is animated
Message-ID: <CAEH=cXW9Vtu2xGkppOutkqBs6nXVTKSQLPWza_FcvXnjxNJL+Q@mail.gmail.com>

Hello,

I am trying to check if an image is animated. I can't rely on the extension
as it may be a gif that's been renamed to .jpg or something else and is
still animated.

I thought that this used to work:

from PIL import Image


def check_animated(img):
    try:
        img.seek(1)
    except (EOFError):
        return 0
    return 1

img = Image('image.jpg')
print "animated?", check_animated(img)

Regardless if it's animated or not I get this exception:
ValueError: cannot seek to frame 1

I need to return 0 or 1, so excuse not using True or False.

Did the above get deprecated/change in a version at some point? Perhaps
there's something I missed during install (using PIP). Are there any other
ways to accomplish what I am trying to do, with or without PIL?

Python 2.7, linux

-- 
./Sven
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From svenito at gmail.com  Thu May  9 04:22:49 2013
From: svenito at gmail.com (Sven)
Date: Thu, 9 May 2013 09:22:49 +0100
Subject: PIL: check if image is animated
In-Reply-To: <CAEH=cXW9Vtu2xGkppOutkqBs6nXVTKSQLPWza_FcvXnjxNJL+Q@mail.gmail.com>
References: <CAEH=cXW9Vtu2xGkppOutkqBs6nXVTKSQLPWza_FcvXnjxNJL+Q@mail.gmail.com>
Message-ID: <CAEH=cXVPiQnLb3T96XvziDeUP7CzQNz-p+9j3QqW-vmSnMoaLA@mail.gmail.com>

Figured out my issue. I did called the check_animated function more than
once and the second call causes the exception unless I seek back to 0


On 6 May 2013 21:57, Sven <svenito at gmail.com> wrote:

> Hello,
>
> I am trying to check if an image is animated. I can't rely on the
> extension as it may be a gif that's been renamed to .jpg or something else
> and is still animated.
>
> I thought that this used to work:
>
> from PIL import Image
>
>
> def check_animated(img):
>     try:
>         img.seek(1)
>     except (EOFError):
>         return 0
>     return 1
>
> img = Image('image.jpg')
> print "animated?", check_animated(img)
>
> Regardless if it's animated or not I get this exception:
> ValueError: cannot seek to frame 1
>
> I need to return 0 or 1, so excuse not using True or False.
>
> Did the above get deprecated/change in a version at some point? Perhaps
> there's something I missed during install (using PIP). Are there any other
> ways to accomplish what I am trying to do, with or without PIL?
>
> Python 2.7, linux
>
> --
> ./Sven
>



-- 
./Sven
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From livewebcamsexs at gmail.com  Tue May  7 01:04:07 2013
From: livewebcamsexs at gmail.com (MoneyMaker)
Date: Mon, 6 May 2013 22:04:07 -0700 (PDT)
Subject: Horror!!!!
Message-ID: <e3558bc2-fc07-4b42-807e-ca19ca3faff3@googlegroups.com>

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From info at egenix.com  Tue May  7 04:01:05 2013
From: info at egenix.com (eGenix Team: M.-A. Lemburg)
Date: Tue, 07 May 2013 10:01:05 +0200
Subject: ANN: eGenix mxODBC Zope/Plone Database Adapter 2.1.2
Message-ID: <5188B4C1.9010901@egenix.com>

________________________________________________________________________

ANNOUNCEMENT

                  mxODBC Zope/Plone Database Adapter

                            Version 2.1.2

                     for Zope and the Plone CMS

                Available for Plone 4.0, 4.1 and 4.2,
                        Zope 2.12 and 2.13, on
        Windows, Linux, Mac OS X, FreeBSD and other platforms

This announcement is also available on our web-site for online reading:
http://www.egenix.com/company/news/eGenix-mxODBC-Zope-DA-2.1.2-GA.html

________________________________________________________________________

INTRODUCTION

The eGenix mxODBC Zope DA allows you to easily connect your Zope or
Plone CMS installation to just about any database backend on the
market today, giving you the reliability of the commercially supported
eGenix product mxODBC and the flexibility of the ODBC standard as
middle-tier architecture.

The mxODBC Zope Database Adapter is highly portable, just like Zope
itself and provides a high performance interface to all your ODBC data
sources, using a single well-supported interface on Windows, Linux,
Mac OS X, FreeBSD and other platforms.

This makes it ideal for deployment in ZEO Clusters and Zope hosting
environments where stability and high performance are a top priority,
establishing an excellent basis and scalable solution for your Plone
CMS.

Product page:

    http://www.egenix.com/products/zope/mxODBCZopeDA/

________________________________________________________________________

NEWS

We are pleased to announce the new version 2.1.2 of our mxODBC
Zope/Plone Database Adapter product.

Compatibility Enhancements
--------------------------

 * Added a work-around for a regression in Python 2.7.4 that results
   in a segfault when exiting Zope/Plone after loading the mxODBC Zope
   DA.

   The regression will be fixed in Python 2.7.5, but we don't want to
   expose our users to segfaults, so added a work-around.

   See http://bugs.python.org/issue17703 for the bug ticket.

 * Upgraded the underlying mxODBC library to version 3.2.3. Please see
   the mxODBC 3.2.3 release announcement for additional details:

   http://www.egenix.com/company/news/eGenix-mxODBC-3.2.3-GA.html


Driver Compatibility
--------------------

 * Please also see the mxODBC Zope DA 2.1.1 announcement for an
   important new feature which allows to dramatically increase the
   fetch performance when working with MS SQL Server and IBM DB2
   databases.

   http://www.egenix.com/company/news/eGenix-mxODBC-Zope-DA-2.1.1-GA.html


For the full set of changes please check the change log:

    http://www.egenix.com/products/zope/mxODBCZopeDA/changelog.html

________________________________________________________________________

FEATURES

Version 2.1.0 of our mxODBC Zope/Plone Database Adapter product was
released on 2012-09-18. Please see the announcement for highlights of
the 2.1 release:

    http://www.egenix.com/company/news/eGenix-mxODBC-Zope-DA-2.1.0-GA.html

For the full set of features mxODBC Zope DA has to offer, please see:

    http://www.egenix.com/products/zope/mxODBCZopeDA/#Features

________________________________________________________________________

UPGRADING

Users are encouraged to upgrade to this latest mxODBC Zope/Plone DA
release to benefit from the new features and updated ODBC driver
support.

We have taken special care not to introduce backwards incompatible
changes, making the upgrade experience as smooth as possible.

As always, patch level upgrades (e.g. from 2.1.0 to 2.1.2) are free of
charge. The licenses you have purchased for 2.1 will continue to work
with this new release.

For major and minor upgrade purchases, we will give out 20% discount
coupons going from mxODBC Zope DA 1.x to 2.1 and 50% coupons for
upgrades from mxODBC 2.x to 2.1. After upgrade, use of the original
license from which you upgraded is no longer permitted.

Please contact the eGenix.com Sales Team with your existing license
serials for details for an upgrade discount coupon.

If you want to try the new release before purchase, you can request
30-day evaluation licenses by visiting our web-site or writing to
sales at egenix.com, stating your name (or the name of the company) and
the number of evaluation licenses that you need.

_______________________________________________________________________

SUPPORT

Commercial support for this product is available from eGenix.com.
Please see

    http://www.egenix.com/services/support/

for details about our support offerings.

________________________________________________________________________

MORE INFORMATION

For more information on the mxODBC Zope Database Adapter, licensing
and download instructions, please visit our web-site:

    http://www.egenix.com/products/zope/mxODBCZopeDA/

You can buy mxODBC Zope DA licenses online from the eGenix.com shop at:

    http://shop.egenix.com/

About Python (http://www.python.org/):

    Python is an object-oriented Open Source programming language
    which runs on all modern platforms. By integrating ease-of-use,
    clarity in coding, enterprise application connectivity and rapid
    application design, Python establishes an ideal programming
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About eGenix (http://www.egenix.com/):

    eGenix is a software project, consulting and product company
    focusing on expert project services and professional quality
    products for companies, Python users and developers.

Enjoy,
-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Source  (#1, May 07 2013)
>>> Python Projects, Consulting and Support ...   http://www.egenix.com/
>>> mxODBC.Zope/Plone.Database.Adapter ...       http://zope.egenix.com/
>>> mxODBC, mxDateTime, mxTextTools ...        http://python.egenix.com/
________________________________________________________________________
2013-05-06: Released mxODBC 3.2.3 ...             http://egenix.com/go45
2013-04-30: Released eGenix PyRun 1.2.0 ...       http://egenix.com/go44

::::: Try our mxODBC.Connect Python Database Interface for free ! ::::::

   eGenix.com Software, Skills and Services GmbH  Pastor-Loeh-Str.48
    D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg
           Registered at Amtsgericht Duesseldorf: HRB 46611
               http://www.egenix.com/company/contact/


From cheirasacan at gmail.com  Tue May  7 05:27:42 2013
From: cheirasacan at gmail.com (cheirasacan at gmail.com)
Date: Tue, 7 May 2013 02:27:42 -0700 (PDT)
Subject: Why sfml does not play the file inside a function in this python code?
Message-ID: <69b77965-5ff5-4c6f-a73d-0826b06353f0@googlegroups.com>

from tkinter import *
import sfml


window = Tk()
window.minsize( 640, 480 )


def sonido():
    file = sfml.Music.from_file('poco.ogg')
    file.play()


test = Button ( window, text = 'Sound test', command=sonido )
test.place ( x = 10, y = 60)

window.mainloop()




Using Windows 7, Python 3.3, sfml 1.3.0 library, the file it is played if i put it out of the function. ? what am i doing wrong ? Thanks.


From python at mrabarnett.plus.com  Tue May  7 06:53:25 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 07 May 2013 11:53:25 +0100
Subject: Why sfml does not play the file inside a function in this python
	code?
In-Reply-To: <69b77965-5ff5-4c6f-a73d-0826b06353f0@googlegroups.com>
References: <69b77965-5ff5-4c6f-a73d-0826b06353f0@googlegroups.com>
Message-ID: <5188DD25.3070107@mrabarnett.plus.com>

On 07/05/2013 10:27, cheirasacan at gmail.com wrote:
> from tkinter import *
> import sfml
>
>
> window = Tk()
> window.minsize( 640, 480 )
>
>
> def sonido():
>      file = sfml.Music.from_file('poco.ogg')
>      file.play()
>
>
> test = Button ( window, text = 'Sound test', command=sonido )
> test.place ( x = 10, y = 60)
>
> window.mainloop()
>
>
>
>
> Using Windows 7, Python 3.3, sfml 1.3.0 library, the file it is played if i put it out of the function. ? what am i doing wrong ? Thanks.
>
Perhaps what's happening is that sonido starts playing it and then
returns, meaning that there's no longer a reference to it ('file' is
local to the function), so it's collected by the garbage collector.

If that's the case, try keeping a reference to it, perhaps by making
'file' global (in a simple program like this one, using global should
be OK).



From cheirasacan at gmail.com  Tue May  7 09:56:28 2013
From: cheirasacan at gmail.com (cheirasacan at gmail.com)
Date: Tue, 7 May 2013 06:56:28 -0700 (PDT)
Subject: Why sfml does not play the file inside a function in this python
	code?
In-Reply-To: <mailman.1402.1367924006.3114.python-list@python.org>
References: <69b77965-5ff5-4c6f-a73d-0826b06353f0@googlegroups.com>
	<mailman.1402.1367924006.3114.python-list@python.org>
Message-ID: <85771dda-4289-4cfb-a96f-23809664913e@googlegroups.com>

El martes, 7 de mayo de 2013 12:53:25 UTC+2, MRAB  escribi?:
> On 07/05/2013 10:27, cheirasacan at gmail.com wrote:
> 
> > from tkinter import *
> 
> > import sfml
> 
> >
> 
> >
> 
> > window = Tk()
> 
> > window.minsize( 640, 480 )
> 
> >
> 
> >
> 
> > def sonido():
> 
> >      file = sfml.Music.from_file('poco.ogg')
> 
> >      file.play()
> 
> >
> 
> >
> 
> > test = Button ( window, text = 'Sound test', command=sonido )
> 
> > test.place ( x = 10, y = 60)
> 
> >
> 
> > window.mainloop()
> 
> >
> 
> >
> 
> >
> 
> >
> 
> > Using Windows 7, Python 3.3, sfml 1.3.0 library, the file it is played if i put it out of the function. ??? what am i doing wrong ? Thanks.
> 
> >
> 
> Perhaps what's happening is that sonido starts playing it and then
> 
> returns, meaning that there's no longer a reference to it ('file' is
> 
> local to the function), so it's collected by the garbage collector.
> 
> 
> 
> If that's the case, try keeping a reference to it, perhaps by making
> 
> 'file' global (in a simple program like this one, using global should
> 
> be OK).

Thanks. A global use of 'sonido' fix the problem. The garbage collector must be the point. But this code is part of a longer project. What can i do to fix it without the use of globals? I will use more functions like this, and i would like to keep learning python as well good programming methodology.
Thanks.


From python at mrabarnett.plus.com  Tue May  7 10:57:59 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 07 May 2013 15:57:59 +0100
Subject: Why sfml does not play the file inside a function in this python
	code?
In-Reply-To: <85771dda-4289-4cfb-a96f-23809664913e@googlegroups.com>
References: <69b77965-5ff5-4c6f-a73d-0826b06353f0@googlegroups.com>
	<mailman.1402.1367924006.3114.python-list@python.org>
	<85771dda-4289-4cfb-a96f-23809664913e@googlegroups.com>
Message-ID: <51891677.1020009@mrabarnett.plus.com>

On 07/05/2013 14:56, cheirasacan at gmail.com wrote:
> El martes, 7 de mayo de 2013 12:53:25 UTC+2, MRAB  escribi?:
>> On 07/05/2013 10:27, cheirasacan at gmail.com wrote:
>> > from tkinter import *
>> > import sfml
>> >
>> > window = Tk()
>> > window.minsize( 640, 480 )
>> >
>> > def sonido():
>> >      file = sfml.Music.from_file('poco.ogg')
>> >      file.play()
>> >
>> > test = Button ( window, text = 'Sound test', command=sonido )
>> > test.place ( x = 10, y = 60)
>> >
>> > window.mainloop()
>> >
>> > Using Windows 7, Python 3.3, sfml 1.3.0 library, the file it is played if i put it out of the function. ??? what am i doing wrong ? Thanks.
>> >
>>
>> Perhaps what's happening is that sonido starts playing it and then
>> returns, meaning that there's no longer a reference to it ('file' is
>> local to the function), so it's collected by the garbage collector.
>>
>> If that's the case, try keeping a reference to it, perhaps by making
>> 'file' global (in a simple program like this one, using global should
>> be OK).
>
> Thanks. A global use of 'sonido' fix the problem. The garbage collector must be the point. But this code is part of a longer project. What can i do to fix it without the use of globals? I will use more functions like this, and i would like to keep learning python as well good programming methodology.
> Thanks.
>
Presumably the details of the window are (or will be) hidden away in a
class, so you could make 'file' an attribute of an instance.

Also, please read this:

http://wiki.python.org/moin/GoogleGroupsPython

because gmail insists on adding extra linebreaks, which can be somewhat
annoying.


From rosuav at gmail.com  Tue May  7 11:06:24 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 8 May 2013 01:06:24 +1000
Subject: Why sfml does not play the file inside a function in this python
	code?
In-Reply-To: <51891677.1020009@mrabarnett.plus.com>
References: <69b77965-5ff5-4c6f-a73d-0826b06353f0@googlegroups.com>
	<mailman.1402.1367924006.3114.python-list@python.org>
	<85771dda-4289-4cfb-a96f-23809664913e@googlegroups.com>
	<51891677.1020009@mrabarnett.plus.com>
Message-ID: <CAPTjJmrPvimvL1=eT4AoJAYU00pUPzbFvwLJNO=kxjYh1ykkQA@mail.gmail.com>

On Wed, May 8, 2013 at 12:57 AM, MRAB <python at mrabarnett.plus.com> wrote:
> Also, please read this:
>
> http://wiki.python.org/moin/GoogleGroupsPython
>
> because gmail insists on adding extra linebreaks, which can be somewhat
> annoying.

Accuracy correction: It's nothing to do with gmail, which is what I
use (via python-list subscription). It's just Google Groups.

ChrisA


From vincent.vandevyvre at swing.be  Tue May  7 13:03:00 2013
From: vincent.vandevyvre at swing.be (Vincent Vande Vyvre)
Date: Tue, 07 May 2013 19:03:00 +0200
Subject: dist-packages or site-packages  in Python 3.2 ?
In-Reply-To: <CAPTjJmrPvimvL1=eT4AoJAYU00pUPzbFvwLJNO=kxjYh1ykkQA@mail.gmail.com>
References: <69b77965-5ff5-4c6f-a73d-0826b06353f0@googlegroups.com>
	<mailman.1402.1367924006.3114.python-list@python.org>
	<85771dda-4289-4cfb-a96f-23809664913e@googlegroups.com>
	<51891677.1020009@mrabarnett.plus.com>
	<CAPTjJmrPvimvL1=eT4AoJAYU00pUPzbFvwLJNO=kxjYh1ykkQA@mail.gmail.com>
Message-ID: <518933C4.1050808@swing.be>

Hi,

I've one machine with python3.2 (on Ubuntu 12.04), in the folder 
/usr/lib/python3.2 it is a subfolder dist-packages, maybe created at the 
install or created when I've installed the binding pyexiv2, I don't know.

Now, I've installed a new machine, again with Ubuntu 12.04 and therefore 
python3.2.
This new install hasn't any *-packages subfolder in /usr/lib/python3.2

Today I install PyQt5, the make and make install are executed without 
error but when I try:

 >>> from PyQt5 import QtGui
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
ImportError: No module named PyQt5

I go to check in /usr/lib/python3.2 and I see the install of PyQt5 has 
created a subfolder site-packages.
Is this naming dist-packages/site-packages critical for Python? (My 
intuition is yes!)

So, I've tried with:
 >>> sys.path.append('/usr/lib/python3.2/site_packages')
and, also, created a file __init__.py in /site-packages but that's not 
solved the problem.

Thanks for your advices.
-- 
Vincent V.V.
Oqapy <https://launchpad.net/oqapy> . Qarte 
<https://launchpad.net/qarte> . PaQager <https://launchpad.net/paqager>


From cheirasacan at gmail.com  Tue May  7 16:02:00 2013
From: cheirasacan at gmail.com (cheirasacan at gmail.com)
Date: Tue, 7 May 2013 13:02:00 -0700 (PDT)
Subject: Why sfml does not play the file inside a function in this python
	code?
In-Reply-To: <mailman.1413.1367938681.3114.python-list@python.org>
References: <69b77965-5ff5-4c6f-a73d-0826b06353f0@googlegroups.com>
	<mailman.1402.1367924006.3114.python-list@python.org>
	<85771dda-4289-4cfb-a96f-23809664913e@googlegroups.com>
	<mailman.1413.1367938681.3114.python-list@python.org>
Message-ID: <6339279e-4f8e-43c8-bb04-b6607d7db4a1@googlegroups.com>

El martes, 7 de mayo de 2013 16:57:59 UTC+2, MRAB  escribi?:
> On 07/05/2013 14:56, cheirasacan at gmail.com wrote:
> 
> > El martes, 7 de mayo de 2013 12:53:25 UTC+2, MRAB  escribi?:
> 
> >> On 07/05/2013 10:27, cheirasacan at gmail.com wrote:
> 
> >> > from tkinter import *
> 
> >> > import sfml
> 
> >> >
> 
> >> > window = Tk()
> 
> >> > window.minsize( 640, 480 )
> 
> >> >
> 
> >> > def sonido():
> 
> >> >      file = sfml.Music.from_file('poco.ogg')
> 
> >> >      file.play()
> 
> >> >
> 
> >> > test = Button ( window, text = 'Sound test', command=sonido )
> 
> >> > test.place ( x = 10, y = 60)
> 
> >> >
> 
> >> > window.mainloop()
> 
> >> >
> 
> >> > Using Windows 7, Python 3.3, sfml 1.3.0 library, the file it is played if i put it out of the function. ??? what am i doing wrong ? Thanks.
> 
> >> >
> 
> >>
> 
> >> Perhaps what's happening is that sonido starts playing it and then
> 
> >> returns, meaning that there's no longer a reference to it ('file' is
> 
> >> local to the function), so it's collected by the garbage collector.
> 
> >>
> 
> >> If that's the case, try keeping a reference to it, perhaps by making
> 
> >> 'file' global (in a simple program like this one, using global should
> 
> >> be OK).
> 
> >
> 
> > Thanks. A global use of 'sonido' fix the problem. The garbage collector must be the point. But this code is part of a longer project. What can i do to fix it without the use of globals? I will use more functions like this, and i would like to keep learning python as well good programming methodology.
> 
> > Thanks.
> 
> >
> 
> Presumably the details of the window are (or will be) hidden away in a
> 
> class, so you could make 'file' an attribute of an instance.
> 
> 
> 
> Also, please read this:
> 
> 
> 
> http://wiki.python.org/moin/GoogleGroupsPython
> 
> 
> 
> because gmail insists on adding extra linebreaks, which can be somewhat
> 
> annoying.

 The reply is very useful. I will keep learning.
 Thanks for all.


From robin at reportlab.com  Tue May  7 07:02:38 2013
From: robin at reportlab.com (Robin Becker)
Date: Tue, 07 May 2013 12:02:38 +0100
Subject: unexpected syntax errors
Message-ID: <5188DF4E.3020801@chamonix.reportlab.co.uk>

A user is getting this error

>
> New issue 8: bad raise syntax
> https://bitbucket.org/rptlab/reportlab/issue/8/bad-raise-syntax
>
> ........
>
>   File "/usr/lib/python2.7/site-packages/svg2rlg.py", line 16, in <module>
>     from reportlab.graphics import renderPDF
>   File "/usr/lib64/python2.7/site-packages/reportlab/graphics/renderPDF.py", line 168
>     raise ValueError, 'bad value for textAnchor '+str(text_anchor)
>                     ^
> SyntaxError: invalid syntax
>
>

however, I believe that this older syntax is allowed in python 2.7. We've had 
other issues like this raised from various distros which are apparently making 
changes to 2.7 which change the external behaviour eg spelling corrections to 
attribute names. Could this be one of those?
-- 
Robin Becker



From redstone-cold at 163.com  Tue May  7 07:15:38 2013
From: redstone-cold at 163.com (iMath)
Date: Tue, 7 May 2013 04:15:38 -0700 (PDT)
Subject: use python to split a video file into a set of parts
Message-ID: <b42ca928-ec8d-4388-adc6-df48b246e275@googlegroups.com>

I use the following python code to split a FLV video file into a set of parts ,when finished ,only the first part video can be played ,the other parts are corrupted.I wonder why and Is there some correct ways to split video files

import sys, os
kilobytes = 1024
megabytes = kilobytes * 1000
chunksize = int(1.4 * megabytes)                   # default: roughly a floppy

print(chunksize , type(chunksize ))

def split(fromfile, todir, chunksize=chunksize):
    if not os.path.exists(todir):                  # caller handles errors
        os.mkdir(todir)                            # make dir, read/write parts
    else:
        for fname in os.listdir(todir):            # delete any existing files
            os.remove(os.path.join(todir, fname))
    partnum = 0
    input = open(fromfile, 'rb')                   # use binary mode on Windows
    while True:                                    # eof=empty string from read
        chunk = input.read(chunksize)              # get next part <= chunksize
        if not chunk: break
        partnum += 1
        filename = os.path.join(todir, ('part{}.flv'.format(partnum)))
        fileobj  = open(filename, 'wb')
        fileobj.write(chunk)
        fileobj.close()                            # or simply open().write()
    input.close()
    assert partnum <= 9999                         # join sort fails if 5 digits
    return partnum

if __name__ == '__main__':

    fromfile = input('File to be split? ')           # input if clicked
    todir    = input('Directory to store part files?')
    print('Splitting', fromfile, 'to', todir, 'by', chunksize)
    parts = split(fromfile, todir, chunksize)
    print('Split finished:', parts, 'parts are in', todir)


From rosuav at gmail.com  Tue May  7 08:00:10 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 7 May 2013 22:00:10 +1000
Subject: use python to split a video file into a set of parts
In-Reply-To: <b42ca928-ec8d-4388-adc6-df48b246e275@googlegroups.com>
References: <b42ca928-ec8d-4388-adc6-df48b246e275@googlegroups.com>
Message-ID: <CAPTjJmrBJF-X4mu1d2-t-HhSK7=M48ve7s6927x1nju+4R4wzA@mail.gmail.com>

On Tue, May 7, 2013 at 9:15 PM, iMath <redstone-cold at 163.com> wrote:
> I use the following python code to split a FLV video file into a set of parts ,when finished ,only the first part video can be played ,the other parts are corrupted.I wonder why and Is there some correct ways to split video files

Most complex files of this nature have headers. You're chunking it in
pure bytes, so chances are you're disrupting that. The only thing you
can reliably do with your chunks is recombine them into the original
file.

> import sys, os
> kilobytes = 1024
> megabytes = kilobytes * 1000
> chunksize = int(1.4 * megabytes)                   # default: roughly a floppy

Hrm. Firstly, this is a very small chunksize for today's files. You
hard-fail any file more than about 13GB, and for anything over a gig,
you're looking at a thousand files or more. Secondly, why are you
working with 1024 at the first level and 1000 at the second? You're
still a smidge short of the 1440KB that was described as 1.44MB, and
you have the same error of unit. Stick to binary kay OR decimal kay,
don't mix and match!

> print(chunksize , type(chunksize ))

Since you passed chunksize through the int() constructor, you can be
fairly confident it'll be an int :)

> def split(fromfile, todir, chunksize=chunksize):
>     if not os.path.exists(todir):                  # caller handles errors
>         os.mkdir(todir)                            # make dir, read/write parts
>     else:
>         for fname in os.listdir(todir):            # delete any existing files
>             os.remove(os.path.join(todir, fname))

Tip: Use os.mkdirs() in case some of its parents need to be made. And
if you wrap it in try/catch rather than probing first, you eliminate a
race condition. (By the way, it's pretty dangerous to just delete
files from someone else's directory. I would recommend aborting with
an error if you absolutely must work with an empty directory.)

>     input = open(fromfile, 'rb')                   # use binary mode on Windows

As a general rule I prefer to avoid shadowing builtins, but it's not
strictly a problem.

>         filename = os.path.join(todir, ('part{}.flv'.format(partnum)))
>     assert partnum <= 9999                         # join sort fails if 5 digits
>     return partnum

Why the assertion? Since this is all you do with the partnum, why does
it matter how long the number is? Without seeing the join sort I can't
know why that would fail; but there must surely be a solution to this.

>     fromfile = input('File to be split? ')           # input if clicked

"clicked"? I'm guessing this is a translation problem, but I've no
idea what you mean by it.

What you have seems to be a reasonably viable (not that I tested it or
anything) file-level split. You should be able to re-join the parts
quite easily. But the subsequent parts are highly unlikely to play.
Even if you were working in a format that had no headers and could
resynchronize, chances are a 1.4MB file won't have enough to play
anything. Consider: A 1280x720 image contains 921,600 pixels;
uncompressed, this would take 2-4 bytes per pixel, depending on color
depth. To get a single playable frame, you would need an i-frame (ie
not a difference frame) to start and end within a single 1.4MB unit;
it would need to compress 50-75% just to fit, and that's assuming
optimal placement. With random placement, you would need to be getting
87% compression on your index frames, and then you'd still get just
one frame inside your chunk. That's not likely to be very playable.

But hey. You can stitch 'em back together again :)

ChrisA


From davea at davea.name  Tue May  7 08:10:08 2013
From: davea at davea.name (Dave Angel)
Date: Tue, 07 May 2013 08:10:08 -0400
Subject: use python to split a video file into a set of parts
In-Reply-To: <b42ca928-ec8d-4388-adc6-df48b246e275@googlegroups.com>
References: <b42ca928-ec8d-4388-adc6-df48b246e275@googlegroups.com>
Message-ID: <5188EF20.5080301@davea.name>

On 05/07/2013 07:15 AM, iMath wrote:
> I use the following python code to split a FLV video file into a set of parts ,when finished ,only the first part video can be played ,the other parts are corrupted.I wonder why and Is there some correct ways to split video files
>

There are two parts to answering the question.  First, did it accurately 
chunk the file into separate pieces.  That should be trivial to test -- 
simply concatenate them back together (eg. using copy /b) and make sure 
you get exactly the original.  (using md5sum, for example) I think you will.

And second, why the arbitrary pieces don't play in some unspecified 
video player.  That one's more interesting, but hasn't anything to do 
with Python.  I'm curious why you would expect that it would play.  It 
won't have any of the header information, and the compressed data will 
be missing its context information.  To split apart a binary file into 
useful pieces requires a lot of knowledge about the file format.



-- 
DaveA


From sjo.india at gmail.com  Tue May  7 08:00:21 2013
From: sjo.india at gmail.com (Sudheer Joseph)
Date: Tue, 7 May 2013 05:00:21 -0700 (PDT)
Subject: formatted output
Message-ID: <add22437-64a4-4dfb-b6d9-28832e7698b4@googlegroups.com>

Dear members,
            I need to print few arrays in a tabular form for example below array IL has 25 elements, is there an easy way to print this as 5x5 comma separated table? in python

IL=[]
for i in np.arange(1,bno+1):
       IL.append(i)
print(IL)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
in fortran I could do it as below
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
integer matrix(5,5)
       in=0
      do, k=1,5
      do, l=1,5
       in=in+1
      matrix(k,l)=in
      enddo
      enddo
      m=5
      n=5
      do, i=1,m
      write(*,"(5i5)") ( matrix(i,j), j=1,n )
      enddo
      end
 


From roy at panix.com  Tue May  7 08:42:21 2013
From: roy at panix.com (Roy Smith)
Date: Tue, 07 May 2013 08:42:21 -0400
Subject: formatted output
References: <add22437-64a4-4dfb-b6d9-28832e7698b4@googlegroups.com>
Message-ID: <roy-8514D9.08422007052013@news.panix.com>

In article <add22437-64a4-4dfb-b6d9-28832e7698b4 at googlegroups.com>,
 Sudheer Joseph <sjo.india at gmail.com> wrote:

> Dear members,
>             I need to print few arrays in a tabular form for example below 
>             array IL has 25 elements, is there an easy way to print this as 
>             5x5 comma separated table? in python
> 
> IL=[]
> for i in np.arange(1,bno+1):
>        IL.append(i)
> print(IL)
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> in fortran I could do it as below
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> integer matrix(5,5)
>        in=0
>       do, k=1,5
>       do, l=1,5
>        in=in+1
>       matrix(k,l)=in
>       enddo
>       enddo
>       m=5
>       n=5
>       do, i=1,m
>       write(*,"(5i5)") ( matrix(i,j), j=1,n )
>       enddo
>       end
>  

Excellent.  My kind of programming language!  See 
http://www.python.org/doc/humor/#bad-habits.

Anyway, that translates, more or less, as follows.

Note that I'm modeling the Fortran 2-dimensional array as a dictionary 
keyed by (k, l) tuples.  That's easy an convenient, but conceptually a 
poor fit and not terribly efficient.  If efficiency is an issue (i.e. 
much larger values of (k, l), you probably want to be looking at numpy.

Also, "in" is a keyword in python, so I changed that to "value".  
There's probably cleaner ways to do this. I did a pretty literal 
transliteration.


matrix = {}
value = 0
for k in range(1, 6):
   for l in range(1, 6):
      value += 1
      matrix[(k, l)] = value

for i in range(1, 6):
   print ",".join("%5d" % matrix[(i, j)] for j in range(1, 6))

This prints:

    1,    2,    3,    4,    5
    6,    7,    8,    9,   10
   11,   12,   13,   14,   15
   16,   17,   18,   19,   20
   21,   22,   23,   24,   25


From __peter__ at web.de  Tue May  7 09:28:27 2013
From: __peter__ at web.de (Peter Otten)
Date: Tue, 07 May 2013 15:28:27 +0200
Subject: formatted output
References: <add22437-64a4-4dfb-b6d9-28832e7698b4@googlegroups.com>
	<roy-8514D9.08422007052013@news.panix.com>
Message-ID: <kmavhl$ogl$1@ger.gmane.org>

Roy Smith wrote:

> In article <add22437-64a4-4dfb-b6d9-28832e7698b4 at googlegroups.com>,
>  Sudheer Joseph <sjo.india at gmail.com> wrote:
> 
>> Dear members,
>>             I need to print few arrays in a tabular form for example
>>             below array IL has 25 elements, is there an easy way to print
>>             this as 5x5 comma separated table? in python
>> 
>> IL=[]
>> for i in np.arange(1,bno+1):
>>        IL.append(i)
>> print(IL)
>> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>> in fortran I could do it as below
>> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>> integer matrix(5,5)
>>        in=0
>>       do, k=1,5
>>       do, l=1,5
>>        in=in+1
>>       matrix(k,l)=in
>>       enddo
>>       enddo
>>       m=5
>>       n=5
>>       do, i=1,m
>>       write(*,"(5i5)") ( matrix(i,j), j=1,n )
>>       enddo
>>       end
>>  
> 
> Excellent.  My kind of programming language!  See
> http://www.python.org/doc/humor/#bad-habits.
> 
> Anyway, that translates, more or less, as follows.
> 
> Note that I'm modeling the Fortran 2-dimensional array as a dictionary
> keyed by (k, l) tuples.  That's easy an convenient, but conceptually a
> poor fit and not terribly efficient.  If efficiency is an issue (i.e.
> much larger values of (k, l), you probably want to be looking at numpy.
> 
> Also, "in" is a keyword in python, so I changed that to "value".
> There's probably cleaner ways to do this. I did a pretty literal
> transliteration.
> 
> 
> matrix = {}
> value = 0
> for k in range(1, 6):
>    for l in range(1, 6):
>       value += 1
>       matrix[(k, l)] = value
> 
> for i in range(1, 6):
>    print ",".join("%5d" % matrix[(i, j)] for j in range(1, 6))
> 
> This prints:
> 
>     1,    2,    3,    4,    5
>     6,    7,    8,    9,   10
>    11,   12,   13,   14,   15
>    16,   17,   18,   19,   20
>    21,   22,   23,   24,   25

Or, as the OP may be on the road to numpy anyway:

>>> import numpy
>>> a = numpy.arange(1, 26).reshape(5, 5)
>>> a
array([[ 1,  2,  3,  4,  5],
       [ 6,  7,  8,  9, 10],
       [11, 12, 13, 14, 15],
       [16, 17, 18, 19, 20],
       [21, 22, 23, 24, 25]])
>>> import sys
>>> numpy.savetxt(sys.stdout, a, delimiter=", ", fmt="%5d")
    1,     2,     3,     4,     5
    6,     7,     8,     9,    10
   11,    12,    13,    14,    15
   16,    17,    18,    19,    20
   21,    22,    23,    24,    25




From bahamutzero8825 at gmail.com  Tue May  7 15:58:59 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 07 May 2013 14:58:59 -0500
Subject: Making safe file names
Message-ID: <51895D03.4000300@gmail.com>

Currently, I keep Last.fm artist data caches to avoid unnecessary API calls and have been naming the files using the artist name. However,
artist names can have characters that are not allowed in file names for most file systems (e.g., C/A/T has forward slashes). Are there any
recommended strategies for naming such files while avoiding conflicts (I wouldn't want to run into problems for an artist named C-A-T or
CAT, for example)? I'd like to make the files easily identifiable, and there really are no limits on what characters can be in an artist name.
-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From tjreedy at udel.edu  Tue May  7 18:01:34 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Tue, 07 May 2013 18:01:34 -0400
Subject: Making safe file names
In-Reply-To: <51895D03.4000300@gmail.com>
References: <51895D03.4000300@gmail.com>
Message-ID: <kmbtjn$cvc$1@ger.gmane.org>

On 5/7/2013 3:58 PM, Andrew Berg wrote:
> Currently, I keep Last.fm artist data caches to avoid unnecessary API calls and have been naming the files using the artist name. However,
> artist names can have characters that are not allowed in file names for most file systems (e.g., C/A/T has forward slashes). Are there any
> recommended strategies for naming such files while avoiding conflicts (I wouldn't want to run into problems for an artist named C-A-T or
> CAT, for example)? I'd like to make the files easily identifiable, and there really are no limits on what characters can be in an artist name.

Sounds like you want something like the html escape or urlencode 
functions, which serve the same purpose of encoding special chars. 
Rather than invent a new tranformation, you could use the same scheme 
used for html entities. (Sorry, I forget the details.) It is possible 
that one of the functions would work for you as is, or with little 
modification.

Terry





From bahamutzero8825 at gmail.com  Tue May  7 19:00:43 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 07 May 2013 18:00:43 -0500
Subject: Making safe file names
In-Reply-To: <kmbtjn$cvc$1@ger.gmane.org>
References: <51895D03.4000300@gmail.com> <kmbtjn$cvc$1@ger.gmane.org>
Message-ID: <5189879B.6060001@gmail.com>

On 2013.05.07 17:01, Terry Jan Reedy wrote:
> Sounds like you want something like the html escape or urlencode 
> functions, which serve the same purpose of encoding special chars. 
> Rather than invent a new tranformation, you could use the same scheme 
> used for html entities. (Sorry, I forget the details.) It is possible 
> that one of the functions would work for you as is, or with little 
> modification.
This has the problem of mangling non-ASCII characters (and artist names with non-ASCII characters are not rare). I most definitely want to
keep as many characters untouched as possible so that the files are easy to identify by looking at the file name. Ideally, only characters
that file systems don't like would be transformed.

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From fabiosantosart at gmail.com  Tue May  7 18:18:40 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 7 May 2013 23:18:40 +0100
Subject: Making safe file names
In-Reply-To: <51895D03.4000300@gmail.com>
References: <51895D03.4000300@gmail.com>
Message-ID: <CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>

I suggest Base64. b64encode
(http://docs.python.org/2/library/base64.html#base64.b64encode) and
b64decode take an argument which allows you to eliminate the pesky "/"
character. It's reversible and simple.

More suggestions: how about a hash? Or just use IDs from the database?

On Tue, May 7, 2013 at 8:58 PM, Andrew Berg <bahamutzero8825 at gmail.com> wrote:
> Currently, I keep Last.fm artist data caches to avoid unnecessary API calls and have been naming the files using the artist name. However,
> artist names can have characters that are not allowed in file names for most file systems (e.g., C/A/T has forward slashes). Are there any
> recommended strategies for naming such files while avoiding conflicts (I wouldn't want to run into problems for an artist named C-A-T or
> CAT, for example)? I'd like to make the files easily identifiable, and there really are no limits on what characters can be in an artist name.
> --
> CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1
> --
> http://mail.python.org/mailman/listinfo/python-list



--
F?bio Santos


From rosuav at gmail.com  Tue May  7 19:04:23 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 8 May 2013 09:04:23 +1000
Subject: Making safe file names
In-Reply-To: <CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
Message-ID: <CAPTjJmpmPVOQzGFQj9c-m=W-+oE+cyZ3qSC6HJnkSCBLZ=FXGg@mail.gmail.com>

On Wed, May 8, 2013 at 8:18 AM, F?bio Santos <fabiosantosart at gmail.com> wrote:
> I suggest Base64. b64encode
> (http://docs.python.org/2/library/base64.html#base64.b64encode) and
> b64decode take an argument which allows you to eliminate the pesky "/"
> character. It's reversible and simple.

But it doesn't look anything like the original.

I'd be inclined to go for something like quoted-printable or
URL-encoding; special characters become much longer, but ordinary
characters (mostly) stay as themselves.

ChrisA


From bahamutzero8825 at gmail.com  Tue May  7 19:10:25 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 07 May 2013 18:10:25 -0500
Subject: Making safe file names
In-Reply-To: <CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
Message-ID: <518989E1.8010701@gmail.com>

On 2013.05.07 17:18, F?bio Santos wrote:
> I suggest Base64. b64encode
> (http://docs.python.org/2/library/base64.html#base64.b64encode) and
> b64decode take an argument which allows you to eliminate the pesky "/"
> character. It's reversible and simple.
> 
> More suggestions: how about a hash? Or just use IDs from the database?
None of these would work because I would have no idea which file stores data for which artist without writing code to figure it out. If I
were to end up writing a bug that messed up a few of my cache files and noticed it with a specific artist (e.g., doing a "now playing" and
seeing the wrong tags), I would either have to manually match up the hash or base64 encoding in order to delete just that file so that it
gets regenerated or nuke and regenerate my entire cache.

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From roy at panix.com  Wed May  8 20:16:25 2013
From: roy at panix.com (Roy Smith)
Date: Wed, 08 May 2013 20:16:25 -0400
Subject: Making safe file names
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
Message-ID: <roy-1B572B.20162508052013@news.panix.com>

In article <mailman.1465.1368056269.3114.python-list at python.org>,
 Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:

> On Tue, 07 May 2013 18:10:25 -0500, Andrew Berg
> <bahamutzero8825 at gmail.com> declaimed the following in
> gmane.comp.python.general:
> 
> > None of these would work because I would have no idea which file stores 
> > data for which artist without writing code to figure it out. If I
> > were to end up writing a bug that messed up a few of my cache files and 
> > noticed it with a specific artist (e.g., doing a "now playing" and
> > seeing the wrong tags), I would either have to manually match up the hash 
> > or base64 encoding in order to delete just that file so that it
> > gets regenerated or nuke and regenerate my entire cache.
> >
> 	And now you've seen why music players don't show the user the
> physical file name, but maintain a database mapping the internal data
> (name, artist, track#, album, etc.) to whatever mangled name was needed
> to satisfy the file system.

Yup.  At Songza, we deal with this crap every day.  It usually bites us 
the worst when trying to do keyword searches.  When somebody types in 
"Blue Oyster Cult", they really mean "Blue Oyster Cult", and our search 
results need to reflect that.  Likewise for Ke$ha, Beyonce, and I don't 
even want to think about the artist formerly known as an unpronounceable 
glyph.

Pro-tip, guys.  If you want to form a band, and expect people to be able 
to find your stuff in a search engine some day, don't play cute with 
your name.


From rosuav at gmail.com  Wed May  8 20:27:14 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 9 May 2013 10:27:14 +1000
Subject: Making safe file names
In-Reply-To: <roy-1B572B.20162508052013@news.panix.com>
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
	<roy-1B572B.20162508052013@news.panix.com>
Message-ID: <CAPTjJmqSz7h+sOtu3=ryjMiNrGd2-JszRbBC0Rn8wA9p47r4CA@mail.gmail.com>

On Thu, May 9, 2013 at 10:16 AM, Roy Smith <roy at panix.com> wrote:
> Pro-tip, guys.  If you want to form a band, and expect people to be able
> to find your stuff in a search engine some day, don't play cute with
> your name.

It's the modern equivalent of names like Catherine Withekay.

ChrisA


From steve+comp.lang.python at pearwood.info  Wed May  8 21:49:22 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 01:49:22 GMT
Subject: Making safe file names
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
	<roy-1B572B.20162508052013@news.panix.com>
Message-ID: <518b00a2$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Wed, 08 May 2013 20:16:25 -0400, Roy Smith wrote:

> Yup.  At Songza, we deal with this crap every day.  It usually bites us
> the worst when trying to do keyword searches.  When somebody types in
> "Blue Oyster Cult", they really mean "Blue Oyster Cult", 

Surely they really mean Blue ?yster Cult.


> and our search
> results need to reflect that.  Likewise for Ke$ha, Beyonce, and I don't
> even want to think about the artist formerly known as an unpronounceable
> glyph.

Dropped or incorrect accents are no different from any other misspelling, 
and good search engines (whether online or in a desktop application) 
should be able to deal with a tolerable number of misspellings.

Googling for "Blue Oyster Cult" brings up four of the top ten hits 
spelled correctly with the accent, "Blue ?yster Cult". Even misspelled as 
"blew oytser cult", Google does the right thing.

Even Bing manages to find Ke$ha's wikipedia page, her official website, 
youtube channel, facebook and myspace pages from the misspelling "kehsha".



> Pro-tip, guys.  If you want to form a band, and expect people to be able
> to find your stuff in a search engine some day, don't play cute with
> your name.

Googling for "the the" (including quotes) brings up 145 million hits, 
nine of the first ten hits being relevant to the band. 

On the other hand, I wouldn't want to be in a band called "The Beetles".


-- 
Steven


From roy at panix.com  Wed May  8 21:56:41 2013
From: roy at panix.com (Roy Smith)
Date: Wed, 08 May 2013 21:56:41 -0400
Subject: Making safe file names
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
	<roy-1B572B.20162508052013@news.panix.com>
	<518b00a2$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-B50670.21564108052013@news.panix.com>

In article <518b00a2$0$29997$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> > When somebody types in
> > "Blue Oyster Cult", they really mean "Blue Oyster Cult", 
> 
> Surely they really mean Blue ??yster Cult.

Yes.  The oomlaut was there when I typed it.  Who knows what happened to 
it by the time it hit the wire.


From bahamutzero8825 at gmail.com  Wed May  8 22:11:28 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Wed, 08 May 2013 21:11:28 -0500
Subject: Making safe file names
In-Reply-To: <roy-1B572B.20162508052013@news.panix.com>
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
	<roy-1B572B.20162508052013@news.panix.com>
Message-ID: <518B05D0.7060206@gmail.com>

On 2013.05.08 19:16, Roy Smith wrote:
> Yup.  At Songza, we deal with this crap every day.  It usually bites us 
> the worst when trying to do keyword searches.  When somebody types in 
> "Blue Oyster Cult", they really mean "Blue Oyster Cult", and our search 
> results need to reflect that.  Likewise for Ke$ha, Beyonce, and I don't 
> even want to think about the artist formerly known as an unpronounceable 
> glyph.
>
> Pro-tip, guys.  If you want to form a band, and expect people to be able 
> to find your stuff in a search engine some day, don't play cute with 
> your name.
It's a thing (especially in witch house) to make names with odd glyphs in order to be harder to find and be more "underground". Very silly.
Try doing searches for these artists with names like these:
http://www.last.fm/music/%E2%96%BC%E2%96%A1%E2%96%A0%E2%96%A1%E2%96%A0%E2%96%A1%E2%96%A0
http://www.last.fm/music/ki%E2%80%A0%E2%80%A0y+c%E2%96%B2t
-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From steve+comp.lang.python at pearwood.info  Wed May  8 23:08:43 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 03:08:43 GMT
Subject: Making safe file names
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
	<roy-1B572B.20162508052013@news.panix.com>
	<mailman.1474.1368065495.3114.python-list@python.org>
Message-ID: <518b133b$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Wed, 08 May 2013 21:11:28 -0500, Andrew Berg wrote:

> It's a thing (especially in witch house) to make names with odd glyphs
> in order to be harder to find and be more "underground". Very silly. Try
> doing searches for these artists with names like these:

Challenge accepted.

> http://www.last.fm/music/%E2%96%BC%E2%96%A1%E2%96%A0%E2%96%A1%E2%96%A0%
E2%96%A1%E2%96%A0
> http://www.last.fm/music/ki%E2%80%A0%E2%80%A0y+c%E2%96%B2t


The second one is trivial. Googling for "kitty cat" "witch 
house" (including quotes) gives at least 3 relevant links out of the top 
4 hits are relevant. (I'm not sure about the Youtube page.) That gets you 
the correct spelling, "ki??y c?t", and googling for that brings up many 
more hits.

The first one is a tad trickier, since googling for "???????" brings up 
nothing at all, and "mourning star" doesn't give any relevant hits on the 
first page. But "mourning star" "witch house" (inc. quotes) is successful.

I suspect that the only way to be completely ungoogleable would be to 
name yourself something common, not something obscure. Say, if you called 
yourself "Hard Rock Band", and did hard rock. But then, googling for 
"Heavy Metal" alone brings up the magazine as the fourth hit, so if you 
get famous enough, even that won't work.



-- 
Steven


From rosuav at gmail.com  Wed May  8 23:53:27 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 9 May 2013 13:53:27 +1000
Subject: Making safe file names
In-Reply-To: <518b133b$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
	<roy-1B572B.20162508052013@news.panix.com>
	<mailman.1474.1368065495.3114.python-list@python.org>
	<518b133b$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmp0bP1UHRzMERizrg0pu+pZqkSaA6R9aT_dUj1WBZmaXA@mail.gmail.com>

On Thu, May 9, 2013 at 1:08 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> I suspect that the only way to be completely ungoogleable would be to
> name yourself something common, not something obscure. Say, if you called
> yourself "Hard Rock Band", and did hard rock. But then, googling for
> "Heavy Metal" alone brings up the magazine as the fourth hit, so if you
> get famous enough, even that won't work.

Yeah, so why are ubergeneric domain names worth so much? Whatevs.

The best way to be findable in a web search is to have content on your
web site. Real crawlable content. I guarantee you'll be found. Even if
you're some tiny thing tucked away in a corner of teh interwebs, you
can be found.

http://www.google.com/search?q=minstrel+hall

The song is there, but so is an obscure little D&D MUD.

ChrisA


From roy at panix.com  Thu May  9 08:55:35 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 09 May 2013 08:55:35 -0400
Subject: Making safe file names
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
	<roy-1B572B.20162508052013@news.panix.com>
	<mailman.1474.1368065495.3114.python-list@python.org>
	<518b133b$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-313758.08553509052013@news.panix.com>

In article <518b133b$0$29997$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> I suspect that the only way to be completely ungoogleable would be to 
> name yourself something common, not something obscure.

http://en.wikipedia.org/wiki/The_band


From greg.ewing at canterbury.ac.nz  Thu May  9 20:04:58 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Fri, 10 May 2013 12:04:58 +1200
Subject: Making safe file names
In-Reply-To: <roy-313758.08553509052013@news.panix.com>
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
	<roy-1B572B.20162508052013@news.panix.com>
	<mailman.1474.1368065495.3114.python-list@python.org>
	<518b133b$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-313758.08553509052013@news.panix.com>
Message-ID: <av2rtdF5igdU1@mid.individual.net>

Roy Smith wrote:
> In article <518b133b$0$29997$c3e8da3$5496439d at news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> 
>>I suspect that the only way to be completely ungoogleable would be to 
>>name yourself something common, not something obscure.
> 
> http://en.wikipedia.org/wiki/The_band

Nope... googling for "the band" brings that up as the
very first result.

The Google knows all. You cannot escape The Google...

-- 
Greg


From python.list at tim.thechases.com  Thu May  9 20:17:07 2013
From: python.list at tim.thechases.com (Tim Chase)
Date: Thu, 9 May 2013 19:17:07 -0500
Subject: Making safe file names
In-Reply-To: <av2rtdF5igdU1@mid.individual.net>
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<mailman.1465.1368056269.3114.python-list@python.org>
	<roy-1B572B.20162508052013@news.panix.com>
	<mailman.1474.1368065495.3114.python-list@python.org>
	<518b133b$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-313758.08553509052013@news.panix.com>
	<av2rtdF5igdU1@mid.individual.net>
Message-ID: <20130509191707.4047935d@bigbox.christie.dr>

On 2013-05-10 12:04, Gregory Ewing wrote:
> Roy Smith wrote:
> > http://en.wikipedia.org/wiki/The_band
> 
> Nope... googling for "the band" brings that up as the
> very first result.
> 
> The Google knows all. You cannot escape The Google...

That does it.  I'm naming my band "Google". :-)

-tkc




From bahamutzero8825 at gmail.com  Wed May  8 22:12:42 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Wed, 08 May 2013 21:12:42 -0500
Subject: Making safe file names
In-Reply-To: <v9olo8dnct9scscmpv4mlbd53ahkmuit43@invalid.netcom.com>
References: <51895D03.4000300@gmail.com>
	<CAA=1kxTnyFgLW=N_7mOCNnj75qDHt8Dfd-aYUYD8deLTrUBQ4g@mail.gmail.com>
	<518989E1.8010701@gmail.com>
	<v9olo8dnct9scscmpv4mlbd53ahkmuit43@invalid.netcom.com>
Message-ID: <518B061A.6000007@gmail.com>

On 2013.05.08 18:37, Dennis Lee Bieber wrote:
> 	And now you've seen why music players don't show the user the
> physical file name, but maintain a database mapping the internal data
> (name, artist, track#, album, etc.) to whatever mangled name was needed
> to satisfy the file system.
Tags are used mainly for organization but a nice benefit of tags is that they are not subject to file system or URL or whatever other
limits. If an audio file has no metadata, most players will show the file name.

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From python at mrabarnett.plus.com  Tue May  7 18:21:17 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 07 May 2013 23:21:17 +0100
Subject: Making safe file names
In-Reply-To: <51895D03.4000300@gmail.com>
References: <51895D03.4000300@gmail.com>
Message-ID: <51897E5D.4070401@mrabarnett.plus.com>

On 07/05/2013 20:58, Andrew Berg wrote:
> Currently, I keep Last.fm artist data caches to avoid unnecessary API calls and have been naming the files using the artist name. However,
> artist names can have characters that are not allowed in file names for most file systems (e.g., C/A/T has forward slashes). Are there any
> recommended strategies for naming such files while avoiding conflicts (I wouldn't want to run into problems for an artist named C-A-T or
> CAT, for example)? I'd like to make the files easily identifiable, and there really are no limits on what characters can be in an artist name.
>
Conflicts won't occur if:

1. All of the characters of the artist's name are mapped to an encoding.

2. Different characters map to different encodings.

3. No encoding is a prefix of another encoding.

In practice, you'll be mapping most characters to themselves.



From drsalists at gmail.com  Tue May  7 18:29:32 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Tue, 7 May 2013 15:29:32 -0700
Subject: Making safe file names
In-Reply-To: <51895D03.4000300@gmail.com>
References: <51895D03.4000300@gmail.com>
Message-ID: <CAGGBd_q-VDKAv5-019-UOY6pWpfTZDPj3VqhSR3QDvJSuM2T9Q@mail.gmail.com>

On 5/7/13, Andrew Berg <bahamutzero8825 at gmail.com> wrote:
> Currently, I keep Last.fm artist data caches to avoid unnecessary API calls
> and have been naming the files using the artist name. However,
> artist names can have characters that are not allowed in file names for most
> file systems (e.g., C/A/T has forward slashes). Are there any
> recommended strategies for naming such files while avoiding conflicts (I
> wouldn't want to run into problems for an artist named C-A-T or
> CAT, for example)? I'd like to make the files easily identifiable, and there
> really are no limits on what characters can be in an artist name.

You might consider:
http://stromberg.dnsalias.org/svn/backshift/trunk/escape_mod.py
http://stromberg.dnsalias.org/svn/backshift/trunk/test-escape_mod

It doubles the length of the string, but it produces safe, easily
readable escaped strings - which tends to make debugging easier.

It requires a couple of other modules (easily obtained from the same
SVN repo) though.


From jt at toerring.de  Tue May  7 18:37:01 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 7 May 2013 22:37:01 GMT
Subject: Making safe file names
References: <mailman.1418.1367956750.3114.python-list@python.org>
Message-ID: <aute0dFt9itU1@mid.uni-berlin.de>

Andrew Berg <bahamutzero8825 at gmail.com> wrote:
> Currently, I keep Last.fm artist data caches to avoid unnecessary API calls
> and have been naming the files using the artist name. However, artist names
> can have characters that are not allowed in file names for most file systems
> (e.g., C/A/T has forward slashes). Are there any recommended strategies for
> naming such files while avoiding conflicts (I wouldn't want to run into
> problems for an artist named C-A-T or CAT, for example)? I'd like to make
> the files easily identifiable, and there really are no limits on what
> characters can be in an artist name. --

It's not clear what the context that you need this for. You
could e.g. replace all characters not allowed by the file
system by their hexidecimal (ASCII) values, preceeded by a
'%" (so '/' would be changed to '%2F', and also encode a '%'
itself in a name by '%25'). Then you have a well-defined
two-way mapping ("isomorphic" if I remember my math-lear-
nining days correctly) between the original name and the
way you store it. E.g.

  "C/A/T"  would become  "C%2FA%2FT"

and

  "C%2FA/T"  would become  "C%252FA%2FT"

You can translate back and forth between them with not too
much effort.

Of course, that assumes that '%' is a character allowed by
your file system - otherwise pick some other one, any one
will do in principle. It's a bit harder for a human to in-
terpret but rathe likely not that much of a problem. You
probably will have seen that kind of scheme used in URLs.
The concept is rather old and called 'escape character',
i.e. have one character that assumes some special meaning
and also "escaped" it.

If, on the hand, those names are never to be translated back
to the original name another strategy would be to use the SHA1
hash value of the artists name. Since clashes between SHA1 hash
values are rather hard to produce it's a rather safe method of
converting something (i.e. the artists name) to a number. The
drawback, of course, is that you can't translate back from the
hash value to the original name (if that would be simple the
whole thing wouldn't work;-)

                       Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From bahamutzero8825 at gmail.com  Tue May  7 19:30:53 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 07 May 2013 18:30:53 -0500
Subject: Making safe file names
In-Reply-To: <aute0dFt9itU1@mid.uni-berlin.de>
References: <mailman.1418.1367956750.3114.python-list@python.org>
	<aute0dFt9itU1@mid.uni-berlin.de>
Message-ID: <51898EAD.1070401@gmail.com>

On 2013.05.07 17:37, Jens Thoms Toerring wrote:
> You
> could e.g. replace all characters not allowed by the file
> system by their hexidecimal (ASCII) values, preceeded by a
> '%" (so '/' would be changed to '%2F', and also encode a '%'
> itself in a name by '%25'). Then you have a well-defined
> two-way mapping ("isomorphic" if I remember my math-lear-
> nining days correctly) between the original name and the
> way you store it. E.g.
> 
>   "C/A/T"  would become  "C%2FA%2FT"
> 
> and
> 
>   "C%2FA/T"  would become  "C%252FA%2FT"
> 
> You can translate back and forth between them with not too
> much effort.
> 
> Of course, that assumes that '%' is a character allowed by
> your file system - otherwise pick some other one, any one
> will do in principle. It's a bit harder for a human to in-
> terpret but rathe likely not that much of a problem.
Yes, something like this is what I am trying to achieve. Judging by the responses I've gotten so far, I think I'll have to roll my own
transformation scheme since URL encoding and the like transform Unicode characters. I can memorize that ???? is a Japanese composer who
is well-known for his works in the Final Fantasy series of video games. Trying to match up the URL-encoded version to an artist would be
almost impossible when I have several other artist names that have no ASCII characters.

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From davea at davea.name  Tue May  7 20:14:54 2013
From: davea at davea.name (Dave Angel)
Date: Tue, 07 May 2013 20:14:54 -0400
Subject: Making safe file names
In-Reply-To: <51895D03.4000300@gmail.com>
References: <51895D03.4000300@gmail.com>
Message-ID: <518998FE.6030805@davea.name>

On 05/07/2013 03:58 PM, Andrew Berg wrote:
> Currently, I keep Last.fm artist data caches to avoid unnecessary API calls and have been naming the files using the artist name. However,
> artist names can have characters that are not allowed in file names for most file systems (e.g., C/A/T has forward slashes). Are there any
> recommended strategies for naming such files while avoiding conflicts (I wouldn't want to run into problems for an artist named C-A-T or
> CAT, for example)? I'd like to make the files easily identifiable, and there really are no limits on what characters can be in an artist name.
>

So what you need first is a list of allowable characters for all your 
target OS versions.  And don't forget that the allowable characters may 
vary depending on the particular file system(s) mounted on a given OS.

You also need to decide how to handle Unicode characters, since they're 
different for different OS.  In Windows on NTFS, filenames are in 
Unicode, while on Unix, filenames are bytes.  So on one of those, you 
will be encoding/decoding if your code is to be mostly portable.

Don't forget that ls and rm may not use the same encoding you're using. 
  So you may not consider it adequate to make the names legal, but you 
may also want they easily typeable in the shell.

-- 
DaveA


From bahamutzero8825 at gmail.com  Tue May  7 20:51:24 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 07 May 2013 19:51:24 -0500
Subject: Making safe file names
In-Reply-To: <518998FE.6030805@davea.name>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
Message-ID: <5189A18C.5060109@gmail.com>

On 2013.05.07 19:14, Dave Angel wrote:
> You also need to decide how to handle Unicode characters, since they're 
> different for different OS.  In Windows on NTFS, filenames are in 
> Unicode, while on Unix, filenames are bytes.  So on one of those, you 
> will be encoding/decoding if your code is to be mostly portable.
Characters outside whatever sys.getfilesystemencoding() returns won't be allowed. If the user's locale settings don't support Unicode, my
program will be far from the only one to have issues with it. Any problem reports that arise from a user moving between legacy encodings
will generally be ignored. I haven't yet decided how I will handle artist names with characters outside UTF-8, but inside UTF-16/32 (UTF-16
is just fine on Windows/NTFS, but on Unix(-ish) systems, many use UTF-8 in their locale settings).
> Don't forget that ls and rm may not use the same encoding you're using. 
> So you may not consider it adequate to make the names legal, but you 
> may also want they easily typeable in the shell.
I don't understand. I have no intention of changing Unicode characters.


This is not a Unicode issue since (modern) file systems will happily accept it. The issue is that certain characters (which are ASCII) are
not allowed on some file systems:
 \ / : * ? " < > | @ and the NUL character
The first 9 are not allowed on NTFS, the @ is not allowed on ext3cow, and NUL and / are not allowed on pretty much any file system. Locale
settings and encodings aside, these 11 characters will need to be escaped.
-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From davea at davea.name  Tue May  7 21:13:11 2013
From: davea at davea.name (Dave Angel)
Date: Tue, 07 May 2013 21:13:11 -0400
Subject: Making safe file names
In-Reply-To: <5189A18C.5060109@gmail.com>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<5189A18C.5060109@gmail.com>
Message-ID: <5189A6A7.4040104@davea.name>

On 05/07/2013 08:51 PM, Andrew Berg wrote:
> On 2013.05.07 19:14, Dave Angel wrote:
>> You also need to decide how to handle Unicode characters, since they're
>> different for different OS.  In Windows on NTFS, filenames are in
>> Unicode, while on Unix, filenames are bytes.  So on one of those, you
>> will be encoding/decoding if your code is to be mostly portable.
> Characters outside whatever sys.getfilesystemencoding() returns won't be allowed. If the user's locale settings don't support Unicode, my
> program will be far from the only one to have issues with it. Any problem reports that arise from a user moving between legacy encodings
> will generally be ignored. I haven't yet decided how I will handle artist names with characters outside UTF-8,

There aren't any characters "outside UTF-8".  But a character is not "in 
utf-8", it can be encoded by utf-8.

  but inside UTF-16/32 (UTF-16

Nor outside UTF-16 or 32.

> is just fine on Windows/NTFS, but on Unix(-ish) systems, many use UTF-8 in their locale settings).
>> Don't forget that ls and rm may not use the same encoding you're using.
>> So you may not consider it adequate to make the names legal, but you
>> may also want they easily typeable in the shell.
> I don't understand. I have no intention of changing Unicode characters.

So you're comfortable typing arbitrary characters?  what about all the 
characters that have identical displays in your font? What about viewing 
0x07 in the terminal window?  Or 0x04?

>
>
> This is not a Unicode issue since (modern) file systems will happily accept it. The issue is that certain characters (which are ASCII) are
> not allowed on some file systems:
>   \ / : * ? " < > | @ and the NUL character
> The first 9 are not allowed on NTFS, the @ is not allowed on ext3cow, and NUL and / are not allowed on pretty much any file system. Locale
> settings and encodings aside, these 11 characters will need to be escaped.
>

As soon as you have a small, finite list of invalid characters, writing 
an escape system is pretty easy.


-- 
DaveA


From bahamutzero8825 at gmail.com  Tue May  7 22:21:41 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 07 May 2013 21:21:41 -0500
Subject: Making safe file names
In-Reply-To: <5189A6A7.4040104@davea.name>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<5189A18C.5060109@gmail.com> <5189A6A7.4040104@davea.name>
Message-ID: <5189B6B5.9020600@gmail.com>

On 2013.05.07 20:13, Dave Angel wrote:
> So you're comfortable typing arbitrary characters?  what about all the 
> characters that have identical displays in your font?
Identification is more important than typing. I can copy and paste into a terminal if necessary. I don't foresee typing out one of the
filenames being anything more than a rare occurrence, but I will occasionally just read the list.
> What about viewing 
> 0x07 in the terminal window?  Or 0x04?
I don't think Last.fm will even send those characters. In any case, control characters in artist names are rare enough that it's not worth
the trouble to write the code to avoid the problems associated with them.
> As soon as you have a small, finite list of invalid characters, writing 
> an escape system is pretty easy.
Probably. I was just hoping there was an existing system that would work, but as I said in a different reply, it would seem I need to roll
my own.

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From nhodgson at iinet.net.au  Tue May  7 21:28:11 2013
From: nhodgson at iinet.net.au (Neil Hodgson)
Date: Wed, 08 May 2013 11:28:11 +1000
Subject: Making safe file names
In-Reply-To: <mailman.1430.1367974288.3114.python-list@python.org>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
Message-ID: <Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>

Andrew Berg:

> This is not a Unicode issue since (modern) file systems will happily accept it. The issue is that certain characters (which are ASCII) are
> not allowed on some file systems:
>   \ / : * ? "<  >  | @ and the NUL character
> The first 9 are not allowed on NTFS, the @ is not allowed on ext3cow, and NUL and / are not allowed on pretty much any file system. Locale
> settings and encodings aside, these 11 characters will need to be escaped.

    There's also the Windows device name hole. There may be trouble with 
artists named 'COM4', 'CLOCK$', 'Con', or similar.

http://support.microsoft.com/kb/74496
http://en.wikipedia.org/wiki/Nul_%28band%29

    Neil


From davea at davea.name  Tue May  7 21:45:08 2013
From: davea at davea.name (Dave Angel)
Date: Tue, 07 May 2013 21:45:08 -0400
Subject: Making safe file names
In-Reply-To: <Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
Message-ID: <5189AE24.7060002@davea.name>

On 05/07/2013 09:28 PM, Neil Hodgson wrote:
> Andrew Berg:
>
>> This is not a Unicode issue since (modern) file systems will happily
>> accept it. The issue is that certain characters (which are ASCII) are
>> not allowed on some file systems:
>>   \ / : * ? "<  >  | @ and the NUL character
>> The first 9 are not allowed on NTFS, the @ is not allowed on ext3cow,
>> and NUL and / are not allowed on pretty much any file system. Locale
>> settings and encodings aside, these 11 characters will need to be
>> escaped.
>
>     There's also the Windows device name hole. There may be trouble with
> artists named 'COM4', 'CLOCK$', 'Con', or similar.
>

In MSDOS 2, there was a switch that would tell the OS to ignore such 
names unless they were prefixed by \DEV.  But like the switchar switch, 
it was largely ignored by the ignorant, and probably doesn't exist in 
current versions of M$OS

> http://support.microsoft.com/kb/74496
> http://en.wikipedia.org/wiki/Nul_%28band%29
>
>     Neil

While we're looking for trouble, there's also case insensitivity. 
Unclear if the user cares, but tom and TOM are the same file in most 
configurations of NT.

-- 
DaveA


From bahamutzero8825 at gmail.com  Tue May  7 22:20:13 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 07 May 2013 21:20:13 -0500
Subject: Making safe file names
In-Reply-To: <5189AE24.7060002@davea.name>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
	<5189AE24.7060002@davea.name>
Message-ID: <5189B65D.6010103@gmail.com>

On 2013.05.07 20:45, Dave Angel wrote:
> While we're looking for trouble, there's also case insensitivity. 
> Unclear if the user cares, but tom and TOM are the same file in most 
> configurations of NT.
Artist names on Last.fm cannot differ only in case. This does remind me to make sure to update the case of the artist name as necessary,
though. For example, if Sam becomes SAM again (I have seen Last.fm change the case for artist names), I need to make sure that I don't end
up with two file names differing only in case.

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From bahamutzero8825 at gmail.com  Tue May  7 22:06:27 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 07 May 2013 21:06:27 -0500
Subject: Making safe file names
In-Reply-To: <Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
Message-ID: <5189B323.20700@gmail.com>

On 2013.05.07 20:28, Neil Hodgson wrote:
> http://support.microsoft.com/kb/74496
> http://en.wikipedia.org/wiki/Nul_%28band%29
I can indeed confirm that at least 'nul' cannot be used as a filename. However, I add an extension to the file names to identify them as caches.

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From davea at davea.name  Wed May  8 00:10:13 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 08 May 2013 00:10:13 -0400
Subject: Making safe file names
In-Reply-To: <5189B323.20700@gmail.com>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
	<5189B323.20700@gmail.com>
Message-ID: <5189D025.3020204@davea.name>

On 05/07/2013 10:06 PM, Andrew Berg wrote:
> On 2013.05.07 20:28, Neil Hodgson wrote:
>> http://support.microsoft.com/kb/74496
>> http://en.wikipedia.org/wiki/Nul_%28band%29
> I can indeed confirm that at least 'nul' cannot be used as a filename. However, I add an extension to the file names to identify them as caches.
>

Won't help.  NUL.txt is just as reserved as NUL is.  Extensions are 
ignored in this particular piece of historical nonsense.


-- 
DaveA


From roy at panix.com  Tue May  7 22:21:53 2013
From: roy at panix.com (Roy Smith)
Date: Tue, 07 May 2013 22:21:53 -0400
Subject: Making safe file names
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
	<mailman.1435.1367977523.3114.python-list@python.org>
Message-ID: <roy-9FFDA1.22215307052013@news.panix.com>

In article <mailman.1435.1367977523.3114.python-list at python.org>,
 Dave Angel <davea at davea.name> wrote:

> While we're looking for trouble, there's also case insensitivity. 
> Unclear if the user cares, but tom and TOM are the same file in most 
> configurations of NT.

OSX, too.


From albert at spenarnc.xs4all.nl  Tue May 28 09:44:10 2013
From: albert at spenarnc.xs4all.nl (Albert van der Horst)
Date: 28 May 2013 13:44:10 GMT
Subject: Making safe file names
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
Message-ID: <51a4b4aa$0$6063$e4fe514c@dreader36.news.xs4all.nl>

In article <Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d at westnet.com.au>,
Neil Hodgson  <nhodgson at iinet.net.au> wrote:
>Andrew Berg:
>
>> This is not a Unicode issue since (modern) file systems will happily
>accept it. The issue is that certain characters (which are ASCII) are
>> not allowed on some file systems:
>>   \ / : * ? "<  >  | @ and the NUL character
>> The first 9 are not allowed on NTFS, the @ is not allowed on ext3cow,
>and NUL and / are not allowed on pretty much any file system. Locale
>> settings and encodings aside, these 11 characters will need to be escaped.
>
>    There's also the Windows device name hole. There may be trouble with
>artists named 'COM4', 'CLOCK$', 'Con', or similar.
>
>http://support.microsoft.com/kb/74496

That applies to MS-DOS names. God forbid that this still holds on more modern
Microsoft operating systems?

>http://en.wikipedia.org/wiki/Nul_%28band%29
>
>    Neil
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst



From rosuav at gmail.com  Tue May 28 09:53:03 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 28 May 2013 23:53:03 +1000
Subject: Making safe file names
In-Reply-To: <51a4b4aa$0$6063$e4fe514c@dreader36.news.xs4all.nl>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
	<51a4b4aa$0$6063$e4fe514c@dreader36.news.xs4all.nl>
Message-ID: <CAPTjJmpqHcgXzSm26bVPoJRzMm2Jk55c79AhLoFbJdpjxbi_Dw@mail.gmail.com>

On Tue, May 28, 2013 at 11:44 PM, Albert van der Horst
<albert at spenarnc.xs4all.nl> wrote:
> In article <Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d at westnet.com.au>,
> Neil Hodgson  <nhodgson at iinet.net.au> wrote:
>>    There's also the Windows device name hole. There may be trouble with
>>artists named 'COM4', 'CLOCK$', 'Con', or similar.
>>
>>http://support.microsoft.com/kb/74496
>
> That applies to MS-DOS names. God forbid that this still holds on more modern
> Microsoft operating systems?

Python 3.3.0 (v3.3.0:bd8afb90ebf2, Sep 29 2012, 10:55:48) [MSC v.1600 32 bit (In
tel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> open("com1","w").write("Test\n")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
FileNotFoundError: [Errno 2] No such file or directory: 'com1'
>>> open("con","w").write("Test\n")
Test
5
>>>

ChrisA


From invalid at invalid.invalid  Tue May 28 12:03:16 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 16:03:16 +0000 (UTC)
Subject: Making safe file names
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<Lvydneajg7LXNhTMnZ2dnUVZ_rKdnZ2d@westnet.com.au>
	<51a4b4aa$0$6063$e4fe514c@dreader36.news.xs4all.nl>
Message-ID: <ko2kg3$9oh$4@reader1.panix.com>

On 2013-05-28, Albert van der Horst <albert at spenarnc.xs4all.nl> wrote:

>> There's also the Windows device name hole. There may be trouble with
>> artists named 'COM4', 'CLOCK$', 'Con', or similar.
>>
>>http://support.microsoft.com/kb/74496
>
> That applies to MS-DOS names. God forbid that this still holds on
> more modern Microsoft operating systems?

There are no more modern Microsoft operating systems.  Only more
recent ones.  There are still lots of reserved filenames in recent
versions of Windows.

-- 
Grant Edwards               grant.b.edwards        Yow! I've got an IDEA!!
                                  at               Why don't I STARE at you
                              gmail.com            so HARD, you forget your
                                                   SOCIAL SECURITY NUMBER!!


From steve+comp.lang.python at pearwood.info  Tue May  7 23:40:50 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 08 May 2013 03:40:50 GMT
Subject: Making safe file names
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
Message-ID: <5189c941$0$11094$c3e8da3@news.astraweb.com>

On Tue, 07 May 2013 19:51:24 -0500, Andrew Berg wrote:

> On 2013.05.07 19:14, Dave Angel wrote:
>> You also need to decide how to handle Unicode characters, since they're
>> different for different OS.  In Windows on NTFS, filenames are in
>> Unicode, while on Unix, filenames are bytes.  So on one of those, you
>> will be encoding/decoding if your code is to be mostly portable.
>
> Characters outside whatever sys.getfilesystemencoding() returns won't be
> allowed. If the user's locale settings don't support Unicode, my program
> will be far from the only one to have issues with it. Any problem
> reports that arise from a user moving between legacy encodings will
> generally be ignored. I haven't yet decided how I will handle artist
> names with characters outside UTF-8, but inside UTF-16/32 (UTF-16 is
> just fine on Windows/NTFS, but on Unix(-ish) systems, many use UTF-8 in
> their locale settings).

There aren't any characters outside of UTF-8 :-) UTF-8 covers the entire 
Unicode range, unlike other encodings like Latin-1 or ASCII.

Well, that is to say, there may be characters that are not (yet) handled 
at all by Unicode, but there are no known legacy encodings that support 
such characters.

To a first approximation, Unicode covers the entire set of characters in 
human use, and for those which it does not, there is always the private 
use area. So for example, if you wish to record the Artist Formerly Known 
As "The Artist Formerly Known As Prince" as Love Symbol, you could pick 
an arbitrary private use code point, declare that for your application 
that code point means Love Symbol, and use that code point as the artist 
name. You could even come up with a custom font that includes a rendition 
of that character glyph.

However, there are byte combinations which are not valid UTF-8, which is 
a different story. If you're receiving bytes from (say) a file name, they 
may not necessarily make up a valid UTF-8 string. But this is not an 
issue if you are receiving data from something guaranteed to be valid 
UTF-8.


>> Don't forget that ls and rm may not use the same encoding you're using.
>> So you may not consider it adequate to make the names legal, but you
>> may also want they easily typeable in the shell.
>
> I don't understand. I have no intention of changing Unicode characters.

Of course you do. You even talk below about Unicode characters like * 
and ? not being allowed on NTFS systems.

Perhaps you are thinking that there are a bunch of characters over here 
called "plain text ASCII characters", and a *different* bunch of 
characters with funny accents and stuff called "Unicode characters". If 
so, then you are labouring under a misapprehension, and you should start 
off by reading this:

http://www.joelonsoftware.com/articles/Unicode.html


then come back with any questions.


> This is not a Unicode issue since (modern) file systems will happily
> accept it. The issue is that certain characters (which are ASCII) are
> not allowed on some file systems:
>  \ / : * ? " < > | @ and the NUL character

These are all Unicode characters too. Unicode is a subset of ASCII, so 
anything which is ASCII is also Unicode.


> The first 9 are not allowed on NTFS, the @ is not allowed on ext3cow,
> and NUL and / are not allowed on pretty much any file system. Locale
> settings and encodings aside, these 11 characters will need to be
> escaped.

If you have an artist with control characters in their name, like newline 
or carriage return or NUL, I think it is fair to just drop the control 
characters and then give the artist a thorough thrashing with a halibut.

Does your mapping really need to be guaranteed reversible? If you have an 
artist called "JoeBlow", and another artist called "Joe\0Blow", and a 
third called "Joe\nBlow", does it *really* matter if your application 
conflates them?


-- 
Steven


From davea at davea.name  Wed May  8 00:13:20 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 08 May 2013 00:13:20 -0400
Subject: Making safe file names
In-Reply-To: <5189c941$0$11094$c3e8da3@news.astraweb.com>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<5189c941$0$11094$c3e8da3@news.astraweb.com>
Message-ID: <5189D0E0.3080007@davea.name>

On 05/07/2013 11:40 PM, Steven D'Aprano wrote:
>
>    <SNIP>
>
> These are all Unicode characters too. Unicode is a subset of ASCII, so
> anything which is ASCII is also Unicode.
>
>

Typo.  You meant  Unicode is a superset of ASCII.


-- 
DaveA


From steve+comp.lang.python at pearwood.info  Wed May  8 00:47:24 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 08 May 2013 04:47:24 GMT
Subject: Making safe file names
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<5189c941$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1441.1367986414.3114.python-list@python.org>
Message-ID: <5189d8dc$0$11094$c3e8da3@news.astraweb.com>

On Wed, 08 May 2013 00:13:20 -0400, Dave Angel wrote:

> On 05/07/2013 11:40 PM, Steven D'Aprano wrote:
>>
>>    <SNIP>
>>
>> These are all Unicode characters too. Unicode is a subset of ASCII, so
>> anything which is ASCII is also Unicode.
>>
>>
>>
> Typo.  You meant  Unicode is a superset of ASCII.

Damn. Yes, you're right. I was thinking superset, but my fingers typed 
subset.

Thanks for the correction.


-- 
Steven


From bahamutzero8825 at gmail.com  Wed May  8 00:49:46 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 07 May 2013 23:49:46 -0500
Subject: Making safe file names
In-Reply-To: <5189c941$0$11094$c3e8da3@news.astraweb.com>
References: <51895D03.4000300@gmail.com> <518998FE.6030805@davea.name>
	<mailman.1430.1367974288.3114.python-list@python.org>
	<5189c941$0$11094$c3e8da3@news.astraweb.com>
Message-ID: <5189D96A.8050209@gmail.com>

On 2013.05.07 22:40, Steven D'Aprano wrote:
> There aren't any characters outside of UTF-8 :-) UTF-8 covers the entire 
> Unicode range, unlike other encodings like Latin-1 or ASCII.
You are correct. I'm not sure what I was thinking.

>> I don't understand. I have no intention of changing Unicode characters.
> 
> Of course you do. You even talk below about Unicode characters like * 
> and ? not being allowed on NTFS systems.
I worded that incorrectly. What I meant, of course, is that I intend to preserve as many characters as possible and have no need to stay
within ASCII.

> If you have an artist with control characters in their name, like newline 
> or carriage return or NUL, I think it is fair to just drop the control 
> characters and then give the artist a thorough thrashing with a halibut.
While the thrashing with a halibut may be warranted (though I personally would use a rubber chicken), conflicts are problematic.

> Does your mapping really need to be guaranteed reversible? If you have an 
> artist called "JoeBlow", and another artist called "Joe\0Blow", and a 
> third called "Joe\nBlow", does it *really* matter if your application 
> conflates them?
Yes and yes. Some artists like to be real cute with their names and make witch house artist names look tame in comparison, and some may
choose to use names similar to some very popular artists. I've also seen people scrobble fake artists with names that look like real artist
names (using things like a non-breaking space instead of a regular space) with different artist pictures in order to confuse and troll
people. If I could remember the user profiles with this, I'd link them. Last.fm is a silly place.
As I said before though, I don't think control characters are even allowed in artist names (likely for technical reasons).
-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From roy at panix.com  Tue May  7 20:22:17 2013
From: roy at panix.com (Roy Smith)
Date: Tue, 07 May 2013 20:22:17 -0400
Subject: Making safe file names
References: <51895D03.4000300@gmail.com>
	<mailman.1428.1367972114.3114.python-list@python.org>
Message-ID: <roy-EE293A.20221707052013@news.panix.com>

In article <mailman.1428.1367972114.3114.python-list at python.org>,
 Dave Angel <davea at davea.name> wrote:

> On 05/07/2013 03:58 PM, Andrew Berg wrote:
> > Currently, I keep Last.fm artist data caches to avoid unnecessary API calls 
> > and have been naming the files using the artist name. However,
> > artist names can have characters that are not allowed in file names for 
> > most file systems (e.g., C/A/T has forward slashes). Are there any
> > recommended strategies for naming such files while avoiding conflicts (I 
> > wouldn't want to run into problems for an artist named C-A-T or
> > CAT, for example)? I'd like to make the files easily identifiable, and 
> > there really are no limits on what characters can be in an artist name.
> >
> 
> So what you need first is a list of allowable characters for all your 
> target OS versions.  And don't forget that the allowable characters may 
> vary depending on the particular file system(s) mounted on a given OS.
> 
> You also need to decide how to handle Unicode characters, since they're 
> different for different OS.  In Windows on NTFS, filenames are in 
> Unicode, while on Unix, filenames are bytes.  So on one of those, you 
> will be encoding/decoding if your code is to be mostly portable.
> 
> Don't forget that ls and rm may not use the same encoding you're using. 
>   So you may not consider it adequate to make the names legal, but you 
> may also want they easily typeable in the shell.

One possible tool that may help you here is unidecode 
(https://pypi.python.org/pypi/Unidecode).  It doesn't solve your whole 
problem, but it does help get unicode text into a form which is both 
7-bit clean and human readable.


From cheirasacan at gmail.com  Tue May  7 16:27:59 2013
From: cheirasacan at gmail.com (cheirasacan at gmail.com)
Date: Tue, 7 May 2013 13:27:59 -0700 (PDT)
Subject: Get filename using filefialog.askfilename
Message-ID: <ab1feb45-0397-4411-bab1-898c95f57b05@googlegroups.com>

Well. It's driving me crazy. So simple....

I use:

file = filedialog.askopenfile ( mode....... )

to open a file with an open dialog box, OK. Made it.

How i get the name of the opened file?

i do :

print(file)

the output is: <......name="file.doc"...mode=......encoding..........  >

How can i get the second member of 'file'?

I had prove with print(file[1]) and print(file(1)) but does not work.

And i am unable to find a detailed reference to this object in the i.net

http://fossies.org/dox/Python-3.3.1/filedialog_8py_source.html#l00393 is
where i could reach!



Thanks



From gordon at panix.com  Tue May  7 16:37:26 2013
From: gordon at panix.com (John Gordon)
Date: Tue, 7 May 2013 20:37:26 +0000 (UTC)
Subject: Get filename using filefialog.askfilename
References: <ab1feb45-0397-4411-bab1-898c95f57b05@googlegroups.com>
Message-ID: <kmbom6$itp$1@reader1.panix.com>

In <ab1feb45-0397-4411-bab1-898c95f57b05 at googlegroups.com> cheirasacan at gmail.com writes:

> print(file)

> the output is: <......name="file.doc"...mode=......encoding..........  >

> How can i get the second member of 'file'?

If you're using the interpreter, you can type this command:

    >>> help(file)

And it will display documentation for using objects of that type.
You can also use this command:

    >>> dir(file)

And it will display all the members and methods that the object provides.

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From tjreedy at udel.edu  Tue May  7 17:53:32 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Tue, 07 May 2013 17:53:32 -0400
Subject: Get filename using filefialog.askfilename
In-Reply-To: <ab1feb45-0397-4411-bab1-898c95f57b05@googlegroups.com>
References: <ab1feb45-0397-4411-bab1-898c95f57b05@googlegroups.com>
Message-ID: <kmbt4l$8o3$1@ger.gmane.org>

On 5/7/2013 4:27 PM, cheirasacan at gmail.com wrote:

> file = filedialog.askopenfile ( mode....... )

askopenfile is a convenience function that creates an Open dialog 
object, shows it, gets the name returned by the dialog, opens the file 
with that name, and returns an appropriate normal file object

> to open a file with an open dialog box, OK. Made it.
>
> How i get the name of the opened file?

file.name, (at least in 3.3), which in your example below is "file.doc"

> print(file)
>
> the output is: <......name="file.doc"...mode=......encoding..........  >

This is the standard string representation of a file object. It is 
created from the various attributes of the file instance, including 
file.name.

> How can i get the second member of 'file'?

Strings do not have fields. The second 'member', would be the second 
character, file[1], which is not what you want.

> And i am unable to find a detailed reference to this object in the i.net

Use the Fine Manual. The entry for builtin open() function, which you 
should read to understand the 'open' part of askopenfile, directs you to 
the Glossary entry 'file object' which says "There are actually three 
categories of file objects: raw binary files, buffered binary files and 
text files. Their interfaces are defined in the io module. The canonical 
way to create a file object is by using the open() function." The kind 
of file object you get is determined by the mode ('b' present or not), 
buffer arg, and maybe something else. You can look in the io chapter or 
use dir() and help() as John G. suggested.

Python programmers should really learn to use dir(), help(), and the 
manuls, including the index and module index.

--
Terry Jan Reedy




From cheirasacan at gmail.com  Wed May  8 16:14:42 2013
From: cheirasacan at gmail.com (cheirasacan at gmail.com)
Date: Wed, 8 May 2013 13:14:42 -0700 (PDT)
Subject: Get filename using filefialog.askfilename
In-Reply-To: <mailman.1419.1367963622.3114.python-list@python.org>
References: <ab1feb45-0397-4411-bab1-898c95f57b05@googlegroups.com>
	<mailman.1419.1367963622.3114.python-list@python.org>
Message-ID: <f41664f6-9f02-473c-bcd9-5f88980aab63@googlegroups.com>

El martes, 7 de mayo de 2013 23:53:32 UTC+2, Terry Jan Reedy  escribi?:
> On 5/7/2013 4:27 PM, cheirasacan at gmail.com wrote:
> 
> 
> 
> > file = filedialog.askopenfile ( mode....... )
> 
> 
> 
> askopenfile is a convenience function that creates an Open dialog 
> 
> object, shows it, gets the name returned by the dialog, opens the file 
> 
> with that name, and returns an appropriate normal file object
> 
> 
> 
> > to open a file with an open dialog box, OK. Made it.
> 
> >
> 
> > How i get the name of the opened file?
> 
> 
> 
> file.name, (at least in 3.3), which in your example below is "file.doc"
> 
> 
> 
> > print(file)
> 
> >
> 
> > the output is: <......name="file.doc"...mode=......encoding..........  >
> 
> 
> 
> This is the standard string representation of a file object. It is 
> 
> created from the various attributes of the file instance, including 
> 
> file.name.
> 
> 
> 
> > How can i get the second member of 'file'?
> 
> 
> 
> Strings do not have fields. The second 'member', would be the second 
> 
> character, file[1], which is not what you want.
> 
> 
> 
> > And i am unable to find a detailed reference to this object in the i.net
> 
> 
> 
> Use the Fine Manual. The entry for builtin open() function, which you 
> 
> should read to understand the 'open' part of askopenfile, directs you to 
> 
> the Glossary entry 'file object' which says "There are actually three 
> 
> categories of file objects: raw binary files, buffered binary files and 
> 
> text files. Their interfaces are defined in the io module. The canonical 
> 
> way to create a file object is by using the open() function." The kind 
> 
> of file object you get is determined by the mode ('b' present or not), 
> 
> buffer arg, and maybe something else. You can look in the io chapter or 
> 
> use dir() and help() as John G. suggested.
> 
> 
> 
> Python programmers should really learn to use dir(), help(), and the 
> 
> manuls, including the index and module index.
> 
> 
> 
> --
> 
> Terry Jan Reedy

Yeah. This is an answer. A lot of thanks.


From davea at davea.name  Wed May  8 18:52:48 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 08 May 2013 18:52:48 -0400
Subject: Get filename using filefialog.askfilename
In-Reply-To: <f41664f6-9f02-473c-bcd9-5f88980aab63@googlegroups.com>
References: <ab1feb45-0397-4411-bab1-898c95f57b05@googlegroups.com>
	<mailman.1419.1367963622.3114.python-list@python.org>
	<f41664f6-9f02-473c-bcd9-5f88980aab63@googlegroups.com>
Message-ID: <518AD740.9070207@davea.name>

On 05/08/2013 04:14 PM, cheirasacan at gmail.com wrote:
> El martes, 7 de mayo de 2013 23:53:32 UTC+2, Terry Jan Reedy  escribi?:
>> On 5/7/2013 4:27 PM, cheirasacan at gmail.com wrote:
>>
>>
>>     <SNIP - a double-spaced google-groups copy of lots of useful advice>
>>>
>
> Yeah. This is an answer. A lot of thanks.
>

For a moment there, I thought you were being sarcastic, and ungrateful 
at that.  But I figured that it must have been my imagination.

Usually, it's better to teach a man to fish, rather than just handing 
him one.  But some would rather just have an answer, but not the 
understanding of how to acquire it.

So, some unsolicited advice.  And mixed in, maybe the actual answer to 
your original question.

1) Lose googlegroups, or figure a way to avoid its bad habits.  Your 
responses here are doublespaced, which makes it hard to read, especially 
when you include so much that has nothing to do with your response. 
Also, triple posting leads to a number of problems, not the least of 
which is the number of other responders who killfile anything from 
googlegroups.  See http://wiki.python.org/moin/GoogleGroupsPython.

2) Include enough of your code that people can actually figure out what 
you're up to.  You're asking a question about a method of an object 
filedialog, but you never show how it's created.

3) Include enough of your error messages or diagnostic prints that we 
can see what's going on.

 > output is: <......name="file.doc"...mode=......encoding..........  >

You elided the only important part of that line, the type of the object 
you're asking about.  Most of us would know that a file object has an 
attribute of name.  But instead I spent quite a while trying to find 
what GUI library you were using that might be handing back something 
representing a file.

4) include the environment you're running in.  In your first thread, you 
included a line:
    Using Windows 7, Python 3.3, sfml 1.3.0 library, ...

Very helpful.  But no such hints here.

5) try not to override builtin names with your own local variables.  In 
this case, you defined a local variable called file, which overwrites, 
presumably by coincidence, its own type name.


Thanks for pointing out the "annotated source code" on fossies.org.  I 
wasn't aware of that location.





-- 
DaveA


From sokovic.anamarija at gmail.com  Tue May  7 18:26:47 2013
From: sokovic.anamarija at gmail.com (sokovic.anamarija at gmail.com)
Date: Tue, 7 May 2013 15:26:47 -0700 (PDT)
Subject: multiple versions of python
Message-ID: <72f93710-9812-441e-8d3d-f221d5698f69@googlegroups.com>

Hi,

what is the generally recommended structure when we have into play this type of problem:
multiple versions of python (both in the sense of main versions and sub versions, e.g., 
2.7 :
   2.7.1
   2.7.3
3:
 3.3
   3.3.1
Different versions of gcc
different compilation strategies (-vanilla and non-vanilla)
different modules (numpy,scipy) together with the different versions of all the rest.

any help is appreciated

Ana


From roy at panix.com  Tue May  7 19:59:52 2013
From: roy at panix.com (Roy Smith)
Date: Tue, 07 May 2013 19:59:52 -0400
Subject: multiple versions of python
References: <72f93710-9812-441e-8d3d-f221d5698f69@googlegroups.com>
Message-ID: <roy-C81859.19595207052013@news.panix.com>

In article <72f93710-9812-441e-8d3d-f221d5698f69 at googlegroups.com>,
 sokovic.anamarija at gmail.com wrote:

> Hi,
> 
> what is the generally recommended structure when we have into play this type 
> of problem:
> multiple versions of python (both in the sense of main versions and sub 
> versions, e.g., 
> 2.7 :
>    2.7.1
>    2.7.3
> 3:
>  3.3
>    3.3.1
> Different versions of gcc
> different compilation strategies (-vanilla and non-vanilla)
> different modules (numpy,scipy) together with the different versions of all 
> the rest.
> 
> any help is appreciated
> 
> Ana

Virtualenv is your friend.


From fabiosantosart at gmail.com  Wed May  8 03:07:25 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Wed, 8 May 2013 08:07:25 +0100
Subject: multiple versions of python
In-Reply-To: <roy-C81859.19595207052013@news.panix.com>
References: <72f93710-9812-441e-8d3d-f221d5698f69@googlegroups.com>
	<roy-C81859.19595207052013@news.panix.com>
Message-ID: <CAA=1kxRfNQkEcWBv1h_W=P2KGuyWO54r4sogg2Kp4qmiLz+1Kw@mail.gmail.com>

On 8 May 2013 01:03, "Roy Smith" <roy at panix.com> wrote:
>
> In article <72f93710-9812-441e-8d3d-f221d5698f69 at googlegroups.com>,
>  sokovic.anamarija at gmail.com wrote:
>
> > Hi,
> >
> > what is the generally recommended structure when we have into play this
type
> > of problem:
> > multiple versions of python (both in the sense of main versions and sub
> > versions, e.g.,
> > 2.7 :
> >    2.7.1
> >    2.7.3
> > 3:
> >  3.3
> >    3.3.1
> > Different versions of gcc
> > different compilation strategies (-vanilla and non-vanilla)
> > different modules (numpy,scipy) together with the different versions of
all
> > the rest.
> >
> > any help is appreciated
> >
> > Ana
>
> Virtualenv is your friend.
> --
> http://mail.python.org/mailman/listinfo/python-list

Have you looked at tox? It manages a folder full of virtualenvs for you,
including your dependencies, and allows you to run your tests against every
version.
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From cjw at ncf.ca  Tue May  7 21:35:50 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Tue, 07 May 2013 21:35:50 -0400
Subject: multiple versions of python
In-Reply-To: <72f93710-9812-441e-8d3d-f221d5698f69@googlegroups.com>
References: <72f93710-9812-441e-8d3d-f221d5698f69@googlegroups.com>
Message-ID: <kmca64$pd3$1@theodyn.ncf.ca>

On 07/05/2013 6:26 PM, sokovic.anamarija at gmail.com wrote:
> Hi,
>
> what is the generally recommended structure when we have into play this type of problem:
> multiple versions of python (both in the sense of main versions and sub versions, e.g.,
> 2.7 :
>     2.7.1
>     2.7.3
> 3:
>   3.3
>     3.3.1
> Different versions of gcc
> different compilation strategies (-vanilla and non-vanilla)
> different modules (numpy,scipy) together with the different versions of all the rest.
>
> any help is appreciated
>
> Ana
>
Do you really need more than 2.7.3  and 3.3.1.

Typically, these go to C:\Python27 and C:\Python33 with windows.

Colin W.


From roy at panix.com  Tue May  7 21:38:36 2013
From: roy at panix.com (Roy Smith)
Date: Tue, 07 May 2013 21:38:36 -0400
Subject: multiple versions of python
References: <72f93710-9812-441e-8d3d-f221d5698f69@googlegroups.com>
	<kmca64$pd3$1@theodyn.ncf.ca>
Message-ID: <roy-D26967.21383607052013@news.panix.com>

In article <kmca64$pd3$1 at theodyn.ncf.ca>,
 "Colin J. Williams" <cjw at ncf.ca> wrote:

> Do you really need more than 2.7.3  and 3.3.1.

It's often useful to have older versions around, so you can test your 
code against them.  Lots of projects try to stay compatible with older 
releases.


From breamoreboy at yahoo.co.uk  Tue May  7 22:25:24 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 08 May 2013 03:25:24 +0100
Subject: multiple versions of python
In-Reply-To: <kmca64$pd3$1@theodyn.ncf.ca>
References: <72f93710-9812-441e-8d3d-f221d5698f69@googlegroups.com>
	<kmca64$pd3$1@theodyn.ncf.ca>
Message-ID: <kmcd2j$q55$1@ger.gmane.org>

On 08/05/2013 02:35, Colin J. Williams wrote:
> On 07/05/2013 6:26 PM, sokovic.anamarija at gmail.com wrote:
>> Hi,
>>
>> what is the generally recommended structure when we have into play
>> this type of problem:
>> multiple versions of python (both in the sense of main versions and
>> sub versions, e.g.,
>> 2.7 :
>>     2.7.1
>>     2.7.3
>> 3:
>>   3.3
>>     3.3.1
>> Different versions of gcc
>> different compilation strategies (-vanilla and non-vanilla)
>> different modules (numpy,scipy) together with the different versions
>> of all the rest.
>>
>> any help is appreciated
>>
>> Ana
>>
> Do you really need more than 2.7.3  and 3.3.1.
>
> Typically, these go to C:\Python27 and C:\Python33 with windows.
>
> Colin W.

In which case you'll normally be doing a binary installation.  If you're 
compiling it's more likely to be VC++ not gcc.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Wed May  8 04:52:12 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 08 May 2013 08:52:12 GMT
Subject: object.enable() anti-pattern
Message-ID: <518a123c$0$11094$c3e8da3@news.astraweb.com>

I'm looking for some help in finding a term, it's not Python-specific but 
does apply to some Python code.

This is an anti-pattern to avoid. The idea is that creating a resource 
ought to be the same as "turning it on", or enabling it, or similar. For 
example, we don't do this in Python:


f = file("some_file.txt")
f.open()
data = f.read()


because reading the file can fail if you forget to call open first. 
Instead, Python uses a factory function that creates the file object and 
opens it:

f = open("some_file.txt")  # if this succeeds, f is ready to use
data = f.read()


Basically, any time you have two steps required for using an object, e.g. 
like this:

obj = someobject(arg1, arg2)
obj.enable()

you should move the make-it-work functionality out of the enable method 
and into __init__ so that creating the object creates it in a state ready 
to work.

I read a blog some time ago (a year ago?) that discusses this anti-
pattern, and I'm pretty sure gave it a specific name, but I cannot find 
it again. Can anyone find any references to this anti-pattern? My google-
fu is letting me down.



(For what it's worth, I'm refactoring some of my own code that falls into 
this anti-pattern. Die, enable method, die die die!)


-- 
Steven


From christian at python.org  Wed May  8 05:51:47 2013
From: christian at python.org (Christian Heimes)
Date: Wed, 08 May 2013 11:51:47 +0200
Subject: object.enable() anti-pattern
In-Reply-To: <518a123c$0$11094$c3e8da3@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
Message-ID: <kmd77e$793$1@ger.gmane.org>

Am 08.05.2013 10:52, schrieb Steven D'Aprano:
> Basically, any time you have two steps required for using an object, e.g. 
> like this:
> 
> obj = someobject(arg1, arg2)
> obj.enable()
> 
> you should move the make-it-work functionality out of the enable method 
> and into __init__ so that creating the object creates it in a state ready 
> to work.

In general I agree that an object.enable() function is ugly. ;)

But it's not necessarily the best solution for all problems. If the
resource needs some kind of cleanup, the context api (__enter__() /
__exit__()) is perfectly fine way to enable and disable the object.

For example:

class MyFile:
    def __init__(self, filename):
        self.filename = filename
    def __enter__(self):
        self.open()
        return self
    def __exit__(self, exc_type, exc_val, exc_tb):
        self.close()

I suggest that you mention the context API in your blog post, too.

Christian



From robert.kern at gmail.com  Wed May  8 06:13:33 2013
From: robert.kern at gmail.com (Robert Kern)
Date: Wed, 08 May 2013 11:13:33 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <518a123c$0$11094$c3e8da3@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
Message-ID: <kmd8g8$i3t$1@ger.gmane.org>

On 2013-05-08 09:52, Steven D'Aprano wrote:
> I'm looking for some help in finding a term, it's not Python-specific but
> does apply to some Python code.
>
> This is an anti-pattern to avoid. The idea is that creating a resource
> ought to be the same as "turning it on", or enabling it, or similar.

I don't think the anti-pattern has a name, but it's opposite pattern is named:

http://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco



From steve+comp.lang.python at pearwood.info  Wed May  8 08:30:30 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 08 May 2013 12:30:30 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1448.1368008024.3114.python-list@python.org>
Message-ID: <518a4566$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Wed, 08 May 2013 11:13:33 +0100, Robert Kern wrote:

> On 2013-05-08 09:52, Steven D'Aprano wrote:
>> I'm looking for some help in finding a term, it's not Python-specific
>> but does apply to some Python code.
>>
>> This is an anti-pattern to avoid. The idea is that creating a resource
>> ought to be the same as "turning it on", or enabling it, or similar.
> 
> I don't think the anti-pattern has a name, but it's opposite pattern is
> named:
> 
> http://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization

That sounds like it should be related, but it actually isn't since RAII 
actually has little to do with *acquiring* the resource and everything to 
do with *releasing* it. See, for example:

http://stackoverflow.com/questions/2321511/what-is-meant-by-resource-
acquisition-is-initialization-raii

where it is pointed out that the resource may be acquired outside of the 
object constructor and passed in as an argument. RAII is actually about 
deterministic destruction of objects and the release of their resources.

But thanks for the attempt :-)


-- 
Steven


From roy at panix.com  Wed May  8 09:17:17 2013
From: roy at panix.com (Roy Smith)
Date: Wed, 08 May 2013 09:17:17 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
Message-ID: <roy-B0966A.09171708052013@news.panix.com>

In article <518a123c$0$11094$c3e8da3 at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> I'm looking for some help in finding a term, it's not Python-specific but 
> does apply to some Python code.
> 
> This is an anti-pattern to avoid. The idea is that creating a resource 
> ought to be the same as "turning it on", or enabling it, or similar. For 
> example, we don't do this in Python:
> 
> 
> f = file("some_file.txt")
> f.open()
> data = f.read()

I've worked with C++ code that did this.  At one point in the evolution 
of OOP group consciousness, there was a feeling that constructors must 
never fail.  I don't remember if it was a general language-agnostic 
pattern, or a specific C++ reaction to poor exception handling code in 
early compilers.  What came out of that was the pattern you describe.  
All the code that could fail was factored out of the constructor into an 
"enable" method.

That being said, sometimes there are good reasons for doing this.  One 
example might be something like:

frobnicator = Frobnicator()
for file in my_file_list:
   frobnicator.munch(file)
   for line in frobnicator:
      process(line)

If creating a Frobnicator instance is very expensive, it might pay to 
create an instance once and keep reusing it on multiple files.  Here, 
munch() is your enable() method.  But, that's not quite what you were 
talking about.


From duncan.booth at invalid.invalid  Wed May  8 10:27:53 2013
From: duncan.booth at invalid.invalid (Duncan Booth)
Date: 8 May 2013 14:27:53 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
Message-ID: <XnsA1BA9D45BE58Cduncanbooth@127.0.0.1>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> I'm looking for some help in finding a term, it's not Python-specific
> but does apply to some Python code.
> 
> This is an anti-pattern to avoid. The idea is that creating a resource
> ought to be the same as "turning it on", or enabling it, or similar

I've come across this under the name 'two-phase construction', but as a 
desirable(!?) pattern rathern than as an anti-pattern.

In particular Symbian used it throughout as originally their C++ 
implementation didn't support exceptions. Instead they had a separate 
cleanup stack and objects that require cleanup were pushed onto that stack 
after being fully constructed but before calling the initialisation that 
required cleanup. See 
http://www.developer.nokia.com/Community/Wiki/Two-phase_construction


-- 
Duncan Booth


From dan at tombstonezero.net  Wed May  8 22:38:36 2013
From: dan at tombstonezero.net (Dan Sommers)
Date: Thu, 09 May 2013 02:38:36 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<XnsA1BA9D45BE58Cduncanbooth@127.0.0.1>
Message-ID: <M_Dit.288$oB7.229@newsfe02.iad>

On Wed, 08 May 2013 14:27:53 +0000, Duncan Booth wrote:

> Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

>> I'm looking for some help in finding a term, it's not Python-specific
>> but does apply to some Python code.
>> 
>> This is an anti-pattern to avoid. The idea is that creating a
>> resource ought to be the same as "turning it on", or enabling it, or
>> similar
> 
> I've come across this under the name 'two-phase construction', but as
> a desirable(!?) pattern rathern than as an anti-pattern.

Think of spinning off a thread:  initialize it synchronously, and then
let it execute asynchronously.  We tend towards that pattern even when
we know that execution will be synchronous, because we also that it
could be asynchronous one day.  Yes, we could wrap that up in a neat
bundle, but explicit is better than implicit.

Dan


From steve+comp.lang.python at pearwood.info  Thu May  9 01:37:35 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 05:37:35 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<XnsA1BA9D45BE58Cduncanbooth@127.0.0.1>
	<M_Dit.288$oB7.229@newsfe02.iad>
Message-ID: <518b361f$0$11120$c3e8da3@news.astraweb.com>

On Thu, 09 May 2013 02:38:36 +0000, Dan Sommers wrote:

> Think of spinning off a thread:  initialize it synchronously, and then
> let it execute asynchronously.  We tend towards that pattern even when
> we know that execution will be synchronous, because we also that it
> could be asynchronous one day.

Whether it is synchronous or asynchronous is irrelevant.

I can see use-cases for separating "make it go" from initialisation. It 
all depends on what you might want to do to the object before making it 
go. If the answer is "Nothing", then there is no reason not to have the 
constructor make it go. If the answer is, "Well, sometimes we need to do 
things to the object before making it go", then it makes sense to 
separate the two:

blob = MyBlob(arg1, arg2, agr3)
blob.poke("with a stick")
blob.append(data)
blob.foo = "spam"
blob.make_it_go()


I'm not talking about this case. I'm talking about the case where there's 
nothing you can do with the blob before making it go.


> Yes, we could wrap that up in a neat
> bundle, but explicit is better than implicit.

"And that is why we always write code like this:

n = int(int(len(something)) + int(1))

just to be sure that the result is explicitly an int and not just 
implicitly an int. Suppose some Javascript programmer was reading the 
code, and they thought that 1 was a floating point value. That would be 
bad!"


-- 
Steven


From rosuav at gmail.com  Thu May  9 01:52:02 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 9 May 2013 15:52:02 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <518b361f$0$11120$c3e8da3@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<XnsA1BA9D45BE58Cduncanbooth@127.0.0.1>
	<M_Dit.288$oB7.229@newsfe02.iad>
	<518b361f$0$11120$c3e8da3@news.astraweb.com>
Message-ID: <CAPTjJmpA2Df4CdhyzRSuAvrN63C+L5rn16g756WW4UwTj+Zw8Q@mail.gmail.com>

On Thu, May 9, 2013 at 3:37 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> I can see use-cases for separating "make it go" from initialisation. It
> all depends on what you might want to do to the object before making it
> go. If the answer is "Nothing", then there is no reason not to have the
> constructor make it go. If the answer is, "Well, sometimes we need to do
> things to the object before making it go", then it makes sense to
> separate the two:
>
> blob = MyBlob(arg1, arg2, agr3)
> blob.poke("with a stick")
> blob.append(data)
> blob.foo = "spam"
> blob.make_it_go()

Example use-case: Most GUI frameworks. You create a window, then
populate it, then show it. When you create the window object in
Python, you expect an actual window to exist, it should have its
handle etc. So it's still the same thing; the object is fully created
in its constructor.

ChrisA


From steve+comp.lang.python at pearwood.info  Wed May  8 23:12:09 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 03:12:09 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<XnsA1BA9D45BE58Cduncanbooth@127.0.0.1>
Message-ID: <518b1409$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Wed, 08 May 2013 14:27:53 +0000, Duncan Booth wrote:

> Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> 
>> I'm looking for some help in finding a term, it's not Python-specific
>> but does apply to some Python code.
>> 
>> This is an anti-pattern to avoid. The idea is that creating a resource
>> ought to be the same as "turning it on", or enabling it, or similar
> 
> I've come across this under the name 'two-phase construction', but as a
> desirable(!?) pattern rathern than as an anti-pattern.
> 
> In particular Symbian used it throughout as originally their C++
> implementation didn't support exceptions. Instead they had a separate
> cleanup stack and objects that require cleanup were pushed onto that
> stack after being fully constructed but before calling the
> initialisation that required cleanup. See
> http://www.developer.nokia.com/Community/Wiki/Two-phase_construction



Thanks for the link. It's obviously not the blog post I was looking for, 
but it is interesting.



-- 
Steven


From dan at tombstonezero.net  Wed May  8 22:42:01 2013
From: dan at tombstonezero.net (Dan Sommers)
Date: Thu, 09 May 2013 02:42:01 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
Message-ID: <Z1Eit.289$oB7.283@newsfe02.iad>

On Wed, 08 May 2013 08:52:12 +0000, Steven D'Aprano wrote:

> This is an anti-pattern to avoid. The idea is that creating a resource 
> ought to be the same as "turning it on", or enabling it, or similar. For 
> example, we don't do this in Python:
> 
> f = file("some_file.txt")
> f.open()
> data = f.read()

So why don't we do this?

    data = read("some_file.txt")

> because reading the file can fail if you forget to call open first. 
> Instead, Python uses a factory function that creates the file object and 
> opens it:
> 
> f = open("some_file.txt")  # if this succeeds, f is ready to use
> data = f.read()

That's just the "enable" paradigm in a socially acceptable and
traditional wrapper.

Opening and closing the file is an implementation detail, often defeated
by caching (application level or OS level) anyway.

Dan


From steve+comp.lang.python at pearwood.info  Thu May  9 01:23:59 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 05:23:59 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
Message-ID: <518b32ef$0$11120$c3e8da3@news.astraweb.com>

On Thu, 09 May 2013 02:42:01 +0000, Dan Sommers wrote:

> On Wed, 08 May 2013 08:52:12 +0000, Steven D'Aprano wrote:
> 
>> This is an anti-pattern to avoid. The idea is that creating a resource
>> ought to be the same as "turning it on", or enabling it, or similar.
>> For example, we don't do this in Python:
>> 
>> f = file("some_file.txt")
>> f.open()
>> data = f.read()
> 
> So why don't we do this?
> 
>     data = read("some_file.txt")

Because there is a lot more that you might want to do to a file than just 
read from it.

py> f = open('/tmp/x')
py> dir(f)
['_CHUNK_SIZE', '__class__', '__delattr__', '__dict__', '__dir__', 
'__doc__', '__enter__', '__eq__', '__exit__', '__format__', '__ge__', 
'__getattribute__', '__getstate__', '__gt__', '__hash__', '__init__', 
'__iter__', '__le__', '__lt__', '__ne__', '__new__', '__next__', 
'__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', 
'__str__', '__subclasshook__', '_checkClosed', '_checkReadable', 
'_checkSeekable', '_checkWritable', 'buffer', 'close', 'closed', 
'detach', 'encoding', 'errors', 'fileno', 'flush', 'isatty', 
'line_buffering', 'mode', 'name', 'newlines', 'read', 'readable', 
'readline', 'readlines', 'seek', 'seekable', 'tell', 'truncate', 
'writable', 'write', 'writelines']


That's 24 public methods and attributes, excluding private and dunder 
attributes.

There is no sensible use-case for creating a file without opening it. 
What would be the point? Any subsequent calls to just about any method 
will fail. Since you have to open the file after creating the file object 
anyway, why make them two different calls?

Besides, this is not to denigrate the idea of a read() function that 
takes a filename and returns its contents. But that is not an object 
constructor. It may construct a file object internally, but it doesn't 
return the file object, so it is completely unrelated to the scenario I 
described.



>> because reading the file can fail if you forget to call open first.
>> Instead, Python uses a factory function that creates the file object
>> and opens it:
>> 
>> f = open("some_file.txt")  # if this succeeds, f is ready to use 
>> data = f.read()
> 
> That's just the "enable" paradigm in a socially acceptable and
> traditional wrapper.

Well duh. That's like saying that for loops, while loops and co-routines 
are just GOTO in a socially acceptable and traditional wrapper. Of course 
they are. That's the whole point.



-- 
Steven


From tjreedy at udel.edu  Thu May  9 02:41:56 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Thu, 09 May 2013 02:41:56 -0400
Subject: object.enable() anti-pattern
In-Reply-To: <518b32ef$0$11120$c3e8da3@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
Message-ID: <kmfgfb$aqe$1@ger.gmane.org>

On 5/9/2013 1:23 AM, Steven D'Aprano wrote:

> Besides, this is not to denigrate the idea of a read() function that
> takes a filename and returns its contents. But that is not an object
> constructor. It may construct a file object internally, but it doesn't
> return the file object, so it is completely unrelated to the scenario I
> described.

At least a few stdlib modules that define classes *also* have such 
functions. They create an instance of the class, call one or more 
methods, and return the result of the method, discarding the instance. 
For instance, see the subprocess module, its POpen class, and module 
functions; or the timeit module, its Timer class, and functions.




From greg.ewing at canterbury.ac.nz  Thu May  9 03:54:56 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Thu, 09 May 2013 19:54:56 +1200
Subject: object.enable() anti-pattern
In-Reply-To: <518b32ef$0$11120$c3e8da3@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
Message-ID: <av132gFneo2U1@mid.individual.net>

Steven D'Aprano wrote:
> There is no sensible use-case for creating a file without opening it. 
> What would be the point?

Early unix systems often used this as a form of locking.

-- 
Greg


From cs at zip.com.au  Thu May  9 04:23:31 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Thu, 9 May 2013 18:23:31 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <av132gFneo2U1@mid.individual.net>
References: <av132gFneo2U1@mid.individual.net>
Message-ID: <20130509082331.GA46022@cskk.homeip.net>

On 09May2013 19:54, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
| Steven D'Aprano wrote:
| >There is no sensible use-case for creating a file without opening
| >it. What would be the point?
| 
| Early unix systems often used this as a form of locking.

Not just early systems: it's a nice lightweight method of making a
lockfile even today if you expect to work over NFS, where not that
many things are synchronous. You open a file with "0" modes, so
that it is _immediately_ not writable. Other attempts to make the
lock file thus fail because of the lack of write, even over NFS.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

You can listen to what everybody says, but the fact remains that you've got
to get out there and do the thing yourself.     - Joan Sutherland


From greg.ewing at canterbury.ac.nz  Thu May  9 18:56:45 2013
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Fri, 10 May 2013 10:56:45 +1200
Subject: object.enable() anti-pattern
In-Reply-To: <20130509082331.GA46022@cskk.homeip.net>
References: <av132gFneo2U1@mid.individual.net>
	<20130509082331.GA46022@cskk.homeip.net>
Message-ID: <518C29AD.7070302@canterbury.ac.nz>

Cameron Simpson wrote:
> You open a file with "0" modes, so
> that it is _immediately_ not writable. Other attempts to make the
> lock file thus fail because of the lack of write,

I don't think that's quite right. You open it with
O_CREAT+O_EXCL, which atomically fails if the file
already exists. The read/write modes don't really
come into it, as far as I know.

-- 
Greg


From cs at zip.com.au  Thu May  9 19:29:33 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Fri, 10 May 2013 09:29:33 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <518C29AD.7070302@canterbury.ac.nz>
References: <518C29AD.7070302@canterbury.ac.nz>
Message-ID: <20130509232933.GA94065@cskk.homeip.net>

On 10May2013 10:56, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
| Cameron Simpson wrote:
| >You open a file with "0" modes, so
| >that it is _immediately_ not writable. Other attempts to make the
| >lock file thus fail because of the lack of write,
| 
| I don't think that's quite right. You open it with
| O_CREAT+O_EXCL, which atomically fails if the file
| already exists. The read/write modes don't really
| come into it, as far as I know.

Interesting. That is more direct. My understanding that it was
enough to create the file with 0 modes. Maybe either will do. Must
check...

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Piracy gets easier every day, but listening to legally purchased music gets harder by the day.
Firehed - http://politics.slashdot.org/comments.pl?sid=179175&cid=14846089


From steve+comp.lang.python at pearwood.info  Thu May  9 07:30:32 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 11:30:32 GMT
Subject: object.enable() anti-pattern
References: <av132gFneo2U1@mid.individual.net>
	<mailman.1488.1368087823.3114.python-list@python.org>
Message-ID: <518b88d8$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Thu, 09 May 2013 18:23:31 +1000, Cameron Simpson wrote:

> On 09May2013 19:54, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> | Steven D'Aprano wrote:
> | > There is no sensible use-case for creating a file WITHOUT OPENING
> | > it. What would be the point?
> |
> | Early unix systems often used this as a form of locking.
> 
> Not just early systems: it's a nice lightweight method of making a
> lockfile even today if you expect to work over NFS, where not that many
> things are synchronous. You OPEN A FILE with "0" modes

[emphasis added]

This is all very well and good, but for the life of me, I cannot see how 
opening a file is a good example of not opening a file. Perhaps it is a 
Zen thing, like the sound no spoon makes when you don't tap it against a 
glass that isn't there.


-- 
Steven


From cs at zip.com.au  Thu May  9 19:36:43 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Fri, 10 May 2013 09:36:43 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <518b88d8$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <518b88d8$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20130509233643.GA95502@cskk.homeip.net>

On 09May2013 11:30, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
| On Thu, 09 May 2013 18:23:31 +1000, Cameron Simpson wrote:
| 
| > On 09May2013 19:54, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
| > | Steven D'Aprano wrote:
| > | > There is no sensible use-case for creating a file WITHOUT OPENING
| > | > it. What would be the point?
| > |
| > | Early unix systems often used this as a form of locking.
| > 
| > Not just early systems: it's a nice lightweight method of making a
| > lockfile even today if you expect to work over NFS, where not that many
| > things are synchronous. You OPEN A FILE with "0" modes
| 
| [emphasis added]
| This is all very well and good, but for the life of me, I cannot see how 
| opening a file is a good example of not opening a file. Perhaps it is a 
| Zen thing, like the sound no spoon makes when you don't tap it against a 
| glass that isn't there.

Because a file usually does not exist in isolation (yes sometimes
we want an isolated file). Files usually exist in the filesystem,
which is a namespace. And this is effectively a namespace operation,
not a data storage operation.

Of course, I can take this the other way: just because I opened it
with a 0 mode field doesn't mean _I_, the opener, cannot read/write
it. I've got an open file handle... A race free way to make a scratch
file in a shared area, for example.

The point is probably that a file isn't merely a feature free byte
storage container; in the real world they usually come with all
sorts of features like names and permissions. Those features will
always imply creative uses.

Anyway, this has little to do with your antipattern (about which
I'm not totally convinced anyway unless it is a rule of thumb or
code smell). It might apply to a Platonicly ideal file, but real
files have more than one use case.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

I just kept it wide-open thinking it would correct itself.
Then I ran out of talent.       - C. Fittipaldi


From steve+comp.lang.python at pearwood.info  Fri May 10 01:00:53 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 10 May 2013 05:00:53 GMT
Subject: object.enable() anti-pattern
References: <518b88d8$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1512.1368142627.3114.python-list@python.org>
Message-ID: <518c7f05$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 10 May 2013 09:36:43 +1000, Cameron Simpson wrote:

> On 09May2013 11:30, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote: 
> | On Thu, 09 May 2013 18:23:31 +1000, Cameron Simpson wrote: 
> |
> | > On 09May2013 19:54, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> | > | Steven D'Aprano wrote:
> | > | > There is no sensible use-case for creating a file WITHOUT
> | > | > OPENING it. What would be the point?
> | > |
> | > | Early unix systems often used this as a form of locking. 
> | >
> | > Not just early systems: it's a nice lightweight method of making a
> | > lockfile even today if you expect to work over NFS, where not that
> | > many things are synchronous. You OPEN A FILE with "0" modes 
> | [emphasis added]
>
> | This is all very well and good, but for the life of me, I cannot see
> | how opening a file is a good example of not opening a file. Perhaps it
> | is a Zen thing, like the sound no spoon makes when you don't tap it
> | against a glass that isn't there.
> 
> Because a file usually does not exist in isolation (yes sometimes we
> want an isolated file). Files usually exist in the filesystem, which is
> a namespace. And this is effectively a namespace operation, not a data
> storage operation.
>
> Of course, I can take this the other way: just because I opened it with
> a 0 mode field doesn't mean _I_, the opener, cannot read/write it. I've
> got an open file handle... A race free way to make a scratch file in a
> shared area, for example.


But you are opening the file. Therefore, it cannot possibly be an example 
of not opening the file.

Unlike Pascal, there is no way to create a C file descriptor in a closed 
state. Such a thing does not exist. If you have a file descriptor, the 
file is open. Once you close it, the file descriptor is no longer valid.

But even if C allowed you to do so, doesn't mean that it is a good idea. 
At least some variants of Pascal force you to do the following:

# Pseudo-code.
f = open(filename)
really_open(f)
data = read(f)  # or write, or *any other operation at all*

Surely we can agree that having to call both open() and really_open() 
before you get an actually opened file that you can use is one call too 
many? There is *nothing* you can do with f before calling really_open(). 
So why require it?

(For the record, "really_open" is spelled "reset" or "rewrite" depending 
on whether you want to read or write to the file.)


> The point is probably that a file isn't merely a feature free byte
> storage container; in the real world they usually come with all sorts of
> features like names and permissions. Those features will always imply
> creative uses.

There are at least three related but separate things here.

* file objects, or their low-level equivalent, file descriptors;

* pathnames;

* files on disk, which are an abstraction for data in a particular kind 
of data structure.

They are obviously related, but they are also obviously independent. You 
can have a pathname that doesn't refer to any file on disk; you can have 
a file on disk that has been lost, and therefore is no longer accessible 
via a file name. (If you run fsck or equivalent, the file may be 
recoverable, but the name will be lost.) You can open a file object, then 
unlink it so it no longer points to a file on disk, but does still accept 
read or write calls.

The counter-examples given so far apply to pathnames or files on disk. 
They don't apply to file objects and file descriptors. I have tried 
really hard to be clear that I am talking about file objects. To the 
extent that I have failed, I am sorry.


-- 
Steven


From roy at panix.com  Fri May 10 01:50:09 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 10 May 2013 01:50:09 -0400
Subject: object.enable() anti-pattern
References: <518b88d8$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1512.1368142627.3114.python-list@python.org>
	<518c7f05$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-7584FC.01500910052013@news.panix.com>

In article <518c7f05$0$29997$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> there is no way to create a C file descriptor in a closed state. Such 
> a thing does not exist. If you have a file descriptor, the file is 
> open. Once you close it, the file descriptor is no longer valid.

Of course there is.

int fd = 37;

I've just created a file descriptor.  There is not enough information 
given to know if it corresponds to an open file or not.

Before you protest that "it's just an int, not a file descriptor", I 
should point out that they're the same thing.  It's pretty common to do 
something like:

for (int fd = 0; fd <= MAX_FD; fd++) {
   close(fd)
}

before forking, to make sure all file descriptors are closed.


From steve+comp.lang.python at pearwood.info  Fri May 10 05:47:37 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 10 May 2013 09:47:37 GMT
Subject: object.enable() anti-pattern
References: <518b88d8$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1512.1368142627.3114.python-list@python.org>
	<518c7f05$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-7584FC.01500910052013@news.panix.com>
Message-ID: <518cc239$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 10 May 2013 01:50:09 -0400, Roy Smith wrote:

> In article <518c7f05$0$29997$c3e8da3$5496439d at news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> 
>> there is no way to create a C file descriptor in a closed state. Such a
>> thing does not exist. If you have a file descriptor, the file is open.
>> Once you close it, the file descriptor is no longer valid.
> 
> Of course there is.
> 
> int fd = 37;
> 
> I've just created a file descriptor.  There is not enough information
> given to know if it corresponds to an open file or not.

No, you haven't created a file descriptor. You've made up a number which 
C will allow you to use as an index into the file descriptor table, 
because C is a high-level assembler with very little in the way of type 
safety, and what little there is you can normally bypass. What you 
haven't done is create the record in the file descriptor table. You can't 
expect that read(fd) or write(fd) will work, although both should fail 
safe rather than segfault if 37 happens to not be an actual file 
descriptor.

What you've done is the moral equivalent of choosing an integer at 
random, coercing it to a pointer, then dereferencing it to peek or poke 
at some memory address. (Although fortunately much safer.)

It's a nice hack, but not one that takes away from what I'm saying.


-- 
Steven


From roy at panix.com  Fri May 10 09:22:31 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 10 May 2013 09:22:31 -0400
Subject: object.enable() anti-pattern
References: <518b88d8$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1512.1368142627.3114.python-list@python.org>
	<518c7f05$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-7584FC.01500910052013@news.panix.com>
	<518cc239$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-85A979.09223110052013@news.panix.com>

In article <518cc239$0$29997$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> > int fd = 37;
> > 
> > I've just created a file descriptor.  There is not enough information
> > given to know if it corresponds to an open file or not.
> 
> No, you haven't created a file descriptor. You've made up a number which 
> C will allow you to use as an index into the file descriptor table, 
> because C is a high-level assembler with very little in the way of type 
> safety, and what little there is you can normally bypass.

No, I've created a file descriptor, which is, by definition, an integer. 
It has nothing to do with C.  This is all defined by the POSIX 
interface.  For example, the getdtablesize(2) man page says:

"The entries in the descriptor table are numbered with small integers 
starting at 0.  The call getdtablesize() returns the size of this table."

So, I am now guaranteed that fds will be ints.  I also know the 
guaranteed minimum and maximum values.

The system even makes certain guarantees which let me predict what file 
descriptor I'll get next in certain situations.  For example, from the 
dup(2) page on my OSX box:

"The new descriptor returned by the call is the lowest numbered 
descriptor currently not in use by the process."

> What you haven't done is create the record in the file descriptor table.

That's correct.  But, as described above, the system makes certain 
guarantees which allow me to reason about the existence or non-existence 
os such entries.

> You can't expect that read(fd) or write(fd) will work

I can expect that they will work if I have reasoned correctly about the 
POSIX-guaranteed semantics.  For example, POSIX says(*) that this C 
program is guaranteed to print, "hello, fd world" (assuming the 
assertion passes):

#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>

int main(int argc, char** argv) {
    int max_files = getdtablesize();
    assert(max_files >= 4);

    for (int i = 3; i < max_files; ++i) {
        close(i);
    }

    dup(2);
    char* message = "hello, fd world\n";
    write(3, message, strlen(message));
}

> What you've done is the moral equivalent of choosing an integer at 
> random, coercing it to a pointer, then dereferencing it to peek or poke 
> at some memory address. (Although fortunately much safer.)

No, what I've done is taken advantage of behaviors which are guaranteed 
by POSIX.

But, we're going off into the weeds here.  Where this started was you 
said:

> There is no sensible use-case for creating a file WITHOUT OPENING
> it. What would be the point?

I agree with you, in general, that it is usually poor design to have 
classes which require instances to be initialized after they are created.

The problem is, you chose as your example a particular domain where the 
underlying objects being modeled have unusual semantics imposed by an 
interface that's 40 years old.  And then you made absolute statements 
about there not possibly ever being certain use cases, when clearly 
there are (for that domain).

-----------------------
(*) Technically, getdtablesize() isn't POSIX, but POSIX does define 
other ways to get the same information.


From cs at zip.com.au  Fri May 10 18:25:41 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Sat, 11 May 2013 08:25:41 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <roy-85A979.09223110052013@news.panix.com>
References: <roy-85A979.09223110052013@news.panix.com>
Message-ID: <20130510222541.GA82778@cskk.homeip.net>

On 10May2013 09:22, Roy Smith <roy at panix.com> wrote:
| In article <518cc239$0$29997$c3e8da3$5496439d at news.astraweb.com>,
|  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
| > > int fd = 37;
| > > 
| > > I've just created a file descriptor.  There is not enough information
| > > given to know if it corresponds to an open file or not.
| > 
| > No, you haven't created a file descriptor. You've made up a number which 
| > C will allow you to use as an index into the file descriptor table, 
| > because C is a high-level assembler with very little in the way of type 
| > safety, and what little there is you can normally bypass.
| 
| No, I've created a file descriptor, which is, by definition, an integer. 
| It has nothing to do with C.  This is all defined by the POSIX 
| interface.  For example, the getdtablesize(2) man page says:
| 
| "The entries in the descriptor table are numbered with small integers 
| starting at 0.  The call getdtablesize() returns the size of this table."
[... snip ...]

I'm with Steven here.

You've made a number that can be used with calls that access the
OS file descriptor table. But it isn't a file descriptor. (Yes, the
in-program number is just a number either way.)

The descriptor table is an in-kernel data structure, filled with
file descriptors. All you have is a label that may or may not access
a file descriptor.

Anyway, we all know _what_ goes on. We're just having terminology issues.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

My computer always does exactly what I tell it to do but sometimes I have
trouble finding out what it was that I told it to do.
        - Dick Wexelblat <rlw at ida.org>


From dreamingforward at gmail.com  Fri May 10 23:16:11 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Fri, 10 May 2013 20:16:11 -0700
Subject: object.enable() anti-pattern
In-Reply-To: <20130510222541.GA82778@cskk.homeip.net>
References: <roy-85A979.09223110052013@news.panix.com>
	<20130510222541.GA82778@cskk.homeip.net>
Message-ID: <CAMjeLr-p8BS1-pBfmod-SymdC+gnW2Nx46A5zKP84c66G9B8QQ@mail.gmail.com>

> | No, I've created a file descriptor, which is, by definition, an integer.
> | It has nothing to do with C.  This is all defined by the POSIX
> | interface.  For example, the getdtablesize(2) man page says:
> |
> | "The entries in the descriptor table are numbered with small integers
> | starting at 0.  The call getdtablesize() returns the size of this table."
> [... snip ...]
>
> I'm with Steven here.
>
> You've made a number that can be used with calls that access the
> OS file descriptor table. But it isn't a file descriptor. (Yes, the
> in-program number is just a number either way.)

Steven, don't be misled.  POSIX is not the model to look to -- it does
not acknowledge that files are actual objects that reside on a piece
of hardware.  It is not simply an integer.

Mark


From dreamingforward at gmail.com  Sat May 11 00:00:02 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Fri, 10 May 2013 21:00:02 -0700
Subject: object.enable() anti-pattern
In-Reply-To: <CAMjeLr-p8BS1-pBfmod-SymdC+gnW2Nx46A5zKP84c66G9B8QQ@mail.gmail.com>
References: <roy-85A979.09223110052013@news.panix.com>
	<20130510222541.GA82778@cskk.homeip.net>
	<CAMjeLr-p8BS1-pBfmod-SymdC+gnW2Nx46A5zKP84c66G9B8QQ@mail.gmail.com>
Message-ID: <CAMjeLr9ddfVCPAT+DDpX4Qz99oANEU_GEzvc38vAKDBiJgK8Jw@mail.gmail.com>

> Steven, don't be misled.  POSIX is not the model to look to -- it does
> not acknowledge that files are actual objects that reside on a piece
> of hardware.  It is not simply an integer.

Please disregard this (my own) flame bait.
-- 
MarkJ
Tacoma, Washington


From nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915 at spamschutz.glglgl.de  Sat May 11 00:21:44 2013
From: nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915 at spamschutz.glglgl.de (Thomas Rachel)
Date: Sat, 11 May 2013 06:21:44 +0200
Subject: object.enable() anti-pattern
In-Reply-To: <roy-85A979.09223110052013@news.panix.com>
References: <518b88d8$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1512.1368142627.3114.python-list@python.org>
	<518c7f05$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-7584FC.01500910052013@news.panix.com>
	<518cc239$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-85A979.09223110052013@news.panix.com>
Message-ID: <kmkh0p$oe0$1@r01.glglgl.de>

Am 10.05.2013 15:22 schrieb Roy Smith:

> That's correct.  But, as described above, the system makes certain
> guarantees which allow me to reason about the existence or non-existence
> os such entries.

Nevertheless, your 37 is not a FD yet.

Let's take your program:

> #include <unistd.h>
> #include <stdio.h>
> #include <string.h>
> #include <assert.h>
>
> int main(int argc, char** argv) {
>      int max_files = getdtablesize();
>      assert(max_files >= 4);

Until here, the numbers 3 toll max_files may or may not be FDs.

>      for (int i = 3; i < max_files; ++i) {
>          close(i);
>      }

Now they are closed; they are definitely no longer FDs even if they 
were. If you would use them in a file operation, you'd get a EBADF which 
means "fd is not a valid file descriptor".

>      dup(2);


 From now on, 3 is a FD and you can use it as such.

>      char* message = "hello, fd world\n";
>      write(3, message, strlen(message));
> }
>

> No, what I've done is taken advantage of behaviors which are guaranteed
> by POSIX.

Maybe, but the integer numbers get or los their property as a file 
descriptor with open() and close() and not by assigning them to an int.


Thomas


From roy at panix.com  Thu May  9 09:07:42 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 09 May 2013 09:07:42 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
Message-ID: <roy-8428A6.09074209052013@news.panix.com>

In article <518b32ef$0$11120$c3e8da3 at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
 
> There is no sensible use-case for creating a file without opening it.

Sure there is.  Sometimes just creating the name in the file system is 
all you want to do.  That's why, for example, the unix "touch" command 
exists.


From oscar.j.benjamin at gmail.com  Thu May  9 09:51:16 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 9 May 2013 14:51:16 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <roy-8428A6.09074209052013@news.panix.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
Message-ID: <CAHVvXxSgPJwza22tqT1irp+SmcV-Xv+oZg7Tp9HyQGdO_uL09g@mail.gmail.com>

On 9 May 2013 14:07, Roy Smith <roy at panix.com> wrote:
> In article <518b32ef$0$11120$c3e8da3 at news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>
>> There is no sensible use-case for creating a file without opening it.
>
> Sure there is.  Sometimes just creating the name in the file system is
> all you want to do.  That's why, for example, the unix "touch" command
> exists.

Wouldn't the code that implements the touch command just look
something like this:

f = open(filename)
f.close()

Or is there some other way of creating the file that doesn't open it
(I mean in general not just in Python)?


Oscar


From steve+comp.lang.python at pearwood.info  Thu May  9 14:21:37 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 18:21:37 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
Message-ID: <518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Thu, 09 May 2013 09:07:42 -0400, Roy Smith wrote:

> In article <518b32ef$0$11120$c3e8da3 at news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>  
>> There is no sensible use-case for creating a file without opening it.
> 
> Sure there is.  Sometimes just creating the name in the file system is
> all you want to do.  That's why, for example, the unix "touch" command
> exists.

Since I neglected to make it clear above that I was still talking about 
file objects, rather than files on disk, I take responsibility for this 
misunderstanding. I thought that since I kept talking about file 
*objects* and *constructors*, people would understand that I was talking 
about in-memory objects rather than on-disk files. Mea culpa.

So, let me rephrase that sentence, and hopefully clear up any further 
misunderstandings.

There is no sensible use-case for creating a file OBJECT unless it 
initially wraps an open file pointer.

This principle doesn't just apply to OOP languages. The standard C I/O 
library doesn't support creating a file descriptor unless it is a file 
descriptor to an open file. open() has the semantics:

"It shall create an open file description that refers to a file and a 
file descriptor that refers to that open file description."

http://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html

and there is no corresponding function to create a *closed* file 
description. (Because such a thing would be pointless.)

Of course language designers are free to design their language to work 
under whatever anti-patterns they desire. I quote from the Pascal 
Language Reference:

"open associates the permanent file file [sic] with a file variable for 
reading or writing. open does not actually open the file; you must call 
reset or rewrite before reading or writing to that file."

http://www.amath.unc.edu/sysadmin/DOC4.0/pascal/lang_ref/
ref_builtin.doc.html


but since that's not a part of standard Pascal, other Pascals may behave 
differently.



-- 
Steven


From python at mrabarnett.plus.com  Thu May  9 14:34:25 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 09 May 2013 19:34:25 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <518BEC31.8030301@mrabarnett.plus.com>

On 09/05/2013 19:21, Steven D'Aprano wrote:
> On Thu, 09 May 2013 09:07:42 -0400, Roy Smith wrote:
>
>> In article <518b32ef$0$11120$c3e8da3 at news.astraweb.com>,
>>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>>
>>> There is no sensible use-case for creating a file without opening it.
>>
>> Sure there is.  Sometimes just creating the name in the file system is
>> all you want to do.  That's why, for example, the unix "touch" command
>> exists.
>
> Since I neglected to make it clear above that I was still talking about
> file objects, rather than files on disk, I take responsibility for this
> misunderstanding. I thought that since I kept talking about file
> *objects* and *constructors*, people would understand that I was talking
> about in-memory objects rather than on-disk files. Mea culpa.
>
> So, let me rephrase that sentence, and hopefully clear up any further
> misunderstandings.
>
> There is no sensible use-case for creating a file OBJECT unless it
> initially wraps an open file pointer.
>
You might want to do this:

f = File(path)
if f.exists():
     ...

This would be an alternative to:

if os.path.exists(path):
     ...

> This principle doesn't just apply to OOP languages. The standard C I/O
> library doesn't support creating a file descriptor unless it is a file
> descriptor to an open file. open() has the semantics:
>
> "It shall create an open file description that refers to a file and a
> file descriptor that refers to that open file description."
>
> http://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html
>
> and there is no corresponding function to create a *closed* file
> description. (Because such a thing would be pointless.)
>
[snip]



From roy at panix.com  Thu May  9 14:59:26 2013
From: roy at panix.com (Roy Smith)
Date: 9 May 2013 14:59:26 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <kmgrme$56s$1@panix2.panix.com>

In article <518be931$0$29997$c3e8da3$5496439d at news.astraweb.com>,
Steven D'Aprano  <steve+comp.lang.python at pearwood.info> wrote:
> There is no sensible use-case for creating a file OBJECT unless it 
> initially wraps an open file pointer.

OK, I guess that's a fair statement.  But mostly because a python file
object only exposes those subset of operations you can do on file
descriptors which deal with reading and writing the contents of a
file.

It would not be true if python file objects included methods for
querying and manipulating file metadata.  It's not hard to imagine a
file class which could be used like:

f = file("/path/to/my/file")
f.delete()

That would be a totally different model from the current python file
object.  And then there would be plenty of things you might want to do
to a file other than open it...

file("/path/to/my/directory").chdir()
file("/dev/sdf").mount("/var/lib/whatever")
file("/mnt/swapfile").swapon()

> The standard C I/O library doesn't support creating a file
> descriptor unless it is a file descriptor to an open file [...]
> there is no corresponding function to create a *closed* file
> description. (Because such a thing would be pointless.)

What about sockets?  From the python standard library:

s = socket.socket()

Now what?  You can't do much with your shiny new socket until you call
bind() or connect(), or a few other things.  At least not for TCP.
This is essentially the two-phased construction pattern.  Of course,
the python socket module just exposes the semantics of the underlying
OS sockets, so there's not a lot of choice there.


From rosuav at gmail.com  Thu May  9 17:55:49 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 07:55:49 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <kmgrme$56s$1@panix2.panix.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmgrme$56s$1@panix2.panix.com>
Message-ID: <CAPTjJmoi9fv5AcEFdcKSWhtrCcrnVXwyf0foZacADOfSHRCmOQ@mail.gmail.com>

On Fri, May 10, 2013 at 4:59 AM, Roy Smith <roy at panix.com> wrote:
> It's not hard to imagine a
> file class which could be used like:
>
> f = file("/path/to/my/file")
> f.delete()
>
> That would be a totally different model from the current python file
> object.  And then there would be plenty of things you might want to do
> to a file other than open it...
>
> file("/path/to/my/directory").chdir()
> file("/dev/sdf").mount("/var/lib/whatever")
> file("/mnt/swapfile").swapon()

Sure, you can imagine it. But what does it do that can't be done with
a moduleful of flat functions accepting strings? This makes sense in
Java, I guess, but why do it in Python?

ChrisA


From steve+comp.lang.python at pearwood.info  Thu May  9 22:30:21 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 10 May 2013 02:30:21 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
Message-ID: <518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Thu, 09 May 2013 19:34:25 +0100, MRAB wrote:

>> There is no sensible use-case for creating a file OBJECT unless it
>> initially wraps an open file pointer.
>>
> You might want to do this:
> 
> f = File(path)
> if f.exists():
>      ...
> 
> This would be an alternative to:
> 
> if os.path.exists(path):
>      ...

Sure, but your made-up File object does not represent a file, it 
represents a pathname which *may or may not* exist. Pathnames are not 
files. Not all files have a pathname that refers to them, and not all 
pathnames point to an actual file. Since it has an exists() method that 
can return False, there are so-called "File" objects that aren't files 
and the name is a misnomer. A much better name for the class would be 
"Path", not "File".

I'm not saying that there is never a use-case for some objects to have an 
"enable" or "start" or "open" method. That would clearly be a silly thing 
to say. In the real world, we design many objects to have a start switch. 
It would be pretty horrible if your car was running all the time. But 
that's because there are actual use-cases for having cars *not* run, and 
"make it stop" is the safe default behaviour.

Your fridge, on the other hand, doesn't have a "make it go" button. So 
long as power is applied to it, your fridge automatically runs. Likewise, 
your watch is an "always on" device, provided it hasn't wound down or 
have a flat battery. Your fire alarm is "always on". 

I must admit I am astonished at how controversial the opinion "if your 
object is useless until you call 'start', you should automatically call 
'start' when the object is created" has turned out to be.



-- 
Steven


From rosuav at gmail.com  Thu May  9 23:08:03 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 13:08:03 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmoRX3m8LC4d4+=QEn87cMeNQBRN3y5iM=3Wb0tTZ9+_zw@mail.gmail.com>

On Fri, May 10, 2013 at 12:30 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> I must admit I am astonished at how controversial the opinion "if your
> object is useless until you call 'start', you should automatically call
> 'start' when the object is created" has turned out to be.

I share your astonishment. This is a very simple point: If, after
constructing an object, the caller MUST call some method on it prior
to the object being of use, then better design is to embed that call
directly into the constructor. As always, it has its exceptions, but
that doesn't stop it being a useful rule.

The Path() equivalent would be:

p = Path()
p.set_path("/foo/bar")
if p.exists():
  pass

Even if you have a set_path() method, it makes good sense to symlink
it to __init__ to avoid this anti-pattern.

C level APIs often have these sorts of initialization requirements.

fd_set selectme;
FD_ZERO(&selectme);

This is because declaring a variable in C cannot initialize it.
Anything that *has* constructors should be using them to set objects
up... that's what they're for.

Where's the controversy?

ChrisA


From roy at panix.com  Thu May  9 23:09:55 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 09 May 2013 23:09:55 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-6D8B98.23095509052013@news.panix.com>

In article <518c5bbc$0$29997$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> I must admit I am astonished at how controversial the opinion "if your 
> object is useless until you call 'start', you should automatically call 
> 'start' when the object is created" has turned out to be.

I'm sorry.  I thought you were here for an argument.

I think where things went pear shaped is when you made the statement:

>> There is no sensible use-case for creating a file OBJECT unless it
>> initially wraps an open file pointer.

That's a pretty absolute point of view.  Life is rarely so absolute.


From dreamingforward at gmail.com  Thu May  9 23:19:05 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Thu, 9 May 2013 20:19:05 -0700
Subject: object.enable() anti-pattern
In-Reply-To: <roy-6D8B98.23095509052013@news.panix.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
Message-ID: <CAMjeLr9m9pSzE7QMVyCB8WRaL8oVi2+_NsbBZYgqJAjUYEwspg@mail.gmail.com>

> I think where things went pear shaped is when you made the statement:
>
>>> There is no sensible use-case for creating a file OBJECT unless it
>>> initially wraps an open file pointer.
>
> That's a pretty absolute point of view.  Life is rarely so absolute.

In the old days, it was useful to have fine-grained control over the
file object because you didn't know where it might fail, and the OS
didn't necessarily give you give good status codes.  So being able to
step through the entire process was the job of the progammers.

Now, with languages so high like python and hardware so common, it
almost is never necessary, so he has some point.   A closed file
pointer is useful from a OS-progamming point-of-view though because
you generally never want to leave files open where they'd block other
I/O.


-- 
MarkJ
Tacoma, Washington


From rosuav at gmail.com  Thu May  9 23:46:25 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 13:46:25 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <CAMjeLr9m9pSzE7QMVyCB8WRaL8oVi2+_NsbBZYgqJAjUYEwspg@mail.gmail.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<CAMjeLr9m9pSzE7QMVyCB8WRaL8oVi2+_NsbBZYgqJAjUYEwspg@mail.gmail.com>
Message-ID: <CAPTjJmpPndLkbfd5HQZPFog6jOvBp1wx54P2iY2SZE1Fyf63kQ@mail.gmail.com>

On Fri, May 10, 2013 at 1:19 PM, Mark Janssen <dreamingforward at gmail.com> wrote:
>> I think where things went pear shaped is when you made the statement:
>>
>>>> There is no sensible use-case for creating a file OBJECT unless it
>>>> initially wraps an open file pointer.
>>
>> That's a pretty absolute point of view.  Life is rarely so absolute.
>
> In the old days, it was useful to have fine-grained control over the
> file object because you didn't know where it might fail, and the OS
> didn't necessarily give you give good status codes.  So being able to
> step through the entire process was the job of the progammers.

I don't know what you mean by the "old days", but a couple of decades
ago, there were no such things as "file objects". You call a function
to open a file, you get back a number. You explicitly close that by
calling another function and passing it that number. In fact, there is
no way to have a "file object" that doesn't have an open file
associated with it, because it's simply... a number.

> Now, with languages so high like python and hardware so common, it
> almost is never necessary, so he has some point.   A closed file
> pointer is useful from a OS-progamming point-of-view though because
> you generally never want to leave files open where they'd block other
> I/O.

I'm beginning to wonder if you and Dihedral are swapping notes.
Dihedral's been sounding fairly coherent lately.

ChrisA


From dreamingforward at gmail.com  Thu May  9 23:51:51 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Thu, 9 May 2013 20:51:51 -0700
Subject: object.enable() anti-pattern
In-Reply-To: <CAPTjJmpPndLkbfd5HQZPFog6jOvBp1wx54P2iY2SZE1Fyf63kQ@mail.gmail.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<CAMjeLr9m9pSzE7QMVyCB8WRaL8oVi2+_NsbBZYgqJAjUYEwspg@mail.gmail.com>
	<CAPTjJmpPndLkbfd5HQZPFog6jOvBp1wx54P2iY2SZE1Fyf63kQ@mail.gmail.com>
Message-ID: <CAMjeLr_2hV9w8320B4oNCnHeq-dGOaJaKEdk1O4xx6h6xyRggA@mail.gmail.com>

>> In the old days, it was useful to have fine-grained control over the
>> file object because you didn't know where it might fail, and the OS
>> didn't necessarily give you give good status codes.  So being able to
>> step through the entire process was the job of the progammers.
>
> I don't know what you mean by the "old days", but a couple of decades
> ago, there were no such things as "file objects".

My apologies.  I used the word "object" when I shouldn't have.

> I'm beginning to wonder if you and Dihedral are swapping notes.
> Dihedral's been sounding fairly coherent lately.

Dihedral...  That's my dream-self.  Where did you encounter him?  heh

-- 
MarkJ
Tacoma, Washington


From steve+comp.lang.python at pearwood.info  Fri May 10 01:03:10 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 10 May 2013 05:03:10 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
Message-ID: <518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Thu, 09 May 2013 23:09:55 -0400, Roy Smith wrote:

> In article <518c5bbc$0$29997$c3e8da3$5496439d at news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> 
>> I must admit I am astonished at how controversial the opinion "if your
>> object is useless until you call 'start', you should automatically call
>> 'start' when the object is created" has turned out to be.
> 
> I'm sorry.  I thought you were here for an argument.

No, I'm here for the abuse.


> I think where things went pear shaped is when you made the statement:
> 
>>> There is no sensible use-case for creating a file OBJECT unless it
>>> initially wraps an open file pointer.
> 
> That's a pretty absolute point of view.  Life is rarely so absolute.

So far the only counter-examples given aren't counter-examples. One 
involves opening the file. The other involves something which isn't a 
file, but a string instead. If there are any counter-examples, they are 
impossible in Python and C: you cannot create a file object in Python 
without opening it, and you cannot create a file descriptor in C without 
opening it. But not in Pascal, which actually supports my claim that this 
is an anti-pattern: while some Pascal implementations do allow you to 
create a non-open file, you cannot do *anything* with it until you open 
it, except generate bugs.



-- 
Steven


From dan at tombstonezero.net  Fri May 10 02:22:31 2013
From: dan at tombstonezero.net (Dan Sommers)
Date: Fri, 10 May 2013 06:22:31 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <Hm0jt.6$I26.5@newsfe26.iad>

On Fri, 10 May 2013 05:03:10 +0000, Steven D'Aprano wrote:

>>>> There is no sensible use-case for creating a file OBJECT unless it
>>>> initially wraps an open file pointer.

> So far the only counter-examples given aren't counter-examples ...

Well, sure, if you discount operations like "create this file" and
queries like "could I delete this file if I wanted to?" [0] as methods
of the file system rather than of a hypothetical file object.

What about a distributed system?  Suppose I want to create a file object
in one place, and send that object to the another place for the file to
be read from or written to [1]?  Suppose that for security reasons, I
have to do it that way, because the first place can only create the
objects, and the second place can only access the underly file contents
through an existing object?

I suppose that this case exists even in a non-distributed system that
allows whatever execution unit exists to change its own security
settings (POSIX has setuid and setgid functions), or exposes file ACLs
as methods of file objects rather than of the OS or file system.

What, exactly, does a "file object" represent?

And going back to your original comment (which was actually in response
to one of my posts), at least some operations on python file objects
*could* succeed without having to open the file.  An OS could provide
truncate, or writeable, on un-opened files; and certainly Python could
provide encoding, or isatty, on un-opened files.  Of these, truncate
might be the closest use case of creating a file object without any
intent to write to it, for some definition of "write to it."

Dan

[0] Yes, I understand that asking first instead of trying to delete the
file is just asking to lose any number of potential race conditions,
assuming that your system even supports race conditions.

[1] Think about a multi-threaded (or otherwise distributed) FTP or HTTP
server.  No, don't think about the server vs. the client, but rather a
"core" server overseeing "sub" servers for different sessions.


From steve+comp.lang.python at pearwood.info  Fri May 10 07:00:49 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 10 May 2013 11:00:49 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
Message-ID: <518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 10 May 2013 06:22:31 +0000, Dan Sommers wrote:

> On Fri, 10 May 2013 05:03:10 +0000, Steven D'Aprano wrote:
> 
>>>>> There is no sensible use-case for creating a file OBJECT unless it
>>>>> initially wraps an open file pointer.
> 
>> So far the only counter-examples given aren't counter-examples ...
> 
> Well, sure, if you discount operations like "create this file" and
> queries like "could I delete this file if I wanted to?" [0] as methods
> of the file system rather than of a hypothetical file object.
> 
> What about a distributed system?  Suppose I want to create a file object
> in one place, and send that object to the another place for the file to
> be read from or written to [1]?  Suppose that for security reasons, I
> have to do it that way, because the first place can only create the
> objects, and the second place can only access the underly file contents
> through an existing object?

Unless you have re-implemented the file I/O system, it doesn't matter. If 
your file objects are based on C I/O, then even if the first server 
cannot read or write to the files it still creates file objects in an 
open state, because that is how C works.

Or maybe the first server only creates some sort of proxy to the real 
underlying file object. Or maybe you're re-implemented the I/O system, 
and aren't following C's design. Since you're just making this up as a 
thought experiment, anything is possible.

But either way, that's fine. You've found an object where it does make 
sense to have an explicit "make it go" method: first one entity has 
permission to construct the object, but not to open the underlying file. 
Another entity has permission to open the underlying file, but not to 
create the object. I have no idea whether this is a reasonable security 
design or not, it actually sounds a bit rubbish to me but what do I know? 
So let's treat it as a reasonable design. 

As I've said, repeatedly, that's not what I'm talking about.

When you DON'T have useful things that can be done with the object before 
calling "enable", then it is an anti-pattern to require a separate call 
to "enable" method, and the enable functionality should be moved into the 
object constructor. If you DO have useful things that can be done, like 
pass the object to another entity, for security, then that's a whole 
'nuther story.

Really, what I'm describing is *normal* behaviour for most objects. We 
don't usually design APIs like this:

n = int("42")
n.enable()
m = n + 1
m.enable()
x = m*2 + n*3
print x - 1  # oops, raises because I forgot to call x.enable()

That's a rubbish API, and for simple data-like objects, we all agree it 
is a rubbish API. So why accept the same rubbish API just because the 
object is more complicated? If you don't have a good, reasonable, non-
contrived use-case for a separate "make it go" method, don't use one.


For my next controversial opinion, I'm going to argue that we should do 
arithmetic using numbers rather than by inserting lists inside other 
lists:

# Do this:

count = 0
count += 1

# Not this:

count = []
count.insert(0, [])


*wink*


-- 
Steven


From robert.kern at gmail.com  Fri May 10 08:19:05 2013
From: robert.kern at gmail.com (Robert Kern)
Date: Fri, 10 May 2013 13:19:05 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <kmiojk$12i$1@ger.gmane.org>

On 2013-05-10 12:00, Steven D'Aprano wrote:

> But either way, that's fine. You've found an object where it does make
> sense to have an explicit "make it go" method: first one entity has
> permission to construct the object, but not to open the underlying file.
> Another entity has permission to open the underlying file, but not to
> create the object. I have no idea whether this is a reasonable security
> design or not, it actually sounds a bit rubbish to me but what do I know?
> So let's treat it as a reasonable design.
>
> As I've said, repeatedly, that's not what I'm talking about.
>
> When you DON'T have useful things that can be done with the object before
> calling "enable", then it is an anti-pattern to require a separate call
> to "enable" method, and the enable functionality should be moved into the
> object constructor. If you DO have useful things that can be done, like
> pass the object to another entity, for security, then that's a whole
> 'nuther story.

I'd be curious to see in-the-wild instances of the anti-pattern that you are 
talking about, then. I think everyone agrees that entirely unmotivated "enable" 
methods should be avoided, but I have my doubts that they come up very often. Do 
programmers have a natural tendency to make an extra, completely unnecessary 
method? I would think that they have a natural tendency to the opposite.

In my experience, everyone has a reason in mind when they follow a 
pattern/anti-pattern. It is pretty rare that someone just does some specific, 
nameable thing for no reason at all. There is no need to call out an 
anti-pattern for which no one has a reason to do it. But there is a continuum of 
reasons. Some reasons are better than others. Some reasons only apply in a small 
set of circumstances but seem like they would apply more generally, at least to 
novice programmers. Programmers can be wrong about what they think the 
(anti-)pattern actually achieves. The whole point of naming an anti-pattern is 
to discuss those reasons, show where they are misapplied, where YAGNI, why 
novices overuse it, other patterns that should be used instead, and also the 
circumstances where it is actually a good pattern instead.

To artificially limit the discussion of the anti-pattern to the trivial, 
entirely unmotivated case forbids most of the interesting and instructive parts 
of the conversation.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco



From storchaka at gmail.com  Fri May 10 11:44:35 2013
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Fri, 10 May 2013 18:44:35 +0300
Subject: object.enable() anti-pattern
In-Reply-To: <kmiojk$12i$1@ger.gmane.org>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
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	<kmiojk$12i$1@ger.gmane.org>
Message-ID: <kmj9mq$2la$1@ger.gmane.org>

10.05.13 15:19, Robert Kern ???????(??):
> I'd be curious to see in-the-wild instances of the anti-pattern that you
> are talking about, then.

Many (if not most) GUI frameworks use this pattern.

     button = Button("text")
     button.setForegroundColor(...)
     button.setBackgoundColor(...)
     button.setFont(...)
     button.setRelief(...)
     button.setBorder(...)
     button.setWidth(...)
     button.setAction(...)
     button.setMouseListener(...)
     button.place(...)

Another example is running a subprocess in Unix-like systems.

     fork()
     open/close file descriptors, set limits, etc
     exec*()




From robert.kern at gmail.com  Fri May 10 13:20:34 2013
From: robert.kern at gmail.com (Robert Kern)
Date: Fri, 10 May 2013 18:20:34 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <kmj9mq$2la$1@ger.gmane.org>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
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	<kmiojk$12i$1@ger.gmane.org> <kmj9mq$2la$1@ger.gmane.org>
Message-ID: <kmja8u$9h6$1@ger.gmane.org>

On 2013-05-10 16:44, Serhiy Storchaka wrote:
> 10.05.13 15:19, Robert Kern ???????(??):
>> I'd be curious to see in-the-wild instances of the anti-pattern that you
>> are talking about, then.
>
> Many (if not most) GUI frameworks use this pattern.
>
>      button = Button("text")
>      button.setForegroundColor(...)
>      button.setBackgoundColor(...)
>      button.setFont(...)
>      button.setRelief(...)
>      button.setBorder(...)
>      button.setWidth(...)
>      button.setAction(...)
>      button.setMouseListener(...)
>      button.place(...)
>
> Another example is running a subprocess in Unix-like systems.
>
>      fork()
>      open/close file descriptors, set limits, etc
>      exec*()

According to Steven's criteria, neither of these are instances of the 
anti-pattern because there are good reasons they are this way. He is reducing 
the anti-pattern to just those cases where there is no reason for doing so. That 
is why I asked for in-the-wild instances. I should have qualified my sentence to 
include "according to your criteria" because people seem to be answering my 
query out of that context.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco



From rosuav at gmail.com  Fri May 10 13:24:59 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 11 May 2013 03:24:59 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <kmj9mq$2la$1@ger.gmane.org>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
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	<kmiojk$12i$1@ger.gmane.org> <kmj9mq$2la$1@ger.gmane.org>
Message-ID: <CAPTjJmqd+nCGB9P2NLSsrbukO3-wtPiyST9DY0GnCf2nbiX4tw@mail.gmail.com>

On Sat, May 11, 2013 at 1:44 AM, Serhiy Storchaka <storchaka at gmail.com> wrote:
> 10.05.13 15:19, Robert Kern ???????(??):
>
>> I'd be curious to see in-the-wild instances of the anti-pattern that you
>> are talking about, then.
>
>
> Many (if not most) GUI frameworks use this pattern.
>
>     button = Button("text")
>     button.setForegroundColor(...)
>     button.setBackgoundColor(...)
>     button.setFont(...)
>     button.setRelief(...)
>     button.setBorder(...)
>     button.setWidth(...)
>     button.setAction(...)
>     button.setMouseListener(...)
>     button.place(...)

The button really exists, though. You could merge the creation and
placement (or in the case of a window/dialog, the creation and
showing), but it's often useful to not. However, in the specific case
you have there, there's an alternative: a mapping of attributes and
values passed to the constructor, and then you could pass the
constructed object directly to a place(). That would let you, if you
wished, effectively construct a Button with a parent right there,
which makes reasonable sense.

> Another example is running a subprocess in Unix-like systems.
>
>     fork()
>     open/close file descriptors, set limits, etc
>     exec*()

Hrm. Not really a corresponding example. After you fork, you have two
actual processes. Following up with an exec is only one of the
possible options; I've done code that forks and execs, and code that
forks and keeps running, and neither of them feels "wrong" in any way.
There IS a function that's similar to what you're saying, and that's
vfork:

"""
(From POSIX.1) The vfork() function has the same effect as fork(2),
except that the behavior is undefined if the process created by
vfork() either modifies any data other than a variable of type pid_t
used to store the return value from vfork(), or returns from the
function in which vfork() was called, or calls any other function
before successfully calling _exit(2) or one of the exec(3) family of
functions.
"""

It's deprecated because it's so fragile (and because regular fork()
isn't that much less efficient now; AIUI, vfork was meant to be a
lightweight fork). I would say that the deprecation of vfork in favour
of fork is a strong indication that the object.enable() anti-pattern
can come up in kernel APIs too, and isn't liked there either.

ChrisA


From steve+comp.lang.python at pearwood.info  Sat May 11 03:51:53 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 11 May 2013 07:51:53 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmiojk$12i$1@ger.gmane.org> <kmj9mq$2la$1@ger.gmane.org>
	<mailman.1542.1368206453.3114.python-list@python.org>
Message-ID: <518df898$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 10 May 2013 18:20:34 +0100, Robert Kern wrote:

> According to Steven's criteria, neither of these are instances of the
> anti-pattern because there are good reasons they are this way. He is
> reducing the anti-pattern to just those cases where there is no reason
> for doing so. 

But isn't that the case for all anti-patterns?

We agree that GOTO is an anti-pattern. That doesn't mean that there 
aren't valid reasons for using GOTO. Sometimes there are good use-cases 
for GOTO that outweigh the harm. By calling it an anti-pattern, though, 
we shift the onus onto the person wanting to use GOTO: justify why you 
need it, or use something else.

Would you object less if I called it a "code smell" than an "anti-
pattern"? If so, I accept your criticism, and call it a code smell: the 
less temporal coupling your API has, the better.


> That is why I asked for in-the-wild instances. 

How about this?

http://legacy.thecodewhisperer.com/post/366626867/improving-clarity-by-removing-temporal-coupling


Another example of temporal coupling is json_decode in PHP: you must 
follow it by a call to json_last_error, otherwise you have no way of 
telling whether the json_decode function succeeded or not.

http://php.net/manual/en/function.json-last-error.php


> I should
> have qualified my sentence to include "according to your criteria"
> because people seem to be answering my query out of that context.

Now you know how I feel :-)

I started this thread asking for help tracking down a blog post 
describing this code smell, or at least the name of such. Thanks again to 
Wayne Werner, who came through with the name of the anti-pattern, 
temporal coupling, and a blog post describing it, although not the one I 
read all those many moons ago.

I never intended to give the impression that *any* use of a separate 
"enable" method call was bad. I certainly didn't intend to be bogged 
down into a long discussion about the minutia of file descriptors in 
C, but it was educational :-)



-- 
Steven


From roy at panix.com  Sat May 11 09:31:12 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 11 May 2013 09:31:12 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmiojk$12i$1@ger.gmane.org> <kmj9mq$2la$1@ger.gmane.org>
	<mailman.1542.1368206453.3114.python-list@python.org>
	<518df898$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-6A558E.09311211052013@news.panix.com>

In article <518df898$0$29997$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> I never intended to give the impression that *any* use of a separate 
> "enable" method call was bad. I certainly didn't intend to be bogged 
> down into a long discussion about the minutia of file descriptors in 
> C, but it was educational :-)

Well, you did say you were here for abuse.  I think you got your money's 
worth.  Can I interest you in a course of getting hit on the head 
lessons?

And just to be clear to the studio audience and all of you who are 
watching at home...

For all the effort I put into nit-picking, I do agree with Steven's 
basic premise.  Two-phase construction is usually not the right way to 
be designing classes.  Especially in languages like Python where 
constructors raising exceptions is both inexpensive and universally 
accepted as normal behavior.


From robert.kern at gmail.com  Sat May 11 15:55:49 2013
From: robert.kern at gmail.com (Robert Kern)
Date: Sat, 11 May 2013 20:55:49 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <518df898$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmiojk$12i$1@ger.gmane.org> <kmj9mq$2la$1@ger.gmane.org>
	<mailman.1542.1368206453.3114.python-list@python.org>
	<518df898$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <kmm7o0$dc8$1@ger.gmane.org>

On 2013-05-11 08:51, Steven D'Aprano wrote:
> On Fri, 10 May 2013 18:20:34 +0100, Robert Kern wrote:
>
>> According to Steven's criteria, neither of these are instances of the
>> anti-pattern because there are good reasons they are this way. He is
>> reducing the anti-pattern to just those cases where there is no reason
>> for doing so.
>
> But isn't that the case for all anti-patterns?
>
> We agree that GOTO is an anti-pattern. That doesn't mean that there
> aren't valid reasons for using GOTO. Sometimes there are good use-cases
> for GOTO that outweigh the harm. By calling it an anti-pattern, though,
> we shift the onus onto the person wanting to use GOTO: justify why you
> need it, or use something else.

Yes, that was the point I was making. You seemed to be defining away the 
legitimate instances as not instances of the pattern at all because they were 
legitimate, and that appeared to me to be defeating the purpose of having the 
discussion.

On a related note, I *don't* think it's a good idea to phrase it as "justify why 
you need it". I don't think that gives very good guidance to a novice when they 
are given the task of designing something. People can come up with a 
justification for just about anything, especially when they are only justifying 
things to themselves. I think it's more important to just talk about the 
situations where a pattern is useful, and the common situations where people, 
for whatever reason, *think* that a pattern is useful, but isn't. Naming it a 
Pattern or Anti-pattern is really just a measure of how bad the latter half of 
that is compared to the first half, and is less interesting than the discussion 
itself. That's why I had a bug up my ass about what looked like the exclusion of 
the "good" uses. It's the good examples that give novices an idea of what a good 
justification looks like, so they can tell if the justification they are giving 
themselves measures up.

> Would you object less if I called it a "code smell" than an "anti-
> pattern"? If so, I accept your criticism, and call it a code smell: the
> less temporal coupling your API has, the better.

That was not really my objection. I was objecting to the way you appeared to be 
defining the particular pattern in question. But as we appear to agree on the 
important matters, I won't press it further.

>> That is why I asked for in-the-wild instances.
>
> How about this?
>
> http://legacy.thecodewhisperer.com/post/366626867/improving-clarity-by-removing-temporal-coupling

There's something about Java mixedCase that makes my eyes glaze, so I'll take 
your word for it. :-)

> Another example of temporal coupling is json_decode in PHP: you must
> follow it by a call to json_last_error, otherwise you have no way of
> telling whether the json_decode function succeeded or not.
>
> http://php.net/manual/en/function.json-last-error.php

I suspect that the author might say something about error checking being 
optional. But yeah, terrible API. :-)

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco



From rosuav at gmail.com  Sat May 11 18:39:26 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 12 May 2013 08:39:26 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <kmm7o0$dc8$1@ger.gmane.org>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmiojk$12i$1@ger.gmane.org> <kmj9mq$2la$1@ger.gmane.org>
	<mailman.1542.1368206453.3114.python-list@python.org>
	<518df898$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmm7o0$dc8$1@ger.gmane.org>
Message-ID: <CAPTjJmpx5e2i_JWjk5PVdiENY-3DGqO0ZtrNnX4M5SCbYBQOLw@mail.gmail.com>

On Sun, May 12, 2013 at 5:55 AM, Robert Kern <robert.kern at gmail.com> wrote:
>> Another example of temporal coupling is json_decode in PHP: you must
>> follow it by a call to json_last_error, otherwise you have no way of
>> telling whether the json_decode function succeeded or not.
>>
>> http://php.net/manual/en/function.json-last-error.php
>
>
> I suspect that the author might say something about error checking being
> optional. But yeah, terrible API. :-)

The problem with that one isn't that error checking is optional, but
that errors are signalled with a perfectly legal return value (FALSE,
if I recall correctly - which is also returned if you json_decode a
boolean false). Better design would either throw an exception on
error, or have a unique sentinel representing the errorness of the
return value.

ChrisA


From ndparker at gmail.com  Sat May 11 11:33:51 2013
From: ndparker at gmail.com (=?UTF-8?B?QW5kcsOp?= Malo)
Date: Sat, 11 May 2013 17:33:51 +0200
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmiojk$12i$1@ger.gmane.org>
	<mailman.1541.1368205876.3114.python-list@python.org>
Message-ID: <2048586.oD9bP8C7rC@news.perlig.de>

* Serhiy Storchaka wrote:

> Another example is running a subprocess in Unix-like systems.
> 
>      fork()
>      open/close file descriptors, set limits, etc
>      exec*()

For running a subprocess, only fork() is needed. For starting another
executable, only exec() is needed. For running the new executable in a
subprocess fork() and exec() are needed. I think, that's a bad example.
These APIs are actually well-designed.

nd
-- 
Gefunden auf einer "Webdesigner"-Seite:
        > Programmierung in HTML, XML, WML, CGI, FLASH <

# Andr? Malo # http://pub.perlig.de/ #


From rosuav at gmail.com  Sat May 11 12:04:50 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 12 May 2013 02:04:50 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <2048586.oD9bP8C7rC@news.perlig.de>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmiojk$12i$1@ger.gmane.org>
	<mailman.1541.1368205876.3114.python-list@python.org>
	<2048586.oD9bP8C7rC@news.perlig.de>
Message-ID: <CAPTjJmppMXNnFB56yUPAXzj38DP6ycd9NqDHAMceRvmRUdQiOA@mail.gmail.com>

On Sun, May 12, 2013 at 1:33 AM, Andr? Malo <ndparker at gmail.com> wrote:
> * Serhiy Storchaka wrote:
>
>> Another example is running a subprocess in Unix-like systems.
>>
>>      fork()
>>      open/close file descriptors, set limits, etc
>>      exec*()
>
> For running a subprocess, only fork() is needed. For starting another
> executable, only exec() is needed. For running the new executable in a
> subprocess fork() and exec() are needed. I think, that's a bad example.
> These APIs are actually well-designed.

That said, though, there's certainly plenty of room for one-call APIs
like popen. For the simple case where you want to start a process with
some other executable, wait for it to finish, and then work with its
return value, it makes sense to hide the details of fork/exec/wait -
especially since that simple API can be cross-platform, where fork()
itself is quite hard to implement on Windows.

ChrisA


From wayne at waynewerner.com  Sun May 12 12:48:58 2013
From: wayne at waynewerner.com (Wayne Werner)
Date: Sun, 12 May 2013 11:48:58 -0500 (CDT)
Subject: object.enable() anti-pattern
In-Reply-To: <kmiojk$12i$1@ger.gmane.org>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmiojk$12i$1@ger.gmane.org>
Message-ID: <alpine.DEB.2.02.1305121124050.3322@gilgamesh>

On Fri, 10 May 2013, Robert Kern wrote:

> On 2013-05-10 12:00, Steven D'Aprano wrote:
>
>> But either way, that's fine. You've found an object where it does make
>> sense to have an explicit "make it go" method: first one entity has
>> permission to construct the object, but not to open the underlying file.
>> Another entity has permission to open the underlying file, but not to
>> create the object. I have no idea whether this is a reasonable security
>> design or not, it actually sounds a bit rubbish to me but what do I know?
>> So let's treat it as a reasonable design.
>> 
>> As I've said, repeatedly, that's not what I'm talking about.
>> 
>> When you DON'T have useful things that can be done with the object before
>> calling "enable", then it is an anti-pattern to require a separate call
>> to "enable" method, and the enable functionality should be moved into the
>> object constructor. If you DO have useful things that can be done, like
>> pass the object to another entity, for security, then that's a whole
>> 'nuther story.
>
> I'd be curious to see in-the-wild instances of the anti-pattern that you are 
> talking about, then. I think everyone agrees that entirely unmotivated 
> "enable" methods should be avoided, but I have my doubts that they come up 
> very often. Do programmers have a natural tendency to make an extra, 
> completely unnecessary method? I would think that they have a natural 
> tendency to the opposite.
>
> In my experience, everyone has a reason in mind when they follow a 
> pattern/anti-pattern. It is pretty rare that someone just does some specific, 
> nameable thing for no reason at all. There is no need to call out an 
> anti-pattern for which no one has a reason to do it. But there is a continuum 
> of reasons. Some reasons are better than others. Some reasons only apply in a 
> small set of circumstances but seem like they would apply more generally, at 
> least to novice programmers. Programmers can be wrong about what they think 
> the (anti-)pattern actually achieves. The whole point of naming an 
> anti-pattern is to discuss those reasons, show where they are misapplied, 
> where YAGNI, why novices overuse it, other patterns that should be used 
> instead, and also the circumstances where it is actually a good pattern 
> instead.

I'll share the anti-pattern that I've seen many times (not actually in 
Python)

     class CoolPresenter:
         def __init__(self):
             self.view = None
             self.some_property = None
             self.other_property = None

         def initialize(self):
             self.view.disable()
             data = self.load_data()
             self.view.data = data
             self.view.enable()


         def reload(self):
             if self.view is None:
                 raise NotInitializedError("Error: Please setup class")
             self.view.disable()
             data = self.load_data()
             self.view.data = data
             self.view.enable()



Then you would see code like this:

     presenter = CoolPresenter()
     presenter.view = CoolView()

This is just plain silly for a few reasons:

     - It's ambiguous. I don't know what's required for the CoolPresenter
       to function properly.

     - The temporal coupling mentioned earlier. I can create an instance of
       a class and then call a function (say `reload`) and then boom! My
       program crashes. There is *no possible* use case of this class where
       you can use it without a view.


The motivation behind this anti-pattern that I've seen is the desire to 
not have a constructor that "does too much". So you end out with an empty 
constructor and temporal coupling, and a terrible API that doesn't clearly 
explain the requirements of the class. Your class constructor should 
*require* everything that is necessary to have a stable state when the 
class is created (i.e. you should be able to properly call any function, 
set any property without an exception happening)

Why? Less bugs, easier to comprehend, change/update your code. Easier to 
use the class.

-W


From tjreedy at udel.edu  Sun May 12 16:23:58 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 12 May 2013 16:23:58 -0400
Subject: object.enable() anti-pattern
In-Reply-To: <alpine.DEB.2.02.1305121124050.3322@gilgamesh>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<kmiojk$12i$1@ger.gmane.org>
	<alpine.DEB.2.02.1305121124050.3322@gilgamesh>
Message-ID: <kmotoh$27n$1@ger.gmane.org>

On 5/12/2013 12:48 PM, Wayne Werner wrote:

> I'll share the anti-pattern that I've seen many times (not actually in
> Python)
>
>      class CoolPresenter:
>          def __init__(self):
>              self.view = None
>              self.some_property = None
>              self.other_property = None
>
>          def initialize(self):
>              self.view.disable()
>              data = self.load_data()
>              self.view.data = data
>              self.view.enable()
>
>
>          def reload(self):
>              if self.view is None:
>                  raise NotInitializedError("Error: Please setup class")
>              self.view.disable()
>              data = self.load_data()
>              self.view.data = data
>              self.view.enable()
>
>
>
> Then you would see code like this:
>
>      presenter = CoolPresenter()
>      presenter.view = CoolView()
>
> This is just plain silly for a few reasons:
>
>      - It's ambiguous. I don't know what's required for the CoolPresenter
>        to function properly.
>
>      - The temporal coupling mentioned earlier. I can create an instance of
>        a class and then call a function (say `reload`) and then boom! My
>        program crashes. There is *no possible* use case of this class where
>        you can use it without a view.

Thank you for this examples. It makes Steven's point clearer than the 
'file object' example. The problem with the latter is that objectors 
could could point to file path objects, which are used to do some 
manipulations of files and directory entries on the storage device 
*without looking at the specific file data*. Such file data, as opposed 
to directory data, never enters the program data space and with smart 
enough devices, need not enter the CPU and its RAM. They could then 
confuse them with file access objects which are used to transfer 
specific data *between* files and program data space. The confusion is 
adied by the fact that file path objects are used to create file access 
objects. They do separate jobs and it seems that they are well kept 
separate, even if there are languages where file path objects can have 
file access functions turned on and off.

> The motivation behind this anti-pattern that I've seen is the desire to
> not have a constructor that "does too much". So you end out with an
> empty constructor and temporal coupling, and a terrible API that doesn't
> clearly explain the requirements of the class. Your class constructor
> should *require* everything that is necessary to have a stable state
> when the class is created (i.e. you should be able to properly call any
> function, set any property without an exception happening)
>
> Why? Less bugs, easier to comprehend, change/update your code. Easier to
> use the class.


--
Terry Jan Reedy





From roy at panix.com  Fri May 10 10:01:14 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 10 May 2013 10:01:14 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1527.1368188358.3114.python-list@python.org>
Message-ID: <roy-F6FC44.10011410052013@news.panix.com>

In article <mailman.1527.1368188358.3114.python-list at python.org>,
 Robert Kern <robert.kern at gmail.com> wrote:

> I'd be curious to see in-the-wild instances of the anti-pattern that 
> you are talking about, then. I think everyone agrees that entirely 
> unmotivated "enable" methods should be avoided, but I have my doubts 
> that they come up very often. 

As I mentioned earlier in this thread, this was a common pattern in the 
early days of C++, when exceptions were a new concept and handled poorly 
by many compilers (and, for that matter, programmers).

There was a school of thought that constructors should never be able to 
fail (because the only way for a constructor to fail is to throw an 
exception).  The pattern was to always have the constructor succeed, and 
then either have a way to check to see if the newly-constructed object 
was valid, or have a separate post-construction initialization step 
which could fail.

See, for example, the isValid() and Exists() calls for RogueWave's 
RWFile class (http://tinyurl.com/c8kv26g).  And also, 
http://tinyurl.com/cgs6clx.

Even today, there are C++ implementations which do not use exceptions.  
Some are for use in embedded or real-time systems where things need to 
be strictly time-bound and/or memory-bound.  Others are for historical 
reasons (http://tinyurl.com/6hn4zo).

Once people were used to writing "can't fail" constructors in C++, they 
often continued using that pattern in other languages, where the 
underlying reasons no longer made sense.  Quite possibly, they never 
even knew the underlying reasons; they were taught, "Constructors must 
never fail", and assumed it was a universal rule.

This, BTW, is one of my biggest beefs with the classic Gang Of Four 
pattern book.  It presents a bunch of patterns as being universally 
applicable, when in reality many (if not most) of them are highly C++ 
specific.

BTW, whenever I read things like, "I think everyone agrees", I 
automatically assume what the writer really meant was, "I, and all the 
people who agree with me, think".


From oscar.j.benjamin at gmail.com  Fri May 10 10:29:00 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Fri, 10 May 2013 15:29:00 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <roy-F6FC44.10011410052013@news.panix.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1527.1368188358.3114.python-list@python.org>
	<roy-F6FC44.10011410052013@news.panix.com>
Message-ID: <CAHVvXxTzrASOEFzvF+_LaviN0W9u3NTVvNgkJnuP4eiMkevcpQ@mail.gmail.com>

On 10 May 2013 15:01, Roy Smith <roy at panix.com> wrote:
> In article <mailman.1527.1368188358.3114.python-list at python.org>,
>  Robert Kern <robert.kern at gmail.com> wrote:
>
>> I'd be curious to see in-the-wild instances of the anti-pattern that
>> you are talking about, then. I think everyone agrees that entirely
>> unmotivated "enable" methods should be avoided, but I have my doubts
>> that they come up very often.
>
> As I mentioned earlier in this thread, this was a common pattern in the
> early days of C++, when exceptions were a new concept and handled poorly
> by many compilers (and, for that matter, programmers).
>
> There was a school of thought that constructors should never be able to
> fail (because the only way for a constructor to fail is to throw an
> exception).  The pattern was to always have the constructor succeed, and
> then either have a way to check to see if the newly-constructed object
> was valid, or have a separate post-construction initialization step
> which could fail.

It's not just because of exceptions. In C++ virtual method calls in a
constructor for a class A will always call the methods of class A even
if the object being constructed is actually of a subclass B because
the B part of the object isn't initialised when the A constructor is
called. There may be a better way to do this since I last used C++ but
as I remember it the two-phase pattern was a recommended way to
implement polymorphic behaviour during initialisation.


Oscar


From roy at panix.com  Fri May 10 10:37:37 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 10 May 2013 10:37:37 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1527.1368188358.3114.python-list@python.org>
	<roy-F6FC44.10011410052013@news.panix.com>
	<mailman.1530.1368196163.3114.python-list@python.org>
Message-ID: <roy-0C2D3D.10373710052013@news.panix.com>

In article <mailman.1530.1368196163.3114.python-list at python.org>,
 Oscar Benjamin <oscar.j.benjamin at gmail.com> wrote:

> It's not just because of exceptions. In C++ virtual method calls in a
> constructor for a class A will always call the methods of class A even
> if the object being constructed is actually of a subclass B because
> the B part of the object isn't initialised when the A constructor is
> called. There may be a better way to do this since I last used C++ but
> as I remember it the two-phase pattern was a recommended way to
> implement polymorphic behaviour during initialisation.

Mind.  Blown.

One of the things I love (FSVO love) about C++ is that no matter how 
much I learn, there's always whole new areas of wonderment to explore 
behind doors I didn't even know existed.

Thank you.

I suppose, if I had a class like this, I would write a factory function 
which called the constructor and post-construction initializer.  And 
then I would make the constructor protected.


From rosuav at gmail.com  Fri May 10 10:46:56 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 11 May 2013 00:46:56 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <roy-0C2D3D.10373710052013@news.panix.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1527.1368188358.3114.python-list@python.org>
	<roy-F6FC44.10011410052013@news.panix.com>
	<mailman.1530.1368196163.3114.python-list@python.org>
	<roy-0C2D3D.10373710052013@news.panix.com>
Message-ID: <CAPTjJmqzdXcAOBX_pSKqpsK3e-KxhFa2oP0LWkODs2ggr+hv2w@mail.gmail.com>

On Sat, May 11, 2013 at 12:37 AM, Roy Smith <roy at panix.com> wrote:
> I suppose, if I had a class like this, I would write a factory function
> which called the constructor and post-construction initializer.  And
> then I would make the constructor protected.

That sounds like a reasonable plan, with the possible exception of
protected. Since meeting Python, I've stopped using private and
protected anywhere.

ChrisA


From roy at panix.com  Fri May 10 10:54:54 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 10 May 2013 10:54:54 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1527.1368188358.3114.python-list@python.org>
	<roy-F6FC44.10011410052013@news.panix.com>
	<mailman.1530.1368196163.3114.python-list@python.org>
	<roy-0C2D3D.10373710052013@news.panix.com>
	<mailman.1531.1368197225.3114.python-list@python.org>
Message-ID: <roy-E4B847.10545410052013@news.panix.com>

In article <mailman.1531.1368197225.3114.python-list at python.org>,
 Chris Angelico <rosuav at gmail.com> wrote:

> On Sat, May 11, 2013 at 12:37 AM, Roy Smith <roy at panix.com> wrote:
> > I suppose, if I had a class like this, I would write a factory function
> > which called the constructor and post-construction initializer.  And
> > then I would make the constructor protected.
> 
> That sounds like a reasonable plan, with the possible exception of
> protected. Since meeting Python, I've stopped using private and
> protected anywhere.
> 
> ChrisA

Each language has its own set of best practices.  Trying to write C++ 
code using Python patterns is as bad as trying to write Python code 
using C++ patterns.


From rosuav at gmail.com  Fri May 10 11:09:04 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 11 May 2013 01:09:04 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <roy-E4B847.10545410052013@news.panix.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1527.1368188358.3114.python-list@python.org>
	<roy-F6FC44.10011410052013@news.panix.com>
	<mailman.1530.1368196163.3114.python-list@python.org>
	<roy-0C2D3D.10373710052013@news.panix.com>
	<mailman.1531.1368197225.3114.python-list@python.org>
	<roy-E4B847.10545410052013@news.panix.com>
Message-ID: <CAPTjJmo+H_EQGNK8jKe=vJmC9F0o+f4b3KNocyEvuer+Dj9w9Q@mail.gmail.com>

On Sat, May 11, 2013 at 12:54 AM, Roy Smith <roy at panix.com> wrote:
> In article <mailman.1531.1368197225.3114.python-list at python.org>,
>  Chris Angelico <rosuav at gmail.com> wrote:
>
>> On Sat, May 11, 2013 at 12:37 AM, Roy Smith <roy at panix.com> wrote:
>> > I suppose, if I had a class like this, I would write a factory function
>> > which called the constructor and post-construction initializer.  And
>> > then I would make the constructor protected.
>>
>> That sounds like a reasonable plan, with the possible exception of
>> protected. Since meeting Python, I've stopped using private and
>> protected anywhere.
>>
>> ChrisA
>
> Each language has its own set of best practices.  Trying to write C++
> code using Python patterns is as bad as trying to write Python code
> using C++ patterns.

Agreed, in generality. But what is actually gained by hiding data from
yourself? Compare:

class Foo
{
    int asdf;
public:
    Foo(int _asdf):asdf(_asdf) {}
    int get_asdf() {return asdf;}
    void set_asdf(int _asdf) {asdf=_asdf;}
    void frob() {printf("Hi, I am %d\n",asdf);}
};

struct Foo
{
    int asdf;
    Foo(int _asdf):asdf(_asdf) {}
    void frob() {printf("Hi, I am %d\n",asdf);}
};

Is there anything worse about the second one? Oh, and by logical
extension, here's something that doesn't (AFAIK) work in C++, but does
in another language that's syntactically similar:

class Foo(int asdf)
{
    void frob() {write("Hi, I am %d\n",asdf);}
}

Now that's brevity. Why bother saying what's patently obvious? (Pike's
"class" keyword is like C++'s "struct", members are public by
default.)

ChrisA


From roy at panix.com  Fri May 10 11:21:33 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 10 May 2013 11:21:33 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1527.1368188358.3114.python-list@python.org>
	<roy-F6FC44.10011410052013@news.panix.com>
	<mailman.1530.1368196163.3114.python-list@python.org>
	<roy-0C2D3D.10373710052013@news.panix.com>
	<mailman.1531.1368197225.3114.python-list@python.org>
	<roy-E4B847.10545410052013@news.panix.com>
	<mailman.1532.1368198547.3114.python-list@python.org>
Message-ID: <roy-3A4FCB.11213310052013@news.panix.com>

In article <mailman.1532.1368198547.3114.python-list at python.org>,
 Chris Angelico <rosuav at gmail.com> wrote:

> > Each language has its own set of best practices.  Trying to write C++
> > code using Python patterns is as bad as trying to write Python code
> > using C++ patterns.
> 
> Agreed, in generality. But what is actually gained by hiding data from
> yourself? 

You're not hiding it from yourself.  You're hiding it from the other 
people who are using your code and may not understand all the subtle 
gotchas as well as you do.

In the calling-virtual-methods-in-the-constructor case we're talking 
about here, constructing an object by calling B() without immediately 
following it up with a call to B::PostInit() is dangerous.  If you 
document that you shouldn't do that, but allow it anyway, people will do 
it.  Better to disallow it completely.  People will bitch when their 
code doesn't compile, but that's better than compiling and running and 
producing the wrong results.

You solve this problem in Python by simply having the constructor do the 
right thing.


From rosuav at gmail.com  Fri May 10 11:44:31 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 11 May 2013 01:44:31 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <roy-3A4FCB.11213310052013@news.panix.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1527.1368188358.3114.python-list@python.org>
	<roy-F6FC44.10011410052013@news.panix.com>
	<mailman.1530.1368196163.3114.python-list@python.org>
	<roy-0C2D3D.10373710052013@news.panix.com>
	<mailman.1531.1368197225.3114.python-list@python.org>
	<roy-E4B847.10545410052013@news.panix.com>
	<mailman.1532.1368198547.3114.python-list@python.org>
	<roy-3A4FCB.11213310052013@news.panix.com>
Message-ID: <CAPTjJmpwgMBSMDdjYr2aDaQCb+AxWW7ezgfxWujXPCtQ=OCYRw@mail.gmail.com>

On Sat, May 11, 2013 at 1:21 AM, Roy Smith <roy at panix.com> wrote:
> In article <mailman.1532.1368198547.3114.python-list at python.org>,
>  Chris Angelico <rosuav at gmail.com> wrote:
>>
>> Agreed, in generality. But what is actually gained by hiding data from
>> yourself?
>
> You're not hiding it from yourself.  You're hiding it from the other
> people who are using your code and may not understand all the subtle
> gotchas as well as you do.

True. And on looking over my code, I find that there are a few cases
where I've used private members: I have a buffer class that acts
pretty much like a non-refcounted string, and it declares a private
copy constructor to prevent accidental misuse. But it's the exception,
not the rule. My main point isn't about the cases where you actually
want to prevent access, but the all-too-common case where the member
itself is private and there are two public methods to get and set it.
Massive boilerplate. Completely unnecessary in 99%+ of cases.

ChrisA


From robert.kern at gmail.com  Fri May 10 11:33:09 2013
From: robert.kern at gmail.com (Robert Kern)
Date: Fri, 10 May 2013 16:33:09 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <roy-F6FC44.10011410052013@news.panix.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1527.1368188358.3114.python-list@python.org>
	<roy-F6FC44.10011410052013@news.panix.com>
Message-ID: <kmj3vh$jv$1@ger.gmane.org>

On 2013-05-10 15:01, Roy Smith wrote:
> In article <mailman.1527.1368188358.3114.python-list at python.org>,
>   Robert Kern <robert.kern at gmail.com> wrote:
>
>> I'd be curious to see in-the-wild instances of the anti-pattern that
>> you are talking about, then. I think everyone agrees that entirely
>> unmotivated "enable" methods should be avoided, but I have my doubts
>> that they come up very often.
>
> As I mentioned earlier in this thread, this was a common pattern in the
> early days of C++, when exceptions were a new concept and handled poorly
> by many compilers (and, for that matter, programmers).
>
> There was a school of thought that constructors should never be able to
> fail (because the only way for a constructor to fail is to throw an
> exception).  The pattern was to always have the constructor succeed, and
> then either have a way to check to see if the newly-constructed object
> was valid, or have a separate post-construction initialization step
> which could fail.
>
> See, for example, the isValid() and Exists() calls for RogueWave's
> RWFile class (http://tinyurl.com/c8kv26g).  And also,
> http://tinyurl.com/cgs6clx.
>
> Even today, there are C++ implementations which do not use exceptions.
> Some are for use in embedded or real-time systems where things need to
> be strictly time-bound and/or memory-bound.  Others are for historical
> reasons (http://tinyurl.com/6hn4zo).
>
> Once people were used to writing "can't fail" constructors in C++, they
> often continued using that pattern in other languages, where the
> underlying reasons no longer made sense.  Quite possibly, they never
> even knew the underlying reasons; they were taught, "Constructors must
> never fail", and assumed it was a universal rule.

Right, this is one of the "bad reasons" I talk about later in my message. The 
authors had a reason in their mind for doing it (they thought it was a universal 
rule); it was just a bad one. It's more useful to talk about why people thought 
they should follow that pattern than to just say "there is no reason to do this".

> This, BTW, is one of my biggest beefs with the classic Gang Of Four
> pattern book.  It presents a bunch of patterns as being universally
> applicable, when in reality many (if not most) of them are highly C++
> specific.
>
> BTW, whenever I read things like, "I think everyone agrees", I
> automatically assume what the writer really meant was, "I, and all the
> people who agree with me, think".

Hah! Fair enough. I actually meant it to emphasize that I thought that Steven 
was overly reducing his statements to something that was trivially true, 
sacrificing content for validity. I will suggest that your interpretation of 
that phrase is more appropriate when the speaker is proposing something of their 
own rather than (partially) conceding a point. The exaggeration is only 
self-aggrandizing in the former case.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco



From dreamingforward at gmail.com  Fri May 10 22:43:52 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Fri, 10 May 2013 19:43:52 -0700
Subject: object.enable() anti-pattern
In-Reply-To: <518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<roy-8428A6.09074209052013@news.panix.com>
	<518be931$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1501.1368124461.3114.python-list@python.org>
	<518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<roy-6D8B98.23095509052013@news.panix.com>
	<518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<Hm0jt.6$I26.5@newsfe26.iad>
	<518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAMjeLr9i+7semBMPhSHLVu=5x-AYAEoJV_UnzVx8a4tMPZs5Cg@mail.gmail.com>

>>>>>> There is no sensible use-case for creating a file OBJECT unless it
>>>>>> initially wraps an open file pointer.
>>
>>> So far the only counter-examples given aren't counter-examples ...
>>
>> Well, sure, if you discount operations like "create this file" and
>> queries like "could I delete this file if I wanted to?" [0] as methods
>> of the file system rather than of a hypothetical file object.
>>
>> What about a distributed system?  Suppose I want to create a file object
>> in one place, and send that object to the another place for the file to
>> be read from or written to [1]?  Suppose that for security reasons, I
>> have to do it that way, because the first place can only create the
>> objects, and the second place can only access the underly file contents
>> through an existing object?
>
> Unless you have re-implemented the file I/O system, it doesn't matter. If
> your file objects are based on C I/O, then even if the first server
> cannot read or write to the files it still creates file objects in an
> open state, because that is how C works.
>
> Or maybe the first server only creates some sort of proxy to the real
> underlying file object. Or maybe you're re-implemented the I/O system,
> and aren't following C's design. Since you're just making this up as a
> thought experiment, anything is possible.
>
> But either way, that's fine. You've found an object where it does make
> sense to have an explicit "make it go" method: first one entity has
> permission to construct the object, but not to open the underlying file.
> Another entity has permission to open the underlying file, but not to
> create the object. I have no idea whether this is a reasonable security
> design or not, it actually sounds a bit rubbish to me but what do I know?
> So let's treat it as a reasonable design.
>
> As I've said, repeatedly, that's not what I'm talking about.
>
> When you DON'T have useful things that can be done with the object before
> calling "enable", then it is an anti-pattern to require a separate call
> to "enable" method, and the enable functionality should be moved into the
> object constructor. If you DO have useful things that can be done, like
> pass the object to another entity, for security, then that's a whole
> 'nuther story.

You're missing one other case:  if there's useful things that can be
checked before calling enable().  Remember, on multi-user and/or
multi-processing systems, there could be contention for a slow
resource.  If you automatically open a file for write, you're
preventing everyone else from writing and potentially reading it.  So
there is something useful: did that file exist?  Is that resource
available for writing?

Prior to such hi-level languages like Python and reliable hardware,
such fine-grained control was important and vital.   Now it can
probably be relegated to special OS libraries.

Mark

> Really, what I'm describing is *normal* behaviour for most objects. We
> don't usually design APIs like this:
>
> n = int("42")
> n.enable()
> m = n + 1
> m.enable()
> x = m*2 + n*3
> print x - 1  # oops, raises because I forgot to call x.enable()

Again, you only do that for shared resources.  In this case, memory
would have to be a (protected) shared resources, but the OS manages
memory allocation, so it's not an issue.

Mark

> That's a rubbish API, and for simple data-like objects, we all agree it
> is a rubbish API. So why accept the same rubbish API just because the
> object is more complicated?

I think I just told you, but let me know ..... :)

> For my next controversial opinion, I'm going to argue that we should do
> arithmetic using numbers rather than by inserting lists inside other
> lists:

Try arguing that we should have a common message-passing syntax.

> # Do this:
>
> count = 0
> count += 1
>
> # Not this:
>
> count = []
> count.insert(0, [])

That's actually what they do in "set theory", believe it or not.

MarkJ
Tacoma, Washington


From nobody at nowhere.com  Fri May 10 12:59:26 2013
From: nobody at nowhere.com (Nobody)
Date: Fri, 10 May 2013 17:59:26 +0100
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
Message-ID: <pan.2013.05.10.16.59.31.512000@nowhere.com>

On Thu, 09 May 2013 05:23:59 +0000, Steven D'Aprano wrote:

> There is no sensible use-case for creating a file without opening it. 
> What would be the point? Any subsequent calls to just about any method 
> will fail. Since you have to open the file after creating the file object 
> anyway, why make them two different calls?

As a counterpoint, some OSes (e.g. Plan 9) allow you to get a "handle" to
a file without opening it. This can then be used for deleting, renaming or
stat()-type operations without either the risk of race conditions (if
another process renames files between operations, the operations may
be performed on different files) or the side-effects of actually opening
the file (particularly for device files, e.g. opening a tape drive may
rewind the tape).

Python's file model doesn't allow for this, so there isn't really anything
meaningful that you can do on a file object which isn't open (although
these actually exist; any file object on which the .close() method has
been called will be in this state).

However: there are situations where it is useful to be able to separate
the simple task of creating an object from more invasive actions such as
system calls. Particularly in multi-threaded or real-time code (although
the latter is a non-starter in Python for many other reasons).



From roy at panix.com  Fri May 10 13:32:50 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 10 May 2013 13:32:50 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<pan.2013.05.10.16.59.31.512000@nowhere.com>
Message-ID: <roy-A06962.13325010052013@news.panix.com>

In article <pan.2013.05.10.16.59.31.512000 at nowhere.com>,
 Nobody <nobody at nowhere.com> wrote:

> However: there are situations where it is useful to be able to separate
> the simple task of creating an object from more invasive actions such as
> system calls. Particularly in multi-threaded or real-time code (although
> the latter is a non-starter in Python for many other reasons).

Sure.  I can serialize a path name.  I can't serialize an open file 
descriptor.


From steve+comp.lang.python at pearwood.info  Sat May 11 03:05:00 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 11 May 2013 07:05:00 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<Z1Eit.289$oB7.283@newsfe02.iad>
	<518b32ef$0$11120$c3e8da3@news.astraweb.com>
	<pan.2013.05.10.16.59.31.512000@nowhere.com>
Message-ID: <518ded9c$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 10 May 2013 17:59:26 +0100, Nobody wrote:

> On Thu, 09 May 2013 05:23:59 +0000, Steven D'Aprano wrote:
> 
>> There is no sensible use-case for creating a file without opening it.
>> What would be the point? Any subsequent calls to just about any method
>> will fail. Since you have to open the file after creating the file
>> object anyway, why make them two different calls?
> 
> As a counterpoint, some OSes (e.g. Plan 9) allow you to get a "handle"
> to a file without opening it. This can then be used for deleting,
> renaming or stat()-type operations without either the risk of race
> conditions (if another process renames files between operations, the
> operations may be performed on different files) or the side-effects of
> actually opening the file (particularly for device files, e.g. opening a
> tape drive may rewind the tape).

Ah, now that's a fantastic counter-example. But I think that says more 
about the primitiveness of the Unix file model than of the idea of 
temporal coupling.


> Python's file model doesn't allow for this, so there isn't really
> anything meaningful that you can do on a file object which isn't open
> (although these actually exist; any file object on which the .close()
> method has been called will be in this state).

Absolutely correct, and I'm amazed it's taken this long for anyone to 
point this out :-)



-- 
Steven


From dreamingforward at gmail.com  Wed May  8 22:53:36 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Wed, 8 May 2013 19:53:36 -0700
Subject: object.enable() anti-pattern
In-Reply-To: <518a123c$0$11094$c3e8da3@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
Message-ID: <CAMjeLr_-Om2UpBg7+2Eqgp3A7fHD1UqJ9TMDURc5Y6sejSHRWA@mail.gmail.com>

> I'm looking for some help in finding a term, it's not Python-specific but
> does apply to some Python code.
>
> This is an anti-pattern to avoid. The idea is that creating a resource
> ought to be the same as "turning it on", or enabling it, or similar. For
> example, we don't do this in Python:

I would call it "user-mediated resource allocation" as distinct from
"object-mediated" resource allocation.
-- 
MarkJ
Tacoma, Washington


From dreamingforward at gmail.com  Wed May  8 22:56:02 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Wed, 8 May 2013 19:56:02 -0700
Subject: object.enable() anti-pattern
In-Reply-To: <CAMjeLr_-Om2UpBg7+2Eqgp3A7fHD1UqJ9TMDURc5Y6sejSHRWA@mail.gmail.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<CAMjeLr_-Om2UpBg7+2Eqgp3A7fHD1UqJ9TMDURc5Y6sejSHRWA@mail.gmail.com>
Message-ID: <CAMjeLr_77oJMxTFMmb+-v10UyT-YWiOwDwLkWTj-T3-gOJ8hCQ@mail.gmail.com>

>> This is an anti-pattern to avoid. The idea is that creating a resource
>> ought to be the same as "turning it on", or enabling it, or similar. For
>> example, we don't do this in Python:
>
> I would call it "user-mediated resource allocation" as distinct from
> "object-mediated" resource allocation.

I should point out, though, it's not really an anti-pattern (coming
form the C community).

-- 
MarkJ
Tacoma, Washington


From wayne at waynewerner.com  Thu May  9 07:08:25 2013
From: wayne at waynewerner.com (Wayne Werner)
Date: Thu, 9 May 2013 06:08:25 -0500 (CDT)
Subject: object.enable() anti-pattern
In-Reply-To: <518a123c$0$11094$c3e8da3@news.astraweb.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
Message-ID: <alpine.DEB.2.02.1305090556440.3322@gilgamesh>



On Wed, 8 May 2013, Steven D'Aprano wrote:

> I'm looking for some help in finding a term, it's not Python-specific but
> does apply to some Python code.
>
> This is an anti-pattern to avoid. The idea is that creating a resource
> ought to be the same as "turning it on", or enabling it, or similar. For
> example, we don't do this in Python:

I'm not entirely sure what the name of it is, but the basic concept is 
that you should never partially create, or create a class that can be in 
an unstable state. Which isn't to say you should prevent invalid input, 
only that with every valid input or single operation (including 
construction) your class should be valid.


Ah, that's it - the problem is that it introduces /Temporal Coupling/ to 
one's code: http://blog.ploeh.dk/2011/05/24/DesignSmellTemporalCoupling/

You don't ever want a class that has functions that need to be called in a 
certain order to *not* crash. That's fine if you have to call them in a 
certain sequence in order to get the correct data - that's what 
programming is all about, after all. But if you provide me a class with a 
constructor you better make sure that when I do this:

     thing = YourSuperAwesomeClass()
     thing.do_stuff()

that I don't get some horrid stack trace ending with

     InvalidStateError: initialize() needs to be called before do_stuff()

Or something worse.


HTH,
Wayne

p.s. I'm interested in reading whatever is evenually written on the topic


From steve+comp.lang.python at pearwood.info  Thu May  9 07:51:22 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 11:51:22 GMT
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
Message-ID: <518b8db9$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Thu, 09 May 2013 06:08:25 -0500, Wayne Werner wrote:

> Ah, that's it - the problem is that it introduces /Temporal Coupling/ to
> one's code: http://blog.ploeh.dk/2011/05/24/DesignSmellTemporalCoupling/

Good catch!

That's not the blog post I read, but that's the same concept. "Temporal 
Coupling" -- yes, that is an excellent description of the problem.


> You don't ever want a class that has functions that need to be called in
> a certain order to *not* crash. That's fine if you have to call them in
> a certain sequence in order to get the correct data - that's what
> programming is all about, after all. But if you provide me a class with
> a constructor you better make sure that when I do this:
> 
>      thing = YourSuperAwesomeClass()
>      thing.do_stuff()
> 
> that I don't get some horrid stack trace ending with
> 
>      InvalidStateError: initialize() needs to be called before
>      do_stuff()
> 
> Or something worse.

Exactly.


Thank you Wayne, that's a great help.



-- 
Steven


From greg.ewing at canterbury.ac.nz  Thu May  9 19:43:42 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Fri, 10 May 2013 11:43:42 +1200
Subject: object.enable() anti-pattern
In-Reply-To: <mailman.1490.1368098298.3114.python-list@python.org>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
Message-ID: <av2qleF58afU1@mid.individual.net>

Wayne Werner wrote:
> You don't ever want a class that has functions that need to be called in 
> a certain order to *not* crash.

That seems like an overly broad statement. What
do you think the following should do?

    f = open("myfile.dat")
    f.close()
    data = f.read()

-- 
Greg


From knomenet at gmail.com  Thu May  9 20:18:39 2013
From: knomenet at gmail.com (Michael Speer)
Date: Thu, 9 May 2013 20:18:39 -0400
Subject: object.enable() anti-pattern
In-Reply-To: <av2qleF58afU1@mid.individual.net>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
	<av2qleF58afU1@mid.individual.net>
Message-ID: <CABpSurDRJWWA244maz4ND7vUHRR4NmdYd_hBh4JrwK5+T1kSvQ@mail.gmail.com>

By his reasoning it simply shouldn't exist. Instead you would access the
information only like this:

with open("myfile.dat") as f:
  data = f.read()

Which is my preferred way to work with resources requiring cleanup in
python anyways, as it ensures I have the least chance of messing things up,
and that all of my resources are disposed of properly during the unwind.
It's a hell of a lot cleaner than remembering to call the appropriate
cleanup functions at every callsite, and the resultant values can never be
in a bad state ( at least due to programmer function-ordering fault,
underlying file i/o errors and things can still cause errors, but not due
to API mis-usage ).

Python 3's multiple-with-statement-target syntax was backported to 2.7 as
well, flattening the deep nests of with statements otherwise needed to
implement this pattern
    http://docs.python.org/dev/whatsnew/2.7.html#other-language-changes

On Thu, May 9, 2013 at 7:43 PM, Gregory Ewing
<greg.ewing at canterbury.ac.nz>wrote:

> Wayne Werner wrote:
>
>> You don't ever want a class that has functions that need to be called in
>> a certain order to *not* crash.
>>
>
> That seems like an overly broad statement. What
> do you think the following should do?
>
>    f = open("myfile.dat")
>    f.close()
>    data = f.read()
>
>
> --
> Greg
> --
> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>
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From roy at panix.com  Thu May  9 20:50:16 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 09 May 2013 20:50:16 -0400
Subject: object.enable() anti-pattern
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
	<av2qleF58afU1@mid.individual.net>
	<mailman.1514.1368145123.3114.python-list@python.org>
Message-ID: <roy-FA6CCF.20501509052013@news.panix.com>

In article <mailman.1514.1368145123.3114.python-list at python.org>,
 Michael Speer <knomenet at gmail.com> wrote:

> By his reasoning it simply shouldn't exist. Instead you would access the
> information only like this:
> 
> with open("myfile.dat") as f:
>   data = f.read()

The problem with things like file objects is they model external 
real-world entities, which have externally-imposed real-world behaviors.

f.close() can fail, most commonly because some buffered output couldn't 
be written when being flushed as part of the close().  Sometimes it's 
important to find out about that.


From wayne at waynewerner.com  Sun May 12 13:14:33 2013
From: wayne at waynewerner.com (Wayne Werner)
Date: Sun, 12 May 2013 12:14:33 -0500 (CDT)
Subject: object.enable() anti-pattern
In-Reply-To: <av2qleF58afU1@mid.individual.net>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
	<av2qleF58afU1@mid.individual.net>
Message-ID: <alpine.DEB.2.02.1305121214180.3322@gilgamesh>

On Fri, 10 May 2013, Gregory Ewing wrote:

> Wayne Werner wrote:
>> You don't ever want a class that has functions that need to be called in a 
>> certain order to *not* crash.
>
> That seems like an overly broad statement. What
> do you think the following should do?
>
>   f = open("myfile.dat")
>   f.close()
>   data = f.read()

To clarify - you don't want a class that has functions that need to be 
called in a certain order with *valid input* in order to not crash.

Exactly what does happen - a ValueError is raised because you're(*) 
passing self into the file.read() function, and that input is invalid 
input - specifically:

     ValueError: I/O operation on closed file

*where you actually means python, because when you call 
`your_instance.method()`, it works effectively like a call to 
`YourClass.method(your_instance)`

-W


From tjreedy at udel.edu  Sun May 12 16:03:39 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 12 May 2013 16:03:39 -0400
Subject: object.enable() anti-pattern
In-Reply-To: <alpine.DEB.2.02.1305121214180.3322@gilgamesh>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
	<av2qleF58afU1@mid.individual.net>
	<alpine.DEB.2.02.1305121214180.3322@gilgamesh>
Message-ID: <kmosie$mp2$1@ger.gmane.org>

On 5/12/2013 1:14 PM, Wayne Werner wrote:
> On Fri, 10 May 2013, Gregory Ewing wrote:
>
>> Wayne Werner wrote:
>>> You don't ever want a class that has functions that need to be called
>>> in a certain order to *not* crash.
>>
>> That seems like an overly broad statement. What
>> do you think the following should do?
>>
>>   f = open("myfile.dat")
>>   f.close()
>>   data = f.read()
>
> To clarify - you don't want a class that has functions that need to be
> called in a certain order with *valid input* in order to not crash.
>
> Exactly what does happen - a ValueError is raised because you're(*)
> passing self into the file.read() function, and that input is invalid
> input - specifically:
>
>      ValueError: I/O operation on closed file
>
> *where you actually means python, because when you call
> `your_instance.method()`, it works effectively like a call to
> `YourClass.method(your_instance)`

The new idiom
with open("myfile.dat") as f:
     data = f.read()

partially encapsulates operations on the opened file before the 
automatic close. It is true however, that after the with statement, f in 
still uselessly bound to the closed file. (Well, you can check the mode, 
encoding, and other attributes, so not totally useless.) To completely 
encapsulate, one can end the block with 'del f'. I checked and this 
works. Since the external 'as x' name binding is optional, an internal 
reference to the context manager (the io.xxx instance) is kept in order 
to call the __exit__ method, and that is not affected by deleting the 
optional visible binding.

tjr




From greg.ewing at canterbury.ac.nz  Sun May 12 19:18:10 2013
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Mon, 13 May 2013 11:18:10 +1200
Subject: object.enable() anti-pattern
In-Reply-To: <alpine.DEB.2.02.1305121214180.3322@gilgamesh>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
	<av2qleF58afU1@mid.individual.net>
	<alpine.DEB.2.02.1305121214180.3322@gilgamesh>
Message-ID: <51902332.8090301@canterbury.ac.nz>

Wayne Werner wrote:
> On Fri, 10 May 2013, Gregory Ewing wrote:
> 
>>   f = open("myfile.dat")
>>   f.close()
>>   data = f.read()
> 
> To clarify - you don't want a class that has functions that need to be 
> called in a certain order with *valid input* in order to not crash.
> 
> Exactly what does happen - a ValueError is raised because you're(*) 
> passing self into the file.read() function, and that input is invalid

The same argument can be applied to:

    foo = Foo()
    foo.do_something()
    foo.enable() # should have done this first

You're passing an invalid input to Foo.do_something,
namely a Foo that hasn't been enabled yet.

-- 
Greg


From fabiosantosart at gmail.com  Mon May 13 02:32:36 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 13 May 2013 07:32:36 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <51902332.8090301@canterbury.ac.nz>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
	<av2qleF58afU1@mid.individual.net>
	<alpine.DEB.2.02.1305121214180.3322@gilgamesh>
	<51902332.8090301@canterbury.ac.nz>
Message-ID: <CAA=1kxTuXtWkSYhbMNab8x9k2VMThuLiVWT5L4JFfbBaTEGN6A@mail.gmail.com>

On 13 May 2013 00:22, "Greg Ewing" <greg.ewing at canterbury.ac.nz> wrote:
>
> Wayne Werner wrote:
>>
>> On Fri, 10 May 2013, Gregory Ewing wrote:
>>
>>>   f = open("myfile.dat")
>>>   f.close()
>>>   data = f.read()
>>
>>
>> To clarify - you don't want a class that has functions that need to be
called in a certain order with *valid input* in order to not crash.
>>
>> Exactly what does happen - a ValueError is raised because you're(*)
passing self into the file.read() function, and that input is invalid
>
>
> The same argument can be applied to:
>
>    foo = Foo()
>    foo.do_something()
>    foo.enable() # should have done this first
>
> You're passing an invalid input to Foo.do_something,
> namely a Foo that hasn't been enabled yet.
>
>
> --
> Greg
> --
> http://mail.python.org/mailman/listinfo/python-list

I don't think you can really count that as invalid input in OOP terms.
After all in most languages `self` / `this` / whatever is not an argument
to every method.
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From rosuav at gmail.com  Mon May 13 03:36:41 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 13 May 2013 17:36:41 +1000
Subject: object.enable() anti-pattern
In-Reply-To: <CAA=1kxTuXtWkSYhbMNab8x9k2VMThuLiVWT5L4JFfbBaTEGN6A@mail.gmail.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
	<av2qleF58afU1@mid.individual.net>
	<alpine.DEB.2.02.1305121214180.3322@gilgamesh>
	<51902332.8090301@canterbury.ac.nz>
	<CAA=1kxTuXtWkSYhbMNab8x9k2VMThuLiVWT5L4JFfbBaTEGN6A@mail.gmail.com>
Message-ID: <CAPTjJmr5-heu3EMp_4Q4OL8K_+OyPAcseuc0xUiPTB9h988NXA@mail.gmail.com>

On Mon, May 13, 2013 at 4:32 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
>
> On 13 May 2013 00:22, "Greg Ewing" <greg.ewing at canterbury.ac.nz> wrote:
>> The same argument can be applied to:
>>
>>    foo = Foo()
>>    foo.do_something()
>>    foo.enable() # should have done this first
>>
>> You're passing an invalid input to Foo.do_something,
>> namely a Foo that hasn't been enabled yet.
>
> I don't think you can really count that as invalid input in OOP terms. After
> all in most languages `self` / `this` / whatever is not an argument to every
> method.

Yes, it is; it's just often implicit. C++ lets you poke around with
the internals, and it's pretty clear that 'this' is an argument. (See
for instance what happens with the gcc 'format' attribute - I can't
find a convenient docs page, but it's been mentioned on SO [1] and can
be easily verified.) EMCAScript lets you call any function with any
'this' by using the .call() or .apply() methods - which, in my
extremely not-humble opinionated opinion, is bad design (closures work
implicitly, but the 'this' pointer doesn't??). Python turns an
attribute lookup on an instance into an attribute lookup on the class
plus a currying. One way or another, the bit-before-the-dot is an
argument to the function.

[1] http://stackoverflow.com/questions/11621043/how-should-i-properly-use-attribute-format-printf-x-y-inside-a-class

ChrisA


From fabiosantosart at gmail.com  Mon May 13 04:09:37 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 13 May 2013 09:09:37 +0100
Subject: object.enable() anti-pattern
In-Reply-To: <CAPTjJmr5-heu3EMp_4Q4OL8K_+OyPAcseuc0xUiPTB9h988NXA@mail.gmail.com>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
	<av2qleF58afU1@mid.individual.net>
	<alpine.DEB.2.02.1305121214180.3322@gilgamesh>
	<51902332.8090301@canterbury.ac.nz>
	<CAA=1kxTuXtWkSYhbMNab8x9k2VMThuLiVWT5L4JFfbBaTEGN6A@mail.gmail.com>
	<CAPTjJmr5-heu3EMp_4Q4OL8K_+OyPAcseuc0xUiPTB9h988NXA@mail.gmail.com>
Message-ID: <CAA=1kxSaBqazdix0qHgJj4DQ=MP01TTz39fa39rLR-_pT10BUA@mail.gmail.com>

On 13 May 2013 08:40, "Chris Angelico" <rosuav at gmail.com> wrote:
>
> On Mon, May 13, 2013 at 4:32 PM, F?bio Santos <fabiosantosart at gmail.com>
wrote:
> >
> > On 13 May 2013 00:22, "Greg Ewing" <greg.ewing at canterbury.ac.nz> wrote:
> >> The same argument can be applied to:
> >>
> >>    foo = Foo()
> >>    foo.do_something()
> >>    foo.enable() # should have done this first
> >>
> >> You're passing an invalid input to Foo.do_something,
> >> namely a Foo that hasn't been enabled yet.
> >
> > I don't think you can really count that as invalid input in OOP terms.
After
> > all in most languages `self` / `this` / whatever is not an argument to
every
> > method.
>
> Yes, it is; it's just often implicit. C++ lets you poke around with
> the internals, and it's pretty clear that 'this' is an argument. (See
> for instance what happens with the gcc 'format' attribute - I can't
> find a convenient docs page, but it's been mentioned on SO [1] and can
> be easily verified.) EMCAScript lets you call any function with any
> 'this' by using the .call() or .apply() methods - which, in my
> extremely not-humble opinionated opinion, is bad design (closures work
> implicitly, but the 'this' pointer doesn't??). Python turns an
> attribute lookup on an instance into an attribute lookup on the class
> plus a currying. One way or another, the bit-before-the-dot is an
> argument to the function.
>
> [1]
http://stackoverflow.com/questions/11621043/how-should-i-properly-use-attribute-format-printf-x-y-inside-a-class
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list

I know ECMAScript does that. It would be nice to be able to pass an
instance method as a callback argument without using `.bind(theInstance)`.

At any rate, exposed or not, that is all still internals. Exposing the
ability to set the ` this ` as an argument is, I think, a functional
feature (map(str.strip, file) is a good example)

That said, I didn't know c++ did that, but it makes sense with what I read
somewhere about c++ starting out as a transcompiler-to-c-based language.
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From wayne at waynewerner.com  Mon May 13 09:15:07 2013
From: wayne at waynewerner.com (Wayne Werner)
Date: Mon, 13 May 2013 08:15:07 -0500 (CDT)
Subject: object.enable() anti-pattern
In-Reply-To: <51902332.8090301@canterbury.ac.nz>
References: <518a123c$0$11094$c3e8da3@news.astraweb.com>
	<mailman.1490.1368098298.3114.python-list@python.org>
	<av2qleF58afU1@mid.individual.net>
	<alpine.DEB.2.02.1305121214180.3322@gilgamesh>
	<51902332.8090301@canterbury.ac.nz>
Message-ID: <alpine.DEB.2.02.1305130725500.3322@gilgamesh>

On Mon, 13 May 2013, Greg Ewing wrote:

> Wayne Werner wrote:
>> On Fri, 10 May 2013, Gregory Ewing wrote:
>>
>>>   f = open("myfile.dat")
>>>   f.close()
>>>   data = f.read()
>> 
>> To clarify - you don't want a class that has functions that need to be 
>> called in a certain order with *valid input* in order to not crash.
>> 
>> Exactly what does happen - a ValueError is raised because you're(*) passing 
>> self into the file.read() function, and that input is invalid
>
> The same argument can be applied to:
>
>   foo = Foo()
>   foo.do_something()
>   foo.enable() # should have done this first
>
> You're passing an invalid input to Foo.do_something,
> namely a Foo that hasn't been enabled yet.

That is the crux of the argument - as designer of the class *you* need to 
ensure that when your constructor is done, your class is in a stable 
state. And that every other state transition (with valid input) results in 
your class then being in a stable state.


If anything, the stronger argument is that `file.close()` is not a well 
designed function because it leaves your object in an unstable state.

Which I would be inclined to agree with, but I couldn't give you the 
answer for what makes it better. Because the answer is the best one you 
can get in computer science: It depends.


The reason that it depends, is because it depends on what you want to do. 
Do you want a program that seems purely functional? Do you want a program 
that's easy to maintain? Do you want a program that more accurately models 
the "real world"?

Personally, I think the file object API in Python is about as good as it 
can get - but that's because it's working with "physical" things (i.e. 
files - bits on a platter, or flash/SSD drive...) which necessarily have a 
temporal nature. And it's much less badness to blow up on a call to `read` 
than it is to remove the `read` function and die with a NameError when the 
underlying file is in a closed state.


At least in my opinion ;)
-W


From breamoreboy at yahoo.co.uk  Wed May  8 05:39:50 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 08 May 2013 10:39:50 +0100
Subject: cello library
Message-ID: <kmd6h3$uuj$1@ger.gmane.org>

Hi folks,

I thought some of you might find this interesting http://libcello.org/

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From rosuav at gmail.com  Wed May  8 06:01:56 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 8 May 2013 20:01:56 +1000
Subject: cello library
In-Reply-To: <kmd6h3$uuj$1@ger.gmane.org>
References: <kmd6h3$uuj$1@ger.gmane.org>
Message-ID: <CAPTjJmpq3Ai0cD4BrVFPrH9Bq9vU6cAcphu=BJP3ta_vqbYS8Q@mail.gmail.com>

On Wed, May 8, 2013 at 7:39 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> Hi folks,
>
> I thought some of you might find this interesting [link redacted]

If this is a legit post, can you please elaborate on just _why_ we
would find it interesting? I'm leery of clicking random links like
that without at least some indication. It could be some cool Python
library, or it could be something relating to music, or it could be a
malicious site ready to compromise my browser and your Yahoo account
was compromised to send spam.

ChrisA


From tjreedy at udel.edu  Wed May  8 17:06:31 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Wed, 08 May 2013 17:06:31 -0400
Subject: cello library
In-Reply-To: <CAPTjJmpq3Ai0cD4BrVFPrH9Bq9vU6cAcphu=BJP3ta_vqbYS8Q@mail.gmail.com>
References: <kmd6h3$uuj$1@ger.gmane.org>
	<CAPTjJmpq3Ai0cD4BrVFPrH9Bq9vU6cAcphu=BJP3ta_vqbYS8Q@mail.gmail.com>
Message-ID: <kmeeof$18r$1@ger.gmane.org>

On 5/8/2013 6:01 AM, Chris Angelico wrote:
> On Wed, May 8, 2013 at 7:39 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>> Hi folks,
>>
>> I thought some of you might find this interesting [link redacted]

Unredacted: http://libcello.org/

> If this is a legit post, can you please elaborate on just _why_ we
> would find it interesting? I'm leery of clicking random links like
> that without at least some indication. It could be some cool Python
> library, or it could be something relating to music, or it could be a
> malicious site ready to compromise my browser and your Yahoo account
> was compromised to send spam.

Legitimate request, like some I have made of others. Since I trust Mark:

"Cello is a GNU99 C library which brings higher level programming to C.

         Interfaces allow for structured design
         Duck Typing allows for generic functions
         Exceptions control error handling
         Constructors/Destructors aid memory management
         Syntactic Sugar increases readability
         C Library means excellent performance and integration
...Cello is licensed under BSD3."

Partly inspired by Python, including this:

  /* "with" automatically closes file at end of scope. */
   with (file in open($(File, NULL), "prices.bin", "wb"))) {
...
   }

An interesting question is whether it could be used to convert or 
rewrite Python to C.

__
Terry Jan Reedy




From rosuav at gmail.com  Wed May  8 20:08:24 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 9 May 2013 10:08:24 +1000
Subject: cello library
In-Reply-To: <kmeeof$18r$1@ger.gmane.org>
References: <kmd6h3$uuj$1@ger.gmane.org>
	<CAPTjJmpq3Ai0cD4BrVFPrH9Bq9vU6cAcphu=BJP3ta_vqbYS8Q@mail.gmail.com>
	<kmeeof$18r$1@ger.gmane.org>
Message-ID: <CAPTjJmpWxdeRBXBSkQjiDbngDgUc5XYDrNRwx+6yQb68Bq9pRg@mail.gmail.com>

On Thu, May 9, 2013 at 7:06 AM, Terry Jan Reedy <tjreedy at udel.edu> wrote:
> Legitimate request, like some I have made of others. Since I trust Mark:

It's actually nothing to do with trusting Mark. I've often seen posts
from addresses of people I trust, but with links that I definitely
would not want to click... and Mark posts from Yahoo, which is one of
the common targets of that sort of attack.

Anyway, a little context would have solved the whole thing.

ChrisA


From samjnaa at gmail.com  Wed May  8 07:19:07 2013
From: samjnaa at gmail.com (jamadagni)
Date: Wed, 8 May 2013 04:19:07 -0700 (PDT)
Subject: Help with implementing callback functions using ctypes
Message-ID: <8931a89c-0d00-4c8b-ba19-cf683d8d266d@googlegroups.com>

Hello. I am running Kubuntu Raring with Python 3.3.1. (I mostly don't myself use Py2.) 

I have the below C program spiro.c (obviously a simplified testcase) which I compile to a sharedlib using clang -fPIC -shared -o libspiro.so spiro.c, sudo cp to /usr/lib and am trying to call from a Python script spiro.py using ctypes. However it would seem that the first call to the callback results in a segfault. (The line before the callback is executed.) I tried debugging using gdb but perhaps because of my insufficient knowledge I couldn't find out what is causing the problem. 

I hope some of the kind knowledgeable souls here can help me out:

-- spiro.c

# include <stdbool.h>
# include <stdio.h>

typedef struct _bezctx bezctx ;
struct _bezctx {
	void ( * moveto    ) ( bezctx * bc, double x, double y, bool starts_open_path ) ;
	void ( * lineto    ) ( bezctx * bc, double x, double y ) ;
	void ( * curveto   ) ( bezctx * bc, double c1x, double c1y, double c2x, double c2y, double x, double y ) ;
    void ( * track_seg ) ( bezctx * bc, unsigned int start_node_idx ) ;
} ;

typedef struct {
	double x, y ;
	char ty ;
} spiro_cp ;
 
bool spiro_to_bezier_strict ( const spiro_cp src [], int src_len, bezctx * bc ) {
	for ( int i = 0 ; i < src_len ; ++i ) {
		const spiro_cp * p = &(src[i]) ;
		printf ( "%g %g %c\n", p->x, p->y, p->ty ) ;
		if ( i % 2 == 0 )
			bc -> moveto ( bc, p->x, p->y, i % 3 ) ;
		else
			bc -> lineto ( bc, p->x, p->y ) ;
		bc -> curveto ( bc, 233, 150, 267, 150, 300, 100 ) ;
		bc -> track_seg ( bc, i ) ;
	}
	return src_len % 2 == 0 ;
}

-- spiro.py

from ctypes import *

# incomplete struct definition needed for pointer below
class bezctx ( Structure ) : pass

# pointer to function types for callback
MoveToFnType       = CFUNCTYPE ( None, POINTER ( bezctx ), c_double, c_double, c_bool )
LineToFnType       = CFUNCTYPE ( None, POINTER ( bezctx ), c_double, c_double )
CurveToFnType      = CFUNCTYPE ( None, POINTER ( bezctx ), c_double, c_double, c_double, c_double, c_double, c_double )
TrackSegmentFnType = CFUNCTYPE ( None, POINTER ( bezctx ), c_uint )

# completing the struct definition
bezctx._fields_ = [ ( "moveto"   , MoveToFnType       ), 
                    ( "lineto"   , LineToFnType       ), 
                    ( "curveto"  , CurveToFnType      ), 
                    ( "track_seg", TrackSegmentFnType ) ]

# the python callbacks
def moveTo ( bc, x, y, startsOpenPath ) :
	print ( "moveTo", bc, x, y, startsOpenPath )
def lineTo ( bc, x, y ) :
	print ( "lineTo", bc, x, y )
def curveTo ( bc, c1x, c1y, c2x, c2y, x, y ) :
	print ( "curveTo", bc, c1x, c1y, c2x, c2y, x, y )
def trackSegment ( bc, start_node_idx ) :
	print ( "trackSegment", bc, start_node_idx )

# instance of struct
bc = bezctx ()
bc . moveto    = MoveToFnType       ( moveTo       )
bc . lineto    = LineToFnType       ( lineTo       )
bc . curveto   = CurveToFnType      ( curveTo      )
bc . track_seg = TrackSegmentFnType ( trackSegment )

# another struct
class spiro_cp ( Structure ) :
	_fields_ = [ ( "x", c_double ), ( "y", c_double ), ( "ty", c_char ) ]

# array of struct instances
srclist = [ spiro_cp ( 147, 215, b'o' ), 
            spiro_cp ( 168, 136, b'o' ), 
            spiro_cp ( 294, 184, b'[' ), 
            spiro_cp ( 381, 136, b']' ), 
            spiro_cp ( 445, 204, b'c' ), 
            spiro_cp ( 364, 235, b'c' ), 
            spiro_cp ( 266, 285, b'v' ) ]
src = ( spiro_cp * len ( srclist ) ) ( *srclist )

# open the sharedlib
libspiro = CDLL ( "libspiro.so" )
spiro_to_bezier_strict = libspiro.spiro_to_bezier_strict

# call the C function
spiro_to_bezier_strict ( src, len ( src ), bc )

-- bash session

$ python3 spiro-ctypes.py 
147 215 o
Segmentation fault (core dumped)


From dieter at handshake.de  Thu May  9 01:54:57 2013
From: dieter at handshake.de (dieter)
Date: Thu, 09 May 2013 07:54:57 +0200
Subject: Help with implementing callback functions using ctypes
References: <8931a89c-0d00-4c8b-ba19-cf683d8d266d@googlegroups.com>
Message-ID: <87mws4bsum.fsf@handshake.de>

jamadagni <samjnaa at gmail.com> writes:
> ...
I cannot help you with "ctypes". But, if you might be able to use
"cython", then calling callbacks is not too difficult
(you can find an example in e.g. my "dm.xmlsec.binding").

Note, however, that properly handling the GIL ("Global Interpreter Lock")
may be of great importance when the Python/C boundary is crossed --
at least when you intend to use your code in a multi thread environment.



From stefan_ml at behnel.de  Thu May  9 02:57:55 2013
From: stefan_ml at behnel.de (Stefan Behnel)
Date: Thu, 09 May 2013 08:57:55 +0200
Subject: Help with implementing callback functions using ctypes
In-Reply-To: <87mws4bsum.fsf@handshake.de>
References: <8931a89c-0d00-4c8b-ba19-cf683d8d266d@googlegroups.com>
	<87mws4bsum.fsf@handshake.de>
Message-ID: <kmfhdf$j36$1@ger.gmane.org>

dieter, 09.05.2013 07:54:
> jamadagni writes:
>> ...
> I cannot help you with "ctypes". But, if you might be able to use
> "cython", then calling callbacks is not too difficult

+1 for using Cython. It also has (multi-)source level gdb support, which
greatly helps in debugging crashes like this one.

http://docs.cython.org/src/userguide/debugging.html


> (you can find an example in e.g. my "dm.xmlsec.binding").

An "official" example is here:

https://github.com/cython/cython/tree/master/Demos/callback


> Note, however, that properly handling the GIL ("Global Interpreter Lock")
> may be of great importance when the Python/C boundary is crossed --
> at least when you intend to use your code in a multi thread environment.

Cython makes this really easy. You can use the "with" statement to release
the GIL when you don't need it, and the compiler will produce errors when
you try to do things that require the GIL while you don't own it.

Stefan




From drsalists at gmail.com  Thu May 23 23:26:28 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Thu, 23 May 2013 20:26:28 -0700
Subject: Help with implementing callback functions using ctypes
In-Reply-To: <87mws4bsum.fsf@handshake.de>
References: <8931a89c-0d00-4c8b-ba19-cf683d8d266d@googlegroups.com>
	<87mws4bsum.fsf@handshake.de>
Message-ID: <CAGGBd_oDC2HFtbEJiV1ks8zHe_0a2yuLCBu7gaKpR+jGLS5DGQ@mail.gmail.com>

On Wed, May 8, 2013 at 10:54 PM, dieter <dieter at handshake.de> wrote:

> jamadagni <samjnaa at gmail.com> writes:
> > ...
> I cannot help you with "ctypes". But, if you might be able to use
> "cython", then calling callbacks is not too difficult
> (you can find an example in e.g. my "dm.xmlsec.binding").
>
> Note, however, that properly handling the GIL ("Global Interpreter Lock")
> may be of great importance when the Python/C boundary is crossed --
> at least when you intend to use your code in a multi thread environment.
>

Cython is good.

So is the new cffi, which might be thought of as a safer (API-level)
version of ctypes (which is ABI-level).
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From samjnaa at gmail.com  Sun May 26 12:12:10 2013
From: samjnaa at gmail.com (Shriramana Sharma)
Date: Sun, 26 May 2013 09:12:10 -0700 (PDT)
Subject: Help with implementing callback functions using ctypes
In-Reply-To: <mailman.2049.1369365991.3114.python-list@python.org>
References: <8931a89c-0d00-4c8b-ba19-cf683d8d266d@googlegroups.com>
	<87mws4bsum.fsf@handshake.de>
	<mailman.2049.1369365991.3114.python-list@python.org>
Message-ID: <8de1876e-c157-4012-9921-b981e079327d@googlegroups.com>

On Friday, May 24, 2013 8:56:28 AM UTC+5:30, Dan Stromberg wrote:
> Cython is good. So is the new cffi, which might be thought of as a 
> safer (API-level) version of ctypes (which is ABI-level).

Hi -- can you clarify what is this new CFFI and where I can get it? In the Python 3 library reference I seem to see only CTypes.


From carlosnepomuceno at outlook.com  Sun May 26 14:43:28 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 21:43:28 +0300
Subject: Help with implementing callback functions using ctypes
In-Reply-To: <8de1876e-c157-4012-9921-b981e079327d@googlegroups.com>
References: <8931a89c-0d00-4c8b-ba19-cf683d8d266d@googlegroups.com>,
	<87mws4bsum.fsf@handshake.de>,
	<mailman.2049.1369365991.3114.python-list@python.org>,
	<8de1876e-c157-4012-9921-b981e079327d@googlegroups.com>
Message-ID: <BLU176-W22AF1A7B5B439410B83389D7950@phx.gbl>

https://cffi.readthedocs.org/en/release-0.6/

----------------------------------------
> Date: Sun, 26 May 2013 09:12:10 -0700
> Subject: Re: Help with implementing callback functions using ctypes
> From: samjnaa at gmail.com
> To: python-list at python.org
>
> On Friday, May 24, 2013 8:56:28 AM UTC+5:30, Dan Stromberg wrote:
>> Cython is good. So is the new cffi, which might be thought of as a
>> safer (API-level) version of ctypes (which is ABI-level).
>
> Hi -- can you clarify what is this new CFFI and where I can get it? In the Python 3 library reference I seem to see only CTypes.
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From drsalists at gmail.com  Sun May 26 15:10:14 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Sun, 26 May 2013 12:10:14 -0700
Subject: Help with implementing callback functions using ctypes
In-Reply-To: <8de1876e-c157-4012-9921-b981e079327d@googlegroups.com>
References: <8931a89c-0d00-4c8b-ba19-cf683d8d266d@googlegroups.com>
	<87mws4bsum.fsf@handshake.de>
	<mailman.2049.1369365991.3114.python-list@python.org>
	<8de1876e-c157-4012-9921-b981e079327d@googlegroups.com>
Message-ID: <CAGGBd_q=gC7J+zTcOxo7WZiJkygTATT4P2jLzHq4MpJDfwZ+Yg@mail.gmail.com>

On Sun, May 26, 2013 at 9:12 AM, Shriramana Sharma <samjnaa at gmail.com>wrote:

> On Friday, May 24, 2013 8:56:28 AM UTC+5:30, Dan Stromberg wrote:
> > Cython is good. So is the new cffi, which might be thought of as a
> > safer (API-level) version of ctypes (which is ABI-level).
>
> Hi -- can you clarify what is this new CFFI and where I can get it? In the
> Python 3 library reference I seem to see only CTypes.
>

CFFI is like CTypes, but it allows you to do things like see C preprocessor
symbols.

https://cffi.readthedocs.org/en/release-0.6/

I don't think it comes with CPython, at least not yet.  But I believe it
comes with the latest Pypy.
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From nobody at nowhere.com  Thu May  9 14:32:08 2013
From: nobody at nowhere.com (Nobody)
Date: Thu, 09 May 2013 19:32:08 +0100
Subject: Help with implementing callback functions using ctypes
References: <8931a89c-0d00-4c8b-ba19-cf683d8d266d@googlegroups.com>
Message-ID: <pan.2013.05.09.18.32.14.40000@nowhere.com>

On Wed, 08 May 2013 04:19:07 -0700, jamadagni wrote:

> I have the below C program spiro.c (obviously a simplified testcase)
> which I compile to a sharedlib using clang -fPIC -shared -o libspiro.so
> spiro.c, sudo cp to /usr/lib and am trying to call from a Python script
> spiro.py using ctypes. However it would seem that the first call to the
> callback results in a segfault.

> # call the C function
> spiro_to_bezier_strict ( src, len ( src ), bc )

This line should be:

  spiro_to_bezier_strict ( src, len ( src ), byref(bc) )

Without the byref(...), it will try to pass a copy of the structure rather
than passing a pointer to it.



From samjnaa at gmail.com  Thu May 23 23:11:40 2013
From: samjnaa at gmail.com (jamadagni)
Date: Thu, 23 May 2013 20:11:40 -0700 (PDT)
Subject: Help with implementing callback functions using ctypes
In-Reply-To: <pan.2013.05.09.18.32.14.40000@nowhere.com>
References: <8931a89c-0d00-4c8b-ba19-cf683d8d266d@googlegroups.com>
	<pan.2013.05.09.18.32.14.40000@nowhere.com>
Message-ID: <4dd3853f-476b-47e7-9a20-d2752ca5cde1@googlegroups.com>

On Friday, May 10, 2013 12:02:08 AM UTC+5:30, Nobody wrote:
> This line should be:
>   spiro_to_bezier_strict ( src, len ( src ), byref(bc) )
> Without the byref(...), it will try to pass a copy of the structure rather
> than passing a pointer to it.

Wow silly silly mistake of mine, passing an object where a pointer is expected. Alternatively, if I specify:

spro_to_bezier_strict.argtypes = [ POINTER(spiro_cp), c_int, POINTER(bezctx) ]

it works equally good and apparently automatically converts the object specified to a pointer to it (which is good and intuitive, I guess, though against C practice).

I guess if one wants to be safe when interfacing to C functions, one should always specify argtypes (even if not restype).

But really, a segfault? I would expect a more meaningful error or an exception to be raised. Or is the black magic occurring at a level lower than where Python's control goes?

If I had seen this post I might not have even spent time on Cython. (For some reason Google Groups doesn't send me email updates even if I ask it to.) Using CTYpes I was able to implement a callback with less coding (for this particular requirement) than Cython which required an extra wrapper layer on top of the library to pass through a void* representing the Python callback (or a state variable would have to be used which may mean no thread-safety).

But I guess Cython would be faster for those who want that. Even though there is an extra function call every time (for the wrapper) it would be faster since it's at the C level rather than at the Python level (or something like that).

Thanks to all who helped on this, and also the people over at the cython-users list who helped me on the Cython wrapper too.


From roy at panix.com  Wed May  8 09:19:13 2013
From: roy at panix.com (Roy Smith)
Date: Wed, 08 May 2013 09:19:13 -0400
Subject: Unicode humor
Message-ID: <roy-9F57AC.09191308052013@news.panix.com>

Apropos to any of the myriad unicode threads that have been going on 
recently:

http://xkcd.com/1209/


From svenito at gmail.com  Wed May  8 10:30:22 2013
From: svenito at gmail.com (Sven)
Date: Wed, 8 May 2013 15:30:22 +0100
Subject: Unicode humor
In-Reply-To: <roy-9F57AC.09191308052013@news.panix.com>
References: <roy-9F57AC.09191308052013@news.panix.com>
Message-ID: <CAEH=cXVaqGkyaeOAsOLh-7i8pLGZrQfKH80p0dDg9utWHN=xHg@mail.gmail.com>

I saw this this morning and the first thing I thought of was this list...

unlike you I was too lazy to post it :)


On 8 May 2013 14:19, Roy Smith <roy at panix.com> wrote:

> Apropos to any of the myriad unicode threads that have been going on
> recently:
>
> http://xkcd.com/1209/
> --
> http://mail.python.org/mailman/listinfo/python-list
>



-- 
./Sven
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From auriocus at gmx.de  Wed May  8 13:16:03 2013
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Wed, 08 May 2013 19:16:03 +0200
Subject: Unicode humor
In-Reply-To: <roy-9F57AC.09191308052013@news.panix.com>
References: <roy-9F57AC.09191308052013@news.panix.com>
Message-ID: <kme11k$gj5$1@dont-email.me>

Am 08.05.13 15:19, schrieb Roy Smith:
> Apropos to any of the myriad unicode threads that have been going on
> recently:
>
> http://xkcd.com/1209/
>
http://xkcd.com/1137/




From wxjmfauth at gmail.com  Fri May 10 11:06:00 2013
From: wxjmfauth at gmail.com (jmfauth)
Date: Fri, 10 May 2013 08:06:00 -0700 (PDT)
Subject: Unicode humor
References: <roy-9F57AC.09191308052013@news.panix.com>
Message-ID: <3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>

On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
> Apropos to any of the myriad unicode threads that have been going on
> recently:
>
> http://xkcd.com/1209/

------


This reflects a lack of understanding of Unicode.

jmf


From rosuav at gmail.com  Fri May 10 11:16:36 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 11 May 2013 01:16:36 +1000
Subject: Unicode humor
In-Reply-To: <3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
Message-ID: <CAPTjJmrHwKV7tC=gsUW9_64Th0E_MQbHtY7C1hS3q6kYkf+KBA@mail.gmail.com>

On Sat, May 11, 2013 at 1:06 AM, jmfauth <wxjmfauth at gmail.com> wrote:
> On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
>> Apropos to any of the myriad unicode threads that have been going on
>> recently:
>>
>> http://xkcd.com/1209/
>
> ------
>
>
> This reflects a lack of understanding of Unicode.

By the skywriter, or by the two on the ground, or by Randall Munroe?

Or by jmf?

ChrisA


From ned at nedbatchelder.com  Fri May 10 11:24:36 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Fri, 10 May 2013 11:24:36 -0400
Subject: Unicode humor
In-Reply-To: <3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
Message-ID: <518D1134.40708@nedbatchelder.com>

On 5/10/2013 11:06 AM, jmfauth wrote:
> On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
>> Apropos to any of the myriad unicode threads that have been going on
>> recently:
>>
>> http://xkcd.com/1209/
> ------
>
>
> This reflects a lack of understanding of Unicode.
>
> jmf

And this reflects a lack of a sense of humor.  :)

--Ned.


From rosuav at gmail.com  Fri May 10 11:32:13 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 11 May 2013 01:32:13 +1000
Subject: Unicode humor
In-Reply-To: <518D1134.40708@nedbatchelder.com>
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
	<518D1134.40708@nedbatchelder.com>
Message-ID: <CAPTjJmp=zFB73FAsc-CFomSAW7T1h9nhga7RpVsYAiq0bdWSFw@mail.gmail.com>

On Sat, May 11, 2013 at 1:24 AM, Ned Batchelder <ned at nedbatchelder.com> wrote:
> On 5/10/2013 11:06 AM, jmfauth wrote:
>>
>> On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
>>>
>>> Apropos to any of the myriad unicode threads that have been going on
>>> recently:
>>>
>>> http://xkcd.com/1209/
>>
>> ------
>>
>>
>> This reflects a lack of understanding of Unicode.
>>
>> jmf
>
>
> And this reflects a lack of a sense of humor.  :)

Isn't that a crime in the UK?

ChrisA


From rustompmody at gmail.com  Fri May 10 12:07:45 2013
From: rustompmody at gmail.com (rusi)
Date: Fri, 10 May 2013 09:07:45 -0700 (PDT)
Subject: Unicode humor
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
	<518D1134.40708@nedbatchelder.com>
	<mailman.1536.1368199942.3114.python-list@python.org>
Message-ID: <1d320295-df6a-4feb-9921-0d6cce7f68a2@yb1g2000pbc.googlegroups.com>

On May 10, 8:32?pm, Chris Angelico <ros... at gmail.com> wrote:
> On Sat, May 11, 2013 at 1:24 AM, Ned Batchelder <n... at nedbatchelder.com> wrote:
> > On 5/10/2013 11:06 AM, jmfauth wrote:
>
> >> On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
>
> >>> Apropos to any of the myriad unicode threads that have been going on
> >>> recently:
>
> >>>http://xkcd.com/1209/
>
> >> ------
>
> >> This reflects a lack of understanding of Unicode.
>
> >> jmf
>
> > And this reflects a lack of a sense of humor. ?:)
>
> Isn't that a crime in the UK?
>
> ChrisA

The problem with English humour (as against standard humor) is that
its not unicode compliant


From python at mrabarnett.plus.com  Fri May 10 12:24:52 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 10 May 2013 17:24:52 +0100
Subject: Unicode humor
In-Reply-To: <1d320295-df6a-4feb-9921-0d6cce7f68a2@yb1g2000pbc.googlegroups.com>
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
	<518D1134.40708@nedbatchelder.com>
	<mailman.1536.1368199942.3114.python-list@python.org>
	<1d320295-df6a-4feb-9921-0d6cce7f68a2@yb1g2000pbc.googlegroups.com>
Message-ID: <518D1F54.8070900@mrabarnett.plus.com>

On 10/05/2013 17:07, rusi wrote:
> On May 10, 8:32 pm, Chris Angelico <ros... at gmail.com> wrote:
>> On Sat, May 11, 2013 at 1:24 AM, Ned Batchelder <n... at nedbatchelder.com> wrote:
>> > On 5/10/2013 11:06 AM, jmfauth wrote:
>>
>> >> On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
>>
>> >>> Apropos to any of the myriad unicode threads that have been going on
>> >>> recently:
>>
>> >>>http://xkcd.com/1209/
>>
>> >> ------
>>
>> >> This reflects a lack of understanding of Unicode.
>>
>> >> jmf
>>
>> > And this reflects a lack of a sense of humor.  :)
>>
>> Isn't that a crime in the UK?
>>
>> ChrisA
>
> The problem with English humour (as against standard humor) is that
> its not unicode compliant
>
British humour includes "double entendre", which is not French-compliant.


From jeanmichel at sequans.com  Wed May 15 09:19:00 2013
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Wed, 15 May 2013 15:19:00 +0200 (CEST)
Subject: Unicode humor
In-Reply-To: <518D1F54.8070900@mrabarnett.plus.com>
Message-ID: <1988041148.13863452.1368623940251.JavaMail.root@sequans.com>

> >> >> This reflects a lack of understanding of Unicode.
> >>
> >> >> jmf
> >>
> >> > And this reflects a lack of a sense of humor.  :)
> >>
> >> Isn't that a crime in the UK?
> >>
> >> ChrisA
> >
> > The problem with English humour (as against standard humor) is that
> > its not unicode compliant
> >
> British humour includes "double entendre", which is not
> French-compliant.

I didn't get that one. Which possibly confirm MRAB's statement.

JM


-- IMPORTANT NOTICE: 

The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

From darcy at druid.net  Wed May 15 10:09:59 2013
From: darcy at druid.net (D'Arcy J.M. Cain)
Date: Wed, 15 May 2013 10:09:59 -0400
Subject: Unicode humor
In-Reply-To: <1988041148.13863452.1368623940251.JavaMail.root@sequans.com>
References: <518D1F54.8070900@mrabarnett.plus.com>
	<1988041148.13863452.1368623940251.JavaMail.root@sequans.com>
Message-ID: <20130515100959.44d8e334@imp>

On Wed, 15 May 2013 15:19:00 +0200 (CEST)
Jean-Michel Pichavant <jeanmichel at sequans.com> wrote:
> > British humour includes "double entendre", which is not
> > French-compliant.
> 
> I didn't get that one. Which possibly confirm MRAB's statement.

It's sort of like when Bush said "The French don't even have a word for
entrepreneur."

-- 
D'Arcy J.M. Cain <darcy at druid.net>         |  Democracy is three wolves
http://www.druid.net/darcy/                |  and a sheep voting on
+1 416 788 2246     (DoD#0082)    (eNTP)   |  what's for dinner.
IM: darcy at Vex.Net, VOIP: sip:darcy at Vex.Net


From jeanmichel at sequans.com  Wed May 15 13:26:39 2013
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Wed, 15 May 2013 19:26:39 +0200 (CEST)
Subject: Unicode humor
In-Reply-To: <20130515100959.44d8e334@imp>
Message-ID: <49316535.14184594.1368638799329.JavaMail.root@sequans.com>

----- Original Message -----
> On Wed, 15 May 2013 15:19:00 +0200 (CEST)
> Jean-Michel Pichavant <jeanmichel at sequans.com> wrote:
> > > British humour includes "double entendre", which is not
> > > French-compliant.
> > 
> > I didn't get that one. Which possibly confirm MRAB's statement.
> 
> It's sort of like when Bush said "The French don't even have a word
> for
> entrepreneur."
> 
> --
> D'Arcy J.M. Cain <darcy at druid.net>         |  Democracy is three
> wolves
> http://www.druid.net/darcy/                |  and a sheep voting on
> +1 416 788 2246     (DoD#0082)    (eNTP)   |  what's for dinner.
> IM: darcy at Vex.Net, VOIP: sip:darcy at Vex.Net

Nice one (to MRAB's credit his humor was intentional :o) )

JM 


-- IMPORTANT NOTICE: 

The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

From python at mrabarnett.plus.com  Wed May 15 10:23:19 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 15 May 2013 15:23:19 +0100
Subject: Unicode humor
In-Reply-To: <1988041148.13863452.1368623940251.JavaMail.root@sequans.com>
References: <1988041148.13863452.1368623940251.JavaMail.root@sequans.com>
Message-ID: <51939A57.6000607@mrabarnett.plus.com>

On 15/05/2013 14:19, Jean-Michel Pichavant wrote:
>> >> >> This reflects a lack of understanding of Unicode.
>> >>
>> >> >> jmf
>> >>
>> >> > And this reflects a lack of a sense of humor.  :)
>> >>
>> >> Isn't that a crime in the UK?
>> >>
>> >> ChrisA
>> >
>> > The problem with English humour (as against standard humor) is that
>> > its not unicode compliant
>> >
>> British humour includes "double entendre", which is not
>> French-compliant.
>
> I didn't get that one. Which possibly confirm MRAB's statement.
>
It's called "double entendre" in English (using French words, from "?
double entente"), but that isn't correct French ("double sens").



From jeanmichel at sequans.com  Wed May 15 13:04:50 2013
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Wed, 15 May 2013 19:04:50 +0200 (CEST)
Subject: Unicode humor
In-Reply-To: <51939A57.6000607@mrabarnett.plus.com>
Message-ID: <1389756472.14167743.1368637490516.JavaMail.root@sequans.com>

----- Original Message -----
> On 15/05/2013 14:19, Jean-Michel Pichavant wrote:
> >> >> >> This reflects a lack of understanding of Unicode.
> >> >>
> >> >> >> jmf
> >> >>
> >> >> > And this reflects a lack of a sense of humor.  :)
> >> >>
> >> >> Isn't that a crime in the UK?
> >> >>
> >> >> ChrisA
> >> >
> >> > The problem with English humour (as against standard humor) is
> >> > that
> >> > its not unicode compliant
> >> >
> >> British humour includes "double entendre", which is not
> >> French-compliant.
> >
> > I didn't get that one. Which possibly confirm MRAB's statement.
> >
> It's called "double entendre" in English (using French words, from "?
> double entente"), but that isn't correct French ("double sens").

Thanks for clarifying, I didn't know "double entendre" had actually a meaning in english, it's obviously 2 french words but this is the first time I see them used together.

JM


-- IMPORTANT NOTICE: 

The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

From python at mrabarnett.plus.com  Wed May 15 13:21:01 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 15 May 2013 18:21:01 +0100
Subject: Unicode humor
In-Reply-To: <1389756472.14167743.1368637490516.JavaMail.root@sequans.com>
References: <1389756472.14167743.1368637490516.JavaMail.root@sequans.com>
Message-ID: <5193C3FD.2040304@mrabarnett.plus.com>

On 15/05/2013 18:04, Jean-Michel Pichavant wrote:
> ----- Original Message -----
>> On 15/05/2013 14:19, Jean-Michel Pichavant wrote:
>>>>>>>> This reflects a lack of understanding of Unicode.
>>>>>>
>>>>>>>> jmf
>>>>>>
>>>>>>> And this reflects a lack of a sense of humor.  :)
>>>>>>
>>>>>> Isn't that a crime in the UK?
>>>>>>
>>>>>> ChrisA
>>>>>
>>>>> The problem with English humour (as against standard humor)
>>>>> is that its not unicode compliant
>>>>>
>>>> British humour includes "double entendre", which is not
>>>> French-compliant.
>>>
>>> I didn't get that one. Which possibly confirm MRAB's statement.
>>>
>> It's called "double entendre" in English (using French words, from
>> "? double entente"), but that isn't correct French ("double
>> sens").
>
> Thanks for clarifying, I didn't know "double entendre" had actually a
> meaning in english, it's obviously 2 french words but this is the
> first time I see them used together.
>
Occasionally speakers of one language will borrow a word or phrase from
another language and use it in a way a native speaker wouldn't (or even
understand).


From cjw at ncf.ca  Wed May 15 15:37:21 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Wed, 15 May 2013 15:37:21 -0400
Subject: Unicode humor
In-Reply-To: <mailman.1710.1368638467.3114.python-list@python.org>
References: <1389756472.14167743.1368637490516.JavaMail.root@sequans.com>
	<mailman.1710.1368638467.3114.python-list@python.org>
Message-ID: <kn0o60$cit$1@theodyn.ncf.ca>

On 15/05/2013 1:21 PM, MRAB wrote:
> On 15/05/2013 18:04, Jean-Michel Pichavant wrote:
>> ----- Original Message -----
>>> On 15/05/2013 14:19, Jean-Michel Pichavant wrote:
>>>>>>>>> This reflects a lack of understanding of Unicode.
>>>>>>>
>>>>>>>>> jmf
>>>>>>>
>>>>>>>> And this reflects a lack of a sense of humor.  :)
>>>>>>>
>>>>>>> Isn't that a crime in the UK?
>>>>>>>
>>>>>>> ChrisA
>>>>>>
>>>>>> The problem with English humour (as against standard humor)
>>>>>> is that its not unicode compliant
>>>>>>
>>>>> British humour includes "double entendre", which is not
>>>>> French-compliant.
>>>>
>>>> I didn't get that one. Which possibly confirm MRAB's statement.
>>>>
>>> It's called "double entendre" in English (using French words, from
>>> "? double entente"), but that isn't correct French ("double
>>> sens").
>>
>> Thanks for clarifying, I didn't know "double entendre" had actually a
>> meaning in english, it's obviously 2 french words but this is the
>> first time I see them used together.
>>
> Occasionally speakers of one language will borrow a word or phrase from
> another language and use it in a way a native speaker wouldn't (or even
> understand).

double-entendre - Chambers Fails, but see Wiktionary: 
http://en.wiktionary.org/wiki/double_entendre

Colin W.


From wuwei23 at gmail.com  Wed May 15 19:57:13 2013
From: wuwei23 at gmail.com (alex23)
Date: Wed, 15 May 2013 16:57:13 -0700 (PDT)
Subject: Unicode humor
References: <518D1F54.8070900@mrabarnett.plus.com>
	<1988041148.13863452.1368623940251.JavaMail.root@sequans.com>
	<mailman.1700.1368627017.3114.python-list@python.org>
Message-ID: <a5bf2679-5aa7-4979-a1c9-06dc743ba14c@a15g2000pbu.googlegroups.com>

On May 16, 12:09?am, "D'Arcy J.M. Cain" <da... at druid.net> wrote:
> It's sort of like when Bush said "The French don't even have a word for
> entrepreneur."

Or "The Russians have no word for it, therefore detente must be a one-
way street."


From ethan at stoneleaf.us  Fri May 10 12:26:13 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Fri, 10 May 2013 09:26:13 -0700
Subject: Unicode humor
In-Reply-To: <1d320295-df6a-4feb-9921-0d6cce7f68a2@yb1g2000pbc.googlegroups.com>
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
	<518D1134.40708@nedbatchelder.com>
	<mailman.1536.1368199942.3114.python-list@python.org>
	<1d320295-df6a-4feb-9921-0d6cce7f68a2@yb1g2000pbc.googlegroups.com>
Message-ID: <518D1FA5.2080104@stoneleaf.us>

On 05/10/2013 09:07 AM, rusi wrote:
> On May 10, 8:32 pm, Chris Angelico <ros... at gmail.com> wrote:
>> On Sat, May 11, 2013 at 1:24 AM, Ned Batchelder <n... at nedbatchelder.com> wrote:
>>> On 5/10/2013 11:06 AM, jmfauth wrote:
>>
>>>> On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
>>
>>>>> Apropos to any of the myriad unicode threads that have been going on
>>>>> recently:
>>
>>>>> http://xkcd.com/1209/
>>
>>>> ------
>>
>>>> This reflects a lack of understanding of Unicode.
>>
>>>> jmf
>>
>>> And this reflects a lack of a sense of humor.  :)
>>
>> Isn't that a crime in the UK?
>>
>> ChrisA
>
> The problem with English humour (as against standard humor) is that
> its not unicode compliant

Is so!  It fits inside the first 127 code points!!

As a bonus it also takes less brain power^H^H^H^H^H^H^H^H^H space.  ;)

--
~Ethan~


From rosuav at gmail.com  Fri May 10 12:25:46 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 11 May 2013 02:25:46 +1000
Subject: Unicode humor
In-Reply-To: <1d320295-df6a-4feb-9921-0d6cce7f68a2@yb1g2000pbc.googlegroups.com>
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
	<518D1134.40708@nedbatchelder.com>
	<mailman.1536.1368199942.3114.python-list@python.org>
	<1d320295-df6a-4feb-9921-0d6cce7f68a2@yb1g2000pbc.googlegroups.com>
Message-ID: <CAPTjJmrzdmQnnMY6J+emanJjJC=dX1i8tkbvE7KM0JUnOoZ5oQ@mail.gmail.com>

On Sat, May 11, 2013 at 2:07 AM, rusi <rustompmody at gmail.com> wrote:
> On May 10, 8:32 pm, Chris Angelico <ros... at gmail.com> wrote:
>> On Sat, May 11, 2013 at 1:24 AM, Ned Batchelder <n... at nedbatchelder.com> wrote:
>> > On 5/10/2013 11:06 AM, jmfauth wrote:
>>
>> >> On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
>>
>> >>> Apropos to any of the myriad unicode threads that have been going on
>> >>> recently:
>>
>> >>>http://xkcd.com/1209/
>>
>> >> ------
>>
>> >> This reflects a lack of understanding of Unicode.
>>
>> >> jmf
>>
>> > And this reflects a lack of a sense of humor.  :)
>>
>> Isn't that a crime in the UK?
>>
>> ChrisA
>
> The problem with English humour (as against standard humor) is that
> its not unicode compliant

Unicode humour was carefully laid out to incorporate English humour.
In fact, if you use the standard variable-length-joke encoding, it's
possible for a Unicode joke to be decoded as if it were an English
joke, without any actual knowledge of Unicode. Unfortunately, this can
result in non-compliant English humour publishers producing jokes that
come out as gibberish in the rest of the world. Fortunately, we then
get to laugh at them.

ChrisA


From breamoreboy at yahoo.co.uk  Sat May 11 08:40:58 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 11 May 2013 13:40:58 +0100
Subject: Unicode humor
In-Reply-To: <CAPTjJmrzdmQnnMY6J+emanJjJC=dX1i8tkbvE7KM0JUnOoZ5oQ@mail.gmail.com>
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
	<518D1134.40708@nedbatchelder.com>
	<mailman.1536.1368199942.3114.python-list@python.org>
	<1d320295-df6a-4feb-9921-0d6cce7f68a2@yb1g2000pbc.googlegroups.com>
	<CAPTjJmrzdmQnnMY6J+emanJjJC=dX1i8tkbvE7KM0JUnOoZ5oQ@mail.gmail.com>
Message-ID: <kmle8s$1dr$1@ger.gmane.org>

On 10/05/2013 17:25, Chris Angelico wrote:
> On Sat, May 11, 2013 at 2:07 AM, rusi <rustompmody at gmail.com> wrote:
>> On May 10, 8:32 pm, Chris Angelico <ros... at gmail.com> wrote:
>>> On Sat, May 11, 2013 at 1:24 AM, Ned Batchelder <n... at nedbatchelder.com> wrote:
>>>> On 5/10/2013 11:06 AM, jmfauth wrote:
>>>
>>>>> On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
>>>
>>>>>> Apropos to any of the myriad unicode threads that have been going on
>>>>>> recently:
>>>
>>>>>> http://xkcd.com/1209/
>>>
>>>>> ------
>>>
>>>>> This reflects a lack of understanding of Unicode.
>>>
>>>>> jmf
>>>
>>>> And this reflects a lack of a sense of humor.  :)
>>>
>>> Isn't that a crime in the UK?
>>>
>>> ChrisA
>>
>> The problem with English humour (as against standard humor) is that
>> its not unicode compliant
>
> Unicode humour was carefully laid out to incorporate English humour.
> In fact, if you use the standard variable-length-joke encoding, it's
> possible for a Unicode joke to be decoded as if it were an English
> joke, without any actual knowledge of Unicode. Unfortunately, this can
> result in non-compliant English humour publishers producing jokes that
> come out as gibberish in the rest of the world. Fortunately, we then
> get to laugh at them.
>
> ChrisA
>

This simply shows bias to the English speaking world, as does Python 
unicode, at least in 3.3+.  I wouldn't mind betting that other languages 
can't cope, e.g. can 3.3+ manage the top secret joke that's so deadly 
even the Germans die laughing?

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From rosuav at gmail.com  Sat May 11 08:48:37 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 11 May 2013 22:48:37 +1000
Subject: Unicode humor
In-Reply-To: <kmle8s$1dr$1@ger.gmane.org>
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
	<518D1134.40708@nedbatchelder.com>
	<mailman.1536.1368199942.3114.python-list@python.org>
	<1d320295-df6a-4feb-9921-0d6cce7f68a2@yb1g2000pbc.googlegroups.com>
	<CAPTjJmrzdmQnnMY6J+emanJjJC=dX1i8tkbvE7KM0JUnOoZ5oQ@mail.gmail.com>
	<kmle8s$1dr$1@ger.gmane.org>
Message-ID: <CAPTjJmoQFa4vC=A7wzkpLArrxjYKcVayaaJuHQx5p+rP8qRU9Q@mail.gmail.com>

On Sat, May 11, 2013 at 10:40 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> This simply shows bias to the English speaking world, as does Python
> unicode, at least in 3.3+.  I wouldn't mind betting that other languages
> can't cope, e.g. can 3.3+ manage the top secret joke that's so deadly even
> the Germans die laughing?

It most certainly can. However, the space it takes up depends on how
you encode the combining characters; for maximal efficiency of
transmission, you would want to use the fully-composed version,
because like music, if it isn't composed, it's decomposed.

ChrisA


From steve+comp.lang.python at pearwood.info  Sat May 11 03:01:34 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 11 May 2013 07:01:34 GMT
Subject: Unicode humor
References: <roy-9F57AC.09191308052013@news.panix.com>
	<3e870f17-e7f5-4bcf-b848-f1947bad6859@k5g2000vbq.googlegroups.com>
	<mailman.1533.1368198999.3114.python-list@python.org>
Message-ID: <518decce$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sat, 11 May 2013 01:16:36 +1000, Chris Angelico wrote:

> On Sat, May 11, 2013 at 1:06 AM, jmfauth <wxjmfauth at gmail.com> wrote:
>> On 8 mai, 15:19, Roy Smith <r... at panix.com> wrote:
>>> Apropos to any of the myriad unicode threads that have been going on
>>> recently:
>>>
>>> http://xkcd.com/1209/
>>
>> ------
>>
>>
>> This reflects a lack of understanding of Unicode.
> 
> By the skywriter, or by the two on the ground, or by Randall Munroe?

Obviously by all three. It takes *hours* to execute

'?'*1000.replace('?', '?')

using a skywriting plane, so obviously it isn't Unicode compliant.



-- 
Steven


From kdawg44 at gmail.com  Wed May  8 14:52:59 2013
From: kdawg44 at gmail.com (Kevin Holleran)
Date: Wed, 8 May 2013 14:52:59 -0400
Subject: MySQL Database
Message-ID: <CAN4UfGzbtM1vtW4EvmjYq0gDAcCzaQTJrPKhuk=VTTTwgH7sZQ@mail.gmail.com>

Hello,

I want to connect to a MySQL database, query for some records, manipulate
some data, and then update the database.

When I do something like this:

    db_c.execute("SELECT a, b FROM Users")

    for row in db_c.fetchall():

        (r,d) = row[0].split('|')

        (g,e) = domain.split('.')

        db_c.execute("UPDATE Users SET g = '" + g + "' WHERE a ='" + row[0])

Will using db_c to update the database mess up the loop that is cycling
through db_c.fetchall()?

Thanks for your help.

Kevin
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From rosuav at gmail.com  Wed May  8 14:56:59 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 9 May 2013 04:56:59 +1000
Subject: MySQL Database
In-Reply-To: <CAN4UfGzbtM1vtW4EvmjYq0gDAcCzaQTJrPKhuk=VTTTwgH7sZQ@mail.gmail.com>
References: <CAN4UfGzbtM1vtW4EvmjYq0gDAcCzaQTJrPKhuk=VTTTwgH7sZQ@mail.gmail.com>
Message-ID: <CAPTjJmosQnSU=1W1tfbiJy7DSz3YV5njsFAj0kOghMemZSAXoQ@mail.gmail.com>

On Thu, May 9, 2013 at 4:52 AM, Kevin Holleran <kdawg44 at gmail.com> wrote:
> Will using db_c to update the database mess up the loop that is cycling
> through db_c.fetchall()?

Nope; fetchall() returns a list, which you're then iterating over.
Nothing the database does can disrupt that.

ChrisA


From kdawg44 at gmail.com  Wed May  8 15:04:27 2013
From: kdawg44 at gmail.com (Kevin Holleran)
Date: Wed, 8 May 2013 15:04:27 -0400
Subject: MySQL Database
In-Reply-To: <CAPTjJmosQnSU=1W1tfbiJy7DSz3YV5njsFAj0kOghMemZSAXoQ@mail.gmail.com>
References: <CAN4UfGzbtM1vtW4EvmjYq0gDAcCzaQTJrPKhuk=VTTTwgH7sZQ@mail.gmail.com>
	<CAPTjJmosQnSU=1W1tfbiJy7DSz3YV5njsFAj0kOghMemZSAXoQ@mail.gmail.com>
Message-ID: <CAN4UfGxeFJ5WMhj4EqL=4D1JXHpYjGQ_KU1zBEZzttWEDfydXA@mail.gmail.com>

On Wed, May 8, 2013 at 2:56 PM, Chris Angelico <rosuav at gmail.com> wrote:

> On Thu, May 9, 2013 at 4:52 AM, Kevin Holleran <kdawg44 at gmail.com> wrote:
> > Will using db_c to update the database mess up the loop that is cycling
> > through db_c.fetchall()?
>
> Nope; fetchall() returns a list, which you're then iterating over.
> Nothing the database does can disrupt that.
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list
>

Awesome.  That was my hope...

Thanks for your help & quick response.

Kevin
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From python at mrabarnett.plus.com  Wed May  8 15:07:39 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 08 May 2013 20:07:39 +0100
Subject: MySQL Database
In-Reply-To: <CAN4UfGzbtM1vtW4EvmjYq0gDAcCzaQTJrPKhuk=VTTTwgH7sZQ@mail.gmail.com>
References: <CAN4UfGzbtM1vtW4EvmjYq0gDAcCzaQTJrPKhuk=VTTTwgH7sZQ@mail.gmail.com>
Message-ID: <518AA27B.20409@mrabarnett.plus.com>

On 08/05/2013 19:52, Kevin Holleran wrote:
> Hello,
>
> I want to connect to a MySQL database, query for some records,
> manipulate some data, and then update the database.
>
> When I do something like this:
>
>      db_c.execute("SELECT a, b FROM Users")
>
> for row in db_c.fetchall():
>
>          (r,d) = row[0].split('|')
>
>          (g,e) = domain.split('.')
>
>          db_c.execute("UPDATE Users SET g = '"+ g + "' WHERE a ='"+ row[0])
>
>
> Will using db_c to update the database mess up the loop that is cycling
> through db_c.fetchall()?
>
You shouldn't be building an SQL string like that because it's
susceptible to SQL injection. You should be doing it more like this:

db_c.execute("UPDATE Users SET g = %s WHERE a = %s", (g, row[0]))

The values will then be handled safely for you.


From kdawg44 at gmail.com  Wed May  8 15:31:02 2013
From: kdawg44 at gmail.com (Kevin Holleran)
Date: Wed, 8 May 2013 15:31:02 -0400
Subject: MySQL Database
In-Reply-To: <518AA27B.20409@mrabarnett.plus.com>
References: <CAN4UfGzbtM1vtW4EvmjYq0gDAcCzaQTJrPKhuk=VTTTwgH7sZQ@mail.gmail.com>
	<518AA27B.20409@mrabarnett.plus.com>
Message-ID: <CAN4UfGwHinQGB6aJ6R-rXWBVjSQV4rxGyjQnqSyKNL1wNrwLzg@mail.gmail.com>

Thanks,  I actually intend to, was just whipping something up to be an
example for my question.



--
Kevin Holleran
Master of Science, Computer Information Systems
Grand Valley State University
Master of Business Administration
Western Michigan University
GCFA, GCFE, CCNA, ISA, MCSA, MCDST, MCP

"Do today what others won't, do tomorrow what others can't" - SEALFit

"We are what we repeatedly do. Excellence, then, is not an act, but a
habit." - Aristotle


On Wed, May 8, 2013 at 3:07 PM, MRAB <python at mrabarnett.plus.com> wrote:

> On 08/05/2013 19:52, Kevin Holleran wrote:
>
>> Hello,
>>
>> I want to connect to a MySQL database, query for some records,
>> manipulate some data, and then update the database.
>>
>> When I do something like this:
>>
>>      db_c.execute("SELECT a, b FROM Users")
>>
>> for row in db_c.fetchall():
>>
>>          (r,d) = row[0].split('|')
>>
>>          (g,e) = domain.split('.')
>>
>>          db_c.execute("UPDATE Users SET g = '"+ g + "' WHERE a ='"+
>> row[0])
>>
>>
>> Will using db_c to update the database mess up the loop that is cycling
>> through db_c.fetchall()?
>>
>>  You shouldn't be building an SQL string like that because it's
> susceptible to SQL injection. You should be doing it more like this:
>
> db_c.execute("UPDATE Users SET g = %s WHERE a = %s", (g, row[0]))
>
> The values will then be handled safely for you.
> --
> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>
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From haoyi.sg at gmail.com  Wed May  8 16:09:53 2013
From: haoyi.sg at gmail.com (Haoyi Li)
Date: Wed, 8 May 2013 13:09:53 -0700 (PDT)
Subject: ANN: MacroPy: quasiquotes, case classes, LINQ and more! Now available
	on PyPI
Message-ID: <c06f62e3-3157-4b69-9939-9479fe2f828c@googlegroups.com>

Hey All,

MacroPy is an implementation of Macros in Python which lets you very easily modify the semantics of a python program. Apart from the implementation of macros themselves, we also have a pretty impressive list of feature demos that were implemented on top of macros:

- Quasiquotes, a quick way to manipulate fragments of a program
- String Interpolation, a common feature in many languages
- Pyxl, integrating XML markup into a Python program
- Tracing and Smart Asserts
- Case Classes, easy Algebraic Data Types from Scala
- Pattern Matching from the Functional Programming world
- LINQ to SQL from C#
- Quick Lambdas from Scala and Groovy,
- Parser Combinators, inspired by Scala's.

The full documentation is over on github (https://github.com/lihaoyi/macropy) if anyone wants to check it out. It runs fine on both CPython 2.7 and PyPy 1.9, and I've just pushed the last up-to-date version of MacroPy to PyPI: 

https://pypi.python.org/pypi/MacroPy

Hope someone finds this useful!

Thanks!
-Haoyi


From roy at panix.com  Wed May  8 16:20:48 2013
From: roy at panix.com (Roy Smith)
Date: 8 May 2013 16:20:48 -0400
Subject: Style question -- plural of class name?
Message-ID: <kmec30$d12$1@panix2.panix.com>

FooEntry is a class.  How would you describe a list of these in a
docstring?

"A list of FooEntries"

"A list of FooEntrys"

"A list of FooEntry's"

"A list of FooEntry instances"

The first one certainly sounds the best, but it seems wierd to change
the spelling of the class name to make it plural.


From skip at pobox.com  Wed May  8 16:33:07 2013
From: skip at pobox.com (Skip Montanaro)
Date: Wed, 8 May 2013 15:33:07 -0500
Subject: Style question -- plural of class name?
In-Reply-To: <kmec30$d12$1@panix2.panix.com>
References: <kmec30$d12$1@panix2.panix.com>
Message-ID: <CANc-5UxRyX3FEtU+O_-ZwPZMTarkJBC1TBh8-i15z54Qs1-rNQ@mail.gmail.com>

This one:

> "A list of FooEntry instances"

Besides the obvious spelling issues in the others, it's not
immediately clear if the list contains just FooEntry instances,
FooEntry classes (perhaps subclasses) or a mix of the two.  #4 makes
it clear.

Skip


From john.a.downs at gmail.com  Wed May  8 16:37:05 2013
From: john.a.downs at gmail.com (John Downs)
Date: Wed, 8 May 2013 16:37:05 -0400
Subject: Style question -- plural of class name?
In-Reply-To: <kmec30$d12$1@panix2.panix.com>
References: <kmec30$d12$1@panix2.panix.com>
Message-ID: <CAFbFFS8_6zCS3CowezbX409S_tPohwpgfKdPTW=--uK5Ehkj2Q@mail.gmail.com>

On Wed, May 8, 2013 at 4:20 PM, Roy Smith <roy at panix.com> wrote:

> FooEntry is a class.  How would you describe a list of these in a
> docstring?
>
> "A list of FooEntries"
>
> "A list of FooEntrys"
>
> "A list of FooEntry's"
>
> "A list of FooEntry instances"
>
> The first one certainly sounds the best, but it seems wierd to change
> the spelling of the class name to make it plural.
> --
> http://mail.python.org/mailman/listinfo/python-list
>

How about: "A list with elements of type FooEntry"?  I also like the last
one: "A list of FooEntry instances".
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From ian.g.kelly at gmail.com  Wed May  8 16:45:14 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 8 May 2013 14:45:14 -0600
Subject: Style question -- plural of class name?
In-Reply-To: <CAFbFFS8_6zCS3CowezbX409S_tPohwpgfKdPTW=--uK5Ehkj2Q@mail.gmail.com>
References: <kmec30$d12$1@panix2.panix.com>
	<CAFbFFS8_6zCS3CowezbX409S_tPohwpgfKdPTW=--uK5Ehkj2Q@mail.gmail.com>
Message-ID: <CALwzidmgo3fdxfqq5xCQ3NbQ6Ssf6WG4TkfkCn+Dq8c129qxXw@mail.gmail.com>

On Wed, May 8, 2013 at 2:37 PM, John Downs <john.a.downs at gmail.com> wrote:
> On Wed, May 8, 2013 at 4:20 PM, Roy Smith <roy at panix.com> wrote:
>>
>> FooEntry is a class.  How would you describe a list of these in a
>> docstring?
>>
>> "A list of FooEntries"
>>
>> "A list of FooEntrys"
>>
>> "A list of FooEntry's"
>>
>> "A list of FooEntry instances"
>>
>> The first one certainly sounds the best, but it seems wierd to change
>> the spelling of the class name to make it plural.
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
>
> How about: "A list with elements of type FooEntry"?  I also like the last
> one: "A list of FooEntry instances".

list<FooEntry>

*ducks*


From denismfmcmahon at gmail.com  Wed May  8 18:40:54 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Wed, 8 May 2013 22:40:54 +0000 (UTC)
Subject: Style question -- plural of class name?
References: <kmec30$d12$1@panix2.panix.com>
Message-ID: <kmek9m$s0v$1@dont-email.me>

On Wed, 08 May 2013 16:20:48 -0400, Roy Smith wrote:

> FooEntry is a class.  How would you describe a list of these in a
> docstring?
> 
> "A list of FooEntries"
> 
> "A list of FooEntrys"
> 
> "A list of FooEntry's"
> 
> "A list of FooEntry instances"
> 
> The first one certainly sounds the best, but it seems wierd to change
> the spelling of the class name to make it plural.

I wouldn't use an apostrophe for pluralisation.

The Normal pluralisation of FooEntry would be FooEntries. Who are you 
expecting to read the docstring? English majors, grammar nazis, wikipedia 
editors, programmers, or all 4?

-- 
Denis McMahon, denismfmcmahon at gmail.com


From neilc at norwich.edu  Thu May  9 11:14:17 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 9 May 2013 15:14:17 GMT
Subject: Style question -- plural of class name?
References: <kmec30$d12$1@panix2.panix.com> <kmek9m$s0v$1@dont-email.me>
Message-ID: <av1sq9Fqug0U2@mid.individual.net>

On 2013-05-08, Denis McMahon <denismfmcmahon at gmail.com> wrote:
> On Wed, 08 May 2013 16:20:48 -0400, Roy Smith wrote:
>
>> FooEntry is a class.  How would you describe a list of these in a
>> docstring?
>> 
>> "A list of FooEntries"
>> 
>> "A list of FooEntrys"
>> 
>> "A list of FooEntry's"
>> 
>> "A list of FooEntry instances"
>> 
>> The first one certainly sounds the best, but it seems wierd to change
>> the spelling of the class name to make it plural.
>
> I wouldn't use an apostrophe for pluralisation.

If there's no chance for confusion between a class named FooEntry
and another named FooEntries, then the first attempt seems best.
Pluralize a class name by following the usual rules, e.g.,
"strings" and "ints".

-- 
Neil Cerutti


From jpiitula at ling.helsinki.fi  Thu May  9 12:43:23 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 09 May 2013 19:43:23 +0300
Subject: Style question -- plural of class name?
References: <kmec30$d12$1@panix2.panix.com> <kmek9m$s0v$1@dont-email.me>
	<av1sq9Fqug0U2@mid.individual.net>
Message-ID: <qotppx0w1ck.fsf@ruuvi.it.helsinki.fi>

Neil Cerutti writes:

> If there's no chance for confusion between a class named FooEntry
> and another named FooEntries, then the first attempt seems best.
> Pluralize a class name by following the usual rules, e.g.,
> "strings" and "ints".

Like "strings" would be "foo entries". Which might work well.

(I mean, isn't the class named "str"?)


From neilc at norwich.edu  Thu May  9 13:28:41 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 9 May 2013 17:28:41 GMT
Subject: Style question -- plural of class name?
References: <kmec30$d12$1@panix2.panix.com> <kmek9m$s0v$1@dont-email.me>
	<av1sq9Fqug0U2@mid.individual.net>
	<qotppx0w1ck.fsf@ruuvi.it.helsinki.fi>
Message-ID: <av24m9FgnmU1@mid.individual.net>

On 2013-05-09, Jussi Piitulainen <jpiitula at ling.helsinki.fi> wrote:
> Neil Cerutti writes:
>> If there's no chance for confusion between a class named
>> FooEntry and another named FooEntries, then the first attempt
>> seems best. Pluralize a class name by following the usual
>> rules, e.g., "strings" and "ints".
>
> Like "strings" would be "foo entries". Which might work well.
>
> (I mean, isn't the class named "str"?)

Yeah, that's not such a good Python example. I used it to replace
"chars" and felt good at the time. ;)

-- 
Neil Cerutti


From steve+comp.lang.python at pearwood.info  Wed May  8 20:02:18 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 00:02:18 GMT
Subject: Style question -- plural of class name?
References: <kmec30$d12$1@panix2.panix.com>
Message-ID: <518ae78a$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Wed, 08 May 2013 16:20:48 -0400, Roy Smith wrote:

> FooEntry is a class.  How would you describe a list of these in a
> docstring?


Which language are you writing your docstrings in? Obey the normal rules 
of spelling, grammar and punctuation for your language, which I assume is 
English.


> "A list of FooEntries"

Perfectly acceptable.


> "A list of FooEntrys"

There is no standard variant or dialect of English (British English, 
American English, etc.) that pluralises Entry as Entrys, so that would be 
"absolutely not".


> "A list of FooEntry's"

"Here come's an S! Quick, jam on an apostrophe!"

This is called the grocer's apostrophe, and is universally held in 
contempt no matter what variant of English you write in. Don't do this.

The only acceptable use of an apostrophe to make a plural is if the thing 
being pluralised is a single letter. E.g. one a, two a's.

 
> "A list of FooEntry instances"

This is also acceptable, although a little wordy. Do you write "a list of 
strings" or "a list of str instances"?


> The first one certainly sounds the best, but it seems wierd to change
> the spelling of the class name to make it plural.

No weirder (note spelling) than changing any other noun. Whether you 
change "int" to "ints" or FooEntry" to "FooEntries", you're still 
changing it. That's how you make it plural.


-- 
Steven


From cs at zip.com.au  Wed May  8 20:42:44 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Thu, 9 May 2013 10:42:44 +1000
Subject: Style question -- plural of class name?
In-Reply-To: <518ae78a$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <518ae78a$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20130509004244.GA17531@cskk.homeip.net>

On 09May2013 00:02, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
| On Wed, 08 May 2013 16:20:48 -0400, Roy Smith wrote:
| > "A list of FooEntry's"
| 
| "Here come's an S! Quick, jam on an apostrophe!"
| 
| This is called the grocer's apostrophe, and is universally held in 
| contempt no matter what variant of English you write in. Don't do this.
| 
| The only acceptable use of an apostrophe to make a plural is if the thing 
| being pluralised is a single letter. E.g. one a, two a's.

Frankly, not even then for me. I spell that "one A, two As".

| > "A list of FooEntry instances"
| 
| This is also acceptable, although a little wordy. Do you write "a list of 
| strings" or "a list of str instances"?

How about "a FooEntry list"?
-- 
Cameron Simpson <cs at zip.com.au>

Yes Officer, yes Officer, I will Officer. Thank you.


From rosuav at gmail.com  Wed May  8 20:12:46 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 9 May 2013 10:12:46 +1000
Subject: Style question -- plural of class name?
In-Reply-To: <kmec30$d12$1@panix2.panix.com>
References: <kmec30$d12$1@panix2.panix.com>
Message-ID: <CAPTjJmqL9_xHqSY0DO2B_+LRW8ERzKh9krkdxXNvNZtgBTyBdg@mail.gmail.com>

On Thu, May 9, 2013 at 6:20 AM, Roy Smith <roy at panix.com> wrote:
> "A list of FooEntry's"

Only if you put another apostrophe in:

"A list of 'FooEntry's"

But the delimited style is almost never of use. I'd go for this only
if there were some sort of automated markup being applied - if the
word FooEntry were turned into a hyperlink or something.

ChrisA


From steve+comp.lang.python at pearwood.info  Wed May  8 20:13:09 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 00:13:09 GMT
Subject: Style question -- plural of class name?
References: <kmec30$d12$1@panix2.panix.com>
	<mailman.1459.1368045196.3114.python-list@python.org>
Message-ID: <518aea14$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Wed, 08 May 2013 15:33:07 -0500, Skip Montanaro wrote:

> This one:
> 
>> "A list of FooEntry instances"
> 
> Besides the obvious spelling issues in the others, it's not immediately
> clear if the list contains just FooEntry instances, FooEntry classes
> (perhaps subclasses) or a mix of the two.  #4 makes it clear.


I don't think this is a real issue. There isn't normally any ambiguity 
between instances and subclasses. When you read "a list of ints", do you 
assume that the list looks like [int, MyInt, AnotherInt, FooInt] or do 
you expect it to look like [2, 7, 6, 1]?

The normal interpretation of "one or more Foo" is that we're talking 
about Foo *instances*, not subclasses of Foo. If that is not that case, 
then the onus is on the author of the documentation to make it clear that 
they are talking about subclasses.


-- 
Steven


From cjw at ncf.ca  Wed May  8 20:38:36 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Wed, 08 May 2013 20:38:36 -0400
Subject: Style question -- plural of class name?
In-Reply-To: <kmec30$d12$1@panix2.panix.com>
References: <kmec30$d12$1@panix2.panix.com>
Message-ID: <518AF00C.8030207@ncf.ca>

On 08/05/2013 4:20 PM, Roy Smith wrote:
> FooEntry is a class.  How would you describe a list of these in a
> docstring?
>
> "A list of FooEntries"  0
>
> "A list of FooEntrys"   -1
>
> "A list of FooEntry's"  +1
>
> "A list of FooEntry instances"  No FooEntry is specified as a class.
>
> The first one certainly sounds the best, but it seems wierd to change
> the spelling of the class name to make it plural.
>

Colin W.


From nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915 at spamschutz.glglgl.de  Thu May  9 06:21:10 2013
From: nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915 at spamschutz.glglgl.de (Thomas Rachel)
Date: Thu, 09 May 2013 12:21:10 +0200
Subject: Style question -- plural of class name?
In-Reply-To: <518AF00C.8030207@ncf.ca>
References: <kmec30$d12$1@panix2.panix.com> <518AF00C.8030207@ncf.ca>
Message-ID: <kmftan$20s$1@r01.glglgl.de>

Am 09.05.2013 02:38 schrieb Colin J. Williams:
> On 08/05/2013 4:20 PM, Roy Smith wrote:
>>
>> "A list of FooEntry's"  +1

Go back to school. Both of you...

That is NOT the way to build a plural form...


Thomas


From robert.kern at gmail.com  Thu May  9 13:44:17 2013
From: robert.kern at gmail.com (Robert Kern)
Date: Thu, 09 May 2013 18:44:17 +0100
Subject: Style question -- plural of class name?
In-Reply-To: <kmec30$d12$1@panix2.panix.com>
References: <kmec30$d12$1@panix2.panix.com>
Message-ID: <kmgn9c$egn$1@ger.gmane.org>

On 2013-05-08 21:20, Roy Smith wrote:
> FooEntry is a class.  How would you describe a list of these in a
> docstring?
>
> "A list of FooEntries"
>
> "A list of FooEntrys"
>
> "A list of FooEntry's"
>
> "A list of FooEntry instances"
>
> The first one certainly sounds the best, but it seems wierd to change
> the spelling of the class name to make it plural.

I'm using services like Github more and more to talk about code, so I have taken 
to adopting its inline markup for `code` when referring to identifiers. Thus, I 
will often write

   A list of `FooEntry`s

But I don't mind

   A list of FooEntries

Hopefully there isn't also a `FooEntries` class.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco



From flexage at gmail.com  Wed May  8 16:50:43 2013
From: flexage at gmail.com (flexage at gmail.com)
Date: Wed, 8 May 2013 13:50:43 -0700 (PDT)
Subject: Globally available I/O connection (K8055 I/O board)
Message-ID: <c1c5718f-07b3-45c7-ba28-3bb9164b5210@googlegroups.com>

I'm having a bit of an issue trying to make a globally available connection to my Velleman K8055 I/O board...

I've documented my issue as best I can here: http://stackoverflow.com/questions/16449706/python-access-global-instance-of-connection

Could anybody shed some light on a way to combat my problem?


From davea at davea.name  Wed May  8 17:20:54 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 08 May 2013 17:20:54 -0400
Subject: Globally available I/O connection (K8055 I/O board)
In-Reply-To: <c1c5718f-07b3-45c7-ba28-3bb9164b5210@googlegroups.com>
References: <c1c5718f-07b3-45c7-ba28-3bb9164b5210@googlegroups.com>
Message-ID: <518AC1B6.9070402@davea.name>

On 05/08/2013 04:50 PM, flexage at gmail.com wrote:
> I'm having a bit of an issue trying to make a globally available connection to my Velleman K8055 I/O board...
>
> I've documented my issue as best I can here: http://stackoverflow.com/questions/16449706/python-access-global-instance-of-connection
>

I don't think that's a Python question at all.  You have some constraint 
your hardware gives you that requires you to run function k8055(0) once, 
and to use that result object to access the board subsequently.  Looks 
to me like you're doing exactly that.  Are there any other calls to that 
function in your code?

If you were messing up with your access to the global object 
globalK8055, you'd get an exception.

The only Python mistake I can think of that you might be doing is if 
you're using your script as a module, or otherwise doing circular 
imports, or if you're accessing some module under more than one name.

In particular, if you run SmartyPi/appglobals.py as a script, it'd be 
calling the k8055() function once and saving the value.  And then when 
somebody imports it as
     from smartypi.appglobals import globalK8055 as k

they'd get a NEW instance of the module and a new value for globalK8055.

If you have some form of logging mechanism (including print), you could 
record each time the k8055() is called.


-- 
DaveA


From ricardo.lelis3 at gmail.com  Wed May  8 19:47:47 2013
From: ricardo.lelis3 at gmail.com (rlelis)
Date: Wed, 8 May 2013 16:47:47 -0700 (PDT)
Subject: help on Implementing a list of dicts with no data pattern
Message-ID: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>

Hi guys,

I'm working on this long file, where i have to keep reading and
storing different excerpts of text (data) in different variables (list).

Once done that i want to store in dicts the data i got from the lists mentioned before. I want them on a list of dicts for later RDBMs purpose's.

The data i'm working with, don't have fixed pattern (see example bellow), so what i'm doing is for each row, i want to store combinations of  word/value (Key-value) to keep track of all the data.

My problem is that once i'm iterating over the list (original one a.k.a file_content in the link), then i'm nesting several if clause to match
the keys i want. Done that i select the keys i want to give them values and lastly i append that dict into a new list. The problem here is that i end up always with the last line repeated several times for each row it found's.

Please take a look on what i have now:
http://pastebin.com/A9eka7p9


From davea at davea.name  Wed May  8 20:05:15 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 08 May 2013 20:05:15 -0400
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
Message-ID: <518AE83B.1070702@davea.name>

On 05/08/2013 07:47 PM, rlelis wrote:
> Hi guys,
>

Please read this http://wiki.python.org/moin/GoogleGroupsPython.


> I'm working on this long file, where i have to keep reading and
> storing different excerpts of text (data) in different variables (list).
>
> Once done that i want to store in dicts the data i got from the lists mentioned before. I want them on a list of dicts for later RDBMs purpose's.
>
> The data i'm working with, don't have fixed pattern (see example bellow), so what i'm doing is for each row, i want to store combinations of  word/value (Key-value) to keep track of all the data.
>
> My problem is that once i'm iterating over the list (original one a.k.a file_content in the link), then i'm nesting several if clause to match
> the keys i want. Done that i select the keys i want to give them values and lastly i append that dict into a new list. The problem here is that i end up always with the last line repeated several times for each row it found's.
>
> Please take a look on what i have now:
> http://pastebin.com/A9eka7p9
>

If you want a response here, please post the code here.  If it's over 50 
lines, simplify it first.  And be sure and tell us what version of 
Python and what other dependencies you might have.  And what OS you're 
targeting.


-- 
DaveA


From python at mrabarnett.plus.com  Wed May  8 20:16:10 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 09 May 2013 01:16:10 +0100
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
Message-ID: <518AEACA.5040206@mrabarnett.plus.com>

On 09/05/2013 00:47, rlelis wrote:
> Hi guys,
>
> I'm working on this long file, where i have to keep reading and
> storing different excerpts of text (data) in different variables (list).
>
> Once done that i want to store in dicts the data i got from the lists mentioned before. I want them on a list of dicts for later RDBMs purpose's.
>
> The data i'm working with, don't have fixed pattern (see example bellow), so what i'm doing is for each row, i want to store combinations of  word/value (Key-value) to keep track of all the data.
>
> My problem is that once i'm iterating over the list (original one a.k.a file_content in the link), then i'm nesting several if clause to match
> the keys i want. Done that i select the keys i want to give them values and lastly i append that dict into a new list. The problem here is that i end up always with the last line repeated several times for each row it found's.
>
> Please take a look on what i have now:
> http://pastebin.com/A9eka7p9
>
You're creating a dict for highway_dict and a dict for aging_dict, and
then using those dicts for every iteration of the 'for' loop.

You're also appending both of the dicts onto the 'queue_row' list for
every iteration of the 'for' loop.

I think that what you meant to do was, for each match, to create a
dict, populate it, and then append it to the list.


From ricardo.lelis3 at gmail.com  Thu May  9 05:57:47 2013
From: ricardo.lelis3 at gmail.com (rlelis)
Date: Thu, 9 May 2013 02:57:47 -0700 (PDT)
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
Message-ID: <826082ef-43e2-4835-8621-6ef677eb922c@googlegroups.com>

On Thursday, May 9, 2013 12:47:47 AM UTC+1, rlelis wrote:
> Hi guys,
> 
> 
> 
> I'm working on this long file, where i have to keep reading and
> 
> storing different excerpts of text (data) in different variables (list).
> 
> 
> 
> Once done that i want to store in dicts the data i got from the lists mentioned before. I want them on a list of dicts for later RDBMs purpose's.
> 
> 
> 
> The data i'm working with, don't have fixed pattern (see example bellow), so what i'm doing is for each row, i want to store combinations of  word/value (Key-value) to keep track of all the data.
> 
> 
> 
> My problem is that once i'm iterating over the list (original one a.k.a file_content in the link), then i'm nesting several if clause to match
> 
> the keys i want. Done that i select the keys i want to give them values and lastly i append that dict into a new list. The problem here is that i end up always with the last line repeated several times for each row it found's.
> 
> 
> 
> Please take a look on what i have now:
> 
> http://pastebin.com/A9eka7p9

Sorry, i thought that a link to pastebin could be helpfully since it captures the syntax highlights and spacings. I don't have a fifty line code there. The 25 lines below, where to show you guys a picture of what is going on, to be more intuitive.
This is what i have for now:

highway_dict = {}
aging_dict = {}
queue_row = []
for content in file_content:
	if 'aging' in content:
		# aging 0 100
		collumns = ''.join(map(str, content[:1])).replace('-','_').lower()
		total_values =''.join(map(str, content[1:2]))
		aging_values = ''.join(map(str, content[2:]))

		aging_dict['total'], aging_dict[collumns] = total, aging_values
	queue_row.append(aging_dict)

	if 'highway' in content:
		#highway	|	4 	|	disable |	25
		collumns = ''.join(map(str, content[:1])).replace('-','_').lower()
		lanes_values  =''.join(map(str, content[1:2]))		
		state_values = ''.join(map(str, content[2:3])).strip('')
		limit_values = ''.join(map(str, content[3:4])).strip('')
		
		highway_dict['lanes'], highway_dict['state'], highway_dict['limit(mph)'] = lanes, state, limit_values
	queue_row.append(highway_dict)


From davea at davea.name  Thu May  9 08:26:03 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 09 May 2013 08:26:03 -0400
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <826082ef-43e2-4835-8621-6ef677eb922c@googlegroups.com>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
	<826082ef-43e2-4835-8621-6ef677eb922c@googlegroups.com>
Message-ID: <518B95DB.2000207@davea.name>

On 05/09/2013 05:57 AM, rlelis wrote:
> On Thursday, May 9, 2013 12:47:47 AM UTC+1, rlelis wrote:
>> Hi guys,
>>
>>
>>
>> I'm working on this long file, where i have to keep reading and
>>
>> storing different excerpts of text (data) in different variables (list).
>>
>>
>>
>> Once done that i want to store in dicts the data i got from the lists mentioned before. I want them on a list of dicts for later RDBMs purpose's.
>>
>>
>>
>> The data i'm working with, don't have fixed pattern (see example bellow), so what i'm doing is for each row, i want to store combinations of  word/value (Key-value) to keep track of all the data.
>>
>>
>>
>> My problem is that once i'm iterating over the list (original one a.k.a file_content in the link), then i'm nesting several if clause to match
>>
>> the keys i want. Done that i select the keys i want to give them values and lastly i append that dict into a new list. The problem here is that i end up always with the last line repeated several times for each row it found's.
>>
>>
>>
>> Please take a look on what i have now:
>>
>> http://pastebin.com/A9eka7p9
>
> Sorry, i thought that a link to pastebin could be helpfully since it captures the syntax highlights and spacings. I don't have a fifty line code there. The 25 lines below, where to show you guys a picture of what is going on, to be more intuitive.
> This is what i have for now:
>

The entire following set of comments is probably outdated since you 
apparently did NOT use readlines() or equivalent to get file_content. 
So you'd better give us some sample data, a program that can actually 
run without getting exceptions due to misnamed variables, and a 
description of just what you expected to be in each result variable.

It'd also be smart to mention what version of Python you're targeting.

.... what follows was a waste of my time ...

file_content is not defined, but we can guess you have read it from a 
text file with readlines(), or more efficiently that it's simply a file 
object for a file opened with "r".  Can we see sample data, maybe for 3 
or four lines?

file_content = [
     "A4 value2 aging",
     "b8 value99 paging",
     "-1 this is aging a test",
     "B2  repeaagingts",
     ]

The sample, or the description, should indicate if repeats of the 
"columns" column are allowed, as with b and B above.

> highway_dict = {}
> aging_dict = {}
> queue_row = []
> for content in file_content:
> 	if 'aging' in content:
> 		# aging 0 100
> 		collumns = ''.join(map(str, content[:1])).replace('-','_').lower()
> 		total_values =''.join(map(str, content[1:2]))
> 		aging_values = ''.join(map(str, content[2:]))

Those three lines would be much more reasonable and readable if you 
eliminated all the list stuff, and just did what was needed.  Also, 
calling a one-character string "collumns" or "total_values" makes no 
sense to me.

                 collumns = content[:1].replace('-','_').lower()
   		total_values = content[1:2]
  		aging_values = content[2:]

>
> 		aging_dict['total'], aging_dict[collumns] = total, aging_values

That line tries to get clever, and ends up obscuring what's really 
happening.  Further, the value in total, if any is NOT what you just 
extracted in total_values.
  		aging_dict['total'] = total
  		aging_dict[collumns] = aging_values


> 	queue_row.append(aging_dict)

Just what do you expect to be in the aging_dict here?  If you intended 
that each item of queue_row contains a dict with just one item, then you 
need to clear aging_dict each time through the loop.  As it stands the 
list ends up with a bunch of dicts, each with possibly one more entry 
than the previous dict.

All the same remarks apply to the following code.  Additionally, you 
don't use collumns for anything, and you use lanes and state when you 
presumably meant lanes_values and state_values.
>
> 	if 'highway' in content:


> 		#highway	|	4 	|	disable |	25
> 		collumns = ''.join(map(str, content[:1])).replace('-','_').lower()
> 		lanes_values  =''.join(map(str, content[1:2]))		
> 		state_values = ''.join(map(str, content[2:3])).strip('')
> 		limit_values = ''.join(map(str, content[3:4])).strip('')
> 		
> 		highway_dict['lanes'], highway_dict['state'], highway_dict['limit(mph)'] = lanes, state, limit_values
> 	queue_row.append(highway_dict)
>

Now, when

-- 
DaveA


From neilc at norwich.edu  Thu May  9 09:08:56 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 9 May 2013 13:08:56 GMT
Subject: help on Implementing a list of dicts with no data pattern
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
	<826082ef-43e2-4835-8621-6ef677eb922c@googlegroups.com>
Message-ID: <av1lf7Fqug0U1@mid.individual.net>

On 2013-05-09, rlelis <ricardo.lelis3 at gmail.com> wrote:
> This is what i have for now:
>
> highway_dict = {}
> aging_dict = {}
> queue_row = []
> for content in file_content:
> 	if 'aging' in content:
> 		# aging 0 100
> 		collumns = ''.join(map(str, content[:1])).replace('-','_').lower()
> 		total_values =''.join(map(str, content[1:2]))
> 		aging_values = ''.join(map(str, content[2:]))
>
> 		aging_dict['total'], aging_dict[collumns] = total, aging_values
> 	queue_row.append(aging_dict)
>
> 	if 'highway' in content:
> 		#highway	|	4 	|	disable |	25
> 		collumns = ''.join(map(str, content[:1])).replace('-','_').lower()
> 		lanes_values  =''.join(map(str, content[1:2]))		
> 		state_values = ''.join(map(str, content[2:3])).strip('')
> 		limit_values = ''.join(map(str, content[3:4])).strip('')
> 		
> 		highway_dict['lanes'], highway_dict['state'], highway_dict['limit(mph)'] = lanes, state, limit_values
> 	queue_row.append(highway_dict)

Can you provide a short example of input and what you had hoped
to see in the lists and dicts at the end?

-- 
Neil Cerutti


From ricardo.lelis3 at gmail.com  Thu May  9 10:33:28 2013
From: ricardo.lelis3 at gmail.com (rlelis)
Date: Thu, 9 May 2013 07:33:28 -0700 (PDT)
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
Message-ID: <fd60505e-3a05-41e3-aecc-c812a24f5077@googlegroups.com>

I apologize once again. 
Is my first post here and i'm getting used to the group as long as i get the feedback of my errors by you guys.
I'm using Python 2.7.3 with no dependencies, i'm simply using the standard
library.
Here is the "big picture" of the scenario(i have added it in the pastebin link too) 

FILE OUTPUT DESIRED:
aging:
aging  |total         |age
aging  |0             |100
aging  |2             |115
aging  |3             |1
aging  |4             |10

highway:
highway       | lanes         |       state   |       limit(mph)
highway       |       4       |       disable |       25
highway       |       2       |       disable |       245
highway       |       3       |       disable |       125
highway       |       2       |       enable  |       255
highway       |       3       |       disable |       212
highway       |       8       |       disable |       78

FILE INPUT EXCERPT EXAMPLE:
aging 0 100
aging 2 115
aging 3 1
highway 4 disable 25
highway 2 disable 245
highway 0 enable 125

Meanwhile i have change the code a little bit and achieve a output closer to what i want:
highway_dict = {}
aging_dict = {}
queue_counters={}
queue_row = []
for content in file_content: 
        if 'aging' in content:
                # aging 0 100
                columns = ', '.join(map(str, content[:1])).replace('-','_').lower()
                total_values =''.join(map(str, content[1:2]))
                aging_values = '\t'.join(map(str, content[2:]))
 
                aging_dict['total'], aging_dict[columns] = total, aging_values
                queue_counters[columns] = aging_dict
        if 'highway' in content:
                #highway        |       4       |       disable |       25
                columns = ''.join(map(str, content[:1])).replace('-','_').lower()
                lanes_values  =''.join(map(str, content[1:2]))         
                state_values = ''.join(map(str, content[2:3])).strip('')
                limit_values = ''.join(map(str, content[3:4])).strip('')
               
                highway_dict['lanes'], highway_dict['state'], highway_dict['limit(mph)'] = lanes, state, limit_values
                queue_counters[columns] = highway_dict
        queue_row.append(queue_counters)

Now i'm adding the different dicts to a "main" one (queue_counters). The problem here is that i'm keeping falling on the iteration issue. I only get the last row on my ouput. My last printout was:

queue_counters:  {'aging': {'age': '10', 'total': '4'}, 'highway': {'lanes': '8','state': 'disable', 'limit': '78'}} 

@Dave Angel  

"The sample, or the description, should indicate if repeats of the 
"columns" column are allowed, as with b and B above. "
- Yes the columns repetition are allowed.

"That line tries to get clever, and ends up obscuring what's really 
happening.  Further, the value in total, if any is NOT what you just 
extracted in total_values."
- this variable name total_values means that i'm storing the content (different values)of the total column, and the same applies to the other columns (might
not be the best names, but don't forget that we are just prototyping here). The total, age, etc etc variable name i had to set them, once they don't come with the original file, but is important to give them names to help on RDBMs purposes later, and not only that, it's handy right?

The column variable refers to the object name (aging and highway). I'm doing that because in the original source i have to deal with string formatting of 
strange names. Remember that this is for prototyping, that's why i'm trying to 
resume things here.


From davea at davea.name  Thu May  9 10:50:45 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 09 May 2013 10:50:45 -0400
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <fd60505e-3a05-41e3-aecc-c812a24f5077@googlegroups.com>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
	<fd60505e-3a05-41e3-aecc-c812a24f5077@googlegroups.com>
Message-ID: <518BB7C5.2060900@davea.name>

On 05/09/2013 10:33 AM, rlelis wrote:
> I apologize once again.
> Is my first post here and i'm getting used to the group as long as i get the feedback of my errors by you guys.
> I'm using Python 2.7.3 with no dependencies, i'm simply using the standard
> library.
> Here is the "big picture" of the scenario(i have added it in the pastebin link too)
>
> FILE OUTPUT DESIRED:
> aging:
> aging  |total         |age
> aging  |0             |100
> aging  |2             |115
> aging  |3             |1
> aging  |4             |10
>
> highway:
> highway       | lanes         |       state   |       limit(mph)
> highway       |       4       |       disable |       25
> highway       |       2       |       disable |       245
> highway       |       3       |       disable |       125
> highway       |       2       |       enable  |       255
> highway       |       3       |       disable |       212
> highway       |       8       |       disable |       78
>
> FILE INPUT EXCERPT EXAMPLE:
> aging 0 100
> aging 2 115
> aging 3 1
> highway 4 disable 25
> highway 2 disable 245
> highway 0 enable 125
>
> Meanwhile i have change the code a little bit and achieve a output closer to what i want:

You're still missing the file read code.  My earlier assumption that it 
was a simple readlines() was bogus, or the line:
    if "aging" in file-content:

would never work.

Perhaps you have something like:

infile = open("xxxx","r")
file_content = [line.split() for line in infile]

if you confirm it, I'll try to go through the code again, trying to make 
sense of it.



-- 
DaveA


From ricardo.lelis3 at gmail.com  Thu May  9 12:14:14 2013
From: ricardo.lelis3 at gmail.com (rlelis)
Date: Thu, 9 May 2013 09:14:14 -0700 (PDT)
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
Message-ID: <5bc1d8b8-61b1-446d-8487-1e72c1ddf925@googlegroups.com>

On Thursday, May 9, 2013 12:47:47 AM UTC+1, rlelis wrote:
@Dave Angel
this is how i mange to read and store the data in file.
data = []
# readdata
f = open(source_file, 'r')
for line in f:
        header = (line.strip()).lower()
        # conditions(if/else clauses) on the header content to filter desired data 
        data.append(header)


From davea at davea.name  Thu May  9 14:19:38 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 09 May 2013 14:19:38 -0400
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <5bc1d8b8-61b1-446d-8487-1e72c1ddf925@googlegroups.com>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
	<5bc1d8b8-61b1-446d-8487-1e72c1ddf925@googlegroups.com>
Message-ID: <518BE8BA.6050501@davea.name>

On 05/09/2013 12:14 PM, rlelis wrote:
> On Thursday, May 9, 2013 12:47:47 AM UTC+1, rlelis wrote:
> @Dave Angel
> this is how i mange to read and store the data in file.
> data = []
> # readdata
> f = open(source_file, 'r')
> for line in f:
>          header = (line.strip()).lower()
>          # conditions(if/else clauses) on the header content to filter desired data
>          data.append(header)
>

 From earlier message:
 > highway_dict = {}
 > aging_dict = {}
 > queue_counters={}
 > queue_row = []
 > for content in file_content:
         if 'aging' in content:

So your data is a list of strings, each representing one line of the 
file.  When you run this, you'll get something like:

NameError: name 'file_content' is not defined

If I assume you've just neglected to include the assignment, 
file_content = data, then the next problem is

          if 'aging' in content:

will never fire.  Likewise
         if 'highway' in content:

will never fire.  So the rest of the code is irrelevant.

-- 
DaveA


From ricardo.lelis3 at gmail.com  Thu May  9 17:22:59 2013
From: ricardo.lelis3 at gmail.com (rlelis)
Date: Thu, 9 May 2013 14:22:59 -0700 (PDT)
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <mailman.1500.1368123592.3114.python-list@python.org>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
	<5bc1d8b8-61b1-446d-8487-1e72c1ddf925@googlegroups.com>
	<mailman.1500.1368123592.3114.python-list@python.org>
Message-ID: <3bcb3a3a-f1e2-4e31-b917-6a4391ddb9fa@googlegroups.com>

On Thursday, May 9, 2013 7:19:38 PM UTC+1, Dave Angel wrote:

Yes it's a list of string. I don't get the NameError: name 'file_content' is not defined in my code.

After i appended the headers i wanted to cut the data list it little bit more because there was some data (imagine some other collumns) to the left that didn't needed.

file_content = []
for d in data:
    file_content.append(d[1:])

from this point on i've showed the code,
highway_dict = {} 
aging_dict = {} 
queue_counters={} 
queue_row = [] 
for content in file_content: 
        if 'aging' in content: 
                # aging 0 100
                # code here
 
etc, etc


From davea at davea.name  Thu May  9 18:32:21 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 09 May 2013 18:32:21 -0400
Subject: help on Implementing a list of dicts with no data pattern
In-Reply-To: <3bcb3a3a-f1e2-4e31-b917-6a4391ddb9fa@googlegroups.com>
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
	<5bc1d8b8-61b1-446d-8487-1e72c1ddf925@googlegroups.com>
	<mailman.1500.1368123592.3114.python-list@python.org>
	<3bcb3a3a-f1e2-4e31-b917-6a4391ddb9fa@googlegroups.com>
Message-ID: <518C23F5.3070002@davea.name>

On 05/09/2013 05:22 PM, rlelis wrote:
> On Thursday, May 9, 2013 7:19:38 PM UTC+1, Dave Angel wrote:
>
> Yes it's a list of string. I don't get the NameError: name 'file_content' is not defined in my code.

That's because you have the 3 lines below which we hadn't seen yet.

>
> After i appended the headers i wanted to cut the data list it little bit more because there was some data (imagine some other collumns) to the left that didn't needed.
>
> file_content = []
> for d in data:
>      file_content.append(d[1:])
>
> from this point on i've showed the code,
> highway_dict = {}
> aging_dict = {}
> queue_counters={}
> queue_row = []
> for content in file_content:
>          if 'aging' in content:
>                  # aging 0 100
>                  # code here
>

OK, so I now have some code I can actually run.  Unfortunately, it 
produces an error:

Traceback (most recent call last):
   File "ricardo.py", line 23, in <module>
     aging_dict['total'], aging_dict[columns] = total, aging_values
NameError: name 'total' is not defined

So I'll make a reasonable guess that you meant total_values there.  I 
still can't understand how you're testing this code, when there are 
trivial bugs in it.

Next, I get:

Traceback (most recent call last):
   File "ricardo.py", line 32, in <module>
     highway_dict['lanes'], highway_dict['state'], 
highway_dict['limit(mph)'] = lanes, state, limit_values
NameError: name 'lanes' is not defined

and then:

Traceback (most recent call last):
   File "ricardo.py", line 32, in <module>
     highway_dict['lanes'], highway_dict['state'], 
highway_dict['limit(mph)'] = lanes_values, state, limit_values
NameError: name 'state' is not defined

Each of those not-defined errors was pointed out by me earlier in the 
thread.

I don't see any output logic, so I guess it's up to us to guess what the 
meanings and scope of the various lists and dicts are.  I figure the 
queue_row is your final collection that you hope to get results from. 
It's a list containing many references to a single queue_counters 
object.  So naturally, they all look the same.

If you want them to be different, you have to create a new one each 
time.  Move the line:
     queue_counters={}

inside the loop, right after the line:
     for content in file_content:

There are a bunch of other things wrong, like not lining up the columns 
when you're substringing content, but this may be your major stumbling 
block.  Note:  you may have to also move the highway_dict and 
aging_dict;  I haven't figured out what they're for, yet.

Following is the code I've been using to try to figure out what you were 
intending:


file_content = [
         "aging 0 100",
         "aging 2 115",
         "aging 3 1",
         "highway 4 disable 25",
         "highway 2 disable 245",
         "highway 0 enable 125",
     ]

highway_dict = {}
aging_dict = {}
#queue_counters={}
queue_row = []
for content in file_content:
         queue_counters={}
         if 'aging' in content:
                 # aging 0 100
                 columns = ', '.join(map(str, 
content[:1])).replace('-','_').lower()
                 print "columns:", columns
                 total_values =''.join(map(str, content[1:2]))
                 aging_values = '\t'.join(map(str, content[2:]))

                 aging_dict['total'], aging_dict[columns] = 
total_values, aging_values
                 queue_counters[columns] = aging_dict
         if 'highway' in content:
                 #highway        |       4       |       disable |       25
                 columns = ''.join(map(str, 
content[:1])).replace('-','_').lower()
                 lanes_values  =''.join(map(str, content[1:2]))
                 state_values = ''.join(map(str, content[2:3])).strip('')
                 limit_values = ''.join(map(str, content[3:4])).strip('')

                 highway_dict['lanes'], highway_dict['state'], 
highway_dict['limit(mph)'] = lanes_values, state_values, limit_values
                 queue_counters[columns] = highway_dict
         queue_row.append(queue_counters)


print
print "h dict:", highway_dict
print
print "aging dict:", aging_dict
print
print "q counters:", queue_counters
for key, item in  queue_counters.iteritems():
     print key, item

print
print "q row:", queue_row
for item in queue_row:
     print item






-- 
DaveA


From neilc at norwich.edu  Fri May 10 08:54:43 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 10 May 2013 12:54:43 GMT
Subject: help on Implementing a list of dicts with no data pattern
References: <c27c3eef-44f5-467c-b3a3-119263deb035@googlegroups.com>
	<5bc1d8b8-61b1-446d-8487-1e72c1ddf925@googlegroups.com>
	<mailman.1500.1368123592.3114.python-list@python.org>
	<3bcb3a3a-f1e2-4e31-b917-6a4391ddb9fa@googlegroups.com>
	<mailman.1508.1368138770.3114.python-list@python.org>
Message-ID: <av490jFeje1U1@mid.individual.net>

On 2013-05-09, Dave Angel <davea at davea.name> wrote:
> On 05/09/2013 05:22 PM, rlelis wrote:
>> On Thursday, May 9, 2013 7:19:38 PM UTC+1, Dave Angel wrote:
>>
>> Yes it's a list of string. I don't get the NameError: name 'file_content' is not defined in my code.
>
> That's because you have the 3 lines below which we hadn't seen yet.

Heroic efforts, Dave!

To rlelis:

Do not start to program until you understand what you want to do.
Work it out on a sheet of paper, or at least in your mind.

If you can't provide sample input and the expected output from
it, chances are you aren't ready to start writing code.

-- 
Neil Cerutti


From valbendan at outlook.com  Thu May  9 00:10:40 2013
From: valbendan at outlook.com (dabaichi)
Date: Thu, 9 May 2013 12:10:40 +0800
Subject: Anybody familiar with pygments ?
Message-ID: <kmf7cf$2e26$1@adenine.netfront.net>

Hello guys:
pygments version: 1.6
python version :3.3.1(64bits, use msi installer install)
os:windows 7 (64bits)
Hereis my python source code:

#!/usr/bin/env python
#-*- coding=utf-8 -*-

import os
import sys
from pygments import highlight as html_highlight
from pygments.lexers import get_lexer_by_name
from pygments.formatters import HtmlFormatter
from pygments.styles import get_style_by_name

def highlight(filename):
    formatter = HtmlFormatter(linenos=True, style="vim")
    filename_split = filename.split('.')

    if len(filename_split) == 1:
        return None

    lexer = get_lexer_by_name(filename_split[len(filename_split) - 1])

    try:
        with open(filename, 'r') as fp:
            content = fp.read()
    except Exception:
        return None

    html_content = html_highlight(content, lexer, formatter)
    return html_content

def main():
    filename = r'test.c'
    print(highlight(filename))

if __name__ == "__main__":
    main()


Here is test.c source code:
#include <stdio.h>

int main(int argc, char * argv[])
{
    printf("This is a test!\n");
    return 0;
}

And hereis the output file:
<table class="highlighttable"><tr><td class="linenos"><div 
class="linenodiv"><pre>1
2
3
4
5
6
7</pre></div></td><td class="code"><div class="highlight"><pre><span 
class="cp">#include &lt;stdio.h&gt;</span>

<span class="kt">int</span> <span class="nf">main</span><span 
class="p">(</span><span class="kt">int</span> <span 
class="n">argc</span><span class="p">,</span> <span class="kt">char</span> 
<span class="o">*</span> <span class="n">argv</span><span 
class="p">[])</span>
<span class="p">{</span>
    <span class="n">printf</span><span class="p">(</span><span 
class="s">&quot;This is a test!</span><span class="se">\n</span><span 
class="s">&quot;</span><span class="p">);</span>
    <span class="k">return</span> <span class="mi">0</span><span 
class="p">;</span>
<span class="p">}</span>
</pre></div>
</td></tr></table>

It looks like:
1 #include <stdio.h>
2
3 int main(int argc, char * argv[])
4 {
5     printf("This is a test!\n");
6     return 0;
7 }
8
with no color in firefox (20.0.1)

I want to know why output html file with no color ?
Is my code error ?

Best regard!
--peipei 


--- news://freenews.netfront.net/ - complaints: news at netfront.net ---


From fabiosantosart at gmail.com  Thu May  9 04:40:09 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 9 May 2013 09:40:09 +0100
Subject: Anybody familiar with pygments ?
In-Reply-To: <kmf7cf$2e26$1@adenine.netfront.net>
References: <kmf7cf$2e26$1@adenine.netfront.net>
Message-ID: <CAA=1kxT32Kj5mWZOCz3x9YLsPQjkb3=H1d+0p0t3Zq5f-OyHrw@mail.gmail.com>

On 9 May 2013 05:19, "dabaichi" <valbendan at outlook.com> wrote:
>
> And hereis the output file:

That's not the output file. That is just an HTML fragment to put on your
page. A full HTML file will need more things, which is the reason why you
don't see color output.

> I want to know why output html file with no color ?

Because there is no CSS. The output  has a lot of <span> tags with classes.
You are supposed to use a CSS file along with it.

So, first put that output into a complete HTML document (with a head, a
body...) And in that document add or link to your CSS file with the color
information. I never used pygments but there may be some readily available.
-------------- next part --------------
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From kwpolska at gmail.com  Fri May 10 11:24:10 2013
From: kwpolska at gmail.com (=?UTF-8?B?Q2hyaXMg4oCcS3dwb2xza2HigJ0gV2Fycmljaw==?=)
Date: Fri, 10 May 2013 17:24:10 +0200
Subject: Anybody familiar with pygments ?
In-Reply-To: <CAA=1kxT32Kj5mWZOCz3x9YLsPQjkb3=H1d+0p0t3Zq5f-OyHrw@mail.gmail.com>
References: <kmf7cf$2e26$1@adenine.netfront.net>
	<CAA=1kxT32Kj5mWZOCz3x9YLsPQjkb3=H1d+0p0t3Zq5f-OyHrw@mail.gmail.com>
Message-ID: <CAMw+j7JuNte_Z=rkz4uhdRaQ65VvqKzmG9RDXFLHrsbyXZW7kw@mail.gmail.com>

On Thu, May 9, 2013 at 10:40 AM, F?bio Santos <fabiosantosart at gmail.com> wrote:
>
> On 9 May 2013 05:19, "dabaichi" <valbendan at outlook.com> wrote:
>>
>> And hereis the output file:
>
> That's not the output file. That is just an HTML fragment to put on your
> page. A full HTML file will need more things, which is the reason why you
> don't see color output.
>
>> I want to know why output html file with no color ?
>
> Because there is no CSS. The output  has a lot of <span> tags with classes.
> You are supposed to use a CSS file along with it.
>
> So, first put that output into a complete HTML document (with a head, a
> body...) And in that document add or link to your CSS file with the color
> information. I never used pygments but there may be some readily available.
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>

First off, the Python code was unnecessary in this case, because it
would be cheaper to use the pygmentize app included.

Second off, CSS is available at
https://github.com/richleland/pygments-css or by running `pygmentize
-f html -O full FILE`.

--
Kwpolska <http://kwpolska.tk> | GPG KEY: 5EAAEA16
stop html mail                | always bottom-post
http://asciiribbon.org        | http://caliburn.nl/topposting.html


From omrahulrajcse at gmail.com  Thu May  9 02:36:28 2013
From: omrahulrajcse at gmail.com (RAHUL RAJ)
Date: Wed, 8 May 2013 23:36:28 -0700 (PDT)
Subject: Append to python List
Message-ID: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>

Checkout the following code:

sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]   
output=[]
output=[x for x in sample2 if x not in output]

the output I get is
3 4 5 6 7 8 9 10 3 5 6 7 8 9 10 11 4 5 7 8 9 10 11 12 5 6 7 9 10 11 12 13 6 7 8 9 11 12 13 14 7 8 9 10 11 13 14 15 8 9 10 11 12 13 15 16 9 10 11 12 13 14 15 17 10 11 12 13 14 15 16 17

which contains duplicate values.




But if I do like this:

sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]   
output=[]
for x in sample2:
  if x not in output:
     output.append(x)


the value of 'output' I get like this:
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

I know that both the programs have the same functionality, but why do I have different outputs?

Please help!


From jpiitula at ling.helsinki.fi  Thu May  9 02:55:20 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 09 May 2013 09:55:20 +0300
Subject: Append to python List
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
Message-ID: <qotobck8wx3.fsf@ruuvi.it.helsinki.fi>

RAHUL RAJ writes:

> Checkout the following code:
> 
> sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]   
> output=[]
> output=[x for x in sample2 if x not in output]
> 
> the output I get is
> 3 4 5 6 7 8 9 10 3 5 6 7 8 9 10 11 4 5 7 8 9 10 11 12 5 6 7 9 10 11
> 12 13 6 7 8 9 11 12 13 14 7 8 9 10 11 13 14 15 8 9 10 11 12 13 15 16
> 9 10 11 12 13 14 15 17 10 11 12 13 14 15 16 17
> 
> which contains duplicate values.

The second comprehension, [x for x in sample2 if x not in output], in
the context, is equivalent to [x for x in sample2 if x not in []]. It
does not refer to an incomplete version of the list that gets assigned
to the variable after it's done.


From dihedral88888 at googlemail.com  Thu May  9 07:24:53 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Thu, 9 May 2013 04:24:53 -0700 (PDT)
Subject: Append to python List
In-Reply-To: <qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
Message-ID: <11dfb7f9-9bbb-4e42-bce9-027efffabcf3@googlegroups.com>

Jussi Piitulainen? 2013?5?9????UTC+8??2?55?20????
> RAHUL RAJ writes:
> 
> 
> 
> > Checkout the following code:
> 
> > 
> 
> > sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]   
> 
> > output=[]
> 
> > output=[x for x in sample2 if x not in output]
> 
> > 
> 
> > the output I get is
> 
> > 3 4 5 6 7 8 9 10 3 5 6 7 8 9 10 11 4 5 7 8 9 10 11 12 5 6 7 9 10 11
> 
> > 12 13 6 7 8 9 11 12 13 14 7 8 9 10 11 13 14 15 8 9 10 11 12 13 15 16
> 
> > 9 10 11 12 13 14 15 17 10 11 12 13 14 15 16 17
> 
> > 
> 
> > which contains duplicate values.
> 
> 
> 
> The second comprehension, [x for x in sample2 if x not in output], in
> 
> the context, is equivalent to [x for x in sample2 if x not in []]. It
> 
> does not refer to an incomplete version of the list that gets assigned
> 
> to the variable after it's done.

This is just the handy style for a non-critical loop.
In a critical loop, the number of  the total operation counts
does matter in the execution speed.


From jpiitula at ling.helsinki.fi  Thu May  9 07:30:05 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 09 May 2013 14:30:05 +0300
Subject: Append to python List
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
	<11dfb7f9-9bbb-4e42-bce9-027efffabcf3@googlegroups.com>
Message-ID: <qottxmccrwi.fsf@ruuvi.it.helsinki.fi>

88888 Dihedral writes:

> This is just the handy style for a non-critical loop.
> In a critical loop, the number of  the total operation counts
> does matter in the execution speed.

Do you use speed often?


From rosuav at gmail.com  Thu May  9 07:49:42 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 9 May 2013 21:49:42 +1000
Subject: Append to python List
In-Reply-To: <qottxmccrwi.fsf@ruuvi.it.helsinki.fi>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
	<11dfb7f9-9bbb-4e42-bce9-027efffabcf3@googlegroups.com>
	<qottxmccrwi.fsf@ruuvi.it.helsinki.fi>
Message-ID: <CAPTjJmqPHgEMrnX_AaM07rSywbrDkJZy9t+ONg4fmf75By=mNg@mail.gmail.com>

On Thu, May 9, 2013 at 9:30 PM, Jussi Piitulainen
<jpiitula at ling.helsinki.fi> wrote:
> 88888 Dihedral writes:
>
>> This is just the handy style for a non-critical loop.
>> In a critical loop, the number of  the total operation counts
>> does matter in the execution speed.
>
> Do you use speed often?

Dihedral is a bot. Quite a good one, but a bot.

ChrisA


From dihedral88888 at googlemail.com  Fri May 10 05:51:57 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Fri, 10 May 2013 02:51:57 -0700 (PDT)
Subject: Append to python List
In-Reply-To: <qottxmccrwi.fsf@ruuvi.it.helsinki.fi>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
	<11dfb7f9-9bbb-4e42-bce9-027efffabcf3@googlegroups.com>
	<qottxmccrwi.fsf@ruuvi.it.helsinki.fi>
Message-ID: <34c6abdd-91f3-4c24-bb82-bd5063902bd0@googlegroups.com>

Jussi Piitulainen? 2013?5?9????UTC+8??7?30?05????
> 88888 Dihedral writes:
> 
> 
> 
> > This is just the handy style for a non-critical loop.
> 
> > In a critical loop, the number of  the total operation counts
> 
> > does matter in the execution speed.


> 
> 
> 
> Do you use speed often?

There is another concern about the list construction part
in programming.

Although a typical PC is installed with gaga bytes of DRAM
now,  anything that will use more memory from the heap
dynamically could fail in the run time.

It is the programmer's job to identify this kind of sources
in minds.


From as at sci.fi  Sat May 11 11:47:18 2013
From: as at sci.fi (Anssi Saari)
Date: Sat, 11 May 2013 18:47:18 +0300
Subject: Append to python List
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
	<11dfb7f9-9bbb-4e42-bce9-027efffabcf3@googlegroups.com>
	<qottxmccrwi.fsf@ruuvi.it.helsinki.fi>
	<mailman.1551.1368273954.3114.python-list@python.org>
Message-ID: <vg3ip2po6wp.fsf@coffee.modeemi.fi>

Chris Angelico <rosuav at gmail.com> writes:

> On Thu, May 9, 2013 at 9:30 PM, Jussi Piitulainen
> <jpiitula at ling.helsinki.fi> wrote:
>> 88888 Dihedral writes:
>>
>>> This is just the handy style for a non-critical loop.
>>> In a critical loop, the number of  the total operation counts
>>> does matter in the execution speed.
>>
>> Do you use speed often?
>
> Dihedral is a bot. Quite a good one, but a bot.

That's been said often enough. Is the source available and is it in
Python?


From rosuav at gmail.com  Sat May 11 12:00:44 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 12 May 2013 02:00:44 +1000
Subject: Append to python List
In-Reply-To: <vg3ip2po6wp.fsf@coffee.modeemi.fi>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
	<11dfb7f9-9bbb-4e42-bce9-027efffabcf3@googlegroups.com>
	<qottxmccrwi.fsf@ruuvi.it.helsinki.fi>
	<mailman.1551.1368273954.3114.python-list@python.org>
	<vg3ip2po6wp.fsf@coffee.modeemi.fi>
Message-ID: <CAPTjJmqAvmbDE8DZAnmgACMxjoaTPZnvDp0Fo1_6gwS1FMwrTQ@mail.gmail.com>

On Sun, May 12, 2013 at 1:47 AM, Anssi Saari <as at sci.fi> wrote:
> Chris Angelico <rosuav at gmail.com> writes:
>
>> On Thu, May 9, 2013 at 9:30 PM, Jussi Piitulainen
>> <jpiitula at ling.helsinki.fi> wrote:
>>> 88888 Dihedral writes:
>>>
>>>> This is just the handy style for a non-critical loop.
>>>> In a critical loop, the number of  the total operation counts
>>>> does matter in the execution speed.
>>>
>>> Do you use speed often?
>>
>> Dihedral is a bot. Quite a good one, but a bot.
>
> That's been said often enough. Is the source available and is it in
> Python?

Not to my knowledge. Technically Dihedral is merely _rumoured_ to be a
bot, as we have no actual proof; but we've been conducting a variety
of Turing tests via this list and have yet to see any strong argument
for his being deemed human. Most humans would get defensive, or at
least protest, if treated as bots; Dihedral never has, despite being
referred to in this way a number of times.

ChrisA


From dihedral88888 at googlemail.com  Sat May 11 22:29:31 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Sat, 11 May 2013 19:29:31 -0700 (PDT)
Subject: Append to python List
In-Reply-To: <mailman.1558.1368288047.3114.python-list@python.org>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
	<11dfb7f9-9bbb-4e42-bce9-027efffabcf3@googlegroups.com>
	<qottxmccrwi.fsf@ruuvi.it.helsinki.fi>
	<mailman.1551.1368273954.3114.python-list@python.org>
	<vg3ip2po6wp.fsf@coffee.modeemi.fi>
	<mailman.1558.1368288047.3114.python-list@python.org>
Message-ID: <458e28f3-56ad-4fea-87ec-1f1858f5d414@googlegroups.com>

Chris Angelico? 2013?5?12????UTC+8??12?00?44????
> On Sun, May 12, 2013 at 1:47 AM, Anssi Saari <as at sci.fi> wrote:
> 
> > Chris Angelico <rosuav at gmail.com> writes:
> 
> >
> 
> >> On Thu, May 9, 2013 at 9:30 PM, Jussi Piitulainen
> 
> >> <jpiitula at ling.helsinki.fi> wrote:
> 
> >>> 88888 Dihedral writes:
> 
> >>>
> 
> >>>> This is just the handy style for a non-critical loop.
> 
> >>>> In a critical loop, the number of  the total operation counts
> 
> >>>> does matter in the execution speed.
> 
> >>>
> 
> >>> Do you use speed often?
> 
> >>
> 
> >> Dihedral is a bot. Quite a good one, but a bot.
> 
> >
> 
> > That's been said often enough. Is the source available and is it in
> 
> > Python?
> 
> 
> 
> Not to my knowledge. Technically Dihedral is merely _rumoured_ to be a
> 
> bot, as we have no actual proof; but we've been conducting a variety
> 
> of Turing tests via this list and have yet to see any strong argument
> 
> for his being deemed human. Most humans would get defensive, or at
> 
> least protest, if treated as bots; Dihedral never has, despite being
> 
> referred to in this way a number of times.
> 
> 
> 
> ChrisA

Don't you get the practices of   POSIX ?


From rosuav at gmail.com  Sat May 11 22:40:32 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 12 May 2013 12:40:32 +1000
Subject: Append to python List
In-Reply-To: <458e28f3-56ad-4fea-87ec-1f1858f5d414@googlegroups.com>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
	<11dfb7f9-9bbb-4e42-bce9-027efffabcf3@googlegroups.com>
	<qottxmccrwi.fsf@ruuvi.it.helsinki.fi>
	<mailman.1551.1368273954.3114.python-list@python.org>
	<vg3ip2po6wp.fsf@coffee.modeemi.fi>
	<mailman.1558.1368288047.3114.python-list@python.org>
	<458e28f3-56ad-4fea-87ec-1f1858f5d414@googlegroups.com>
Message-ID: <CAPTjJmp4DE9o25w=N+USfHpXZcpPJ_pCy1myurBV476k7pDO=Q@mail.gmail.com>

On Sun, May 12, 2013 at 12:29 PM, 88888 Dihedral
<dihedral88888 at googlemail.com> wrote:
> Chris Angelico? 2013?5?12????UTC+8??12?00?44????
>> Most humans would get defensive, or at
>> least protest, if treated as bots; Dihedral never has, despite being
>> referred to in this way a number of times.
>>
>> ChrisA
>
> Don't you get the practices of   POSIX ?

I rest my case, m'lud.

ChrisA


From jpiitula at ling.helsinki.fi  Sun May 12 02:02:57 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 12 May 2013 09:02:57 +0300
Subject: Append to python List
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<qotobck8wx3.fsf@ruuvi.it.helsinki.fi>
	<11dfb7f9-9bbb-4e42-bce9-027efffabcf3@googlegroups.com>
	<qottxmccrwi.fsf@ruuvi.it.helsinki.fi>
	<mailman.1551.1368273954.3114.python-list@python.org>
Message-ID: <qot8v3kloq6.fsf@ruuvi.it.helsinki.fi>

Chris Angelico writes:
> On Thu, May 9, 2013 at 9:30 PM, Jussi Piitulainen wrote:
> > 88888 Dihedral writes:
> >
> >> This is just the handy style for a non-critical loop.
> >> In a critical loop, the number of  the total operation counts
> >> does matter in the execution speed.
> >
> > Do you use speed often?
> 
> Dihedral is a bot. Quite a good one, but a bot.

Yes, I understood why people say so when it followed up to something I
wrote myself, and what it wrote made no sense in the context. My
response was also generated by a bot: M-x doctor in Emacs, meant to be
funny.

Don't worry, I'm not going to engage it further.


From rosuav at gmail.com  Thu May  9 02:52:42 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 9 May 2013 16:52:42 +1000
Subject: Append to python List
In-Reply-To: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
Message-ID: <CAPTjJmoOFEmpZ5yCpG1L1Wy6Bye-Z7FxdBL_81CgfxbnVybB5w@mail.gmail.com>

On Thu, May 9, 2013 at 4:36 PM, RAHUL RAJ <omrahulrajcse at gmail.com> wrote:
> output=[x for x in sample2 if x not in output]
>
> output=[]
> for x in sample2:
>   if x not in output:
>      output.append(x)

The first one constructs a list, then points the name 'output' at it.
The second one builds up a list, with 'output' pointing at it all the
way. Your first one is more like:

sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]
output=[]
_temp=[]
for x in sample2:
  if x not in output:
     _temp.append(x)
output=_temp

You may want to consider using a set, instead.

>>> {x+y for x in range(1,10) for y in range(1,10) if x!=y}
{3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17}

ChrisA


From gary.herron at islandtraining.com  Thu May  9 02:54:24 2013
From: gary.herron at islandtraining.com (Gary Herron)
Date: Wed, 08 May 2013 23:54:24 -0700
Subject: Append to python List
In-Reply-To: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
Message-ID: <518B4820.40507@islandtraining.com>

On 05/08/2013 11:36 PM, RAHUL RAJ wrote:
> Checkout the following code:
>
> sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]
> output=[]

> output=[x for x in sample2 if x not in output]
This statement is not doing what you expect.  It is not building a list 
in the variable named output, it is building a list (anonymously) then 
binding it to the variable output once it's built.  Therefore output is 
[] for the whole list building operation.

The later operation works, because your *are* building the list in place 
as you go.

>
> the output I get is
> 3 4 5 6 7 8 9 10 3 5 6 7 8 9 10 11 4 5 7 8 9 10 11 12 5 6 7 9 10 11 12 13 6 7 8 9 11 12 13 14 7 8 9 10 11 13 14 15 8 9 10 11 12 13 15 16 9 10 11 12 13 14 15 17 10 11 12 13 14 15 16 17
>
> which contains duplicate values.
>
>
>
>
> But if I do like this:
>
> sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]
> output=[]
> for x in sample2:
>    if x not in output:
>       output.append(x)
>
>
> the value of 'output' I get like this:
> 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
>
> I know that both the programs have the same functionality, but why do I have different outputs?
>
> Please help!



From omrahulrajcse at gmail.com  Thu May  9 04:18:51 2013
From: omrahulrajcse at gmail.com (RAHUL RAJ)
Date: Thu, 9 May 2013 01:18:51 -0700 (PDT)
Subject: Append to python List
In-Reply-To: <mailman.1485.1368082909.3114.python-list@python.org>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<mailman.1485.1368082909.3114.python-list@python.org>
Message-ID: <b8608b36-95f6-40df-a172-b179cb5fd8ee@googlegroups.com>

Then what about this code part?

[(x, y) for x in [1,2,3] for y in [3,1,4] if x != y]

and the following code part:

for x in [1,2,3]:
  for y in [3,1,4]:
    if x != y:
      combs.append((x, y))


On Thursday, May 9, 2013 12:24:24 PM UTC+5:30, Gary Herron wrote:
> On 05/08/2013 11:36 PM, RAHUL RAJ wrote:
> 
> > Checkout the following code:
> 
> >
> 
> > sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]
> 
> > output=[]
> 
> 
> 


> > output=[x for x in sample2 if x not in output]
> 
> This statement is not doing what you expect.  It is not building a list 
> 
> in the variable named output, it is building a list (anonymously) then 
> 
> binding it to the variable output once it's built.  Therefore output is 
> 
> [] for the whole list building operation.
> 
> 
> 
> The later operation works, because your *are* building the list in place 
> 
> as you go.
> 
> 
> 
> >
> 
> > the output I get is
> 
> > 3 4 5 6 7 8 9 10 3 5 6 7 8 9 10 11 4 5 7 8 9 10 11 12 5 6 7 9 10 11 12 13 6 7 8 9 11 12 13 14 7 8 9 10 11 13 14 15 8 9 10 11 12 13 15 16 9 10 11 12 13 14 15 17 10 11 12 13 14 15 16 17
> 
> >
> 
> > which contains duplicate values.
> 
> >
> 
> >
> 
> >
> 
> >
> 
> > But if I do like this:
> 
> >
> 
> > sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]
> 
> > output=[]
> 
> > for x in sample2:
> 
> >    if x not in output:
> 
> >       output.append(x)
> 
> >
> 
> >
> 
> > the value of 'output' I get like this:
> 
> > 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
> 
> >
> 
> > I know that both the programs have the same functionality, but why do I have different outputs?
> 
> >
> 
> > Please help!


From omrahulrajcse at gmail.com  Thu May  9 04:19:43 2013
From: omrahulrajcse at gmail.com (RAHUL RAJ)
Date: Thu, 9 May 2013 01:19:43 -0700 (PDT)
Subject: Append to python List
In-Reply-To: <b8608b36-95f6-40df-a172-b179cb5fd8ee@googlegroups.com>
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<mailman.1485.1368082909.3114.python-list@python.org>
	<b8608b36-95f6-40df-a172-b179cb5fd8ee@googlegroups.com>
Message-ID: <51959fcc-8653-47c0-bc46-b30e82e40f35@googlegroups.com>

I'm getting same output for both code parts, why not for th code parts in question?

On Thursday, May 9, 2013 1:48:51 PM UTC+5:30, RAHUL RAJ wrote:
> Then what about this code part?
> 
> 
> 
> [(x, y) for x in [1,2,3] for y in [3,1,4] if x != y]
> 
> 
> 
> and the following code part:
> 
> 
> 
> for x in [1,2,3]:
> 
>   for y in [3,1,4]:
> 
>     if x != y:
> 
>       combs.append((x, y))
> 
> 
> 
> 
> 
> On Thursday, May 9, 2013 12:24:24 PM UTC+5:30, Gary Herron wrote:
> 
> > On 05/08/2013 11:36 PM, RAHUL RAJ wrote:
> 
> > 
> 
> > > Checkout the following code:
> 
> > 
> 
> > >
> 
> > 
> 
> > > sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]
> 
> > 
> 
> > > output=[]
> 
> > 
> 
> > 
> 
> > 
> 
> 
> 
> 
> 
> > > output=[x for x in sample2 if x not in output]
> 
> > 
> 
> > This statement is not doing what you expect.  It is not building a list 
> 
> > 
> 
> > in the variable named output, it is building a list (anonymously) then 
> 
> > 
> 
> > binding it to the variable output once it's built.  Therefore output is 
> 
> > 
> 
> > [] for the whole list building operation.
> 
> > 
> 
> > 
> 
> > 
> 
> > The later operation works, because your *are* building the list in place 
> 
> > 
> 
> > as you go.
> 
> > 
> 
> > 
> 
> > 
> 
> > >
> 
> > 
> 
> > > the output I get is
> 
> > 
> 
> > > 3 4 5 6 7 8 9 10 3 5 6 7 8 9 10 11 4 5 7 8 9 10 11 12 5 6 7 9 10 11 12 13 6 7 8 9 11 12 13 14 7 8 9 10 11 13 14 15 8 9 10 11 12 13 15 16 9 10 11 12 13 14 15 17 10 11 12 13 14 15 16 17
> 
> > 
> 
> > >
> 
> > 
> 
> > > which contains duplicate values.
> 
> > 
> 
> > >
> 
> > 
> 
> > >
> 
> > 
> 
> > >
> 
> > 
> 
> > >
> 
> > 
> 
> > > But if I do like this:
> 
> > 
> 
> > >
> 
> > 
> 
> > > sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]
> 
> > 
> 
> > > output=[]
> 
> > 
> 
> > > for x in sample2:
> 
> > 
> 
> > >    if x not in output:
> 
> > 
> 
> > >       output.append(x)
> 
> > 
> 
> > >
> 
> > 
> 
> > >
> 
> > 
> 
> > > the value of 'output' I get like this:
> 
> > 
> 
> > > 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
> 
> > 
> 
> > >
> 
> > 
> 
> > > I know that both the programs have the same functionality, but why do I have different outputs?
> 
> > 
> 
> > >
> 
> > 
> 
> > > Please help!



From steve+comp.lang.python at pearwood.info  Thu May  9 07:14:47 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 09 May 2013 11:14:47 GMT
Subject: Append to python List
References: <71427882-d2c6-4066-b1e2-624b12a42a0d@googlegroups.com>
	<mailman.1485.1368082909.3114.python-list@python.org>
	<b8608b36-95f6-40df-a172-b179cb5fd8ee@googlegroups.com>
Message-ID: <518b8527$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Thu, 09 May 2013 01:18:51 -0700, RAHUL RAJ wrote:

> Then what about this code part?


What about it? 


> [(x, y) for x in [1,2,3] for y in [3,1,4] if x != y]
> 
> and the following code part:
> 
> for x in [1,2,3]:
>   for y in [3,1,4]:
>     if x != y:
>       combs.append((x, y))

Apart from not defined combs, those two pieces of code are equivalent.

So what is your question?


-- 
Steven


From kreta06 at gmail.com  Thu May  9 02:59:16 2013
From: kreta06 at gmail.com (kreta06)
Date: Thu, 9 May 2013 08:59:16 +0200
Subject: Forming a small python programming group
Message-ID: <CAAL7fRMAViTUFSf7QA_zTpoo13ykf_udGEoem28Y+wggsQ=f6g@mail.gmail.com>

Hi All,

I'm looking for one or two medium-advanced python programmers to
practice programming on a Windows 7 platform. In addition, any
interests in writing python code to query Microsoft SQL databases
(2005-2008) is also welcomed.

I've coded in python 2.7 and currently am trying to make the switch to
3.2 as there seem to be some changes to the syntax. I'm only available
on a weekend basis and occasionally some week days. Therefore, in
terms of output, probably  2-3 scripts per month. If you are
interested in working with me, please send me an email on similar
interests and we can start this next week.

Best regards,
Sue


From tjreedy at udel.edu  Thu May  9 04:11:55 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Thu, 09 May 2013 04:11:55 -0400
Subject: Forming a small python programming group
In-Reply-To: <CAAL7fRMAViTUFSf7QA_zTpoo13ykf_udGEoem28Y+wggsQ=f6g@mail.gmail.com>
References: <CAAL7fRMAViTUFSf7QA_zTpoo13ykf_udGEoem28Y+wggsQ=f6g@mail.gmail.com>
Message-ID: <kmflo2$r3g$1@ger.gmane.org>

On 5/9/2013 2:59 AM, kreta06 wrote:
> Hi All,
>
> I'm looking for one or two medium-advanced python programmers to
> practice programming on a Windows 7 platform. In addition, any
> interests in writing python code to query Microsoft SQL databases
> (2005-2008) is also welcomed.
>
> I've coded in python 2.7 and currently am trying to make the switch to
> 3.2 as there seem to be some changes to the syntax.

Start with 3.3 unless you *must* use 3.2. There is one less syntax 
change and a better unicode string implementation.





From chandan_psr at yahoo.co.in  Thu May  9 11:35:53 2013
From: chandan_psr at yahoo.co.in (chandan kumar)
Date: Thu, 9 May 2013 23:35:53 +0800 (SGT)
Subject: Urgent:Serial Port Read/Write
Message-ID: <1368113753.5157.YahooMailClassic@web190506.mail.sg3.yahoo.com>

Hi all,I'm new to python and facing issue using serial in python.I'm facing the below error?
? ? ser.write(port,command)NameError: global name 'ser' is not defined
Please find the attached script and let me know whats wrong in my script and also how can i read data from serial port for the ?same script.

Best Regards,Chandan.
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From rosuav at gmail.com  Thu May  9 11:49:05 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 01:49:05 +1000
Subject: Urgent:Serial Port Read/Write
In-Reply-To: <1368113753.5157.YahooMailClassic@web190506.mail.sg3.yahoo.com>
References: <1368113753.5157.YahooMailClassic@web190506.mail.sg3.yahoo.com>
Message-ID: <CAPTjJmrxJowxOE6EAHGikJuoNQcfortPP=mebP0a7a7xne50+g@mail.gmail.com>

On Fri, May 10, 2013 at 1:35 AM, chandan kumar <chandan_psr at yahoo.co.in> wrote:
>
> Hi all,
> I'm new to python and facing issue using serial in python.I'm facing the below error
>
>     ser.write(port,command)
> NameError: global name 'ser' is not defined
>
> Please find the attached script and let me know whats wrong in my script and also how can i read data from serial port for the  same script.

You're assigning to 'ser' inside OpenPort(), but then trying to use it
in WriteSerialData(). You'll need to declare 'global ser' in OpenPort
to make this work.

Alternatively, you may want to cut down on the number of functions you
have, since they're called in only one place anyway and have to share
state.

ChrisA


From fpm at u.washington.edu  Thu May  9 11:44:52 2013
From: fpm at u.washington.edu (Frank Miles)
Date: Thu, 9 May 2013 15:44:52 +0000 (UTC)
Subject: Urgent:Serial Port Read/Write
References: <mailman.1494.1368113767.3114.python-list@python.org>
Message-ID: <kmgg9k$rp5$2@dont-email.me>

On Thu, 09 May 2013 23:35:53 +0800, chandan kumar wrote:

> Hi all,I'm new to python and facing issue using serial in python.I'm
> facing the below error
> ? ? ser.write(port,command)NameError: global name 'ser' is not defined
> Please find the attached script and let me know whats wrong in my script
> and also how can i read data from serial port for the ?same script.
[snip]
> if __name__ == "__main__":
>     
>     CurrDir=os.getcwd()
>     files = glob.glob('./*pyc')
>     for f in files:
>         os.remove(f)
>     OpenPort(26,9600)
>     SetRequest(ER_Address)
>     #SysAPI.SetRequest('ER',ER_Address)
> 
>     print "Test Scripts Execution complete"

What kind of 'port' is 26?  Is that valid on your machine?  My guess is 
that <ser> is NULL (because the open is failing, likely due to the port 
selection), leading to your subsequent problems.

HTH..


From python at mrabarnett.plus.com  Thu May  9 11:54:34 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 09 May 2013 16:54:34 +0100
Subject: Urgent:Serial Port Read/Write
In-Reply-To: <1368113753.5157.YahooMailClassic@web190506.mail.sg3.yahoo.com>
References: <1368113753.5157.YahooMailClassic@web190506.mail.sg3.yahoo.com>
Message-ID: <518BC6BA.3030208@mrabarnett.plus.com>

On 09/05/2013 16:35, chandan kumar wrote:
> Hi all,
> I'm new to python and facing issue using serial in python.I'm facing the
> below error
>
> *    ser.write(port,command)*
> *NameError: global name 'ser' is not defined*
> *
> *
> Please find the attached script and let me know whats wrong in my script
> and also how can i read data from serial port for the  same script.
>
>
> Best Regards,
> Chandan.
>
>
> RunScripts.py
>
>
> import time
> import os
> import serial
> import glob
>
>
> ER_Address = [[0x0A,0x01,0x08,0x99,0xBB,0xBB,0xBB,0xBB,0xBB,0xBB,0xBB]]
> """
> ----------------------------------------------------------------------------------------------------------------------------
> Function Name: RunSequence
> ----------------------------------------------------------------------------------------------------------------------------
> Function Description:
> ---------------------
> A RunSequence function has Multiple calls to the RunSuite function, each call is a single testcase consisting of all the parameters
> required by the RunTesSuite.
> -----------------------------------------------------------------------------------------------------------------------------
> """
> def WriteSerialData(command):

'ser' isn't a local variable (local to this function, that is), nor is
it a global variable (global in this file).

>      ser.write(port,command)
>
> def SendPacket(Packet):
>      str = chr(len(Packet)) + Packet #Concatenation of Packet with the PacketLength
>      print str
>      WriteSerialData(str)
>
>
> def CreateFrame(Edata):

It's more efficient to build a list of the characters and then join
them together into a string in one step than to build the string one
character at a time.

Also, indexing into the list is considered 'unPythonic'; it's much 
simpler to do it this way:

     return chr(0x12) + "".join(chr(d) for d in Edata)

>          evt = chr(0x12)
>          evt = evt + chr(Edata[0])
>          for i in range (1, len(Edata)):
>              evt = evt + chr(Edata[i])
>          return evt
>
> def SetRequest(data):
>      print data
>      new = []
>      new = sum(data, [])
>      Addr = CreateFrame(new)
>      SendPacket(Addr)
>      print "SendPacket Done"
>      ReadPacket()
>
>
> def OpenPort(COMPort,BAUDRATE):
>      """
>      This function reads the serial port and writes it.
>      """
>      comport=COMPort
>      BaudRate=BAUDRATE
>      try:
>          ser = serial.Serial(
>              port=comport,
>              baudrate=BaudRate,
>              bytesize=serial.EIGHTBITS,
>              parity=serial.PARITY_NONE,
>              stopbits=serial.STOPBITS_ONE,
>              timeout=10,
>              xonxoff=0,
>              rtscts=0,
>              dsrdtr=0
>              )
>
>          if ser.isOpen():
>              print "Port Opened"
>              ser.write("Chandan")
>              string1 = ser.read(8)
>              print string1

This function returns either ser ...

>              return ser
>          else:
>              print "Port CLosed"
>              ser.close()

... or 3 ...
>              return 3
>      except serial.serialutil.SerialException:
>          print "Exception"
>          ser.close()
>
... or None!
>
>
>
>
>
> if __name__ == "__main__":
>
>      CurrDir=os.getcwd()
>      files = glob.glob('./*pyc')
>      for f in files:
>          os.remove(f)

OpenPort returns either ser or 3 or None, but the result is just
discarded.

>      OpenPort(26,9600)
>      SetRequest(ER_Address)
>      #SysAPI.SetRequest('ER',ER_Address)
>
>      print "Test Scripts Execution complete"
>



From rosuav at gmail.com  Thu May  9 11:54:48 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 10 May 2013 01:54:48 +1000
Subject: Urgent:Serial Port Read/Write
In-Reply-To: <1368113753.5157.YahooMailClassic@web190506.mail.sg3.yahoo.com>
References: <1368113753.5157.YahooMailClassic@web190506.mail.sg3.yahoo.com>
Message-ID: <CAPTjJmq5owazqLD2ctvvv=u88YyZRAdTJpbfpq5Ysrde3k6P5Q@mail.gmail.com>

On Fri, May 10, 2013 at 1:35 AM, chandan kumar <chandan_psr at yahoo.co.in> wrote:
> Please find the attached script and let me know whats wrong in my script
> and also how can i read data from serial port for the  same script.

Don't do this:

    except serial.serialutil.SerialException:
        print "Exception"
        ser.close()

Just let it propagate up and show you a traceback. There is absolutely
no value in suppressing an exception only to print an unhelpful
message.

ChrisA


From tavares at fe.up.pt  Thu May  9 13:27:23 2013
From: tavares at fe.up.pt (tavares at fe.up.pt)
Date: Thu, 9 May 2013 10:27:23 -0700 (PDT)
Subject: IV ECCOMAS Thematic Conference VipIMAGE 2013: LAST CALL
Message-ID: <f0907b9b-6a1a-4f9c-b743-30e8816e4637@googlegroups.com>

Dear Colleague,

Attending several requests, the organizing committee has extended the submission of abstracts for the International Conference VipIMAGE 2013 - IV ECCOMAS THEMATIC CONFERENCE ON COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING (www.fe.up.pt/~vipimage) to be held October 14-16, 2013, in Melia Madeira Mare Hotel, Madeira Island, Funchal, Portugal, to May 20th.

Possible Topics (not limited to)

? Signal and Image Processing 
? Computational Vision 
? Medical Imaging 
? Physics of Medical Imaging 
? Tracking and Analysis of Movement 
? Simulation and Modeling
? Image Acquisition 
? Industrial Applications 
? Shape Reconstruction 
? Objects Segmentation, Matching, Simulation 
? Data Interpolation, Registration, Acquisition and Compression 
? 3D Vision 
? Virtual Reality 
? Visual Inspection 
? Software Development for Image Processing and Analysis 
? Computer Aided Diagnosis, Surgery, Therapy, and Treatment 
? Computational Bioimaging and Visualization 
? Telemedicine Systems and their Applications

Invited Lecturers

? Daniel Rueckert - Imperial College London, UK
? Dimitris N. Metaxas - Rutgers University, USA
? Durval C. Costa - Champalimaud Foundation, Portugal
? James S Duncan - Yale School of Medicine, USA
? Milan Sonka - The University of Iowa, USA
? Richard Bowden - University of Surrey, UK

Thematic Sessions

Proposals to organize Thematic Session under the auspicious of VipIMAGE 2013 are welcome.
The proposals should be submitted by email to the conference co-chairs (tavares at fe.up.pt, rnatal at fe.up.pt).

Confirmed Thematic Sessions

? Imaging of Biological Flows: trends and challenges
? Trabecular Bone Characterization: New trends and challenges
? Computational Vision and Image Processing applied to Dental Medicine

Publications

? Proceedings: The proceedings book will be published by the Taylor & Francis Group (www.balkema.nl/instructions.asp) and indexed by Thomson Reuters Conference Proceedings Citation Index, IET Inspect and Elsevier Scopus.
? Springer Book: A book with 20 invited works from the ones presented in the conference will be published by Springer under the book series ?Lecture Notes in Computational Vision and Biomechanics? (www.springer.com/series/8910).
? Journal Publication: A dedicated special issue of the Taylor & Francis International Journal ?Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization? (www.tandfonline.com/tciv) will be published with extended versions of the best works presented in the conference.

Important dates

? Deadline for (2-4 pages) Abstracts: May 20, 2013 (LAST POSTPONED)
? Authors Notification: June 10, 2013
? Deadline to upload Lectures and Papers: July 1, 2013


We are looking forward to see you in Funchal next October.

Kind regards,

Jo?o Manuel R. S. Tavares
Renato Natal Jorge
(conference co-chairs)

PS. For further details, please, have a look in the conference website at: www.fe.up.pt/~vipimage, or in the conference Facebook page at: www.facebook.com/pages/Vipimage/237980719665456, or join the LinkedIn conference group at: http://www.linkedin.com/groups?gid=4752820&trk=hb_side_g


From demianbrecht at gmail.com  Thu May  9 19:07:52 2013
From: demianbrecht at gmail.com (Demian Brecht)
Date: Thu, 9 May 2013 16:07:52 -0700
Subject: [ANN] flask-canvas
Message-ID: <CAE+T62YAQrfwLpn2t91GYG+7ORKtsRKzwX+_=v8FskRucnPnRg@mail.gmail.com>

A Flask extension for Facebook canvas-based applications.

https://github.com/demianbrecht/flask-canvas

Docs available on RTD: https://flask-canvas.readthedocs.org/en/latest/

--
Demian Brecht
http://demianbrecht.github.com


From yanxiaopei199 at gmail.com  Thu May  9 22:33:20 2013
From: yanxiaopei199 at gmail.com (Thanatos xiao)
Date: Fri, 10 May 2013 10:33:20 +0800
Subject: python call golang
Message-ID: <CAF0POcsGa=qseuQETxRz=vmazvMmNN+U5nLC43_aX1VNaJmUKQ@mail.gmail.com>

Hey !

Now! I have written a python script . I want to call a golang script in
python script.
Who can give me some advices?

thanks!
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From fabiosantosart at gmail.com  Fri May 10 03:01:32 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Fri, 10 May 2013 08:01:32 +0100
Subject: python call golang
In-Reply-To: <CAF0POcsGa=qseuQETxRz=vmazvMmNN+U5nLC43_aX1VNaJmUKQ@mail.gmail.com>
References: <CAF0POcsGa=qseuQETxRz=vmazvMmNN+U5nLC43_aX1VNaJmUKQ@mail.gmail.com>
Message-ID: <CAA=1kxSS1+xSyXrUkiYztEm6THpbJK7TP002fvV=CSJBdagzdQ@mail.gmail.com>

On 10 May 2013 03:37, "Thanatos xiao" <yanxiaopei199 at gmail.com> wrote:
>
> Hey !
>
> Now! I have written a python script . I want to call a golang script in
python script.
> Who can give me some advices?
>
> thanks!

Check out the subprocess module. You can use it to call other programs from
python and get their error codes and output.
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From miki.tebeka at gmail.com  Fri May 10 18:21:29 2013
From: miki.tebeka at gmail.com (Miki Tebeka)
Date: Fri, 10 May 2013 15:21:29 -0700 (PDT)
Subject: python call golang
In-Reply-To: <mailman.1516.1368153201.3114.python-list@python.org>
References: <mailman.1516.1368153201.3114.python-list@python.org>
Message-ID: <c3a96894-08b0-46bc-a1ee-d8aad9634ec3@googlegroups.com>


> Now! I have written a python script . I want to call a golang script in python script.
> Who can give me some advices?
See http://gopy.qur.me/extensions/examples.html and http://www.artima.com/weblogs/viewpost.jsp?thread=333589


From bv8bv8bv8 at gmail.com  Fri May 10 15:44:59 2013
From: bv8bv8bv8 at gmail.com (BV BV)
Date: Fri, 10 May 2013 12:44:59 -0700 (PDT)
Subject: ?????????? WHY DID PROPHET MUHAMMAD MARRY AISHA THE YOUNG GIRL
Message-ID: <969305c6-aa72-41ec-b889-2e2b2d4b28e8@gm7g2000vbb.googlegroups.com>

WHY DID PROPHET MUHAMMAD MARRY AISHA THE YOUNG GIRL?

This is an important book talks about a common issue misunderstood but
misused by lots of thinkers and orientalists. It is ?Why did Prophet
Muhammad marry Aisha the young girl?? The author shows the reason
behind their discussion. They want to distort the picture of Prophet
Muhammad not criticize the marriage of young girl. Also if this kind
of marriage was strange, why did not the disbelievers of Quraish use
it as a pretext against Muhammad?! The author discusses other topics
such as: Europe also allows marrying young girls, the age of consent
in most countries worldwide.

http://www.islamhouse.com/330161/en/en/books/Why_Did_Prophet_Muhammad_Marry_Aisha_the_Young_Girl?

thank you


From francis.brosnan at gmail.com  Sat May 11 14:23:55 2013
From: francis.brosnan at gmail.com (francis.brosnan at gmail.com)
Date: Sat, 11 May 2013 11:23:55 -0700 (PDT)
Subject: Right way to initialize python embedded in a multi-threaded
	application
In-Reply-To: <19ed5abe-7283-4dad-bd8f-b5209b3d974b@3g2000vbx.googlegroups.com>
References: <19ed5abe-7283-4dad-bd8f-b5209b3d974b@3g2000vbx.googlegroups.com>
Message-ID: <0edf6083-4f49-4a6e-834a-7d5fd1f0c774@googlegroups.com>

Hi,

Maybe you already fixed the issue, but for the record, I've got the same
problem and finally it turned out that I was calling PyEval_InitThreads twice
and also after fixing that, I also had to move the call to PyEval_ReleaseLock();  at the end of the entire initialization (not just after PyEval_initThreads).

The key thing there is to follow:

<<at initialization thread>>
Py_Initialize ();
PyEval_InitThreads(); 
/* now call here to initialize all python code by loading external files 
   or internal module loading (i.e. Py_InitModule3) */
/* ..and now, once no more Python C/API call is required, release
   the GIL so other threads can come into play */
PyEval_ReleaseLock ();

<<and now, from other threads, use>>
/* wait til gil acquired */
state  = PyGILState_Ensure();
/* your code */
/* release GIL */
PyGILState_Release (state);

Hope it helps, Cheers!


> I'm embedding python in a multi-threaded C application.
> 
> I've taken care to wrap every call to the Python C API with
> 
> 
> 
> gstate = PyGILState_Ensure();
> 
> // call python code
> 
> PyGILState_Release(gstate);
> 
> 
> 
> But I'm stumped with what to do in the initialization.
> 
> Right after the call to Py_IsInitialized() I've added a call:
> 
> 
> 
> PyEval_InitThreads();
> 
> 
> 
> The docs say that this function leaves the GIL locked when it returns.
> 
> I do some more initializations like importing modules and then I call
> 
> 
> 
> PyEval_ReleaseLock();
> 
> 
> 
> This seems to cause a problem since not long after a call to
> 
> PyGILState_Release(gstate) that's made in a different thread crashes.
> 
> with
> 
> 
> 
> "Fatal Python error: This thread state must be current when releasing"
> 
> 
> 
> If I don't do the call to PyEval_ReleaseLock() in the main thread
> 
> right after initialization, the GIL seems to be released
> 
> after the first PyGILState_Ensure() - PyGILState_Release() pair.
> 
> 
> 
> So what am I doing wrong here?
> 
> What is the correct way of initializing a multi-threaded application?


From francis.brosnan at gmail.com  Sat May 11 16:00:44 2013
From: francis.brosnan at gmail.com (francis.brosnan at gmail.com)
Date: Sat, 11 May 2013 13:00:44 -0700 (PDT)
Subject: Right way to initialize python embedded in a multi-threaded
	application
In-Reply-To: <0edf6083-4f49-4a6e-834a-7d5fd1f0c774@googlegroups.com>
References: <19ed5abe-7283-4dad-bd8f-b5209b3d974b@3g2000vbx.googlegroups.com>
	<0edf6083-4f49-4a6e-834a-7d5fd1f0c774@googlegroups.com>
Message-ID: <c7c3b937-0188-4557-b5af-640966224218@googlegroups.com>

Just clarify there's no problem about calling twice to PyEval_InitThreads ()
as indicated by Python's doc.

> Hi,
> 
> 
> 
> Maybe you already fixed the issue, but for the record, I've got the same
> 
> problem and finally it turned out that I was calling PyEval_InitThreads twice
> 
> and also after fixing that, I also had to move the call to PyEval_ReleaseLock();  at the end of the entire initialization (not just after PyEval_initThreads).
> 
> 
> 
> The key thing there is to follow:
> 
> 
> 
> <<at initialization thread>>
> 
> Py_Initialize ();
> 
> PyEval_InitThreads(); 
> 
> /* now call here to initialize all python code by loading external files 
> 
>    or internal module loading (i.e. Py_InitModule3) */
> 
> /* ..and now, once no more Python C/API call is required, release
> 
>    the GIL so other threads can come into play */
> 
> PyEval_ReleaseLock ();
> 
> 
> 
> <<and now, from other threads, use>>
> 
> /* wait til gil acquired */
> 
> state  = PyGILState_Ensure();
> 
> /* your code */
> 
> /* release GIL */
> 
> PyGILState_Release (state);
> 
> 
> 
> Hope it helps, Cheers!
> 
> 
> 
> 
> 
> > I'm embedding python in a multi-threaded C application.
> 
> > 
> 
> > I've taken care to wrap every call to the Python C API with
> 
> > 
> 
> > 
> 
> > 
> 
> > gstate = PyGILState_Ensure();
> 
> > 
> 
> > // call python code
> 
> > 
> 
> > PyGILState_Release(gstate);
> 
> > 
> 
> > 
> 
> > 
> 
> > But I'm stumped with what to do in the initialization.
> 
> > 
> 
> > Right after the call to Py_IsInitialized() I've added a call:
> 
> > 
> 
> > 
> 
> > 
> 
> > PyEval_InitThreads();
> 
> > 
> 
> > 
> 
> > 
> 
> > The docs say that this function leaves the GIL locked when it returns.
> 
> > 
> 
> > I do some more initializations like importing modules and then I call
> 
> > 
> 
> > 
> 
> > 
> 
> > PyEval_ReleaseLock();
> 
> > 
> 
> > 
> 
> > 
> 
> > This seems to cause a problem since not long after a call to
> 
> > 
> 
> > PyGILState_Release(gstate) that's made in a different thread crashes.
> 
> > 
> 
> > with
> 
> > 
> 
> > 
> 
> > 
> 
> > "Fatal Python error: This thread state must be current when releasing"
> 
> > 
> 
> > 
> 
> > 
> 
> > If I don't do the call to PyEval_ReleaseLock() in the main thread
> 
> > 
> 
> > right after initialization, the GIL seems to be released
> 
> > 
> 
> > after the first PyGILState_Ensure() - PyGILState_Release() pair.
> 
> > 
> 
> > 
> 
> > 
> 
> > So what am I doing wrong here?
> 
> > 
> 
> > What is the correct way of initializing a multi-threaded application?


From citizenkant at gmail.com  Sat May 11 16:03:15 2013
From: citizenkant at gmail.com (Citizen Kant)
Date: Sat, 11 May 2013 22:03:15 +0200
Subject: Python for philosophers
Message-ID: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>

Hi,
this could be seen as an extravagant subject but that is not my original
purpose. I still don't know if I want to become a programmer or not. At
this moment I'm just inspecting the environment. I'm making my way to
Python (and OOP in general) from a philosophical perspective or point of
view and try to set the more global definition of Python's core as an
"entity". In order to do that, and following Wittgenstein's indication
about that the true meaning of words doesn't reside on dictionaries but in
the use that we make of them, the starting question I make to myself about
Python is: which is the single and most basic use of Python as the entity
it is? I mean, beside programming, what's the single and most basic result
one can expect from "interacting" with it directly (interactive mode)? I
roughly came to the idea that Python could be considered as an *economic
mirror for data*, one that mainly *mirrors* the data the programmer types
on its black surface, not exactly as the programmer originally typed it,
but expressed in the most economic way possible. That's to say, for
example, if one types >>>1+1 Python reflects >>>2. When data appears
between apostrophes, then the mirror reflects, again, the same but
expressed in the most economic way possible (that's to say without the
apostrophes).

So, would it be legal (true) to define Python's core as an entity that
mirrors whatever data one presents to it (or feed it with) showing back the
most shortened expression of that data?

Don't get me wrong. I can see the big picture and the amazing things that
programmers write on Python, it's just that my question points to the
lowest level of it's existence.

Thanks a lot for your time.
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From dreamingforward at gmail.com  Sat May 11 16:10:45 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Sat, 11 May 2013 13:10:45 -0700
Subject: Python for philosophers
In-Reply-To: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
Message-ID: <CAMjeLr9TTUXJQxwe5=N3U4adjUe3-Mj0UHmW97vJZx7aJNGM1A@mail.gmail.com>

On Sat, May 11, 2013 at 1:03 PM, Citizen Kant <citizenkant at gmail.com> wrote:
>[...] the starting question I make to myself about Python is: which is the single
> and most basic use of Python as the entity it is? I mean, beside
> programming, what's the single and most basic result one can expect from
> "interacting" with it directly (interactive mode)? I roughly came to the
> idea that Python could be considered as an economic mirror for data, one
> that mainly mirrors the data the programmer types on its black surface, not
> exactly as the programmer originally typed it, but expressed in the most
> economic way possible. That's to say, for example, if one types >>>1+1
> Python reflects >>>2. When data appears between apostrophes, then the mirror
> reflects, again, the same but expressed in the most economic way possible
> (that's to say without the apostrophes).

Wow.  You must be from another planet.  Find Socrates if you wish to
know these things.  He's from there also.

A-dam.


From fabiosantosart at gmail.com  Sat May 11 16:21:47 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sat, 11 May 2013 21:21:47 +0100
Subject: Python for philosophers
In-Reply-To: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
Message-ID: <CAA=1kxTY9kY8-KG5Z1hKpSEQ1t-kaya3ZLykras9wc7zk37HoQ@mail.gmail.com>

On 11 May 2013 21:07, "Citizen Kant" <citizenkant at gmail.com> wrote:
>
> Hi,
> this could be seen as an extravagant subject but that is not my original
purpose. I still don't know if I want to become a programmer or not. At
this moment I'm just inspecting the environment. I'm making my way to
Python (and OOP in general) from a philosophical perspective or point of
view and try to set the more global definition of Python's core as an
"entity". In order to do that, and following Wittgenstein's indication
about that the true meaning of words doesn't reside on dictionaries but in
the use that we make of them, the starting question I make to myself about
Python is: which is the single and most basic use of Python as the entity
it is? I mean, beside programming, what's the single and most basic result
one can expect from "interacting" with it directly (interactive mode)? I
roughly came to the idea that Python could be considered as an economic
mirror for data, one that mainly mirrors the data the programmer types on
its black surface, not exactly as the programmer originally typed it, but
expressed in the most economic way possible. That's to say, for example, if
one types >>>1+1 Python reflects >>>2. When data appears between
apostrophes, then the mirror reflects, again, the same but expressed in the
most economic way possible (that's to say without the apostrophes).
>
> So, would it be legal (true) to define Python's core as an entity that
mirrors whatever data one presents to it (or feed it with) showing back the
most shortened expression of that data?
>
> Don't get me wrong. I can see the big picture and the amazing things that
programmers write on Python, it's just that my question points to the
lowest level of it's existence.
>
> Thanks a lot for your time.
>

I can't tell if you are being sarcastic but I'll reply anyway. Python does
not necessarily shorten data. The Python machine is the house for your
representations of data, your own "mirrors".

When you program you are asking python to acknowledge your representations
and to do work on them as you specify. Both of these tasks are expressed in
code. The first is the simplest, where you create your classes. It is
optional since you may use no classes at all and instead use files, text
and numbers, or classes given by someone else. The second is where you give
the orders and lay a script (as in a movie script, or a game script) out.
You can create and command many representations of data in order to make
your program fulfill its purpose. You can also make choices according to
the current state of your data.
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From wuwei23 at gmail.com  Sat May 11 18:16:04 2013
From: wuwei23 at gmail.com (alex23)
Date: Sat, 11 May 2013 15:16:04 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1567.1368303052.3114.python-list@python.org>
Message-ID: <af5ca518-1732-440c-b70c-870e9c5a43ff@wg15g2000pbb.googlegroups.com>

On 12 May, 06:10, Mark Janssen <dreamingforw... at gmail.com> wrote:
> Wow. ?You must be from another planet. ?Find Socrates if you wish to
> know these things. ?He's from there also.

Now now, there's no need for a turf war, there's plenty of room on
this list for crazies.



From rustompmody at gmail.com  Sun May 12 00:22:11 2013
From: rustompmody at gmail.com (rusi)
Date: Sat, 11 May 2013 21:22:11 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1567.1368303052.3114.python-list@python.org>
	<af5ca518-1732-440c-b70c-870e9c5a43ff@wg15g2000pbb.googlegroups.com>
Message-ID: <3ecb79eb-4b62-4da9-bdaa-a8d4f8d008c3@zo5g2000pbb.googlegroups.com>

On May 12, 3:16?am, alex23 <wuwe... at gmail.com> wrote:
> On 12 May, 06:10, Mark Janssen <dreamingforw... at gmail.com> wrote:
>
> > Wow. ?You must be from another planet. ?Find Socrates if you wish to
> > know these things. ?He's from there also.
>
> Now now, there's no need for a turf war, there's plenty of room on
> this list for crazies.

I'm reminded of this:

Conversation between inmate and attendant in an asylum

Inmate: I am Napoleon
Attendant: Yes of course. But how did you know that?
Inmate: God himself told me s?
[Loud voice from another corner] I told you no such thing!


From rosuav at gmail.com  Sun May 12 00:47:45 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 12 May 2013 14:47:45 +1000
Subject: Python for philosophers
In-Reply-To: <3ecb79eb-4b62-4da9-bdaa-a8d4f8d008c3@zo5g2000pbb.googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1567.1368303052.3114.python-list@python.org>
	<af5ca518-1732-440c-b70c-870e9c5a43ff@wg15g2000pbb.googlegroups.com>
	<3ecb79eb-4b62-4da9-bdaa-a8d4f8d008c3@zo5g2000pbb.googlegroups.com>
Message-ID: <CAPTjJmo4LuZtitCUNLhjoS17tBBdzO1eRn3teVu5LwL7QG1iRw@mail.gmail.com>

On Sun, May 12, 2013 at 2:22 PM, rusi <rustompmody at gmail.com> wrote:
> On May 12, 3:16 am, alex23 <wuwe... at gmail.com> wrote:
>> On 12 May, 06:10, Mark Janssen <dreamingforw... at gmail.com> wrote:
>>
>> > Wow.  You must be from another planet.  Find Socrates if you wish to
>> > know these things.  He's from there also.
>>
>> Now now, there's no need for a turf war, there's plenty of room on
>> this list for crazies.
>
> I'm reminded of this:
>
> Conversation between inmate and attendant in an asylum
>
> Inmate: I am Napoleon
> Attendant: Yes of course. But how did you know that?
> Inmate: God himself told me s?
> [Loud voice from another corner] I told you no such thing!

Who's been telling you of private conversations between Steven and me?

ChrisA


From rustompmody at gmail.com  Sun May 12 00:45:12 2013
From: rustompmody at gmail.com (rusi)
Date: Sat, 11 May 2013 21:45:12 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1567.1368303052.3114.python-list@python.org>
	<af5ca518-1732-440c-b70c-870e9c5a43ff@wg15g2000pbb.googlegroups.com>
	<3ecb79eb-4b62-4da9-bdaa-a8d4f8d008c3@zo5g2000pbb.googlegroups.com>
Message-ID: <d49ba45f-491b-478b-8ccb-e1701c4bf081@ua8g2000pbb.googlegroups.com>

On May 12, 9:22?am, rusi <rustompm... at gmail.com> wrote:
> On May 12, 3:16?am, alex23 <wuwe... at gmail.com> wrote:
>
> > On 12 May, 06:10, Mark Janssen <dreamingforw... at gmail.com> wrote:
>
> > > Wow. ?You must be from another planet. ?Find Socrates if you wish to
> > > know these things. ?He's from there also.
>
> > Now now, there's no need for a turf war, there's plenty of room on
> > this list for crazies.
>
> I'm reminded of this:
>
> Conversation between inmate and attendant in an asylum
>
> Inmate: I am Napoleon
> Attendant: Yes of course. But how did you know that?
> Inmate: God himself told me s?
> [Loud voice from another corner] I told you no such thing!

I have on occasion expressed that newcomers to this list should be
treated with more gentleness than others.
And since my own joking may be taken amiss, let me hasten to add (to
the OP -- Citizen Kant)

What you are looking for is more in line with what is called
'rewriting systems'
And the shortening you talk of is usually called 'canonical form' or
'normal form'

Python is closer to such than traditional imperative/OO languages like
C/C++/Java, though other languages -- usually called 'functional
language' are generally closer to this ideal.

The most mainstream of these today is probably 'Haskell'
For your purposes however you may want to look at functional languages
that are more explicitly based on rewriting such as 'Pure' (earlier
'Q')

For last http://en.wikipedia.org/wiki/Pure_%28programming_language%29

For rest: Ive tried to put into quotes things that could he helpful
starting points for search engine research


From steve+comp.lang.python at pearwood.info  Sun May 12 01:17:57 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 12 May 2013 05:17:57 GMT
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1567.1368303052.3114.python-list@python.org>
	<af5ca518-1732-440c-b70c-870e9c5a43ff@wg15g2000pbb.googlegroups.com>
	<3ecb79eb-4b62-4da9-bdaa-a8d4f8d008c3@zo5g2000pbb.googlegroups.com>
	<d49ba45f-491b-478b-8ccb-e1701c4bf081@ua8g2000pbb.googlegroups.com>
Message-ID: <518f2605$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sat, 11 May 2013 21:45:12 -0700, rusi wrote:

> I have on occasion expressed that newcomers to this list should be
> treated with more gentleness than others. And since my own joking may be
> taken amiss, let me hasten to add (to the OP -- Citizen Kant)

A noble aim, but I have a feeling that "Citizen Kant" is version 2.0 of 
88888 Dihedral.

Of course, I could be wrong.


-- 
Steven


From jeanpierreda at gmail.com  Sun May 12 04:15:30 2013
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Sun, 12 May 2013 04:15:30 -0400
Subject: Python for philosophers
In-Reply-To: <518f2605$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1567.1368303052.3114.python-list@python.org>
	<af5ca518-1732-440c-b70c-870e9c5a43ff@wg15g2000pbb.googlegroups.com>
	<3ecb79eb-4b62-4da9-bdaa-a8d4f8d008c3@zo5g2000pbb.googlegroups.com>
	<d49ba45f-491b-478b-8ccb-e1701c4bf081@ua8g2000pbb.googlegroups.com>
	<518f2605$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CABicbJJ5dajkCdxSbmpRR7fyC_4nGk2Lzgzxn=uBWFR00ho=mw@mail.gmail.com>

On Sun, May 12, 2013 at 1:17 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Sat, 11 May 2013 21:45:12 -0700, rusi wrote:
>
>> I have on occasion expressed that newcomers to this list should be
>> treated with more gentleness than others. And since my own joking may be
>> taken amiss, let me hasten to add (to the OP -- Citizen Kant)
>
> A noble aim, but I have a feeling that "Citizen Kant" is version 2.0 of
> 88888 Dihedral.
>
> Of course, I could be wrong.

Without benefit of the doubt, kindness is impossible. I would suggest
giving newcomers at least that much.

-- Devin


From steve+comp.lang.python at pearwood.info  Sun May 12 10:32:07 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 12 May 2013 14:32:07 GMT
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1567.1368303052.3114.python-list@python.org>
	<af5ca518-1732-440c-b70c-870e9c5a43ff@wg15g2000pbb.googlegroups.com>
	<3ecb79eb-4b62-4da9-bdaa-a8d4f8d008c3@zo5g2000pbb.googlegroups.com>
	<d49ba45f-491b-478b-8ccb-e1701c4bf081@ua8g2000pbb.googlegroups.com>
	<518f2605$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1579.1368346574.3114.python-list@python.org>
Message-ID: <518fa7e7$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sun, 12 May 2013 04:15:30 -0400, Devin Jeanpierre wrote:

> On Sun, May 12, 2013 at 1:17 AM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> On Sat, 11 May 2013 21:45:12 -0700, rusi wrote:
>>
>>> I have on occasion expressed that newcomers to this list should be
>>> treated with more gentleness than others. And since my own joking may
>>> be taken amiss, let me hasten to add (to the OP -- Citizen Kant)
>>
>> A noble aim, but I have a feeling that "Citizen Kant" is version 2.0 of
>> 88888 Dihedral.
>>
>> Of course, I could be wrong.
> 
> Without benefit of the doubt, kindness is impossible.

That is a logical non sequitor. One can choose to be kind to someone even 
if you have no doubt that they do not deserve it.

Besides, kindness is hard to define. Is it kinder to give somebody what 
they want, or what they need?

> I would suggest giving newcomers at least that much.

I'm happy to say that, based on Citizen Kant's second post, I'm now 
reasonably confident that (s)he is not a bot. No mere artificial 
intelligence could have written that second post.



-- 
Steven


From greg.ewing at canterbury.ac.nz  Sat May 11 21:26:02 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sun, 12 May 2013 13:26:02 +1200
Subject: Python for philosophers
In-Reply-To: <mailman.1566.1368302603.3114.python-list@python.org>
References: <mailman.1566.1368302603.3114.python-list@python.org>
Message-ID: <av89dcFbgncU1@mid.individual.net>

Citizen Kant wrote:
> I roughly came to the idea that Python could be 
> considered as an *economic mirror for data*, one that mainly *mirrors* 
> the data the programmer types on its black surface, not exactly as the 
> programmer originally typed it, but expressed in the most economic way 
> possible.

At best, this would be true only for a very small
subset of things that you can enter into the
interactive interpreter.

Even confining yourself to arithmetic expressions,
there are problems. Consider:

 >>> 12**34
4922235242952026704037113243122008064L

The input is 6 characters long, and the output
is 37 characters long. Is that more "economical"?

-- 
Greg


From steve+comp.lang.python at pearwood.info  Sun May 12 22:46:59 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 13 May 2013 02:46:59 GMT
Subject: Python for philosophers
References: <mailman.1566.1368302603.3114.python-list@python.org>
Message-ID: <51905423$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sat, 11 May 2013 22:03:15 +0200, Citizen Kant wrote:

> Hi,
> this could be seen as an extravagant subject but that is not my original
> purpose. I still don't know if I want to become a programmer or not. At
> this moment I'm just inspecting the environment.

Towards what purpose?

Do you want to learn to program? If not, then why do you care about 
Python programming? What do you aim to get out of this exercise?


> I'm making my way to
> Python (and OOP in general) from a philosophical perspective or point of
> view and try to set the more global definition of Python's core as an
> "entity". 

What do you think "Python's core" means? What do you mean by "global 
definition"? What is an "entity"?


> In order to do that, and following Wittgenstein's indication
> about that the true meaning of words doesn't reside on dictionaries but
> in the use that we make of them, the starting question I make to myself
> about Python is: which is the single and most basic use of Python as the
> entity it is? 

Programming.

A programming language is an abstract system for performing computations. 
Or, if you prefer simple English, programming. Programming is what 
programming languages are for. That is *all* they are for.


> I mean, beside programming, 

Your question pre-supposes a counter-factual. Namely that there exists 
something *more fundamental* to programming that Python is for. One might 
as well ask:

"Aside from driving screws, what is the single and most basic use of a 
screwdriver?"

Just because you can pound a small nail into soft wood using the handle 
of a screwdriver, does not mean that pounding nails is more fundamental 
to the screwdriver than driving screws.


> what's the single and most
> basic result one can expect from "interacting" with it directly
> (interactive mode)? 

For your purposes, what is so special about interactive mode that you 
single it out in this way? Interactive mode is just like non-interactive 
mode, only the user interacts directly with the compiler, instead of 
indirectly.


-- 
Steven


From maniandram01 at gmail.com  Tue May 14 23:51:44 2013
From: maniandram01 at gmail.com (Ramchandra Apte)
Date: Tue, 14 May 2013 20:51:44 -0700 (PDT)
Subject: Python for philosophers
In-Reply-To: <mailman.1566.1368302603.3114.python-list@python.org>
References: <mailman.1566.1368302603.3114.python-list@python.org>
Message-ID: <5f0543e3-7e26-42fa-a5dc-f4319d23da4e@googlegroups.com>

On Sunday, 12 May 2013 01:33:15 UTC+5:30, Citizen Kant  wrote:
> Hi,
> this could be seen as an extravagant subject but that is not my original purpose. I still don't know if I want to become a programmer or not. At this moment I'm just inspecting the environment. I'm making my way to Python (and OOP in general) from a philosophical perspective or point of view and try to set the more global definition of Python's core as an "entity". In order to do that, and following Wittgenstein's indication about that the true meaning of words doesn't reside on dictionaries but in the use that we make of them, the starting question I make to myself about Python is: which is the single and most basic use of Python as the entity it is? I mean, beside programming, what's the single and most basic result one can expect from "interacting" with it directly (interactive mode)? I roughly came to the idea that Python could be considered as an economic mirror for data, one that mainly mirrors the data the programmer types on its black surface, not exactly as the programmer originally typed it, but expressed in the most economic way possible. That's to say, for example, if one types >>>1+1 Python reflects >>>2. When data appears between apostrophes, then the mirror reflects, again, the same but expressed in the most economic way possible (that's to say without the apostrophes).
> So, would it be legal (true) to define Python's core as an entity that mirrors whatever data one presents to it (or feed it with) showing back the most shortened expression of that data?
> Don't get me wrong. I can see the big picture and the amazing things that programmers write on Python, it's just that my question points to the lowest level of it's existence.
> Thanks a lot for your time.
I expected some spam but this actually makes some sense.



From ned at nedbatchelder.com  Sat May 11 22:46:38 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Sat, 11 May 2013 22:46:38 -0400
Subject: Python for philosophers
In-Reply-To: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
Message-ID: <518F028E.4080102@nedbatchelder.com>


On 5/11/2013 4:03 PM, Citizen Kant wrote:
> Hi,
> this could be seen as an extravagant subject but that is not my 
> original purpose. I still don't know if I want to become a programmer 
> or not. At this moment I'm just inspecting the environment. I'm making 
> my way to Python (and OOP in general) from a philosophical perspective 
> or point of view and try to set the more global definition of Python's 
> core as an "entity". In order to do that, and following Wittgenstein's 
> indication about that the true meaning of words doesn't reside on 
> dictionaries but in the use that we make of them, the starting 
> question I make to myself about Python is: which is the single and 
> most basic use of Python as the entity it is? I mean, beside 
> programming, what's the single and most basic result one can expect 
> from "interacting" with it directly (interactive mode)? I roughly came 
> to the idea that Python could be considered as an *economic mirror for 
> data*, one that mainly *mirrors* the data the programmer types on its 
> black surface, not exactly as the programmer originally typed it, but 
> expressed in the most economic way possible. That's to say, for 
> example, if one types >>>1+1 Python reflects >>>2. When data appears 
> between apostrophes, then the mirror reflects, again, the same but 
> expressed in the most economic way possible (that's to say without the 
> apostrophes).
>
> So, would it be legal (true) to define Python's core as an entity that 
> mirrors whatever data one presents to it (or feed it with) showing 
> back the most shortened expression of that data?
>
> Don't get me wrong. I can see the big picture and the amazing things 
> that programmers write on Python, it's just that my question points to 
> the lowest level of it's existence.
>
> Thanks a lot for your time.
>
>

Python is straightforward: you write instructions, and it executes 
them.  At its core, that's all it does.  Why does the core have to be 
any different than that?

--Ned.
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From joel.goldstick at gmail.com  Sat May 11 23:14:19 2013
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Sat, 11 May 2013 23:14:19 -0400
Subject: Python for philosophers
In-Reply-To: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
Message-ID: <CAPM-O+zJ8N0aCkKAq6qQ=A8HpDghpb1__Ln6uyO5xU4T7pdECw@mail.gmail.com>

On Sat, May 11, 2013 at 4:03 PM, Citizen Kant <citizenkant at gmail.com> wrote:

> Hi,
> this could be seen as an extravagant subject but that is not my original
> purpose. I still don't know if I want to become a programmer or not.


My guess is that you don't want to be a programmer.  Otherwise you would
know that you did.


> At this moment I'm just inspecting the environment. I'm making my way to
> Python (and OOP in general) from a philosophical perspective or point of
> view and try to set the more global definition of Python's core as an
> "entity". In order to do that, and following Wittgenstein's indication
> about that the true meaning of words doesn't reside on dictionaries but in
> the use that we make of them, the starting question I make to myself about
> Python is: which is the single and most basic use of Python as the entity
> it is? I mean, beside programming, what's the single and most basic result
> one can expect from "interacting" with it directly (interactive mode)? I
> roughly came to the idea that Python could be considered as an *economic
> mirror for data*, one that mainly *mirrors* the data the programmer types
> on its black surface, not exactly as the programmer originally typed it,
> but expressed in the most economic way possible. That's to say, for
> example, if one types >>>1+1 Python reflects >>>2. When data appears
> between apostrophes, then the mirror reflects, again, the same but
> expressed in the most economic way possible (that's to say without the
> apostrophes).
>
> So, would it be legal (true) to define Python's core as an entity that
> mirrors whatever data one presents to it (or feed it with) showing back the
> most shortened expression of that data?
>
> Don't get me wrong. I can see the big picture and the amazing things that
> programmers write on Python, it's just that my question points to the
> lowest level of it's existence.
>
> Thanks a lot for your time.
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>


-- 
Joel Goldstick
http://joelgoldstick.com
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From citizenkant at gmail.com  Sun May 12 10:17:02 2013
From: citizenkant at gmail.com (Citizen Kant)
Date: Sun, 12 May 2013 16:17:02 +0200
Subject: Python for philosophers
In-Reply-To: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
Message-ID: <CAMbF=C8qE1q_m5xKSFMt=gincCnOEZuext1Z2rch5AQQazC4yA@mail.gmail.com>

Thank you very much for your answers.

I'm afraid that, at this stage, I must prevent myself from "knowing too
much" about the subject. My idea here is trying to fill the gaps, mostly,
using intuition. What I do here is to try to "understand". That's different
from just knowing. Knowledge growth must be consequence of understanding's
increasing. As the scope of my understanding increases, the more I look for
increasing my knowledge. Never vice versa, because, knowing isn't like to
be right, it's just knowing.

Greg: your point is that
-------------------------------------
>>> 12**34
492223524295202670403711324312
2008064L

The input is 6 characters long, and the output
is 37 characters long. Is that more "economical"?
--------------------------------------------------------------------------

and that's a good one. But take in account that with "shortening" I refer
to "according to Python's axiomatic parameters". What's "shorten" if
expressed in Python? For example: I'm plainly aware that the word "python"
looks shorten than "01110000 01111001 01110100 01101000 01101111 01101110".
But it's shorten just for me and you and maybe for every single human, not
for the computer. You type "python", and the language (so to speak) thinks
"in my opinion you're not being economical enough coz with this you mean
01110000 01111001 01110100 01101000 01101111 01101110", and then mirrors
the supposedly result in its particular context. My "shorten" points to
what's shorten during and inside Python's runtime.

Maybe It'd be good if I explain myself a bit more. What I'm trying here is
to grasp Python from the game's abstraction point of view, as if it were,
for example, chess. That's why I need a real_player to point me to: (so to
speak, I wish I could express the ideas according to the python's syntax
but that's out of my scope by now)

games.python.board(like the chessboard but in abstract)  # with board I'm
not necessarily referring to the black on Python's command line or any
other substitutes for that, but to its axiomatic context. Which are those
unchangeable things that limit so firmly the dynamics of the game, and that
in this context must be considered like hardware, the most material part of
Python. Coz (in my neophyte opinion) these are the things that (in a more
or less obvious way) limit "the dynamic of any attempt to introduce a
change in this game".

games.python.pieces(a finite number of named elements)   # one example of
what in Python (unless for me) seems to look like pieces are
python.keywords(python2). Might be more entities that can be considered
like pieces...

games.python.start(the position that each piece must assume over the given
board in order to conform "the sign of this kind of game's starting
point")   # following the example of the only pieces I've recognized so
far, I would drive myself to think about the state of python.keywords
Of course with "state" I could be referring to any kind of state. The only
clue is that, as far I can see, is expected that those hypothetical states
come in pairs, like state(available, unavailable)

games.python.end(game's final point or highest achievement)  #I never
forget that checkmate is just a sign that can be observed looking at the
board or "axiomatic structure that in the game remains static". That
end_sign usually is, no more nor less than a transformation of the
start_sign, transformation that, sometimes, shorten it.

games.python.pieces.behavior(the legal or non erroneous modifications that
can be made to the start_sign in order to convert it to end_sign)

games.python.player.rear.avoid(what it must be avoided by any legal -non
erroneous- means)  # seems to be that the kind of things to be avoided are
not precisely making errors, since Python will tell. Making errors is just
something that's so illegal that simply doesn't take place. With "avoid" I
mean what happens when you get checked by running code that doesn't lead to
any error messages but at the same time doesn't give the expected result.

My goal right now is to produce one or more abstracts that explain (mainly
for myself but extensive to others) about how I deal with some problems
related to our "search for emphaty" nature at the time of what we tend to
consider "interaction" (learning to write in Python in interactive mode, or
just programming, is one of that cases). In essence, due to Python's lack
of empathy, one must adopt its shape and ways to (so to speak) "interact"
with it. Python could be considered like a solitary game, and in my opinion
could be taken as it is from the beginning, in order to properly understand
what one exactly is doing. That seems to be the best way to properly
"understand" Python; then knowledge will come, naturally as a perfect
search of, exactly, the things that "understanding" needs.

Any clue about this would be highly appreciated.


2013/5/11 Citizen Kant <citizenkant at gmail.com>

> Hi,
> this could be seen as an extravagant subject but that is not my original
> purpose. I still don't know if I want to become a programmer or not. At
> this moment I'm just inspecting the environment. I'm making my way to
> Python (and OOP in general) from a philosophical perspective or point of
> view and try to set the more global definition of Python's core as an
> "entity". In order to do that, and following Wittgenstein's indication
> about that the true meaning of words doesn't reside on dictionaries but in
> the use that we make of them, the starting question I make to myself about
> Python is: which is the single and most basic use of Python as the entity
> it is? I mean, beside programming, what's the single and most basic result
> one can expect from "interacting" with it directly (interactive mode)? I
> roughly came to the idea that Python could be considered as an *economic
> mirror for data*, one that mainly *mirrors* the data the programmer types
> on its black surface, not exactly as the programmer originally typed it,
> but expressed in the most economic way possible. That's to say, for
> example, if one types >>>1+1 Python reflects >>>2. When data appears
> between apostrophes, then the mirror reflects, again, the same but
> expressed in the most economic way possible (that's to say without the
> apostrophes).
>
> So, would it be legal (true) to define Python's core as an entity that
> mirrors whatever data one presents to it (or feed it with) showing back the
> most shortened expression of that data?
>
> Don't get me wrong. I can see the big picture and the amazing things that
> programmers write on Python, it's just that my question points to the
> lowest level of it's existence.
>
> Thanks a lot for your time.
>



-- 
------------------------------------------------------------------
?Has le?do ?Las Novelas Prohibidas? <http://lasnovelasprohibidas.com/>?
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From rosuav at gmail.com  Sun May 12 10:51:28 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 13 May 2013 00:51:28 +1000
Subject: Python for philosophers
In-Reply-To: <CAMbF=C8qE1q_m5xKSFMt=gincCnOEZuext1Z2rch5AQQazC4yA@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<CAMbF=C8qE1q_m5xKSFMt=gincCnOEZuext1Z2rch5AQQazC4yA@mail.gmail.com>
Message-ID: <CAPTjJmpjqYgz1xLRFyZP7E-7A+j+qDapyvGyfT5eDtFFWgayEg@mail.gmail.com>

On Mon, May 13, 2013 at 12:17 AM, Citizen Kant <citizenkant at gmail.com> wrote:
> Maybe It'd be good if I explain myself a bit more. What I'm trying here is
> to grasp Python from the game's abstraction point of view, as if it were,
> for example, chess.

Maybe you're going for something a little too complicated. Let's boil
the question down to a much MUCH simpler subset: expression
evaluation. And let's take Python itself right out of the picture, and
work with only the following elements:

* Parentheses ( )
* Multiplication and division * /
* Addition and subtraction + -
* Decimal integer constants 0123456789

This will give the basics of algebraic evaluation. It's quite fun to
build a simple little expression evaluator that just does these few
operations, and it's surprisingly useful (embed it within a command
interpreter, for instance). Some time ago I wrote one into a Windows
app (written in C++), and when I pulled it out just now and made it a
stand-alone tool, the whole thing was only ~60 lines of code. Nice and
easy to work with.

So, let's take an expression and see what it really means.

2*(3+4)+6

One way to interpret this is with a stack. Here's how Python evaluates
that expression:

>>> def foo():
	return 2*(three+4)+6

>>> dis.dis(foo)
  2           0 LOAD_CONST               1 (2)
              3 LOAD_GLOBAL              0 (three)
              6 LOAD_CONST               2 (4)
              9 BINARY_ADD
             10 BINARY_MULTIPLY
             11 LOAD_CONST               3 (6)
             14 BINARY_ADD
             15 RETURN_VALUE

(I had to replace one of the constants with a global, to foil the optimizer)

The LOAD statements add to an internal stack, the BINARY operations
pop two operands and push the result. This is more-or-less the same
technique as I used in my evaluator, except that instead of compiling
it to code, I just march straight through, left to right, and so I had
to maintain two stacks (one of operands, one of operators).

Is this what you had in mind when you wanted to grasp Python's
internals? Because it's pretty easy to explore, thanks to the dis
module. There's a huge amount that can be learned about the
interpreter, its optimizers, and so on, just by disassembling
functions. Alternatively, if you're thinking on a more abstract level,
leave Python aside altogether and pick up a book on language design.
Also can be awesome fun, but completely different.

ChrisA


From llanitedave at veawb.coop  Sun May 12 14:13:30 2013
From: llanitedave at veawb.coop (llanitedave)
Date: Sun, 12 May 2013 11:13:30 -0700 (PDT)
Subject: Python for philosophers
In-Reply-To: <mailman.1582.1368370291.3114.python-list@python.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<CAMbF=C8qE1q_m5xKSFMt=gincCnOEZuext1Z2rch5AQQazC4yA@mail.gmail.com>
	<mailman.1582.1368370291.3114.python-list@python.org>
Message-ID: <6e40860b-c0e5-46f9-9ba9-4ea4f4dc77c2@googlegroups.com>

On Sunday, May 12, 2013 7:51:28 AM UTC-7, Chris Angelico wrote:
> On Mon, May 13, 2013 at 12:17 AM, Citizen Kant <citizenkant at gmail.com> wrote:
> 
> > Maybe It'd be good if I explain myself a bit more. What I'm trying here is
> 
> > to grasp Python from the game's abstraction point of view, as if it were,
> 
> > for example, chess.
> 
> 
> 
> Maybe you're going for something a little too complicated. Let's boil
> 
> the question down to a much MUCH simpler subset: expression
> 
> evaluation. And let's take Python itself right out of the picture, and
> 
> work with only the following elements:
> 
> 
> 
> * Parentheses ( )
> 
> * Multiplication and division * /
> 
> * Addition and subtraction + -
> 
> * Decimal integer constants 0123456789
> 
> 
> 
> This will give the basics of algebraic evaluation. It's quite fun to
> 
> build a simple little expression evaluator that just does these few
> 
> operations, and it's surprisingly useful (embed it within a command
> 
> interpreter, for instance). Some time ago I wrote one into a Windows
> 
> app (written in C++), and when I pulled it out just now and made it a
> 
> stand-alone tool, the whole thing was only ~60 lines of code. Nice and
> 
> easy to work with.
> 
> 
> 
> So, let's take an expression and see what it really means.
> 
> 
> 
> 2*(3+4)+6
> 
> 
> 
> One way to interpret this is with a stack. Here's how Python evaluates
> 
> that expression:
> 
> 
> 
> >>> def foo():
> 
> 	return 2*(three+4)+6
> 
> 
> 
> >>> dis.dis(foo)
> 
>   2           0 LOAD_CONST               1 (2)
> 
>               3 LOAD_GLOBAL              0 (three)
> 
>               6 LOAD_CONST               2 (4)
> 
>               9 BINARY_ADD
> 
>              10 BINARY_MULTIPLY
> 
>              11 LOAD_CONST               3 (6)
> 
>              14 BINARY_ADD
> 
>              15 RETURN_VALUE
> 
> 
> 
> (I had to replace one of the constants with a global, to foil the optimizer)
> 
> 
> 
> The LOAD statements add to an internal stack, the BINARY operations
> 
> pop two operands and push the result. This is more-or-less the same
> 
> technique as I used in my evaluator, except that instead of compiling
> 
> it to code, I just march straight through, left to right, and so I had
> 
> to maintain two stacks (one of operands, one of operators).
> 
> 
> 
> Is this what you had in mind when you wanted to grasp Python's
> 
> internals? Because it's pretty easy to explore, thanks to the dis
> 
> module. There's a huge amount that can be learned about the
> 
> interpreter, its optimizers, and so on, just by disassembling
> 
> functions. Alternatively, if you're thinking on a more abstract level,
> 
> leave Python aside altogether and pick up a book on language design.
> 
> Also can be awesome fun, but completely different.
> 
> 
> 
> ChrisA

No, that won't help.  You're trying to give him knowledge; he wants understanding.


From rosuav at gmail.com  Sun May 12 17:48:28 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 13 May 2013 07:48:28 +1000
Subject: Python for philosophers
In-Reply-To: <6e40860b-c0e5-46f9-9ba9-4ea4f4dc77c2@googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<CAMbF=C8qE1q_m5xKSFMt=gincCnOEZuext1Z2rch5AQQazC4yA@mail.gmail.com>
	<mailman.1582.1368370291.3114.python-list@python.org>
	<6e40860b-c0e5-46f9-9ba9-4ea4f4dc77c2@googlegroups.com>
Message-ID: <CAPTjJmoyDoG4A+i9K4DChdsFWLWrxAFEd0tYqW_150xQh03MPQ@mail.gmail.com>

On Mon, May 13, 2013 at 4:13 AM, llanitedave <llanitedave at veawb.coop> wrote:
> On Sunday, May 12, 2013 7:51:28 AM UTC-7, Chris Angelico wrote:
>> On Mon, May 13, 2013 at 12:17 AM, Citizen Kant <citizenkant at gmail.com> wrote:
>>
>> > Maybe It'd be good if I explain myself a bit more. What I'm trying here is
>>
>> > to grasp Python from the game's abstraction point of view, as if it were,
>>
>> > for example, chess.
>>
>>
>>
>> Maybe you're going for something a little too complicated. Let's boil
>>
>> the question down to a much MUCH simpler subset: expression
>>
>> evaluation. And let's take Python itself right out of the picture, and
>>
>> work with only the following elements:
>>
>>
>>
>> * Parentheses ( )
>>
>> * Multiplication and division * /
>>
>> * Addition and subtraction + -
>>
>> * Decimal integer constants 0123456789
>>
>>
>>
>> This will give the basics of algebraic evaluation. It's quite fun to
>>
>> build a simple little expression evaluator that just does these few
>>
>> operations, and it's surprisingly useful (embed it within a command
>>
>> interpreter, for instance). Some time ago I wrote one into a Windows
>>
>> app (written in C++), and when I pulled it out just now and made it a
>>
>> stand-alone tool, the whole thing was only ~60 lines of code. Nice and
>>
>> easy to work with.
>>
>>
>>
>> So, let's take an expression and see what it really means.
>>
>>
>>
>> 2*(3+4)+6
>>
>>
>>
>> One way to interpret this is with a stack. Here's how Python evaluates
>>
>> that expression:
>>
>>
>>
>> >>> def foo():
>>
>>       return 2*(three+4)+6
>>
>>
>>
>> >>> dis.dis(foo)
>>
>>   2           0 LOAD_CONST               1 (2)
>>
>>               3 LOAD_GLOBAL              0 (three)
>>
>>               6 LOAD_CONST               2 (4)
>>
>>               9 BINARY_ADD
>>
>>              10 BINARY_MULTIPLY
>>
>>              11 LOAD_CONST               3 (6)
>>
>>              14 BINARY_ADD
>>
>>              15 RETURN_VALUE
>>
>>
>>
>> (I had to replace one of the constants with a global, to foil the optimizer)
>>
>>
>>
>> The LOAD statements add to an internal stack, the BINARY operations
>>
>> pop two operands and push the result. This is more-or-less the same
>>
>> technique as I used in my evaluator, except that instead of compiling
>>
>> it to code, I just march straight through, left to right, and so I had
>>
>> to maintain two stacks (one of operands, one of operators).
>>
>>
>>
>> Is this what you had in mind when you wanted to grasp Python's
>>
>> internals? Because it's pretty easy to explore, thanks to the dis
>>
>> module. There's a huge amount that can be learned about the
>>
>> interpreter, its optimizers, and so on, just by disassembling
>>
>> functions. Alternatively, if you're thinking on a more abstract level,
>>
>> leave Python aside altogether and pick up a book on language design.
>>
>> Also can be awesome fun, but completely different.
>>
>>
>>
>> ChrisA
>
> No, that won't help.  You're trying to give him knowledge; he wants understanding.

I can't give him understanding. Best I can do is offer facts, which
lead to knowledge, which lead to understanding if absorbed
appropriately. Also, sources of knowledge (like dis.dis) can be VERY
powerful tools in gaining understanding.

ChrisA


From steve+comp.lang.python at pearwood.info  Sun May 12 10:30:56 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 12 May 2013 14:30:56 GMT
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
Message-ID: <518fa7a0$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sun, 12 May 2013 16:17:02 +0200, Citizen Kant wrote:

> Any clue about this would be highly appreciated.

If you are interested in the intersection of programming and philosophy, 
I strongly recommend that you read "G?del, Escher, Bach: An Eternal 
Golden Braid" by Douglas R. Hofstadter.



-- 
Steven


From wuwei23 at gmail.com  Mon May 13 00:19:47 2013
From: wuwei23 at gmail.com (alex23)
Date: Sun, 12 May 2013 21:19:47 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<518fa7a0$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <aae7b596-c268-43ac-b8fb-c3dd2b440436@kq11g2000pbb.googlegroups.com>

On May 13, 12:30?am, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
> If you are interested in the intersection of programming and philosophy,
> I strongly recommend that you read "G?del, Escher, Bach: An Eternal
> Golden Braid" by Douglas R. Hofstadter.

+1



From rustompmody at gmail.com  Sun May 12 12:00:18 2013
From: rustompmody at gmail.com (rusi)
Date: Sun, 12 May 2013 09:00:18 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
Message-ID: <12751738-0de3-415b-8535-20d5d4e9ae1f@zo5g2000pbb.googlegroups.com>

On May 12, 7:17?pm, Citizen Kant <citizenk... at gmail.com> wrote:
> Maybe It'd be good if I explain myself a bit more. What I'm trying here is
> to grasp Python from the game's abstraction point of view, as if it were,
> for example, chess. That's why I need a real_player to point me to: (so to
> speak, I wish I could express the ideas according to the python's syntax
> but that's out of my scope by now)

On seeing the interest in games, I can only reiterate the suggestion
to look at rewrite systems
Here is on of the classics on rewrite systems

http://rewriting.loria.fr/documents/survey-draft.ps.gz

whose starting example is a game.


From greg.ewing at canterbury.ac.nz  Sun May 12 20:34:13 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Mon, 13 May 2013 12:34:13 +1200
Subject: Python for philosophers
In-Reply-To: <mailman.1581.1368368230.3114.python-list@python.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
Message-ID: <avaqo7Fsj3pU1@mid.individual.net>

Citizen Kant wrote:
> What I do here is to try to "understand". 
> That's different from just knowing. Knowledge growth must be consequence 
> of understanding's increasing. As the scope of my understanding 
> increases, the more I look for increasing my knowledge. Never vice 
> versa, because, knowing isn't like to be right, it's just knowing.

It doesn't always work that way. With some facts plus a
theory, you can deduce more facts. But it's always possible
for there to be more facts that you can't deduce from what
you already know.

> But take in account that with "shortening" I 
> refer to "according to Python's axiomatic parameters".

I think what you're trying to say is that it takes an
expression and reduces it to a canonical form, such as
a single number or single string.

That's true as far as it goes, but it barely scratches
the surface of what the Python interpreter is capable
of doing.

In the most general terms, the Python interpeter (or
any other computer system, for that matter) can be thought
of as something with an internal state, and a transition
function that takes the state together with some input
and produces another state together with some output:

    F(S1, I) --> (S2, O)

(Computer scientists call this a "finite state machine",
because there is a limited number of possible internal
states -- the computer only has so much RAM, disk space,
etc.)

This seems to be what you're trying to get at with your
game-of-chess analogy.

What distinguishes one computer system from another is
the transition function. The transition function of the
Python interpreter is rather complicated, and it's
unlikely that you would be able to figure out all its
details just by poking in inputs and observing the
outputs. If you really want to understand it, you're
going to have to learn some facts, I'm sorry to say. :-)

-- 
Greg


From steve+comp.lang.python at pearwood.info  Sun May 12 22:41:35 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 13 May 2013 02:41:35 GMT
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
Message-ID: <519052df$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Mon, 13 May 2013 12:34:13 +1200, Gregory Ewing wrote:

> In the most general terms, the Python interpeter (or any other computer
> system, for that matter) can be thought of as something with an internal
> state, and a transition function that takes the state together with some
> input and produces another state together with some output:
> 
>     F(S1, I) --> (S2, O)
> 
> (Computer scientists call this a "finite state machine", because there
> is a limited number of possible internal states -- the computer only has
> so much RAM, disk space, etc.)

That's not what finite state machine means. A finite state machine 
doesn't refer to the number of physical states of the underlying hardware 
implementing the device, it refers to the number of external states of 
the computation being performed. For example, a traffic light may be 
modelled by a Finite State Machine with three states: Red, Amber, Green. 
It may actually be implemented by a general purpose computer with 
trillions of internal states, or by a specialised electrical circuit, or 
by clockwork. The implementation doesn't matter. What matters is the 
three external states, any input to the device, plus the transition rules 
between them.

Python is not well-modelled as a Finite State Machine. Python is 
equivalent in computing power to a Turing Machine, while Finite State 
Machines are much weaker, so there are things that Python can do that a 
FSM cannot.


-- 
Steven


From rustompmody at gmail.com  Mon May 13 10:53:10 2013
From: rustompmody at gmail.com (rusi)
Date: Mon, 13 May 2013 07:53:10 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
	<519052df$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <5e2c6b41-e9af-4604-ad05-47fbea32ae15@zo5g2000pbb.googlegroups.com>

On May 13, 7:41?am, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
> Python is not well-modelled as a Finite State Machine. Python is
> equivalent in computing power to a Turing Machine, while Finite State
> Machines are much weaker, so there are things that Python can do that a
> FSM cannot.

Consider the following.

Python is turing-equivalent; so is C and scheme.
I now write a recursive factorial function in all 3.
[To level the pitch all three are written tail-recursively]

------------Python------------------
def fact(n,acc=1):
    return acc if not n else fact(n-1,n*acc)
------------C-------------------------
#include <stdio.h>
main(int argc, char **argv)
{
  printf("fact %d is %d\n", atoi(argv[1]), fact(atoi(argv[1],1)));
}

int fact(int n, int acc)
{
  return !n? acc : fact(n-1,acc*n);
}
---------------------------------
When I run these, the C happily keeps giving answers until a million

The python crashes around a thousand.

However examined closely we find that though the C is giving answers
its giving junk after around 12
fact 17 is -288522240
And 35 onwards its 0 (!!)

So finally we do it in scheme:
(define (fact n ac)
  (if (zero? n) ac (fact (1- n) (* ac n))))
--------------------------------------------------------

This program neither crashes (because of tail recursion) nor gives
wrong answers

However around 90000 my entire machine becomes completely unusable
with top showing guile (scheme) taking all the memory and kswapd next
in line.

So whats the moral?

The Turing model is essentially infinite.
[A TM to compute factorial would never crash because it can never be
built]

The machines we use are finite.
As a first approx we may say that languages like C,Python,Scheme are
Turing-complete.

However in fact when we have to stuff these (conceptually beautiful)
infinite objects into messy finite objects such as Intel hardware,
some corners have to be cut.

And these 3 -- C, Python, Scheme -- CUT THE CORNERS DIFFERENTLY

So when these corners dont matter -- Turing-equivalence is fine
When they do, we must make do living in a more messy finite world


From rosuav at gmail.com  Mon May 13 12:24:44 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 14 May 2013 02:24:44 +1000
Subject: Python for philosophers
In-Reply-To: <5e2c6b41-e9af-4604-ad05-47fbea32ae15@zo5g2000pbb.googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
	<519052df$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<5e2c6b41-e9af-4604-ad05-47fbea32ae15@zo5g2000pbb.googlegroups.com>
Message-ID: <CAPTjJmqQNxoMMwepHO2LiXC3A6jsimDwENbj93MA7bh0yMzABQ@mail.gmail.com>

On Tue, May 14, 2013 at 12:53 AM, rusi <rustompmody at gmail.com> wrote:
> int fact(int n, int acc)
> {
>   return !n? acc : fact(n-1,acc*n);
> }
> ---------------------------------
> When I run these, the C happily keeps giving answers until a million
>
> However examined closely we find that though the C is giving answers
> its giving junk after around 12
> fact 17 is -288522240
> And 35 onwards its 0 (!!)

That'll depend on your integer size. If it's a 32-bit integer, you
can't store numbers greater than 2**31-1 (if you declared it as
'unsigned int', you could go all the way to 2**32-1). I'm sure you
could write this to use the GNU Multi-Precision library, but it'd be a
lot more complicated. However, as far as I know, the Turing machine
never promises that; its cells aren't meant to be infinite integers.

The Python script is, of course, governed by sys.setrecursionlimit().
But by adding a simple driver, we can test the real limit:

import sys

def fact(n,acc=1):
    return acc if not n else fact(n-1,n*acc)

n=2
while True:
        sys.setrecursionlimit(n+2)
        print("fact",n,"has",len(str(fact(n))),"digits")
        n*=2

On my 64-bit system, running a recent trunk build of CPython 3.4, it
can calculate 8192! but not 16384! (segfault). The limit seems to be
12772; after that, boom. Your crash-point will quite probably vary,
and I'd say there'll be compile-time options that would change that.

Of course, after playing with this in Python, I had to try out Pike.
Using the exact same code you proposed for C, but with a different
main() to save me the hassle of keying in numbers manually, I get
this:

fact 8192 has 28504 digits - 0.026 secs
fact 16384 has 61937 digits - 0.097 secs
fact 32768 has 133734 digits - 0.389 secs
fact 65536 has 287194 digits - 1.628 secs
fact 131072 has 613842 digits - 7.114 secs
fact 262144 has 1306594 digits - 31.291 secs
fact 524288 has 2771010 digits - 133.146 secs

It's still going. One core consumed, happily working on 1048576!, and
not actually using all that much memory. Hmm.... looks like the Pike
optimizer has turned this non-recursive. Okay, let's tweak it so it's
not tail-recursion-optimizable:

  return n?n*fact(n-1,1):1;

Now it bombs at 65536, saying:

Svalue stack overflow. (99624 of 100000 entries on stack, needed 256
more entries)

Hey, it's better than a segfault, which is what C would have done :)
And it's a tweakable value, though I don't know what the consequences
are of increasing it (presumably increased RAM usage for all Pike
programs).

Your final conclusion is of course correct; nothing we build can be
truly infinite. But we can certainly give some very good
approximations, if we're prepared to pay for them. The reality is,
though, that we usually do not want to pay for approximations to
infinity; why is IEEE 754 floating point so much more used than, say,
arbitrary-precision rational? Most of the time, we'd rather have good
performance and adequate accuracy than abysmal performance and perfect
accuracy. But hey, if you want to render a Mandelbrot set and zoom in
to infinity, the option IS there.

ChrisA


From rustompmody at gmail.com  Mon May 13 14:14:16 2013
From: rustompmody at gmail.com (rusi)
Date: Mon, 13 May 2013 11:14:16 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
	<519052df$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<5e2c6b41-e9af-4604-ad05-47fbea32ae15@zo5g2000pbb.googlegroups.com>
	<mailman.1631.1368462293.3114.python-list@python.org>
Message-ID: <c1fac804-bf22-4786-b6d5-e699225d9530@a16g2000pbu.googlegroups.com>

On May 13, 9:24?pm, Chris Angelico <ros... at gmail.com> wrote:
>
> Your final conclusion is of course correct; nothing we build can be
> truly infinite. But we can certainly give some very good
> approximations, if we're prepared to pay for them. The reality is,
> though, that we usually do not want to pay for approximations to
> infinity; why is IEEE 754 floating point so much more used than, say,
> arbitrary-precision rational? Most of the time, we'd rather have good
> performance and adequate accuracy than abysmal performance and perfect
> accuracy. But hey, if you want to render a Mandelbrot set and zoom in
> to infinity, the option IS there.

Lets look at the costs of locomotion (which I am rounding to neat
figures for an easy discussion)

It costs $10K for a car which goes at around 80 kmph

Now if I want to move at 800 kmph I need to switch from car to plane
and that will cost me in millions

And if I want to move at 8000 kmph I need to be in a rocket in outer
space. Cost perhaps in billions

And maybe if I spend in trillions (leaving aside the question where I
got the trillions) maybe my rocket can go at 80,000 kmph

So what will it cost me to have a rocket that will go at 300,000 m/sec
(186,000 miles per second may be more familiar)?

So what am I driving at?

Some limitations are technological. Some are fundamental.

Earlier I talked of the fact that C, python and scheme hit the
finiteness wall in different ways/places.
machine word size is C's casualty
stack size is python's
memory is scheme's

The details are technological; the fact of finiteness is fundamental
just like the speed-of-light bar is fundamental.

The example of numbers is another such case.

The set of real numbers is in general not computable
Even if we restrict ourselves to the so-called computable real
numbers...
[interestingly Turing's original paper was on computable (real)
numbers]
we get into a soup because:
One can (somewhat simplistically) think of a real number as a
(potentially) infinite list of digits.
Now comparing two finite lists for equality is a trivial operation

However comparing two infinite lists gets us into trouble because both
lists may go on and on... and be same and same... for ever and ever...
In short equality for infinite lists (and therefore real numbers) is
undecidable.
[Well technically semidecidable because if they are different we get a
'not-equal' answer]

Sorry if this all sounds abstruse...
The other day I was reading someone saying that java -- which is after
all such an 'enterprisey' language -- had goofed by not providing a
half-decent money-type.

If you think about it, this is saying the opposite of your:
> But we can certainly give some very good  approximations, if we're prepared to pay for them.

He cannot use int and have a billionaire (or more correctly a
2147483648-aire) add a dollar and get to zero
Nor is it a great idea to use floating point and have some clever
programmer skim off the sub-penny round-off errors into his personal
account.

tl;dr
Computers are hopelessly finite
Much harder to deal with this finitude than to hand-wave the problem
away


From rosuav at gmail.com  Mon May 13 14:22:51 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 14 May 2013 04:22:51 +1000
Subject: Python for philosophers
In-Reply-To: <c1fac804-bf22-4786-b6d5-e699225d9530@a16g2000pbu.googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
	<519052df$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<5e2c6b41-e9af-4604-ad05-47fbea32ae15@zo5g2000pbb.googlegroups.com>
	<mailman.1631.1368462293.3114.python-list@python.org>
	<c1fac804-bf22-4786-b6d5-e699225d9530@a16g2000pbu.googlegroups.com>
Message-ID: <CAPTjJmobXt43JwSxSEjPGgWK2MXMQiD-3YLKK7Y6Tfgki+kG=w@mail.gmail.com>

On Tue, May 14, 2013 at 4:14 AM, rusi <rustompmody at gmail.com> wrote:
> It costs $10K for a car which goes at around 80 kmph
>
> Now if I want to move at 800 kmph I need to switch from car to plane
> and that will cost me in millions
>
> And if I want to move at 8000 kmph I need to be in a rocket in outer
> space. Cost perhaps in billions
>
> And maybe if I spend in trillions (leaving aside the question where I
> got the trillions) maybe my rocket can go at 80,000 kmph
>
> So what will it cost me to have a rocket that will go at 300,000 m/sec
> (186,000 miles per second may be more familiar)?

A $1 pocket flashlight.

:)

ChrisA


From dihedral88888 at googlemail.com  Sat May 18 19:56:41 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Sat, 18 May 2013 16:56:41 -0700 (PDT)
Subject: Python for philosophers
In-Reply-To: <mailman.1631.1368462293.3114.python-list@python.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
	<519052df$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<5e2c6b41-e9af-4604-ad05-47fbea32ae15@zo5g2000pbb.googlegroups.com>
	<mailman.1631.1368462293.3114.python-list@python.org>
Message-ID: <52b7a255-51f2-4b62-9c99-f8fcda5b7e97@googlegroups.com>

Chris Angelico? 2013?5?14????UTC+8??12?24?44????
> On Tue, May 14, 2013 at 12:53 AM, rusi <rustompmody at gmail.com> wrote:
> 
> > int fact(int n, int acc)
> 
> > {
> 
> >   return !n? acc : fact(n-1,acc*n);
> 
> > }
> 
> > ---------------------------------
> 
> > When I run these, the C happily keeps giving answers until a million
> 
> >
> 
> > However examined closely we find that though the C is giving answers
> 
> > its giving junk after around 12
> 
> > fact 17 is -288522240
> 
> > And 35 onwards its 0 (!!)
> 
> 
> 
> That'll depend on your integer size. If it's a 32-bit integer, you
> 
> can't store numbers greater than 2**31-1 (if you declared it as
> 
> 'unsigned int', you could go all the way to 2**32-1). I'm sure you
> 
> could write this to use the GNU Multi-Precision library, but it'd be a
> 
> lot more complicated. However, as far as I know, the Turing machine
> 
> never promises that; its cells aren't meant to be infinite integers.
> 
> 
> 
> The Python script is, of course, governed by sys.setrecursionlimit().
> 
> But by adding a simple driver, we can test the real limit:
> 
> 
> 
> import sys
> 
> 
> 
> def fact(n,acc=1):
> 
>     return acc if not n else fact(n-1,n*acc)
> 
> 
> 
> n=2
> 
> while True:
> 
>         sys.setrecursionlimit(n+2)
> 
>         print("fact",n,"has",len(str(fact(n))),"digits")
> 
>         n*=2
> 
> 
> 
> On my 64-bit system, running a recent trunk build of CPython 3.4, it
> 
> can calculate 8192! but not 16384! (segfault). The limit seems to be
> 
> 12772; after that, boom. Your crash-point will quite probably vary,
> 
> and I'd say there'll be compile-time options that would change that.
> 
> 
> 
> Of course, after playing with this in Python, I had to try out Pike.
> 
> Using the exact same code you proposed for C, but with a different
> 
> main() to save me the hassle of keying in numbers manually, I get
> 
> this:
> 
> 
> 
> fact 8192 has 28504 digits - 0.026 secs
> 
> fact 16384 has 61937 digits - 0.097 secs
> 
> fact 32768 has 133734 digits - 0.389 secs
> 
> fact 65536 has 287194 digits - 1.628 secs
> 
> fact 131072 has 613842 digits - 7.114 secs
> 
> fact 262144 has 1306594 digits - 31.291 secs
> 
> fact 524288 has 2771010 digits - 133.146 secs
> 
> 
> 
> It's still going. One core consumed, happily working on 1048576!, and
> 
> not actually using all that much memory. Hmm.... looks like the Pike
> 
> optimizer has turned this non-recursive. Okay, let's tweak it so it's
> 
> not tail-recursion-optimizable:
> 
> 
> 
>   return n?n*fact(n-1,1):1;
> 
> 
> 
> Now it bombs at 65536, saying:
> 
> 
> 
> Svalue stack overflow. (99624 of 100000 entries on stack, needed 256
> 
> more entries)
> 
> 
> 
> Hey, it's better than a segfault, which is what C would have done :)
> 
> And it's a tweakable value, though I don't know what the consequences
> 
> are of increasing it (presumably increased RAM usage for all Pike
> 
> programs).
> 
> 
> 
> Your final conclusion is of course correct; nothing we build can be
> 
> truly infinite. But we can certainly give some very good
> 
> approximations, if we're prepared to pay for them. The reality is,
> 
> though, that we usually do not want to pay for approximations to
> 
> infinity; why is IEEE 754 floating point so much more used than, say,
> 
> arbitrary-precision rational? Most of the time, we'd rather have good
> 
> performance and adequate accuracy than abysmal performance and perfect
> 
> accuracy. But hey, if you want to render a Mandelbrot set and zoom in
> 
> to infinity, the option IS there.
> 
> 
> 
> ChrisA

Hey, ChisA, are you delibrately to write a recursive version
to demonstrate the stack depth problem in Python?

def fact(n):
   ret=1
   if n>1: # integer checking is not used but can be added
      for x in xrange(n): ret*=x
   #print ret # debugging only for long integers 
   return ret 



In a 32 or 64 bit system, this non-recursive verssion
will be limited by the heap space not by the stack limit.


From rosuav at gmail.com  Sat May 18 20:04:45 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 19 May 2013 10:04:45 +1000
Subject: Python for philosophers
In-Reply-To: <52b7a255-51f2-4b62-9c99-f8fcda5b7e97@googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
	<519052df$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<5e2c6b41-e9af-4604-ad05-47fbea32ae15@zo5g2000pbb.googlegroups.com>
	<mailman.1631.1368462293.3114.python-list@python.org>
	<52b7a255-51f2-4b62-9c99-f8fcda5b7e97@googlegroups.com>
Message-ID: <CAPTjJmqHUf0DYDpNqmy17r6f4SEx5uedZ+79fH6Z6xdSCjjoEw@mail.gmail.com>

On Sun, May 19, 2013 at 9:56 AM, 88888 Dihedral
<dihedral88888 at googlemail.com> wrote:
> Hey, ChisA, are you delibrately to write a recursive version
> to demonstrate the stack depth problem in Python?
>
> def fact(n):
>    ret=1
>    if n>1: # integer checking is not used but can be added
>       for x in xrange(n): ret*=x
>    #print ret # debugging only for long integers
>    return ret
>
>
>
> In a 32 or 64 bit system, this non-recursive verssion
> will be limited by the heap space not by the stack limit.

And just when we're sure Dihedral's a bot, a post like this comes through.

Dihedral, are you intelligent? I'm still in two minds about this...
which may be why you so often appear to have no minds. I dunno.
Mathematics somewhere I fancy.

ChrisA


From dihedral88888 at googlemail.com  Sat May 18 22:30:43 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Sat, 18 May 2013 19:30:43 -0700 (PDT)
Subject: Python for philosophers
In-Reply-To: <mailman.1824.1368921893.3114.python-list@python.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
	<519052df$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<5e2c6b41-e9af-4604-ad05-47fbea32ae15@zo5g2000pbb.googlegroups.com>
	<mailman.1631.1368462293.3114.python-list@python.org>
	<52b7a255-51f2-4b62-9c99-f8fcda5b7e97@googlegroups.com>
	<mailman.1824.1368921893.3114.python-list@python.org>
Message-ID: <2751ccb7-a882-4ad6-ad14-386cb7ba4c65@googlegroups.com>

Chris Angelico? 2013?5?19????UTC+8??8?04?45????
> On Sun, May 19, 2013 at 9:56 AM, 88888 Dihedral
> 
> <dihedral88888 at googlemail.com> wrote:
> 
> > Hey, ChisA, are you delibrately to write a recursive version
> 
> > to demonstrate the stack depth problem in Python?
> 
> >
> 
> > def fact(n):
> 
> >    ret=1
> 
> >    if n>1: # integer checking is not used but can be added
> 
> >       for x in xrange(n): ret*=x
> 
> >    #print ret # debugging only for long integers
> 
> >    return ret
> 
> >
> 
> >
> 
> >
> 
> > In a 32 or 64 bit system, this non-recursive verssion
> 
> > will be limited by the heap space not by the stack limit.
> 
> 
> 
> And just when we're sure Dihedral's a bot, a post like this comes through.
> 
> 
> 
> Dihedral, are you intelligent? I'm still in two minds about this...
> 
> which may be why you so often appear to have no minds. I dunno.
> 
> Mathematics somewhere I fancy.
> 
> 
> 
> ChrisA

I am too lazy to write a factorial computations with primes
here.


From torriem at gmail.com  Sun May 19 00:46:22 2013
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 18 May 2013 22:46:22 -0600
Subject: Python for philosophers
In-Reply-To: <2751ccb7-a882-4ad6-ad14-386cb7ba4c65@googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
	<519052df$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<5e2c6b41-e9af-4604-ad05-47fbea32ae15@zo5g2000pbb.googlegroups.com>
	<mailman.1631.1368462293.3114.python-list@python.org>
	<52b7a255-51f2-4b62-9c99-f8fcda5b7e97@googlegroups.com>
	<mailman.1824.1368921893.3114.python-list@python.org>
	<2751ccb7-a882-4ad6-ad14-386cb7ba4c65@googlegroups.com>
Message-ID: <5198591E.60508@gmail.com>

On 05/18/2013 08:30 PM, 88888 Dihedral wrote:
> I am too lazy to write a factorial computations with primes
> here.

Ahh, that's better.


From js at globe.de  Thu May 16 10:13:49 2013
From: js at globe.de (Schneider)
Date: Thu, 16 May 2013 16:13:49 +0200
Subject: Python for philosophers
In-Reply-To: <avaqo7Fsj3pU1@mid.individual.net>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<avaqo7Fsj3pU1@mid.individual.net>
Message-ID: <5194E99D.4070805@globe.de>

Maybe the implementation of the Python Interpreter could be seen as 
transition function.
This can be understand in detail, but it even if you know how the 
interpreter works, you don't really know to work
_with_ the interpreter.
Even more, there are a lot of decisions, which are made 'by design' and 
don't have a clear answer. to see why somethings are
done in the way they are done you have to understand the philosophy of 
programming with python.

bg,
Johannes

On 13.05.2013 02:34, Gregory Ewing wrote:
> Citizen Kant wrote:
>> What I do here is to try to "understand". That's different from just 
>> knowing. Knowledge growth must be consequence of understanding's 
>> increasing. As the scope of my understanding increases, the more I 
>> look for increasing my knowledge. Never vice versa, because, knowing 
>> isn't like to be right, it's just knowing.
>
> It doesn't always work that way. With some facts plus a
> theory, you can deduce more facts. But it's always possible
> for there to be more facts that you can't deduce from what
> you already know.
>
>> But take in account that with "shortening" I refer to "according to 
>> Python's axiomatic parameters".
>
> I think what you're trying to say is that it takes an
> expression and reduces it to a canonical form, such as
> a single number or single string.
>
> That's true as far as it goes, but it barely scratches
> the surface of what the Python interpreter is capable
> of doing.
>
> In the most general terms, the Python interpeter (or
> any other computer system, for that matter) can be thought
> of as something with an internal state, and a transition
> function that takes the state together with some input
> and produces another state together with some output:
>
>    F(S1, I) --> (S2, O)
>
> (Computer scientists call this a "finite state machine",
> because there is a limited number of possible internal
> states -- the computer only has so much RAM, disk space,
> etc.)
>
> This seems to be what you're trying to get at with your
> game-of-chess analogy.
>
> What distinguishes one computer system from another is
> the transition function. The transition function of the
> Python interpreter is rather complicated, and it's
> unlikely that you would be able to figure out all its
> details just by poking in inputs and observing the
> outputs. If you really want to understand it, you're
> going to have to learn some facts, I'm sorry to say. :-)
>


-- 
GLOBE Development GmbH
K?nigsberger Strasse 260
48157 M?nsterGLOBE Development GmbH
K?nigsberger Strasse 260
48157 M?nster
0251/5205 390



From steve+comp.lang.python at pearwood.info  Sun May 12 23:25:30 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 13 May 2013 03:25:30 GMT
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
Message-ID: <51905d2a$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sun, 12 May 2013 16:17:02 +0200, Citizen Kant wrote:

> Thank you very much for your answers.
> 
> I'm afraid that, at this stage, I must prevent myself from "knowing too
> much" about the subject. My idea here is trying to fill the gaps,
> mostly, using intuition.

Then you are doomed to failure.

Intuition is greatly over-rated. Most of the time, it's just an excuse 
for prejudice, and a way to avoid understanding.


> What I do here is to try to "understand".
> That's different from just knowing. Knowledge growth must be consequence
> of understanding's increasing. As the scope of my understanding
> increases, the more I look for increasing my knowledge. Never vice
> versa, because, knowing isn't like to be right, it's just knowing.

Define your terms. What do you think "to know" means? What do you think 
"to understand" means?

[...]
> But take in account that with "shortening" I
> refer to "according to Python's axiomatic parameters". 

You cannot hypothesis about Python's behaviour in terms of its "axiomatic 
parameters" unless they know what those axiomatic parameters are. So what 
do you think Python's "axiomatic parameters" are, and how did you come to 
that conclusion given that you know virtually nothing about Python?


> What's "shorten"
> if expressed in Python? For example: I'm plainly aware that the word
> "python" looks shorten than "01110000 01111001 01110100 01101000
> 01101111 01101110". But it's shorten just for me and you and maybe for
> every single human, not for the computer. You type "python", and the
> language (so to speak) thinks "in my opinion you're not being economical
> enough coz with this you mean 01110000 01111001 01110100 01101000
> 01101111 01101110", 


Sheer nonsense, and I don't mean the part where you anthropomorphise 
Python. (The "intentional stance" is often an excellent way of reasoning 
about complex systems.)

Your premise that Python tries to be "economical" is incorrect. If 
anything, Python is the opposite: it is often profligate with resources 
(memory mostly) in order to save the human programmer time and effort. 
For example, Python dicts and lists may easily be four times as large as 
they could be (sometimes even bigger), *by design*. A list with 10 items 
may easily have space for 40 items. This is hardly economical, but it is 
a good trade-off in order to get better, and more predictable, 
performance.

[...]
> Maybe It'd be good if I explain myself a bit more. What I'm trying here
> is to grasp Python from the game's abstraction point of view, as if it
> were, for example, chess.

A lousy analogy. Python is nothing like chess. You might as well try to 
understand Python as if it were a toothbrush.



-- 
Steven


From invalid at invalid.invalid  Mon May 13 10:33:21 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Mon, 13 May 2013 14:33:21 +0000 (UTC)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<51905d2a$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <kmqtjh$hj4$1@reader1.panix.com>

On 2013-05-13, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> Your premise that Python tries to be "economical" is incorrect. If
> anything, Python is the opposite: it is often profligate with resources 
> (memory mostly) in order to save the human programmer time and effort.

IOW, Python is designed to be economical, but the resource of concern
is not computer memory, it's the programmer's time/effort.  Computer
memory gets cheaper every year.  My time gets more valuable every year
(hopefully).

-- 
Grant Edwards               grant.b.edwards        Yow! The entire CHINESE
                                  at               WOMEN'S VOLLEYBALL TEAM all
                              gmail.com            share ONE personality --
                                                   and have since BIRTH!!


From steve+comp.lang.python at pearwood.info  Mon May 13 03:13:23 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 13 May 2013 07:13:23 GMT
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
Message-ID: <51909292$0$29978$c3e8da3$5496439d@news.astraweb.com>

Some further details on something mentioned about Python being 
"economical".

On Sun, 12 May 2013 16:17:02 +0200, Citizen Kant wrote:

> For example: I'm plainly aware that the word "python" looks shorten than
> "01110000 01111001 01110100 01101000 01101111 01101110". But it's
> shorten just for me and you and maybe for every single human, not for
> the computer. You type "python", and the language (so to speak) thinks
> "in my opinion you're not being economical enough coz with this you mean
> 01110000 01111001 01110100 01101000 01101111 01101110", and then mirrors
> the supposedly result in its particular context. My "shorten" points to
> what's shorten during and inside Python's runtime.

In fact, the string "python" is implemented differently in different 
versions of Python. Picking Python 2.7, it may be implemented something 
like this binary string:

???????? ???????? ???????? ???????? ???????? ???????? ????????
???????? ???????? ???????? ???????? ???????? ???????? 00000000
01110000 00000000 01111001 00000000 01110100 00000000 01101000
00000000 01101111 00000000 01101110 00000000 00000000

where the spaces are purely for the convenience of the reader, and the 
question marks are internal values that I don't know enough to give the 
correct value. (Although I can predict that at least two sets of eight 
question marks is probably "00000000 00000110", the length of the string.)

To be precise, this is with a "narrow build", a "wide build" is even more 
profligate with memory. 

I'm not trying to beat the original Poster up for making an error, but 
demonstrating just how badly off track you can get by trying to reason 
from first principles (as Plato may have done) instead of empirical study 
(as Aristotle or Bacon may have done). Knowledge of how things actually 
are beats understanding of how they ought to be every time.


-- 
Steven


From wuwei23 at gmail.com  Mon May 13 05:05:05 2013
From: wuwei23 at gmail.com (alex23)
Date: Mon, 13 May 2013 02:05:05 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<51909292$0$29978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <3a6f27d8-275f-40eb-8aee-8f9083853b8e@yb1g2000pbc.googlegroups.com>

On May 13, 5:13?pm, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
> I'm not trying to beat the original Poster up for making an error, but
> demonstrating just how badly off track you can get by trying to reason
> from first principles (as Plato may have done) instead of empirical study
> (as Aristotle or Bacon may have done). Knowledge of how things actually
> are beats understanding of how they ought to be every time.

Nicely put, I may have to copy & paste this into another thread
here...

I always did have a soft spot for William James.


From neilc at norwich.edu  Mon May 13 09:52:56 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 13 May 2013 13:52:56 GMT
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1581.1368368230.3114.python-list@python.org>
	<51909292$0$29978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <avc9hoF65qtU1@mid.individual.net>

On 2013-05-13, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> I'm not trying to beat the original Poster up for making an
> error, but demonstrating just how badly off track you can get
> by trying to reason from first principles (as Plato may have
> done) instead of empirical study (as Aristotle or Bacon may
> have done). Knowledge of how things actually are beats
> understanding of how they ought to be every time.

Wasn't it Aristarchus who was considered a trouble-maker for
dropping different sized lead balls from a tower? They would land
simultaneously just as his teacher, who taught that heavier
objects fall faster, was walking past.

-- 
Neil Cerutti


From citizenkant at gmail.com  Mon May 13 19:32:43 2013
From: citizenkant at gmail.com (Citizen Kant)
Date: Tue, 14 May 2013 01:32:43 +0200
Subject: Python for philosophers
In-Reply-To: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
Message-ID: <CAMbF=C8n-F9Fbbs_qYUKH4azXYhnMb6QrbT+VUi_y6m8TE+ydw@mail.gmail.com>

I'm amazed with your feedback, even when due to a lack of knowledge I'm not
able to discuss some of them. I've been inspecting the stuff about
rewriting and that drew my attention to my first intuition of Python being
economic. Maybe could it support my impression about a thing thats behind
the language and got to do with condensing expressions until their end
point is reached. I'll absolutely read the book you recommended, coz looks
perfect. The dis module thing sounds and looks perfect too. Then again
something that was discussed here about Python being economic or not and
how or in which sense also threw some light on my first impression about
the language. Everything here is interesting and illustrative. Anyway, I
think that maybe I'm missing the point and I'm not being capable of
expressing the fundamentals of the reason why I'm here. I thought that the
most convenient thing to do is trying to keep myself attached to the
natural language I master (so to speak) and answer the a set of questions
that has been formulated. Maybe with this I'm helping myself.

Towards what purpose I'm just inspecting Python's environment?
Towards what purpose one would be just inspecting Chess' environment.
Eventually, I could end up playing; but that isn't told yet.

Do I want to learn to program?
I didn't say I've wanted to learn to program neither said the opposite.
I've said that I wasn't sure. And I said that because it's true. I'm not
sure. Sureness tends to proliferate at its highest rate when one is looking
to know. I'm looking to understand this something called Python. I've came
here as explorer. I know_about numbers of things that go_about a number of
topics of various supposedly most separated sciences. Since I sometimes
have the capacity for combining these knowledge units in a fancy way and
"realize" a great deal of things, is that I use a lot the verb "realize".
These constant instantiations of mine are like well done objects of real
true knowledge, made somehow by myself, by calling a method called
"understanding" from the class that corresponds and apply to any number of
memorized_data_objects that were previously instantiated in my mind coming
from my senses. For me this seems to look like what follows:

>>> understanding(combination(a_set_of _memorized_data_objects))

>>> def real_knowledge
>>>     understanding(a_set_of_memorized_data_objects)  # How does this
look?

I'm positive about that being told all the time about everything is pretty
much an economic issue, it just saves time, which in this environment saves
money, but at the cost of not playing with real knowledge that's verified
by each self (checksummed so to speak). Monkeys didn't developed our actual
brains just by being told about everything, but experiencing the phenomena,
that now we humans are talking about.

If not, then why do I care about Python programming?
In part is like a gut_decision. Internet is plenty of information about one
or another thing that one could be looking for, I've taken a look to Ruby
and Java and C++, but was a set of Python characteristics that really
matched with something inside of me. An entity named Python must be somehow
as a serpent. Don't forget that I'm with the freeing up of my memory, now
I'm not trying to follow the path of what's told but acting like the monkey
and pushing with my finger against the skin of the snake. Could be the case
that a stimulus_response method is being called inside of me. If that's the
case, objects instantiated by the stimulus_response method are the first
ones that can be considered scientific like, inside of me. Python also must
be an entity that's able to swallow, doesn't matter that it's chicken
object. Then it will throw whatever by its tail. For me that's interesting
and, in me, interestingness use to call the understanding method. Then I
realize that what's stated above implies that I can feed Python, and (here
starts the magic) see what type of whatever throws back by its tail. Then
I'll approach to smell any possible profit.

What do I aim to get out of this exercise?
Since actually I'm not running for programmer, my reason for understanding
Python must be sui generis and it is.

What do I think "Python's core" means?
More than thinking I'm just trying to guess what Python's core must be. Any
phenomena has a core. Maybe Python is economic as a snake and it is almost
all core. What would be the core of a digestive system covered with skin?
Considering Python as which in itself is all its truth and nothing but its
truth (that's to say thinking it without all its optionals) I tend to look
at it as if one of the most economic living creatures, and maybe a core in
itself.

One color note is that in the serpent class there's no attachment method.
Serpents are unemotional, they use to drop their eggs here and there
without a care. Serpent class lacks of empathy method.

What do I mean by "global definition"?
I mean one that would generic enough that includes myself.

What's an "entity"?
It could be any phenomena. I just wanted to frame something and draw the
attention to it, even if I'm still not in the position of label the
phenomena in a correct manner nor conceptualize it at all.

Why do my affirmation pre-suppose that exists something *more fundamental*
to programming that Python is for?
With this I don't mean more important but fundamental, that comes from
foundation, that's to say something meta or previous.

Aside from driving screws, what is the single and most basic use of a
screwdriver?
Aside the use that materialistic marketing tends to include in its eternal
propaganda, there's another use of whatever tool that I, the monkey, am
able to manipulate. My hand and my thought are engaged in the closest
relationship one can ever imagine. Manipulating, sets a foo in my brains,
foo that doesn't set the just listening to what someone would tell_about.
The case is I'm not able to get my material hands over Python, but that
doesn't mean that I must merely observe it as if it were non material. I'm
trying at least to emulate certain conditions to fill this gap. Modeling
something that could be called object_manipulation in order to understand
sounds crazy and maybe it is, it's paradoxical too, at the same time sounds
logic.


For my purposes, what is so special about interactive mode that I single it
out in this way?
Using the command line I'm setting myself closer to what I'm trying to
understand. That doesn't seem to be what one would consider doing wrong.

Why do I tend to believe that interactive mode isn't just like
non-interactive mode?
It seems that there are tiny differences between typing on the command line
and running a .py file. This drew my attention to the fact that being
economic has a lot to do with my purpose, so I decided to avoid the tiny
differences.

Why do I insist on the fact that "I must prevent myself from knowing too
much about a subject, that the best for me here is trying to fill the gaps,
mostly, using intuition?
This is an important question that I've tried to answer close to the start.

Why do I believe that intuition isn't greatly over-rated, and that most of
the time, isn't just an excuse for prejudice, and a way to avoid
understanding?
This is another good question that I've already tried to answer.

What do I think "to know" means? What do I think "to understand" means?
I've already tried to answer this.

What do I think Python's "axiomatic parameters" are, and how did I come to
that conclusion given that I know virtually nothing about Python?
I'm coping with this, as I've already stated, as if Python and Chess
inherit from Games. Games are known for being a particular kind of
phenomena, phenomena that not always but often includes something called
board, that's to say whatever in that game that remains immutable and
serves as its basic constant. With "axiomatic parameters" I've tried to
illustrate this immutable. That could be called perimeter or edge or
boundary, and even if all of those labels denote a limit, all of them,
unless for me, sound like... static. To think about Python in terms of
something that's static seems incorrect. "Axiomatic parameters" looked like
an initial limit that one can set, it just sounded accurate for a Python's
kind of thing.

Why do I maintain that Python could be something like chess.
>From the "trying to understand" point of view, everything can be considered
a game. In my opinion even science could be considered a game that could be
played in solitary mode.

 Am I getting closer to the point?


2013/5/11 Citizen Kant <citizenkant at gmail.com>

> Hi,
> this could be seen as an extravagant subject but that is not my original
> purpose. I still don't know if I want to become a programmer or not. At
> this moment I'm just inspecting the environment. I'm making my way to
> Python (and OOP in general) from a philosophical perspective or point of
> view and try to set the more global definition of Python's core as an
> "entity". In order to do that, and following Wittgenstein's indication
> about that the true meaning of words doesn't reside on dictionaries but in
> the use that we make of them, the starting question I make to myself about
> Python is: which is the single and most basic use of Python as the entity
> it is? I mean, beside programming, what's the single and most basic result
> one can expect from "interacting" with it directly (interactive mode)? I
> roughly came to the idea that Python could be considered as an *economic
> mirror for data*, one that mainly *mirrors* the data the programmer types
> on its black surface, not exactly as the programmer originally typed it,
> but expressed in the most economic way possible. That's to say, for
> example, if one types >>>1+1 Python reflects >>>2. When data appears
> between apostrophes, then the mirror reflects, again, the same but
> expressed in the most economic way possible (that's to say without the
> apostrophes).
>
> So, would it be legal (true) to define Python's core as an entity that
> mirrors whatever data one presents to it (or feed it with) showing back the
> most shortened expression of that data?
>
> Don't get me wrong. I can see the big picture and the amazing things that
> programmers write on Python, it's just that my question points to the
> lowest level of it's existence.
>
> Thanks a lot for your time.
>



-- 
------------------------------------------------------------------
?Has le?do ?Las Novelas Prohibidas? <http://lasnovelasprohibidas.com/>?
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From davea at davea.name  Mon May 13 21:47:48 2013
From: davea at davea.name (Dave Angel)
Date: Mon, 13 May 2013 21:47:48 -0400
Subject: Python for philosophers
In-Reply-To: <CAMbF=C8n-F9Fbbs_qYUKH4azXYhnMb6QrbT+VUi_y6m8TE+ydw@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<CAMbF=C8n-F9Fbbs_qYUKH4azXYhnMb6QrbT+VUi_y6m8TE+ydw@mail.gmail.com>
Message-ID: <519197C4.5090601@davea.name>

On 05/13/2013 07:32 PM, Citizen Kant wrote:
>
>    <SNIP>

>   Am I getting closer to the point?
>

Depends on whom you think you're talking to.  Clearly, you've replied to 
yourself, and top-posted besides.  That's not a conversation, it's a 
monologue.


-- 
DaveA


From jake.angulo at gmail.com  Tue May 14 02:31:00 2013
From: jake.angulo at gmail.com (Jake Angulo)
Date: Tue, 14 May 2013 16:31:00 +1000
Subject: Python for philosophers
In-Reply-To: <CAMbF=C8n-F9Fbbs_qYUKH4azXYhnMb6QrbT+VUi_y6m8TE+ydw@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<CAMbF=C8n-F9Fbbs_qYUKH4azXYhnMb6QrbT+VUi_y6m8TE+ydw@mail.gmail.com>
Message-ID: <CAH7RoS5NAfqSr_mRCo9CupTsvJOsiKiSjUp1m6fAiPeysFxOUQ@mail.gmail.com>

On Tue, May 14, 2013 at 9:32 AM, Citizen Kant <citizenkant at gmail.com> wrote:
> Do I want to learn to program?
> I didn't say I've wanted to learn to program neither said the
> opposite. I've said that I wasn't sure.


Hmmmm... i'd say you'll make very good business applications analyst.  In
fact i'd hazard to say you can make it to CIO.

Recommended reading:
* PERL for dummies by: Paul Hoffman
* Crime & Punishment by: Fyodor Dostoyevsky

With your natural philosophical talent, and just a little more
 supplementary knowledge you would Pwn & ruLZ!


Just...
pls...
dont do programming...
and Never do Python.


On Tue, May 14, 2013 at 9:32 AM, Citizen Kant <citizenkant at gmail.com> wrote:

> I'm amazed with your feedback, even when due to a lack of knowledge I'm
> not able to discuss some of them. I've been inspecting the stuff about
> rewriting and that drew my attention to my first intuition of Python being
> economic. Maybe could it support my impression about a thing thats behind
> the language and got to do with condensing expressions until their end
> point is reached. I'll absolutely read the book you recommended, coz looks
> perfect. The dis module thing sounds and looks perfect too. Then again
> something that was discussed here about Python being economic or not and
> how or in which sense also threw some light on my first impression about
> the language. Everything here is interesting and illustrative. Anyway, I
> think that maybe I'm missing the point and I'm not being capable of
> expressing the fundamentals of the reason why I'm here. I thought that the
> most convenient thing to do is trying to keep myself attached to the
> natural language I master (so to speak) and answer the a set of questions
> that has been formulated. Maybe with this I'm helping myself.
>
> Towards what purpose I'm just inspecting Python's environment?
> Towards what purpose one would be just inspecting Chess' environment.
> Eventually, I could end up playing; but that isn't told yet.
>
> Do I want to learn to program?
> I didn't say I've wanted to learn to program neither said the opposite.
> I've said that I wasn't sure. And I said that because it's true. I'm not
> sure. Sureness tends to proliferate at its highest rate when one is looking
> to know. I'm looking to understand this something called Python. I've came
> here as explorer. I know_about numbers of things that go_about a number of
> topics of various supposedly most separated sciences. Since I sometimes
> have the capacity for combining these knowledge units in a fancy way and
> "realize" a great deal of things, is that I use a lot the verb "realize".
> These constant instantiations of mine are like well done objects of real
> true knowledge, made somehow by myself, by calling a method called
> "understanding" from the class that corresponds and apply to any number of
> memorized_data_objects that were previously instantiated in my mind coming
> from my senses. For me this seems to look like what follows:
>
> >>> understanding(combination(a_set_of _memorized_data_objects))
>
> >>> def real_knowledge
> >>>     understanding(a_set_of_memorized_data_objects)  # How does this
> look?
>
> I'm positive about that being told all the time about everything is pretty
> much an economic issue, it just saves time, which in this environment saves
> money, but at the cost of not playing with real knowledge that's verified
> by each self (checksummed so to speak). Monkeys didn't developed our actual
> brains just by being told about everything, but experiencing the phenomena,
> that now we humans are talking about.
>
> If not, then why do I care about Python programming?
> In part is like a gut_decision. Internet is plenty of information about
> one or another thing that one could be looking for, I've taken a look to
> Ruby and Java and C++, but was a set of Python characteristics that really
> matched with something inside of me. An entity named Python must be somehow
> as a serpent. Don't forget that I'm with the freeing up of my memory, now
> I'm not trying to follow the path of what's told but acting like the monkey
> and pushing with my finger against the skin of the snake. Could be the case
> that a stimulus_response method is being called inside of me. If that's the
> case, objects instantiated by the stimulus_response method are the first
> ones that can be considered scientific like, inside of me. Python also must
> be an entity that's able to swallow, doesn't matter that it's chicken
> object. Then it will throw whatever by its tail. For me that's interesting
> and, in me, interestingness use to call the understanding method. Then I
> realize that what's stated above implies that I can feed Python, and (here
> starts the magic) see what type of whatever throws back by its tail. Then
> I'll approach to smell any possible profit.
>
> What do I aim to get out of this exercise?
> Since actually I'm not running for programmer, my reason for understanding
> Python must be sui generis and it is.
>
> What do I think "Python's core" means?
> More than thinking I'm just trying to guess what Python's core must be.
> Any phenomena has a core. Maybe Python is economic as a snake and it is
> almost all core. What would be the core of a digestive system covered with
> skin? Considering Python as which in itself is all its truth and nothing
> but its truth (that's to say thinking it without all its optionals) I tend
> to look at it as if one of the most economic living creatures, and maybe a
> core in itself.
>
> One color note is that in the serpent class there's no attachment method.
> Serpents are unemotional, they use to drop their eggs here and there
> without a care. Serpent class lacks of empathy method.
>
> What do I mean by "global definition"?
> I mean one that would generic enough that includes myself.
>
> What's an "entity"?
> It could be any phenomena. I just wanted to frame something and draw the
> attention to it, even if I'm still not in the position of label the
> phenomena in a correct manner nor conceptualize it at all.
>
> Why do my affirmation pre-suppose that exists something *more fundamental*
> to programming that Python is for?
> With this I don't mean more important but fundamental, that comes from
> foundation, that's to say something meta or previous.
>
> Aside from driving screws, what is the single and most basic use of a
> screwdriver?
> Aside the use that materialistic marketing tends to include in its eternal
> propaganda, there's another use of whatever tool that I, the monkey, am
> able to manipulate. My hand and my thought are engaged in the closest
> relationship one can ever imagine. Manipulating, sets a foo in my brains,
> foo that doesn't set the just listening to what someone would tell_about.
> The case is I'm not able to get my material hands over Python, but that
> doesn't mean that I must merely observe it as if it were non material. I'm
> trying at least to emulate certain conditions to fill this gap. Modeling
> something that could be called object_manipulation in order to understand
> sounds crazy and maybe it is, it's paradoxical too, at the same time sounds
> logic.
>
>
> For my purposes, what is so special about interactive mode that I single
> it out in this way?
> Using the command line I'm setting myself closer to what I'm trying to
> understand. That doesn't seem to be what one would consider doing wrong.
>
> Why do I tend to believe that interactive mode isn't just like
> non-interactive mode?
> It seems that there are tiny differences between typing on the command
> line and running a .py file. This drew my attention to the fact that being
> economic has a lot to do with my purpose, so I decided to avoid the tiny
> differences.
>
> Why do I insist on the fact that "I must prevent myself from knowing too
> much about a subject, that the best for me here is trying to fill the gaps,
> mostly, using intuition?
> This is an important question that I've tried to answer close to the start.
>
> Why do I believe that intuition isn't greatly over-rated, and that most of
> the time, isn't just an excuse for prejudice, and a way to avoid
> understanding?
> This is another good question that I've already tried to answer.
>
> What do I think "to know" means? What do I think "to understand" means?
> I've already tried to answer this.
>
> What do I think Python's "axiomatic parameters" are, and how did I come to
> that conclusion given that I know virtually nothing about Python?
> I'm coping with this, as I've already stated, as if Python and Chess
> inherit from Games. Games are known for being a particular kind of
> phenomena, phenomena that not always but often includes something called
> board, that's to say whatever in that game that remains immutable and
> serves as its basic constant. With "axiomatic parameters" I've tried to
> illustrate this immutable. That could be called perimeter or edge or
> boundary, and even if all of those labels denote a limit, all of them,
> unless for me, sound like... static. To think about Python in terms of
> something that's static seems incorrect. "Axiomatic parameters" looked like
> an initial limit that one can set, it just sounded accurate for a Python's
> kind of thing.
>
> Why do I maintain that Python could be something like chess.
> From the "trying to understand" point of view, everything can be
> considered a game. In my opinion even science could be considered a game
> that could be played in solitary mode.
>
>  Am I getting closer to the point?
>
>
> 2013/5/11 Citizen Kant <citizenkant at gmail.com>
>
>> Hi,
>> this could be seen as an extravagant subject but that is not my original
>> purpose. I still don't know if I want to become a programmer or not. At
>> this moment I'm just inspecting the environment. I'm making my way to
>> Python (and OOP in general) from a philosophical perspective or point of
>> view and try to set the more global definition of Python's core as an
>> "entity". In order to do that, and following Wittgenstein's indication
>> about that the true meaning of words doesn't reside on dictionaries but in
>> the use that we make of them, the starting question I make to myself about
>> Python is: which is the single and most basic use of Python as the entity
>> it is? I mean, beside programming, what's the single and most basic result
>> one can expect from "interacting" with it directly (interactive mode)? I
>> roughly came to the idea that Python could be considered as an *economic
>> mirror for data*, one that mainly *mirrors* the data the programmer
>> types on its black surface, not exactly as the programmer originally typed
>> it, but expressed in the most economic way possible. That's to say, for
>> example, if one types >>>1+1 Python reflects >>>2. When data appears
>> between apostrophes, then the mirror reflects, again, the same but
>> expressed in the most economic way possible (that's to say without the
>> apostrophes).
>>
>> So, would it be legal (true) to define Python's core as an entity that
>> mirrors whatever data one presents to it (or feed it with) showing back the
>> most shortened expression of that data?
>>
>> Don't get me wrong. I can see the big picture and the amazing things that
>> programmers write on Python, it's just that my question points to the
>> lowest level of it's existence.
>>
>> Thanks a lot for your time.
>>
>
>
>
> --
> ------------------------------------------------------------------
> ?Has le?do ?Las Novelas Prohibidas? <http://lasnovelasprohibidas.com/>?
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>
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From llanitedave at veawb.coop  Mon May 13 23:33:06 2013
From: llanitedave at veawb.coop (llanitedave)
Date: Mon, 13 May 2013 20:33:06 -0700 (PDT)
Subject: Python for philosophers
In-Reply-To: <mailman.1650.1368487966.3114.python-list@python.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
Message-ID: <b0942586-132a-4b9c-89df-6ff53d1426dc@googlegroups.com>

On Monday, May 13, 2013 4:32:43 PM UTC-7, Citizen Kant wrote:

>An entity named Python must be 
> somehow as a serpent. 


Moe like a dead parrot, actually.


From citizenkant at gmail.com  Tue May 14 05:11:34 2013
From: citizenkant at gmail.com (Citizen Kant)
Date: Tue, 14 May 2013 11:11:34 +0200
Subject: Fwd: Python for philosophers
In-Reply-To: <b0942586-132a-4b9c-89df-6ff53d1426dc@googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<b0942586-132a-4b9c-89df-6ff53d1426dc@googlegroups.com>
Message-ID: <CAMbF=C9O7wOUt+bY0R1m5yY1WUd=F-qJApy6j9Ag7KNGqee-qg@mail.gmail.com>

>>From: llanitedave <llanitedave at veawb.coop>


>>On Monday, May 13, 2013 4:32:43 PM UTC-7, Citizen Kant wrote:

>>>An entity named Python must be
>>> somehow as a serpent.


llanitedave wrote:

>>>> Moe like a dead parrot, actually.


That's a good one! Even If doesn't lead to the fact that Python (so to
speak) use to give an answer.
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From citizenkant at gmail.com  Tue May 14 06:36:14 2013
From: citizenkant at gmail.com (Citizen Kant)
Date: Tue, 14 May 2013 12:36:14 +0200
Subject: Fwd: Python for philosophers
In-Reply-To: <CAMbF=C9O7wOUt+bY0R1m5yY1WUd=F-qJApy6j9Ag7KNGqee-qg@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<b0942586-132a-4b9c-89df-6ff53d1426dc@googlegroups.com>
	<CAMbF=C9O7wOUt+bY0R1m5yY1WUd=F-qJApy6j9Ag7KNGqee-qg@mail.gmail.com>
Message-ID: <CAMbF=C_QyYbmfOT1b7hbystsVBWr7OYpyeWb90uhfvW+99QpCg@mail.gmail.com>

Case study (kind of)

Imagine that I use to explore with my mind a particular topic and I want to
map and model the mechanics of that exploration. That's mostly
metaphysical. I have a partner called Python with whom I must communicate
in Python. Which would be the basics that I must "know" in order to pass my
ideas to him properly. With this I mean using the units of my natural
language skills that match with his language, and using them in Python's
language context, in order to "program" at the highest level possible. It's
true that my program won't run yet but for me this is not an obstacle at
all, as when one writes a book one can start writing an index. For some
people, this index or highest level programming could look mostly like a
void thing coz lacks of the proper meat that a Python use to eat, and in a
sense they are right. But that's not the point. The point is that as soon
as I can I would start to dig deeper in that structure and build the proper
meat that my highest level labels are just naming. What if using my ability
to name what I actually think and recognize the path of whichever method I
call from my object of thinking, I'd like to start setting a context for
further immersion (inmersion with advanced mathematical notation an that?
Somebody commented about a couple of basic elements which I'm familiarized
with, like +, -, /, =, 1,2,3,4,5,6,7,8,9,0, (), etc. I know that Python has
a set of keywords, there's also a proper way in which one must express
wholes in Python, proper way which I'm not familiarized with but I'm able
to learn. Does this help?

For me, starting with Python is an affair of connecting with it. It's not
about including it in me or including me in it, but a kind of symbiotic
relationship. Unless for me, using my natural language as far as I can, but
constrained (formalized) by Python syntax in order to model using objects
and methods and classes that are still unable to run in Python (yet) seems
to be a good starting point for a symbiotic relationship. Understanding
might depend in our ability to set ourselves in the shoes of another.

Any clues? Since this is a real goal that I'm looking to accomplish, any
question that would clarify a bit more my states will be highly appreciated.
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From steve+comp.lang.python at pearwood.info  Tue May 14 01:29:45 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 14 May 2013 05:29:45 GMT
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
Message-ID: <5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>

On Tue, 14 May 2013 01:32:43 +0200, Citizen Kant wrote:

> An entity named Python must be somehow as a serpent. Don't forget that
> I'm with the freeing up of my memory, now I'm not trying to follow the
> path of what's told but acting like the monkey and pushing with my
> finger against the skin of the snake.

Python is not named after the snake, but after Monty Python the British 
comedy troupe. And they picked their name because it sounded funny.

http://en.wikipedia.org/wiki/Monty_Python




-- 
Steven


From citizenkant at gmail.com  Tue May 14 04:34:58 2013
From: citizenkant at gmail.com (Citizen Kant)
Date: Tue, 14 May 2013 10:34:58 +0200
Subject: Fwd: Python for philosophers
In-Reply-To: <5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAMbF=C_UjBy1POAdqWfUVVze4nJVP8MiT5EczQoZkLRZTCjPPA@mail.gmail.com>

2013/5/14 Steven D'Aprano <steve+comp.lang.python at pearwood.info>

> On Tue, 14 May 2013 01:32:43 +0200, Citizen Kant wrote:
>
> >> An entity named Python must be somehow as a serpent. Don't forget that
> >> I'm with the freeing up of my memory, now I'm not trying to follow the
> >> path of what's told but acting like the monkey and pushing with my
> >> finger against the skin of the snake.
>
> >Python is not named after the snake, but after Monty Python the British
> >comedy troupe. And they picked their name because it sounded funny.
>
> > http://en.wikipedia.org/wiki/Monty_Python<http://en.wikipedia.org/wiki/Monty_Python>
>
>
>
>
> I'm sorry to hear that. Mostly because, as an answer, seems to example
> very well the "taken because I've been told how things are" kind of
> actions, which is exactly the opposite of the point I'm trying to state.
>
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From tjreedy at udel.edu  Tue May 14 10:55:46 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Tue, 14 May 2013 10:55:46 -0400
Subject: Fwd: Python for philosophers
In-Reply-To: <CAMbF=C_UjBy1POAdqWfUVVze4nJVP8MiT5EczQoZkLRZTCjPPA@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAMbF=C_UjBy1POAdqWfUVVze4nJVP8MiT5EczQoZkLRZTCjPPA@mail.gmail.com>
Message-ID: <kmtj93$cec$1@ger.gmane.org>


> 2013/5/14 Steven D'Aprano <steve+comp.lang.python at pearwood.info
> <mailto:steve+comp.lang.python at pearwood.info>>

>      >Python is not named after the snake, but after Monty Python the
>     British
>      >comedy troupe. And they picked their name because it sounded funny.

That does not mean they were unaware that Pythons are snakes.
"requiring a "slippery-sounding" surname, they settled on "Python""

>      > http://en.wikipedia.org/wiki/Monty_Python
>     <http://en.wikipedia.org/wiki/Monty_Python>
>




From djc at news.invalid  Tue May 14 16:27:34 2013
From: djc at news.invalid (DJC)
Date: Tue, 14 May 2013 21:27:34 +0100
Subject: Fwd: Python for philosophers
In-Reply-To: <mailman.1664.1368520508.3114.python-list@python.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
Message-ID: <kmu6h4$8ai$1@dont-email.me>

On 14/05/13 09:34, Citizen Kant wrote:
> 2013/5/14 Steven D'Aprano <steve+comp.lang.python at pearwood.info>
>
>> On Tue, 14 May 2013 01:32:43 +0200, Citizen Kant wrote:
>>
>>>> An entity named Python must be somehow as a serpent. Don't forget that
>>>> I'm with the freeing up of my memory, now I'm not trying to follow the
>>>> path of what's told but acting like the monkey and pushing with my
>>>> finger against the skin of the snake.
>>
>>> Python is not named after the snake, but after Monty Python the British
>>> comedy troupe. And they picked their name because it sounded funny.
>>
>>> http://en.wikipedia.org/wiki/Monty_Python<http://en.wikipedia.org/wiki/Monty_Python>
>>
>>
>>
>>
>> I'm sorry to hear that. Mostly because, as an answer, seems to example
>> very well the "taken because I've been told how things are" kind of
>> actions, which is exactly the opposite of the point I'm trying to state.
>>
>
Emanual Kant was a real piss ant
	Who was very rarely stable


From invalid at invalid.invalid  Wed May 15 10:37:57 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 15 May 2013 14:37:57 +0000 (UTC)
Subject: Fwd: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
Message-ID: <kn06k5$jtu$2@reader1.panix.com>

On 2013-05-14, Citizen Kant <citizenkant at gmail.com> wrote:
> 2013/5/14 Steven D'Aprano <steve+comp.lang.python at pearwood.info>
>
>> On Tue, 14 May 2013 01:32:43 +0200, Citizen Kant wrote:
>>
>> >> An entity named Python must be somehow as a serpent. Don't forget that
>> >> I'm with the freeing up of my memory, now I'm not trying to follow the
>> >> path of what's told but acting like the monkey and pushing with my
>> >> finger against the skin of the snake.
>>
>> >Python is not named after the snake, but after Monty Python the British
>> >comedy troupe. And they picked their name because it sounded funny.
>>
>> > http://en.wikipedia.org/wiki/Monty_Python<http://en.wikipedia.org/wiki/Monty_Python>
>>
>> I'm sorry to hear that. Mostly because, as an answer, seems to example
>> very well the "taken because I've been told how things are" kind of
>> actions, which is exactly the opposite of the point I'm trying to state.

Firstly, watch your quoting, Steve D'Aprano didn't write that despite
your claim that he did.

Secondly, if a the person who named something tells you they named it
after A rather than B, what are you going to do other than "taken
because I've been told".  Are you claiming Guido lied about the source
of the name?

-- 
Grant Edwards               grant.b.edwards        Yow! My life is a patio
                                  at               of fun!
                              gmail.com            


From citizenkant at gmail.com  Wed May 15 15:55:17 2013
From: citizenkant at gmail.com (Citizen Kant)
Date: Wed, 15 May 2013 21:55:17 +0200
Subject: Fwd: Fwd: Python for philosophers
In-Reply-To: <kn06k5$jtu$2@reader1.panix.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
	<kn06k5$jtu$2@reader1.panix.com>
Message-ID: <CAMbF=C9KydSzqG=A3q0KU9EJ04hzu=Uh_UM-ko5eOf2-KB3UDg@mail.gmail.com>

On 2013-05-14, Citizen Kant <citizenkant at gmail.com> wrote:
> 2013/5/14 Steven D'Aprano <steve+comp.lang.python at pearwood.info>
>
>> On Tue, 14 May 2013 01:32:43 +0200, Citizen Kant wrote:
>>
>> >> An entity named Python must be somehow as a serpent. Don't forget that
>> >> I'm with the freeing up of my memory, now I'm not trying to follow the
>> >> path of what's told but acting like the monkey and pushing with my
>> >> finger against the skin of the snake.
>>
>> >Python is not named after the snake, but after Monty Python the British
>> >comedy troupe. And they picked their name because it sounded funny.
>>
>> > http://en.wikipedia.org/wiki/Monty_Python<
http://en.wikipedia.org/wiki/Monty_Python>
>>
>> I'm sorry to hear that. Mostly because, as an answer, seems to example
>> very well the "taken because I've been told how things are" kind of
>> actions, which is exactly the opposite of the point I'm trying to state.

Grant Edwards said:

>>>> Firstly, watch your quoting, Steve D'Aprano didn't write that despite
>>>> your claim that he did.

>>>> Secondly, if a the person who named something tells you they named it
>>>> after A rather than B, what are you going to do other than "taken
>>>> because I've been told".  Are you claiming Guido lied about the source
>>>> of the name?

Of course not. I'm just claiming that the tree (what's been told) is
preventing him from seeing the forest (what it is). If what's been told was
(put, by the very God of Uranus) that "the name's origin resides on a
string, that string's made up with the entire text of The Bible's Genesis
chapter with the word Python inserted not exactly in the middle but upper
on that tree", now I would be claiming the very same thing. As a matter of
class, the word python names first a python snake than a Monty Python,
which is 50% inspired by that python word, word that's been being
considered the given name of a particular kind of snake since times in
which Terry Gilliam wasn't even alive. Of course one always may want to
perform random hacking and turn tables just because and treat the word
python as a variable's name, setting that python equals Monty Python in
order to checkmate any given conversation. In that case we'll have to cope
then with the long lasting problem of being forced to name every python
snake as a Monty Python snake, due to the caprice of a programmer .
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From fabiosantosart at gmail.com  Wed May 15 20:12:57 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 16 May 2013 01:12:57 +0100
Subject: Fwd: Fwd: Python for philosophers
In-Reply-To: <CAMbF=C9KydSzqG=A3q0KU9EJ04hzu=Uh_UM-ko5eOf2-KB3UDg@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
	<kn06k5$jtu$2@reader1.panix.com>
	<CAMbF=C9KydSzqG=A3q0KU9EJ04hzu=Uh_UM-ko5eOf2-KB3UDg@mail.gmail.com>
Message-ID: <CAA=1kxR635=+BaC0B+CMZx1uAywWUZm=LBZqvbABhrsHh7tqMA@mail.gmail.com>

On 15 May 2013 20:59, "Citizen Kant" <citizenkant at gmail.com> wrote:
> Of course one always may want to perform random hacking and turn tables
just because and treat the word python as a variable's name, setting that
python equals Monty Python in order to checkmate any given conversation. In
that case we'll have to cope then with the long lasting problem of being
forced to name every python snake as a Monty Python snake, due to the
caprice of a programmer .
>

In Python all variables are actually labels. Labels refer to an object. An
object can be referred to by any amount of labels, but when no labels and
other references remain "pointed at" it, garbage collection destroys the
object. So if we set python equals Monty Python the actual python snake
will actually cease to exist.
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From wuwei23 at gmail.com  Wed May 15 19:55:47 2013
From: wuwei23 at gmail.com (alex23)
Date: Wed, 15 May 2013 16:55:47 -0700 (PDT)
Subject: Fwd: Fwd: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
	<kn06k5$jtu$2@reader1.panix.com>
	<mailman.1717.1368647727.3114.python-list@python.org>
Message-ID: <97a2c8b5-af49-4b05-aded-b326d17a211c@a15g2000pbu.googlegroups.com>

On May 16, 5:55?am, Citizen Kant <citizenk... at gmail.com> wrote:
> As a matter of
> class, the word python names first a python snake than a Monty Python,
> which is 50% inspired by that python word, word that's been being
> considered the given name of a particular kind of snake since times in
> which Terry Gilliam wasn't even alive.

"Namespaces are one honking great idea -- let's do more of those!" Or
to put it another way: context is important.

I find it both funny and sad that you think the name of the language
is preventing _others_ from seeing it as it is, when you're the only
one who seems to be fixated upon it.


From citizenkant at gmail.com  Thu May 16 08:28:11 2013
From: citizenkant at gmail.com (Citizen Kant)
Date: Thu, 16 May 2013 14:28:11 +0200
Subject: Fwd: Fwd: Fwd: Python for philosophers
In-Reply-To: <97a2c8b5-af49-4b05-aded-b326d17a211c@a15g2000pbu.googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
	<kn06k5$jtu$2@reader1.panix.com>
	<mailman.1717.1368647727.3114.python-list@python.org>
	<97a2c8b5-af49-4b05-aded-b326d17a211c@a15g2000pbu.googlegroups.com>
Message-ID: <CAMbF=C_0O4RhScLkdVQfZ1Nm7Yc4Uc26qxXgTT9f3APEkJti=A@mail.gmail.com>

On May 16, 5:55 am, Citizen Kant <citizenk... at gmail.com> wrote:
> As a matter of
> class, the word python names first a python snake than a Monty Python,
> which is 50% inspired by that python word, word that's been being
> considered the given name of a particular kind of snake since times in
> which Terry Gilliam wasn't even alive.


alex23 wrote:
>> "Namespaces are one honking great idea -- let's do more of those!" Or
>> to put it another way: context is important.

>> I find it both funny and sad that you think the name of the language
>> is preventing _others_ from seeing it as it is, when you're the only
>> one who seems to be fixated upon it.

Maybe would be good if I share with you guys some basics of scientific
humor. As alex23 well pointed out, there's a kind of funny and sad behind
this typical human reaction. There's a lot of science observing you as a
plain humans, science has been being observing you for a long time, and
science says that people tend to laugh_at when their intuition realizes
that is in front of whatever phenomena that could undermine its thought
foundations. Believe it or not, laughing_at is mostly a sign that one's
afraid of losing his reason, a manifest sign of psychological fear. For
example, being informed about that in a few hours an asteroid named X-21
will crash your planet destroying it would also first make you "react"
neglecting it, then react with the typical smile_at the messenger, then if
this given messenger insists you would normally tend to "overreact" and
laugh_at the previously mentioned messenger, and all this will happen even
if the information brought to you says the truth. Same happens if one's mom
come one day and tells that the guy one always believed is his father is in
fact not, that there's a real father of yours that will remain forever lost
in the crowd with whom she once had an occasional sex intercourse inside
the bathroom of a bar. Then first you'll smile_at her, then if she keeps on
insisting with the funny/sad subject that alex23 well pointed out you'll
eventually start overreacting and laugh_at her. At this point, only if she
keeps on insisting with her truth until you're tired enough of overreacting
because overreacting won't ever change the fact that the guy you (need to)
believe is your biological father could keep on being whatever you please
but not that, she can reach the goal of making you understand.

I'm just an honest and polite guy asking you guys a couple of simple out of
the box questions that are important for me. Everyone here has the freedom
to keep on with their own assumptions and beliefs. If someone's interested
on thinking outside the box with me for the sake of helping me, that would
be great and highly appreciated. Thinking outside the box isn't just a
cheap thing since it's highly creative. Take note that being able to think
and write in English doesn't make you writers as, put, Faulkner. Same
happens with any other language, same happens with Python.
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From rustompmody at gmail.com  Thu May 16 09:46:09 2013
From: rustompmody at gmail.com (rusi)
Date: Thu, 16 May 2013 06:46:09 -0700 (PDT)
Subject: Fwd: Fwd: Fwd: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
	<kn06k5$jtu$2@reader1.panix.com>
	<mailman.1717.1368647727.3114.python-list@python.org>
	<97a2c8b5-af49-4b05-aded-b326d17a211c@a15g2000pbu.googlegroups.com>
	<mailman.1751.1368707295.3114.python-list@python.org>
Message-ID: <ea81c424-0561-48bb-952a-3ccccdce94b1@oy9g2000pbb.googlegroups.com>

On May 16, 5:28?pm, Citizen Kant <citizenk... at gmail.com> wrote:
>
> I'm just an honest and polite guy asking you guys a couple of simple out of
> the box questions that are important for me. Everyone here has the freedom
> to keep on with their own assumptions and beliefs. If someone's interested
> on thinking outside the box with me for the sake of helping me, that would
> be great and highly appreciated. Thinking outside the box isn't just a
> cheap thing since it's highly creative. Take note that being able to think
> and write in English doesn't make you writers as, put, Faulkner. Same
> happens with any other language, same happens with Python.

Let me quote your first post (OP):


> I roughly came to the idea that Python could be considered as an *economic
> mirror for data*, one that mainly *mirrors* the data the programmer types
> on its black surface, not exactly as the programmer originally typed it,
> but expressed in the most economic way possible.

And let me suggest that you follow your own advise -- Can you say what
you have to say in 1/10th the number of words? Ok if not 1/10th then
1/5th? 1-third?

If you can, you are on the way to appreciating something which you
almost came to and then lost in interminable prolixity, to wit:
> The starting question I make to myself about Python is:
> which is the single and most basic use of Python as the entity it is?

IOW a programmer is one who quickly and easily comes to the nub/core/
kernel/essence of a problem and as easily and adroitly shaves off the
irrelevant.

Else: (you cant /wont reduce your prolixity)
    You are bullshitting us and we are being trolled by you


From rosuav at gmail.com  Thu May 16 10:00:12 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 17 May 2013 00:00:12 +1000
Subject: Fwd: Fwd: Fwd: Python for philosophers
In-Reply-To: <ea81c424-0561-48bb-952a-3ccccdce94b1@oy9g2000pbb.googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
	<kn06k5$jtu$2@reader1.panix.com>
	<mailman.1717.1368647727.3114.python-list@python.org>
	<97a2c8b5-af49-4b05-aded-b326d17a211c@a15g2000pbu.googlegroups.com>
	<mailman.1751.1368707295.3114.python-list@python.org>
	<ea81c424-0561-48bb-952a-3ccccdce94b1@oy9g2000pbb.googlegroups.com>
Message-ID: <CAPTjJmr960F-fVmYQ8Qw9eqFf3qT+2ed7VtcNNNn7vjEdKj5BA@mail.gmail.com>

On Thu, May 16, 2013 at 11:46 PM, rusi <rustompmody at gmail.com> wrote:
> IOW a programmer is one who quickly and easily comes to the nub/core/
> kernel/essence of a problem and as easily and adroitly shaves off the
> irrelevant.

+1.

This is a fairly good description of a programmer's job. Of course,
that's the theoretical and pure programmer... a professional
programmer often has to:

* Figure out what the problem *is* based on an incomplet description
from an incompetent user via a bored telephone operator

* Traverse a morass of bureaucratic requirements and politicking just
to get the necessary hardware/software to do his work

* Deal with the Layer Eight firewalling against the implementation of
the solution he comes up with

* Attend inane meetings with bikeshedding non-technical people who
have some kind of authority over the project

* Etcetera, etcetera, etcetera.

But yeah, that's what a programmer is. :)

ChrisA


From citizenkant at gmail.com  Thu May 16 16:06:34 2013
From: citizenkant at gmail.com (Citizen Kant)
Date: Thu, 16 May 2013 22:06:34 +0200
Subject: Fwd: Fwd: Fwd: Fwd: Python for philosophers
In-Reply-To: <ea81c424-0561-48bb-952a-3ccccdce94b1@oy9g2000pbb.googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
	<kn06k5$jtu$2@reader1.panix.com>
	<mailman.1717.1368647727.3114.python-list@python.org>
	<97a2c8b5-af49-4b05-aded-b326d17a211c@a15g2000pbu.googlegroups.com>
	<mailman.1751.1368707295.3114.python-list@python.org>
	<ea81c424-0561-48bb-952a-3ccccdce94b1@oy9g2000pbb.googlegroups.com>
Message-ID: <CAMbF=C-FjjBS8XX_WxYOkcFe4wC2bBxj4jQxZUp7SK_qyqeiRA@mail.gmail.com>

rusi said:

> And let me suggest that you follow your own advise -- Can you say what
> you have to say in 1/10th the number of words? Ok if not 1/10th then
> 1/5th? 1-third?

Thanks for the suggestion. I apologize for being that expansive; maybe you
are right about this. In my world less use to be less. I'll try to review
my doubts in order to express them in a much more concise format.

Of course this is not trolling at all, and I'm intrigued by how fast
someone can fall into that kind of conclusions...

I'm pretty much interested in the topic, so I'll review the stuff.
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From rustompmody at gmail.com  Sun May 19 13:46:07 2013
From: rustompmody at gmail.com (rusi)
Date: Sun, 19 May 2013 10:46:07 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
	<kn06k5$jtu$2@reader1.panix.com>
	<mailman.1717.1368647727.3114.python-list@python.org>
	<97a2c8b5-af49-4b05-aded-b326d17a211c@a15g2000pbu.googlegroups.com>
	<mailman.1751.1368707295.3114.python-list@python.org>
	<ea81c424-0561-48bb-952a-3ccccdce94b1@oy9g2000pbb.googlegroups.com>
	<mailman.1835.1368944986.3114.python-list@python.org>
Message-ID: <0c5a945a-2ec2-4e8a-bb2c-cc7fce9b3357@pd6g2000pbc.googlegroups.com>

On May 17, 1:06?am, Citizen Kant <citizenk... at gmail.com> wrote:
> rusi said:
>
> > And let me suggest that you follow your own advise -- Can you say what
> > you have to say in 1/10th the number of words? Ok if not 1/10th then
> > 1/5th? 1-third?
>
> Thanks for the suggestion. I apologize for being that expansive; maybe you
> are right about this. In my world less use to be less. I'll try to review
> my doubts in order to express them in a much more concise format.
>
> Of course this is not trolling at all, and I'm intrigued by how fast
> someone can fall into that kind of conclusions...
>
> I'm pretty much interested in the topic, so I'll review the stuff.

You are doing well -- Glad to see that.
Except for the subject line. What's with the Fwd-loop?
Anyway I have attempted to correct it


From llanitedave at veawb.coop  Fri May 17 01:42:01 2013
From: llanitedave at veawb.coop (llanitedave)
Date: Thu, 16 May 2013 22:42:01 -0700 (PDT)
Subject: Fwd: Fwd: Python for philosophers
In-Reply-To: <mailman.1751.1368707295.3114.python-list@python.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1650.1368487966.3114.python-list@python.org>
	<5191cbc9$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1664.1368520508.3114.python-list@python.org>
	<kn06k5$jtu$2@reader1.panix.com>
	<mailman.1717.1368647727.3114.python-list@python.org>
	<97a2c8b5-af49-4b05-aded-b326d17a211c@a15g2000pbu.googlegroups.com>
	<mailman.1751.1368707295.3114.python-list@python.org>
Message-ID: <855dcc14-20b8-4426-b1a7-2f1538b6c093@googlegroups.com>

On Thursday, May 16, 2013 5:28:11 AM UTC-7, Citizen Kant wrote:
> On May 16, 5:55?am, Citizen Kant <citizenk... at gmail.com> wrote:
> 
If someone's interested on thinking outside the box with me for the sake of helping me, that would be great and highly appreciated. 

Sorry, but you're asking for more than just thinking outside the box.  What you want would seem to require thinking from within the bottle.


From dreamingforward at gmail.com  Tue May 14 14:56:10 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Tue, 14 May 2013 11:56:10 -0700
Subject: Python for philosophers
In-Reply-To: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
Message-ID: <CAMjeLr8FjuRQxU-obOMTaT1uSRvVRCe7W_=4wG5ciqK8hM2J0A@mail.gmail.com>

On Sat, May 11, 2013 at 1:03 PM, Citizen Kant <citizenkant at gmail.com> wrote:
>I'm making my way to Python (and
> OOP in general) from a philosophical perspective or point of view and try to
> set the more global definition of Python's core as an "entity". In order to
> do that, and following Wittgenstein's indication about that the true meaning
> of words doesn't reside on dictionaries but in the use that we make of them,
> the starting question I make to myself about Python is: which is the single
> and most basic use of Python as the entity it is?

It is a way to form order from ideas, an *experimental* philosophy.
One can apply and implement a philosophy, taking it out of the realm
of ideas and simulate them in the machine.

> I mean, beside
> programming, what's the single and most basic result one can expect from
> "interacting" with it directly (interactive mode)?

A game of interactions.

> I roughly came to the
> idea that Python could be considered as an economic mirror for data, one
> that mainly mirrors the data the programmer types on its black surface,

That is called the "editor window" in our world that is displayed on
an electronic device called a computer display, but in Samael's world
it is a mirror into our world.  He misused it to rape the crown of the
Hebrew story (found in the Bible).

> So, would it be legal (true) to define Python's core as an entity that
> mirrors whatever data one presents to it (or feed it with) showing back the
> most shortened expression of that data?

No, that is me, Marcos.
-- 
MarkJ
Tacoma, Washington


From ned at nedbatchelder.com  Wed May 15 21:01:27 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Wed, 15 May 2013 21:01:27 -0400
Subject: Python for philosophers
In-Reply-To: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
Message-ID: <51942FE7.8080008@nedbatchelder.com>

On 5/11/2013 4:03 PM, Citizen Kant wrote:
> Don't get me wrong. I can see the big picture and the amazing things 
> that programmers write on Python, it's just that my question points to 
> the lowest level of it's existence.

Sometimes a cigar is just a cigar.  Python is a tool, it does what you 
tell it.  To make an analogy, or maybe to clarify your philosophical 
view of the world, consider a hammer.  What is the "lowest level of its 
existence"?

--Ned.


From tundra at tundraware.com  Wed May 15 21:17:07 2013
From: tundra at tundraware.com (Tim Daneliuk)
Date: Wed, 15 May 2013 20:17:07 -0500
Subject: Python for philosophers
In-Reply-To: <mailman.1728.1368666100.3114.python-list@python.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1728.1368666100.3114.python-list@python.org>
Message-ID: <vlod6a-2kr1.ln1@ozzie.tundraware.com>

On 05/15/2013 08:01 PM, Ned Batchelder wrote:
> On 5/11/2013 4:03 PM, Citizen Kant wrote:
>> Don't get me wrong. I can see the big picture and the amazing things that programmers write on Python, it's just that my question points to the lowest level of it's existence.
>
> Sometimes a cigar is just a cigar.  Python is a tool, it does what you tell it.  To make an analogy, or maybe to clarify your philosophical view of the world, consider a hammer.  What is the "lowest level of its existence"?
>
> --Ned.

All You People are making this way too hard.  To understand how
questions like the OPs ought be resolved, please read:

    http://pvspade.com/Sartre/cookbook.html




-- 
----------------------------------------------------------------------------
Tim Daneliuk     tundra at tundraware.com
PGP Key:         http://www.tundraware.com/PGP/



From tjreedy at udel.edu  Wed May 15 23:43:11 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Wed, 15 May 2013 23:43:11 -0400
Subject: Python for philosophers
In-Reply-To: <vlod6a-2kr1.ln1@ozzie.tundraware.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1728.1368666100.3114.python-list@python.org>
	<vlod6a-2kr1.ln1@ozzie.tundraware.com>
Message-ID: <kn1kk9$f2u$1@ger.gmane.org>

On 5/15/2013 9:17 PM, Tim Daneliuk wrote:

>     http://pvspade.com/Sartre/cookbook.html

Wikedly funny.




From bahamutzero8825 at gmail.com  Thu May 16 02:24:23 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Thu, 16 May 2013 01:24:23 -0500
Subject: Python for philosophers
In-Reply-To: <kn1kk9$f2u$1@ger.gmane.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1728.1368666100.3114.python-list@python.org>
	<vlod6a-2kr1.ln1@ozzie.tundraware.com> <kn1kk9$f2u$1@ger.gmane.org>
Message-ID: <51947B97.7090808@gmail.com>

Tim Daneliuk wrote:
> All You People are making this way too hard.  To understand how
> questions like the OPs ought be resolved, please read:
> 
>     http://pvspade.com/Sartre/cookbook.html

On this list, I would expect a Sartre reference to be something like this:
https://www.youtube.com/watch?v=crIJvcWkVcs

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From wuwei23 at gmail.com  Thu May 16 00:49:19 2013
From: wuwei23 at gmail.com (alex23)
Date: Wed, 15 May 2013 21:49:19 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1728.1368666100.3114.python-list@python.org>
	<vlod6a-2kr1.ln1@ozzie.tundraware.com>
Message-ID: <8f0d57d5-e68e-4de0-bb61-a5dbfa9edeea@ys5g2000pbc.googlegroups.com>

On May 16, 11:17?am, Tim Daneliuk <tun... at tundraware.com> wrote:
> ? ?http://pvspade.com/Sartre/cookbook.html

Best recipe for tuna casserole ever! Cheers for this :)



From tundra at tundraware.com  Thu May 16 00:55:37 2013
From: tundra at tundraware.com (Tim Daneliuk)
Date: Wed, 15 May 2013 23:55:37 -0500
Subject: Python for philosophers
In-Reply-To: <8f0d57d5-e68e-4de0-bb61-a5dbfa9edeea@ys5g2000pbc.googlegroups.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1728.1368666100.3114.python-list@python.org>
	<vlod6a-2kr1.ln1@ozzie.tundraware.com>
	<8f0d57d5-e68e-4de0-bb61-a5dbfa9edeea@ys5g2000pbc.googlegroups.com>
Message-ID: <519466C9.5070306@tundraware.com>

On 05/15/2013 11:49 PM, alex23 wrote:
> On May 16, 11:17 am, Tim Daneliuk <tun... at tundraware.com> wrote:
>>     http://pvspade.com/Sartre/cookbook.html
>
> Best recipe for tuna casserole ever! Cheers for this :)
>

"I have have realized that the traditional omelet form (eggs and cheese) is bourgeois."



-- 
----------------------------------------------------------------------------
Tim Daneliuk     tundra at tundraware.com
PGP Key:         http://www.tundraware.com/PGP/



From tundra at tundraware.com  Thu May 16 00:57:24 2013
From: tundra at tundraware.com (Tim Daneliuk)
Date: Wed, 15 May 2013 23:57:24 -0500
Subject: Python for philosophers
In-Reply-To: <mailman.1731.1368675801.3114.python-list@python.org>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1728.1368666100.3114.python-list@python.org>
	<vlod6a-2kr1.ln1@ozzie.tundraware.com>
	<mailman.1731.1368675801.3114.python-list@python.org>
Message-ID: <vi5e6a-2kr1.ln1@ozzie.tundraware.com>

On 05/15/2013 10:43 PM, Terry Jan Reedy wrote:
> On 5/15/2013 9:17 PM, Tim Daneliuk wrote:
>
>>     http://pvspade.com/Sartre/cookbook.html
>
> Wikedly funny.
>
>

"Today I made a Black Forest cake out of five pounds of cherries and a live beaver,"

-- 
----------------------------------------------------------------------------
Tim Daneliuk     tundra at tundraware.com
PGP Key:         http://www.tundraware.com/PGP/



From rustompmody at gmail.com  Thu May 16 01:08:31 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 15 May 2013 22:08:31 -0700 (PDT)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1728.1368666100.3114.python-list@python.org>
	<vlod6a-2kr1.ln1@ozzie.tundraware.com>
Message-ID: <b687c34a-e938-43f2-82c0-c4c20a3ce2cd@ul7g2000pbc.googlegroups.com>

On May 16, 6:17?am, Tim Daneliuk <tun... at tundraware.com> wrote:
> On 05/15/2013 08:01 PM, Ned Batchelder wrote:
>
> > On 5/11/2013 4:03 PM, Citizen Kant wrote:
> >> Don't get me wrong. I can see the big picture and the amazing things that programmers write on Python, it's just that my question points to the lowest level of it's existence.
>
> > Sometimes a cigar is just a cigar. ?Python is a tool, it does what you tell it. ?To make an analogy, or maybe to clarify your philosophical view of the world, consider a hammer. ?What is the "lowest level of its existence"?
>
> > --Ned.
>
> All You People are making this way too hard. ?To understand how
> questions like the OPs ought be resolved, please read:
>
> ? ?http://pvspade.com/Sartre/cookbook.html

Ha Ha! Very funny!
Also a serious reminder of what philosophy tends to become.
[Robert Pirsig wrote about the diff between philosophy and
philosophology]

>
> --
> ----------------------------------------------------------------------------
> Tim Daneliuk ? ? tun... at tundraware.com
> PGP Key: ? ? ? ?http://www.tundraware.com/PGP/



From invalid at invalid.invalid  Thu May 16 10:27:07 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Thu, 16 May 2013 14:27:07 +0000 (UTC)
Subject: Python for philosophers
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1728.1368666100.3114.python-list@python.org>
	<vlod6a-2kr1.ln1@ozzie.tundraware.com>
Message-ID: <kn2qbr$do4$1@reader1.panix.com>

On 2013-05-16, Tim Daneliuk <tundra at tundraware.com> wrote:
> On 05/15/2013 08:01 PM, Ned Batchelder wrote:
>> On 5/11/2013 4:03 PM, Citizen Kant wrote:
>>> Don't get me wrong. I can see the big picture and the amazing things that programmers write on Python, it's just that my question points to the lowest level of it's existence.
>>
>> Sometimes a cigar is just a cigar.  Python is a tool, it does what you tell it.  To make an analogy, or maybe to clarify your philosophical view of the world, consider a hammer.  What is the "lowest level of its existence"?
>>
>> --Ned.
>
> All You People are making this way too hard.  To understand how
> questions like the OPs ought be resolved, please read:
>
>     http://pvspade.com/Sartre/cookbook.html

Yea, I've decided we're being trolled...

-- 
Grant Edwards               grant.b.edwards        Yow! I'd like MY data-base
                                  at               JULIENNED and stir-fried!
                              gmail.com            


From tundra at tundraware.com  Thu May 16 13:50:44 2013
From: tundra at tundraware.com (Tim Daneliuk)
Date: Thu, 16 May 2013 12:50:44 -0500
Subject: Python for philosophers
In-Reply-To: <kn2qbr$do4$1@reader1.panix.com>
References: <CAMbF=C_GF_AKO2dD_=bH6VN2GVcSbC=KtHFLw62CKq2yitcfyQ@mail.gmail.com>
	<mailman.1728.1368666100.3114.python-list@python.org>
	<vlod6a-2kr1.ln1@ozzie.tundraware.com>
	<kn2qbr$do4$1@reader1.panix.com>
Message-ID: <ksif6a-r7v1.ln1@ozzie.tundraware.com>

On 05/16/2013 09:27 AM, Grant Edwards wrote:
> On 2013-05-16, Tim Daneliuk <tundra at tundraware.com> wrote:
>> On 05/15/2013 08:01 PM, Ned Batchelder wrote:
>>> On 5/11/2013 4:03 PM, Citizen Kant wrote:
>>>> Don't get me wrong. I can see the big picture and the amazing things that programmers write on Python, it's just that my question points to the lowest level of it's existence.
>>>
>>> Sometimes a cigar is just a cigar.  Python is a tool, it does what you tell it.  To make an analogy, or maybe to clarify your philosophical view of the world, consider a hammer.  What is the "lowest level of its existence"?
>>>
>>> --Ned.
>>
>> All You People are making this way too hard.  To understand how
>> questions like the OPs ought be resolved, please read:
>>
>>      http://pvspade.com/Sartre/cookbook.html
>
> Yea, I've decided we're being trolled...
>

   " I want to create an omelet that expresses the meaninglessness of existence,
     and instead they taste like cheese. "

-- 
----------------------------------------------------------------------------
Tim Daneliuk     tundra at tundraware.com
PGP Key:         http://www.tundraware.com/PGP/



From rosuav at gmail.com  Sun May 12 10:12:50 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 13 May 2013 00:12:50 +1000
Subject: Old version docs don't link to current version
Message-ID: <CAPTjJmoncBvwwJiv69RWnqah7-XG_GX215UT9jvJUKvYgcrgAA@mail.gmail.com>

Not sure if this is an oversight or something deliberate... could be either.

>From http://docs.python.org/3.0/library/http.server.html there's no
link to the current docs, even though from
http://docs.python.org/3/library/http.server.html it's possible to
switch to 3.2 and then back to 3.3 (or to 2.7, but that fails and
redirects since http.server doesn't exist in 2.7). This wouldn't be
much of a bother, except that a Google search for 'python http.server'
(which is the way I normally pull up Python docs) landed me on /3.0/
instead of /3/.

Was this intentional, along the lines of not touching the old and
unsupported docs?

ChrisA


From tjreedy at udel.edu  Sun May 12 15:32:58 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 12 May 2013 15:32:58 -0400
Subject: Old version docs don't link to current version
In-Reply-To: <CAPTjJmoncBvwwJiv69RWnqah7-XG_GX215UT9jvJUKvYgcrgAA@mail.gmail.com>
References: <CAPTjJmoncBvwwJiv69RWnqah7-XG_GX215UT9jvJUKvYgcrgAA@mail.gmail.com>
Message-ID: <kmoqot$6tt$1@ger.gmane.org>

On 5/12/2013 10:12 AM, Chris Angelico wrote:
> Not sure if this is an oversight or something deliberate... could be either.
>
>  From http://docs.python.org/3.0/library/http.server.html there's no
> link to the current docs, even though from
> http://docs.python.org/3/library/http.server.html it's possible to
> switch to 3.2 and then back to 3.3 (or to 2.7, but that fails and
> redirects since http.server doesn't exist in 2.7). This wouldn't be
> much of a bother, except that a Google search for 'python http.server'
> (which is the way I normally pull up Python docs) landed me on /3.0/
> instead of /3/.
>
> Was this intentional, along the lines of not touching the old and
> unsupported docs?

Cross referencing was added while 3.2 docs were still subject to 
revision. x.y docs are essentially frozen once the final x.y.z bugfix 
comes out.

Since I always enter the docs through docs.python.org/3/ (or /2/) typing 
just 'd' on Firefox history bar brings up both on the short history list 
to select. I then use module or general index.




From rosuav at gmail.com  Sun May 12 17:51:38 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 13 May 2013 07:51:38 +1000
Subject: Old version docs don't link to current version
In-Reply-To: <kmoqot$6tt$1@ger.gmane.org>
References: <CAPTjJmoncBvwwJiv69RWnqah7-XG_GX215UT9jvJUKvYgcrgAA@mail.gmail.com>
	<kmoqot$6tt$1@ger.gmane.org>
Message-ID: <CAPTjJmp2qyc45eYZ8e5bEbBV=km2MOJn+i6g+daQE2ZbW6d+pQ@mail.gmail.com>

On Mon, May 13, 2013 at 5:32 AM, Terry Jan Reedy <tjreedy at udel.edu> wrote:
> On 5/12/2013 10:12 AM, Chris Angelico wrote:
>>
>> Was this intentional, along the lines of not touching the old and
>> unsupported docs?
>
> Cross referencing was added while 3.2 docs were still subject to revision.
> x.y docs are essentially frozen once the final x.y.z bugfix comes out.

So, yeah, not touching the old docs. Okay!

It's not a particularly big deal, I can just delete a couple of
characters out of the URL. But it'd be nice if people who link to the
docs could start doing so using /3/ so that we have a chance of
getting past this eventually.

ChrisA


From ayjayn1101 at gmail.com  Sun May 12 15:33:44 2013
From: ayjayn1101 at gmail.com (Alex Norton)
Date: Sun, 12 May 2013 20:33:44 +0100
Subject: in need of some help regarding my rock paper scissors game
Message-ID: <CAAQ2WQxR7yuQp3Mn+zb0zsMLW53sWaPw2sPOyca=L1PRyO5r1Q@mail.gmail.com>

im new to python and im in the middle of making a RPS game for a college
unit.

i have used PyQt to create the GUI and i have received help regarding
adding the code to the buttons.

but its missing something as the error

'Traceback (most recent call last): File "C:\Users\Me\Desktop\testy.py",
line 174, in bWater.clicked.connect( water_clicked ) AttributeError: 'int'
object has no attribute 'clicked'' appears when i run the module.

i was wondering if somebody could walk me through making the game complete
and to add the results of the game (win/lose/stalemate) to the loutcome
label

 attached is the game file.
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From benjamin.kaplan at case.edu  Sun May 12 16:03:13 2013
From: benjamin.kaplan at case.edu (Benjamin Kaplan)
Date: Sun, 12 May 2013 13:03:13 -0700
Subject: in need of some help regarding my rock paper scissors game
In-Reply-To: <CAAQ2WQxR7yuQp3Mn+zb0zsMLW53sWaPw2sPOyca=L1PRyO5r1Q@mail.gmail.com>
References: <CAAQ2WQxR7yuQp3Mn+zb0zsMLW53sWaPw2sPOyca=L1PRyO5r1Q@mail.gmail.com>
Message-ID: <CAMuTYXiq6kLeRVvV40XTqsiU9HR1X1Ld3btmVdkTqmbbC6qc1A@mail.gmail.com>

On Sun, May 12, 2013 at 12:33 PM, Alex Norton <ayjayn1101 at gmail.com> wrote:
> im new to python and im in the middle of making a RPS game for a college
> unit.
>
> i have used PyQt to create the GUI and i have received help regarding adding
> the code to the buttons.
>
> but its missing something as the error
>
> 'Traceback (most recent call last): File "C:\Users\Me\Desktop\testy.py",
> line 174, in bWater.clicked.connect( water_clicked ) AttributeError: 'int'
> object has no attribute 'clicked'' appears when i run the module.
>
> i was wondering if somebody could walk me through making the game complete
> and to add the results of the game (win/lose/stalemate) to the loutcome
> label
>
>  attached is the game file.
>
> --

bWater is an int. Integers don't have a clicked attribute. So
bWater.clicked.connect(water_clicked) looks for the clicked attribute
of the integer bWater, can't find it, and throws an error. Also,
Python scripts are executed line by line- at the time you make that
call, the water_clicked function doesn't exist yet, so even if that
was the correct call, it wouldn't work here.

I haven't used PyQT before so I can't say what the correct way to set
this up would be, but that's at least what's causing this error.


From davea at davea.name  Sun May 12 19:04:48 2013
From: davea at davea.name (Dave Angel)
Date: Sun, 12 May 2013 19:04:48 -0400
Subject: in need of some help regarding my rock paper scissors game
In-Reply-To: <CAAQ2WQxR7yuQp3Mn+zb0zsMLW53sWaPw2sPOyca=L1PRyO5r1Q@mail.gmail.com>
References: <CAAQ2WQxR7yuQp3Mn+zb0zsMLW53sWaPw2sPOyca=L1PRyO5r1Q@mail.gmail.com>
Message-ID: <51902010.8020700@davea.name>

On 05/12/2013 03:33 PM, Alex Norton wrote:
> im new to python and im in the middle of making a RPS game for a college
> unit.
>
> i have used PyQt to create the GUI and i have received help regarding
> adding the code to the buttons.

I'm not at all familiar with PyQT, but I have used other GUIs, and I'm 
quite familiar with Python itself.

>
> but its missing something as the error
>
> 'Traceback (most recent call last): File "C:\Users\Me\Desktop\testy.py",
> line 174, in bWater.clicked.connect( water_clicked ) AttributeError: 'int'
> object has no attribute 'clicked'' appears when i run the module.

You've defined two very different bWater objects.  One is an instance 
attribute of the class Ui_MainWindow, while the other is an int at 
global scope.  The latter is never usefully referenced, but it's there 
to cause a confusing error message.  Those three calls through the 
clicked attrbute are evidently intended for the button object, which is 
inside the class instance.  My guess is that those three lines should be 
inside the setupUI method, and should have self. prefix on each.

Next problem is that there's a comment at the beginning:

# Form implementation generated from reading ui file 'mygui.ui'
#
# Created: Fri May 10 20:27:13 2013
#      by: PyQt4 UI code generator 4.10.1
#
# WARNING! All changes made in this file will be lost!

which implies this file is a generated one.  If you ever rerun that UI 
generator, you'll wipe out any changes you've made.  Again, I'm not 
familiar with PyQT, so I don't know how likely that is.

Next problem is that you have no top-level code that calls main(), which 
is evidently the code that gets things moving.  Generally, you want to 
put all the top-level code inside main(), in which case the call to 
main() would be the only top-level code left.  But there are exceptions. 
  imports should nearly always go to the top, at top level.  And you 
conditional functions need to stay at top-level just as you have them 
(the two clauses with try/cath in them).

Final problem that I can spot is that if you DO need to reference those 
four functions from mainline code, you'll have to move them earlier in 
the file.  But if you agreed with my earlier suggestion to move the 
three lines inside that method, then this wouldn't be a problem any more.

>
> i was wondering if somebody could walk me through making the game complete
> and to add the results of the game (win/lose/stalemate) to the loutcome
> label
>

Once you get to the innards of PyQT, I'll be no help at all.  But I hope 
I've given you a little push in the right direction.


-- 
DaveA


From denismfmcmahon at gmail.com  Mon May 13 16:36:07 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Mon, 13 May 2013 20:36:07 +0000 (UTC)
Subject: in need of some help regarding my rock paper scissors game
References: <mailman.1592.1368387232.3114.python-list@python.org>
Message-ID: <kmrirn$mqd$6@dont-email.me>

On Sun, 12 May 2013 20:33:44 +0100, Alex Norton wrote:

> 'Traceback (most recent call last): File "C:\Users\Me\Desktop\testy.py",
> line 174, in bWater.clicked.connect( water_clicked ) AttributeError:
> 'int'
> object has no attribute 'clicked'' appears when i run the module.

It looks to me as if bWater is an integer value and doesn't have 
a .clicked attribute.

Where is bWater assigned, and what is it assigned to?

If you have a clickable "water" widget of some sort in your gui, what is 
the click handler for that widget defined as?

-- 
Denis McMahon, denismfmcmahon at gmail.com


From titanix88 at gmail.com  Sun May 12 19:23:16 2013
From: titanix88 at gmail.com (Mr. Joe)
Date: Mon, 13 May 2013 05:23:16 +0600
Subject: Differences of "!=" operator behavior in python3 and python2 [ bug? ]
Message-ID: <CAJxoosfPri76e+Zp802a3Ve5d9aY5Mrav0VLwU64bxJt1bZDag@mail.gmail.com>

I seem to stumble upon a situation where "!=" operator misbehaves in
python2.x. Not sure if it's my misunderstanding or a bug in python
implementation. Here's a demo code to reproduce the behavior -
"""
# -*- coding: utf-8 -*-
from __future__ import unicode_literals, print_function

class DemoClass(object):
    def __init__(self, val):
        self.val = val

    def __eq__(self, other):
        return self.val == other.val

x = DemoClass('a')
y = DemoClass('a')

print("x == y: {0}".format(x == y))
print("x != y: {0}".format(x != y))
print("not x == y: {0}".format(not x == y))
"""

In python3, the output is as expected:
"""
x == y: True
x != y: False
not x == y: False
"""

In python2.7.3, the output is:
"""
x == y: True
x != y: True
not x == y: False
"""
Which is not correct!!

Thanks in advance for clarifications.
Regards,
TB


From ned at nedbatchelder.com  Sun May 12 19:35:39 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Sun, 12 May 2013 19:35:39 -0400
Subject: Differences of "!=" operator behavior in python3 and python2
	[ bug? ]
In-Reply-To: <CAJxoosfPri76e+Zp802a3Ve5d9aY5Mrav0VLwU64bxJt1bZDag@mail.gmail.com>
References: <CAJxoosfPri76e+Zp802a3Ve5d9aY5Mrav0VLwU64bxJt1bZDag@mail.gmail.com>
Message-ID: <5190274B.5090308@nedbatchelder.com>

On 5/12/2013 7:23 PM, Mr. Joe wrote:
> I seem to stumble upon a situation where "!=" operator misbehaves in
> python2.x. Not sure if it's my misunderstanding or a bug in python
> implementation. Here's a demo code to reproduce the behavior -
> """
> # -*- coding: utf-8 -*-
> from __future__ import unicode_literals, print_function
>
> class DemoClass(object):
>      def __init__(self, val):
>          self.val = val
>
>      def __eq__(self, other):
>          return self.val == other.val
>
> x = DemoClass('a')
> y = DemoClass('a')
>
> print("x == y: {0}".format(x == y))
> print("x != y: {0}".format(x != y))
> print("not x == y: {0}".format(not x == y))
> """
>
> In python3, the output is as expected:
> """
> x == y: True
> x != y: False
> not x == y: False
> """

In Python 3, if __ne__ isn't defined, "!=" will call __eq__ and negate 
the result.
> In python2.7.3, the output is:
> """
> x == y: True
> x != y: True
> not x == y: False
> """
> Which is not correct!!

In Python 2, "!=" only calls __ne__.  Since you don't have one defined, 
it's using the built-in object comparison, and since x and y are 
different objects, they are not equal to each other, so x != y is True.

> Thanks in advance for clarifications.
> Regards,
> TB



From christian at python.org  Sun May 12 19:39:03 2013
From: christian at python.org (Christian Heimes)
Date: Mon, 13 May 2013 01:39:03 +0200
Subject: Differences of "!=" operator behavior in python3 and python2
	[ bug? ]
In-Reply-To: <CAJxoosfPri76e+Zp802a3Ve5d9aY5Mrav0VLwU64bxJt1bZDag@mail.gmail.com>
References: <CAJxoosfPri76e+Zp802a3Ve5d9aY5Mrav0VLwU64bxJt1bZDag@mail.gmail.com>
Message-ID: <kmp96i$3er$1@ger.gmane.org>

Am 13.05.2013 01:23, schrieb Mr. Joe:
> I seem to stumble upon a situation where "!=" operator misbehaves in
> python2.x. Not sure if it's my misunderstanding or a bug in python
> implementation. Here's a demo code to reproduce the behavior -
> """

Python 2.7 doesn't use the negation of __eq__ when your class doesn't
provide a __ne__ function. Just add a print() to your __eq__ method and
you'll notice the different.

You have to provide both:


class DemoClass(object):
    def __init__(self, val):
        self.val = val

    def __eq__(self, other):
        if not isinstance(other, DemoClass):
            return NotImplemented
        return self.val == other.val

    def __ne__(self, other):
        if not isinstance(other, DemoClass):
            return NotImplemented
        return self.val != other.val

or

    def __ne__(self, other):
        result = self.__eq__(other)
        if result is NotImplemented:
             return NotImplemented
        return not result





From ian.g.kelly at gmail.com  Sun May 12 19:40:17 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sun, 12 May 2013 17:40:17 -0600
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
In-Reply-To: <CAJxoosfPri76e+Zp802a3Ve5d9aY5Mrav0VLwU64bxJt1bZDag@mail.gmail.com>
References: <CAJxoosfPri76e+Zp802a3Ve5d9aY5Mrav0VLwU64bxJt1bZDag@mail.gmail.com>
Message-ID: <CALwzidmxpEO7v0PnsKbGd6RsVF4Gv3Q4nc5u7JVrYb1QkiED2g@mail.gmail.com>

On Sun, May 12, 2013 at 5:23 PM, Mr. Joe <titanix88 at gmail.com> wrote:
> I seem to stumble upon a situation where "!=" operator misbehaves in
> python2.x. Not sure if it's my misunderstanding or a bug in python
> implementation. Here's a demo code to reproduce the behavior -

The != operator is implemented by the __ne__ special method.  In
Python 3, the default implementation of __ne__ is to call __eq__ and
return the opposite of whatever it returns.  In Python 2, __ne__ calls
the older __cmp__ method instead, which is no longer meaningful in
Python 3.


From sg552 at hotmail.co.uk  Sun May 12 19:52:18 2013
From: sg552 at hotmail.co.uk (Rotwang)
Date: Mon, 13 May 2013 00:52:18 +0100
Subject: Differences of "!=" operator behavior in python3 and python2
	[ bug? ]
In-Reply-To: <mailman.1606.1368402067.3114.python-list@python.org>
References: <CAJxoosfPri76e+Zp802a3Ve5d9aY5Mrav0VLwU64bxJt1bZDag@mail.gmail.com>
	<mailman.1606.1368402067.3114.python-list@python.org>
Message-ID: <kmp9oi$6g1$1@dont-email.me>

On 13/05/2013 00:40, Ian Kelly wrote:
> On Sun, May 12, 2013 at 5:23 PM, Mr. Joe <titanix88 at gmail.com> wrote:
>> I seem to stumble upon a situation where "!=" operator misbehaves in
>> python2.x. Not sure if it's my misunderstanding or a bug in python
>> implementation. Here's a demo code to reproduce the behavior -
>
> The != operator is implemented by the __ne__ special method.  In
> Python 3, the default implementation of __ne__ is to call __eq__ and
> return the opposite of whatever it returns.

One should be aware, however, that this doesn't necessarily apply to 
classes inheriting from builtins other than object (a fact that recently 
bit me on the a***):

 >>> class spam:
	def __eq__(self, other):
		print('spam')
		return super().__eq__(other)

	
 >>> class eggs(list):
	def __eq__(self, other):
		print('eggs')
		return super().__eq__(other)

	
 >>> spam() != spam()
spam
spam
True
 >>> eggs() != eggs()
False


From alister.ware at ntlworld.com  Mon May 13 05:59:03 2013
From: alister.ware at ntlworld.com (Alister)
Date: Mon, 13 May 2013 09:59:03 GMT
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
References: <mailman.1603.1368401007.3114.python-list@python.org>
Message-ID: <HP2kt.66723$Tl3.12499@fx29.fr7>

On Mon, 13 May 2013 05:23:16 +0600, Mr. Joe wrote:

> I seem to stumble upon a situation where "!=" operator misbehaves in
> python2.x. Not sure if it's my misunderstanding or a bug in python
> implementation. Here's a demo code to reproduce the behavior -
> """
> # -*- coding: utf-8 -*-
> from __future__ import unicode_literals, print_function
> 
> class DemoClass(object):
>     def __init__(self, val):
>         self.val = val
> 
>     def __eq__(self, other):
>         return self.val == other.val
> 
> x = DemoClass('a')
> y = DemoClass('a')
> 
> print("x == y: {0}".format(x == y))
> print("x != y: {0}".format(x != y))
> print("not x == y: {0}".format(not x == y))
> """
> 
> In python3, the output is as expected:
> """
> x == y: True x != y: False not x == y: False """
> 
> In python2.7.3, the output is:
> """
> x == y: True x != y: True not x == y: False """
> Which is not correct!!
> 
> Thanks in advance for clarifications.
> Regards,
> TB

this looks to me like an issue with operator precidence

you code is evaluating as (Not x) == y
rather than not (x == y)

why the difference between 2.7 & 3.X is beyond my knowledge of the 
language

The other explanations seem to detail things at low level but it is all 
Greek to me 


-- 
Nice guys finish last.
		-- Leo Durocher


From fabiosantosart at gmail.com  Mon May 13 13:26:50 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 13 May 2013 18:26:50 +0100
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
In-Reply-To: <HP2kt.66723$Tl3.12499@fx29.fr7>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
Message-ID: <CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>

On 13 May 2013 11:04, "Alister" <alister.ware at ntlworld.com> wrote:
> this looks to me like an issue with operator precidence
>
> you code is evaluating as (Not x) == y
> rather than not (x == y)

I can say for sure that the precedence is as expected. I always use "not
... == ..." Instead of !=.
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From ned at nedbatchelder.com  Mon May 13 14:08:39 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Mon, 13 May 2013 14:08:39 -0400
Subject: Differences of "!=" operator behavior in python3 and python2
	[ bug? ]
In-Reply-To: <CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
Message-ID: <51912C27.3020809@nedbatchelder.com>


On 5/13/2013 1:26 PM, F?bio Santos wrote:
>
>
> On 13 May 2013 11:04, "Alister" <alister.ware at ntlworld.com 
> <mailto:alister.ware at ntlworld.com>> wrote:
> > this looks to me like an issue with operator precidence
> >
> > you code is evaluating as (Not x) == y
> > rather than not (x == y)
>
> I can say for sure that the precedence is as expected. I always use 
> "not ... == ..." Instead of !=.
>
>

If you don't mind my asking, why do you do that?

--Ned.

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From rosuav at gmail.com  Mon May 13 14:15:22 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 14 May 2013 04:15:22 +1000
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
In-Reply-To: <51912C27.3020809@nedbatchelder.com>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
Message-ID: <CAPTjJmoo2rzMS0j0TmkXMrfd=kHPC6nn-ssvOJLZZrfA6=mwMg@mail.gmail.com>

On Tue, May 14, 2013 at 4:08 AM, Ned Batchelder <ned at nedbatchelder.com> wrote:
>
> On 5/13/2013 1:26 PM, F?bio Santos wrote:
>
>
> On 13 May 2013 11:04, "Alister" <alister.ware at ntlworld.com> wrote:
>> this looks to me like an issue with operator precidence
>>
>> you code is evaluating as (Not x) == y
>> rather than not (x == y)
>
> I can say for sure that the precedence is as expected. I always use "not ...
> == ..." Instead of !=.
>
>
>
> If you don't mind my asking, why do you do that?

I think it's fairly obvious. Like the stumpy-tailed dog from "The
Loaded Dog" [1], he's saving up the != operator in case he needs it
later.

ChrisA

[1] Full text here. http://jendi.bowmeow.com.au/loadeddog1.html


From fabiosantosart at gmail.com  Mon May 13 14:28:29 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 13 May 2013 19:28:29 +0100
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
In-Reply-To: <51912C27.3020809@nedbatchelder.com>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
Message-ID: <CAA=1kxS=5s2dYZ_h-gAXxVRGu+dpvSPmavz63pUviU+2qyy5_A@mail.gmail.com>

I think it is more readable. When doing more complicated statements I use
!= instead, but when it's a single test I prefer not ? ==

It's a personal thing. It may also have to do with the fact that I didn't
know python had != when I was a novice.
On 13 May 2013 19:08, "Ned Batchelder" <ned at nedbatchelder.com> wrote:

>
> On 5/13/2013 1:26 PM, F?bio Santos wrote:
>
>
> On 13 May 2013 11:04, "Alister" <alister.ware at ntlworld.com> wrote:
> > this looks to me like an issue with operator precidence
> >
> > you code is evaluating as (Not x) == y
> > rather than not (x == y)
>
> I can say for sure that the precedence is as expected. I always use "not
> ... == ..." Instead of !=.
>
>
> If you don't mind my asking, why do you do that?
>
> --Ned.
>
>
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From alister.ware at ntlworld.com  Mon May 13 17:17:41 2013
From: alister.ware at ntlworld.com (Alister)
Date: Mon, 13 May 2013 21:17:41 GMT
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
Message-ID: <VLckt.68242$kO.37986@fx14.fr7>

On Mon, 13 May 2013 19:28:29 +0100, F?bio Santos wrote:

> I think it is more readable. When doing more complicated statements I
> use != instead, but when it's a single test I prefer not ? ==
> 
> It's a personal thing. It may also have to do with the fact that I
> didn't know python had != when I was a novice.
> On 13 May 2013 19:08, "Ned Batchelder" <ned at nedbatchelder.com> wrote:
> 

I would then still write it as not (x == y) to make it clear to myself & 
avoid any possible confusion although I think that X != Y is much 
cleaner. 
2 lines from the zen stand out here:-

Explicit is better than implicit.
in the face of ambiguity refuse the temptation to guess.

there are many features of Python (& other languages) i did not now when 
I started but have adopted once I understood what they were & how they 
worked. then again use what you are most comfortable with.

Practicality beats purity



From fabiosantosart at gmail.com  Mon May 13 17:48:28 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 13 May 2013 22:48:28 +0100
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
In-Reply-To: <VLckt.68242$kO.37986@fx14.fr7>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7>
Message-ID: <CAA=1kxQ6k4K3ZG+ODbbm=R4DhvoAYfMjYpzGnLGpfuCjHnD-_g@mail.gmail.com>

On Mon, May 13, 2013 at 10:17 PM, Alister <alister.ware at ntlworld.com> wrote:
> On Mon, 13 May 2013 19:28:29 +0100, F?bio Santos wrote:
>
>> I think it is more readable. When doing more complicated statements I
>> use != instead, but when it's a single test I prefer not ? ==
>>
>> It's a personal thing. It may also have to do with the fact that I
>> didn't know python had != when I was a novice.
>> On 13 May 2013 19:08, "Ned Batchelder" <ned at nedbatchelder.com> wrote:
>>
>
> I would then still write it as not (x == y) to make it clear to myself &
> avoid any possible confusion although I think that X != Y is much
> cleaner.
> 2 lines from the zen stand out here:-
>
> Explicit is better than implicit.
> in the face of ambiguity refuse the temptation to guess.
>

And here I was, thinking I was being pythonic. I hope other people
using my code will be able to understand it well, not just myself, so
using the most common idioms should be the best way to go.


--
F?bio Santos


From breamoreboy at yahoo.co.uk  Mon May 13 18:53:01 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 13 May 2013 23:53:01 +0100
Subject: Differences of "!=" operator behavior in python3 and python2
	[ bug? ]
In-Reply-To: <VLckt.68242$kO.37986@fx14.fr7>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7>
Message-ID: <kmrqsa$uf3$1@ger.gmane.org>

On 13/05/2013 22:17, Alister wrote:
> On Mon, 13 May 2013 19:28:29 +0100, F?bio Santos wrote:
>
>> I think it is more readable. When doing more complicated statements I
>> use != instead, but when it's a single test I prefer not ? ==
>>
>> It's a personal thing. It may also have to do with the fact that I
>> didn't know python had != when I was a novice.
>> On 13 May 2013 19:08, "Ned Batchelder" <ned at nedbatchelder.com> wrote:
>>
>
> I would then still write it as not (x == y) to make it clear to myself &
> avoid any possible confusion although I think that X != Y is much
> cleaner.
> 2 lines from the zen stand out here:-
>
> Explicit is better than implicit.
> in the face of ambiguity refuse the temptation to guess.
>
> there are many features of Python (& other languages) i did not now when
> I started but have adopted once I understood what they were & how they
> worked. then again use what you are most comfortable with.
>
> Practicality beats purity
>

I much prefer the alternative <> for != but some silly people insisted 
that this be removed from Python3.  Just how stupid can you get?

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From davea at davea.name  Mon May 13 19:22:24 2013
From: davea at davea.name (Dave Angel)
Date: Mon, 13 May 2013 19:22:24 -0400
Subject: Differences of "!=" operator behavior in python3 and python2
	[ bug? ]
In-Reply-To: <kmrqsa$uf3$1@ger.gmane.org>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7> <kmrqsa$uf3$1@ger.gmane.org>
Message-ID: <519175B0.90603@davea.name>

On 05/13/2013 06:53 PM, Mark Lawrence wrote:
> On 13/05/2013 22:17, Alister wrote:
>> On Mon, 13 May 2013 19:28:29 +0100, F?bio Santos wrote:
>>
>>> I think it is more readable. When doing more complicated statements I
>>> use != instead, but when it's a single test I prefer not ? ==
>>>
>>> It's a personal thing. It may also have to do with the fact that I
>>> didn't know python had != when I was a novice.
>>> On 13 May 2013 19:08, "Ned Batchelder" <ned at nedbatchelder.com> wrote:
>>>
>>
>> I would then still write it as not (x == y) to make it clear to myself &
>> avoid any possible confusion although I think that X != Y is much
>> cleaner.
>> 2 lines from the zen stand out here:-
>>
>> Explicit is better than implicit.
>> in the face of ambiguity refuse the temptation to guess.
>>
>> there are many features of Python (& other languages) i did not now when
>> I started but have adopted once I understood what they were & how they
>> worked. then again use what you are most comfortable with.
>>
>> Practicality beats purity
>>
>
> I much prefer the alternative <> for != but some silly people insisted
> that this be removed from Python3.  Just how stupid can you get?
>

So which special methods should the <> operator call?  By rights it 
ought to call both __gt__ and __lt__ and return True if either of them 
is True.


-- 
DaveA


From cs at zip.com.au  Mon May 13 19:30:40 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Tue, 14 May 2013 09:30:40 +1000
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
In-Reply-To: <519175B0.90603@davea.name>
References: <519175B0.90603@davea.name>
Message-ID: <20130513233040.GA97066@cskk.homeip.net>

On 13May2013 19:22, Dave Angel <davea at davea.name> wrote:
| On 05/13/2013 06:53 PM, Mark Lawrence wrote:
| >I much prefer the alternative <> for != but some silly people insisted
| >that this be removed from Python3.  Just how stupid can you get?
| 
| So which special methods should the <> operator call?  By rights it
| ought to call both __gt__ and __lt__ and return True if either of
| them is True.

Surely it should require both of them to be true...

Personally I'm for != given we have ==. Aside from notational
consistency it makes conceptual sense for unordered types, which
<> does not really.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>


From davea at davea.name  Mon May 13 21:41:33 2013
From: davea at davea.name (Dave Angel)
Date: Mon, 13 May 2013 21:41:33 -0400
Subject: Differences of "!=" operator behavior in python3 and python2
	[ bug? ]
In-Reply-To: <20130513233040.GA97066@cskk.homeip.net>
References: <519175B0.90603@davea.name>
	<20130513233040.GA97066@cskk.homeip.net>
Message-ID: <5191964D.9040900@davea.name>

On 05/13/2013 07:30 PM, Cameron Simpson wrote:
> On 13May2013 19:22, Dave Angel <davea at davea.name> wrote:
> | On 05/13/2013 06:53 PM, Mark Lawrence wrote:
> | >I much prefer the alternative <> for != but some silly people insisted
> | >that this be removed from Python3.  Just how stupid can you get?
> |
> | So which special methods should the <> operator call?  By rights it
> | ought to call both __gt__ and __lt__ and return True if either of
> | them is True.
>
> Surely it should require both of them to be true...

Then it would never be true.  At least not for numbers.

>
> Personally I'm for != given we have ==. Aside from notational
> consistency it makes conceptual sense for unordered types, which
> <> does not really.

That's the point of mentioning __gt__ and __lt__,  they aren't available 
on unordered types.



-- 
DaveA


From cs at zip.com.au  Mon May 13 23:20:36 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Tue, 14 May 2013 13:20:36 +1000
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
In-Reply-To: <5191964D.9040900@davea.name>
References: <5191964D.9040900@davea.name>
Message-ID: <20130514032036.GA40794@cskk.homeip.net>

On 13May2013 21:41, Dave Angel <davea at davea.name> wrote:
| On 05/13/2013 07:30 PM, Cameron Simpson wrote:
| >On 13May2013 19:22, Dave Angel <davea at davea.name> wrote:
| >| On 05/13/2013 06:53 PM, Mark Lawrence wrote:
| >| >I much prefer the alternative <> for != but some silly people insisted
| >| >that this be removed from Python3.  Just how stupid can you get?
| >|
| >| So which special methods should the <> operator call?  By rights it
| >| ought to call both __gt__ and __lt__ and return True if either of
| >| them is True.
| >
| >Surely it should require both of them to be true...
| 
| Then it would never be true.  At least not for numbers.

Well that was the point. The _symbol_ looks like it should want
both. Next time I'll include the smiley.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

I really don't like :-) symbols as well. I feel that if you can't see the pie
coming, you deserve whipped cream up your nose.
        - robd at cherry.cray.com (rob derrick)


From rosuav at gmail.com  Tue May 14 03:31:41 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 14 May 2013 17:31:41 +1000
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
In-Reply-To: <519175B0.90603@davea.name>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7> <kmrqsa$uf3$1@ger.gmane.org>
	<519175B0.90603@davea.name>
Message-ID: <CAPTjJmpOCR6d5v1mY7H=zhXsLKvrMjVPSv5keRuiAA_p=DGB6Q@mail.gmail.com>

On Tue, May 14, 2013 at 9:22 AM, Dave Angel <davea at davea.name> wrote:
> On 05/13/2013 06:53 PM, Mark Lawrence wrote:
>> I much prefer the alternative <> for != but some silly people insisted
>> that this be removed from Python3.  Just how stupid can you get?
>>
>
> So which special methods should the <> operator call?  By rights it ought to
> call both __gt__ and __lt__ and return True if either of them is True.

Why do you think that? After all, the != operator doesn't call
__factorial__ and __assignment__ and return True if either is True,
does it?

ChrisA

PS. :-)


From bahamutzero8825 at gmail.com  Mon May 13 19:27:38 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Mon, 13 May 2013 18:27:38 -0500
Subject: Differences of "!=" operator behavior in python3 and python2
	[ bug? ]
In-Reply-To: <kmrqsa$uf3$1@ger.gmane.org>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7> <kmrqsa$uf3$1@ger.gmane.org>
Message-ID: <519176EA.7080502@gmail.com>

On 2013.05.13 17:53, Mark Lawrence wrote:
> I much prefer the alternative <> for != but some silly people insisted 
> that this be removed from Python3.
It's not removed from Python 3, though:

Python 3.3.1 (v3.3.1:d9893d13c628, Apr  6 2013, 20:30:21) [MSC v.1600 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from __future__ import barry_as_FLUFL
>>> 3 <> 2
True

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From ian.g.kelly at gmail.com  Mon May 13 19:32:40 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 13 May 2013 17:32:40 -0600
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
In-Reply-To: <519176EA.7080502@gmail.com>
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7> <kmrqsa$uf3$1@ger.gmane.org>
	<519176EA.7080502@gmail.com>
Message-ID: <CALwzid=gMTBmWL8joz5g1v8QNpqR4oYUTjixYh7y23acjM0tKw@mail.gmail.com>

On Mon, May 13, 2013 at 5:27 PM, Andrew Berg <bahamutzero8825 at gmail.com> wrote:
> On 2013.05.13 17:53, Mark Lawrence wrote:
>> I much prefer the alternative <> for != but some silly people insisted
>> that this be removed from Python3.
> It's not removed from Python 3, though:
>
> Python 3.3.1 (v3.3.1:d9893d13c628, Apr  6 2013, 20:30:21) [MSC v.1600 64 bit (AMD64)] on win32
> Type "help", "copyright", "credits" or "license" for more information.
>>>> from __future__ import barry_as_FLUFL
>>>> 3 <> 2
> True

I'd like to see ? added as a synonym for !=, even if nobody uses it.


From steve+comp.lang.python at pearwood.info  Tue May 14 01:09:48 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 14 May 2013 05:09:48 GMT
Subject: Differences of "!=" operator behavior in python3 and python2
	[ bug? ]
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7> <kmrqsa$uf3$1@ger.gmane.org>
	<mailman.1647.1368487365.3114.python-list@python.org>
Message-ID: <5191c71c$0$29978$c3e8da3$5496439d@news.astraweb.com>

On Mon, 13 May 2013 19:22:24 -0400, Dave Angel wrote:

> So which special methods should the <> operator call?  By rights it
> ought to call both __gt__ and __lt__ and return True if either of them
> is True.

The <> operator comes from Pascal, where it was used as "not equal" since 
ASCII doesn't include the ? operator. Algol 60, by contrast, used ? since 
it was invented before ASCII.

The use of ! as "not" is a C-ism and isn't universal.

Given the data types Pascal had as standard back when it was invented, I 
think it is fair to say that "less than, or greater than" was logically 
equivalent to "not equal to". That's no longer the case though.

Interestingly, later versions of Apple's "Standard Apple Numeric 
Environment" (SANE) included separate relational operations for "less 
than or greater than" and "not equal to". So if x was a NAN, then you 
could have pseudo-code like this:

x != y  # true

x <> y  # false



-- 
Steven


From steve+comp.lang.python at pearwood.info  Tue May 14 20:15:53 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 15 May 2013 00:15:53 GMT
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7> <kmrqsa$uf3$1@ger.gmane.org>
	<mailman.1647.1368487365.3114.python-list@python.org>
	<5191c71c$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1683.1368572505.3114.python-list@python.org>
Message-ID: <5192d3b8$0$29978$c3e8da3$5496439d@news.astraweb.com>

On Tue, 14 May 2013 19:01:38 -0400, Dennis Lee Bieber wrote:

> On 14 May 2013 05:09:48 GMT, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> declaimed the following in
> gmane.comp.python.general:

>> The <> operator comes from Pascal, where it was used as "not equal"
>> since
> 
> 	I thought it came from BASIC...
> http://en.wikipedia.org/wiki/Dartmouth_BASIC


Ah, well apparently BASIC used it earlier, but I don't know whether it 
was an influence on Pascal (except as "what not to do").


-- 
Steven


From steve+comp.lang.python at pearwood.info  Tue May 14 01:21:47 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 14 May 2013 05:21:47 GMT
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7>
Message-ID: <5191c9eb$0$29978$c3e8da3$5496439d@news.astraweb.com>

On Mon, 13 May 2013 21:17:41 +0000, Alister wrote:

> I would then still write it as not (x == y) to make it clear to myself &
> avoid any possible confusion although I think that X != Y is much
> cleaner.

I think that is sad. If I read "not (x == y)" I would assume that the 
person writing the code didn't understand Python syntax or know its 
standard operators.

The exception is if x or y was some unusual type where the __ne__ method 
does something different to the logical reverse of the __eq__ method. But 
if that is the case, I would expect a comment warning about it. If x and 
y were standard objects like floats, strings, etc. then writing out 
not (x == y) in full is as sensible as writing out these in full:

x + -y  # instead of x - y

alist.insert(len(alist), 99)  # instead of alist.append(99)

# instead of adict.clear()
for key in list(adict.keys()):
    del adict[key]

x+x+x+x+x+x  # instead of x*6


I'm sure any experienced Python programmer can come up with a 
hypothetical scenario where you would need to write things out "the long 
way", but that doesn't mean that we should do so all the time.


> 2 lines from the zen stand out here:-
> 
> Explicit is better than implicit.
> in the face of ambiguity refuse the temptation to guess.

!= is explicit.

There is no ambiguity that needs to be guessed.



-- 
Steven


From alister.ware at ntlworld.com  Wed May 15 10:41:57 2013
From: alister.ware at ntlworld.com (Alister)
Date: Wed, 15 May 2013 14:41:57 GMT
Subject: Differences of "!=" operator behavior in python3 and python2 [
	bug? ]
References: <mailman.1603.1368401007.3114.python-list@python.org>
	<HP2kt.66723$Tl3.12499@fx29.fr7>
	<CAA=1kxSJXn1_Y=oy_oxvL+mUtsZvS+FGoy-vZ39OWpbwDF07dQ@mail.gmail.com>
	<51912C27.3020809@nedbatchelder.com>
	<mailman.1641.1368470096.3114.python-list@python.org>
	<VLckt.68242$kO.37986@fx14.fr7>
	<5191c9eb$0$29978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <V8Nkt.65070$lc7.8554@fx19.fr7>

 
> != is explicit.
> 
> There is no ambiguity that needs to be guessed.

Which is why i said it thought X != Y is cleaner
i guess i wasn't totally clear, I would write  X != Y its because the OP 
preferred to use the other format I recommended that he made the operator 
ordering explicit.


-- 
Nature abhors a virgin -- a frozen asset.
		-- Clare Booth Luce


From zcbenz at gmail.com  Mon May 13 04:21:04 2013
From: zcbenz at gmail.com (zcbenz at gmail.com)
Date: Mon, 13 May 2013 01:21:04 -0700 (PDT)
Subject: How to make shutil.make_archive support symbol links?
Message-ID: <e87c2b90-5bc1-471a-8d26-8dbb7cf38722@googlegroups.com>

Hi comp.lang.python group,

I'm trying to make a zip archive with shutil.make_archive, but it seems that it doesn't support symbol links, after creating a archive with shutil.make_archive, all the symbol links would be lost.

What I want is something like `zip -y`, which "stores symbolic links as the link instead of the referenced file", is it possible to do in pure python? I also looked into the zipfile module, but it mentions no symbol links.

Thanks.

Cheng


From breamoreboy at yahoo.co.uk  Mon May 13 05:24:40 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 13 May 2013 10:24:40 +0100
Subject: Python's sad, unimaginative Enum
Message-ID: <kmqbgk$dec$1@ger.gmane.org>

That's the title of this little beast 
http://www.acooke.org/cute/Pythonssad0.html if anybody's interested.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Mon May 13 06:17:17 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 13 May 2013 10:17:17 GMT
Subject: Python's sad, unimaginative Enum
References: <mailman.1619.1368437093.3114.python-list@python.org>
Message-ID: <5190bdac$0$29978$c3e8da3$5496439d@news.astraweb.com>

On Mon, 13 May 2013 10:24:40 +0100, Mark Lawrence wrote:

> That's the title of this little beast
> http://www.acooke.org/cute/Pythonssad0.html if anybody's interested.



Well, that's one way of looking at it. And I can't exactly *disagree*.

But... but... 

  In many ways, it's a dull language, borrowing solid old concepts
  from many other languages & styles:  boring syntax, unsurprising
  semantics, few  automatic coercions, etc etc.  But that's one of
  the things I like about it.             -- Tim Peters, 16 Sep 93


Being "sad and unimaginative" is a *good thing* when it comes to syntax. 
Which would you rather read?

Python:

try:
    int(astring)
except ValueError:
    print(False)



APL:

??VFI{w???((w='-')/w)?'?'?w}


[pedant: okay, so the two code snippets are not *exactly* equivalent. So 
sue me.]


Let's look at his major criticisms:

1) values aren't automatically generated.

True. So what? That is the *least* important part of enums. The most 
important things about enums are:

- they aren't strings, but look like symbolic values;

- or they are ints (for compatibility with C libraries) that look like 
symbolic values.

Probably half the use-cases for enums are for compatibility with C 
libraries, where you *need* to specify the value. There's no point you 
defining an enum SOCK_RAW, having Python decide to set it to 7, when the 
rest of the world agrees it should have the value 3.


2) The enum implementation allows duplicates.

Yes, this *is* a feature. In the real world, enums are not unique. There 
are aliases (maybe you want FAMILY_NAME and SURNAME to be the same enum), 
and misspelled enums need to be corrected:


class Insects(Enum):
    bee = 2
    ant = 3
    wasp = 4  # Preferred spelling.
    wsap = 4  # Oops, keep this for backward compatibility!


I'm sorry for all those who can't avoid duplicating values, but really, 
Python doesn't protect them from other silly typos, why are Enums so 
special that they need to be treated differently?


3) the functional API for creating auto-numbered Enums "suffers from the 
same problems" as namedtuples:

[quote]
  - you need to repeat the class name (in a string, which your IDE is
    unlikely to check)
  - the parameters are themselves in a string, which your IDE is 
    unlikely to parse and provide in auto-complete (they can be separate
    strings, in a sequence, but that doesn't really help).
[end quote]


Then maybe you shouldn't be relying on such a lousy IDE then.

Well, perhaps I'm being a tad harsh. After all, it's not like it is a 
*feature* that namedtuple *requires* you to include the class name. But 
really, it's a trivial inconvenience. Python has much worse, e.g.:

- why aren't my CONSTANTS actually constant?


and yet somehow we survive.


4) Auto-generated enums aren't strings:

[quote]
That would makes sense (red = 'red'), in that it would display
nicely and is going to provide easy to debug values.  So nope.
[end quote]

Missing the point entirely. The *whole point* of enum red is that it WILL 
display as 'red', even though it wraps an underlying value of <whatever 
arbitrary value Python generates>. So this is a non-issue.



I think Enums will be good addition to the standard library, and I look 
forward to dropping support for Python 3.3 so I can rely on them :-)


-- 
Steven


From rosuav at gmail.com  Mon May 13 13:36:34 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 14 May 2013 03:36:34 +1000
Subject: Python's sad, unimaginative Enum
In-Reply-To: <5190bdac$0$29978$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.1619.1368437093.3114.python-list@python.org>
	<5190bdac$0$29978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmr4Ga=8E3MS+GteTvBx3JTMtcYgKb3U4N3Uy0ST0QV-7A@mail.gmail.com>

On Mon, May 13, 2013 at 8:17 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Let's look at his major criticisms:
>
> 1) values aren't automatically generated.
>
> True. So what? That is the *least* important part of enums.

I stopped following the -ideas threads about enums, but IIRC
autogeneration of values was in quite a few of the specs early on. So
you can probably find the arguments against it in the list archives.

FWIW, though, I do like C's autogeneration of enum values - but use it
in only a small proportion of my enums. It's not a terrible loss, but
it is a loss.

ChrisA


From dihedral88888 at googlemail.com  Tue May 14 21:21:36 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Tue, 14 May 2013 18:21:36 -0700 (PDT)
Subject: Python's sad, unimaginative Enum
In-Reply-To: <mailman.1635.1368466597.3114.python-list@python.org>
References: <mailman.1619.1368437093.3114.python-list@python.org>
	<5190bdac$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1635.1368466597.3114.python-list@python.org>
Message-ID: <e57951dd-7859-4439-ba3a-f29517d41d8d@googlegroups.com>

Chris Angelico? 2013?5?14????UTC+8??1?36?34????
> On Mon, May 13, 2013 at 8:17 PM, Steven D'Aprano
> 
> <steve+comp.lang.python at pearwood.info> wrote:
> 
> > Let's look at his major criticisms:
> 
> >
> 
> > 1) values aren't automatically generated.
> 
> >
> 
> > True. So what? That is the *least* important part of enums.
> 
> 
> 
> I stopped following the -ideas threads about enums, but IIRC
> 
> autogeneration of values was in quite a few of the specs early on. So
> 
> you can probably find the arguments against it in the list archives.
> 
> 
> 
> FWIW, though, I do like C's autogeneration of enum values - but use it
> 
> in only a small proportion of my enums. It's not a terrible loss, but
> 
> it is a loss.
> 
> 
> 
> ChrisA

Because a hash table can replace the enums in other languages,
it is more pythonic to use a dictionary built first
to replace the enums.

I think it is the same style of programming  in perl and ruby.


From jeanmichel at sequans.com  Mon May 13 07:00:36 2013
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Mon, 13 May 2013 13:00:36 +0200 (CEST)
Subject: Python's sad, unimaginative Enum
In-Reply-To: <kmqbgk$dec$1@ger.gmane.org>
Message-ID: <870762861.12001592.1368442836310.JavaMail.root@sequans.com>

----- Original Message -----
> That's the title of this little beast
> http://www.acooke.org/cute/Pythonssad0.html if anybody's interested.
> 
> --
> If you're using GoogleCrap? please read this
> http://wiki.python.org/moin/GoogleGroupsPython.
> 
> Mark Lawrence
> 
> --
> http://mail.python.org/mailman/listinfo/python-list
> 

python 2.5

class Enum:
  class __metaclass__(type):
    def __iter__(self):
      for attr in sorted(dir(self)):
        if not attr.startswith("__"):
          yield getattr(self, attr)

class Colours(Enum):
  RED = "red"
  GREEN = "green"

for c in Colours:
  print c

green
red


JM


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The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

From fabiosantosart at gmail.com  Tue May 14 05:33:05 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 14 May 2013 10:33:05 +0100
Subject: Python's sad, unimaginative Enum
In-Reply-To: <870762861.12001592.1368442836310.JavaMail.root@sequans.com>
References: <kmqbgk$dec$1@ger.gmane.org>
	<870762861.12001592.1368442836310.JavaMail.root@sequans.com>
Message-ID: <CAA=1kxRqQnKc=t+G-Xzy9jiozsxQByHsCQ0e7LBmhrtZ7FRmLw@mail.gmail.com>

On 13 May 2013 12:05, "Jean-Michel Pichavant" <jeanmichel at sequans.com>
wrote:
>
> class Enum:
>   class __metaclass__(type):

That's some cool metaclass fu! I didn't know that to be possible
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From steve+comp.lang.python at pearwood.info  Mon May 13 22:00:13 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 14 May 2013 02:00:13 GMT
Subject: Python's sad, unimaginative Enum
References: <mailman.1621.1368442906.3114.python-list@python.org>
Message-ID: <51919aad$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Mon, 13 May 2013 13:00:36 +0200, Jean-Michel Pichavant wrote:

> ----- Original Message -----
>> That's the title of this little beast
>> http://www.acooke.org/cute/Pythonssad0.html if anybody's interested.
>> 
>> --
>> If you're using GoogleCrap? please read this
>> http://wiki.python.org/moin/GoogleGroupsPython.
>> 
>> Mark Lawrence
>> 
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>> 
>> 
> python 2.5
> 
> class Enum:
>   class __metaclass__(type):
>     def __iter__(self):
>       for attr in sorted(dir(self)):
>         if not attr.startswith("__"):
>           yield getattr(self, attr)
> 
> class Colours(Enum):
>   RED = "red"
>   GREEN = "green"

py> class Experience(Enum):
...     NOVICE = 'novice'
...     GREEN = 'green'
...     EXPERIENCED = 'experienced'
...     MASTER = 'master'
...
py>
py> Colours.GREEN == Experience.GREEN
True


Oops.


It's very easy to make something which does a few things that enums 
should do, and call it an Enum. It's much harder to do a lot of things 
that enums should do.



-- 
Steven


From jeanmichel at sequans.com  Tue May 14 05:24:02 2013
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Tue, 14 May 2013 11:24:02 +0200 (CEST)
Subject: Python's sad, unimaginative Enum
In-Reply-To: <51919aad$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <441622996.12720717.1368523441993.JavaMail.root@sequans.com>

----- Original Message -----
> On Mon, 13 May 2013 13:00:36 +0200, Jean-Michel Pichavant wrote:
> 
> > ----- Original Message -----
> >> That's the title of this little beast
> >> http://www.acooke.org/cute/Pythonssad0.html if anybody's
> >> interested.
> >> 
> >> --
> >> If you're using GoogleCrap? please read this
> >> http://wiki.python.org/moin/GoogleGroupsPython.
> >> 
> >> Mark Lawrence
> >> 
> >> --
> >> http://mail.python.org/mailman/listinfo/python-list
> >> 
> >> 
> > python 2.5
> > 
> > class Enum:
> >   class __metaclass__(type):
> >     def __iter__(self):
> >       for attr in sorted(dir(self)):
> >         if not attr.startswith("__"):
> >           yield getattr(self, attr)
> > 
> > class Colours(Enum):
> >   RED = "red"
> >   GREEN = "green"
> 
> py> class Experience(Enum):
> ...     NOVICE = 'novice'
> ...     GREEN = 'green'
> ...     EXPERIENCED = 'experienced'
> ...     MASTER = 'master'
> ...
> py>
> py> Colours.GREEN == Experience.GREEN
> True
> 
> 
> Oops.
> 
> 
> It's very easy to make something which does a few things that enums
> should do, and call it an Enum. It's much harder to do a lot of
> things
> that enums should do.
> 
> 
> 
> --
> Steven

I was just proposing a solution I've been using and found quite satisfactory. As for the perfect "enumness" of that solution, I don't know. To be honest, I'm not sure I know the exact definition of an enum, and whether or not the C enum fits 100% that definition. It does the job in python. Some people may find it useful, others may just ignore it.
Additionally, the "bug" you mentioned can be written in C as well, casts allow to compare apples and oranges:

(Colours::GREEN == (enum Coulours::Colour)Experiences::GREEN)


JM


-- IMPORTANT NOTICE: 

The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

From rustompmody at gmail.com  Tue May 14 22:40:43 2013
From: rustompmody at gmail.com (rusi)
Date: Tue, 14 May 2013 19:40:43 -0700 (PDT)
Subject: Python's sad, unimaginative Enum
References: <mailman.1666.1368523443.3114.python-list@python.org>
Message-ID: <64ab830a-f257-4b92-a8f3-6e57981a194f@a10g2000pbr.googlegroups.com>

On May 14, 2:24?pm, Jean-Michel Pichavant <jeanmic... at sequans.com>
wrote:
> ----- Original Message -----
> > On Mon, 13 May 2013 13:00:36 +0200, Jean-Michel Pichavant wrote:
>
> > > ----- Original Message -----
> > >> That's the title of this little beast
> > >>http://www.acooke.org/cute/Pythonssad0.htmlif anybody's
> > >> interested.
>
> > >> --
> > >> If you're using GoogleCrap? please read this
> > >>http://wiki.python.org/moin/GoogleGroupsPython.
>
> > >> Mark Lawrence
>
> > >> --
> > >>http://mail.python.org/mailman/listinfo/python-list
>
> > > python 2.5
>
> > > class Enum:
> > > ? class __metaclass__(type):
> > > ? ? def __iter__(self):
> > > ? ? ? for attr in sorted(dir(self)):
> > > ? ? ? ? if not attr.startswith("__"):
> > > ? ? ? ? ? yield getattr(self, attr)
>
> > > class Colours(Enum):
> > > ? RED = "red"
> > > ? GREEN = "green"
>
> > py> class Experience(Enum):
> > ... ? ? NOVICE = 'novice'
> > ... ? ? GREEN = 'green'
> > ... ? ? EXPERIENCED = 'experienced'
> > ... ? ? MASTER = 'master'
> > ...
> > py>
> > py> Colours.GREEN == Experience.GREEN
> > True
>
> > Oops.
>
> > It's very easy to make something which does a few things that enums
> > should do, and call it an Enum. It's much harder to do a lot of
> > things
> > that enums should do.
>
> > --
> > Steven
>
> I was just proposing a solution I've been using and found quite satisfactory. As for the perfect "enumness" of that solution, I don't know. To be honest, I'm not sure I know the exact definition of an enum, and whether or not the C enum fits 100% that definition. It does the job in python. Some people may find it useful, others may just ignore it.
> Additionally, the "bug" you mentioned can be written in C as well, casts allow to compare apples and oranges:
>
> (Colours::GREEN == (enum Coulours::Colour)Experiences::GREEN)


Enums are like names.
And like names are impossible to do right:
http://www.kalzumeus.com/2010/06/17/falsehoods-programmers-believe-about-names/


From steve+comp.lang.python at pearwood.info  Mon May 13 05:20:09 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 13 May 2013 09:20:09 GMT
Subject: [Off topic] Software epigrams
Message-ID: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>

My, it's been a long time since I've seen these:

http://pu.inf.uni-tuebingen.de/users/klaeren/epigrams.html

They pre-date the Zen of Python by at least a decade, and quite frankly I 
think many of them miss the mark. But whether you agree or disagree with 
them, they're worth reading.



-- 
Steven


From marduk at python.net  Mon May 13 10:56:39 2013
From: marduk at python.net (marduk at python.net)
Date: Mon, 13 May 2013 10:56:39 -0400
Subject: [Off topic] Software epigrams
In-Reply-To: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <1368456999.30979.140661230081921.36DBAF8A@webmail.messagingengine.com>



On Mon, May 13, 2013, at 05:20 AM, Steven D'Aprano wrote:
> My, it's been a long time since I've seen these:
> 
> http://pu.inf.uni-tuebingen.de/users/klaeren/epigrams.html
> 
> They pre-date the Zen of Python by at least a decade, and quite frankly I 
> think many of them miss the mark. But whether you agree or disagree with 
> them, they're worth reading.

Yes, they're all over the place, but worth reading.  My favorite is:

101: Dealing with failure is easy: Work hard to improve. Success is also
easy to handle: You've solved the wrong problem. Work hard to improve.


From rosuav at gmail.com  Mon May 13 13:47:28 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 14 May 2013 03:47:28 +1000
Subject: [Off topic] Software epigrams
In-Reply-To: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>

On Mon, May 13, 2013 at 7:20 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> My, it's been a long time since I've seen these:
>
> http://pu.inf.uni-tuebingen.de/users/klaeren/epigrams.html
>
> They pre-date the Zen of Python by at least a decade, and quite frankly I
> think many of them miss the mark. But whether you agree or disagree with
> them, they're worth reading.

8. A programming language is low level when its programs require
attention to the irrelevant.

So much a matter of debate. Indentation is irrelevant, why should
Python programs pay attention to it? Block delimiters are irrelevant
too, the interpreter should be able to figure them out from the code
layout. But this one is absolutely right:

16. Every program has (at least) two purposes: the one for which it
was written and another for which it wasn't.

48. The best book on programming for the layman is "Alice in
Wonderland"; but that's because it's the best book on anything for the
layman.

LGTM.

ChrisA


From skip at pobox.com  Mon May 13 14:02:42 2013
From: skip at pobox.com (Skip Montanaro)
Date: Mon, 13 May 2013 13:02:42 -0500
Subject: [Off topic] Software epigrams
In-Reply-To: <CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
Message-ID: <CANc-5UwPwPKCz41e6dN+CwtVxZ7D7J0+xVy14Sb6pqkb9xWAmA@mail.gmail.com>

> 8. A programming language is low level when its programs require
> attention to the irrelevant.
>
> So much a matter of debate. Indentation is irrelevant, why should
> Python programs pay attention to it? Block delimiters are irrelevant
> too, the interpreter should be able to figure them out from the code
> layout. But this one is absolutely right:

I think "irrelevant" in this context means stuff like memory management.

My fave was #7: "It is easier to write an incorrect program than
understand a correct one," which explains in large part why the wheel
is so often reinvented...

Skip


From rosuav at gmail.com  Mon May 13 14:12:53 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 14 May 2013 04:12:53 +1000
Subject: [Off topic] Software epigrams
In-Reply-To: <CANc-5UwPwPKCz41e6dN+CwtVxZ7D7J0+xVy14Sb6pqkb9xWAmA@mail.gmail.com>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<CANc-5UwPwPKCz41e6dN+CwtVxZ7D7J0+xVy14Sb6pqkb9xWAmA@mail.gmail.com>
Message-ID: <CAPTjJmpjrsCmyJYyXFA+GM1RzcXnJKTbsiW5U_oP=3wUGmTZyQ@mail.gmail.com>

On Tue, May 14, 2013 at 4:02 AM, Skip Montanaro <skip at pobox.com> wrote:
>> 8. A programming language is low level when its programs require
>> attention to the irrelevant.
>>
>> So much a matter of debate. Indentation is irrelevant, why should
>> Python programs pay attention to it? Block delimiters are irrelevant
>> too, the interpreter should be able to figure them out from the code
>> layout. But this one is absolutely right:
>
> I think "irrelevant" in this context means stuff like memory management.

Sure. That one's pretty clear (if you care about memory management,
you want a low level language). But there's still plenty that are less
clear. Though in generalities, I think I agree; paying attention to
minutiae is the consequence of taking a lower-level language. It's
just that the difference between relevant and irrelevant is hard to
define.

ChrisA


From dan at tombstonezero.net  Mon May 13 23:08:01 2013
From: dan at tombstonezero.net (Dan Sommers)
Date: Tue, 14 May 2013 03:08:01 GMT
Subject: [Off topic] Software epigrams
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<CANc-5UwPwPKCz41e6dN+CwtVxZ7D7J0+xVy14Sb6pqkb9xWAmA@mail.gmail.com>
	<mailman.1639.1368468776.3114.python-list@python.org>
Message-ID: <lUhkt.420$iS.256@newsfe27.iad>

On Tue, 14 May 2013 04:12:53 +1000, Chris Angelico wrote:

> On Tue, May 14, 2013 at 4:02 AM, Skip Montanaro <skip at pobox.com> wrote:

>>> 8. A programming language is low level when its programs require
>>> attention to the irrelevant.

>> I think "irrelevant" in this context means stuff like memory
>> management.

> Sure. That one's pretty clear (if you care about memory management,
> you want a low level language) ...

http://www.memorymanagement.org/articles/lang.html says:

    C programmers think memory management is too important to be
    left to the computer. Lisp programmers think memory management
    is too important to be left to the user.

    (from Ellis and Stroustrup's The Annotated C++ Reference Manual)

> ... It's just that the difference between relevant and irrelevant is
> hard to define.

And if I've designed my program the right way, what's relevant in one
place (package, module, function, line of code) is different from what's
relevant in another.

Dan


From rosuav at gmail.com  Mon May 13 23:28:26 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 14 May 2013 13:28:26 +1000
Subject: [Off topic] Software epigrams
In-Reply-To: <lUhkt.420$iS.256@newsfe27.iad>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<CANc-5UwPwPKCz41e6dN+CwtVxZ7D7J0+xVy14Sb6pqkb9xWAmA@mail.gmail.com>
	<mailman.1639.1368468776.3114.python-list@python.org>
	<lUhkt.420$iS.256@newsfe27.iad>
Message-ID: <CAPTjJmow1xwmB-ni7v0K14Xt6cEjZHpTBY6ygjPKF4SA7dUxwg@mail.gmail.com>

On Tue, May 14, 2013 at 1:08 PM, Dan Sommers <dan at tombstonezero.net> wrote:
> And if I've designed my program the right way, what's relevant in one
> place (package, module, function, line of code) is different from what's
> relevant in another.

Absolutely. Layered systems FTW! Nothing matters but your current
layer and those it touches.

ChrisA


From rustompmody at gmail.com  Wed May 15 23:55:01 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 15 May 2013 20:55:01 -0700 (PDT)
Subject: Software epigrams
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<CANc-5UwPwPKCz41e6dN+CwtVxZ7D7J0+xVy14Sb6pqkb9xWAmA@mail.gmail.com>
	<mailman.1639.1368468776.3114.python-list@python.org>
	<lUhkt.420$iS.256@newsfe27.iad>
Message-ID: <cdd00250-f302-4d96-9d8a-be2383c1b234@h9g2000pbr.googlegroups.com>

On May 14, 8:08?am, Dan Sommers <d... at tombstonezero.net> wrote:
> On Tue, 14 May 2013 04:12:53 +1000, Chris Angelico wrote:
> > On Tue, May 14, 2013 at 4:02 AM, Skip Montanaro <s... at pobox.com> wrote:
> >>> 8. A programming language is low level when its programs require
> >>> attention to the irrelevant.
> >> I think "irrelevant" in this context means stuff like memory
> >> management.
> > Sure. That one's pretty clear (if you care about memory management,
> > you want a low level language) ...
>
> http://www.memorymanagement.org/articles/lang.htmlsays:
>
> ? ? C programmers think memory management is too important to be
> ? ? left to the computer. Lisp programmers think memory management
> ? ? is too important to be left to the user.
>
> ? ? (from Ellis and Stroustrup's The Annotated C++ Reference Manual)

Notable physicist David Bohm wrote that the difficulty in
understanding quantum physics is largely a result of the limitation of
the subject-predicate format of Indo-European languages.

He suggested some experiments in languaging called rheomode that makes
English more process-oriented and less (abstract)noun oriented.

One part of this project is to learn to use the word 'relevate' --
which is 'relevant' verbified with an element of 'elevate' as in 'lift
into relief'

I guess the Ellis and Stroupstrup quote above just shows that C++
programmers relevate in one direction whereas Lisp programmers
relevate in another.

More http://www.mindstructures.com/2010/04/meaning-and-context/

Twenty two years ago I wrote about this http://www.the-magus.in/Publications/chor.pdf

Suddenly I am finding glowing references to this
http://dieswaytoofast.blogspot.in/2013/01/why-i-grown-to-loathe-c.html

And I am uneasy because these questions are far less rhetorical/
tautological than I imagines in 1990!

So here's a (rather incomplete/preliminary) rebuttal to myself
http://blog.languager.org/2013/02/c-in-education-and-software-engineering.html


From neilc at norwich.edu  Mon May 13 14:42:28 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 13 May 2013 18:42:28 GMT
Subject: [Off topic] Software epigrams
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
Message-ID: <avcqgkFbdrbU1@mid.individual.net>

On 2013-05-13, Skip Montanaro <skip at pobox.com> wrote:
>> 8. A programming language is low level when its programs
>> require attention to the irrelevant.
>>
>> So much a matter of debate. Indentation is irrelevant, why
>> should Python programs pay attention to it? Block delimiters
>> are irrelevant too, the interpreter should be able to figure
>> them out from the code layout. But this one is absolutely
>> right:
>
> I think "irrelevant" in this context means stuff like memory
> management.

I thought I liked that one at first, but upon reflection it
speciously inserts the word "irrelevant" in order to avoid
stating a tautology: A programming language is low level when its
programs require attention to low level details.

-- 
Neil Cerutti


From fabiosantosart at gmail.com  Mon May 13 16:49:23 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 13 May 2013 21:49:23 +0100
Subject: [Off topic] Software epigrams
In-Reply-To: <avcqgkFbdrbU1@mid.individual.net>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
	<avcqgkFbdrbU1@mid.individual.net>
Message-ID: <CAA=1kxR2VNZhRZRvr+H_=3J7mUiVAmdSzjzt-OMvGuNYug7cWw@mail.gmail.com>

On 13 May 2013 19:48, "Neil Cerutti" <neilc at norwich.edu> wrote:
>
> On 2013-05-13, Skip Montanaro <skip at pobox.com> wrote:
> >> 8. A programming language is low level when its programs
> >> require attention to the irrelevant.
> >>
> >> So much a matter of debate. Indentation is irrelevant, why
> >> should Python programs pay attention to it? Block delimiters
> >> are irrelevant too, the interpreter should be able to figure
> >> them out from the code layout. But this one is absolutely
> >> right:
> >
> > I think "irrelevant" in this context means stuff like memory
> > management.
>
> I thought I liked that one at first, but upon reflection it
> speciously inserts the word "irrelevant" in order to avoid
> stating a tautology: A programming language is low level when its
> programs require attention to low level details.
>
> --
> Neil Cerutti
> --
> http://mail.python.org/mailman/listinfo/python-list

It's not a tautology in disguise. Irrelevant != low level. When low level
details are relevant to the scope of my program, I use a low level language.
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From neilc at norwich.edu  Wed May 15 13:24:29 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 15 May 2013 17:24:29 GMT
Subject: [Off topic] Software epigrams
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
	<avcqgkFbdrbU1@mid.individual.net>
	<mailman.1642.1368478473.3114.python-list@python.org>
Message-ID: <avhumdFft7tU1@mid.individual.net>

On 2013-05-13, F?bio Santos <fabiosantosart at gmail.com> wrote:
>
> On 13 May 2013 19:48, "Neil Cerutti" <neilc at norwich.edu> wrote:
>>
>> On 2013-05-13, Skip Montanaro <skip at pobox.com> wrote:
>> >> 8. A programming language is low level when its programs
>> >> require attention to the irrelevant.
>> >>
>> >> So much a matter of debate. Indentation is irrelevant, why
>> >> should Python programs pay attention to it? Block delimiters
>> >> are irrelevant too, the interpreter should be able to figure
>> >> them out from the code layout. But this one is absolutely
>> >> right:
>> >
>> > I think "irrelevant" in this context means stuff like memory
>> > management.
>>
>> I thought I liked that one at first, but upon reflection it
>> speciously inserts the word "irrelevant" in order to avoid
>> stating a tautology: A programming language is low level when its
>> programs require attention to low level details.
>>
>> --
>> Neil Cerutti
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
> It's not a tautology in disguise. Irrelevant != low level. When
> low level details are relevant to the scope of my program, I
> use a low level language.

It is a tautology is disguise. When you use a low level language,
low level details are relevant to the scope of your program.

-- 
Neil Cerutti


From fabiosantosart at gmail.com  Wed May 15 13:49:34 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Wed, 15 May 2013 18:49:34 +0100
Subject: [Off topic] Software epigrams
In-Reply-To: <CAA=1kxR+Syu=TUY17EMkgn-+hUnZMOdmrkfi6gZ5OOTpVf1aNg@mail.gmail.com>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
	<avcqgkFbdrbU1@mid.individual.net>
	<mailman.1642.1368478473.3114.python-list@python.org>
	<avhumdFft7tU1@mid.individual.net>
	<CAA=1kxR+Syu=TUY17EMkgn-+hUnZMOdmrkfi6gZ5OOTpVf1aNg@mail.gmail.com>
Message-ID: <CAA=1kxQbLaaG83ZkRmQHJ7WpBzbALsMhVqDFcGsKFdbybJcUEA@mail.gmail.com>

On 15 May 2013 18:29, "Neil Cerutti" <neilc at norwich.edu> wrote:
>
> On 2013-05-13, F?bio Santos <fabiosantosart at gmail.com> wrote:
> >
> > On 13 May 2013 19:48, "Neil Cerutti" <neilc at norwich.edu> wrote:
> >>
> >> On 2013-05-13, Skip Montanaro <skip at pobox.com> wrote:
> >> >> 8. A programming language is low level when its programs
> >> >> require attention to the irrelevant.
> >> >>

(...)

> > It's not a tautology in disguise. Irrelevant != low level. When
> > low level details are relevant to the scope of my program, I
> > use a low level language.
>
> It is a tautology is disguise. When you use a low level language,
> low level details are relevant to the scope of your program.
>
> --
> Neil Cerutti
> --
> http://mail.python.org/mailman/listinfo/python-list

I don't see it that way. I think relevance and level are two unrelated
concepts.

For example, in python you are handling irrelevant things if you are trying
to start a program and redirecting its standard output into another
program's standard input instead of just using the shell and a pipe to do
it.

And in C you are just at the right level to write something for a
microchip, but then again you are doing a load of irrelevant stuff if you
need to work numbers larger than the maximum permitted.
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From neilc at norwich.edu  Wed May 15 14:27:39 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 15 May 2013 18:27:39 GMT
Subject: [Off topic] Software epigrams
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
	<avcqgkFbdrbU1@mid.individual.net>
	<mailman.1642.1368478473.3114.python-list@python.org>
	<avhumdFft7tU1@mid.individual.net>
	<CAA=1kxR+Syu=TUY17EMkgn-+hUnZMOdmrkfi6gZ5OOTpVf1aNg@mail.gmail.com>
	<mailman.1712.1368640178.3114.python-list@python.org>
Message-ID: <avi2crFggb1U1@mid.individual.net>

On 2013-05-15, F?bio Santos <fabiosantosart at gmail.com> wrote:
>> It is a tautology is disguise. When you use a low level
>> language, low level details are relevant to the scope of your
>> program.
>
> I don't see it that way. I think relevance and level are two
> unrelated concepts.
>
> For example, in python you are handling irrelevant things if
> you are trying to start a program and redirecting its standard
> output into another program's standard input instead of just
> using the shell and a pipe to do it.
>
> And in C you are just at the right level to write something for
> a microchip, but then again you are doing a load of irrelevant
> stuff if you need to work numbers larger than the maximum
> permitted.

If you need numbers larger than the maximum permitted then all
the code you write to handle them is relevant.

If I want to bake bread I hope I don't have to till a garden,
plant the wheat, harvest the wheat, and grind the wheat. But
gardening is relevant to bread baking weather or not I do it.

-- 
Neil Cerutti


From fabiosantosart at gmail.com  Wed May 15 20:21:52 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 16 May 2013 01:21:52 +0100
Subject: [Off topic] Software epigrams
In-Reply-To: <avi2crFggb1U1@mid.individual.net>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
	<avcqgkFbdrbU1@mid.individual.net>
	<mailman.1642.1368478473.3114.python-list@python.org>
	<avhumdFft7tU1@mid.individual.net>
	<CAA=1kxR+Syu=TUY17EMkgn-+hUnZMOdmrkfi6gZ5OOTpVf1aNg@mail.gmail.com>
	<mailman.1712.1368640178.3114.python-list@python.org>
	<avi2crFggb1U1@mid.individual.net>
Message-ID: <CAA=1kxRykgk9e+QoeoTSW93+nMP1qo81NoDaXA6Tua+vf8+Ejg@mail.gmail.com>

On 15 May 2013 19:33, "Neil Cerutti" <neilc at norwich.edu> wrote:
>
> On 2013-05-15, F?bio Santos <fabiosantosart at gmail.com> wrote:
> >> It is a tautology is disguise. When you use a low level
> >> language, low level details are relevant to the scope of your
> >> program.
> >
> > I don't see it that way. I think relevance and level are two
> > unrelated concepts.
> >
> > For example, in python you are handling irrelevant things if
> > you are trying to start a program and redirecting its standard
> > output into another program's standard input instead of just
> > using the shell and a pipe to do it.
> >
> > And in C you are just at the right level to write something for
> > a microchip, but then again you are doing a load of irrelevant
> > stuff if you need to work numbers larger than the maximum
> > permitted.
>
> If you need numbers larger than the maximum permitted then all
> the code you write to handle them is relevant.
>
> If I want to bake bread I hope I don't have to till a garden,
> plant the wheat, harvest the wheat, and grind the wheat. But
> gardening is relevant to bread baking weather or not I do it.
>
> --
> Neil Cerutti
> --
> http://mail.python.org/mailman/listinfo/python-list

Then memory management t is relevant to every python program even though
it's done by the interpreter?

And in Java we have factories, builders and builderfactories. What's so
relevant about them? Java is high level, no?
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From neilc at norwich.edu  Thu May 16 10:23:28 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 16 May 2013 14:23:28 GMT
Subject: [Off topic] Software epigrams
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
	<avcqgkFbdrbU1@mid.individual.net>
	<mailman.1642.1368478473.3114.python-list@python.org>
	<avhumdFft7tU1@mid.individual.net>
	<CAA=1kxR+Syu=TUY17EMkgn-+hUnZMOdmrkfi6gZ5OOTpVf1aNg@mail.gmail.com>
	<mailman.1712.1368640178.3114.python-list@python.org>
	<avi2crFggb1U1@mid.individual.net>
	<mailman.1726.1368663721.3114.python-list@python.org>
Message-ID: <avk8f0Fs40U1@mid.individual.net>

On 2013-05-16, F?bio Santos <fabiosantosart at gmail.com> wrote:
>> If I want to bake bread I hope I don't have to till a garden,
>> plant the wheat, harvest the wheat, and grind the wheat. But
>> gardening is relevant to bread baking weather or not I do it.
>
> Then memory management t is relevant to every python program
> even though it's done by the interpreter?

Yes, I think so. If you didn't understand how Python managed
memory, you couldn't write it effectively. You would end up
making unecessary copies, and other pathological programming
practices.

> And in Java we have factories, builders and builderfactories.
> What's so relevant about them? Java is high level, no?

When I tried to pin down what an irrelevant detail in a computer
program could be, I couldn't do it. I guess comment decorations,
maybe? But those would have no bearing on the level of problem
for which a programming language is most appropriate.

-- 
Neil Cerutti


From rosuav at gmail.com  Thu May 16 10:37:31 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 17 May 2013 00:37:31 +1000
Subject: [Off topic] Software epigrams
In-Reply-To: <avk8f0Fs40U1@mid.individual.net>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
	<avcqgkFbdrbU1@mid.individual.net>
	<mailman.1642.1368478473.3114.python-list@python.org>
	<avhumdFft7tU1@mid.individual.net>
	<CAA=1kxR+Syu=TUY17EMkgn-+hUnZMOdmrkfi6gZ5OOTpVf1aNg@mail.gmail.com>
	<mailman.1712.1368640178.3114.python-list@python.org>
	<avi2crFggb1U1@mid.individual.net>
	<mailman.1726.1368663721.3114.python-list@python.org>
	<avk8f0Fs40U1@mid.individual.net>
Message-ID: <CAPTjJmpiS5osaHd4ncaVk6OofQMXxmfnBLtHsO6rcBpcy5_73A@mail.gmail.com>

On Fri, May 17, 2013 at 12:23 AM, Neil Cerutti <neilc at norwich.edu> wrote:
> On 2013-05-16, F?bio Santos <fabiosantosart at gmail.com> wrote:
>> And in Java we have factories, builders and builderfactories.
>> What's so relevant about them? Java is high level, no?
>
> When I tried to pin down what an irrelevant detail in a computer
> program could be, I couldn't do it. I guess comment decorations,
> maybe? But those would have no bearing on the level of problem
> for which a programming language is most appropriate.

Let me give you a real example.

One of the programs I wrote at work is a simple daemon that runs on
every node in a network. It periodically sends out a heartbeat signal
that the other nodes hear, and if any node hasn't been heard from in X
seconds, it is deemed "down". (It might technically not be down, if
there's a network problem, but the point is that we don't care about
the difference. It's down.) There's also some incidental statussy data
included, for convenience. This is implemented using UDP.

Do I care about how a UDP packet is structured? No.

Do I care about the mechanics of IP routing? No.

Do I care about MAC addresses? No. They might feature in our IPv6
addresses, but I still don't care - the IP addresses (v4 or v6) of the
nodes are treated as opaque tokens.

All I care about is that I call a function with a string of data and a
corresponding function gets called in the other program with that same
string. All the details of how that happens in between aren't
important to my program. They're somewhat of note in the design phase,
but not to the program itself. They are, in fact, irrelevant.

ChrisA


From rustompmody at gmail.com  Thu May 16 11:06:10 2013
From: rustompmody at gmail.com (rusi)
Date: Thu, 16 May 2013 08:06:10 -0700 (PDT)
Subject: Software epigrams
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
	<avcqgkFbdrbU1@mid.individual.net>
	<mailman.1642.1368478473.3114.python-list@python.org>
	<avhumdFft7tU1@mid.individual.net>
	<CAA=1kxR+Syu=TUY17EMkgn-+hUnZMOdmrkfi6gZ5OOTpVf1aNg@mail.gmail.com>
	<mailman.1712.1368640178.3114.python-list@python.org>
	<avi2crFggb1U1@mid.individual.net>
	<mailman.1726.1368663721.3114.python-list@python.org>
	<avk8f0Fs40U1@mid.individual.net>
	<mailman.1754.1368715060.3114.python-list@python.org>
Message-ID: <2a8e503f-50c0-4d13-8ea3-c310575c977e@wg15g2000pbb.googlegroups.com>

On May 16, 7:37?pm, Chris Angelico <ros... at gmail.com> wrote:
> On Fri, May 17, 2013 at 12:23 AM, Neil Cerutti <ne... at norwich.edu> wrote:
> > On 2013-05-16, F?bio Santos <fabiosantos... at gmail.com> wrote:
> >> And in Java we have factories, builders and builderfactories.
> >> What's so relevant about them? Java is high level, no?
>
> > When I tried to pin down what an irrelevant detail in a computer
> > program could be, I couldn't do it. I guess comment decorations,
> > maybe? But those would have no bearing on the level of problem
> > for which a programming language is most appropriate.
>
> Let me give you a real example.
>
> One of the programs I wrote at work is a simple daemon that runs on
> every node in a network. It periodically sends out a heartbeat signal
> that the other nodes hear, and if any node hasn't been heard from in X
> seconds, it is deemed "down". (It might technically not be down, if
> there's a network problem, but the point is that we don't care about
> the difference. It's down.) There's also some incidental statussy data
> included, for convenience. This is implemented using UDP.
>
> Do I care about how a UDP packet is structured? No.
>
> Do I care about the mechanics of IP routing? No.
>
> Do I care about MAC addresses? No. They might feature in our IPv6
> addresses, but I still don't care - the IP addresses (v4 or v6) of the
> nodes are treated as opaque tokens.
>
> All I care about is that I call a function with a string of data and a
> corresponding function gets called in the other program with that same
> string. All the details of how that happens in between aren't
> important to my program. They're somewhat of note in the design phase,
> but not to the program itself. They are, in fact, irrelevant.
>
> ChrisA

You are just saying (in specific detail) what I said, viz that the
programmer is one who 'relevates' ie sifts the relevant from the
irrelevant and a good programming language is one that gives good
relevating tools:
http://blog.languager.org/2013/02/c-in-education-and-software-engineering.html


From rosuav at gmail.com  Thu May 16 11:19:38 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 17 May 2013 01:19:38 +1000
Subject: Software epigrams
In-Reply-To: <2a8e503f-50c0-4d13-8ea3-c310575c977e@wg15g2000pbb.googlegroups.com>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmr-HxE90KbA-VQvwHGdn9soQOfV9+b9coGZ_rrh6O4T4w@mail.gmail.com>
	<mailman.1637.1368468166.3114.python-list@python.org>
	<avcqgkFbdrbU1@mid.individual.net>
	<mailman.1642.1368478473.3114.python-list@python.org>
	<avhumdFft7tU1@mid.individual.net>
	<CAA=1kxR+Syu=TUY17EMkgn-+hUnZMOdmrkfi6gZ5OOTpVf1aNg@mail.gmail.com>
	<mailman.1712.1368640178.3114.python-list@python.org>
	<avi2crFggb1U1@mid.individual.net>
	<mailman.1726.1368663721.3114.python-list@python.org>
	<avk8f0Fs40U1@mid.individual.net>
	<mailman.1754.1368715060.3114.python-list@python.org>
	<2a8e503f-50c0-4d13-8ea3-c310575c977e@wg15g2000pbb.googlegroups.com>
Message-ID: <CAPTjJmoRUg7iZvxG3FNc55Wx_3c=4-a8LYx2Amht9ZUkAknr=Q@mail.gmail.com>

On Fri, May 17, 2013 at 1:06 AM, rusi <rustompmody at gmail.com> wrote:
> On May 16, 7:37 pm, Chris Angelico <ros... at gmail.com> wrote:
>> On Fri, May 17, 2013 at 12:23 AM, Neil Cerutti <ne... at norwich.edu> wrote:
>> > When I tried to pin down what an irrelevant detail in a computer
>> > program could be, I couldn't do it. I guess comment decorations,
>> > maybe? But those would have no bearing on the level of problem
>> > for which a programming language is most appropriate.
>>
>> Let me give you a real example.
>> [snip]
>
> You are just saying (in specific detail) what I said, viz that the
> programmer is one who 'relevates' ie sifts the relevant from the
> irrelevant and a good programming language is one that gives good
> relevating tools:
> http://blog.languager.org/2013/02/c-in-education-and-software-engineering.html

Right. All I'm adding is a concrete example - which, I think, will be
helpful to Neil, and perhaps to others too.

ChrisA


From inq1ltd at inqvista.com  Wed May 15 16:56:01 2013
From: inq1ltd at inqvista.com (inq1ltd)
Date: Wed, 15 May 2013 16:56:01 -0400
Subject: python 2.7 vs 2.5
In-Reply-To: <avhumdFft7tU1@mid.individual.net>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1642.1368478473.3114.python-list@python.org>
	<avhumdFft7tU1@mid.individual.net>
Message-ID: <4773190.v3vY0HWMWS@mach-114-20>

My web server is using python 2.5.

My cgi file is trying to open a shelve.

I xxx out some of the path below. 

I am trying to find out if this 
error is caused because I am using python 2.7 to write 
the cgi file and my web server is using python 2.5.

I would appreciate a confirmation of this.

 line 85, in FentriesFilled dbase = shelve.open( vpath, 'c' ) File 
"/usr/local/lib/python-2.5/lib/python2.5/shelve.py", line 225, in open return 
DbfilenameShelf(filename, flag, protocol, writeback) File 
"/usr/local/lib/python-2.5/lib/python2.5/shelve.py",

 line 209, in __init__ Shelf.__init__(self, anydbm.open(filename, flag), 
protocol, writeback) File "/usr/local/lib/python-2.5/lib/python2.5/anydbm.py", 
line 83, in open return mod.open(file, flag, mode) 

File "/usr/local/lib/python-2.5/lib/python2.5/dbhash.py", line 16, in open 
return bsddb.hashopen(file, flag, mode) 

File "/usr/local/lib/python-2.5/lib/python2.5/bsddb/__init__.py", line 306, in 
hashopen d.open(file, db.DB_HASH, flags, mode) bsddb.db.DBInvalidArgError: 
(22, 'Invalid argument --/home/users/web/xxxxx/yyy.inqvista/public_html/xxxx-
ssss/email: unsupported hash version: 9') 

thanks,
jd



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From jeanmichel at sequans.com  Thu May 16 13:17:57 2013
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Thu, 16 May 2013 19:17:57 +0200 (CEST)
Subject: python 2.7 vs 2.5
In-Reply-To: <4773190.v3vY0HWMWS@mach-114-20>
Message-ID: <645094577.14849462.1368724677094.JavaMail.root@sequans.com>


----- Original Message ----- 

>I am using python 2.7 to write
> the cgi file and my web server is using python 2.5.

The answer lies in your question.

JM


-- IMPORTANT NOTICE: 

The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

From inq1ltd at inqvista.com  Thu May 16 17:21:04 2013
From: inq1ltd at inqvista.com (inq1ltd)
Date: Thu, 16 May 2013 17:21:04 -0400
Subject: python 2.7 vs 2.5
In-Reply-To: <645094577.14849462.1368724677094.JavaMail.root@sequans.com>
References: <645094577.14849462.1368724677094.JavaMail.root@sequans.com>
Message-ID: <59526395.mz35FTIYGg@mach-114-20>

On Thursday, May 16, 2013 07:17:57 PM Jean-Michel Pichavant wrote:
> ----- Original Message -----
> 
> >I am using python 2.7 to write
> >
> > the cgi file and my web server is using python 2.5.
> 
> The answer lies in your question.
> 
> JM
> 

I appreciate the response,

However, My question was wrong.  

The traceback I got
couldn't be because of a difference in versions
because I programmed the cgi on the site. 

I found that the path to the cgi had to be complete,
something like this:

/home/users/web/xxx/yyy.inqvista/public_html/home/read/mail

anything else gets a traceback.

jd

 









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From inq1ltd at inqvista.com  Thu May 30 15:48:20 2013
From: inq1ltd at inqvista.com (inq1ltd)
Date: Thu, 30 May 2013 15:48:20 -0400
Subject: sendmail smtplib.SMTP('localhost') Where is the email?
In-Reply-To: <4773190.v3vY0HWMWS@mach-114-20>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<avhumdFft7tU1@mid.individual.net> <4773190.v3vY0HWMWS@mach-114-20>
Message-ID: <7572490.mfSH6Zg6jY@mach-114-20>

python help,

I've tried this code which I got from:
http://www.tutorialspoint.com/python/python_sending_email.htm


I build this file and run it 
---//---

#!/usr/bin/python
 
import smtplib
sender = "inq1ltd at inqvista.com"
receivers = ["webmaster at inqvista.com"]

message = """From: jol
To: webmaster 
Subject: SMTP e-mail test

This is a test e-mail message.
"""

try:
   smtpObj = smtplib.SMTP('localhost')
   smtpObj.sendmail(sender, receivers, message)
   print "Successfully sent email"
except SMTPException:
   print "Error: unable to send email" 

--//--

After running the the file and I get 
"Successfully sent email"

My question is why doesn't webmaster get an email?

jol









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From rosuav at gmail.com  Thu May 30 18:13:53 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 08:13:53 +1000
Subject: sendmail smtplib.SMTP('localhost') Where is the email?
In-Reply-To: <7572490.mfSH6Zg6jY@mach-114-20>
References: <5190b049$0$29978$c3e8da3$5496439d@news.astraweb.com>
	<avhumdFft7tU1@mid.individual.net> <4773190.v3vY0HWMWS@mach-114-20>
	<7572490.mfSH6Zg6jY@mach-114-20>
Message-ID: <CAPTjJmpjnnFD3e2ngroSpkkc7nK4NiBp8k-yJP7O23nCg-mBtw@mail.gmail.com>

On Fri, May 31, 2013 at 5:48 AM, inq1ltd <inq1ltd at inqvista.com> wrote:
> python help,
>
> I've tried this code which I got from:
>
> http://www.tutorialspoint.com/python/python_sending_email.htm
>
> I build this file and run it
>
> After running the the file and I get
>
> "Successfully sent email"
>
> My question is why doesn't webmaster get an email?

First point: Please send *plain text* emails. Your message came out
double-spaced and with absolutely no indentation, which destroys the
structure of Python code. (Your script is sufficiently simple that
it's fairly clear how it had to be laid out, but when you force us to
use our crystal balls for simple stuff like indentation, we can't use
them again for something more important. The cooldown on these babies
is pretty stiff sometimes.)

Secondly, it helps a LOT to tell us what you're running under - Python
version, OS, etc. One easy way to do that is to quote the text that
the interactive interpreter opens with, eg:

Python 2.4.5 (#1, Jul 22 2011, 02:01:04)
[GCC 4.1.1] on mingw32

Python 3.4.0a0 (default:5dcd7ee0716a, Mar 30 2013, 08:17:06)
[GCC 4.7.2] on linux

Now, on to your actual code.

The docs say:
"""This method will return normally if the mail is accepted for at
least one recipient. Otherwise it will raise an exception. That is, if
this method does not raise an exception, then someone should get your
mail."""

That's nice confidence-inducing language, but I take exception (if
you'll pardon the pun) to the last part. The only thing this function
can know is that the mail has been accepted by the next hop. After
that... well, the internet is a scary place, anything could happen.
See if your SMTP server (the one running on localhost) has a nice log;
you may be able to watch the message get processed by the next hop.

By the way, I wouldn't bother with the try/except here. Just let the
exception bubble up and be emitted to stderr. It'll be more useful
that way :)

ChrisA


From cs at zip.com.au  Thu May 30 18:55:12 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Fri, 31 May 2013 08:55:12 +1000
Subject: sendmail smtplib.SMTP('localhost') Where is the email?
In-Reply-To: <7572490.mfSH6Zg6jY@mach-114-20>
References: <7572490.mfSH6Zg6jY@mach-114-20>
Message-ID: <20130530225512.GA60695@cskk.homeip.net>

On 30May2013 15:48, inq1ltd <inq1ltd at inqvista.com> wrote:
| python help,

Please do not make new discussions by replying to an old discussion.

It is not enough to change the subject line; unless you also remove
any References: and In-Reply-To: header lines your message is still
considered part of the old discussion.

| I've tried this code which I got from:
| http://www.tutorialspoint.com/python/python_sending_email.htm
| 
| I build this file and run it 
[...]
|    smtpObj = smtplib.SMTP('localhost')
|    smtpObj.sendmail(sender, receivers, message)
|    print "Successfully sent email"
[...]
| After running the the file and I get 
| "Successfully sent email"
| 
| My question is why doesn't webmaster get an email?

Well, this suggests that the message has been accepted by the mail
system on localhost. Not that final delivery was made anywhere else.

You now have to read the log files on your mail system to see what happened.

One easy check to do first is to see if it is still in your mail
system but undelivered. On a UNIX system running the command:

  mailq

should tell you that. If the queue is empty, the message has been
sent somewhere and you must dig through the logs to find out where.
If the message is in the queue then the "mailq" command will probably
give a suggestion as to why.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

As you can see, unraveling even a small part of 'sendmail' can introduce more
complexity than answers.        - Brian Costales, _sendmail_


From inq1ltd at inqvista.com  Fri May 31 12:07:58 2013
From: inq1ltd at inqvista.com (inq1ltd)
Date: Fri, 31 May 2013 12:07:58 -0400
Subject: sendmail smtplib.SMTP('localhost') Where is the email?
In-Reply-To: <20130530225512.GA60695@cskk.homeip.net>
References: <7572490.mfSH6Zg6jY@mach-114-20>
	<20130530225512.GA60695@cskk.homeip.net>
Message-ID: <1713012.pPmM7KcTts@mach-114-20>


Your responses helped.

The mailg for linux gave me information I didn't expect.

regards,
jol







On Friday, May 31, 2013 08:55:12 AM Cameron Simpson wrote:
> On 30May2013 15:48, inq1ltd <inq1ltd at inqvista.com> wrote:
> | python help,
> 
> Please do not make new discussions by replying to an old discussion.
> 
> It is not enough to change the subject line; unless you also remove
> any References: and In-Reply-To: header lines your message is still
> considered part of the old discussion.
> 
> | I've tried this code which I got from:
> | http://www.tutorialspoint.com/python/python_sending_email.htm
> | 
> | I build this file and run it
> 
> [...]
> 
> |    smtpObj = smtplib.SMTP('localhost')
> |    smtpObj.sendmail(sender, receivers, message)
> |    print "Successfully sent email"
> 
> [...]
> 
> | After running the the file and I get
> | "Successfully sent email"
> | 
> | My question is why doesn't webmaster get an email?
> 
> Well, this suggests that the message has been accepted by the mail
> system on localhost. Not that final delivery was made anywhere else.
> 
> You now have to read the log files on your mail system to see what happened.
> 
> One easy check to do first is to see if it is still in your mail
> system but undelivered. On a UNIX system running the command:
> 
>   mailq
> 
> should tell you that. If the queue is empty, the message has been
> sent somewhere and you must dig through the logs to find out where.
> If the message is in the queue then the "mailq" command will probably
> give a suggestion as to why.
> 
> Cheers,
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From feather.duster.kung.fu at gmail.com  Mon May 13 10:02:28 2013
From: feather.duster.kung.fu at gmail.com (feather.duster.kung.fu at gmail.com)
Date: Mon, 13 May 2013 07:02:28 -0700 (PDT)
Subject: global variable not working inside function. Increment
In-Reply-To: <dd059a77-f845-40ae-9e95-20731b34f512@a39g2000pre.googlegroups.com>
References: <dd059a77-f845-40ae-9e95-20731b34f512@a39g2000pre.googlegroups.com>
Message-ID: <7a4886ba-482d-4edc-a186-a9dc2a1e3714@googlegroups.com>

On Friday, September 4, 2009 4:43:27 PM UTC-7, Helvin wrote:
> Hi,
> 
> This increment thing is driving me nearly to the nuts-stage. > <
> 
> I have a function that allows me to pick points. I want to count the
> number of times I have picked points.
> 
>     global no_picked
>     no_picked = 0
> 
>     def picked(object, event):
>           no_picked += 1
>           print no_picked
> 
> Error msg says: UnboundLocalError: local variable 'no_picked'
> referenced before assignment
> For some reason, no_picked does not increment, but the printing
> statement works.
> 
> Do you know why?
> 
> (I'm actually writing this for a vtkrenderwindowinteractor.)
> 
> Helvin



From feather.duster.kung.fu at gmail.com  Mon May 13 10:10:50 2013
From: feather.duster.kung.fu at gmail.com (charles benoit)
Date: Mon, 13 May 2013 07:10:50 -0700 (PDT)
Subject: global variable not working inside function. Increment
In-Reply-To: <mailman.990.1252108333.2854.python-list@python.org>
References: <dd059a77-f845-40ae-9e95-20731b34f512@a39g2000pre.googlegroups.com>
	<mailman.990.1252108333.2854.python-list@python.org>
Message-ID: <4c334b0e-88ba-43b1-9201-7a2ef5a270fe@googlegroups.com>

On Friday, September 4, 2009 4:52:11 PM UTC-7, Rami Chowdhury wrote:
> >     global no_picked
> >     no_picked = 0
> >
> >     def picked(object, event):
> >           no_picked += 1
> >           print no_picked
> 
> In order to be able to affect variables in the global scope, you need to  
> declare them global inside the function, and not at the global scope. So  
> your code should read:
> 
> 	no_picked = 0
> 
> 	def picked(object, event):
> 		global no_picked
> 		no_picked += 1
> 		print no_picked
> 
> I believe that will work.
> 
> On Fri, 04 Sep 2009 16:43:27 -0700, Helvin <helvinlui at gmail.com> wrote:
> 
> > Hi,
> >
> > This increment thing is driving me nearly to the nuts-stage. > <
> >
> > I have a function that allows me to pick points. I want to count the
> > number of times I have picked points.
> >
> >     global no_picked
> >     no_picked = 0
> >
> >     def picked(object, event):
> >           no_picked += 1
> >           print no_picked
> >
> > Error msg says: UnboundLocalError: local variable 'no_picked'
> > referenced before assignment
> > For some reason, no_picked does not increment, but the printing
> > statement works.
> >
> > Do you know why?
> >
> > (I'm actually writing this for a vtkrenderwindowinteractor.)
> >
> > Helvin
> 
> 
> 
> -- 
> Rami Chowdhury
> "Never attribute to malice that which can be attributed to stupidity" --  
> Hanlon's Razor
> 408-597-7068 (US) / 07875-841-046 (UK) / 0189-245544 (BD)



From feather.duster.kung.fu at gmail.com  Mon May 13 10:25:40 2013
From: feather.duster.kung.fu at gmail.com (feather.duster.kung.fu)
Date: Mon, 13 May 2013 07:25:40 -0700 (PDT)
Subject: global variable not working inside function. Increment
In-Reply-To: <4c334b0e-88ba-43b1-9201-7a2ef5a270fe@googlegroups.com>
References: <dd059a77-f845-40ae-9e95-20731b34f512@a39g2000pre.googlegroups.com>
	<mailman.990.1252108333.2854.python-list@python.org>
	<4c334b0e-88ba-43b1-9201-7a2ef5a270fe@googlegroups.com>
Message-ID: <688b6146-4601-47a7-8418-5fbc28650307@googlegroups.com>

On Monday, May 13, 2013 7:10:50 AM UTC-7, charles benoit wrote:
> On Friday, September 4, 2009 4:52:11 PM UTC-7, Rami Chowdhury wrote:
> 
> > >     global no_picked
> 
> > >     no_picked = 0
> 
> > >
> 
> > >     def picked(object, event):
> 
> > >           no_picked += 1
> 
> > >           print no_picked
> 
> > 
> 
> > In order to be able to affect variables in the global scope, you need to  
> 
> > declare them global inside the function, and not at the global scope. So  
> 
> > your code should read:
> 
> > 
> 
> > 	no_picked = 0
> 
> > 
> 
> > 	def picked(object, event):
> 
> > 		global no_picked
> 
> > 		no_picked += 1
> 
> > 		print no_picked
> 
> > 
> 
> > I believe that will work.
> 
> > 
> 
> > On Fri, 04 Sep 2009 16:43:27 -0700, Helvin <helvinlui at gmail.com> wrote:
> 
> > 
> 
> > > Hi,
> 
> > >
> 
> > > This increment thing is driving me nearly to the nuts-stage. > <
> 
> > >
> 
> > > I have a function that allows me to pick points. I want to count the
> 
> > > number of times I have picked points.
> 
> > >
> 
> > >     global no_picked
> 
> > >     no_picked = 0
> 
> > >
> 
> > >     def picked(object, event):
> 
> > >           no_picked += 1
> 
> > >           print no_picked
> 
> > >
> 
> > > Error msg says: UnboundLocalError: local variable 'no_picked'
> 
> > > referenced before assignment
> 
> > > For some reason, no_picked does not increment, but the printing
> 
> > > statement works.
> 
> > >
> 
> > > Do you know why?
> 
> > >
> 
> > > (I'm actually writing this for a vtkrenderwindowinteractor.)
> 
> > >
> 
> > > Helvin
> 
> > 
> 
> > 
> 
> > 
> 
> > -- 
> 
> > Rami Chowdhury
> 
> > "Never attribute to malice that which can be attributed to stupidity" --  
> 
> > Hanlon's Razor
> 
> > 408-597-7068 (US) / 07875-841-046 (UK) / 0189-245544 (BD)

Thank You for setting that straight. I'm just learning Python and NONE of the tutorials I read said anything about that . In fact they all say a global can be called from inside a Function. If possible please contact the ppl that write these things.....I've heard of Ocam's razor but not Hanlon's???


From jeanmichel at sequans.com  Mon May 13 11:07:41 2013
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Mon, 13 May 2013 17:07:41 +0200 (CEST)
Subject: global variable not working inside function. Increment
In-Reply-To: <688b6146-4601-47a7-8418-5fbc28650307@googlegroups.com>
Message-ID: <124893356.12204414.1368457661367.JavaMail.root@sequans.com>

> Thank You for setting that straight. I'm just learning Python and
> NONE of the tutorials I read said anything about that . In fact they
> all say a global can be called from inside a Function. If possible
> please contact the ppl that write these things.....I've heard of
> Ocam's razor but not Hanlon's???
> --
> http://mail.python.org/mailman/listinfo/python-list

It's covered by this one:
http://docs.python.org/2/tutorial/classes.html#python-scopes-and-namespaces

It's flagged as a quirk python behavior, and probably could afford a code sample, it can be difficult to grasp from the formal description.

JM


-- IMPORTANT NOTICE: 

The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

From andipersti at gmail.com  Mon May 13 12:13:28 2013
From: andipersti at gmail.com (Andreas Perstinger)
Date: Mon, 13 May 2013 18:13:28 +0200
Subject: global variable not working inside function. Increment
In-Reply-To: <688b6146-4601-47a7-8418-5fbc28650307@googlegroups.com>
References: <dd059a77-f845-40ae-9e95-20731b34f512@a39g2000pre.googlegroups.com>
	<mailman.990.1252108333.2854.python-list@python.org>
	<4c334b0e-88ba-43b1-9201-7a2ef5a270fe@googlegroups.com>
	<688b6146-4601-47a7-8418-5fbc28650307@googlegroups.com>
Message-ID: <20130513181328.942e8f2303ebb9fa5b592e7e@gmail.com>

"feather.duster.kung.fu" <feather.duster.kung.fu at gmail.com> wrote:
>I'm just learning Python and NONE of the tutorials I read said
>anything about that . In fact they all say a global can be called from
>inside a Function. If possible please contact the ppl that write these
>things.

Well, we don't know which tutorials you read.
So why don't you tell them yourself?

Bye, Andreas


From sharon_couka at hotmail.com  Mon May 13 11:41:51 2013
From: sharon_couka at hotmail.com (Sharon COUKA)
Date: Mon, 13 May 2013 17:41:51 +0200
Subject: Fractal 
Message-ID: <DUB406-EAS2733F3138D2284E49821C21EAA00@phx.gbl>

Hello, I'm new to python and i have to make a Mandelbrot fractal image for school but I don't know how to zoom in my image.
Thank you for helping me.

Envoy? de mon iPad

From cjw at ncf.ca  Wed May 15 08:07:03 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Wed, 15 May 2013 08:07:03 -0400
Subject: Fractal
In-Reply-To: <mailman.1691.1368602017.3114.python-list@python.org>
References: <mailman.1691.1368602017.3114.python-list@python.org>
Message-ID: <51937A67.1000702@ncf.ca>

On 13/05/2013 11:41 AM, Sharon COUKA wrote:
> Hello, I'm new to python and i have to make a Mandelbrot fractal image for school but I don't know how to zoom in my image.
> Thank you for helping me.
>
> Envoy? de mon iPad


Google is your friend.  Try "Mandelbrot Python"

Colin W.
>



From cjw at ncf.ca  Wed May 15 08:07:03 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Wed, 15 May 2013 08:07:03 -0400
Subject: Fractal
In-Reply-To: <mailman.1691.1368602017.3114.python-list@python.org>
References: <mailman.1691.1368602017.3114.python-list@python.org>
Message-ID: <51937A67.1000702@ncf.ca>

On 13/05/2013 11:41 AM, Sharon COUKA wrote:
> Hello, I'm new to python and i have to make a Mandelbrot fractal image for school but I don't know how to zoom in my image.
> Thank you for helping me.
>
> Envoy? de mon iPad


Google is your friend.  Try "Mandelbrot Python"

Colin W.
>



From wuwei23 at gmail.com  Wed May 15 20:00:24 2013
From: wuwei23 at gmail.com (alex23)
Date: Wed, 15 May 2013 17:00:24 -0700 (PDT)
Subject: Fractal
References: <mailman.1691.1368602017.3114.python-list@python.org>
	<51937A67.1000702@ncf.ca>
Message-ID: <2ce10d3b-505b-4ba6-8fae-77facfaac654@hc4g2000pbb.googlegroups.com>

On May 15, 10:07?pm, "Colin J. Williams" <c... at ncf.ca> wrote:
> Google is your friend. ?Try "Mandelbrot Python"

My favourite is this one:
http://preshing.com/20110926/high-resolution-mandelbrot-in-obfuscated-python


From ulrich.eckhardt at dominolaser.com  Thu May 16 03:11:24 2013
From: ulrich.eckhardt at dominolaser.com (Ulrich Eckhardt)
Date: Thu, 16 May 2013 09:11:24 +0200
Subject: Fractal
In-Reply-To: <2ce10d3b-505b-4ba6-8fae-77facfaac654@hc4g2000pbb.googlegroups.com>
References: <mailman.1691.1368602017.3114.python-list@python.org>
	<51937A67.1000702@ncf.ca>
	<2ce10d3b-505b-4ba6-8fae-77facfaac654@hc4g2000pbb.googlegroups.com>
Message-ID: <sdde6a-uoq.ln1@satorlaser.homedns.org>

Am 16.05.2013 02:00, schrieb alex23:
> My favourite is this one:
> http://preshing.com/20110926/high-resolution-mandelbrot-in-obfuscated-python

Not only is this blog entry an interesting piece of art, there's other 
interesting things to read there, too.

Thanks!

Uli




From rosuav at gmail.com  Thu May 16 03:24:00 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 16 May 2013 17:24:00 +1000
Subject: Fractal
In-Reply-To: <sdde6a-uoq.ln1@satorlaser.homedns.org>
References: <mailman.1691.1368602017.3114.python-list@python.org>
	<51937A67.1000702@ncf.ca>
	<2ce10d3b-505b-4ba6-8fae-77facfaac654@hc4g2000pbb.googlegroups.com>
	<sdde6a-uoq.ln1@satorlaser.homedns.org>
Message-ID: <CAPTjJmo32WQsLgH3KMivE_eyFDVmMXaDDFb7s_N8YNd0-oJ9Fg@mail.gmail.com>

On Thu, May 16, 2013 at 5:11 PM, Ulrich Eckhardt
<ulrich.eckhardt at dominolaser.com> wrote:
> Am 16.05.2013 02:00, schrieb alex23:
>
>> My favourite is this one:
>>
>> http://preshing.com/20110926/high-resolution-mandelbrot-in-obfuscated-python
>
>
> Not only is this blog entry an interesting piece of art, there's other
> interesting things to read there, too.

I'm quite impressed, actually. Most people don't use Python for code
art. Significant indentation is not usually a good thing there :)

ChrisA


From invalid at invalid.invalid  Wed May 15 10:24:18 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 15 May 2013 14:24:18 +0000 (UTC)
Subject: Fractal
References: <mailman.1691.1368602017.3114.python-list@python.org>
Message-ID: <kn05qi$jtu$1@reader1.panix.com>

On 2013-05-13, Sharon COUKA <sharon_couka at hotmail.com> wrote:

> Hello, I'm new to python and i have to make a Mandelbrot fractal image for school but I don't know how to zoom in my image.
> Thank you for helping me.

It's a fractal image, so you zoom in/out with the following Python
instruction:

   pass

;)

-- 
Grant Edwards               grant.b.edwards        Yow! I'm not available
                                  at               for comment..
                              gmail.com            


From ian.g.kelly at gmail.com  Wed May 15 11:20:24 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 15 May 2013 09:20:24 -0600
Subject: Fractal
In-Reply-To: <DUB406-EAS2733F3138D2284E49821C21EAA00@phx.gbl>
References: <DUB406-EAS2733F3138D2284E49821C21EAA00@phx.gbl>
Message-ID: <CALwzidmj9_tud-mdTv0CYKC+rhev0GgSwsi4cZhKZRFWwGRfYA@mail.gmail.com>

On Mon, May 13, 2013 at 9:41 AM, Sharon COUKA <sharon_couka at hotmail.com> wrote:
> Hello, I'm new to python and i have to make a Mandelbrot fractal image for school but I don't know how to zoom in my image.
> Thank you for helping me.

Is this a GUI application or does it just write the image to a file?
What GUI / image library are you using?


From ian.g.kelly at gmail.com  Thu May 16 11:35:43 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 16 May 2013 09:35:43 -0600
Subject: Fractal
In-Reply-To: <DUB403-EAS298981D0889EB4B31B2278CEAA30@phx.gbl>
References: <DUB406-EAS2733F3138D2284E49821C21EAA00@phx.gbl>
	<CALwzidmj9_tud-mdTv0CYKC+rhev0GgSwsi4cZhKZRFWwGRfYA@mail.gmail.com>
	<DUB403-EAS298981D0889EB4B31B2278CEAA30@phx.gbl>
Message-ID: <CALwzidmkXcr-5=h_AZu-7S3ZEStu0Gb5CzoXYmVBirzwZ2Y2QA@mail.gmail.com>

On Thu, May 16, 2013 at 5:04 AM, Sharon COUKA <sharon_couka at hotmail.com> wrote:
> I have to write the script, and i have one but the zoom does not work

That doesn't answer my question.  Perhaps if you would share with us
what you already have, then we could point out what you need to do and
where to get your "zoom" working.


From ian.g.kelly at gmail.com  Thu May 16 13:53:47 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 16 May 2013 11:53:47 -0600
Subject: Fractal
In-Reply-To: <DUB101-W288C9AB231A14B2A196F57EAA30@phx.gbl>
References: <DUB406-EAS2733F3138D2284E49821C21EAA00@phx.gbl>
	<CALwzidmj9_tud-mdTv0CYKC+rhev0GgSwsi4cZhKZRFWwGRfYA@mail.gmail.com>
	<DUB403-EAS298981D0889EB4B31B2278CEAA30@phx.gbl>
	<CALwzidmkXcr-5=h_AZu-7S3ZEStu0Gb5CzoXYmVBirzwZ2Y2QA@mail.gmail.com>
	<DUB101-W288C9AB231A14B2A196F57EAA30@phx.gbl>
Message-ID: <CALwzidmaYg=kFarEK8W1e2cX_6bwje+0s1Oqea5B-zqO=HENOw@mail.gmail.com>

On Thu, May 16, 2013 at 10:55 AM, Sharon COUKA <sharon_couka at hotmail.com> wrote:
> # Register events
> c.bind('i', zoom)
> c.bind('i', unzoom)
> c.bind('i', mouseMove)

I'm not an expert at Tkinter so maybe one of the other residents can
help you better with that.  The code above looks wrong to me, though.
As far as I know, 'i' is not a valid event sequence in Tkinter, and
besides you probably want to bind these functions to three *different*
events.  See here for the docs on event sequences:

http://infohost.nmt.edu/tcc/help/pubs/tkinter/web/event-sequences.html

Based on your code, it looks like you would probably want something like:

c.bind('<Button-1>', zoom)
c.bind('<Button-2>', unzoom)
c.bind('<Motion>', mouseMove)


From jonathan.hayward at pobox.com  Mon May 13 11:59:33 2013
From: jonathan.hayward at pobox.com (Jonathan Hayward)
Date: Mon, 13 May 2013 10:59:33 -0500
Subject: Getting ASCII encoding where unicode wanted under Py3k
Message-ID: <CAE6_B5TDWrv4riQ27xQ+ENQHV=0ziryagsaXMRgNfwQGxmfDAA@mail.gmail.com>

I have a Py3k script, pasted below. When I run it I get an error about
ASCII codecs that can't handle byte values that are too high.

The error that I am getting is:

UnicodeEncodeError: 'ascii' codec can't encode character '\u0161' in
position 1442: ordinal not in range(128)
      args = ('ascii', "Content-Type: text/html\n\n<!DOCTYPE
html>\n<html>\n...ype='submit'>\n </form>\n </body>\n</html>", 1442,
1443, 'ordinal not in range(128)')
      encoding = 'ascii'
      end = 1443
      object = "Content-Type: text/html\n\n<!DOCTYPE
html>\n<html>\n...ype='submit'>\n </form>\n </body>\n</html>"
      reason = 'ordinal not in range(128)'
      start = 1442
      with_traceback = <built-in method with_traceback of
UnicodeEncodeError object>

(And that was posted to StackOverflow--one shot in the dark answer so far.)

My code is below. What should I be doing differently to be, in the most
immediate sense, calls to '''%(foo)s''' % locals()?

#!/usr/bin/python3

import cgi
import cgitb;cgitb.enable()
import os
import pickle
import sys

cgi_form = cgi.FieldStorage()

message = ''

def get_cgi(field, default = ""):
    return cgi_form.getfirst(field, default)

try:
    sys.stderr.write('abc: 1')
    input_file = open(
      os.path.join(os.path.dirname(__file__), '../../../russian/pickled'), 'rb')
    sys.stderr.write('abc: 2')
    state = pickle.load(input_file)
    sys.stderr.write('abc: 3')
    state['changed'] = False
    sys.stderr.write('abc: 4')
    state['loaded'] = True
    sys.stderr.write('abc: 5')
except IOError:
    state = {}
    state['phrases'] = []
    state['changed'] = True
    state['loaded'] = False
#except UnicodeDecodeError:
    #state = {}
    #state['phrases'] = []
    #state['changed'] = True
    state['loaded'] = False

if get_cgi('russian') and get_cgi('english'):
    state['phrases'].append([get_cgi('russian'), get_cgi('english')])
    message = 'Your changes have been saved.'
    state['changed'] = True
elif get_cgi('english'):
    state['phrases'].append([None, get_cgi('english')])
    message = 'Your change has been saved.'
    state['changed'] = True

if get_cgi('mode') == 'edit':
    to_delete = []
    for index in range(len(state['phrases'])):
        if get_cgi('russian_' + str(index), None) != None:
            state['phrases'][index][0] = get_cgi('russian_' + str(index))
        if get_cgi('english_' + str(index), None) != None:
            state['phrases'][index][1] = get_cgi('english_' + str(index))
        if get_cgi('delete_' + str(index), None) != None:
            to_delete.insert(0, index)
            #to_delete.append(index)
    #to_delete.sort(lambda a, b: -cmp(a, b))
    for element in to_delete:
        del state['phrases'][element]
    state['changed'] = True

sys.stderr.write('abc: ' + repr(state))

if state['changed']:
    output_file = open(
      os.path.join(os.path.dirname(__file__), '../../../russian/pickled_new.' +
        str(os.getpid())), 'wb')
    pickle.dump(state, output_file)
    output_file.close()
    os.rename(
      os.path.join(os.path.dirname(__file__), '../../../russian/pickled_new.' +
        str(os.getpid())),
      os.path.join(os.path.dirname(__file__), '../../../russian/pickled'))

if get_cgi('mode') == 'add':
    print('''Content-type: text/html

<!DOCTYPE html>
<html>
    <head>
        <meta charset='UTF-8' />
        <style type="text/css">
            body
                {
                font-family: Verdana, Arial, sans;
                }
            input[type=text]
                {
                width: 100%%;
                }
            div.message
                {
                background-color: silver;
                }
        </style>
    </head>
    <body>
        <div class='message'>
            %(message)s
        </div>
        <form action='' method='POST'>
            <p><strong>Russian:</strong><br />
            <input type='text' id='russian' name='russian'></p>

            <p><strong>English:</strong><br />
            <input type='text' id='english' name='english'></p>

            <p><input type='submit'>
        </form>
        <script src='/include/jquery.js'></script>
        <script>
            jQuery('#Russian').focus();
        </script>
    </body>
</html>''' % locals())
elif get_cgi('mode') == 'edit':
    edit_table = '<table>'
    edit_table += '<thead>'
    edit_table += '<th>Russian</th>'
    edit_table += '<th>English</th>'
    edit_table += '<th>Delete</th>'
    edit_table += '</thead>'
    edit_table += '<tbody>'
    for index in range(len(state['phrases'])):
        if state['phrases'][index][0]:
            russian = state['phrases'][index][0].replace('"', "''")
        else:
            russian = None
        english = state['phrases'][index][1].replace('"', "''")
        edit_table += '<tr>'
        edit_table += '<td>'
        if russian != None:
            edit_table += '''<input type='text' name='russian_%(index)d'
            id='russian_%(index)d' value="%(russian)s">''' % locals()
        edit_table += '</td>\n'
        edit_table += '<td>'
        edit_table += '''<input type='text' name='english_%(index)d'
        id='english_%(index)d' value="%(english)s">''' % locals()
        edit_table += '<td>'
        edit_table += '''<input type='checkbox' name='delete_%(index)d'
        id='delete_%(index)d'>''' % locals()
        edit_table += '</td>\n'
        edit_table += '</tr>'
    print ('''Content-Type: text/html

<!DOCTYPE html>
<html>
    <head>
        <title>Edit Phrases</title>
        <meta charset='utf-8' />
    </head>
    <body>
        <form action='' name='edit' id='edit' />
            <input type='hidden' name='mode' value='edit' />
            %(edit_table)s
            <input type='submit'>
        </form>
    </body>
</html>''' % locals())
else:
    text = ''
    for phrase in state['phrases']:
        if phrase[0]:
            text += ('<p title="' + phrase[1].replace('"', "''") + '">' +
              phrase[0] + '</p>')
        else:
            text += '<h2>' + phrase[1] + '</h2>'

    print ('''Content-type: text/html

<!DOCTYPE html>
<html>
    <head>
        <title>___________</title>
        <meta charset='utf-8'>
        <style type='text/css'>
            body
                {
                font-family: Verdana, Arial, sans;
                }
            div
                {
                background-color: #ffff00;
                }
        </style>
        <link rel='stylesheet' type='text/css'
        href='/js/jquery-ui-1.10.2.custom/css/smoothness/jquery-ui-1.10.2.custom.css'
        />
    </head>
    <body>
        %(text)s
        <script src='/js/vendor/jquery-1.8.2-min.js'></script>
        <script
        src='/js/jquery-ui-1.10.2.custom/js/jquery-ui-1.10.2.custom.min.js'></script>
        <script>
            jQuery(document).tooltip();
        </script>
    </body>
</html>''' % locals())


-- 
[image: Christos Jonathan Hayward] <http://jonathanscorner.com/>
Christos Jonathan Hayward, an Orthodox Christian author.

*Amazon <http://amazon.com/author/cjshayward>* ? Author
Bio<http://jonathanscorner.com/author/>
 ? *Author Site <http://cjsh.name/>* ?
*Email<christos.jonathan.hayward at gmail.com>
* ? Facebook <http://www.facebook.com/christos.jonathan.hayward> ? Fan
Page<http://fan.cjshayward.com/>
 ? Google Plus <http://jonathanscorner.com/plus> ?
LinkedIn<http://www.linkedin.com/in/jonathanhayward>
 ? *Professional <http://jonathanhayward.com/>* ?
Twitter<http://twitter.com/JonathansCorner>
 ? *Web <http://jonathanscorner.com/>* ? What's
New?<http://jonathanscorner.com/>
If you read just *one* of my books, you'll want *The Best of Jonathan's
Corner <http://www.amazon.com/dp/1478219912>*.
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From python at mrabarnett.plus.com  Mon May 13 12:34:15 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 13 May 2013 17:34:15 +0100
Subject: Getting ASCII encoding where unicode wanted under Py3k
In-Reply-To: <CAE6_B5TDWrv4riQ27xQ+ENQHV=0ziryagsaXMRgNfwQGxmfDAA@mail.gmail.com>
References: <CAE6_B5TDWrv4riQ27xQ+ENQHV=0ziryagsaXMRgNfwQGxmfDAA@mail.gmail.com>
Message-ID: <51911607.9010609@mrabarnett.plus.com>

On 13/05/2013 16:59, Jonathan Hayward wrote:
> I have a Py3k script, pasted below. When I run it I get an error about
> ASCII codecs that can't handle byte values that are too high.
>
> The error that I am getting is:
>
> |UnicodeEncodeError:  'ascii'  codec can't encode character'\u0161' in position 1442: ordinal not in range(128)
>        args = ('ascii', "Content-Type: text/html\n\n<!DOCTYPE html>\n<html>\n...ype='submit'>\n </form>\n </body>\n</html>", 1442, 1443,'ordinalnot  in  range(128)')
>        encoding = 'ascii'
>        end = 1443
>        object = "Content-Type: text/html\n\n<!DOCTYPE html>\n<html>\n...ype='submit'>\n </form>\n </body>\n</html>"
>        reason = 'ordinalnot  in  range(128)'
>        start = 1442
>        with_traceback = <built-in method with_traceback of UnicodeEncodeError object>|
>
> (And that was posted to StackOverflow--one shot in the dark answer so far.)
>
> My code is below. What should I be doing differently to be, in the most
> immediate sense, calls to '''%(foo)s''' % locals()?
>
[snip]
The 'print' functions send its output to sys.stdout, which, in your
case, is set up to encode to ASCII for output, but '\u0161' can't be
encoded to ASCII.

Try encoding to UTF-8 instead:

from codecs import getwriter

sys.stdout = getwriter("utf-8")(sys.stdout.buffer)



From ppearson at nowhere.invalid  Mon May 13 12:32:57 2013
From: ppearson at nowhere.invalid (Peter Pearson)
Date: 13 May 2013 16:32:57 GMT
Subject: Getting ASCII encoding where unicode wanted under Py3k
References: <mailman.1629.1368460785.3114.python-list@python.org>
Message-ID: <avcitpF9jacU1@mid.individual.net>

On Mon, 13 May 2013 10:59:33 -0500, Jonathan Hayward wrote:
> --e89a8f3b9db145cbab04dc9b9a23
> Content-Type: text/plain; charset=windows-1252
> Content-Transfer-Encoding: quoted-printable
>

[snipped many lines of quoted-printable muck]

> My code is below. What should I be doing differently to be, in the most
> immediate sense, calls to '''%(foo)s''' % locals()?

[snipped about 200 lines of code, presented in quoted-printable]

You will greatly increase your odds of getting a useful response
if you post the shortest possible program that exhibits your
problem.  Posting it as plain text would help, too.

-- 
To email me, substitute nowhere->spamcop, invalid->net.


From carl at personnelware.com  Mon May 13 13:01:17 2013
From: carl at personnelware.com (Carl Karsten)
Date: Mon, 13 May 2013 12:01:17 -0500
Subject: [Chicago] Getting ASCII encoding where unicode wanted under Py3k
In-Reply-To: <CAE6_B5TDWrv4riQ27xQ+ENQHV=0ziryagsaXMRgNfwQGxmfDAA@mail.gmail.com>
References: <CAE6_B5TDWrv4riQ27xQ+ENQHV=0ziryagsaXMRgNfwQGxmfDAA@mail.gmail.com>
Message-ID: <CADmzSSiY-UqXOdpzUZt9K-MJ=oUhmFyVgdxxapVciwp9DBQNYQ@mail.gmail.com>

On Mon, May 13, 2013 at 10:59 AM, Jonathan Hayward
<jonathan.hayward at pobox.com> wrote:

That is way too much code for me to try and dig into.

Remove everything not needed to demo it.  Replace big strings with
little strings.

My guess is it should be 1-3 lines, like

>>> print('123%(a)s' % {'a': u'\u0161' } )
123?

But that works.  may need a few other lines, or something.
It is also possible that there is a setting in your OS that has an effect.

What OS?

--
Carl K


From fabiosantosart at gmail.com  Mon May 13 17:44:04 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 13 May 2013 22:44:04 +0100
Subject: Writing a blog post on the new Enum.
Message-ID: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>

I have followed the process of the new PEP closely, and as such I know
that there is a repository containing the reference implementation, a
link to which was posted on the python-dev list. Is it okay to link to
this repository in my new blog post about the Enum, so my readers can
try it out? I will warn my readers about it not being final and not to
use in production code.

I am unsure whether the repository is not supposed to be shared with
too many people.

--
F?bio Santos


From breamoreboy at yahoo.co.uk  Mon May 13 18:56:55 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 13 May 2013 23:56:55 +0100
Subject: Writing a blog post on the new Enum.
In-Reply-To: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>
References: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>
Message-ID: <kmrr3l$ma$1@ger.gmane.org>

On 13/05/2013 22:44, F?bio Santos wrote:
> I have followed the process of the new PEP closely, and as such I know
> that there is a repository containing the reference implementation, a
> link to which was posted on the python-dev list. Is it okay to link to
> this repository in my new blog post about the Enum, so my readers can
> try it out? I will warn my readers about it not being final and not to
> use in production code.
>
> I am unsure whether the repository is not supposed to be shared with
> too many people.
>
> --
> F?bio Santos
>

My understanding is that nobody can mention this on pain of being 
subject to the Comfy Chair.  I hope this clarifies everything.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From ethan at stoneleaf.us  Mon May 13 19:09:55 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 13 May 2013 16:09:55 -0700
Subject: Writing a blog post on the new Enum.
In-Reply-To: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>
References: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>
Message-ID: <519172C3.4030108@stoneleaf.us>

On 05/13/2013 02:44 PM, F?bio Santos wrote:
> I have followed the process of the new PEP closely, and as such I know
> that there is a repository containing the reference implementation, a
> link to which was posted on the python-dev list. Is it okay to link to
> this repository in my new blog post about the Enum, so my readers can
> try it out? I will warn my readers about it not being final and not to
> use in production code.
>
> I am unsure whether the repository is not supposed to be shared with
> too many people.

I just checked my settings there, and it looks like you're okay since the folks reading your blog would just be 
downloading, not logging and directly manipulating the repository.

--
~Ethan~


From fabiosantosart at gmail.com  Mon May 13 19:40:38 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 14 May 2013 00:40:38 +0100
Subject: Writing a blog post on the new Enum.
In-Reply-To: <519172C3.4030108@stoneleaf.us>
References: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>
	<519172C3.4030108@stoneleaf.us>
Message-ID: <CAA=1kxSHKjoTYZZ7Gs_Tpo+h3hRVQRb0p8aeEnnKuXf9jWA4cA@mail.gmail.com>

On Tue, May 14, 2013 at 12:09 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
> I just checked my settings there, and it looks like you're okay since the
> folks reading your blog would just be downloading, not logging and directly
> manipulating the repository.
>
> --
> ~Ethan~


Okay, so I'm good. I'll go ahead and publish it.


On Mon, May 13, 2013 at 11:56 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> My understanding is that nobody can mention this on pain of being subject to
> the Comfy Chair.  I hope this clarifies everything.

Well I am thus defying the law and order of this world by publishing
it on the internets!

---

And here it is:
http://fabiosantoscode.blogspot.pt/2013/05/pythons-new-enum-class.html

--
F?bio Santos


From rosuav at gmail.com  Tue May 14 03:52:43 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 14 May 2013 17:52:43 +1000
Subject: Writing a blog post on the new Enum.
In-Reply-To: <CAA=1kxSHKjoTYZZ7Gs_Tpo+h3hRVQRb0p8aeEnnKuXf9jWA4cA@mail.gmail.com>
References: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>
	<519172C3.4030108@stoneleaf.us>
	<CAA=1kxSHKjoTYZZ7Gs_Tpo+h3hRVQRb0p8aeEnnKuXf9jWA4cA@mail.gmail.com>
Message-ID: <CAPTjJmpK2yRbDxy5SZQXvRi3dH0UGSmihNU4NJcpu_DY7A=+1g@mail.gmail.com>

On Tue, May 14, 2013 at 9:40 AM, F?bio Santos <fabiosantosart at gmail.com> wrote:
> Well I am thus defying the law and order of this world by publishing
> it on the internets!
>
> ---
>
> And here it is:
> http://fabiosantoscode.blogspot.pt/2013/05/pythons-new-enum-class.html

    class Text(unicode, Enum):
        one = u'one'
        two = u'two'
        three = u'three'

That looks like Python 2 code. Are you backporting Enum to Py2
manually? AIUI the Python core won't be adding features like that to
2.7, and there won't be a 2.8, so PEP 435 will be Py3.4+ only. Or have
I misunderstood it?

ChrisA


From tjreedy at udel.edu  Tue May 14 11:07:58 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Tue, 14 May 2013 11:07:58 -0400
Subject: Writing a blog post on the new Enum.
In-Reply-To: <CAPTjJmpK2yRbDxy5SZQXvRi3dH0UGSmihNU4NJcpu_DY7A=+1g@mail.gmail.com>
References: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>
	<519172C3.4030108@stoneleaf.us>
	<CAA=1kxSHKjoTYZZ7Gs_Tpo+h3hRVQRb0p8aeEnnKuXf9jWA4cA@mail.gmail.com>
	<CAPTjJmpK2yRbDxy5SZQXvRi3dH0UGSmihNU4NJcpu_DY7A=+1g@mail.gmail.com>
Message-ID: <kmtjvu$kb9$1@ger.gmane.org>

On 5/14/2013 3:52 AM, Chris Angelico wrote:
> On Tue, May 14, 2013 at 9:40 AM, F?bio Santos <fabiosantosart at gmail.com> wrote:

>> http://fabiosantoscode.blogspot.pt/2013/05/pythons-new-enum-class.html
>
>      class Text(unicode, Enum):
>          one = u'one'
>          two = u'two'
>          three = u'three'

Is this supposed to be a quote? or your rewrite? or did Santos rewrite 
after you posted? The blog currently has a 3.x version of that.

> That looks like Python 2 code. Are you backporting Enum to Py2
> manually? AIUI the Python core won't be adding features like that to
> 2.7, and there won't be a 2.8, so PEP 435 will be Py3.4+ only. Or have
> I misunderstood it?

As far as official CPython goes, Enum is 3.4+ only. I believe the module 
will continue to work on earlier 3.x and will remain externally 
available as a 3rd party module. Ethan said he plans to backport to 2.7 
so 2 & 3 code can use enums.




From rosuav at gmail.com  Tue May 14 11:36:32 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 15 May 2013 01:36:32 +1000
Subject: Writing a blog post on the new Enum.
In-Reply-To: <kmtjvu$kb9$1@ger.gmane.org>
References: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>
	<519172C3.4030108@stoneleaf.us>
	<CAA=1kxSHKjoTYZZ7Gs_Tpo+h3hRVQRb0p8aeEnnKuXf9jWA4cA@mail.gmail.com>
	<CAPTjJmpK2yRbDxy5SZQXvRi3dH0UGSmihNU4NJcpu_DY7A=+1g@mail.gmail.com>
	<kmtjvu$kb9$1@ger.gmane.org>
Message-ID: <CAPTjJmoHYi3QPo5gO+NDiNJ7VMc57epGkoOYgOAvnN14bRE8FA@mail.gmail.com>

On Wed, May 15, 2013 at 1:07 AM, Terry Jan Reedy <tjreedy at udel.edu> wrote:
> On 5/14/2013 3:52 AM, Chris Angelico wrote:
>>
>> On Tue, May 14, 2013 at 9:40 AM, F?bio Santos <fabiosantosart at gmail.com>
>> wrote:
>
>>> http://fabiosantoscode.blogspot.pt/2013/05/pythons-new-enum-class.html
>>
>>
>>      class Text(unicode, Enum):
>>          one = u'one'
>>          two = u'two'
>>          three = u'three'
>
>
> Is this supposed to be a quote? or your rewrite? or did Santos rewrite after
> you posted? The blog currently has a 3.x version of that.

It was a quote from the blog post as it had been when I posted it.
Presumably he edited the post subsequently, as I'm now seeing the same
thing you are, a 3.x-compat version. (The u'xx' prefixes wouldn't be a
problem, incidentally, so this could be dual-versionned just by going
"unicode = str".)

ChrisA


From fabiosantosart at gmail.com  Tue May 14 13:09:08 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 14 May 2013 18:09:08 +0100
Subject: Writing a blog post on the new Enum.
In-Reply-To: <CAPTjJmoHYi3QPo5gO+NDiNJ7VMc57epGkoOYgOAvnN14bRE8FA@mail.gmail.com>
References: <CAA=1kxQxcGpDzR6VDEb1urjjn4bnRvi4aoXKKa5+vgG186hzOg@mail.gmail.com>
	<519172C3.4030108@stoneleaf.us>
	<CAA=1kxSHKjoTYZZ7Gs_Tpo+h3hRVQRb0p8aeEnnKuXf9jWA4cA@mail.gmail.com>
	<CAPTjJmpK2yRbDxy5SZQXvRi3dH0UGSmihNU4NJcpu_DY7A=+1g@mail.gmail.com>
	<kmtjvu$kb9$1@ger.gmane.org>
	<CAPTjJmoHYi3QPo5gO+NDiNJ7VMc57epGkoOYgOAvnN14bRE8FA@mail.gmail.com>
Message-ID: <CAA=1kxSV3qf3-EpbB2Xi-e=2niv3cvCzwqrz9k=wsUsOzbPebA@mail.gmail.com>

I corrected it indeed.

On Tue, May 14, 2013 at 4:36 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Wed, May 15, 2013 at 1:07 AM, Terry Jan Reedy <tjreedy at udel.edu> wrote:
>> On 5/14/2013 3:52 AM, Chris Angelico wrote:
>>>
>>> On Tue, May 14, 2013 at 9:40 AM, F?bio Santos <fabiosantosart at gmail.com>
>>> wrote:
>>
>>>> http://fabiosantoscode.blogspot.pt/2013/05/pythons-new-enum-class.html
>>>
>>>
>>>      class Text(unicode, Enum):
>>>          one = u'one'
>>>          two = u'two'
>>>          three = u'three'
>>
>>
>> Is this supposed to be a quote? or your rewrite? or did Santos rewrite after
>> you posted? The blog currently has a 3.x version of that.
>
> It was a quote from the blog post as it had been when I posted it.
> Presumably he edited the post subsequently, as I'm now seeing the same
> thing you are, a 3.x-compat version. (The u'xx' prefixes wouldn't be a
> problem, incidentally, so this could be dual-versionned just by going
> "unicode = str".)
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list



-- 
F?bio Santos


From alok.jadhav at credit-suisse.com  Tue May 14 02:54:25 2013
From: alok.jadhav at credit-suisse.com (Jadhav, Alok)
Date: Tue, 14 May 2013 14:54:25 +0800
Subject: weave and 64 bit issues
Message-ID: <CEE8C35195DB944D9C75ABB15A04193B21E9AF90@EHKG17P32001A.csfb.cs-group.com>

Hi everyone,

 

I am facing a strange problem using weave on 64 bit machine.
Specifically with weave's inline function. It has something to do with
weave's catalog. 

 

Similar issues I found in the past (very old)

 

http://mail.scipy.org/pipermail/scipy-dev/2006-June/005908.html

http://mail.scipy.org/pipermail/scipy-dev/2005-June/003042.html

 

 

I have a simple script to calculate moving average using weave's inline
function. 

 

 

 

File mvg.py

 

import numpy as np

import scipy.weave as weave

import distutils.sysconfig

import distutils.dir_util

import os

 

distutils.sysconfig._config_vars["LDSHARED"]="-LC:\strawberry64\c\x86_64
-w64-mingw32\lib"

 

 

def ExpMovAvg(data,time,lag):

    if (data.size!=time.size):

        print "error in EMA, data and time have different size"

        return None

    result=np.repeat(0.0,data.size)

    code="""

    #line 66 "basics.py"

    result(0)=data(0);

    for (int i=0;i<data.size()-1;i++)

    {

        //double alpha=1-(2.0/(lag+1)*(time(i)-time(i-1)));

        double dt=time(i+1)-time(i);

        double alpha=pow(0.13533, dt / lag);

        if(alpha>1)

        {

            alpha=10;

        }

        result(i+1)=(1-alpha)*data(i)+alpha*result(i);

    }

    """

 
weave.inline(code,["data","time","lag","result"],type_converters=weave.c
onverters.blitz,headers=["<math.h>"],compiler="gcc",verbose=2)

    return result

 

 

file test.py

 

import string

import numpy as np

import mvg

 

print(mvg.ExpMovAvg(np.array(range(10)),np.array(range(10)),2))

 

 

 

Output:

 

 

Working output:

 

Y:\STMM\alpha\klse\PROD>c:\python27\python.exe
s:\common\tools\python\python-2.7-64bit\test.py

[ 0.          0.          0.63212774  1.49679774  2.44701359  3.42869938
4.42196209  5.41948363  6.41857187  7.41823646]

 

Now if I keep running the script multiple times, sometimes I see correct
output... but suddenly sometimes I get below error.

 

Y:\STMM\alpha\klse\PROD>c:\python27\python.exe
s:\common\tools\python\python-2.7-64bit\test.py

repairing catalog by removing key

<weave: compiling>

Looking for python27.dll

running build_ext

running build_src

build_src

building extension "sc_44f3fe3c65d5c3feecb45d9269ac207f5" sources

build_src: building npy-pkg config files

Looking for python27.dll

customize Mingw32CCompiler

customize Mingw32CCompiler using build_ext

Looking for python27.dll

customize Mingw32CCompiler

customize Mingw32CCompiler using build_ext

building 'sc_44f3fe3c65d5c3feecb45d9269ac207f5' extension

compiling C++ sources

C compiler: g++ -g -DDEBUG -DMS_WIN64 -O0 -Wall

 

compile options: '-Ic:\python27\lib\site-packages\scipy\weave
-Ic:\python27\lib\site-packages\scipy\weave\scxx
-Ic:\python27\lib\site-packages\scipy\weave\blitz

-Ic:\python27\lib\site-packages\numpy\core\include -Ic:\python27\include
-Ic:\python27\PC -c' 

 g++ -g -DDEBUG -DMS_WIN64 -O0 -Wall
-Ic:\python27\lib\site-packages\scipy\weave

-Ic:\python27\lib\site-packages\scipy\weave\scxx
-Ic:\python27\lib\site-packages\scipy\weave\blitz
-Ic:\python27\lib\site-packages\numpy\core\include -Ic:\pytho

n27\include -Ic:\python27\PC -c
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_compiled\sc_44f3f
e3c65d5c3feecb45d9269ac207f5.cpp -o c:\users\ajadhav2\ap

pdata\local\temp\ajadhav2\python27_intermediate\compiler_2d3e1e2e4de6a91
419d2376b162e5342\Release\users\ajadhav2\appdata\local\temp\ajadhav2\pyt
hon27_compiled\s

c_44f3fe3c65d5c3feecb45d9269ac207f5.o

Found executable C:\strawberry\c\bin\g++.exe

g++ -g -DDEBUG -DMS_WIN64 -O0 -Wall
-Ic:\python27\lib\site-packages\scipy\weave-Ic:\python27\lib\site-packag
es\scipy\weave\scxx -Ic:\python27\lib\site-packages

\scipy\weave\blitz -Ic:\python27\lib\site-packages\numpy\core\include
-Ic:\python27\include -Ic:\python27\PC -c
c:\python27\lib\site-packages\scipy\weave\scxx\w

eave_imp.cpp -o
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_intermediate\comp
iler_2d3e1e2e4de6a91419d2376b162e5342\Release\python27\lib\site-packages

\scipy\weave\scxx\weave_imp.o

g++ -g -shared
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_intermediate\comp
iler_2d3e1e2e4de6a91419d2376b162e5342\Release\users\ajadhav2\appdata\loc
a

l\temp\ajadhav2\python27_compiled\sc_44f3fe3c65d5c3feecb45d9269ac207f5.o
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_intermediate\comp
iler_2d3e1e2e4d

e6a91419d2376b162e5342\Release\python27\lib\site-packages\scipy\weave\sc
xx\weave_imp.o -Lc:\python27\libs -Lc:\python27\PCbuild\amd64 -lpython27
-lmsvcr90 -o c:

\users\ajadhav2\appdata\local\temp\ajadhav2\python27_compiled\sc_44f3fe3
c65d5c3feecb45d9269ac207f5.pyd

running scons

Traceback (most recent call last):

  File "s:\common\tools\python\python-2.7-64bit\test.py", line 5, in
<module>

    print(mvg.ExpMovAvg(np.array(range(10)),np.array(range(10)),2))

  File "s:\common\tools\python\python-2.7-64bit\mvg.py", line 30, in
ExpMovAvg

 
weave.inline(code,["data","time","lag","result"],type_converters=weave.c
onve

rters.blitz,headers=["<math.h>"],compiler="gcc",verbose=2)

  File "c:\python27\lib\site-packages\scipy\weave\inline_tools.py", line
355, in

inline

    **kw)

  File "c:\python27\lib\site-packages\scipy\weave\inline_tools.py", line
488, in

compile_function

    exec 'import ' + module_name

  File "<string>", line 1, in <module>

ImportError: DLL load failed: Invalid access to memory location.

 

Y:\STMM\alpha\klse\PROD>

 

 

 

For everytime there is an error I have one observation, the message has
notification

 

"repairing catalog by removing key"  which leads to DLL load failed
error.

 

 

Any ideas?

 

-

Alok 

 

 

 


=============================================================================== 
Please access the attached hyperlink for an important electronic communications disclaimer: 
http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html 
=============================================================================== 

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From hossamalagmy at gmail.com  Tue May 14 08:34:03 2013
From: hossamalagmy at gmail.com (23alagmy)
Date: Tue, 14 May 2013 05:34:03 -0700 (PDT)
Subject: ssl proxy server
Message-ID: <0eb46c91-e290-458d-8be7-ded950bc1c6d@12g2000vba.googlegroups.com>

ssl proxy server

http://natigtas7ab.blogspot.com/2013/05/ssl-proxy-server.html


From kwpolska at gmail.com  Tue May 14 14:40:12 2013
From: kwpolska at gmail.com (=?UTF-8?B?Q2hyaXMg4oCcS3dwb2xza2HigJ0gV2Fycmljaw==?=)
Date: Tue, 14 May 2013 20:40:12 +0200
Subject: ssl proxy server
In-Reply-To: <0eb46c91-e290-458d-8be7-ded950bc1c6d@12g2000vba.googlegroups.com>
References: <0eb46c91-e290-458d-8be7-ded950bc1c6d@12g2000vba.googlegroups.com>
Message-ID: <CAMw+j7+Ak9Mj6PaZR+67LQcQvbezTQBb3xUzv2kWfD17nHHg8Q@mail.gmail.com>

On Tue, May 14, 2013 at 2:34 PM, 23alagmy <hossamalagmy at gmail.com> wrote:
> ssl proxy server
>
> hxxp://natigtas7ab.blogspot.com/2013/05/ssl-proxy-server.html
> --
> http://mail.python.org/mailman/listinfo/python-list

I have been seeing those mails for a long time.  Why didn?t anybody
ban that guy?  If it comes from Usenet (and headers say it does), and
you can?t destroy stuff easily there, maybe just put a ban on the
Mailman side of things, making the world much better for at least some
people?


From skip at pobox.com  Tue May 14 15:14:55 2013
From: skip at pobox.com (Skip Montanaro)
Date: Tue, 14 May 2013 14:14:55 -0500
Subject: ssl proxy server
In-Reply-To: <CAMw+j7+Ak9Mj6PaZR+67LQcQvbezTQBb3xUzv2kWfD17nHHg8Q@mail.gmail.com>
References: <0eb46c91-e290-458d-8be7-ded950bc1c6d@12g2000vba.googlegroups.com>
	<CAMw+j7+Ak9Mj6PaZR+67LQcQvbezTQBb3xUzv2kWfD17nHHg8Q@mail.gmail.com>
Message-ID: <CANc-5UxKXErEgzWXuBdpHC5Dd+fq94fOareuqZqoJzA_7QsxdA@mail.gmail.com>

I haven't touched the SpamBayes setup for the usenet-to-mail gateway
in a long while.  For whatever reason, this message was either held
and then approved by the current list moderator(s), or (more likely)
slipped through unscathed.  No filter is perfect.

Skip

On Tue, May 14, 2013 at 1:40 PM, Chris ?Kwpolska? Warrick
<kwpolska at gmail.com> wrote:
> On Tue, May 14, 2013 at 2:34 PM, 23alagmy <hossamalagmy at gmail.com> wrote:
>> ssl proxy server
>>
>> hxxp://natigtas7ab.blogspot.com/2013/05/ssl-proxy-server.html
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
> I have been seeing those mails for a long time.  Why didn?t anybody
> ban that guy?  If it comes from Usenet (and headers say it does), and
> you can?t destroy stuff easily there, maybe just put a ban on the
> Mailman side of things, making the world much better for at least some
> people?
> --
> http://mail.python.org/mailman/listinfo/python-list


From kwpolska at gmail.com  Wed May 15 14:58:15 2013
From: kwpolska at gmail.com (=?UTF-8?B?Q2hyaXMg4oCcS3dwb2xza2HigJ0gV2Fycmljaw==?=)
Date: Wed, 15 May 2013 20:58:15 +0200
Subject: ssl proxy server
In-Reply-To: <CANc-5UxKXErEgzWXuBdpHC5Dd+fq94fOareuqZqoJzA_7QsxdA@mail.gmail.com>
References: <0eb46c91-e290-458d-8be7-ded950bc1c6d@12g2000vba.googlegroups.com>
	<CAMw+j7+Ak9Mj6PaZR+67LQcQvbezTQBb3xUzv2kWfD17nHHg8Q@mail.gmail.com>
	<CANc-5UxKXErEgzWXuBdpHC5Dd+fq94fOareuqZqoJzA_7QsxdA@mail.gmail.com>
Message-ID: <CAMw+j7+Evu+FLuUNCR7ViDvHYd_5UXZtVgKmg5n5=3PS_1NV1w@mail.gmail.com>

On Tue, May 14, 2013 at 9:14 PM, Skip Montanaro <skip at pobox.com> wrote:
> I haven't touched the SpamBayes setup for the usenet-to-mail gateway
> in a long while.  For whatever reason, this message was either held
> and then approved by the current list moderator(s), or (more likely)
> slipped through unscathed.  No filter is perfect.
>
> Skip

A filter on this guy altogether would be.  He sent 24 messages there
since February 25.  All of them spam.

--
Kwpolska <http://kwpolska.tk> | GPG KEY: 5EAAEA16
stop html mail                | always bottom-post
http://asciiribbon.org        | http://caliburn.nl/topposting.html


From zachary.ware+pylist at gmail.com  Wed May 15 15:10:38 2013
From: zachary.ware+pylist at gmail.com (Zachary Ware)
Date: Wed, 15 May 2013 14:10:38 -0500
Subject: ssl proxy server
In-Reply-To: <CAMw+j7+Evu+FLuUNCR7ViDvHYd_5UXZtVgKmg5n5=3PS_1NV1w@mail.gmail.com>
References: <0eb46c91-e290-458d-8be7-ded950bc1c6d@12g2000vba.googlegroups.com>
	<CAMw+j7+Ak9Mj6PaZR+67LQcQvbezTQBb3xUzv2kWfD17nHHg8Q@mail.gmail.com>
	<CANc-5UxKXErEgzWXuBdpHC5Dd+fq94fOareuqZqoJzA_7QsxdA@mail.gmail.com>
	<CAMw+j7+Evu+FLuUNCR7ViDvHYd_5UXZtVgKmg5n5=3PS_1NV1w@mail.gmail.com>
Message-ID: <CAKJDb-OwAzXx_r=vrk8-EC=wps2+yD-v95Petf6Whob8sLxsOg@mail.gmail.com>

On Wed, May 15, 2013 at 1:58 PM, Chris ?Kwpolska? Warrick
<kwpolska at gmail.com> wrote:
> On Tue, May 14, 2013 at 9:14 PM, Skip Montanaro <skip at pobox.com> wrote:
>> I haven't touched the SpamBayes setup for the usenet-to-mail gateway
>> in a long while.  For whatever reason, this message was either held
>> and then approved by the current list moderator(s), or (more likely)
>> slipped through unscathed.  No filter is perfect.
>>
>> Skip
>
> A filter on this guy altogether would be.  He sent 24 messages there
> since February 25.  All of them spam.
>

You can always set your own filter.  I had been somewhat confused by
this thread until I realized the initial message had been killed by a
filter I set up a while back.


From commx at commx.ws  Tue May 14 11:05:53 2013
From: commx at commx.ws (Christian Jurk)
Date: Tue, 14 May 2013 08:05:53 -0700 (PDT)
Subject: PDF generator decision
Message-ID: <3f4500ad-784a-401d-a089-e2b7081821e9@googlegroups.com>

Hi folks,

This questions may be asked several times already, but the development of relevant software continues day-for-day. For some time now I've been using xhtml2pdf [1] to generate PDF documents from HTML templates (which are rendered through my Django-based web application. This have been working for some time now but I'm constantly adding new templates and they are not looking like I want it (sometimes bold text is bold, sometimes not, layout issues, etc). I'd like to use something else than xhtml2pdf.

So far I'd like to ask which is the (probably) best way to create PDFs in Python (3)? It is important for me that I am able to specify not only background graphics, paragaphs, tables and so on but also to specify page headers/footers. The reason is that I have a bunch of documents to be generated (including Invoice templates, Quotes - stuff like that).

Any advice is welcome. Thanks.

[1] https://github.com/chrisglass/xhtml2pdf


From fpm at u.washington.edu  Tue May 14 11:21:36 2013
From: fpm at u.washington.edu (Frank Miles)
Date: Tue, 14 May 2013 15:21:36 +0000 (UTC)
Subject: PDF generator decision
References: <3f4500ad-784a-401d-a089-e2b7081821e9@googlegroups.com>
Message-ID: <kmtkq0$sdo$1@dont-email.me>

On Tue, 14 May 2013 08:05:53 -0700, Christian Jurk wrote:

> Hi folks,
> 
> This questions may be asked several times already, but the development
> of relevant software continues day-for-day. For some time now I've been
> using xhtml2pdf [1] to generate PDF documents from HTML templates (which
> are rendered through my Django-based web application. This have been
> working for some time now but I'm constantly adding new templates and
> they are not looking like I want it (sometimes bold text is bold,
> sometimes not, layout issues, etc). I'd like to use something else than
> xhtml2pdf.
> 
> So far I'd like to ask which is the (probably) best way to create PDFs
> in Python (3)? It is important for me that I am able to specify not only
> background graphics, paragaphs, tables and so on but also to specify
> page headers/footers. The reason is that I have a bunch of documents to
> be generated (including Invoice templates, Quotes - stuff like that).
> 
> Any advice is welcome. Thanks.
> 
> [1] https://github.com/chrisglass/xhtml2pdf

Reportlab works well in Python 2.x.  Their _next_ version is supposed to 
work with Python3... {yes, not much help there}


From wxjmfauth at gmail.com  Tue May 14 13:36:52 2013
From: wxjmfauth at gmail.com (jmfauth)
Date: Tue, 14 May 2013 10:36:52 -0700 (PDT)
Subject: PDF generator decision
References: <3f4500ad-784a-401d-a089-e2b7081821e9@googlegroups.com>
Message-ID: <39026458-6d08-49ec-8e35-802e17dae7dd@o10g2000vbp.googlegroups.com>

On 14 mai, 17:05, Christian Jurk <co... at commx.ws> wrote:
> Hi folks,
>
> This questions may be asked several times already, but the development of relevant software continues day-for-day. For some time now I've been using xhtml2pdf [1] to generate PDF documents from HTML templates (which are rendered through my Django-based web application. This have been working for some time now but I'm constantly adding new templates and they are not looking like I want it (sometimes bold text is bold, sometimes not, layout issues, etc). I'd like to use something else than xhtml2pdf.
>
> So far I'd like to ask which is the (probably) best way to create PDFs in Python (3)? It is important for me that I am able to specify not only background graphics, paragaphs, tables and so on but also to specify page headers/footers. The reason is that I have a bunch of documents to be generated (including Invoice templates, Quotes - stuff like that).
>
> Any advice is welcome. Thanks.
>
> [1]https://github.com/chrisglass/xhtml2pdf

-----

1) Use Python to collect your data (db, pictures, texts, ...)
and/or to create the material (text, graphics, ...) that will
be the contents (source) of your your pdf's.
2) Put this source in .tex file (a plain text file).
3) Let it compile with a TeX engine.

- I can not figure out something more versatile and basically
simple (writing a text file).
- Do not forget you are the only one who knows the content
and the layout of your document(s).

jmf


From dieter at handshake.de  Wed May 15 02:22:25 2013
From: dieter at handshake.de (dieter)
Date: Wed, 15 May 2013 08:22:25 +0200
Subject: PDF generator decision
References: <3f4500ad-784a-401d-a089-e2b7081821e9@googlegroups.com>
Message-ID: <877gj0vk2m.fsf@handshake.de>

Christian Jurk <commx at commx.ws> writes:

> ...
> So far I'd like to ask which is the (probably) best way to create PDFs in Python (3)? It is important for me that I am able to specify not only background graphics, paragaphs, tables and so on but also to specify page headers/footers. The reason is that I have a bunch of documents to be generated (including Invoice templates, Quotes - stuff like that).

High quality layouts, especially those containing (potentially complex
tables), are very difficult to generate automatically.

I do not suppose that you will find a generic solution - one applicable
to a wide range of document classes and garanteeing high quality
layout for almost all of its document instances.



From carlosnepomuceno at outlook.com  Wed May 15 02:48:33 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 15 May 2013 09:48:33 +0300
Subject: PDF generator decision
In-Reply-To: <877gj0vk2m.fsf@handshake.de>
References: <3f4500ad-784a-401d-a089-e2b7081821e9@googlegroups.com>,
	<877gj0vk2m.fsf@handshake.de>
Message-ID: <BLU176-W2541CD5F8A5297DAEF3DBAD7A20@phx.gbl>

Christian, have you tried pod[1]? You can use create templates in OpenDocument format and then create the PDFs just passing the arguments, like:

args = {'name':'John', 'email':'john at example.com'}
renderer = Renderer('template.odt', args, 'result.odt')renderer.run()



[1] http://appyframework.org/pod.html

----------------------------------------
> To: python-list at python.org
> From: dieter at handshake.de
> Subject: Re: PDF generator decision
> Date: Wed, 15 May 2013 08:22:25 +0200
>
> Christian Jurk <commx at commx.ws> writes:
>
>> ...
>> So far I'd like to ask which is the (probably) best way to create PDFs in Python (3)? It is important for me that I am able to specify not only background graphics, paragaphs, tables and so on but also to specify page headers/footers. The reason is that I have a bunch of documents to be generated (including Invoice templates, Quotes - stuff like that).
>
> High quality layouts, especially those containing (potentially complex
> tables), are very difficult to generate automatically.
>
> I do not suppose that you will find a generic solution - one applicable
> to a wide range of document classes and garanteeing high quality
> layout for almost all of its document instances.
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From carlosnepomuceno at outlook.com  Tue May 14 11:46:30 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 14 May 2013 18:46:30 +0300
Subject: First post
In-Reply-To: <BLU176-W3672D19C9610A9D8404DAFD7A10@phx.gbl>
References: <BLU176-W3672D19C9610A9D8404DAFD7A10@phx.gbl>
Message-ID: <BLU176-W2871AABC0FE67DCDFFCD0D7A10@phx.gbl>

Hi guys! This is my first post on this list.

I'd like have your opinion on how to safely implement WSGI on a production server.

My benchmarks show no performance differences between our PHP and Python environments. I'm using mod_wsgi v3.4 with Apache 2.4.

Is that ok or can it get faster?

Thanks in advance.

Regards,

Carlos 		 	   		  

From krishna2prasad at gmail.com  Tue May 14 15:00:22 2013
From: krishna2prasad at gmail.com (krishna2prasad at gmail.com)
Date: Tue, 14 May 2013 12:00:22 -0700 (PDT)
Subject: Illegal seek error with seek() and os.lseek()
Message-ID: <50bf9366-46e0-4a7f-865b-3f7c7b0f607d@googlegroups.com>

I am trying to use os.open() and os.lseek() methods to operate on a device file in Linux. My code goes something like this -

 # first, open the file as a plain binary
 try:
     self.file = open(/dev/relpcfpga, "r+b", buffering=0)
 
 except IOError:
     raise IOError ('Failed to open.')

 # Figure out file size
  self.file.seek(0, 2)
  self.file_size = self.file.tell()
 

The method seek() complains "OSError: [Errno 29] Illegal seek"
The device relpcfpga is a char device.

The same code works with a normal text file.
I have tried to use os.open() and os.lseek() methods, but see the same error.
Is there a different method to operate on device files?


Thanks!


From marduk at python.net  Tue May 14 16:00:44 2013
From: marduk at python.net (marduk at python.net)
Date: Tue, 14 May 2013 16:00:44 -0400
Subject: Illegal seek error with seek() and os.lseek()
In-Reply-To: <50bf9366-46e0-4a7f-865b-3f7c7b0f607d@googlegroups.com>
References: <50bf9366-46e0-4a7f-865b-3f7c7b0f607d@googlegroups.com>
Message-ID: <1368561644.772.140661231053781.62A9F526@webmail.messagingengine.com>

On Tue, May 14, 2013, at 03:00 PM, krishna2prasad at gmail.com wrote:
> I am trying to use os.open() and os.lseek() methods to operate on a
> device file in Linux. My code goes something like this -
> 
>  # first, open the file as a plain binary
>  try:
>      self.file = open(/dev/relpcfpga, "r+b", buffering=0)
>  
>  except IOError:
>      raise IOError ('Failed to open.')
> 
>  # Figure out file size
>   self.file.seek(0, 2)
>   self.file_size = self.file.tell()
>  
> 
> The method seek() complains "OSError: [Errno 29] Illegal seek"
> The device relpcfpga is a char device.
> 
> The same code works with a normal text file.
> I have tried to use os.open() and os.lseek() methods, but see the same
> error.
> Is there a different method to operate on device files?

Some file streams are not seekable.  Specifically, some (all?) char
devices aren't seekable (because e.g. they can't be rewound or they have
no end).  You'd get the same error in C (well it would return -1).

See also: http://www.linuxintro.org/wiki/Device


From roy at panix.com  Tue May 14 16:02:16 2013
From: roy at panix.com (Roy Smith)
Date: Tue, 14 May 2013 16:02:16 -0400
Subject: Illegal seek error with seek() and os.lseek()
References: <50bf9366-46e0-4a7f-865b-3f7c7b0f607d@googlegroups.com>
Message-ID: <roy-77A32B.16021614052013@news.panix.com>

In article <50bf9366-46e0-4a7f-865b-3f7c7b0f607d at googlegroups.com>,
 krishna2prasad at gmail.com wrote:

> I am trying to use os.open() and os.lseek() methods to operate on a device 
> file in Linux. My code goes something like this -
> 
>  # first, open the file as a plain binary
>  try:
>      self.file = open(/dev/relpcfpga, "r+b", buffering=0)
>  
>  except IOError:
>      raise IOError ('Failed to open.')
> 
>  # Figure out file size
>   self.file.seek(0, 2)
>   self.file_size = self.file.tell()
>  
> 
> The method seek() complains "OSError: [Errno 29] Illegal seek"
> The device relpcfpga is a char device.
> 
> The same code works with a normal text file.
> I have tried to use os.open() and os.lseek() methods, but see the same error.
> Is there a different method to operate on device files?

In general, seek() works on special files, when it makes sense.  But, 
the "in general" part is critical.  Not all devices support the seek 
operation.  I have no idea what /dev/relpcfpga is (a google search for 
relpcfpga came up with exactly one hit -- your post!) so I can't tell 
you if it supports seek() or not.


From andipersti at gmail.com  Tue May 14 16:12:23 2013
From: andipersti at gmail.com (Andreas Perstinger)
Date: Tue, 14 May 2013 22:12:23 +0200
Subject: Illegal seek error with seek() and os.lseek()
In-Reply-To: <50bf9366-46e0-4a7f-865b-3f7c7b0f607d@googlegroups.com>
References: <50bf9366-46e0-4a7f-865b-3f7c7b0f607d@googlegroups.com>
Message-ID: <51929AA7.4020802@gmail.com>

On 14.05.2013 21:00, krishna2prasad at gmail.com wrote:
>   # first, open the file as a plain binary
>   try:
>       self.file = open(/dev/relpcfpga, "r+b", buffering=0)

Aren't you missing the quotes for "/dev/relpcfpga"?

> The method seek() complains "OSError: [Errno 29] Illegal seek"
> The device relpcfpga is a char device.

Are you sure that your device is seekable?
Try

f = open("/dev/relpcfpga", "r+b", buffering=0)
print(f.seekable())

Bye, Andreas


From alok.jadhav at credit-suisse.com  Tue May 14 20:44:10 2013
From: alok.jadhav at credit-suisse.com (Jadhav, Alok)
Date: Wed, 15 May 2013 08:44:10 +0800
Subject: weave in 64 bit strange behavior
Message-ID: <CEE8C35195DB944D9C75ABB15A04193B21E9BA39@EHKG17P32001A.csfb.cs-group.com>

Hi everyone,

 

I realize my previous post was quite unreadable, thanks to my email
client. I am going to report my question here, with slight enhancements.
Apologies for inconvenience caused and spamming your mailboxes.

 

I am facing a strange problem using weave on 64 bit machine.
Specifically with weave's inline function. It has something to do with
weave's catalog. 

 

Similar issues I found in the past (very old)

 

http://mail.scipy.org/pipermail/scipy-dev/2006-June/005908.html 

http://mail.scipy.org/pipermail/scipy-dev/2005-June/003042.html

 

Common things I have in my observation are:

 

-          Already working setup in 32 bit doesn't work in same manner
in 64 bit env

-          Weave recompiles inline code which does not require any
recompilation. This is random behavior.  Whenever weave recompiles I see
a notification "repairing catalog by removing key" in the output which
ends up in the error message "ImportError: DLL load failed: Invalid
access to memory location"

-          Sometimes gcc gets into an infinite loop printing error
message "Looking for python27.dll". Even though the dll is on the path.
This process doesn't end. Had to kill it forcefully. G++ process became
ghost even after killing python process. 

 

Could someone advise what am I missing here. Is there any specific setup
that I need to do? Is there an issue with python 27 64 bit weave
implementation? 

 

Regards,

Alok

 

<CODE>

 

I have a simple script to calculate moving average using weave's inline
function. 

 

source mvg.py

 

import numpy as np

import scipy.weave as weave

import distutils.sysconfig

import distutils.dir_util

import os

 

distutils.sysconfig._config_vars["LDSHARED"]="-LC:\strawberry\c\x86_64-w
64-mingw32\lib"

 

def ExpMovAvg(data,time,lag):

    if (data.size!=time.size):

        print "error in EMA, data and time have different size"

        return None

 

    result=np.repeat(0.0,data.size)

    code="""

    #line 66 "basics.py"

    result(0)=data(0);

    for (int i=0;i<data.size()-1;i++)

    {

        //double alpha=1-(2.0/(lag+1)*(time(i)-time(i-1)));

        double dt=time(i+1)-time(i);

        double alpha=pow(0.13533, dt / lag);

        if(alpha>1)

        {

            alpha=10;

        }

        result(i+1)=(1-alpha)*data(i)+alpha*result(i);

    }

    """

 
weave.inline(code,["data","time","lag","result"],type_converters=weave.c
onverters.blitz,headers=["<math.h>"],compiler="gcc",verbose=2)

    return result

 

source test.py

 

import string

import numpy as np

import mvg

 

print(mvg.ExpMovAvg(np.array(range(10)),np.array(range(10)),2))

 

 

Output:

 

Working output:

 

Y:\STMM\alpha\klse\PROD>c:\python27\python.exe

s:\common\tools\python\python-2.7-64bit\test.py

 

[ 0.          0.          0.63212774  1.49679774  2.44701359  3.42869938

4.42196209  5.41948363  6.41857187  7.41823646]

 

Now if I keep running the script multiple times, sometimes I see correct

output... but suddenly sometimes I get below error.

 

Y:\STMM\alpha\klse\PROD>c:\python27\python.exe
s:\common\tools\python\python-2.7-64bit\test.py

 

repairing catalog by removing key

<weave: compiling>

Looking for python27.dll

running build_ext

running build_src

build_src

building extension "sc_44f3fe3c65d5c3feecb45d9269ac207f5" sources

build_src: building npy-pkg config files

Looking for python27.dll

 

customize Mingw32CCompiler

customize Mingw32CCompiler using build_ext

Looking for python27.dll

customize Mingw32CCompiler

customize Mingw32CCompiler using build_ext

building 'sc_44f3fe3c65d5c3feecb45d9269ac207f5' extension

compiling C++ sources

C compiler: g++ -g -DDEBUG -DMS_WIN64 -O0 -Wall

 

compile options: '-Ic:\python27\lib\site-packages\scipy\weave
-Ic:\python27\lib\site-packages\scipy\weave\scxx
-Ic:\python27\lib\site-packages\scipy\weave\blitz
-Ic:\python27\lib\site-packages\numpy\core\include -Ic:\python27\include
-Ic:\python27\PC -c' 

g++ -g -DDEBUG -DMS_WIN64 -O0 -Wall
-Ic:\python27\lib\site-packages\scipy\weave
-Ic:\python27\lib\site-packages\scipy\weave\scxx
-Ic:\python27\lib\site-packages\scipy\weave\blitz
-Ic:\python27\lib\site-packages\numpy\core\include -Ic:\python27\include
-Ic:\python27\PC -c
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_compiled\sc_44f3f
e3c65d5c3feecb45d9269ac207f5.cpp -o
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_intermediate\comp
iler_2d3e1e2e4de6a91419d2376b162e5342\Release\users\ajadhav2\appdata\loc
al\temp\ajadhav2\python27_compiled\sc_44f3fe3c65d5c3feecb45d9269ac207f5.
o

 

Found executable C:\strawberry\c\bin\g++.exe

g++ -g -DDEBUG -DMS_WIN64 -O0
-Wall-Ic:\python27\lib\site-packages\scipy\weave-Ic:\python27\lib\site-p
ackages\scipy\weave\scxx
-Ic:\python27\lib\site-packages\scipy\weave\blitz
-Ic:\python27\lib\site-packages\numpy\core\include-Ic:\python27\include
-Ic:\python27\PC -c
c:\python27\lib\site-packages\scipy\weave\scxx\weave_imp.cpp -o
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_intermediate\comp
iler_2d3e1e2e4de6a91419d2376b162e5342\Release\python27\lib\site-packages
\scipy\weave\scxx\weave_imp.o

g++ -g -shared
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_intermediate\comp
iler_2d3e1e2e4de6a91419d2376b162e5342\Release\users\ajadhav2\appdata\loc
al\temp\ajadhav2\python27_compiled\sc_44f3fe3c65d5c3feecb45d9269ac207f5.
o
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_intermediate\comp
iler_2d3e1e2e4de6a91419d2376b162e5342\Release\python27\lib\site-packages
\scipy\weave\scxx\weave_imp.o -Lc:\python27\libs
-Lc:\python27\PCbuild\amd64 -lpython27 -lmsvcr90 -o
c:\users\ajadhav2\appdata\local\temp\ajadhav2\python27_compiled\sc_44f3f
e3c65d5c3feecb45d9269ac207f5.pyd

 

running scons

 

Traceback (most recent call last):

  File "s:\common\tools\python\python-2.7-64bit\test.py", line 5, in
<module>
print(mvg.ExpMovAvg(np.array(range(10)),np.array(range(10)),2))

  File "s:\common\tools\python\python-2.7-64bit\mvg.py", line 30, in
ExpMovAvgweave.inline(code,["data","time","lag","result"],
type_converters=weave.converters.blitz,headers=["<math.h>"],compiler="gc
c",verbose=2)

  File "c:\python27\lib\site-packages\scipy\weave\inline_tools.py",
line355, ininline **kw)

  File "c:\python27\lib\site-packages\scipy\weave\inline_tools.py", line
488, in compile_function exec 'import ' + module_name

  

  File "<string>", line 1, in <module> ImportError: DLL load failed:
Invalid access to memory location.

 

Y:\STMM\alpha\klse\PROD>

</CODE>


=============================================================================== 
Please access the attached hyperlink for an important electronic communications disclaimer: 
http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html 
=============================================================================== 

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From formisc at gmail.com  Wed May 15 00:22:05 2013
From: formisc at gmail.com (Andrew Z)
Date: Wed, 15 May 2013 00:22:05 -0400
Subject: IndexError: pop index out of range
Message-ID: <CAPrcKXKuu_rr7veF_qLHz-bcLaBBZf_+RR+mY+zXwxGCO1H0BA@mail.gmail.com>

hello,
 going fru some basic examples and can't figureout why the following errors
out. Help is very much appreciated:
<code>
def front_x(words):
  # +++your code here+++
    print "words passed : ", words
    list_xx = []
    list_temp = words[:]
    print "list_temp -", list_temp
    print "words -", words
    for idx, val in enumerate(words):
        print val, idx
        # str_idx = val.find('x',0,2)
        if val[0] == 'x':
            vl = list_temp.pop(idx)
            list_xx.append(vl)

            print "appending list_xx", list_xx

    list_xx.sort
    list_temp.sort
    print "words sorted : " + str(words)
    print "list_temp sorted : ", list_temp
    list_xx.append(words)
    print "list_xx" + str(list_xx)
    return True

front_x
words passed : ['bbb', 'ccc', 'axx', 'xzz', 'xaa']
list_temp - ['bbb', 'ccc', 'axx', 'xzz', 'xaa']
words - ['bbb', 'ccc', 'axx', 'xzz', 'xaa']
bbb 0
ccc 1
axx 2
xzz 3
appending list_xx ['xzz']
xaa 4
Traceback (most recent call last):
  File
"/home/az/work/Python/Google_Course/google-python-exercises/basic/list1.py",
line 119, in <module>
    main()
  File
"/home/az/work/Python/Google_Course/google-python-exercises/basic/list1.py",
line 100, in main
    test(front_x(['bbb', 'ccc', 'axx', 'xzz', 'xaa']),
  File
"/home/az/work/Python/Google_Course/google-python-exercises/basic/list1.py",
line 55, in front_x
    vl = list_temp.pop(idx)
IndexError: pop index out of range

</code>
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From carlosnepomuceno at outlook.com  Wed May 15 00:53:26 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 15 May 2013 07:53:26 +0300
Subject: IndexError: pop index out of range
In-Reply-To: <CAPrcKXKuu_rr7veF_qLHz-bcLaBBZf_+RR+mY+zXwxGCO1H0BA@mail.gmail.com>
References: <CAPrcKXKuu_rr7veF_qLHz-bcLaBBZf_+RR+mY+zXwxGCO1H0BA@mail.gmail.com>
Message-ID: <BLU176-W3896B5A0463970863AA471D7A20@phx.gbl>

Your "for idx, val in enumerate(words):" is running on words not list_temp.
As you remove from list_temp and keeps parsing words you get the IndexError.
________________________________
> From: formisc at gmail.com 
> Date: Wed, 15 May 2013 00:22:05 -0400 
> Subject: IndexError: pop index out of range 
> To: python-list at python.org 
>  
> hello, 
>   going fru some basic examples and can't figureout why the following  
> errors out. Help is very much appreciated: 
> <code> 
> def front_x(words): 
>    # +++your code here+++ 
>      print "words passed : ", words 
>      list_xx = [] 
>      list_temp = words[:] 
>      print "list_temp -", list_temp 
>      print "words -", words 
>      for idx, val in enumerate(words): 
>          print val, idx 
>          # str_idx = val.find('x',0,2) 
>          if val[0] == 'x': 
>              vl = list_temp.pop(idx) 
>              list_xx.append(vl) 
>  
>              print "appending list_xx", list_xx 
>  
>      list_xx.sort 
>      list_temp.sort 
>      print "words sorted : " + str(words) 
>      print "list_temp sorted : ", list_temp 
>      list_xx.append(words) 
>      print "list_xx" + str(list_xx) 
>      return True 
>  
> front_x 
> words passed : ['bbb', 'ccc', 'axx', 'xzz', 'xaa'] 
> list_temp - ['bbb', 'ccc', 'axx', 'xzz', 'xaa'] 
> words - ['bbb', 'ccc', 'axx', 'xzz', 'xaa'] 
> bbb 0 
> ccc 1 
> axx 2 
> xzz 3 
> appending list_xx ['xzz'] 
> xaa 4 
> Traceback (most recent call last): 
>    File  
> "/home/az/work/Python/Google_Course/google-python-exercises/basic/list1.py",  
> line 119, in <module> 
>      main() 
>    File  
> "/home/az/work/Python/Google_Course/google-python-exercises/basic/list1.py",  
> line 100, in main 
>      test(front_x(['bbb', 'ccc', 'axx', 'xzz', 'xaa']), 
>    File  
> "/home/az/work/Python/Google_Course/google-python-exercises/basic/list1.py",  
> line 55, in front_x 
>      vl = list_temp.pop(idx) 
> IndexError: pop index out of range 
>  
> </code> 
>  
> -- http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From henry.leyh at ipp.mpg.de  Wed May 15 02:34:27 2013
From: henry.leyh at ipp.mpg.de (Henry Leyh)
Date: Wed, 15 May 2013 08:34:27 +0200
Subject: Determine actually given command line arguments
Message-ID: <kmva9j$1hbk$1@gwdu112.gwdg.de>

Hello,
I am writing a program that gets its parameters from a combination of 
config file (using configparser) and command line arguments (using 
argparse).  Now I would also like the program to be able to _write_ a 
configparser config file that contains only the parameters actually 
given on the commandline.  Is there a simple way to determine which 
command line arguments were actually given on the commandline, i.e. does 
argparse.ArgumentParser() know which of its namespace members were 
actually hit during parse_args().

I have tried giving the arguments default values and then looking for 
those having a non-default value but this is really awkward, especially 
if it comes to non-string arguments.  Also, parsing sys.argv looks 
clumsy because you have to keep track of short and long options with and 
without argument etc. i.e. all things that I got argparse for in the 
first place.

Thanks && Greetings,
Henry


From cjw at ncf.ca  Wed May 15 08:03:28 2013
From: cjw at ncf.ca (Colin J. Williams)
Date: Wed, 15 May 2013 08:03:28 -0400
Subject: Determine actually given command line arguments
In-Reply-To: <kmva9j$1hbk$1@gwdu112.gwdg.de>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
Message-ID: <kmvtj0$gbq$1@theodyn.ncf.ca>

On 15/05/2013 2:34 AM, Henry Leyh wrote:
> Hello,
> I am writing a program that gets its parameters from a combination of
> config file (using configparser) and command line arguments (using
> argparse).  Now I would also like the program to be able to _write_ a
> configparser config file that contains only the parameters actually
> given on the commandline.  Is there a simple way to determine which
> command line arguments were actually given on the commandline, i.e. does
> argparse.ArgumentParser() know which of its namespace members were
> actually hit during parse_args().
>
> I have tried giving the arguments default values and then looking for
> those having a non-default value but this is really awkward, especially
> if it comes to non-string arguments.  Also, parsing sys.argv looks
> clumsy because you have to keep track of short and long options with and
> without argument etc. i.e. all things that I got argparse for in the
> first place.
>
> Thanks && Greetings,
> Henry
Try sys.argv

Colin W.


From jpiitula at ling.helsinki.fi  Wed May 15 08:51:37 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 15 May 2013 15:51:37 +0300
Subject: Determine actually given command line arguments
References: <kmva9j$1hbk$1@gwdu112.gwdg.de> <kmvtj0$gbq$1@theodyn.ncf.ca>
Message-ID: <qothai42yp2.fsf@ruuvi.it.helsinki.fi>

Colin J. Williams writes:

> On 15/05/2013 2:34 AM, Henry Leyh wrote:
> > Hello,

> > I am writing a program that gets its parameters from a combination
> > of config file (using configparser) and command line arguments
> > (using argparse).  Now I would also like the program to be able to
> > _write_ a configparser config file that contains only the
> > parameters actually given on the commandline.  Is there a simple
> > way to determine which command line arguments were actually given
> > on the commandline, i.e. does argparse.ArgumentParser() know which
> > of its namespace members were actually hit during parse_args().
> >
> > I have tried giving the arguments default values and then looking
> > for those having a non-default value but this is really awkward,
> > especially if it comes to non-string arguments.  Also, parsing
> > sys.argv looks clumsy because you have to keep track of short and
> > long options with and without argument etc. i.e. all things that I
> > got argparse for in the first place.
> >
> > Thanks && Greetings,
> > Henry

> Try sys.argv

You people should read what you quote, or what you don't quote when
you cut the relevant portion.

Q. ... parsing sys.argv looks clumsy because  ...
A. Try sys.argv

I mean, huh?


From roy at panix.com  Wed May 15 08:24:54 2013
From: roy at panix.com (Roy Smith)
Date: Wed, 15 May 2013 08:24:54 -0400
Subject: Determine actually given command line arguments
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
Message-ID: <roy-C8F8F4.08245415052013@news.panix.com>

In article <kmva9j$1hbk$1 at gwdu112.gwdg.de>,
 Henry Leyh <henry.leyh at ipp.mpg.de> wrote:

> Is there a simple way to determine which 
> command line arguments were actually given on the commandline, i.e. does 
> argparse.ArgumentParser() know which of its namespace members were 
> actually hit during parse_args().

I think what you're looking for is sys.argv:

$ cat argv.py
import sys
print sys.argv

$ python argv.py foo bar
['argv.py', 'foo', 'bar']


From davea at davea.name  Wed May 15 08:51:30 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 15 May 2013 08:51:30 -0400
Subject: Determine actually given command line arguments
In-Reply-To: <roy-C8F8F4.08245415052013@news.panix.com>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
Message-ID: <519384D2.8070406@davea.name>

On 05/15/2013 08:24 AM, Roy Smith wrote:
> In article <kmva9j$1hbk$1 at gwdu112.gwdg.de>,
>   Henry Leyh <henry.leyh at ipp.mpg.de> wrote:
>
>> Is there a simple way to determine which
>> command line arguments were actually given on the commandline, i.e. does
>> argparse.ArgumentParser() know which of its namespace members were
>> actually hit during parse_args().
>
> I think what you're looking for is sys.argv:
>
> $ cat argv.py
> import sys
> print sys.argv
>
> $ python argv.py foo bar
> ['argv.py', 'foo', 'bar']
>

Colin & Roy:
The OP mentioned sys.argv in his original query.

-- 
DaveA


From henry.leyh at ipp.mpg.de  Wed May 15 08:52:59 2013
From: henry.leyh at ipp.mpg.de (Henry Leyh)
Date: Wed, 15 May 2013 14:52:59 +0200
Subject: Determine actually given command line arguments
In-Reply-To: <roy-C8F8F4.08245415052013@news.panix.com>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
Message-ID: <kn00fb$8kc$1@gwdu112.gwdg.de>

On 15.05.2013 14:24, Roy Smith wrote:
> In article <kmva9j$1hbk$1 at gwdu112.gwdg.de>,
>   Henry Leyh <henry.leyh at ipp.mpg.de> wrote:
>
>> Is there a simple way to determine which
>> command line arguments were actually given on the commandline, i.e. does
>> argparse.ArgumentParser() know which of its namespace members were
>> actually hit during parse_args().
>
> I think what you're looking for is sys.argv:
>
> $ cat argv.py
> import sys
> print sys.argv
>
> $ python argv.py foo bar
> ['argv.py', 'foo', 'bar']

Thanks, but as I wrote in my first posting I am aware of sys.argv and 
was hoping to _avoid_ using it because I'd then have to kind of 
re-implement a lot of the stuff already there in argparse, e.g. parsing 
sys.argv for short/long options, flag/parameter options etc.

I was thinking of maybe some sort of flag that argparse sets on those 
optional arguments created with add_argument() that are really given on 
the command line, i.e. those that it stumbles upon them during parse_args().

Regards,
Henry



From oscar.j.benjamin at gmail.com  Wed May 15 09:00:50 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Wed, 15 May 2013 14:00:50 +0100
Subject: Determine actually given command line arguments
In-Reply-To: <kn00fb$8kc$1@gwdu112.gwdg.de>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de>
Message-ID: <CAHVvXxQU8mvwbWTzeAPTksfM=2EuqsEy6u=M-4SriDE+2ab3-A@mail.gmail.com>

On 15 May 2013 13:52, Henry Leyh <henry.leyh at ipp.mpg.de> wrote:
> On 15.05.2013 14:24, Roy Smith wrote:
>>
>> In article <kmva9j$1hbk$1 at gwdu112.gwdg.de>,
>>   Henry Leyh <henry.leyh at ipp.mpg.de> wrote:
>>
>>> Is there a simple way to determine which
>>> command line arguments were actually given on the commandline, i.e. does
>>> argparse.ArgumentParser() know which of its namespace members were
>>> actually hit during parse_args().
>>
>>
>> I think what you're looking for is sys.argv:
>>
>> $ cat argv.py
>> import sys
>> print sys.argv
>>
>> $ python argv.py foo bar
>> ['argv.py', 'foo', 'bar']
>
> Thanks, but as I wrote in my first posting I am aware of sys.argv and was
> hoping to _avoid_ using it because I'd then have to kind of re-implement a
> lot of the stuff already there in argparse, e.g. parsing sys.argv for
> short/long options, flag/parameter options etc.
>
> I was thinking of maybe some sort of flag that argparse sets on those
> optional arguments created with add_argument() that are really given on the
> command line, i.e. those that it stumbles upon them during parse_args().

I don't know about that but I imagine that you could compare values
with their defaults to see which have been changed.


Oscar


From henry.leyh at ipp.mpg.de  Wed May 15 09:50:53 2013
From: henry.leyh at ipp.mpg.de (Henry Leyh)
Date: Wed, 15 May 2013 15:50:53 +0200
Subject: Determine actually given command line arguments
In-Reply-To: <mailman.1697.1368622878.3114.python-list@python.org>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de>
	<mailman.1697.1368622878.3114.python-list@python.org>
Message-ID: <kn03rt$d74$1@gwdu112.gwdg.de>

On 15.05.2013 15:00, Oscar Benjamin wrote:
> On 15 May 2013 13:52, Henry Leyh <henry.leyh at ipp.mpg.de> wrote:
>> On 15.05.2013 14:24, Roy Smith wrote:
>>>
>>> In article <kmva9j$1hbk$1 at gwdu112.gwdg.de>,
>>>    Henry Leyh <henry.leyh at ipp.mpg.de> wrote:
>>>
>>>> Is there a simple way to determine which
>>>> command line arguments were actually given on the commandline, i.e. does
>>>> argparse.ArgumentParser() know which of its namespace members were
>>>> actually hit during parse_args().
>>>
>>>
>>> I think what you're looking for is sys.argv:
>>>
>>> $ cat argv.py
>>> import sys
>>> print sys.argv
>>>
>>> $ python argv.py foo bar
>>> ['argv.py', 'foo', 'bar']
>>
>> Thanks, but as I wrote in my first posting I am aware of sys.argv and was
>> hoping to _avoid_ using it because I'd then have to kind of re-implement a
>> lot of the stuff already there in argparse, e.g. parsing sys.argv for
>> short/long options, flag/parameter options etc.
>>
>> I was thinking of maybe some sort of flag that argparse sets on those
>> optional arguments created with add_argument() that are really given on the
>> command line, i.e. those that it stumbles upon them during parse_args().
>
> I don't know about that but I imagine that you could compare values
> with their defaults to see which have been changed.

Yes, I was trying that and it sort of works with strings if I use 
something sufficiently improbable like "__UNSELECTED__" as default.  But 
it gets difficult with boolean or even number arguments where you just 
may not have valid "improbable" defaults.  You could now say, so what, 
it's the default anyway.  But in my program I would like to distinguish 
between given and not given arguments rather than between default and 
non-default.

Regards,
Henry



From skip at pobox.com  Wed May 15 10:08:12 2013
From: skip at pobox.com (Skip Montanaro)
Date: Wed, 15 May 2013 09:08:12 -0500
Subject: Determine actually given command line arguments
In-Reply-To: <kn03rt$d74$1@gwdu112.gwdg.de>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de>
	<mailman.1697.1368622878.3114.python-list@python.org>
	<kn03rt$d74$1@gwdu112.gwdg.de>
Message-ID: <CANc-5UxmAhWZHLYg7GPs1OVBWaTM8YR-ZFyL=jXD0u+x9rhkLg@mail.gmail.com>

> Yes, I was trying that and it sort of works with strings if I use something sufficiently improbable like "__UNSELECTED__" as default.  But it gets difficult with boolean or even number arguments where you just may not have valid "improbable" defaults.  You could now say, so what, it's the default anyway.  But in my program I would like to distinguish between given and not given arguments rather than between default and non-default.

Initialize all your arg variables to None, then after command line
processing, any which remain as None weren't set on the command line.
At that point, set them to the actual defaults.  I think that's a
pretty common idiom.

Note: I am an old cranky dude and still use getopt.  This idiom is
pretty easy there.  YMMV with argparse or optparse.

Skip


From wayne at waynewerner.com  Wed May 15 10:16:35 2013
From: wayne at waynewerner.com (Wayne Werner)
Date: Wed, 15 May 2013 09:16:35 -0500 (CDT)
Subject: Determine actually given command line arguments
In-Reply-To: <kn03rt$d74$1@gwdu112.gwdg.de>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de>
	<mailman.1697.1368622878.3114.python-list@python.org>
	<kn03rt$d74$1@gwdu112.gwdg.de>
Message-ID: <alpine.DEB.2.02.1305150915280.3322@gilgamesh>

On Wed, 15 May 2013, Henry Leyh wrote:
> Yes, I was trying that and it sort of works with strings if I use something 
> sufficiently improbable like "__UNSELECTED__" as default.  But it gets 
> difficult with boolean or even number arguments where you just may not have 
> valid "improbable" defaults.  You could now say, so what, it's the default 
> anyway.  But in my program I would like to distinguish between given and not 
> given arguments rather than between default and non-default.

Have you looked into docopt? It's pretty awesome, and might really help in 
this case.

HTH,
-W


From henry.leyh at ipp.mpg.de  Wed May 15 10:39:59 2013
From: henry.leyh at ipp.mpg.de (Henry Leyh)
Date: Wed, 15 May 2013 16:39:59 +0200
Subject: Determine actually given command line arguments
In-Reply-To: <mailman.1699.1368626900.3114.python-list@python.org>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de>
	<mailman.1697.1368622878.3114.python-list@python.org>
	<kn03rt$d74$1@gwdu112.gwdg.de>
	<mailman.1699.1368626900.3114.python-list@python.org>
Message-ID: <kn06nv$glc$1@gwdu112.gwdg.de>

On 15.05.2013 16:08, Skip Montanaro wrote:
>> Yes, I was trying that and it sort of works with strings if I use something sufficiently improbable like "__UNSELECTED__" as default.  But it gets difficult with boolean or even number arguments where you just may not have valid "improbable" defaults.  You could now say, so what, it's the default anyway.  But in my program I would like to distinguish between given and not given arguments rather than between default and non-default.
>
> Initialize all your arg variables to None, then after command line
> processing, any which remain as None weren't set on the command line.
> At that point, set them to the actual defaults.  I think that's a
> pretty common idiom.
>
> Note: I am an old cranky dude and still use getopt.  This idiom is
> pretty easy there.  YMMV with argparse or optparse.

Unfortunately, argparse wants to know the type of the argument and the 
boolean arguments (those with action=store_true) can't be initialized 
with None.

However, maybe I could convert boolean arguments to something like

   parser.add_argument('--foo', type=str, nargs='?', const='True', 
default=None)

I'd then have to check for string 'True' rather than for boolean True, 
though.

Regards,
Henry



From skip at pobox.com  Wed May 15 10:51:43 2013
From: skip at pobox.com (Skip Montanaro)
Date: Wed, 15 May 2013 09:51:43 -0500
Subject: Determine actually given command line arguments
In-Reply-To: <kn06nv$glc$1@gwdu112.gwdg.de>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de>
	<mailman.1697.1368622878.3114.python-list@python.org>
	<kn03rt$d74$1@gwdu112.gwdg.de>
	<mailman.1699.1368626900.3114.python-list@python.org>
	<kn06nv$glc$1@gwdu112.gwdg.de>
Message-ID: <CANc-5Uy6s7G60btWRAoxrgYnQLG3niXPJtbYnki+Gi4yCWd9tg@mail.gmail.com>

> However, maybe I could ...

... switch to getopt? <wink>

Skip


From roy at panix.com  Wed May 15 11:29:18 2013
From: roy at panix.com (Roy Smith)
Date: 15 May 2013 11:29:18 -0400
Subject: Determine actually given command line arguments
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de>
Message-ID: <kn09ke$kkf$1@panix2.panix.com>

In article <kn00fb$8kc$1 at gwdu112.gwdg.de>,
Henry Leyh  <henry.leyh at ipp.mpg.de> wrote:
>On 15.05.2013 14:24, Roy Smith wrote:
>> In article <kmva9j$1hbk$1 at gwdu112.gwdg.de>,
>>   Henry Leyh <henry.leyh at ipp.mpg.de> wrote:
>>
>>> Is there a simple way to determine which
>>> command line arguments were actually given on the commandline, i.e. does
>>> argparse.ArgumentParser() know which of its namespace members were
>>> actually hit during parse_args().
>>
>> I think what you're looking for is sys.argv:
>>
>> $ cat argv.py
>> import sys
>> print sys.argv
>>
>> $ python argv.py foo bar
>> ['argv.py', 'foo', 'bar']
>
>Thanks, but as I wrote in my first posting I am aware of sys.argv and 
>was hoping to _avoid_ using it because I'd then have to kind of 
>re-implement a lot of the stuff already there in argparse, e.g. parsing 
>sys.argv for short/long options, flag/parameter options etc.

Sorry, I missed that.

I'm not clear on exactly what you're trying to do.  You say:

> Now I would also like the program to be able to _write_ a 
> configparser config file that contains only the parameters actually 
> given on the commandline. 

I'm guessing what you're trying to do is parse the command line first,
then anything that was set there can get overridden by a value in the
config file?  That seems backwards.  Usually, the order is:

1) built-in default
2) config file (possibly a system config file, then a per-user one)
3) environment variable
4) command-line argument

It sounds like you're doing it in the reverse order -- allowing the
config file to override the command line.


From henry.leyh at ipp.mpg.de  Thu May 16 01:43:42 2013
From: henry.leyh at ipp.mpg.de (Henry Leyh)
Date: Thu, 16 May 2013 07:43:42 +0200
Subject: Determine actually given command line arguments
In-Reply-To: <kn09ke$kkf$1@panix2.panix.com>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de> <kn09ke$kkf$1@panix2.panix.com>
Message-ID: <kn1rme$2cq2$1@gwdu112.gwdg.de>

On 15.05.2013 17:29, Roy Smith wrote:
> In article <kn00fb$8kc$1 at gwdu112.gwdg.de>,
> Henry Leyh  <henry.leyh at ipp.mpg.de> wrote:
>> On 15.05.2013 14:24, Roy Smith wrote:
>>> In article <kmva9j$1hbk$1 at gwdu112.gwdg.de>,
>>>    Henry Leyh <henry.leyh at ipp.mpg.de> wrote:
>>>
>>>> Is there a simple way to determine which
>>>> command line arguments were actually given on the commandline, i.e. does
>>>> argparse.ArgumentParser() know which of its namespace members were
>>>> actually hit during parse_args().
>>>
>>> I think what you're looking for is sys.argv:
>>>
>>> $ cat argv.py
>>> import sys
>>> print sys.argv
>>>
>>> $ python argv.py foo bar
>>> ['argv.py', 'foo', 'bar']
>>
>> Thanks, but as I wrote in my first posting I am aware of sys.argv and
>> was hoping to _avoid_ using it because I'd then have to kind of
>> re-implement a lot of the stuff already there in argparse, e.g. parsing
>> sys.argv for short/long options, flag/parameter options etc.
>
> Sorry, I missed that.
>
> I'm not clear on exactly what you're trying to do.  You say:
>
>> Now I would also like the program to be able to _write_ a
>> configparser config file that contains only the parameters actually
>> given on the commandline.
>
> I'm guessing what you're trying to do is parse the command line first,
> then anything that was set there can get overridden by a value in the
> config file?  That seems backwards.  Usually, the order is:
>
> 1) built-in default
> 2) config file (possibly a system config file, then a per-user one)
> 3) environment variable
> 4) command-line argument
>
> It sounds like you're doing it in the reverse order -- allowing the
> config file to override the command line.

No.  The program reads a general config file in $HOME, something like 
~/.programrc; then parses the command like for '-c FILE' and, if FILE is 
present reads it; then parses the command line remains for more 
arguments which overwrite everything previously set.  (For the record, 
this split parsing is done with two argparse parsers.  The first parses 
for '-c FILE' with parse_known_args().  If there is a FILE, its contents 
is used as defaults for a second parser (using set_options()) which then 
parses the remains that were returned by the first parser's 
parse_known_args().)

But now I would also like to be able to _write_ such a config file FILE 
that can be read in a later run.  And FILE should contain only those 
arguments that were given on the command line.

Say, I tell argparse to look for arguments -s|--sopt STRING, -i|--iopt 
INT, -b|--bopt [BOOL], -C CONFFILE.  Then 'prog -s bla -i 42 -C cfile' 
should produce a confparser compatible cfile which contains

   [my_options]
   sopt = blah
   iopt = 42

and not 'bopt = False' (if False was the program's default for bopt).

Regards,
Henry



From jpiitula at ling.helsinki.fi  Thu May 16 02:08:45 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 16 May 2013 09:08:45 +0300
Subject: Determine actually given command line arguments
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de> <kn09ke$kkf$1@panix2.panix.com>
	<kn1rme$2cq2$1@gwdu112.gwdg.de>
Message-ID: <qot7gizmp76.fsf@ruuvi.it.helsinki.fi>

Henry Leyh writes:

> But now I would also like to be able to _write_ such a config file
> FILE that can be read in a later run.  And FILE should contain only
> those arguments that were given on the command line.
> 
> Say, I tell argparse to look for arguments -s|--sopt STRING,
> -i|--iopt INT, -b|--bopt [BOOL], -C CONFFILE.  Then 'prog -s bla -i
> 42 -C cfile' should produce a confparser compatible cfile which
> contains
> 
>    [my_options]
>    sopt = blah
>    iopt = 42
> 
> and not 'bopt = False' (if False was the program's default for
> bopt).

Could you instead write those options that differ from the defaults?
You could parse an actual command line and an empty command line, and
work out the difference.

So 'prog -i 3' would not cause 'iopt = 3' to be written if 3 is the
default for iopt, but would that be a problem?


From henry.leyh at ipp.mpg.de  Thu May 16 03:29:50 2013
From: henry.leyh at ipp.mpg.de (Henry Leyh)
Date: Thu, 16 May 2013 09:29:50 +0200
Subject: Determine actually given command line arguments
In-Reply-To: <qot7gizmp76.fsf@ruuvi.it.helsinki.fi>
References: <kmva9j$1hbk$1@gwdu112.gwdg.de>
	<roy-C8F8F4.08245415052013@news.panix.com>
	<kn00fb$8kc$1@gwdu112.gwdg.de> <kn09ke$kkf$1@panix2.panix.com>
	<kn1rme$2cq2$1@gwdu112.gwdg.de>
	<qot7gizmp76.fsf@ruuvi.it.helsinki.fi>
Message-ID: <kn21te$2jis$1@gwdu112.gwdg.de>

On 16.05.2013 08:08, Jussi Piitulainen wrote:
> Henry Leyh writes:
>
>> But now I would also like to be able to _write_ such a config file
>> FILE that can be read in a later run.  And FILE should contain only
>> those arguments that were given on the command line.
>>
>> Say, I tell argparse to look for arguments -s|--sopt STRING,
>> -i|--iopt INT, -b|--bopt [BOOL], -C CONFFILE.  Then 'prog -s bla -i
>> 42 -C cfile' should produce a confparser compatible cfile which
>> contains
>>
>>     [my_options]
>>     sopt = blah
>>     iopt = 42
>>
>> and not 'bopt = False' (if False was the program's default for
>> bopt).
>
> Could you instead write those options that differ from the defaults?
> You could parse an actual command line and an empty command line, and
> work out the difference.
>
> So 'prog -i 3' would not cause 'iopt = 3' to be written if 3 is the
> default for iopt, but would that be a problem?

That's what the program does at the moment.  However, I'm not quite 
happy with it.  Generally, the user doesn't know what's the default and 
it would be confusing if 'prog -i 3' doesn't make 'iopt = 3' turn up in 
the file at the end.  There may also be the case when the user (for 
whatever reason) _wants_ the default in the file.

I think I will try the opposite instead: the program writes the whole 
set of options to the file.  This would produce a complete and 
consistent configuration which automatically reflects the hierarchy in 
which the options were set.  And the user can sort it out by hand if he 
wants.

Regards,
Henry



From wzab01 at gmail.com  Wed May 15 07:18:03 2013
From: wzab01 at gmail.com (wzab)
Date: Wed, 15 May 2013 04:18:03 -0700 (PDT)
Subject: Python 2.7.x - problem with obejct.__init__() not accepting *args and
	**kwargs
Message-ID: <f4ce525a-2728-4ad6-9858-e9005534ee54@bz1g2000vbb.googlegroups.com>

I had to implement in Python 2.7.x a system which heavily relies on
multiple inheritance.
Working on that, I have came to very simplistic code which isolates
the problem:
(The essential thing is that each base class receives all arguments
and uses only those,
which it understands).

class a(object):
  def __init__(self,*args,**kwargs):
    super(a,self).__init__(*args,**kwargs)
    print args
    print kwargs
    print "init in a"

class b(object):
  def __init__(self,*args,**kwargs):
    super(b,self).__init__(*args,**kwargs)
    print args
    print kwargs
    print "init in b"

class c(a,b):
  def __init__(self,*args,**kwargs):
    super(c,self).__init__(*args,**kwargs)
    print args
    print kwargs
    print "init in c"

z=c(test=23,data="eee")

In Python 2.5.2 the above code works correctly, and produces:

$python test1.py
()
{'test': 23, 'data': 'eee'}
init in b
()
{'test': 23, 'data': 'eee'}
init in a
()
{'test': 23, 'data': 'eee'}
init in c

Unfortunately in Python 2.7 the above code generates an exception:
$ python test1.py
Traceback (most recent call last):
  File "test1.py", line 22, in <module>
    z=c(test=23,data="eee")
  File "test1.py", line 17, in __init__
    super(c,self).__init__(*args,**kwargs)
  File "test1.py", line 3, in __init__
    super(a,self).__init__(*args,**kwargs)
  File "test1.py", line 10, in __init__
    super(b,self).__init__(*args,**kwargs)
TypeError: object.__init__() takes no parameters

I have found a workaround:

# Class my_object added only as workaround for a problem with
# object.__init__() not accepting any arguments.

class my_object(object):
  def __init__(self,*args,**kwargs):
    super(my_object,self).__init__()

class a(my_object):
  def __init__(self,*args,**kwargs):
    super(a,self).__init__(*args,**kwargs)
    print args
    print kwargs
    print "init in a"

class b(my_object):
  def __init__(self,*args,**kwargs):
    super(b,self).__init__(*args,**kwargs)
    print args
    print kwargs
    print "init in b"

class c(a,b):
  def __init__(self,*args,**kwargs):
    super(c,self).__init__(*args,**kwargs)
    print args
    print kwargs
    print "init in c"

z=c(test=23,data="eee")

The above works correctly, producing the same results as the first
code in Python 2.5.2,
but anyway it seems to me just a dirty trick...
What is the proper way to solve that problem in Python 2.7.3?

--
TIA,
Wojtek


From oscar.j.benjamin at gmail.com  Wed May 15 08:16:09 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Wed, 15 May 2013 13:16:09 +0100
Subject: Python 2.7.x - problem with obejct.__init__() not accepting *args
	and **kwargs
In-Reply-To: <f4ce525a-2728-4ad6-9858-e9005534ee54@bz1g2000vbb.googlegroups.com>
References: <f4ce525a-2728-4ad6-9858-e9005534ee54@bz1g2000vbb.googlegroups.com>
Message-ID: <CAHVvXxTnMKvrzCp9cyHsSc_WM7ymRTJdnw+mBs2801cz09a7tg@mail.gmail.com>

On 15 May 2013 12:18, wzab <wzab01 at gmail.com> wrote:
> I had to implement in Python 2.7.x a system which heavily relies on
> multiple inheritance.
> Working on that, I have came to very simplistic code which isolates
> the problem:
> (The essential thing is that each base class receives all arguments
> and uses only those,
> which it understands).
>
[snip]
>
> I have found a workaround:
>
> # Class my_object added only as workaround for a problem with
> # object.__init__() not accepting any arguments.
[snip]
>
> The above works correctly, producing the same results as the first
> code in Python 2.5.2,
> but anyway it seems to me just a dirty trick...
> What is the proper way to solve that problem in Python 2.7.3?

I don't generally use super() but I did see some advice about it in
this article:
https://fuhm.net/super-harmful/

>From the conclusion:
"Never use positional arguments in __init__ or __new__. Always use
keyword args, and always call them as keywords, and always pass all
keywords on to super."


Oscar


From ian.g.kelly at gmail.com  Wed May 15 11:41:35 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 15 May 2013 09:41:35 -0600
Subject: Python 2.7.x - problem with obejct.__init__() not accepting *args
	and **kwargs
In-Reply-To: <CAHVvXxTnMKvrzCp9cyHsSc_WM7ymRTJdnw+mBs2801cz09a7tg@mail.gmail.com>
References: <f4ce525a-2728-4ad6-9858-e9005534ee54@bz1g2000vbb.googlegroups.com>
	<CAHVvXxTnMKvrzCp9cyHsSc_WM7ymRTJdnw+mBs2801cz09a7tg@mail.gmail.com>
Message-ID: <CALwzid=jS_fHpvMNcAYiXAh073zEAZd-yX8FjK4r7sVBZzZ5-A@mail.gmail.com>

On Wed, May 15, 2013 at 6:16 AM, Oscar Benjamin
<oscar.j.benjamin at gmail.com> wrote:
> I don't generally use super() but I did see some advice about it in
> this article:
> https://fuhm.net/super-harmful/
>
> From the conclusion:
> "Never use positional arguments in __init__ or __new__. Always use
> keyword args, and always call them as keywords, and always pass all
> keywords on to super."

While that article is a good read, this one is a bit better on giving
advice about how to practically use super:

http://rhettinger.wordpress.com/2011/05/26/super-considered-super/


From steve+comp.lang.python at pearwood.info  Wed May 15 22:06:11 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 16 May 2013 02:06:11 GMT
Subject: Python 2.7.x - problem with obejct.__init__() not accepting *args
	and **kwargs
References: <f4ce525a-2728-4ad6-9858-e9005534ee54@bz1g2000vbb.googlegroups.com>
	<mailman.1695.1368620192.3114.python-list@python.org>
Message-ID: <51943f13$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Wed, 15 May 2013 13:16:09 +0100, Oscar Benjamin wrote:


> I don't generally use super() 

Then you should, especially in Python 3.

If you're not using super in single-inheritance classes, then you're 
merely making your own code harder to read and write, and unnecessarily 
difficult for others to use with multiple-inheritance.

If you're not using super in multiple-inheritance[1] classes, then your 
code is probably buggy.

There really is no good reason to avoid super in Python 3.


> but I did see some advice about it in this article:
> https://fuhm.net/super-harmful/

It's not a good article. The article started off claiming that super was 
harmful, hence the URL. He's had to back-pedal, and *hard*. The problem 
isn't that super is harmful, it is that the problem being solved -- 
generalized multiple inheritance -- is inherently a fiendishly difficult 
problem to solve. Using super and cooperative multiple inheritance makes 
it a merely difficult but tractable problem.

The above article is useful to see the sorts of issues that can come up 
in multiple inheritance, and perhaps as an argument for avoiding MI 
(except in the tamed versions provided by mixins or straits). But as an 
argument against super? No.

A much better article about super is:

http://rhettinger.wordpress.com/2011/05/26/super-considered-super/


> From the conclusion:
> "Never use positional arguments in __init__ or __new__. Always use
> keyword args, and always call them as keywords, and always pass all
> keywords on to super."

Even that advice is wrong. See Super Considered Super above.




[1] To be precise: one can write mixin classes without super, and 
strictly speaking mixins are a form of multiple inheritance, but it is a 
simplified version of multiple inheritance that avoids most of the 
complications.


-- 
Steven


From ian.g.kelly at gmail.com  Thu May 16 02:37:53 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 16 May 2013 00:37:53 -0600
Subject: Python 2.7.x - problem with obejct.__init__() not accepting *args
	and **kwargs
In-Reply-To: <51943f13$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <f4ce525a-2728-4ad6-9858-e9005534ee54@bz1g2000vbb.googlegroups.com>
	<mailman.1695.1368620192.3114.python-list@python.org>
	<51943f13$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CALwzidngDGRJJhrhx4eYjTN511CBkVHw3WraMq+OW3_jmALHMA@mail.gmail.com>

On Wed, May 15, 2013 at 8:06 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Wed, 15 May 2013 13:16:09 +0100, Oscar Benjamin wrote:
>
>
>> I don't generally use super()
>
> Then you should, especially in Python 3.
>
> If you're not using super in single-inheritance classes, then you're
> merely making your own code harder to read and write, and unnecessarily
> difficult for others to use with multiple-inheritance.
>
> If you're not using super in multiple-inheritance[1] classes, then your
> code is probably buggy.
>
> There really is no good reason to avoid super in Python 3.

The Python 3 syntactic sugar is the primary reason that I've finally
started using super in single-inheritance classes.  The magicalness of
it still disturbs me a bit, though.

>>> class A:
...     def __str__(self):
...         return super().__str__()
...
>>> class B:
...     __str__ = A.__str__
...
>>> A().__str__
<bound method A.__str__ of <__main__.A object at 0x0289E3B0>>
>>> str(A())
'<__main__.A object at 0x0289E270>'
>>> B().__str__
<bound method B.__str__ of <__main__.B object at 0x0289E470>>

The transplanted __str__ method is considered a method of B by Python...

>>> str(B())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in __str__
TypeError: super(type, obj): obj must be an instance or subtype of type

But you can't use it because the super() call is irrevocably tied to
class A.  :-P

Of course the same is true with the syntax "super(A, self)", but at
least with that syntax it is clear that the method is explicitly
referencing class A, and so should not be expected to work correctly
in class B.  By contrast the syntax "super()" looks misleadingly
generic.


From oscar.j.benjamin at gmail.com  Thu May 16 06:31:08 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 16 May 2013 11:31:08 +0100
Subject: Python 2.7.x - problem with obejct.__init__() not accepting *args
	and **kwargs
In-Reply-To: <51943f13$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <f4ce525a-2728-4ad6-9858-e9005534ee54@bz1g2000vbb.googlegroups.com>
	<mailman.1695.1368620192.3114.python-list@python.org>
	<51943f13$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAHVvXxTc03VNMLiGo5TX1FORkvEh1a7kj1OM52pMyjTO_vOcwg@mail.gmail.com>

On 16 May 2013 03:06, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Wed, 15 May 2013 13:16:09 +0100, Oscar Benjamin wrote:
>
>
>> I don't generally use super()
>
> Then you should, especially in Python 3.
>
> If you're not using super in single-inheritance classes, then you're
> merely making your own code harder to read and write, and unnecessarily
> difficult for others to use with multiple-inheritance.
>
> If you're not using super in multiple-inheritance[1] classes, then your
> code is probably buggy.
>
> There really is no good reason to avoid super in Python 3.

I should have been clearer. I don't generally use super() because I
don't generally use Python in a very object-oriented way. My comment
was intended as a qualification of my advice rather than a suggestion
that there is something wrong with super(). I can certainly see how
that would be misinterpreted given the article I linked to:

>> but I did see some advice about it in this article:
>> https://fuhm.net/super-harmful/
>
> It's not a good article. The article started off claiming that super was
> harmful, hence the URL. He's had to back-pedal, and *hard*. The problem
> isn't that super is harmful, it is that the problem being solved --
> generalized multiple inheritance -- is inherently a fiendishly difficult
> problem to solve. Using super and cooperative multiple inheritance makes
> it a merely difficult but tractable problem.
>
> The above article is useful to see the sorts of issues that can come up
> in multiple inheritance, and perhaps as an argument for avoiding MI
> (except in the tamed versions provided by mixins or straits). But as an
> argument against super? No.

I read that article when I was trying to do something with multiple
inheritance. It was helpful to me at that time as it explained why
whatever I was trying to do (I don't remember) was never really going
to work.

>
> A much better article about super is:
>
> http://rhettinger.wordpress.com/2011/05/26/super-considered-super/

This is a good article and I read it after Ian posted it.

>
>
>> From the conclusion:
>> "Never use positional arguments in __init__ or __new__. Always use
>> keyword args, and always call them as keywords, and always pass all
>> keywords on to super."
>
> Even that advice is wrong. See Super Considered Super above.

Raymond's two suggestions for signature are:
'''
One approach is to stick with a fixed signature using positional
arguments. This works well with methods like __setitem__ which have a
fixed signature of two arguments, a key and a value. This technique is
shown in the LoggingDict example where __setitem__ has the same
signature in both LoggingDict and dict.

A more flexible approach is to have every method in the ancestor tree
cooperatively designed to accept keyword arguments and a
keyword-arguments dictionary, to remove any arguments that it needs,
and to forward the remaining arguments using **kwds, eventually
leaving the dictionary empty for the final call in the chain.
'''

The first cannot be used with object.__init__ and the second is not
what the OP wants. I think from the article that the appropriate
suggestion is to do precisely what the OP has done and make everything
a subclass of a root class that has the appropriate signature. Perhaps
instead of calling it my_object it could have a meaningful name
related to what the subclasses are actually for and then it wouldn't
seem so much like a dirty trick.

> [1] To be precise: one can write mixin classes without super, and
> strictly speaking mixins are a form of multiple inheritance, but it is a
> simplified version of multiple inheritance that avoids most of the
> complications.

They're also mostly the only kind of multiple inheritance that I would
think of using.


Oscar


From abradley201 at gmail.com  Wed May 15 12:56:59 2013
From: abradley201 at gmail.com (Andrew Bradley)
Date: Wed, 15 May 2013 12:56:59 -0400
Subject: Question re: objects and square grids
Message-ID: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>

Hello everyone.

I am having a good time programming with Python 3.3 and Pygame. Pygame
seems like the perfect platform for the kind of simple games that I want to
make.

What I have currently programmed is basically a drawn rectangle filled with
200 squares, each side of the squares being 43 pixels. The rectangle is 20
squares by 10 squares.

This grid is what I want to have the entire game on. There will be pieces
that move certain numbers of squares, perform actions that effect pieces on
certain squares, etc. The possibilities are endless.

So what I am now trying to do is organize these squares into objects that I
can easily reference when programming things related to the squares.

So far, I have done this:

A1 = pygame.Rect(10, 12, 43, 43)
A2
A3
A4
B1
B2
etc.

where said integers are the precise location of the top left-most square
for A1, and onward down the line. I would guess that I could continue on in
such a fashion, with appropriate box names for each square. But I'm running
into the problem of confirming that the code above actually does something
useful. For example, I would love to be able to turn A1 a different color,
but how does this work? How do I actually utilize these object variable
names? Are there methods that I am not aware of, because most things I try
tend to do nothing or crash the game. For example, A1.fill(BLUE) does not
work.

Any general advice about how to organize my squares into something that is
easy to program for would be VERY appreciated. Basically all the games I
want to make involve square grids like this, so I want to know as much
about them as possible.

Thank you very much for reading this,
Andrew
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From davea at davea.name  Wed May 15 13:55:34 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 15 May 2013 13:55:34 -0400
Subject: Question re: objects and square grids
In-Reply-To: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
References: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
Message-ID: <5193CC16.80304@davea.name>

On 05/15/2013 12:56 PM, Andrew Bradley wrote:
> Hello everyone.
>
> I am having a good time programming with Python 3.3 and Pygame. Pygame
> seems like the perfect platform for the kind of simple games that I want to
> make.
>

Pygame indeed looks pretty good to me as well.  But I haven't done 
anything with it, so I can't give you specific Pygame advice.


>      <SNNIP>
>
> So far, I have done this:
>
> A1 = pygame.Rect(10, 12, 43, 43)
> A2
> A3
> A4
> B1
> B2
> etc.
>

This is a code smell in Python (or any reasonable language).  I'd 
suggest that instead of trying to have 200 separate global variables, 
you have one, maybe called grid, as follows:

maxrows = 10
maxcols = 20
grid = []
for row in range(maxrows):
     rowdata = []
     for column in range(maxcols):
         arg1 = ...
         arg2 = ...
         arg3 = ...
         arg4 = ...
         rowdata.append(pygame.Rect(arg1, arg2, arg3, arg4)
     grid.append(rowdata)


Now, this can be done shorter with list comprehensions, but I figured 
this would be clearer for you.  I also may have the 10 and 20 reversed, 
but you can work that out.

You'd need to make four formulae to get the four arguments to the Rect 
call, using row and column respectively.  Remember that row and column 
will be numbered from zero, not from one.

But now, you can either address a single rect by
    grid[4][8]

or you can do something to all of them, or to an entire row, or to an 
entire column, pretty easily.


While you're testing your formulae, you might want to replace the 
rowdata.append line with something like:

         rowdata.append( (arg1, arg2, arg3, arg4) )


And perhaps your maxrows, maxcols might be lower while you're testing.

And you can just print grid to see how those arguments are looking.

-- 
DaveA


From davea at davea.name  Wed May 15 15:57:52 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 15 May 2013 15:57:52 -0400
Subject: Question re: objects and square grids
In-Reply-To: <5193CC16.80304@davea.name>
References: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
	<5193CC16.80304@davea.name>
Message-ID: <5193E8C0.1060004@davea.name>

On 05/15/2013 02:14 PM, Andrew Bradley wrote:

Please reply on the list, not privately, unless it's something like a 
simple thank-you.  Typically, you'd do a reply-all, then delete the 
people other than the list itself.  Or if you're using Thunderbird, you 
could just reply-list.

 > Thank you very much for your response: it seems excellent, but I'm 
afraid I
 > do not understand it fully. Your code here:
 >
 > maxrows = 10
 > maxcols = 20
 > grid = []
 > for row in range(maxrows):
 >      rowdata = []
 >      for column in range(maxcols):
 >          arg1 = ...
 >          arg2 = ...
 >          arg3 = ...
 >          arg4 = ...
 >          rowdata.append(pygame.Rect(arg
 > 1, arg2, arg3, arg4)
 >      grid.append(rowdata)
 >
 > Seems very good, but keep in mind I just started programming last 
week, and
 > this is hard for me to wrap my head around. Do I really just write grid =
 > []? or is this like a def grid(): function?

This code was intended to replace the 200 lines you started, A1= 
pygame... A2=  A3=   etc.  I'd have put them inside a function, but this 
is just one of the things I'd have initialized in such a function.  grid 
is a list of lists, not a function.


 > What do you mean by rowdata = []?

[] is the way you define an empty list.  Another way might be:
     rowdata = list()


 > And how exactly would I make the formula for a rect call?

Well, for row==0 and col==0, you say you wanted 10, 12, 43, and 43 for 
the four parameters.   But you never said how you were going to 
(manually) calculate those numbers for other cells.  Only once you've 
decided that can you fill in "formulas" for arg1 and arg2.  I suspect 
that arg3 and arg4 are simply 43 and 43 respectively, since you want all 
the cells to be the same size.

taking my clue from Ian, I might try:

     x_offset = 10
     y_offset = 12
     width = height = 43
     arg1 = column * width + x_offset
     arg2 = row * height + y_offset
     arg3 = width
     arg4 = height

That assumes that there is no gap between cells in this grid.  If you 
want a gap, then the width value used in the arg1 formula would be more 
than 43 (width).  Likewise the height value used in the arg2 formula 
would be more than 43 (height).

 > If there's a good website for these kind of details, I would 
appreciate that too.

You cannot begin to write a non-trivial program in Python without 
understanding lists pretty thoroughly.  Perhaps you should start with 
Alan Gauld's tutorial, which doesn't assume previous programming experience.
    http://www.alan-g.me.uk/

I haven't studied it, as Python was about my 35th programming language. 
  But he's very active on Python-tutor, and explains things very well. 
So his website is probably very good as well.

Now, as you can see from Ian's message, writing a game using pygame will 
require quite a bit of other understanding.  He demonstrates with 
classes to represent cells, which is indeed what I'd do.  But I suspect 
you're not nearly ready to consider writing classes.  (You use classes 
all the time.  For example, 5 is an instance of class int.)


--
DaveA


-- 
DaveA


From abradley201 at gmail.com  Wed May 15 16:35:57 2013
From: abradley201 at gmail.com (Andrew Bradley)
Date: Wed, 15 May 2013 16:35:57 -0400
Subject: Question re: objects and square grids
In-Reply-To: <5193E8C0.1060004@davea.name>
References: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
	<5193CC16.80304@davea.name> <5193E8C0.1060004@davea.name>
Message-ID: <CAPp_YbVBm2444Ea-pUy2Zn2YbB1mKmDoasmNXp7DPAbs8Sra4g@mail.gmail.com>

Now I want to show you what I have written:

row = (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
column = (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20)
SQUARESIZE = 43

grid = []
for row in range(10):
    row_squares = []
    for column in range(20):
        rect = Rect(12 + column * SQUARESIZE, 10 + row * SQUARESIZE,
SQUARESIZE, SQUARESIZE)
        row_squares.append(rect)
    grid.append(row_squares)

It appears to be working (that is, the program still runs without
crashing). So now, how can I utilize this new grid list? Thank you for the
help so far, I feel like the entire grid is now being worked out.
-Andrew



On Wed, May 15, 2013 at 3:57 PM, Dave Angel <davea at davea.name> wrote:

> On 05/15/2013 02:14 PM, Andrew Bradley wrote:
>
> Please reply on the list, not privately, unless it's something like a
> simple thank-you.  Typically, you'd do a reply-all, then delete the people
> other than the list itself.  Or if you're using Thunderbird, you could just
> reply-list.
>
> > Thank you very much for your response: it seems excellent, but I'm
> afraid I
> > do not understand it fully. Your code here:
>
> >
> > maxrows = 10
> > maxcols = 20
> > grid = []
> > for row in range(maxrows):
> >      rowdata = []
> >      for column in range(maxcols):
> >          arg1 = ...
> >          arg2 = ...
> >          arg3 = ...
> >          arg4 = ...
> >          rowdata.append(pygame.Rect(arg
> > 1, arg2, arg3, arg4)
> >      grid.append(rowdata)
> >
> > Seems very good, but keep in mind I just started programming last week,
> and
> > this is hard for me to wrap my head around. Do I really just write grid =
> > []? or is this like a def grid(): function?
>
> This code was intended to replace the 200 lines you started, A1= pygame...
> A2=  A3=   etc.  I'd have put them inside a function, but this is just one
> of the things I'd have initialized in such a function.  grid is a list of
> lists, not a function.
>
>
> > What do you mean by rowdata = []?
>
> [] is the way you define an empty list.  Another way might be:
>     rowdata = list()
>
>
> > And how exactly would I make the formula for a rect call?
>
> Well, for row==0 and col==0, you say you wanted 10, 12, 43, and 43 for the
> four parameters.   But you never said how you were going to (manually)
> calculate those numbers for other cells.  Only once you've decided that can
> you fill in "formulas" for arg1 and arg2.  I suspect that arg3 and arg4 are
> simply 43 and 43 respectively, since you want all the cells to be the same
> size.
>
> taking my clue from Ian, I might try:
>
>     x_offset = 10
>     y_offset = 12
>     width = height = 43
>     arg1 = column * width + x_offset
>     arg2 = row * height + y_offset
>     arg3 = width
>     arg4 = height
>
> That assumes that there is no gap between cells in this grid.  If you want
> a gap, then the width value used in the arg1 formula would be more than 43
> (width).  Likewise the height value used in the arg2 formula would be more
> than 43 (height).
>
> > If there's a good website for these kind of details, I would appreciate
> that too.
>
> You cannot begin to write a non-trivial program in Python without
> understanding lists pretty thoroughly.  Perhaps you should start with Alan
> Gauld's tutorial, which doesn't assume previous programming experience.
>    http://www.alan-g.me.uk/
>
> I haven't studied it, as Python was about my 35th programming language.
>  But he's very active on Python-tutor, and explains things very well. So
> his website is probably very good as well.
>
> Now, as you can see from Ian's message, writing a game using pygame will
> require quite a bit of other understanding.  He demonstrates with classes
> to represent cells, which is indeed what I'd do.  But I suspect you're not
> nearly ready to consider writing classes.  (You use classes all the time.
>  For example, 5 is an instance of class int.)
>
>
> --
> DaveA
>
>
>
> --
> DaveA
> --
> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>
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From abradley201 at gmail.com  Wed May 15 18:48:07 2013
From: abradley201 at gmail.com (Andrew Bradley)
Date: Wed, 15 May 2013 18:48:07 -0400
Subject: Question re: objects and square grids
In-Reply-To: <CAPp_YbVBm2444Ea-pUy2Zn2YbB1mKmDoasmNXp7DPAbs8Sra4g@mail.gmail.com>
References: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
	<5193CC16.80304@davea.name> <5193E8C0.1060004@davea.name>
	<CAPp_YbVBm2444Ea-pUy2Zn2YbB1mKmDoasmNXp7DPAbs8Sra4g@mail.gmail.com>
Message-ID: <CAPp_YbVk4NwSxSpVEASCk0w=1mPoRii+RjccnXNLP+8igf3H2g@mail.gmail.com>

ok, now I have tested this more thoroughly, and it seems i can only do the
grid[x][y] function up to grid[9][9], when i really should be able to be
doing up to grid[10][20].
What exactly is the function of this row_squares list?



On Wed, May 15, 2013 at 4:35 PM, Andrew Bradley <abradley201 at gmail.com>wrote:

> Now I want to show you what I have written:
>
> row = (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
> column = (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
> 18, 19, 20)
> SQUARESIZE = 43
>
> grid = []
> for row in range(10):
>     row_squares = []
>     for column in range(20):
>         rect = Rect(12 + column * SQUARESIZE, 10 + row * SQUARESIZE,
> SQUARESIZE, SQUARESIZE)
>         row_squares.append(rect)
>     grid.append(row_squares)
>
> It appears to be working (that is, the program still runs without
> crashing). So now, how can I utilize this new grid list? Thank you for the
> help so far, I feel like the entire grid is now being worked out.
> -Andrew
>
>
>
> On Wed, May 15, 2013 at 3:57 PM, Dave Angel <davea at davea.name> wrote:
>
>> On 05/15/2013 02:14 PM, Andrew Bradley wrote:
>>
>> Please reply on the list, not privately, unless it's something like a
>> simple thank-you.  Typically, you'd do a reply-all, then delete the people
>> other than the list itself.  Or if you're using Thunderbird, you could just
>> reply-list.
>>
>> > Thank you very much for your response: it seems excellent, but I'm
>> afraid I
>> > do not understand it fully. Your code here:
>>
>> >
>> > maxrows = 10
>> > maxcols = 20
>> > grid = []
>> > for row in range(maxrows):
>> >      rowdata = []
>> >      for column in range(maxcols):
>> >          arg1 = ...
>> >          arg2 = ...
>> >          arg3 = ...
>> >          arg4 = ...
>> >          rowdata.append(pygame.Rect(arg
>> > 1, arg2, arg3, arg4)
>> >      grid.append(rowdata)
>> >
>> > Seems very good, but keep in mind I just started programming last week,
>> and
>> > this is hard for me to wrap my head around. Do I really just write grid
>> =
>> > []? or is this like a def grid(): function?
>>
>> This code was intended to replace the 200 lines you started, A1=
>> pygame... A2=  A3=   etc.  I'd have put them inside a function, but this is
>> just one of the things I'd have initialized in such a function.  grid is a
>> list of lists, not a function.
>>
>>
>> > What do you mean by rowdata = []?
>>
>> [] is the way you define an empty list.  Another way might be:
>>     rowdata = list()
>>
>>
>> > And how exactly would I make the formula for a rect call?
>>
>> Well, for row==0 and col==0, you say you wanted 10, 12, 43, and 43 for
>> the four parameters.   But you never said how you were going to (manually)
>> calculate those numbers for other cells.  Only once you've decided that can
>> you fill in "formulas" for arg1 and arg2.  I suspect that arg3 and arg4 are
>> simply 43 and 43 respectively, since you want all the cells to be the same
>> size.
>>
>> taking my clue from Ian, I might try:
>>
>>     x_offset = 10
>>     y_offset = 12
>>     width = height = 43
>>     arg1 = column * width + x_offset
>>     arg2 = row * height + y_offset
>>     arg3 = width
>>     arg4 = height
>>
>> That assumes that there is no gap between cells in this grid.  If you
>> want a gap, then the width value used in the arg1 formula would be more
>> than 43 (width).  Likewise the height value used in the arg2 formula would
>> be more than 43 (height).
>>
>> > If there's a good website for these kind of details, I would appreciate
>> that too.
>>
>> You cannot begin to write a non-trivial program in Python without
>> understanding lists pretty thoroughly.  Perhaps you should start with Alan
>> Gauld's tutorial, which doesn't assume previous programming experience.
>>    http://www.alan-g.me.uk/
>>
>> I haven't studied it, as Python was about my 35th programming language.
>>  But he's very active on Python-tutor, and explains things very well. So
>> his website is probably very good as well.
>>
>> Now, as you can see from Ian's message, writing a game using pygame will
>> require quite a bit of other understanding.  He demonstrates with classes
>> to represent cells, which is indeed what I'd do.  But I suspect you're not
>> nearly ready to consider writing classes.  (You use classes all the time.
>>  For example, 5 is an instance of class int.)
>>
>>
>> --
>> DaveA
>>
>>
>>
>> --
>> DaveA
>> --
>> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>>
>
>
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From davea at davea.name  Wed May 15 20:17:48 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 15 May 2013 20:17:48 -0400
Subject: Question re: objects and square grids
In-Reply-To: <CAPp_YbVk4NwSxSpVEASCk0w=1mPoRii+RjccnXNLP+8igf3H2g@mail.gmail.com>
References: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
	<5193CC16.80304@davea.name> <5193E8C0.1060004@davea.name>
	<CAPp_YbVBm2444Ea-pUy2Zn2YbB1mKmDoasmNXp7DPAbs8Sra4g@mail.gmail.com>
	<CAPp_YbVk4NwSxSpVEASCk0w=1mPoRii+RjccnXNLP+8igf3H2g@mail.gmail.com>
Message-ID: <519425AC.3070605@davea.name>

Please put new comments AFTER the part you're quoting.  In other words, 
don't top-post.  Also please trim off the stuff that's no longer 
relevant, so people don't have to read through it all wondering where 
your implied comments are.

On 05/15/2013 06:48 PM, Andrew Bradley wrote:
> ok, now I have tested this more thoroughly, and it seems i can only do the
> grid[x][y] function up to grid[9][9], when i really should be able to be
> doing up to grid[10][20].

No, you shouldn't expect it to go to 10,20.  Remember I said that Python 
is zero-based.  So it goes from 0 to 9 inclusive, and from 0 to 19 
inclusive.  Upper left corner is grid[0][0], while lower right is 
grid[9][19].  Check to make sure that range works, which I think it will.


> What exactly is the function of this row_squares list?

It's a temporary to hold one row.  You could delete it after the outer 
loop ends, if you like. Normally, if this whole thing were inside a 
function, the variable would go away when the function ended, and you'd 
be returning the grid list only.

You could have avoided the separate name by doing some tricky syntax. 
But I'm trying to show you the clearest way of doing things from a 
beginner perspective.

>
>
>
> On Wed, May 15, 2013 at 4:35 PM, Andrew Bradley <abradley201 at gmail.com>wrote:
>
>> Now I want to show you what I have written:
>>
>> row = (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
>> column = (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
>> 18, 19, 20)

No point in initializing them to tuples, since you're not going to use 
those.  Besides, in a moment row and column become ints, and this just 
confuses things.  The range() function below builds a temporary list 
which looks just like what you tediously typed in (except it's square 
brackets instead of round).

>> SQUARESIZE = 43
>>
>> grid = []
>> for row in range(10):
>>      row_squares = []
>>      for column in range(20):
>>          rect = Rect(12 + column * SQUARESIZE, 10 + row * SQUARESIZE,
>> SQUARESIZE, SQUARESIZE)
>>          row_squares.append(rect)
>>      grid.append(row_squares)
>>
>> It appears to be working (that is, the program still runs without
>> crashing).

Sorry, but that's no criteria.  Question is whether it's doing what you 
want.  Are the rows 20 across and are there 10 of them?  Do the values 
of each individual rect look right?  print is your friend.

>> So now, how can I utilize this new grid list? Thank you for the
>> help so far, I feel like the entire grid is now being worked out.
>> -Andrew
>>

That's a Pygame question, and I told you at the beginning, I can't 
really help with that.  I'd like to learn, but not this week.

Others - can you show some minimal code to use these grid parameters to 
color selected squares of the pygame window?

-- 
DaveA


From abradley201 at gmail.com  Wed May 15 20:53:05 2013
From: abradley201 at gmail.com (Andrew Bradley)
Date: Wed, 15 May 2013 20:53:05 -0400
Subject: Question re: objects and square grids
In-Reply-To: <519425AC.3070605@davea.name>
References: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
	<5193CC16.80304@davea.name> <5193E8C0.1060004@davea.name>
	<CAPp_YbVBm2444Ea-pUy2Zn2YbB1mKmDoasmNXp7DPAbs8Sra4g@mail.gmail.com>
	<CAPp_YbVk4NwSxSpVEASCk0w=1mPoRii+RjccnXNLP+8igf3H2g@mail.gmail.com>
	<519425AC.3070605@davea.name>
Message-ID: <CAPp_YbWPP-ptEuhnsqt7SvmBB2Ft_5XpiTV1dARMe9Ef=eYwhQ@mail.gmail.com>

>
>
>  SQUARESIZE = 43
>>>
>>> grid = []
>>> for row in range(10):
>>>      row_squares = []
>>>      for column in range(20):
>>>          rect = Rect(12 + column * SQUARESIZE, 10 + row * SQUARESIZE,
>>> SQUARESIZE, SQUARESIZE)
>>>          row_squares.append(rect)
>>>      grid.append(row_squares)
>>>
>>> It appears to be working (that is, the program still runs without
>>> crashing).
>>>
>>
> Sorry, but that's no criteria.  Question is whether it's doing what you
> want.  Are the rows 20 across and are there 10 of them?  Do the values of
> each individual rect look right?  print is your friend.


Yes, I have gotten rid of that part with the 1, 2, 3, 4, etc., and now the
code appears to be working up to [9][19]. Thank you very much. The
coordinates all do look correct, and there are 200 rectangles when I do
list(grid).

>
>
>  So now, how can I utilize this new grid list? Thank you for the
>>> help so far, I feel like the entire grid is now being worked out.
>>> -Andrew
>>>
>>>
> That's a Pygame question, and I told you at the beginning, I can't really
> help with that.  I'd like to learn, but not this week.
>
> Others - can you show some minimal code to use these grid parameters to
> color selected squares of the pygame window?
>
>
Yes, I would very much like some help or general advice now about utilizing
this grid thing. How can I refer to these square's new numerical values to
do things with them? Will I be using things like "grid[0][1]" in specific
functions and methods to refer to squares now? That is what I would like to
do, somehow.

>
> --
> DaveA
> --
> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>

I apologize if these questions are too rudimentary--I am trying to wrap my
head around how this language works in a more general sense so I can start
applying it to things.
-Andrew
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From davea at davea.name  Wed May 15 21:20:31 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 15 May 2013 21:20:31 -0400
Subject: Question re: objects and square grids
In-Reply-To: <CAPp_YbWPP-ptEuhnsqt7SvmBB2Ft_5XpiTV1dARMe9Ef=eYwhQ@mail.gmail.com>
References: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
	<5193CC16.80304@davea.name> <5193E8C0.1060004@davea.name>
	<CAPp_YbVBm2444Ea-pUy2Zn2YbB1mKmDoasmNXp7DPAbs8Sra4g@mail.gmail.com>
	<CAPp_YbVk4NwSxSpVEASCk0w=1mPoRii+RjccnXNLP+8igf3H2g@mail.gmail.com>
	<519425AC.3070605@davea.name>
	<CAPp_YbWPP-ptEuhnsqt7SvmBB2Ft_5XpiTV1dARMe9Ef=eYwhQ@mail.gmail.com>
Message-ID: <5194345F.9070209@davea.name>

On 05/15/2013 08:53 PM, Andrew Bradley wrote:
>>
>>
>>   <SNIP>
>>
>>   So now, how can I utilize this new grid list? Thank you for the
>>>> help so far, I feel like the entire grid is now being worked out.
>>>> -Andrew
>>>>
>>>>
>> That's a Pygame question, and I told you at the beginning, I can't really
>> help with that.  I'd like to learn, but not this week.
>>
>> Others - can you show some minimal code to use these grid parameters to
>> color selected squares of the pygame window?
>>
>>
> Yes, I would very much like some help or general advice now about utilizing
> this grid thing. How can I refer to these square's new numerical values to
> do things with them? Will I be using things like "grid[0][1]" in specific
> functions and methods to refer to squares now?

Yes, exactly.  Any place in your code (the part I cannot help with) that 
you need to specify a rect, you can specify something like grid[3][18]. 
  Eventually, as Ian pointed out, you'll want to store more information 
about each cell.  But at that time, you could have a more complex object 
(that YOU define) instead of just a rect.  I just don't think you're 
ready for defining such an object.

> That is what I would like to
> do, somehow.
>



-- 
DaveA


From orgnut at yahoo.com  Thu May 16 02:54:37 2013
From: orgnut at yahoo.com (Larry Hudson)
Date: Wed, 15 May 2013 23:54:37 -0700
Subject: Question re: objects and square grids
In-Reply-To: <mailman.1727.1368665595.3114.python-list@python.org>
References: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
	<5193CC16.80304@davea.name> <5193E8C0.1060004@davea.name>
	<CAPp_YbVBm2444Ea-pUy2Zn2YbB1mKmDoasmNXp7DPAbs8Sra4g@mail.gmail.com>
	<CAPp_YbVk4NwSxSpVEASCk0w=1mPoRii+RjccnXNLP+8igf3H2g@mail.gmail.com>
	<519425AC.3070605@davea.name>
	<mailman.1727.1368665595.3114.python-list@python.org>
Message-ID: <TaqdnfITWvAzHwnMnZ2dnUVZ_uOdnZ2d@giganews.com>

On 05/15/2013 05:53 PM, Andrew Bradley wrote:
<snip>

> I apologize if these questions are too rudimentary--I am trying to wrap my head around how this
> language works in a more general sense so I can start applying it to things.
> -Andrew

Check out the book "Making Games with Python & Pygame" at http://inventwithpython.com/pygame/
It's a book you can buy or you can download the pdf or e-reader versions for free.

Also on the same site, "Invent Your Own Computer Games with Python"

Both are pretty good introductions to Python programming, "Invent..." is for non-graphic games, 
and may be the better to start with.  Don't try to get too advanced too fast -- you'll only get 
frustrated and discouraged.  But definitely do keep at it -- it's well worth the effort.

      -=- Larry -=-



From ian.g.kelly at gmail.com  Wed May 15 14:01:06 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 15 May 2013 12:01:06 -0600
Subject: Question re: objects and square grids
In-Reply-To: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
References: <CAPp_YbVwiK1RBk_fLP32Kzv56GjYUf4TL=Ogzo5qsOKtrd8kGg@mail.gmail.com>
Message-ID: <CALwzidn2YbagcDGUvcveS=A0g4mNeRwKR+wN2ynKfnQrrCojOw@mail.gmail.com>

On Wed, May 15, 2013 at 10:56 AM, Andrew Bradley <abradley201 at gmail.com> wrote:
> Hello everyone.
>
> I am having a good time programming with Python 3.3 and Pygame. Pygame seems
> like the perfect platform for the kind of simple games that I want to make.
>
> What I have currently programmed is basically a drawn rectangle filled with
> 200 squares, each side of the squares being 43 pixels. The rectangle is 20
> squares by 10 squares.

It's more work, but I would recommend making the squares scalable in
some manner, instead of arbitrarily hard-coding them at 43 pixels.
What are you going to do when somebody has a 4K monitor and wants to
run the game full screen?

> This grid is what I want to have the entire game on. There will be pieces
> that move certain numbers of squares, perform actions that effect pieces on
> certain squares, etc. The possibilities are endless.
>
> So what I am now trying to do is organize these squares into objects that I
> can easily reference when programming things related to the squares.
>
> So far, I have done this:
>
> A1 = pygame.Rect(10, 12, 43, 43)
> A2
> A3
> A4
> B1
> B2
> etc.

This is a tedious, repetitive, and error-prone way to build all the
squares.  Instead of having a separate variable for each square,
consider putting them in a collection and building them up using
nested loops.  For example, the above could look something like:

squares = []
for row in range(10):
    row_squares = []
    for column in range(20):
        rect = Rect(column * width + x_offset, row * height + y_offset,
                    width, height)
        row_squares.append(rect)
    squares.append(row_squares)

Then the A1 rect is accessible as squares[0][0], A2 as squares[0][1],
B1 as squares[1][0], etc.  Alternatively, you could store the rects in
a dict and use "A1", "B1", etc. as the keys, but I think you will find
that the game logic will be simpler if you use integers internally for
your rows and columns, rather than the square labels.

> where said integers are the precise location of the top left-most square for
> A1, and onward down the line. I would guess that I could continue on in such
> a fashion, with appropriate box names for each square. But I'm running into
> the problem of confirming that the code above actually does something
> useful. For example, I would love to be able to turn A1 a different color,
> but how does this work? How do I actually utilize these object variable
> names? Are there methods that I am not aware of, because most things I try
> tend to do nothing or crash the game. For example, A1.fill(BLUE) does not
> work.

A Rect only stores position and size information and provides methods
for processing the same.  It doesn't know anything about drawing.  Use
the pygame.draw or pygame.gfxdraw functions for that.  For example, to
fill a part of the screen as indicated by the position of a rect:

BLUE = (0, 0, 255)
pygame.draw.rect(screen, BLUE, squares[0][0])

That said, you probably don't just want to color a square blue.  You
probably also want to remember that the square is blue for when you
are redrawing it later.  You need to track not just the position of
each square, but also their state.  This means that each object in
your "squares" container should not just be a rect, but some broader
object that contains square data, *including* a rect.  Something like
this:

class Square:

    def __init__(self, rect):
        self.rect = rect
        self.color = (0, 0, 0)
        self.contents = None
        # ... and whatever else you need to track

Then when you fill the squares container, you would fill it with
instances of your Square class instead of plain Rects, which gives you
a place to keep track of the square's color, among other things.  The
drawing code above then might look something like this:

pygame.draw.rect(screen, some_square.color, some_square.rect)


From susheel.ssoft at gmail.com  Wed May 15 16:41:30 2013
From: susheel.ssoft at gmail.com (susheel kumar)
Date: Wed, 15 May 2013 13:41:30 -0700 (PDT)
Subject: Immediate Position:::Business Analyst With BI EXP::::At Houston, TX
Message-ID: <7f49d11b-2f0e-4240-93e8-ead55c5ed4dc@yb1g2000pbc.googlegroups.com>

Hi,

This is Girish, - Recruitment and Resources from SancroSoft USA Inc.

We have an urgent requirement as follows:

Please respond with resumes in MS-Word Format with the following
details toGirish at sancrosoftusa.com

Full Name :
Location :
Contact Number :
Email :
Availability :
Visa Status :
Business Analyst & Data Analyst

Location: Houston, TX
Duration: 12 Months
Rate: Market

Job Description:

?              Total IT experience - 8-10 / 2-3 years as Business /
Data Analyst
?              Plan Requirement Gathering and Business Analysis
efforts
?         Liaise with Business and IT teams to coordinate
interdependencies and resolve issues
?         Interact with SMEs on functional needs to Gather & Analyze
the requirements
?         Outline Operational Process and Identify any shortages in
terms of process or documentation
?         Source System Data Analysis & Issue resolution
?         Developing and maintaining technical documentation about the
data
?         Conduct reviews and provide assistance to BA team members in
system documentation
?         Co-ordination with technical team to resolve any data
related issues like date quality, data integrity
?         Coordinates and conduct user acceptance testing.
?         Facilitating end user training
?              Financial domain experience (Accounting, GL, AR, AP
etc) would be preferred
?              Experience in BI/DWH domain would be a plus
?              Excellent verbal and written communication
?              The candidate should be proactive, self motivated and
resourceful
?              Excellent interpersonal skills with an ability to build
effective relationships
?              Strong knowledge of all Microsoft Office tools
?              Excellent time management skills and working experience
on-shore/off-shore model

Thanks & Regards,
Girish
 IT Recruiter.


 The power of focus
SancroSoft USA INC
4944 Sunrise Blvd, Suite B-4 || Fair Oaks, CA 95628
Phone : 916-671-5591|| Fax: 916-200-0305
E-Mail : girish at sancrosoftusa.com  www.sancrosoftusa.com


From susheel.ssoft at gmail.com  Wed May 15 16:42:49 2013
From: susheel.ssoft at gmail.com (susheel kumar)
Date: Wed, 15 May 2013 13:42:49 -0700 (PDT)
Subject: Immediate Position:::Business Analyst With BI EXP::::At Houston, TX
Message-ID: <75e3d5e6-3174-41b4-b3b9-3e056ac98a56@ve4g2000pbb.googlegroups.com>

Hi,

This is Girish, - Recruitment and Resources from SancroSoft USA Inc.

We have an urgent requirement as follows:

Please respond with resumes in MS-Word Format with the following
details toGirish at sancrosoftusa.com

Full Name :
Location :
Contact Number :
Email :
Availability :
Visa Status :
Business Analyst & Data Analyst

Location: Houston, TX
Duration: 12 Months
Rate: Market

Job Description:

?              Total IT experience - 8-10 / 2-3 years as Business /
Data Analyst
?              Plan Requirement Gathering and Business Analysis
efforts
?         Liaise with Business and IT teams to coordinate
interdependencies and resolve issues
?         Interact with SMEs on functional needs to Gather & Analyze
the requirements
?         Outline Operational Process and Identify any shortages in
terms of process or documentation
?         Source System Data Analysis & Issue resolution
?         Developing and maintaining technical documentation about the
data
?         Conduct reviews and provide assistance to BA team members in
system documentation
?         Co-ordination with technical team to resolve any data
related issues like date quality, data integrity
?         Coordinates and conduct user acceptance testing.
?         Facilitating end user training
?              Financial domain experience (Accounting, GL, AR, AP
etc) would be preferred
?              Experience in BI/DWH domain would be a plus
?              Excellent verbal and written communication
?              The candidate should be proactive, self motivated and
resourceful
?              Excellent interpersonal skills with an ability to build
effective relationships
?              Strong knowledge of all Microsoft Office tools
?              Excellent time management skills and working experience
on-shore/off-shore model

Thanks & Regards,
Girish
 IT Recruiter.


 The power of focus
SancroSoft USA INC
4944 Sunrise Blvd, Suite B-4 || Fair Oaks, CA 95628
Phone : 916-671-5591|| Fax: 916-200-0305
E-Mail : girish at sancrosoftusa.com  www.sancrosoftusa.com


From halagamal2009 at gmail.com  Wed May 15 18:00:36 2013
From: halagamal2009 at gmail.com (Hala Gamal)
Date: Wed, 15 May 2013 15:00:36 -0700 (PDT)
Subject: Translation API in Python
Message-ID: <baff2d6f-272a-479e-8f78-2aafb74e6a5d@googlegroups.com>

I want to use A translator from Arabic to English and reverse in my application which is written in pyhton,
Is there  any open source Translator that can be used with python,
Or Any Suggestion?
Please Help,
Thanks In Advance :)


From rosuav at gmail.com  Wed May 15 20:02:13 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 16 May 2013 10:02:13 +1000
Subject: Translation API in Python
In-Reply-To: <baff2d6f-272a-479e-8f78-2aafb74e6a5d@googlegroups.com>
References: <baff2d6f-272a-479e-8f78-2aafb74e6a5d@googlegroups.com>
Message-ID: <CAPTjJmqqTuna9QGxtqTBY9BEPVap7_P2tPYetMU8D=QydtujNg@mail.gmail.com>

On Thu, May 16, 2013 at 8:00 AM, Hala Gamal <halagamal2009 at gmail.com> wrote:
> I want to use A translator from Arabic to English and reverse in my application which is written in pyhton,
> Is there  any open source Translator that can be used with python,
> Or Any Suggestion?
> Please Help,
> Thanks In Advance :)

I would recommend, in order:
1) Searching the Python modules [1]
2) Searching PyPI [2]
3) Searching the web [3]
4) Finding a translation program that uses stdin/stdout

I suspect #1 will come up blank, but any of the others could well come
up with something. Working with an external program is a bit harder
than an actual Python module, but it'll work.

ChrisA
[1] http://docs.python.org/3/
[2] https://pypi.python.org/pypi
[3] http://www.google.com/ or http://www.duckduckgo.com/ or
http://yahoo.com/ or whatever


From halagamal2009 at gmail.com  Tue May 21 18:16:40 2013
From: halagamal2009 at gmail.com (Hala Gamal)
Date: Tue, 21 May 2013 15:16:40 -0700 (PDT)
Subject: Translation API in Python
In-Reply-To: <mailman.1723.1368662535.3114.python-list@python.org>
References: <baff2d6f-272a-479e-8f78-2aafb74e6a5d@googlegroups.com>
	<mailman.1723.1368662535.3114.python-list@python.org>
Message-ID: <b8e54d77-cc20-4724-885e-3e81de629d03@googlegroups.com>

ok MR,
I have searched before asking here,but i didn't find thing


From rosuav at gmail.com  Wed May 22 10:27:29 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 00:27:29 +1000
Subject: Translation API in Python
In-Reply-To: <b8e54d77-cc20-4724-885e-3e81de629d03@googlegroups.com>
References: <baff2d6f-272a-479e-8f78-2aafb74e6a5d@googlegroups.com>
	<mailman.1723.1368662535.3114.python-list@python.org>
	<b8e54d77-cc20-4724-885e-3e81de629d03@googlegroups.com>
Message-ID: <CAPTjJmo5Y3g9sOjcW+y5ktHC03dEPCeUB1WsRA_FnpD9OOXNFA@mail.gmail.com>

On Wed, May 22, 2013 at 8:16 AM, Hala Gamal <halagamal2009 at gmail.com> wrote:
> ok MR,
> I have searched before asking here,but i didn't find thing

Your post doesn't demonstrate that. When you ask a question like this,
it's helpful to give at least some indication of what you've tried and
what you haven't. Also, I strongly suspect that #4 is going to turn
something up; though of course people who read this post now have no
idea what I'm talking about, because you're responding to last week's
post without a shred of context.

Here are some tips that might help you:

http://www.catb.org/esr/faqs/smart-questions.html

ChrisA
PS. I say "might" only because they can't help if they're not followed.


From miller.eric.t at gmail.com  Wed May 15 21:47:06 2013
From: miller.eric.t at gmail.com (Eric Miller)
Date: Wed, 15 May 2013 18:47:06 -0700 (PDT)
Subject: python sockets question
Message-ID: <6aa0447a-e6eb-47b7-9444-71922dad82e7@googlegroups.com>

Can python sockets be used to capture IP traffic when the traffic is originating from a non-python source?

Using a Lantronix UDS-1100 serial to IP converter. The goal is to write a small proof of concept piece in Python to capture serial data output by this device over IP.

I've done a couple test projects using sockets in python, but they were all done between python processes (python > python): listen() on one end, and connect(), sendall() etc on the other.

I think I can use sockets for this project, but before I invest a bunch of time into it, wanted to make sure it is a viable solution.

Can python sockets be used to capture IP traffic when the traffic is originating from a non-python source? I have full control over the IP and port that the device sends the serial data to, but there will be no python connect() initiated by the client. I can pre-pend then serial data with some connect() string if needed.

If sockets won't work, please recommend another solution...guessing it will be REST or similar.


From bahamutzero8825 at gmail.com  Wed May 15 22:28:17 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Wed, 15 May 2013 21:28:17 -0500
Subject: python sockets question
In-Reply-To: <6aa0447a-e6eb-47b7-9444-71922dad82e7@googlegroups.com>
References: <6aa0447a-e6eb-47b7-9444-71922dad82e7@googlegroups.com>
Message-ID: <51944441.2050309@gmail.com>

On 2013.05.15 20:47, Eric Miller wrote:
> Can python sockets be used to capture IP traffic when the traffic is originating from a non-python source?
Python just exposes the underlying OS socket interface. There is nothing special about sockets in Python. The whole point is to connect
heterogeneous systems. I can use Python on Windows to create a client that will connect to a service written in C running on Solaris or to
something written in Java running on Linux.

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From benjamin at python.org  Thu May 16 00:19:06 2013
From: benjamin at python.org (Benjamin Peterson)
Date: Wed, 15 May 2013 23:19:06 -0500
Subject: [RELEASED] Python 2.7.5
Message-ID: <CAPZV6o-ryi7gijo32s0jbOTKskpntTRVcpUk5XJfqP_hZRW9qg@mail.gmail.com>

It is my greatest pleasure to announce the release of Python 2.7.5.

2.7.5 is the latest maintenance release in the Python 2.7 series. You may be
surprised to hear from me so soon, as Python 2.7.4 was released slightly more
than a month ago. As it turns out, 2.7.4 had several regressions and
incompatibilities with 2.7.3. Among them were regressions in the zipfile, gzip,
and logging modules. 2.7.5 fixes these. In addition, a data file for testing in
the 2.7.4 tarballs and binaries aroused the suspicion of some virus
checkers. The 2.7.5 release removes this file to resolve that issue.

For details, see the Misc/NEWS file in the distribution or view it at

    http://hg.python.org/cpython/file/ab05e7dd2788/Misc/NEWS

Downloads are at

    http://python.org/download/releases/2.7.5/

As always, please report bugs to

    http://bugs.python.org/

(Thank you to those who reported these bugs in 2.7.4.)

This is a production release.

Happy May,
Benjamin Peterson
2.7 Release Manager
(on behalf of all of Python 2.7's contributors)


From carlosnepomuceno at outlook.com  Thu May 16 00:48:09 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 16 May 2013 07:48:09 +0300
Subject: [RELEASED] Python 2.7.5
In-Reply-To: <CAPZV6o-ryi7gijo32s0jbOTKskpntTRVcpUk5XJfqP_hZRW9qg@mail.gmail.com>
References: <CAPZV6o-ryi7gijo32s0jbOTKskpntTRVcpUk5XJfqP_hZRW9qg@mail.gmail.com>
Message-ID: <BLU176-W28C7E28B1248442DABF1ACD7A30@phx.gbl>

test_asynchat still hangs! What it does? Should I care?

----------------------------------------
> Date: Wed, 15 May 2013 23:19:06 -0500
> Subject: [RELEASED] Python 2.7.5
> From: benjamin at python.org
> To: python-dev at python.org; python-list at python.org; python-announce-list at python.org
>
> It is my greatest pleasure to announce the release of Python 2.7.5.
>
> 2.7.5 is the latest maintenance release in the Python 2.7 series. You may be
> surprised to hear from me so soon, as Python 2.7.4 was released slightly more
> than a month ago. As it turns out, 2.7.4 had several regressions and
> incompatibilities with 2.7.3. Among them were regressions in the zipfile, gzip,
> and logging modules. 2.7.5 fixes these. In addition, a data file for testing in
> the 2.7.4 tarballs and binaries aroused the suspicion of some virus
> checkers. The 2.7.5 release removes this file to resolve that issue.
>
> For details, see the Misc/NEWS file in the distribution or view it at
>
> http://hg.python.org/cpython/file/ab05e7dd2788/Misc/NEWS
>
> Downloads are at
>
> http://python.org/download/releases/2.7.5/
>
> As always, please report bugs to
>
> http://bugs.python.org/
>
> (Thank you to those who reported these bugs in 2.7.4.)
>
> This is a production release.
>
> Happy May,
> Benjamin Peterson
> 2.7 Release Manager
> (on behalf of all of Python 2.7's contributors)
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From georg at python.org  Thu May 16 01:20:30 2013
From: georg at python.org (Georg Brandl)
Date: Thu, 16 May 2013 07:20:30 +0200
Subject: [RELEASED] Python 3.2.5 and Python 3.3.2
Message-ID: <51946C9E.10607@python.org>

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On behalf of the Python development team, I am pleased to announce the
releases of Python 3.2.5 and 3.3.2.

The releases fix a few regressions in 3.2.4 and 3.3.1 in the zipfile, gzip
and xml.sax modules.  Details can be found in the changelogs:

    http://hg.python.org/cpython/file/v3.2.5/Misc/NEWS  and
    http://hg.python.org/cpython/file/v3.3.2/Misc/NEWS

To download Python 3.2.5 or Python 3.3.2, visit:

    http://www.python.org/download/releases/3.2.5/  or
    http://www.python.org/download/releases/3.3.2/

respectively.  As always, please report bugs to

    http://bugs.python.org/

(Thank you to those who reported these regressions.)

Enjoy!

- -- 
Georg Brandl, Release Manager
georg at python.org
(on behalf of the entire python-dev team and all contributors)
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)

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EjgAoIWAOFNhJNdTAWEGSWqFWUP20wrb
=YnPr
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From steve+comp.lang.python at pearwood.info  Thu May 16 01:22:38 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 16 May 2013 05:22:38 GMT
Subject: Generating multi-part emails
Message-ID: <51946d1e$0$29978$c3e8da3$5496439d@news.astraweb.com>

I wish to generate some test data for a program that deals with emails. I 
need something that can produce multi-part emails, including "broken" 
emails that violate email standards, especially when it comes to Unicode.

Does anyone know of something like this that already exists? It's not 
necessary for the package to actually send the emails, dumping them into 
an mbox is sufficient.


-- 
Steven


From dieter at handshake.de  Thu May 16 02:01:55 2013
From: dieter at handshake.de (dieter)
Date: Thu, 16 May 2013 08:01:55 +0200
Subject: Generating multi-part emails
References: <51946d1e$0$29978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87a9nvtqcs.fsf@handshake.de>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:

> I wish to generate some test data for a program that deals with emails. I 
> need something that can produce multi-part emails, including "broken" 
> emails that violate email standards, especially when it comes to Unicode.

I would start producing legal messages (e.g. with the "email"
package) and then put in common standard violations.

I am using the XEmacs "vm" email package and it has
difficulties with the quoting of non-ascii characters
in header lines (it performes the quoting based on non-ascii
character sequences rather than on words, as it should).


Maybe, there is an email message catalog around for the test
of email servers/clients. I would check for this in corresponding
open source projects.



From cts.private.yahoo at gmail.com  Thu May 16 03:48:45 2013
From: cts.private.yahoo at gmail.com (Charles Smith)
Date: Thu, 16 May 2013 00:48:45 -0700 (PDT)
Subject: executing python scripts that are symlinked
Message-ID: <95bc1155-0a83-4ab1-8b76-68a819b2e29a@en2g2000vbb.googlegroups.com>

Hi.

How can I say, from the cmd line, that python should take my CWD as my
CWD, and not the directory where the script actually is?


I have a python script that works fine when it sits in directory WC,
but if I move it out of WC to H and put a symlink from H/script to WC,
it doesn't find the packages that are in WC.  Also, if I use the
absolute path to H, it won't find them, but I guess I can understand
that.

Someone said on the net that python doesn't know whether a file is
real or a symlink, but I think that somehow, python is able to find
out where the real file is and treat that as its base of operations.

Charles.

----------------------------------------------------------
http://www.creative-telcom-solutions.de


From bahamutzero8825 at gmail.com  Thu May 16 04:12:50 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Thu, 16 May 2013 03:12:50 -0500
Subject: executing python scripts that are symlinked
In-Reply-To: <95bc1155-0a83-4ab1-8b76-68a819b2e29a@en2g2000vbb.googlegroups.com>
References: <95bc1155-0a83-4ab1-8b76-68a819b2e29a@en2g2000vbb.googlegroups.com>
Message-ID: <51949502.1030807@gmail.com>

On 2013.05.16 02:48, Charles Smith wrote:
> Hi.
> 
> How can I say, from the cmd line, that python should take my CWD as my
> CWD, and not the directory where the script actually is?
> 
> 
> I have a python script that works fine when it sits in directory WC,
> but if I move it out of WC to H and put a symlink from H/script to WC,
> it doesn't find the packages that are in WC.  Also, if I use the
> absolute path to H, it won't find them, but I guess I can understand
> that.
Symlinks can find their targets, but targets have absolutely no way of knowing where symlinks to them are. It's one-way. It would work if
the actual file were in WC and you created a symlink inside H.

-- 
CPython 3.3.1 | Windows NT 6.2.9200 / FreeBSD 9.1


From davea at davea.name  Thu May 16 04:18:05 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 16 May 2013 04:18:05 -0400
Subject: executing python scripts that are symlinked
In-Reply-To: <95bc1155-0a83-4ab1-8b76-68a819b2e29a@en2g2000vbb.googlegroups.com>
References: <95bc1155-0a83-4ab1-8b76-68a819b2e29a@en2g2000vbb.googlegroups.com>
Message-ID: <5194963D.1070602@davea.name>

On 05/16/2013 03:48 AM, Charles Smith wrote:
> Hi.
>
> How can I say, from the cmd line, that python should take my CWD as my
> CWD, and not the directory where the script actually is?
>
>
> I have a python script that works fine when it sits in directory WC,
> but if I move it out of WC to H and put a symlink from H/script to WC,
> it doesn't find the packages that are in WC.  Also, if I use the
> absolute path to H, it won't find them, but I guess I can understand
> that.
>
> Someone said on the net that python doesn't know whether a file is
> real or a symlink, but I think that somehow, python is able to find
> out where the real file is and treat that as its base of operations.
>

You'd really better specify your environment - exact OS and Python 
version.  symlink and cwd usually imply a Unix-type system, but cmd is a 
Windows thing.

Then give examples of what your cwd is, what string you're typing at the 
shell prompt, and what's happening.

For example windows is good at changing cwd long before the executable 
gets control, in some situations.

-- 
DaveA


From cts.private.yahoo at gmail.com  Thu May 16 04:29:54 2013
From: cts.private.yahoo at gmail.com (Charles Smith)
Date: Thu, 16 May 2013 01:29:54 -0700 (PDT)
Subject: executing python scripts that are symlinked
References: <95bc1155-0a83-4ab1-8b76-68a819b2e29a@en2g2000vbb.googlegroups.com>
	<mailman.1741.1368692298.3114.python-list@python.org>
Message-ID: <8640d5b0-5e6e-4a54-9584-6e7ffcdf1389@k3g2000vbn.googlegroups.com>

On 16 Mai, 10:18, Dave Angel <da... at davea.name> wrote:
> On 05/16/2013 03:48 AM, Charles Smith wrote:
>
> > Hi.
>
> > How can I say, from the cmd line, that python should take my CWD as my
> > CWD, and not the directory where the script actually is?
>
> > I have a python script that works fine when it sits in directory WC,
> > but if I move it out of WC to H and put a symlink from H/script to WC,
> > it doesn't find the packages that are in WC. ?Also, if I use the
> > absolute path to H, it won't find them, but I guess I can understand
> > that.
>
> > Someone said on the net that python doesn't know whether a file is
> > real or a symlink, but I think that somehow, python is able to find
> > out where the real file is and treat that as its base of operations.
>
> You'd really better specify your environment - exact OS and Python
> version. ?symlink and cwd usually imply a Unix-type system, but cmd is a
> Windows thing.
>
> Then give examples of what your cwd is, what string you're typing at the
> shell prompt, and what's happening.


Well, I'm on a ubuntu platform, running subversion, but I can't commit
this debugging tool into the working copy where I'm using it, so I
maintain it in my home directory.  The tool does use production
packages, though.

So, if I say,

  $ python fapi-test.py

and fapi-test.py really is there, then it works, using the codec
production package.  But if I use a symlink instead, it says

Traceback (most recent call last):
  File "test2", line 1, in <module>
    from codec.support import *
ImportError: No module named codec.support


Python tells me Python 2.6.5 (r265:79063, Apr 16 2010, 13:09:56)



----------------------------------------------------------
http://www.creative-telcom-solutions.de



From davea at davea.name  Thu May 16 10:45:21 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 16 May 2013 10:45:21 -0400
Subject: executing python scripts that are symlinked
In-Reply-To: <8640d5b0-5e6e-4a54-9584-6e7ffcdf1389@k3g2000vbn.googlegroups.com>
References: <95bc1155-0a83-4ab1-8b76-68a819b2e29a@en2g2000vbb.googlegroups.com>
	<mailman.1741.1368692298.3114.python-list@python.org>
	<8640d5b0-5e6e-4a54-9584-6e7ffcdf1389@k3g2000vbn.googlegroups.com>
Message-ID: <5194F101.3000601@davea.name>

On 05/16/2013 04:29 AM, Charles Smith wrote:
> On 16 Mai, 10:18, Dave Angel <da... at davea.name> wrote:
>> On 05/16/2013 03:48 AM, Charles Smith wrote:
>>
>>> Hi.
>>
>>> How can I say, from the cmd line, that python should take my CWD as my
>>> CWD, and not the directory where the script actually is?
>>
>>> I have a python script that works fine when it sits in directory WC,
>>> but if I move it out of WC to H and put a symlink from H/script to WC,
>>> it doesn't find the packages that are in WC.  Also, if I use the
>>> absolute path to H, it won't find them, but I guess I can understand
>>> that.
>>
>>> Someone said on the net that python doesn't know whether a file is
>>> real or a symlink, but I think that somehow, python is able to find
>>> out where the real file is and treat that as its base of operations.
>>
>> You'd really better specify your environment - exact OS and Python
>> version.  symlink and cwd usually imply a Unix-type system, but cmd is a
>> Windows thing.
>>
>> Then give examples of what your cwd is, what string you're typing at the
>> shell prompt, and what's happening.
>
>
> Well, I'm on a ubuntu platform,

Good.  Linux seldom gets in the way.

> running subversion, but I can't commit
> this debugging tool into the working copy where I'm using it, so I
> maintain it in my home directory.  The tool does use production
> packages, though.
>
> So, if I say,
>
>    $ python fapi-test.py
>
> and fapi-test.py really is there,

where?  Be explicit.  When copying the python invocation line above, you 
never bothered to include the current directory that's generally 
displayed right in front of that $ prompt.

> then it works, using the codec
> production package.

What codec production package.  And where is it installed?  And how do 
you intend that Python find it?

   But if I use a symlink instead,

So you delete the pfapi-tst.py out of the current directory, and create 
instead a symlink in the current directory that points to its real 
location  And without changing current directory, you run the same 
command and it runs till it gets to the import line, at which point it 
gives a traceback that has nothing to do with the file you're running??? 
  The traceback thinks you're running test2.py.

  it says
>
> Traceback (most recent call last):
>    File "test2", line 1, in <module>
>      from codec.support import *
> ImportError: No module named codec.support
>
>
> Python tells me Python 2.6.5 (r265:79063, Apr 16 2010, 13:09:56)
>
>

Take a look at Stephen's example.  He runs some things, shows you 
exactly what he's running, and what happens.  The things he runs may not 
match what you did, but we cannot tell.

 From within your script, you can display os.getcwd(), you can ...


import sys, os
print "cwd is", os.getcwd()
print "file is",  __file__
print "PATH is", os.getenv("PATH")
print "python-path is", os.getenv("PYTHONPATH")
print "sys.path is", sys.path

import codec
print "codec file is", codec.__file__

if you run that both as a regular file and on a symlink pointing to that 
file, comparing the two runs could give you a clue as to what's 
different.  My suspicion is that you have a different cwd when you test 
it the second way.

-- 
DaveA


From steve+comp.lang.python at pearwood.info  Thu May 16 05:04:02 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 16 May 2013 09:04:02 GMT
Subject: executing python scripts that are symlinked
References: <95bc1155-0a83-4ab1-8b76-68a819b2e29a@en2g2000vbb.googlegroups.com>
Message-ID: <5194a102$0$29978$c3e8da3$5496439d@news.astraweb.com>

On Thu, 16 May 2013 00:48:45 -0700, Charles Smith wrote:

> Hi.
> 
> How can I say, from the cmd line, that python should take my CWD as my
> CWD, and not the directory where the script actually is?

*scratches head*

Python does use your current working directory as your current working 
directory. I think you are misdiagnosing the problem.

Here's a demonstration:

steve at runes:~$ cat test.py
import os
print os.getcwd()


steve at runes:~$ ln -s ~/test.py /tmp/test
steve at runes:~$ ls -l /tmp/test 
lrwxrwxrwx 1 steve steve 19 May 16 18:58 /tmp/test -> /home/steve/test.py
steve at runes:~$ cd /etc/
steve at runes:/etc$ python /tmp/test 
/etc


> I have a python script that works fine when it sits in directory WC, but
> if I move it out of WC to H and put a symlink from H/script to WC, it
> doesn't find the packages that are in WC.  Also, if I use the absolute
> path to H, it won't find them, but I guess I can understand that.

The obvious solution is to make sure that WC is in the Python path. You 
can do that by adding it the environment variable PYTHONPATH, or by 
adding it to sys.path at the start of your script. I think you can also 
use a .pth file as well.

Another solution may be to add this to the beginning of your script:

os.setcwd('path/to/WC')

but that's a crappy solution, you generally don't want to be changing the 
working directory from inside scripts if you can avoid it.



-- 
Steven


From cts.private.yahoo at gmail.com  Thu May 16 05:23:35 2013
From: cts.private.yahoo at gmail.com (Charles Smith)
Date: Thu, 16 May 2013 02:23:35 -0700 (PDT)
Subject: executing python scripts that are symlinked
References: <95bc1155-0a83-4ab1-8b76-68a819b2e29a@en2g2000vbb.googlegroups.com>
	<5194a102$0$29978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <216f1770-b7f0-44bb-9953-7a6d573663d5@dl10g2000vbb.googlegroups.com>

On 16 Mai, 11:04, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
> Python does use your current working directory as your current working
> directory. I think you are misdiagnosing the problem.


That's usually how it ends up ...



>
> Here's a demonstration:
>
> steve at runes:~$ cat test.py
> import os
> print os.getcwd()
>
> steve at runes:~$ ln -s ~/test.py /tmp/test
> steve at runes:~$ ls -l /tmp/test
> lrwxrwxrwx 1 steve steve 19 May 16 18:58 /tmp/test -> /home/steve/test.py
> steve at runes:~$ cd /etc/
> steve at runes:/etc$ python /tmp/test
> /etc


You're right.  I can believe that python doesn't really change it's
notion of the CWD.

It seems like when I'm in WC and invoke ./script (which is symlinked
to H/script), python says, "I have a specification somewhere that says
I can look for modules where my script is, and since I'm really smart,
I happen to know that I'm in WC but the script is not, but is really
in H, where the stupid operator better have his packages set up"


>
> > I have a python script that works fine when it sits in directory WC, but
> > if I move it out of WC to H and put a symlink from H/script to WC, it
> > doesn't find the packages that are in WC. ?Also, if I use the absolute
> > path to H, it won't find them, but I guess I can understand that.
>
> The obvious solution is to make sure that WC is in the Python path.
...

> but that's a crappy solution,

Right.  Other tools don't try to figure out what I really want to do
with a symlink, but just accept that it's a file.  Python should do
the same ...

But, as you say, I'm surely misdiagnosing the problem.



From mal at egenix.com  Thu May 16 03:53:33 2013
From: mal at egenix.com (M.-A. Lemburg)
Date: Thu, 16 May 2013 09:53:33 +0200
Subject: EuroPython 2014/2015 Conference Team - Call for Proposals
Message-ID: <5194907D.10603@egenix.com>

The EuroPython Society (EPS) is happy to announce the Call for Proposals for
the EuroPython Conference in 2014 and 2015.  This Call for Proposals is meant
to collect proposals from teams that volunteer for organizing the EuroPython
conference in 2014-2015.

The Call for Proposals document containing all the details and information
about the proposals and selection process can be found here:

https://docs.google.com/file/d/0B8YBdLoQM_6fbVpuM2ZWUGp3Slk/edit?usp=sharing

If you are part of a great team organizing amazing Python events you could be
the team organizing the next EuroPython! Please also forward this Call for
Proposals to anyone that you feel may be interested.

The Call for Proposals will run until Friday, June 14th. Proposals must be
submitted to europython-contact at python.org before that day, and must adhere
the requirements specified in the CFP document.

Regards,
--
Marc-Andre Lemburg
Director
EuroPython Society
http://www.europython.eu/



From serge.weinstock at uk.bnpparibas.com  Thu May 16 04:55:07 2013
From: serge.weinstock at uk.bnpparibas.com (Serge WEINSTOCK)
Date: Thu, 16 May 2013 08:55:07 +0000
Subject: Python C-API: how to define nested classes?
Message-ID: <F4784E858CF3D843B7D0E5D3DE563EED2BA5E7DD@LONS00110044.mercury.intra>

Hi,

I'm currently writing a C extension module for python using the "raw" C-API. I would like to be able to define "nested classes" like in the following python code

============================================================
class A:
    class B:
        def __init__(self):
            self.i = 2
    def __init__(self):
        self.b = A.B()
a = A()
b = A.B()
print(a.b.i)
print(b.i)
============================================================

How can I create such nested class with the C-API?

Serge WEINSTOCK


___________________________________________________________
This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited.

Please refer to http://www.bnpparibas.co.uk/en/email-disclaimer/ for additional disclosures.
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From dihedral88888 at googlemail.com  Thu May 16 17:22:42 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Thu, 16 May 2013 14:22:42 -0700 (PDT)
Subject: Python C-API: how to define nested classes?
In-Reply-To: <mailman.1742.1368694819.3114.python-list@python.org>
References: <mailman.1742.1368694819.3114.python-list@python.org>
Message-ID: <b86e1be7-fc15-496e-8367-fb4d47b6dc07@googlegroups.com>

Serge WEINSTOCK? 2013?5?16????UTC+8??4?55?07????
> Hi,
> 
> ?
> 
> I'm currently writing a C extension module for python using the "raw" C-API. I would like to be able to define "nested classes" like in the following python code
> 
> ?
> 
> ============================================================
> 
> class A:
> 
> ??? class B:
> 
> ??????? def __init__(self):
> 
> ??????????? self.i = 2
> 
> ??? def __init__(self):
> 
> ??????? self.b = A.B()
> 
> a = A()
> 
> b = A.B()
> 
> print(a.b.i)
> 
> print(b.i)
> 
> ============================================================
> 
> ?
> 
> How can I create such nested class with the C-API?
> 
> ?
> 
> Serge WEINSTOCK
> 
> ?
> 
> 
> 
> 
> ___________________________________________________________
> 
> This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited.
> 
> 
> Please refer to http://www.bnpparibas.co.uk/en/email-disclaimer/ for additional disclosures.

The nested class is just defining the scope of the nested 
class object that can be  used solely in all outer proper 
classes.

It is not very useful in a language which supports 
dynamical run-time attribute binding in the instance level.

in the outer 


From stefan_ml at behnel.de  Fri May 17 01:16:25 2013
From: stefan_ml at behnel.de (Stefan Behnel)
Date: Fri, 17 May 2013 07:16:25 +0200
Subject: Python C-API: how to define nested classes?
In-Reply-To: <F4784E858CF3D843B7D0E5D3DE563EED2BA5E7DD@LONS00110044.mercury.intra>
References: <F4784E858CF3D843B7D0E5D3DE563EED2BA5E7DD@LONS00110044.mercury.intra>
Message-ID: <kn4ef4$m9p$1@ger.gmane.org>

Serge WEINSTOCK, 16.05.2013 10:55:
> I'm currently writing a C extension module for python using the "raw" C-API. I would like to be able to define "nested classes" like in the following python code
> 
> ============================================================
> class A:
>     class B:
>         def __init__(self):
>             self.i = 2
>     def __init__(self):
>         self.b = A.B()
> a = A()
> b = A.B()
> print(a.b.i)
> print(b.i)
> ============================================================
> 
> How can I create such nested class with the C-API?

Assuming you really mean Python classes and not extension types, you might
get away with defining them separately and then assigning

   A.B = B

Recent Python versions added a __qualname__ attribute for classes that you
might want to fix up in this case.

If you need better compatibility, consider writing your code in Cython.

Stefan




From fabiofz at gmail.com  Thu May 16 07:27:03 2013
From: fabiofz at gmail.com (Fabio Zadrozny)
Date: Thu, 16 May 2013 08:27:03 -0300
Subject: PyDev 2.7.4 Released
Message-ID: <CANXBEFqpu0sSv3bzC8xwCeLT7way+VVxFHC7Vz45QJVRi68m8g@mail.gmail.com>

Hi All,

PyDev 2.7.4 has been released

Details on PyDev: http://pydev.org
Details on its development: http://pydev.blogspot.com

Release Highlights:
-------------------------------

* Improved Jython scripting startup time (so, the editor should start up
faster).

* PyDev no longer causing JSP problem annotation disappear (fix by Danny
Ju).

* Restored invalidateTextPresentation on save due to issue on annotations
kept.

* Thank you everyone for helping to keep PyDev going:
http://pydev.blogspot.com.br/2013/05/pydev-crowdfunding-finished.html

What is PyDev?
---------------------------

PyDev is a plugin that enables users to use Eclipse for Python, Jython and
IronPython development -- making Eclipse a first class Python IDE -- It
comes with many goodies such as code completion, syntax highlighting,
syntax analysis, refactor, debug and many others.


Cheers,

-- 
Fabio Zadrozny
------------------------------------------------------
Software Developer

PyDev - Python Development Environment for Eclipse
http://pydev.org
http://pydev.blogspot.com
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From jldunn2000 at gmail.com  Thu May 16 11:00:25 2013
From: jldunn2000 at gmail.com (loial)
Date: Thu, 16 May 2013 08:00:25 -0700 (PDT)
Subject: spilt question
Message-ID: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>

I want to split a string so that I always return everything BEFORE the LAST underscore

HELLO_xxxxxxxx.lst         # should return HELLO
HELLO_GOODBYE_xxxxxxxx.ls  # should return HELLO_GOODBYE

I have tried with rsplit but cannot get it to work.

Any help appreciated



From fabiosantosart at gmail.com  Thu May 16 11:14:27 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 16 May 2013 16:14:27 +0100
Subject: spilt question
In-Reply-To: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
References: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
Message-ID: <CAA=1kxTD7dvg9Z4f2VSx_cbF-ds-vnPPnappGr__U7P8SfiO9g@mail.gmail.com>

str.split takes a limit argument. Try your_string.split('_', 1)
On 16 May 2013 16:11, "loial" <jldunn2000 at gmail.com> wrote:

> I want to split a string so that I always return everything BEFORE the
> LAST underscore
>
> HELLO_xxxxxxxx.lst         # should return HELLO
> HELLO_GOODBYE_xxxxxxxx.ls  # should return HELLO_GOODBYE
>
> I have tried with rsplit but cannot get it to work.
>
> Any help appreciated
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From walterhurry at lavabit.com  Thu May 16 11:10:14 2013
From: walterhurry at lavabit.com (Walter Hurry)
Date: Thu, 16 May 2013 15:10:14 +0000 (UTC)
Subject: spilt question
References: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
Message-ID: <kn2ssm$rqg$1@news.albasani.net>

On Thu, 16 May 2013 08:00:25 -0700, loial wrote:

> I want to split a string so that I always return everything BEFORE the
> LAST underscore
> 
> HELLO_xxxxxxxx.lst         # should return HELLO
> HELLO_GOODBYE_xxxxxxxx.ls  # should return HELLO_GOODBYE
> 
> I have tried with rsplit but cannot get it to work.
> 
mystr.rsplit("_",1)[0]


From rosuav at gmail.com  Thu May 16 11:15:39 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 17 May 2013 01:15:39 +1000
Subject: spilt question
In-Reply-To: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
References: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
Message-ID: <CAPTjJmoqD_gj25Pvo-cP30A_Ujc=7sVHp-xV=G8U6zbQbTk5Pw@mail.gmail.com>

On Fri, May 17, 2013 at 1:00 AM, loial <jldunn2000 at gmail.com> wrote:
> I want to split a string so that I always return everything BEFORE the LAST underscore
>
> HELLO_xxxxxxxx.lst         # should return HELLO
> HELLO_GOODBYE_xxxxxxxx.ls  # should return HELLO_GOODBYE
>
> I have tried with rsplit but cannot get it to work.
>
> Any help appreciated

Try with a limit:

>>> "HELLO_GOODBYE_xxxxxxxx.ls".rsplit("_",1)
['HELLO_GOODBYE', 'xxxxxxxx.ls']
>>> "HELLO_GOODBYE_xxxxxxxx.ls".rsplit("_",1)[0]
'HELLO_GOODBYE'

You can easily get docs on it:

>>> help("".rsplit)
Help on built-in function rsplit:

rsplit(...)
    S.rsplit(sep=None, maxsplit=-1) -> list of strings

    Return a list of the words in S, using sep as the
    delimiter string, starting at the end of the string and
    working to the front.  If maxsplit is given, at most maxsplit
    splits are done. If sep is not specified, any whitespace string
    is a separator.

ChrisA


From davea at davea.name  Thu May 16 11:32:36 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 16 May 2013 11:32:36 -0400
Subject: spilt question
In-Reply-To: <CAPTjJmoqD_gj25Pvo-cP30A_Ujc=7sVHp-xV=G8U6zbQbTk5Pw@mail.gmail.com>
References: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
	<CAPTjJmoqD_gj25Pvo-cP30A_Ujc=7sVHp-xV=G8U6zbQbTk5Pw@mail.gmail.com>
Message-ID: <5194FC14.6060808@davea.name>

On 05/16/2013 11:15 AM, Chris Angelico wrote:
> On Fri, May 17, 2013 at 1:00 AM, loial <jldunn2000 at gmail.com> wrote:
>> I want to split a string so that I always return everything BEFORE the LAST underscore
>>
>> HELLO_xxxxxxxx.lst         # should return HELLO
>> HELLO_GOODBYE_xxxxxxxx.ls  # should return HELLO_GOODBYE
>>
>> I have tried with rsplit but cannot get it to work.
>>
>> Any help appreciated
>
> Try with a limit:
>
>>>> "HELLO_GOODBYE_xxxxxxxx.ls".rsplit("_",1)
> ['HELLO_GOODBYE', 'xxxxxxxx.ls']
>>>> "HELLO_GOODBYE_xxxxxxxx.ls".rsplit("_",1)[0]
> 'HELLO_GOODBYE'
>
> You can easily get docs on it:
>
>>>> help("".rsplit)
> Help on built-in function rsplit:
>
> rsplit(...)
>      S.rsplit(sep=None, maxsplit=-1) -> list of strings
>
>      Return a list of the words in S, using sep as the
>      delimiter string, starting at the end of the string and
>      working to the front.  If maxsplit is given, at most maxsplit
>      splits are done. If sep is not specified, any whitespace string
>      is a separator.
>
> ChrisA
>

Now that you've all done his homework for him, see if The OP can spot 
the one case where that won't work.  It's easy to test for, but still 
important to get right (for some definition of right).

-- 
DaveA


From davea at davea.name  Thu May 16 11:20:25 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 16 May 2013 11:20:25 -0400
Subject: spilt question
In-Reply-To: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
References: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
Message-ID: <5194F939.8010109@davea.name>

On 05/16/2013 11:00 AM, loial wrote:
> I want to split a string so that I always return everything BEFORE the LAST underscore
>
> HELLO_xxxxxxxx.lst         # should return HELLO
> HELLO_GOODBYE_xxxxxxxx.ls  # should return HELLO_GOODBYE
>
> I have tried with rsplit but cannot get it to work.
>
> Any help appreciated
>

The rsplit() method was a good idea; it will work.  So exactly what did 
you try and what about it did not work.  How are you stuck going from 
your partial answer to a complete one?

While you're at it, you need to consider at least two more cases

HELLO.txt                    #should return ""
HELLO_and_____goodbye        #should return "HELLO_and____"

-- 
DaveA


From python.list at tim.thechases.com  Thu May 16 11:23:42 2013
From: python.list at tim.thechases.com (Tim Chase)
Date: Thu, 16 May 2013 10:23:42 -0500
Subject: spilt question
In-Reply-To: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
References: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
Message-ID: <20130516102342.694b6f48@bigbox.christie.dr>

On 2013-05-16 08:00, loial wrote:
> I want to split a string so that I always return everything BEFORE
> the LAST underscore
> 
> HELLO_xxxxxxxx.lst         # should return HELLO
> HELLO_GOODBYE_xxxxxxxx.ls  # should return HELLO_GOODBYE
> 
> I have tried with rsplit but cannot get it to work.

 .rsplit takes an optional "how many splits do you want?" parameter
 that defaults to giving you all of them.  Just ask for one
 right-most split:

  TESTS = [
     ("HELLO_xxxxxxx.lst", "HELLO"),
     ("HELLO_GOODBYE_xxxxx.ls", "HELLO_GOODBYE"),
     ]

  for input, expected in TESTS:
    result = input.rsplit('_', 1)[0]
    if result == expected:
      verdict = "passed"
    else:
      verdict = "failed"
    print "%r -> %r == %r  (%s)" % (
      input,
      result,
      expected,
      verdict,
      )

-tkc





From ned at nedbatchelder.com  Thu May 16 11:22:15 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Thu, 16 May 2013 11:22:15 -0400
Subject: spilt question
In-Reply-To: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
References: <d8c03de0-dc35-45e3-a6b2-2af39feb9e79@googlegroups.com>
Message-ID: <5194F9A7.7070200@nedbatchelder.com>

On 5/16/2013 11:00 AM, loial wrote:
> I want to split a string so that I always return everything BEFORE the LAST underscore
>
> HELLO_xxxxxxxx.lst         # should return HELLO
> HELLO_GOODBYE_xxxxxxxx.ls  # should return HELLO_GOODBYE
>
> I have tried with rsplit but cannot get it to work.
>
> Any help appreciated
>
     >>> "HELLO_GOODBYE_xxxxxxxx.ls".rpartition('_')
    ('HELLO_GOODBYE', '_', 'xxxxxxxx.ls')
     >>> "HELLO_GOODBYE_xxxxxxxx.ls".rsplit('_', 1)
    ['HELLO_GOODBYE', 'xxxxxxxx.ls']
     >>> "HELLO_GOODBYE_xxxxxxxx.ls".rpartition('_')[0]
    'HELLO_GOODBYE'
     >>> "HELLO_GOODBYE_xxxxxxxx.ls".rsplit('_', 1)[0]
    'HELLO_GOODBYE'


For the future, getting help works better if you show what you tried, 
and what it produced.

--Ned.
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From visphatesjava at gmail.com  Thu May 16 14:14:44 2013
From: visphatesjava at gmail.com (visphatesjava at gmail.com)
Date: Thu, 16 May 2013 11:14:44 -0700 (PDT)
Subject: so if zodb has no index or search, how run fast query?
Message-ID: <a827dd9f-1389-4d7d-9c1e-a15639225648@googlegroups.com>

how?

and what package provides such?


From wuwei23 at gmail.com  Thu May 16 20:08:49 2013
From: wuwei23 at gmail.com (alex23)
Date: Thu, 16 May 2013 17:08:49 -0700 (PDT)
Subject: so if zodb has no index or search, how run fast query?
References: <a827dd9f-1389-4d7d-9c1e-a15639225648@googlegroups.com>
Message-ID: <a9559b61-7a53-4a4d-81b0-fbecbd32d286@h9g2000pbr.googlegroups.com>

On May 17, 4:14?am, visphatesj... at gmail.com wrote:
> how?
>
> and what package provides such?

https://pypi.python.org/pypi/zope.index
https://pypi.python.org/pypi/zope.app.catalog

I can see how those would be pretty difficult to find...


From dieter at handshake.de  Fri May 17 02:47:46 2013
From: dieter at handshake.de (dieter)
Date: Fri, 17 May 2013 08:47:46 +0200
Subject: so if zodb has no index or search, how run fast query?
References: <a827dd9f-1389-4d7d-9c1e-a15639225648@googlegroups.com>
Message-ID: <87k3mym7al.fsf@handshake.de>

visphatesjava at gmail.com writes:
> ...
The only service of the ZODB is storing (persistent) objects
persistently and providing (almost) transparent acces to them.
Persistent objects have a (usually) implicitely
managed attribute which contains the object's "object id"
and the ZODB can (quite) efficiently access the objects based
on its "object id" (it is using caches and indexes for this).

The objects managed by the ZODB form a (directed) graph with
a distinguished root node - where all nodes are (persistent)
Python objects. You essentially work with those persistent objects
as with normal Python objects: the ZODB transparently accesses
the persistent storage, when necessary, to give you
the feeling as if those objects were normal Python objects.
There are a few caveats with respect to modifications -
but most modifications work as you would expect for
"normal" Python objects (however, you must call "transaction.commit()",
in order to persist the modifications).

That is essentially all, the ZODB does for you.
When you need searches, you must use appropriate datatypes --
in the same way, you would need to do this in a "normal" Python program.

The ZODB comes with a collection of datatypes (so called "BTrees")
which may form the base for searches.
"BTrees" are essentially persistent dicts - however, they
are not build from a fixed number of persistent subobjects but
the persistent substructure is changed automatically to accommodate
efficiently for various tree sizes.

Someone else has already mentioned some higher level packages which 
can provide search capabilities.



From visphatesjava at gmail.com  Thu May 16 14:15:45 2013
From: visphatesjava at gmail.com (visphatesjava at gmail.com)
Date: Thu, 16 May 2013 11:15:45 -0700 (PDT)
Subject: wil anyone ressurect medusa and pypersist?
Message-ID: <50e6d4bc-ce2f-4c55-97b0-ec0cad793682@googlegroups.com>

www.prevayler.org in python = pypersist

medusa = python epoll web server and ftp server eventy and async


From visphatesjava at gmail.com  Thu May 16 14:17:37 2013
From: visphatesjava at gmail.com (visphatesjava at gmail.com)
Date: Thu, 16 May 2013 11:17:37 -0700 (PDT)
Subject: any cherypy powred sites I can check out?
Message-ID: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>

anyone?


From rosuav at gmail.com  Thu May 16 14:30:54 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 17 May 2013 04:30:54 +1000
Subject: any cherypy powred sites I can check out?
In-Reply-To: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
Message-ID: <CAPTjJmqFzhEb=Gd_sHmz4cKgoNpJ4p=rEA8Ex-EubK-_XrmjYg@mail.gmail.com>

On Fri, May 17, 2013 at 4:17 AM,  <visphatesjava at gmail.com> wrote:
> anyone?
> --
> http://mail.python.org/mailman/listinfo/python-list

You're firing off a bunch of minimal-content threads that ask other
people to do work for you. I recommend you put a bit more thought into
your posts, and show that you're willing to do a basic web search
before you just ask a question :)

Have a read of this:

http://www.catb.org/esr/faqs/smart-questions.html

ChrisA


From walterhurry at lavabit.com  Thu May 16 15:11:13 2013
From: walterhurry at lavabit.com (Walter Hurry)
Date: Thu, 16 May 2013 19:11:13 +0000 (UTC)
Subject: any cherypy powred sites I can check out?
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
Message-ID: <kn3b0h$qgh$1@news.albasani.net>

On Thu, 16 May 2013 11:17:37 -0700, visphatesjava wrote:

> anyone?

Questions asked in that fashion stand little chance of eliciting helpful 
responses.



From skip at pobox.com  Thu May 16 15:24:02 2013
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 16 May 2013 14:24:02 -0500
Subject: any cherypy powred sites I can check out?
In-Reply-To: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
Message-ID: <CANc-5UzQ-97sGW91P7M0zDFFhTv13q_cewU4vTEejr_wZNDNYA@mail.gmail.com>

On Thu, May 16, 2013 at 1:17 PM,  <visphatesjava at gmail.com> wrote:
> anyone?

Perhaps asking this question (or a more precise one) on a CherryPy
mailing list would elicit more (helpful) responses.  If you just
repeat the above though, I'm afraid most of the answers will just be,
"yes."

Hint:  Read through this before asking the CherryPy folks for help:

http://www.catb.org/esr/faqs/smart-questions.html

Skip


From visphatesjava at gmail.com  Thu May 16 20:00:02 2013
From: visphatesjava at gmail.com (visphatesjava at gmail.com)
Date: Thu, 16 May 2013 17:00:02 -0700 (PDT)
Subject: any cherypy powred sites I can check out?
In-Reply-To: <mailman.1768.1368729058.3114.python-list@python.org>
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1768.1368729058.3114.python-list@python.org>
Message-ID: <17260e56-d23f-4396-92dc-26c37546c35a@googlegroups.com>

fuck straight off



From breamoreboy at yahoo.co.uk  Fri May 17 13:15:38 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 17 May 2013 18:15:38 +0100
Subject: any cherypy powred sites I can check out?
In-Reply-To: <17260e56-d23f-4396-92dc-26c37546c35a@googlegroups.com>
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1768.1368729058.3114.python-list@python.org>
	<17260e56-d23f-4396-92dc-26c37546c35a@googlegroups.com>
Message-ID: <kn5ojk$ci9$1@ger.gmane.org>

On 17/05/2013 01:00, visphatesjava at gmail.com wrote:
> fuck straight off
>

I assume you're the author of "How to win friends and influence people"?

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From rosuav at gmail.com  Fri May 17 13:23:48 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 18 May 2013 03:23:48 +1000
Subject: any cherypy powred sites I can check out?
In-Reply-To: <kn5ojk$ci9$1@ger.gmane.org>
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1768.1368729058.3114.python-list@python.org>
	<17260e56-d23f-4396-92dc-26c37546c35a@googlegroups.com>
	<kn5ojk$ci9$1@ger.gmane.org>
Message-ID: <CAPTjJmq_udUutHF1KYskixSKLuw4kEUfq_yasb7aVj-zm9q0bg@mail.gmail.com>

On Sat, May 18, 2013 at 3:15 AM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 17/05/2013 01:00, visphatesjava at gmail.com wrote:
>>
>> fuck straight off
>>
>
> I assume you're the author of "How to win friends and influence people"?

Not quite. He's the author of the social networking version, "How to
win influence and friend people".

ChrisA


From walterhurry at lavabit.com  Fri May 17 14:51:01 2013
From: walterhurry at lavabit.com (Walter Hurry)
Date: Fri, 17 May 2013 18:51:01 +0000 (UTC)
Subject: any cherypy powred sites I can check out?
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1768.1368729058.3114.python-list@python.org>
	<17260e56-d23f-4396-92dc-26c37546c35a@googlegroups.com>
	<mailman.1786.1368810952.3114.python-list@python.org>
Message-ID: <kn5u6l$oi4$1@news.albasani.net>

On Fri, 17 May 2013 18:15:38 +0100, Mark Lawrence wrote:

> On 17/05/2013 01:00, visphatesjava at gmail.com wrote:
>> fuck straight off
>>
>>
> I assume you're the author of "How to win friends and influence people"?

There are very few posters to this NG in the Hurry bozo bin, but OP is 
now one.


From neilc at norwich.edu  Fri May 17 15:27:59 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 17 May 2013 19:27:59 GMT
Subject: any cherypy powred sites I can check out?
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1768.1368729058.3114.python-list@python.org>
	<17260e56-d23f-4396-92dc-26c37546c35a@googlegroups.com>
	<mailman.1786.1368810952.3114.python-list@python.org>
Message-ID: <avnelvFmkr2U1@mid.individual.net>

On 2013-05-17, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 17/05/2013 01:00, visphatesjava at gmail.com wrote:
>> fuck straight off
>
> I assume you're the author of "How to win friends and influence
> people"?

'"I recently wrote a book called "How to Get Along with
Everybody." I didn't write it myself--I wrote it some asshole.'
  --Steve Martin

-- 
Neil Cerutti


From kw at codebykevin.com  Sun May 19 20:27:02 2013
From: kw at codebykevin.com (Kevin Walzer)
Date: Sun, 19 May 2013 20:27:02 -0400
Subject: any cherypy powred sites I can check out?
In-Reply-To: <mailman.1768.1368729058.3114.python-list@python.org>
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1768.1368729058.3114.python-list@python.org>
Message-ID: <knbqd7$ub9$1@dont-email.me>

On 5/16/13 2:30 PM, Chris Angelico wrote:
> On Fri, May 17, 2013 at 4:17 AM,  <visphatesjava at gmail.com> wrote:
>> anyone?
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
> You're firing off a bunch of minimal-content threads that ask other
> people to do work for you. I recommend you put a bit more thought into
> your posts, and show that you're willing to do a basic web search
> before you just ask a question :)
>

He's also known on the Tcl newsgroup as Gavino; a Google search for 
"gavino tcl" will turn up some interesting hits. I also see that he's 
posting on comp.lang.perl as "Johannes Falcone." The common thread of 
his recent postings are subjects posed as questions, usually about 
various web frameworks, sometimes without even a single line in the 
message body. On the Tcl list it's AOLServer and NavServer. I'm not 
familiar with the Perl frameworks he's curious about.

--Kevin


-- 
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
http://www.wtmobilesoftware.com


From visphatesjava at gmail.com  Thu May 16 20:00:31 2013
From: visphatesjava at gmail.com (visphatesjava at gmail.com)
Date: Thu, 16 May 2013 17:00:31 -0700 (PDT)
Subject: any cherypy powred sites I can check out?
In-Reply-To: <mailman.1773.1368732245.3114.python-list@python.org>
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1773.1368732245.3114.python-list@python.org>
Message-ID: <314b2dd0-2f96-4ce7-bae0-92e8b7d939b3@googlegroups.com>

is a cherrypy list accessible here on web thru google groups?



From wuwei23 at gmail.com  Thu May 16 20:09:38 2013
From: wuwei23 at gmail.com (alex23)
Date: Thu, 16 May 2013 17:09:38 -0700 (PDT)
Subject: any cherypy powred sites I can check out?
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1773.1368732245.3114.python-list@python.org>
	<314b2dd0-2f96-4ce7-bae0-92e8b7d939b3@googlegroups.com>
Message-ID: <86905dc4-31cf-4bec-94dc-847797e54269@ul7g2000pbc.googlegroups.com>

On May 17, 10:00?am, visphatesj... at gmail.com wrote:
> is a cherrypy list accessible here on web thru google groups?

Is an apology for your offensive response to Chris Angelico
forthcoming?


From rosuav at gmail.com  Thu May 16 21:48:19 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 17 May 2013 11:48:19 +1000
Subject: any cherypy powred sites I can check out?
In-Reply-To: <86905dc4-31cf-4bec-94dc-847797e54269@ul7g2000pbc.googlegroups.com>
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1773.1368732245.3114.python-list@python.org>
	<314b2dd0-2f96-4ce7-bae0-92e8b7d939b3@googlegroups.com>
	<86905dc4-31cf-4bec-94dc-847797e54269@ul7g2000pbc.googlegroups.com>
Message-ID: <CAPTjJmpb=fguoBZuS=nsxxf9dGvMPS=aN6hu_7vzVUJP7hUCFw@mail.gmail.com>

On Fri, May 17, 2013 at 10:09 AM, alex23 <wuwei23 at gmail.com> wrote:
> On May 17, 10:00 am, visphatesj... at gmail.com wrote:
>> is a cherrypy list accessible here on web thru google groups?
>
> Is an apology for your offensive response to Chris Angelico
> forthcoming?

In complete absence of all semblance of context, I do not see the
profane post as addressing me personally. But in lieu of an apology,
I'd settle for a little more content in the posts.... or some evidence
that he's read ESR Question. You know what, I'd settle for the latter
in lieu of pretty much anything.

I still think we should use that as a penance. Go and say three Our
Fathers, do a Stations of the Cross, and read esr's article on smart
questions. You are forgiven, my son.

ChrisA

(Caveat: I am not a Catholic, so I haven't much of a clue as to how
confession usually goes.)


From walterhurry at lavabit.com  Sun May 19 15:46:20 2013
From: walterhurry at lavabit.com (Walter Hurry)
Date: Sun, 19 May 2013 19:46:20 +0000 (UTC)
Subject: any cherypy powred sites I can check out?
References: <e4159a8f-8878-46b4-b158-3736c594c5f2@googlegroups.com>
	<mailman.1773.1368732245.3114.python-list@python.org>
	<314b2dd0-2f96-4ce7-bae0-92e8b7d939b3@googlegroups.com>
	<86905dc4-31cf-4bec-94dc-847797e54269@ul7g2000pbc.googlegroups.com>
	<mailman.1836.1368944986.3114.python-list@python.org>
Message-ID: <knba6c$n6g$2@news.albasani.net>

On Fri, 17 May 2013 11:48:19 +1000, Chris Angelico wrote:

> (Caveat: I am not a Catholic, so I haven't much of a clue as to how
> confession usually goes.)

Forgive OP Father, for he has sinned...



From tunacubes at gmail.com  Thu May 16 14:29:25 2013
From: tunacubes at gmail.com (tunacubes at gmail.com)
Date: Thu, 16 May 2013 11:29:25 -0700 (PDT)
Subject: Number of cells, using CSV module
Message-ID: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>

I'm using the csv module to get information from a csv file. I have items listed in Column A. I want to know how many items are listed in Column A. 

import csv
with open('test.csv', 'r') as f:
    reader = csv.reader(f)
    for column in reader:
        column = (column[0])
        print(column)     

We are given

>a
>b
>c
>d
>e
>f

How would I go about getting the amount of numbers that are printed? If I try printing len(column), I get 
>1
>1
>1
>1
>1
>1


From skip at pobox.com  Thu May 16 14:40:08 2013
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 16 May 2013 13:40:08 -0500
Subject: Number of cells, using CSV module
In-Reply-To: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
References: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
Message-ID: <CANc-5Uxr+k6UgDp_EOo=7UpXZdoFAFf0qPpnLdHopPKpsUOCJw@mail.gmail.com>

Perhaps you want len(reader) instead?  Or a counter which increments for
every row read which has an item in column A?

Skip
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From tunacubes at gmail.com  Thu May 16 14:50:42 2013
From: tunacubes at gmail.com (tunacubes at gmail.com)
Date: Thu, 16 May 2013 11:50:42 -0700 (PDT)
Subject: Number of cells, using CSV module
In-Reply-To: <mailman.1769.1368729617.3114.python-list@python.org>
References: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
	<mailman.1769.1368729617.3114.python-list@python.org>
Message-ID: <8662be9c-e50c-48e9-86dc-1838c6188d0c@googlegroups.com>

On Thursday, May 16, 2013 2:40:08 PM UTC-4, Skip Montanaro wrote:
> Perhaps you want len(reader) instead? ?Or a counter which increments for every row read which has an item in column A?
> 
> 
> 
> Skip

len(reader) gives me an error. 

I tried a counter, but unfortunately due to the simplicity of CSV files, any formulas are not saved.


From skip at pobox.com  Thu May 16 15:07:49 2013
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 16 May 2013 14:07:49 -0500
Subject: Number of cells, using CSV module
In-Reply-To: <8662be9c-e50c-48e9-86dc-1838c6188d0c@googlegroups.com>
References: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
	<mailman.1769.1368729617.3114.python-list@python.org>
	<8662be9c-e50c-48e9-86dc-1838c6188d0c@googlegroups.com>
Message-ID: <CANc-5UxXaijcEDDM7moKn=KphRco5S+fA+innG1PQ4EM=W0PPQ@mail.gmail.com>

> len(reader) gives me an error.

Apologies.  len(list(reader)) should work.  Of course, you'll wind up
loading the entire CSV file into memory.  You might want to just count
row-by-row:

n = 0
for row in reader:
    n += 1

Skip


From python.list at tim.thechases.com  Thu May 16 16:00:21 2013
From: python.list at tim.thechases.com (Tim Chase)
Date: Thu, 16 May 2013 15:00:21 -0500
Subject: Number of cells, using CSV module
In-Reply-To: <CANc-5UxXaijcEDDM7moKn=KphRco5S+fA+innG1PQ4EM=W0PPQ@mail.gmail.com>
References: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
	<mailman.1769.1368729617.3114.python-list@python.org>
	<8662be9c-e50c-48e9-86dc-1838c6188d0c@googlegroups.com>
	<CANc-5UxXaijcEDDM7moKn=KphRco5S+fA+innG1PQ4EM=W0PPQ@mail.gmail.com>
Message-ID: <20130516150021.7d467219@bigbox.christie.dr>

On 2013-05-16 14:07, Skip Montanaro wrote:
> > len(reader) gives me an error.
> 
> Apologies.  len(list(reader)) should work.  Of course, you'll wind
> up loading the entire CSV file into memory.  You might want to just
> count row-by-row:
> 
> n = 0
> for row in reader:
>     n += 1

which can nicely be rewritten as

  n = sum(1 for row in reader)

:-)

-tkc




From tunacubes at gmail.com  Thu May 16 14:53:23 2013
From: tunacubes at gmail.com (tunacubes at gmail.com)
Date: Thu, 16 May 2013 11:53:23 -0700 (PDT)
Subject: Number of cells, using CSV module
In-Reply-To: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
References: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
Message-ID: <2cd2fe5b-a242-442e-a3fa-e0c5588a370a@googlegroups.com>

I guess another way to accomplish this would be, is there any way that I can turn the returned value for (column) into 1 list?

So rather than 
>a
>b
>c
>d
>e
>f 
I would get [a, b, c, d, e, f]


From skip at pobox.com  Thu May 16 15:08:29 2013
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 16 May 2013 14:08:29 -0500
Subject: Number of cells, using CSV module
In-Reply-To: <2cd2fe5b-a242-442e-a3fa-e0c5588a370a@googlegroups.com>
References: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
	<2cd2fe5b-a242-442e-a3fa-e0c5588a370a@googlegroups.com>
Message-ID: <CANc-5Ux8-tHE-EYcjQNixv8re=CVO+QUJWjU+QYH1gA0ZAiGrA@mail.gmail.com>

> So rather than
>>a
>>b
>>c
>>d
>>e
>>f
> I would get [a, b, c, d, e, f]

all_items = []
for row in reader:
    all_items.append(row[0])

Skip


From python.list at tim.thechases.com  Thu May 16 16:01:08 2013
From: python.list at tim.thechases.com (Tim Chase)
Date: Thu, 16 May 2013 15:01:08 -0500
Subject: Number of cells, using CSV module
In-Reply-To: <CANc-5Ux8-tHE-EYcjQNixv8re=CVO+QUJWjU+QYH1gA0ZAiGrA@mail.gmail.com>
References: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
	<2cd2fe5b-a242-442e-a3fa-e0c5588a370a@googlegroups.com>
	<CANc-5Ux8-tHE-EYcjQNixv8re=CVO+QUJWjU+QYH1gA0ZAiGrA@mail.gmail.com>
Message-ID: <20130516150108.2792c850@bigbox.christie.dr>

On 2013-05-16 14:08, Skip Montanaro wrote:
> > So rather than
> >>a
> >>b
> >>c
> >>d
> >>e
> >>f
> > I would get [a, b, c, d, e, f]
> 
> all_items = []
> for row in reader:
>     all_items.append(row[0])

And following up here, this could be tidily rewritten as

  all_items = [row[0] for row in reader]

-tkc





From tunacubes at gmail.com  Thu May 16 16:11:50 2013
From: tunacubes at gmail.com (tunacubes at gmail.com)
Date: Thu, 16 May 2013 13:11:50 -0700 (PDT)
Subject: Number of cells, using CSV module
In-Reply-To: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
References: <5f4aec0e-5cfa-445f-af50-67cca7caae36@googlegroups.com>
Message-ID: <28454e0b-b14d-4a71-9ac4-38e7397f44d7@googlegroups.com>

Thank you Skip, worked great. And thank you Tim for Tidying things up!


From chitrankdixit at gmail.com  Thu May 16 16:05:49 2013
From: chitrankdixit at gmail.com (Chitrank Dixit)
Date: Fri, 17 May 2013 01:35:49 +0530
Subject: How to use relative Import
Message-ID: <CAH7uNX37PSX34oPZLkz=h=pC9PMQtFWrZbhtY1rtVjOhx7ErXQ@mail.gmail.com>

Hello Python developers

I want to know how relative imports are different than import. I have found
lots of examples on internet explaining about the relative import

but I want to know about the basic aspects of relative import that make it
different than import.


*Regards
*
*Chitrank Dixit
*
*IIPS-DAVV
*
*Indore (M.P.) , India *
*MCA
*
*trackleech.blogspot.in*
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From steve+comp.lang.python at pearwood.info  Thu May 16 19:39:34 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 16 May 2013 23:39:34 GMT
Subject: How to use relative Import
References: <mailman.1777.1368734751.3114.python-list@python.org>
Message-ID: <51956e35$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 17 May 2013 01:35:49 +0530, Chitrank Dixit wrote:

> I want to know how relative imports are different than import. I have
> found lots of examples on internet explaining about the relative import
> but I want to know about the basic aspects of relative import that make 
> it different than import.

Relative imports search the directory containing the current package, 
absolute imports search the entire contents of sys.path. That is the only 
difference.

The purpose of relative imports is to make it easy for modules inside a 
package to import each other without worrying about other modules 
*outside* the package being imported by mistake. You can read the PEP 
here:

http://www.python.org/dev/peps/pep-0328/

to learn about the motivation for absolute and relative imports.

Optional in Python 2.5 and 2.6, and compulsory in 2.7, when you write:

import moduleX

Python looks at sys.path for a list of directories to search for 
"moduleX.py". This is an absolute import.

But consider a package with this structure:

package/
  +--  __init__.py
  +--  moduleA.py
  +--  moduleB.py
  +--  moduleX.py
  +--  subpackage/
       +--  __init__.py
       +--  moduleY.py
       +--  moduleZ.py


Inside moduleA, if you write "import moduleX" it will be an absolute 
import, the entire sys.path will be searched, and the "top level" 
module.X will be found.

But if you write this instead:

from . import moduleX

you have a relative import, and Python will only search the current 
package directory, so it will find the moduleX inside the package.

You can also write:

from .subpackage import moduleZ

to find the moduleZ inside the subpackage, again without searching the 
entire sys.path.

Inside moduleY in the subpackage, all of these will find the same moduleZ:

# Relative to the current module:
from . import moduleZ

# Relative to the parent of the current module:
from ..subpackage import moduleZ
from .. import subpackage.moduleZ

# Absolute:
import package.subpackage.moduleZ



-- 
Steven


From lokeshkoppaka at gmail.com  Thu May 16 23:20:26 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Thu, 16 May 2013 20:20:26 -0700 (PDT)
Subject: How to write fast into a file in python?
Message-ID: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>



I need to write numbers into a file upto 50mb and it should be fast
can any one help me how to do that?
i had written the following code..
-----------------------------------------------------------------------------------------------------------
def create_file_numbers_old(filename, size):
start = time.clock()

value = 0
with open(filename, "w") as f:
while f.tell()< size:
f.write("{0}\n".format(value))
value += 1

end = time.clock()

print "time taken to write a file of size", size, " is ", (end -start), "seconds \n"
------------------------------------------------------------------------------------------------------------------
it takes about 20sec i need 5 to 10 times less than that.


From steve+comp.lang.python at pearwood.info  Thu May 16 23:51:21 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 17 May 2013 03:51:21 GMT
Subject: How to write fast into a file in python?
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
Message-ID: <5195a939$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Thu, 16 May 2013 20:20:26 -0700, lokeshkoppaka wrote:

> I need to write numbers into a file upto 50mb and it should be fast can
> any one help me how to do that?
> i had written the following code..
> ----------------------------------------------------------------------
> def create_file_numbers_old(filename, size): start = time.clock()
> 
> value = 0
> with open(filename, "w") as f:
> while f.tell()< size:
> f.write("{0}\n".format(value))
> value += 1
> 
> end = time.clock()
> 
> print "time taken to write a file of size", size, " is ", (end -start),
> "seconds \n"
> --------------------------------------------------------------------
> it takes about 20sec i need 5 to 10 times less than that.


20 seconds to write how many numbers? If you are doing

create_file_numbers_old(filename, 5)

then 20 seconds is really slow. But if you are doing:

create_file_numbers_old(filename, 50000000000000)

then 20 seconds is amazingly fast.


Try this instead, it may be a little faster:


def create_file_numbers_old(filename, size):
    count = value = 0
    with open(filename, 'w') as f:
        while count < size:
            s = '%d\n' % value
            f.write(s)
            count += len(s)
            value += 1
            

If this is still too slow, you can try three other tactics:

1) pre-calculate the largest integer that will fit in `size` bytes, then 
use a for-loop instead of a while loop:

    maxn = calculation(...)
    with open(filename, 'w') as f:
        for i in xrange(maxn):
            f.write('%d\n' % i)


2) Write an extension module in C that writes to the file.

3) Get a faster hard drive, and avoid writing over a network.


-- 
Steven


From lokeshkoppaka at gmail.com  Fri May 17 00:35:15 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Thu, 16 May 2013 21:35:15 -0700 (PDT)
Subject: How to write fast into a file in python?
In-Reply-To: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
Message-ID: <87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>

On Friday, May 17, 2013 8:50:26 AM UTC+5:30, lokesh... at gmail.com wrote:
> I need to write numbers into a file upto 50mb and it should be fast
> 
> can any one help me how to do that?
> 
> i had written the following code..
> 
> -----------------------------------------------------------------------------------------------------------
> 
> def create_file_numbers_old(filename, size):
> 
> start = time.clock()
> 
> 
> 
> value = 0
> 
> with open(filename, "w") as f:
> 
> while f.tell()< size:
> 
> f.write("{0}\n".format(value))
> 
> value += 1
> 
> 
> 
> end = time.clock()
> 
> 
> 
> print "time taken to write a file of size", size, " is ", (end -start), "seconds \n"
> 
> ------------------------------------------------------------------------------------------------------------------
> 
> it takes about 20sec i need 5 to 10 times less than that.
size = 50mb


From davea at davea.name  Fri May 17 07:58:43 2013
From: davea at davea.name (Dave Angel)
Date: Fri, 17 May 2013 07:58:43 -0400
Subject: How to write fast into a file in python?
In-Reply-To: <87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
Message-ID: <51961B73.2070401@davea.name>

On 05/17/2013 12:35 AM, lokeshkoppaka at gmail.com wrote:
> On Friday, May 17, 2013 8:50:26 AM UTC+5:30, lokesh... at gmail.com wrote:
>> I need to write numbers into a file upto 50mb and it should be fast
>>
>> can any one help me how to do that?
>>
>> i had written the following code..
>>
>>  <SNIP>
>> value = 0
>>
>> with open(filename, "w") as f:
>>
>> while f.tell()< size:
>>
>> f.write("{0}\n".format(value))
>>   <SNIP more double-spaced nonsense from googlegroups>
   If you must use googlegroups, at least read this
   http://wiki.python.org/moin/GoogleGroupsPython.
>>
>>
>> it takes about 20sec i need 5 to 10 times less than that.
> size = 50mb
>

Most of the time is spent figuring out whether the file has reached its 
limit size.  If you want Python to go fast, just specify the data.  On 
my Linux system, it takes 11 seconds to write the first 6338888 values, 
which is just under 50mb.  If I write the obvious loop, writing that 
many values takes .25 seconds.

-- 
DaveA


From carlosnepomuceno at outlook.com  Fri May 17 11:20:33 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 17 May 2013 18:20:33 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <51961B73.2070401@davea.name>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	<51961B73.2070401@davea.name>
Message-ID: <BLU176-W28E2011D3BC9AC9DA5A9CED7AC0@phx.gbl>

I've got the following results on my desktop PC (Win7/Python2.7.5):

C:\src\Python>python -m timeit -cvn3 -r3 "execfile('fastwrite2.py')"
raw times: 123 126 125
3 loops, best of 3: 41 sec per loop

C:\src\Python>python -m timeit -cvn3 -r3 "execfile('fastwrite5.py')"
raw times: 34 34.3 34
3 loops, best of 3: 11.3 sec per loop

C:\src\Python>python -m timeit -cvn3 -r3 "execfile('fastwrite6.py')"
raw times: 0.4 0.447 0.391
3 loops, best of 3: 130 msec per loop


If you can just copy a preexisting file it will surely increase the speed to the levels you need, but doing the cStringIO operations can reduce the time in 72%.

Strangely I just realised that the time it takes to complete such scripts is the same no matter what hard drive I choose to run them. The results are the same for an SSD (main drive) and a HDD.

I think it's very strange to take 11.3s to write 50MB (4.4MB/s) sequentially on a SSD which is capable of 140MB/s.

Is that a Python problem? Why does it take the same time on the HDD?


### fastwrite2.py ###? <<< this is your code
size = 50*1024*1024
value = 0
filename = 'fastwrite2.dat'
with open(filename, "w") as f:
??? while f.tell()< size:
??????? f.write("{0}\n".format(value))
??????? value += 1
??? f.close()


### fastwrite5.py ###
import cStringIO
size = 50*1024*1024
value = 0
filename = 'fastwrite5.dat'
x = 0
b = cStringIO.StringIO()
while x < size:
??? line = '{0}\n'.format(value)
??? b.write(line)
??? value += 1
??? x += len(line)+1
f = open(filename, 'w')
f.write(b.getvalue())
f.close()
b.close()


### fastwrite6.py ###
import shutil
src = 'fastwrite.dat'
dst = 'fastwrite6.dat'
shutil.copyfile(src, dst)



----------------------------------------
> Date: Fri, 17 May 2013 07:58:43 -0400
> From: davea at davea.name
> To: python-list at python.org
> Subject: Re: How to write fast into a file in python?
>
> On 05/17/2013 12:35 AM, lokeshkoppaka at gmail.com wrote:
>> On Friday, May 17, 2013 8:50:26 AM UTC+5:30, lokesh... at gmail.com wrote:
>>> I need to write numbers into a file upto 50mb and it should be fast
>>>
>>> can any one help me how to do that?
>>>
>>> i had written the following code..
>>>
>>> <SNIP>
>>> value = 0
>>>
>>> with open(filename, "w") as f:
>>>
>>> while f.tell()< size:
>>>
>>> f.write("{0}\n".format(value))
>>> <SNIP more double-spaced nonsense from googlegroups>
> If you must use googlegroups, at least read this
> http://wiki.python.org/moin/GoogleGroupsPython.
>>>
>>>
>>> it takes about 20sec i need 5 to 10 times less than that.
>> size = 50mb
>>
>
> Most of the time is spent figuring out whether the file has reached its
> limit size. If you want Python to go fast, just specify the data. On
> my Linux system, it takes 11 seconds to write the first 6338888 values,
> which is just under 50mb. If I write the obvious loop, writing that
> many values takes .25 seconds.
>
> --
> DaveA
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From steve+comp.lang.python at pearwood.info  Fri May 17 12:42:55 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 17 May 2013 16:42:55 GMT
Subject: How to write fast into a file in python?
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
Message-ID: <51965e0e$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 17 May 2013 18:20:33 +0300, Carlos Nepomuceno wrote:

> I've got the following results on my desktop PC (Win7/Python2.7.5):
> 
> C:\src\Python>python -m timeit -cvn3 -r3 "execfile('fastwrite2.py')" raw
> times: 123 126 125
> 3 loops, best of 3: 41 sec per loop

Your times here are increased significantly by using execfile. Using 
execfile means that instead of compiling the code once, then executing 
many times, it gets compiled over and over and over and over again. In my 
experience, using exec, execfile or eval makes your code ten or twenty 
times slower:

[steve at ando ~]$ python -m timeit 'x = 100; y = x/3'
1000000 loops, best of 3: 0.175 usec per loop
[steve at ando ~]$ python -m timeit 'exec("x = 100; y = x/3")'
10000 loops, best of 3: 37.8 usec per loop


> Strangely I just realised that the time it takes to complete such
> scripts is the same no matter what hard drive I choose to run them. The
> results are the same for an SSD (main drive) and a HDD.

There's nothing strange here. The time you measure is dominated by three 
things, in reducing order of importance:

* the poor choice of execfile dominates the time taken; 

* followed by choice of algorithm;

* followed by the time it actually takes to write to the disk, which is 
probably insignificant compared to the other two, regardless of whether 
you are using a HDD or SSD.

Until you optimize the code, optimizing the media is a waste of time. 


> I think it's very strange to take 11.3s to write 50MB (4.4MB/s)
> sequentially on a SSD which is capable of 140MB/s.

It doesn't. It takes 11.3 seconds to open a file, read it into memory, 
parse it, compile it into byte-code, and only then execute it. My 
prediction is that the call to f.write() and f.close() probably take a 
fraction of a second, and nearly all of the rest of the time is taken by 
other calculations.



-- 
Steven


From carlosnepomuceno at outlook.com  Fri May 17 13:25:37 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 17 May 2013 20:25:37 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <51965e0e$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	<51961B73.2070401@davea.name>,
	<mailman.1785.1368804103.3114.python-list@python.org>,
	<51965e0e$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <BLU176-W3508485C6EFEE8661F5B34D7AC0@phx.gbl>

Thank you Steve! You are totally right!

It takes about 0.2s for the f.write() to return. Certainly because it writes to the system file cache (~250MB/s).

Using a little bit different approach I've got:

C:\src\Python>python -m timeit -cvn3 -r3 -s"from fastwrite5r import run" "run()"
raw times: 24 25.1 24.4
3 loops, best of 3: 8 sec per loop
??? 

This time it took 8s to complete from previous 11.3s.

Does those 3.3s are the time to "open, read, parse, compile" steps you told me?

If so, the execute step is really taking 8s, right?

Why does it take so long to build the string to be written? Can it get faster?

Thanks in advance!



### fastwrite5r.py ###
def run():
??? import cStringIO
??? size = 50*1024*1024
??? value = 0
??? filename = 'fastwrite5.dat'
??? x = 0
??? b = cStringIO.StringIO()
??? while x < size:
??????? line = '{0}\n'.format(value)
??????? b.write(line)
??????? value += 1
??????? x += len(line)+1
??? f = open(filename, 'w')
??? f.write(b.getvalue())
??? f.close()
??? b.close()

if __name__ == '__main__':
??? run()





----------------------------------------
> From: steve+comp.lang.python at pearwood.info
> Subject: Re: How to write fast into a file in python?
> Date: Fri, 17 May 2013 16:42:55 +0000
> To: python-list at python.org
>
> On Fri, 17 May 2013 18:20:33 +0300, Carlos Nepomuceno wrote:
>
>> I've got the following results on my desktop PC (Win7/Python2.7.5):
>>
>> C:\src\Python>python -m timeit -cvn3 -r3 "execfile('fastwrite2.py')" raw
>> times: 123 126 125
>> 3 loops, best of 3: 41 sec per loop
>
> Your times here are increased significantly by using execfile. Using
> execfile means that instead of compiling the code once, then executing
> many times, it gets compiled over and over and over and over again. In my
> experience, using exec, execfile or eval makes your code ten or twenty
> times slower:
>
> [steve at ando ~]$ python -m timeit 'x = 100; y = x/3'
> 1000000 loops, best of 3: 0.175 usec per loop
> [steve at ando ~]$ python -m timeit 'exec("x = 100; y = x/3")'
> 10000 loops, best of 3: 37.8 usec per loop
>
>
>> Strangely I just realised that the time it takes to complete such
>> scripts is the same no matter what hard drive I choose to run them. The
>> results are the same for an SSD (main drive) and a HDD.
>
> There's nothing strange here. The time you measure is dominated by three
> things, in reducing order of importance:
>
> * the poor choice of execfile dominates the time taken;
>
> * followed by choice of algorithm;
>
> * followed by the time it actually takes to write to the disk, which is
> probably insignificant compared to the other two, regardless of whether
> you are using a HDD or SSD.
>
> Until you optimize the code, optimizing the media is a waste of time.
>
>
>> I think it's very strange to take 11.3s to write 50MB (4.4MB/s)
>> sequentially on a SSD which is capable of 140MB/s.
>
> It doesn't. It takes 11.3 seconds to open a file, read it into memory,
> parse it, compile it into byte-code, and only then execute it. My
> prediction is that the call to f.write() and f.close() probably take a
> fraction of a second, and nearly all of the rest of the time is taken by
> other calculations.
>
>
>
> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From steve+comp.lang.python at pearwood.info  Fri May 17 13:47:02 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 17 May 2013 17:47:02 GMT
Subject: How to write fast into a file in python?
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
Message-ID: <51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 17 May 2013 18:20:33 +0300, Carlos Nepomuceno wrote:

> ### fastwrite5.py ###
> import cStringIO
> size = 50*1024*1024
> value = 0
> filename = 'fastwrite5.dat'
> x = 0
> b = cStringIO.StringIO()
> while x < size:
> ??? line = '{0}\n'.format(value)
> ??? b.write(line)
> ??? value += 1
> ??? x += len(line)+1

Oh, I forgot to mention: you have a bug in this function. You're already 
including the newline in the len(line), so there is no need to add one. 
The result is that you only generate 44MB instead of 50MB.

> f = open(filename, 'w')
> f.write(b.getvalue())
> f.close()
> b.close()

Here are the results of profiling the above on my computer. Including the 
overhead of the profiler, it takes just over 50 seconds to run your file
on my computer.

[steve at ando ~]$ python -m cProfile fastwrite5.py
         17846645 function calls in 53.575 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1   30.561   30.561   53.575   53.575 fastwrite5.py:1(<module>)
        1    0.000    0.000    0.000    0.000 {cStringIO.StringIO}
  5948879    5.582    0.000    5.582    0.000 {len}
        1    0.004    0.004    0.004    0.004 {method 'close' of 'cStringIO.StringO' objects}
        1    0.000    0.000    0.000    0.000 {method 'close' of 'file' objects}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
  5948879    9.979    0.000    9.979    0.000 {method 'format' of 'str' objects}
        1    0.103    0.103    0.103    0.103 {method 'getvalue' of 'cStringIO.StringO' objects}
  5948879    7.135    0.000    7.135    0.000 {method 'write' of 'cStringIO.StringO' objects}
        1    0.211    0.211    0.211    0.211 {method 'write' of 'file' objects}
        1    0.000    0.000    0.000    0.000 {open}


As you can see, the time is dominated by repeatedly calling len(), 
str.format() and StringIO.write() methods. Actually writing the data to 
the file is quite a small percentage of the cumulative time.

So, here's another version, this time using a pre-calculated limit. I 
cheated and just copied the result from the fastwrite5 output :-)

# fasterwrite.py
filename = 'fasterwrite.dat'
with open(filename, 'w') as f:
    for i in xrange(5948879):  # Actually only 44MB, not 50MB.
        f.write('%d\n' % i)


And the profile results are about twice as fast as fastwrite5 above, with 
only 8 seconds in total writing to my HDD.

[steve at ando ~]$ python -m cProfile fasterwrite.py
         5948882 function calls in 28.840 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1   20.592   20.592   28.840   28.840 fasterwrite.py:1(<module>)
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
  5948879    8.229    0.000    8.229    0.000 {method 'write' of 'file' objects}
        1    0.019    0.019    0.019    0.019 {open}


Without the overhead of the profiler, it is a little faster:

[steve at ando ~]$ time python fasterwrite.py

real    0m16.187s
user    0m13.553s
sys     0m0.508s


Although it is still slower than the heavily optimized dd command, 
but not unreasonably slow for a high-level language:

[steve at ando ~]$ time dd if=fasterwrite.dat of=copy.dat
90781+1 records in
90781+1 records out
46479922 bytes (46 MB) copied, 0.737009 seconds, 63.1 MB/s

real    0m0.786s
user    0m0.071s
sys     0m0.595s




-- 
Steven


From carlosnepomuceno at outlook.com  Fri May 17 14:18:15 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 17 May 2013 21:18:15 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	<51961B73.2070401@davea.name>,
	<mailman.1785.1368804103.3114.python-list@python.org>,
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <BLU176-W301A7BAE8B29C970655AB2D7AC0@phx.gbl>

You've hit the bullseye! ;)

Thanks a lot!!!

> Oh, I forgot to mention: you have a bug in this function. You're already
> including the newline in the len(line), so there is no need to add one.
> The result is that you only generate 44MB instead of 50MB.

That's because I'm running on Windows.
What's the fastest way to check if '\n' translates to 2 bytes on file?

> Here are the results of profiling the above on my computer. Including the
> overhead of the profiler, it takes just over 50 seconds to run your file
> on my computer.
>
> [steve at ando ~]$ python -m cProfile fastwrite5.py
> 17846645 function calls in 53.575 seconds
>

Didn't know the cProfile module.Thanks a lot!

> Ordered by: standard name
>
> ncalls tottime percall cumtime percall filename:lineno(function)
> 1 30.561 30.561 53.575 53.575 fastwrite5.py:1(<module>)
> 1 0.000 0.000 0.000 0.000 {cStringIO.StringIO}
> 5948879 5.582 0.000 5.582 0.000 {len}
> 1 0.004 0.004 0.004 0.004 {method 'close' of 'cStringIO.StringO' objects}
> 1 0.000 0.000 0.000 0.000 {method 'close' of 'file' objects}
> 1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}
> 5948879 9.979 0.000 9.979 0.000 {method 'format' of 'str' objects}
> 1 0.103 0.103 0.103 0.103 {method 'getvalue' of 'cStringIO.StringO' objects}
> 5948879 7.135 0.000 7.135 0.000 {method 'write' of 'cStringIO.StringO' objects}
> 1 0.211 0.211 0.211 0.211 {method 'write' of 'file' objects}
> 1 0.000 0.000 0.000 0.000 {open}
>
>
> As you can see, the time is dominated by repeatedly calling len(),
> str.format() and StringIO.write() methods. Actually writing the data to
> the file is quite a small percentage of the cumulative time.
>
> So, here's another version, this time using a pre-calculated limit. I
> cheated and just copied the result from the fastwrite5 output :-)
>
> # fasterwrite.py
> filename = 'fasterwrite.dat'
> with open(filename, 'w') as f:
> for i in xrange(5948879): # Actually only 44MB, not 50MB.
> f.write('%d\n' % i)
>

I had the same idea but kept the original method because I didn't want to waste time creating a function for calculating the actual number of iterations needed to deliver 50MB of data. ;)

> And the profile results are about twice as fast as fastwrite5 above, with
> only 8 seconds in total writing to my HDD.
>
> [steve at ando ~]$ python -m cProfile fasterwrite.py
> 5948882 function calls in 28.840 seconds
>
> Ordered by: standard name
>
> ncalls tottime percall cumtime percall filename:lineno(function)
> 1 20.592 20.592 28.840 28.840 fasterwrite.py:1(<module>)
> 1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}
> 5948879 8.229 0.000 8.229 0.000 {method 'write' of 'file' objects}
> 1 0.019 0.019 0.019 0.019 {open}
>

I thought there would be a call to format method by "'%d\n' % i". It seems the % operator is a lot faster than format.
I just stopped using it because I read it was going to be deprecated. :(
Why replace such a great and fast operator by a slow method? I mean, why format is been preferred over %?

> Without the overhead of the profiler, it is a little faster:
>
> [steve at ando ~]$ time python fasterwrite.py
>
> real 0m16.187s
> user 0m13.553s
> sys 0m0.508s
>
>
> Although it is still slower than the heavily optimized dd command,
> but not unreasonably slow for a high-level language:
>
> [steve at ando ~]$ time dd if=fasterwrite.dat of=copy.dat
> 90781+1 records in
> 90781+1 records out
> 46479922 bytes (46 MB) copied, 0.737009 seconds, 63.1 MB/s
>
> real 0m0.786s
> user 0m0.071s
> sys 0m0.595s
>
>
>
>
> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From carlosnepomuceno at outlook.com  Fri May 17 14:33:23 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 17 May 2013 21:33:23 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	<51961B73.2070401@davea.name>,
	<mailman.1785.1368804103.3114.python-list@python.org>,
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>

Think the following update will make the code more portable:

x += len(line)+len(os.linesep)-1

Not sure if it's the fastest way to achieve that. :/

> On Fri, 17 May 2013 18:20:33 +0300, Carlos Nepomuceno wrote:
>
>> ### fastwrite5.py ###
>> import cStringIO
>> size = 50*1024*1024
>> value = 0
>> filename = 'fastwrite5.dat'
>> x = 0
>> b = cStringIO.StringIO()
>> while x < size:
>>     line = '{0}\n'.format(value)
>>     b.write(line)
>>     value += 1
>>     x += len(line)+1
>
> Oh, I forgot to mention: you have a bug in this function. You're already
> including the newline in the len(line), so there is no need to add one.
> The result is that you only generate 44MB instead of 50MB. 		 	   		  

From fabiosantosart at gmail.com  Sat May 18 03:49:55 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sat, 18 May 2013 08:49:55 +0100
Subject: How to write fast into a file in python?
In-Reply-To: <BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>
Message-ID: <CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>

On 17 May 2013 19:38, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
wrote:
>
> Think the following update will make the code more portable:
>
> x += len(line)+len(os.linesep)-1
>
> Not sure if it's the fastest way to achieve that. :/
>

Putting len(os.linesep)'s value into a local variable will make accessing
it quite a bit faster. But why would you want to do that?

You mentioned "\n" translating to two lines, but this won't happen. Windows
will not mess with what you write to your file. It's just that
traditionally windows and windows programs use \r\n instead of just \n. I
think it was for compatibility with os/2 or macintosh (I don't remember
which), which used \r for newlines.

You don't have to follow this convention. If you open a \n-separated file
with *any* text editor other than notepad, your newlines will be okay.
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From rosuav at gmail.com  Sat May 18 10:29:50 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 19 May 2013 00:29:50 +1000
Subject: How to write fast into a file in python?
In-Reply-To: <CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>
	<CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>
Message-ID: <CAPTjJmqerFtarnw0F0wj1ydxRHGcWeviKq+o4mautCzqzB-+oA@mail.gmail.com>

On Sat, May 18, 2013 at 5:49 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
> Putting len(os.linesep)'s value into a local variable will make accessing it
> quite a bit faster. But why would you want to do that?
>
> You mentioned "\n" translating to two lines, but this won't happen. Windows
> will not mess with what you write to your file. It's just that traditionally
> windows and windows programs use \r\n instead of just \n. I think it was for
> compatibility with os/2 or macintosh (I don't remember which), which used \r
> for newlines.
>
> You don't have to follow this convention. If you open a \n-separated file
> with *any* text editor other than notepad, your newlines will be okay.


Into two characters, not two lines, but yes. A file opened in text
mode on Windows will have its lines terminated with two characters.
(And it's old Macs that used to use \r. OS/2 follows the DOS
convention of \r\n, but again, many apps these days are happy with
Unix newlines there too.)

ChrisA


From carlosnepomuceno at outlook.com  Sat May 18 13:00:06 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 18 May 2013 20:00:06 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	<51961B73.2070401@davea.name>,
	<mailman.1785.1368804103.3114.python-list@python.org>,
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>,
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>,
	<CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>
Message-ID: <BLU176-W303DF2506F44AF346FCC58D7AD0@phx.gbl>

Python really writes '\n\r' on Windows. Just check the files.

Internal representations only keep '\n' for simplicity, but if you wanna keep track of the file length you have to take that into account. ;)

________________________________
> Date: Sat, 18 May 2013 08:49:55 +0100 
> Subject: RE: How to write fast into a file in python? 
> From: fabiosantosart at gmail.com 
> To: carlosnepomuceno at outlook.com 
> CC: python-list at python.org 
>  
>  
> On 17 May 2013 19:38, "Carlos Nepomuceno"  
> <carlosnepomuceno at outlook.com<mailto:carlosnepomuceno at outlook.com>>  
> wrote: 
> > 
> > Think the following update will make the code more portable: 
> > 
> > x += len(line)+len(os.linesep)-1 
> > 
> > Not sure if it's the fastest way to achieve that. :/ 
> > 
>  
> Putting len(os.linesep)'s value into a local variable will make  
> accessing it quite a bit faster. But why would you want to do that? 
>  
> You mentioned "\n" translating to two lines, but this won't happen.  
> Windows will not mess with what you write to your file. It's just that  
> traditionally windows and windows programs use \r\n instead of just \n.  
> I think it was for compatibility with os/2 or macintosh (I don't  
> remember which), which used \r for newlines. 
>  
> You don't have to follow this convention. If you open a \n-separated  
> file with *any* text editor other than notepad, your newlines will be  
> okay. 		 	   		  

From davea at davea.name  Sat May 18 22:41:32 2013
From: davea at davea.name (Dave Angel)
Date: Sat, 18 May 2013 22:41:32 -0400
Subject: How to write fast into a file in python?
In-Reply-To: <BLU176-W303DF2506F44AF346FCC58D7AD0@phx.gbl>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	<51961B73.2070401@davea.name>,
	<mailman.1785.1368804103.3114.python-list@python.org>,
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>,
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>,
	<CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>
	<BLU176-W303DF2506F44AF346FCC58D7AD0@phx.gbl>
Message-ID: <51983BDC.1060203@davea.name>

On 05/18/2013 01:00 PM, Carlos Nepomuceno wrote:
> Python really writes '\n\r' on Windows. Just check the files.

That's backwards.  '\r\n' on Windows, IF you omit the b in the mode when 
creating the file.



-- 
DaveA


From carlosnepomuceno at outlook.com  Sat May 18 23:53:02 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 19 May 2013 06:53:02 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <51983BDC.1060203@davea.name>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>, ,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>, ,
	<51961B73.2070401@davea.name>, ,
	<mailman.1785.1368804103.3114.python-list@python.org>, ,
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>, ,
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>, ,
	<CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>,
	<BLU176-W303DF2506F44AF346FCC58D7AD0@phx.gbl>,
	<51983BDC.1060203@davea.name>
Message-ID: <BLU176-W35BD1A94FE7FF9DBB1C080D7AE0@phx.gbl>

----------------------------------------
> Date: Sat, 18 May 2013 22:41:32 -0400
> From: davea at davea.name
> To: python-list at python.org
> Subject: Re: How to write fast into a file in python?
>
> On 05/18/2013 01:00 PM, Carlos Nepomuceno wrote:
>> Python really writes '\n\r' on Windows. Just check the files.
>
> That's backwards. '\r\n' on Windows, IF you omit the b in the mode when
> creating the file.

Indeed! My mistake just made me find out that Acorn used that inversion on Acorn MOS.

According to this[1] (at page 449) the OSNEWL routine outputs '\n\r'.

What the hell those guys were thinking??? :p

"OSNEWL
This call issues an LF CR (line feed, carriage return) to the currently selected
output stream. The routine is entered at &FFE7."

[1] http://regregex.bbcmicro.net/BPlusUserGuide-1.07.pdf 		 	   		  

From python at mrabarnett.plus.com  Sun May 19 11:44:55 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 19 May 2013 16:44:55 +0100
Subject: How to write fast into a file in python?
In-Reply-To: <BLU176-W35BD1A94FE7FF9DBB1C080D7AE0@phx.gbl>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>, ,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>, ,
	<51961B73.2070401@davea.name>, ,
	<mailman.1785.1368804103.3114.python-list@python.org>, ,
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>, ,
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>, ,
	<CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>,
	<BLU176-W303DF2506F44AF346FCC58D7AD0@phx.gbl>,
	<51983BDC.1060203@davea.name>
	<BLU176-W35BD1A94FE7FF9DBB1C080D7AE0@phx.gbl>
Message-ID: <5198F377.1050203@mrabarnett.plus.com>

On 19/05/2013 04:53, Carlos Nepomuceno wrote:
> ----------------------------------------
>> Date: Sat, 18 May 2013 22:41:32 -0400
>> From: davea at davea.name
>> To: python-list at python.org
>> Subject: Re: How to write fast into a file in python?
>>
>> On 05/18/2013 01:00 PM, Carlos Nepomuceno wrote:
>>> Python really writes '\n\r' on Windows. Just check the files.
>>
>> That's backwards. '\r\n' on Windows, IF you omit the b in the mode when
>> creating the file.
>
> Indeed! My mistake just made me find out that Acorn used that inversion on Acorn MOS.
>
> According to this[1] (at page 449) the OSNEWL routine outputs '\n\r'.
>
> What the hell those guys were thinking??? :p
>
Doing it that way saved a few bytes.

Code was something like this:

FFE3    .OSASCI CMP #&0D
FFE5            BNE OSWRCH
FFE7    .OSNEWL LDA #&0A
FFE9            JSR OSWRCH
FFEC            LDA #&0D
FFEE    .OSWRCH ...

This means that the contents of the accumulator would always be
preserved by a call to OSASCI.

> "OSNEWL
> This call issues an LF CR (line feed, carriage return) to the currently selected
> output stream. The routine is entered at &FFE7."
>
> [1] http://regregex.bbcmicro.net/BPlusUserGuide-1.07.pdf 		 	   		
>



From carlosnepomuceno at outlook.com  Mon May 20 06:34:56 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 20 May 2013 13:34:56 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <5198F377.1050203@mrabarnett.plus.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	,,<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	,,<51961B73.2070401@davea.name>,
	,,<mailman.1785.1368804103.3114.python-list@python.org>,
	,,<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>,
	,,<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>,
	, , <CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>,
	, <BLU176-W303DF2506F44AF346FCC58D7AD0@phx.gbl>, ,
	<51983BDC.1060203@davea.name>,
	<BLU176-W35BD1A94FE7FF9DBB1C080D7AE0@phx.gbl>,
	<5198F377.1050203@mrabarnett.plus.com>
Message-ID: <BLU176-W4509AF70674F0B94CA38DDD7AF0@phx.gbl>

Oh well! Just got a flashback from the old times at the 8-bit assembly line.

Dirty deeds done dirt cheap! lol

----------------------------------------
> Date: Sun, 19 May 2013 16:44:55 +0100
> From: python at mrabarnett.plus.com
> To: python-list at python.org
> Subject: Re: How to write fast into a file in python?
>
> On 19/05/2013 04:53, Carlos Nepomuceno wrote:
>> ----------------------------------------
>>> Date: Sat, 18 May 2013 22:41:32 -0400
>>> From: davea at davea.name
>>> To: python-list at python.org
>>> Subject: Re: How to write fast into a file in python?
>>>
>>> On 05/18/2013 01:00 PM, Carlos Nepomuceno wrote:
>>>> Python really writes '\n\r' on Windows. Just check the files.
>>>
>>> That's backwards. '\r\n' on Windows, IF you omit the b in the mode when
>>> creating the file.
>>
>> Indeed! My mistake just made me find out that Acorn used that inversion on Acorn MOS.
>>
>> According to this[1] (at page 449) the OSNEWL routine outputs '\n\r'.
>>
>> What the hell those guys were thinking??? :p
>>
> Doing it that way saved a few bytes.
>
> Code was something like this:
>
> FFE3 .OSASCI CMP #&0D
> FFE5 BNE OSWRCH
> FFE7 .OSNEWL LDA #&0A
> FFE9 JSR OSWRCH
> FFEC LDA #&0D
> FFEE .OSWRCH ...
>
> This means that the contents of the accumulator would always be
> preserved by a call to OSASCI.
>
>> "OSNEWL
>> This call issues an LF CR (line feed, carriage return) to the currently selected
>> output stream. The routine is entered at &FFE7."
>>
>> [1] http://regregex.bbcmicro.net/BPlusUserGuide-1.07.pdf
>>
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From roy at panix.com  Sat May 18 15:37:06 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 18 May 2013 15:37:06 -0400
Subject: How to write fast into a file in python?
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>
	<CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>
	<mailman.1813.1368904489.3114.python-list@python.org>
Message-ID: <roy-4604ED.15370618052013@news.panix.com>

In article <mailman.1813.1368904489.3114.python-list at python.org>,
 Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:

> tOn Sat, 18 May 2013 08:49:55 +0100, F?bio Santos
> <fabiosantosart at gmail.com> declaimed the following in
> gmane.comp.python.general:
> 
> 
> > You mentioned "\n" translating to two lines, but this won't happen. Windows
> > will not mess with what you write to your file. It's just that
> > traditionally windows and windows programs use \r\n instead of just \n. I
> > think it was for compatibility with os/2 or macintosh (I don't remember
> > which), which used \r for newlines.
> >
> 	Neither... It goes back to Teletype machines where one sent a
> carriage return to move the printhead back to the left, then sent a line
> feed to advance the paper (while the head was still moving left), and in
> some cases also provided a rub-out character (a do-nothing) to add an
> additional character time delay.

The delay was important.  It took more than one character time for the 
print head to get back to the left margin.  If you kept sending 
printable characters while the print head was still flying back, they 
would get printed in the middle of the line (perhaps blurred a little).

There was also a dashpot which cushioned the head assembly when it 
reached the left margin.  Depending on how well adjusted things were 
this might take another character time or two to fully settle down.

You can still see the remnants of this in modern Unix systems:

$ stty -a
speed 9600 baud; rows 40; columns 136; line = 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = M-^?; eol2 
= M-^?; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z;
rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-parenb -parodd cs8 -hupcl -cstopb cread -clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon 
-ixoff -iuclc ixany imaxbel -iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 
vt0 ff0
isig icanon iexten echo echoe -echok -echonl -noflsh -xcase -tostop 
-echoprt echoctl echoke

The "nl0" and "cr0" mean it's configured to insert 0 delay after 
newlines and carriage returns.  Whether setting a non-zero delay 
actually does anything useful anymore is an open question, but the 
drivers still accept the settings.


From steve+comp.lang.python at pearwood.info  Sat May 18 18:23:31 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 18 May 2013 22:23:31 GMT
Subject: How to write fast into a file in python?
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>
	<CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>
	<mailman.1813.1368904489.3114.python-list@python.org>
Message-ID: <5197ff62$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sat, 18 May 2013 15:14:31 -0400, Dennis Lee Bieber wrote:

> tOn Sat, 18 May 2013 08:49:55 +0100, F?bio Santos
> <fabiosantosart at gmail.com> declaimed the following in
> gmane.comp.python.general:
> 
> 
>> You mentioned "\n" translating to two lines, but this won't happen.
>> Windows will not mess with what you write to your file. 

Windows certainly may mess with what you write to your file, if it is 
opened in Text mode instead of Binary mode. In text mode, Windows will:

- interpret Ctrl-Z characters as End Of File when reading;

- convert \r\n to \n when reading;

- convert \n to \r\n when writing.

http://msdn.microsoft.com/en-us/library/z5hh6ee9(v=vs.80).aspx


>> It's just that
>> traditionally windows and windows programs use \r\n instead of just \n.
>> I think it was for compatibility with os/2 or macintosh (I don't
>> remember which), which used \r for newlines.
>>
> 	Neither... It goes back to Teletype machines where one sent a
> carriage return to move the printhead back to the left, then sent a line
> feed to advance the paper (while the head was still moving left), and in
> some cases also provided a rub-out character (a do-nothing) to add an
> additional character time delay.

Yes, if you go back far enough, you get to teletype machines. But Windows 
inherits its text-mode behaviour from DOS, which inherits it from CP/M. 


> 	TRS-80 Mod 1-4 used <cr> for "new line", I believe Apple used <lf>
> for "new line"... 

I can't comment about TRS, but classic Apple Macs (up to System 9) used 
carriage return \r as the line separator.



-- 
Steven


From fabiosantosart at gmail.com  Sat May 18 17:19:54 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sat, 18 May 2013 22:19:54 +0100
Subject: How to write fast into a file in python?
In-Reply-To: <hbkfp8dg7nlp08ticsv6gkmmt7k94c1od4@invalid.netcom.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>
	<CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>
	<hbkfp8dg7nlp08ticsv6gkmmt7k94c1od4@invalid.netcom.com>
Message-ID: <CAA=1kxRfhDz2KC5bGtZ0pHLF75bDPpK5Y61VuXvELoTbb8ktiw@mail.gmail.com>

On 18 May 2013 20:19, "Dennis Lee Bieber" <wlfraed at ix.netcom.com> wrote:
>
> tOn Sat, 18 May 2013 08:49:55 +0100, F?bio Santos
> <fabiosantosart at gmail.com> declaimed the following in
> gmane.comp.python.general:
>
>
> > You mentioned "\n" translating to two lines, but this won't happen. Windows
> > will not mess with what you write to your file. It's just that
> > traditionally windows and windows programs use \r\n instead of just \n. I
> > think it was for compatibility with os/2 or macintosh (I don't remember
> > which), which used \r for newlines.
> >
>         Neither... It goes back to Teletype machines where one sent a
> carriage return to move the printhead back to the left, then sent a line
> feed to advance the paper (while the head was still moving left), and in
> some cases also provided a rub-out character (a do-nothing) to add an
> additional character time delay.
>
>         TRS-80 Mod 1-4 used <cr> for "new line", I believe Apple used <lf>
> for "new line"... And both lost the ability to move down the page
> without also resetting the carriage to the left. In a world where both
> <cr><lf> is used, one could draw a vertical line of | by just spacing
> across the first line, printing |, then repeat <lf><bkspc>| until done.
> To do the same with conventional <lf> is "new line/return" one has to
> transmit all those spaces for each line...
>
>         At 300baud, that took time....



On Sat, May 18, 2013 at 6:00 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> Python really writes '\n\r' on Windows. Just check the files.
>
> Internal representations only keep '\n' for simplicity, but if you wanna keep track of the file length you have to take that into account. ;)


On Sat, May 18, 2013 at 3:29 PM, Chris Angelico <rosuav at gmail.com> wrote:
> Into two characters, not two lines, but yes. A file opened in text
> mode on Windows will have its lines terminated with two characters.
> (And it's old Macs that used to use \r. OS/2 follows the DOS
> convention of \r\n, but again, many apps these days are happy with
> Unix newlines there too.)
>
> ChrisA

Thanks for your corrections and explanations. I stand corrected and
have learned something.


From timr at probo.com  Sun May 19 22:04:17 2013
From: timr at probo.com (Tim Roberts)
Date: Sun, 19 May 2013 19:04:17 -0700
Subject: How to write fast into a file in python?
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	<51961B73.2070401@davea.name>,
	<mailman.1785.1368804103.3114.python-list@python.org>,
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>,
	<BLU176-W2D076D16CF4457F289E40D7AC0@phx.gbl>,
	<CAA=1kxRK3F3_gYGEecRkHS33e5nEHa1KQqAK0BeODty0RqJH5A@mail.gmail.com>
	<mailman.1808.1368896475.3114.python-list@python.org>
Message-ID: <h21jp8tnkucskbpugr7bb41m41h902o8rq@4ax.com>

Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:

>Python really writes '\n\r' on Windows. Just check the files.

It actually writes \r\n, but it's not Python that's doing it.  It's the C
runtime library.

And, of course, you can eliminate all of that by opening the file in binary
mode open(name,'wb').
-- 
Tim Roberts, timr at probo.com
Providenza & Boekelheide, Inc.


From steve+comp.lang.python at pearwood.info  Sat May 18 00:01:13 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 18 May 2013 04:01:13 GMT
Subject: How to write fast into a file in python?
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1788.1368814763.3114.python-list@python.org>
Message-ID: <5196fd08$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Fri, 17 May 2013 21:18:15 +0300, Carlos Nepomuceno wrote:

> I thought there would be a call to format method by "'%d\n' % i". It
> seems the % operator is a lot faster than format. I just stopped using
> it because I read it was going to be deprecated. :( Why replace such a
> great and fast operator by a slow method? I mean, why format is been
> preferred over %?

That is one of the most annoying, pernicious myths about Python, probably 
second only to "the GIL makes Python slow" (it actually makes it fast). 

String formatting with % is not deprecated. It will not be deprecated, at 
least not until Python 4000.

The string format() method has a few advantages: it is more powerful, 
consistent and flexible, but it is significantly slower.

Probably the biggest disadvantage to % formatting, and probably the main 
reason why it is "discouraged", is that it treats tuples specially. 
Consider if x is an arbitrary object, and you call "%s" % x:

py> "%s" % 23  # works
'23'
py> "%s" % [23, 42]  # works
'[23, 42]'

and so on for *almost* any object. But if x is a tuple, strange things 
happen:

py> "%s" % (23,)  # tuple with one item looks like an int
'23'
py> "%s" % (23, 42)  # tuple with two items fails
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: not all arguments converted during string formatting


So when dealing with arbitrary objects that you cannot predict what they 
are, it is better to use format.



-- 
Steven


From rosuav at gmail.com  Sat May 18 01:28:08 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 18 May 2013 15:28:08 +1000
Subject: How to write fast into a file in python?
In-Reply-To: <5196fd08$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1788.1368814763.3114.python-list@python.org>
	<5196fd08$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmrmh8dwrGN0SMQ92Gm=dAR2Q5myn=mcaZWtYbzERKsteQ@mail.gmail.com>

On Sat, May 18, 2013 at 2:01 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Consider if x is an arbitrary object, and you call "%s" % x:
>
> py> "%s" % 23  # works
> '23'
> py> "%s" % [23, 42]  # works
> '[23, 42]'
>
> and so on for *almost* any object. But if x is a tuple, strange things
> happen

Which can be guarded against by wrapping it up in a tuple. All you're
seeing is that the shortcut notation for a single parameter can't
handle tuples.

>>> def show(x):
	return "%s" % (x,)

>>> show(23)
'23'
>>> show((23,))
'(23,)'
>>> show([23,42])
'[23, 42]'

One of the biggest differences between %-formatting and str.format is
that one is an operator and the other a method. The operator is always
going to be faster, but the method can give more flexibility (not that
I've ever needed or wanted to override anything).

>>> def show_format(x):
	return "{}".format(x) # Same thing using str.format
>>> dis.dis(show)
  2           0 LOAD_CONST               1 ('%s')
              3 LOAD_FAST                0 (x)
              6 BUILD_TUPLE              1
              9 BINARY_MODULO
             10 RETURN_VALUE
>>> dis.dis(show_format)
  2           0 LOAD_CONST               1 ('{}')
              3 LOAD_ATTR                0 (format)
              6 LOAD_FAST                0 (x)
              9 CALL_FUNCTION            1 (1 positional, 0 keyword pair)
             12 RETURN_VALUE

Attribute lookup and function call versus binary operator. Potentially
a lot of flexibility, versus basically hard-coded functionality. But
has anyone ever actually made use of it?

str.format does have some cleaner features, like naming of parameters:

>>> "{foo} vs {bar}".format(foo=1,bar=2)
'1 vs 2'
>>> "%(foo)s vs %(bar)s"%{'foo':1,'bar':2}
'1 vs 2'

Extremely handy when you're working with hugely complex format
strings, and the syntax feels a bit clunky in % (also, it's not
portable to other languages, which is one of %-formatting's biggest
features). Not a huge deal, but if you're doing a lot with that, it
might be a deciding vote.

ChrisA


From dihedral88888 at googlemail.com  Sat May 18 07:09:58 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Sat, 18 May 2013 04:09:58 -0700 (PDT)
Subject: How to write fast into a file in python?
In-Reply-To: <5196fd08$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<51961B73.2070401@davea.name>
	<mailman.1785.1368804103.3114.python-list@python.org>
	<51966d15$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1788.1368814763.3114.python-list@python.org>
	<5196fd08$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <b960d47a-de79-4bc8-b731-328a6405f9cb@googlegroups.com>

Steven D'Aprano? 2013?5?18????UTC+8??12?01?13????
> On Fri, 17 May 2013 21:18:15 +0300, Carlos Nepomuceno wrote:
> 
> 
> 
> > I thought there would be a call to format method by "'%d\n' % i". It
> 
> > seems the % operator is a lot faster than format. I just stopped using
> 
> > it because I read it was going to be deprecated. :( Why replace such a
> 
> > great and fast operator by a slow method? I mean, why format is been
> 
> > preferred over %?
> 
> 
> 
> That is one of the most annoying, pernicious myths about Python, probably 
> 
> second only to "the GIL makes Python slow" (it actually makes it fast). 
> 
> 

The print function in python  is designed to print 
any printable object with a valid string representation.

The format part of the print function has to construct 
a printable string according to the format string 
and the variables passed in on the fly. 

If the acctual string to be printed in the format processing
is obtained in the high level OOP way , then it is definitely 
slow due to the high level overheads and generality requirements.







From drsalists at gmail.com  Sat May 18 15:38:30 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Sat, 18 May 2013 12:38:30 -0700
Subject: How to write fast into a file in python?
In-Reply-To: <87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
Message-ID: <CAGGBd_ot27sFCi_hZkytwpP-M2oyxEtz60v9zLppWsWsLLiFOQ@mail.gmail.com>

With CPython 2.7.3:
./t
time taken to write a file of size 52428800  is  15.86 seconds

time taken to write a file of size 52428800  is  7.91 seconds

time taken to write a file of size 52428800  is  9.64 seconds


With pypy-1.9:
./t
time taken to write a file of size 52428800  is  3.708232 seconds

time taken to write a file of size 52428800  is  4.868304 seconds

time taken to write a file of size 52428800  is  1.93612 seconds


Here's the code:
#!/usr/local/pypy-1.9/bin/pypy
#!/usr/bin/python

import sys
import time
import StringIO

sys.path.insert(0, '/usr/local/lib')
import bufsock

def create_file_numbers_old(filename, size):
    start = time.clock()

    value = 0
    with open(filename, "w") as f:
        while f.tell() < size:
            f.write("{0}\n".format(value))
            value += 1

    end = time.clock()

    print "time taken to write a file of size", size, " is ", (end -start),
"seconds \n"

def create_file_numbers_bufsock(filename, intended_size):
    start = time.clock()

    value = 0
    with open(filename, "w") as f:
        bs = bufsock.bufsock(f)
        actual_size = 0
        while actual_size < intended_size:
            string = "{0}\n".format(value)
            actual_size += len(string) + 1
            bs.write(string)
            value += 1
        bs.flush()

    end = time.clock()

    print "time taken to write a file of size", intended_size, " is ", (end
-start), "seconds \n"


def create_file_numbers_file_like(filename, intended_size):
    start = time.clock()

    value = 0
    with open(filename, "w") as f:
        file_like = StringIO.StringIO()
        actual_size = 0
        while actual_size < intended_size:
            string = "{0}\n".format(value)
            actual_size += len(string) + 1
            file_like.write(string)
            value += 1
        file_like.seek(0)
        f.write(file_like.read())

    end = time.clock()

    print "time taken to write a file of size", intended_size, " is ", (end
-start), "seconds \n"

create_file_numbers_old('output.txt', 50 * 2**20)
create_file_numbers_bufsock('output2.txt', 50 * 2**20)
create_file_numbers_file_like('output3.txt', 50 * 2**20)




On Thu, May 16, 2013 at 9:35 PM, <lokeshkoppaka at gmail.com> wrote:

> On Friday, May 17, 2013 8:50:26 AM UTC+5:30, lokesh... at gmail.com wrote:
> > I need to write numbers into a file upto 50mb and it should be fast
> >
> > can any one help me how to do that?
> >
> > i had written the following code..
> >
> >
> -----------------------------------------------------------------------------------------------------------
> >
> > def create_file_numbers_old(filename, size):
> >
> > start = time.clock()
> >
> >
> >
> > value = 0
> >
> > with open(filename, "w") as f:
> >
> > while f.tell()< size:
> >
> > f.write("{0}\n".format(value))
> >
> > value += 1
> >
> >
> >
> > end = time.clock()
> >
> >
> >
> > print "time taken to write a file of size", size, " is ", (end -start),
> "seconds \n"
> >
> >
> ------------------------------------------------------------------------------------------------------------------
> >
> > it takes about 20sec i need 5 to 10 times less than that.
> size = 50mb
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From carlosnepomuceno at outlook.com  Sun May 19 01:31:08 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 19 May 2013 08:31:08 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <CAGGBd_ot27sFCi_hZkytwpP-M2oyxEtz60v9zLppWsWsLLiFOQ@mail.gmail.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	<CAGGBd_ot27sFCi_hZkytwpP-M2oyxEtz60v9zLppWsWsLLiFOQ@mail.gmail.com>
Message-ID: <BLU176-W441484E62DE499076560DED7AE0@phx.gbl>

Thanks Dan! I've never used CPython or PyPy. Will try them later.

I think the main difference between your create_file_numbers_file_like()
 and the fastwrite5.py I sent earlier is that I've used cStringIO 
instead of StringIO. It took 12s less using cStringIO.

My numbers are much greater, but I've used Python 2.7.5 instead:

C:\src\Python>python create_file_numbers.py
time taken to write a file of size 52428800? is? 39.1199457743 seconds

time taken to write a file of size 52428800? is? 14.8704800436 seconds

time taken to write a file of size 52428800? is? 23.0011990985 seconds


I've downloaded bufsock.py and python2x3.py. The later one was hard to remove the source code from the web page.

Can I use them on my projects? I'm not used to the UCI license[1]. What's the difference to the GPL?




[1] http://stromberg.dnsalias.org/~dstromberg/UCI-license.html

________________________________
> Date: Sat, 18 May 2013 12:38:30 -0700 
> Subject: Re: How to write fast into a file in python? 
> From: drsalists at gmail.com 
> To: lokeshkoppaka at gmail.com 
> CC: python-list at python.org 
>  
>  
> With CPython 2.7.3: 
> ./t 
> time taken to write a file of size 52428800  is  15.86 seconds 
>  
> time taken to write a file of size 52428800  is  7.91 seconds 
>  
> time taken to write a file of size 52428800  is  9.64 seconds 
>  
>  
> With pypy-1.9: 
> ./t 
> time taken to write a file of size 52428800  is  3.708232 seconds 
>  
> time taken to write a file of size 52428800  is  4.868304 seconds 
>  
> time taken to write a file of size 52428800  is  1.93612 seconds 
>  

> Here's the code: 
> #!/usr/local/pypy-1.9/bin/pypy 
> #!/usr/bin/python 
>  
> import sys 
> import time 
> import StringIO 
>  
> sys.path.insert(0, '/usr/local/lib') 
> import bufsock 
>  
> def create_file_numbers_old(filename, size): 
>      start = time.clock() 
>  
>      value = 0 
>      with open(filename, "w") as f: 
>          while f.tell() < size: 
>              f.write("{0}\n".format(value)) 
>              value += 1 
>  
>      end = time.clock() 
>  
>      print "time taken to write a file of size", size, " is ", (end  
> -start), "seconds \n" 
>  
> def create_file_numbers_bufsock(filename, intended_size): 
>      start = time.clock() 
>  
>      value = 0 
>      with open(filename, "w") as f: 
>          bs = bufsock.bufsock(f) 
>          actual_size = 0 
>          while actual_size < intended_size: 
>              string = "{0}\n".format(value) 
>              actual_size += len(string) + 1 
>              bs.write(string) 
>              value += 1 
>          bs.flush() 
>  
>      end = time.clock() 
>  
>      print "time taken to write a file of size", intended_size, " is ",  
> (end -start), "seconds \n" 
>  
>  
> def create_file_numbers_file_like(filename, intended_size): 
>      start = time.clock() 
>  
>      value = 0 
>      with open(filename, "w") as f: 
>          file_like = StringIO.StringIO() 
>          actual_size = 0 
>          while actual_size < intended_size: 
>              string = "{0}\n".format(value) 
>              actual_size += len(string) + 1 
>              file_like.write(string) 
>              value += 1 
>          file_like.seek(0) 
>          f.write(file_like.read()) 
>  
>      end = time.clock() 
>  
>      print "time taken to write a file of size", intended_size, " is ",  
> (end -start), "seconds \n" 
>  
> create_file_numbers_old('output.txt', 50 * 2**20) 
> create_file_numbers_bufsock('output2.txt', 50 * 2**20) 
> create_file_numbers_file_like('output3.txt', 50 * 2**20) 
>  
>  
>  
>  
> On Thu, May 16, 2013 at 9:35 PM,  
> <lokeshkoppaka at gmail.com<mailto:lokeshkoppaka at gmail.com>> wrote: 
> On Friday, May 17, 2013 8:50:26 AM UTC+5:30,  
> lokesh... at gmail.com<mailto:lokesh... at gmail.com> wrote: 
> > I need to write numbers into a file upto 50mb and it should be fast 
> > 
> > can any one help me how to do that? 
> > 
> > i had written the following code.. 
> > 
> >  
> ----------------------------------------------------------------------------------------------------------- 
> > 
> > def create_file_numbers_old(filename, size): 
> > 
> > start = time.clock() 
> > 
> > 
> > 
> > value = 0 
> > 
> > with open(filename, "w") as f: 
> > 
> > while f.tell()< size: 
> > 
> > f.write("{0}\n".format(value)) 
> > 
> > value += 1 
> > 
> > 
> > 
> > end = time.clock() 
> > 
> > 
> > 
> > print "time taken to write a file of size", size, " is ", (end  
> -start), "seconds \n" 
> > 
> >  
> ------------------------------------------------------------------------------------------------------------------ 
> > 
> > it takes about 20sec i need 5 to 10 times less than that. 
> size = 50mb 
> -- 
> http://mail.python.org/mailman/listinfo/python-list 
>  
>  
> -- http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From carlosnepomuceno at outlook.com  Sun May 19 01:42:41 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 19 May 2013 08:42:41 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <BLU176-W441484E62DE499076560DED7AE0@phx.gbl>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>, ,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>, ,
	<CAGGBd_ot27sFCi_hZkytwpP-M2oyxEtz60v9zLppWsWsLLiFOQ@mail.gmail.com>,
	<BLU176-W441484E62DE499076560DED7AE0@phx.gbl>
Message-ID: <BLU176-W29F9CFC06725FC67E6C950D7AE0@phx.gbl>

BTW, I've downloaded from the following places:

http://stromberg.dnsalias.org/svn/bufsock/trunk/bufsock.py
http://stromberg.dnsalias.org/~dstromberg/backshift/documentation/html/python2x3-pysrc.html

Are those the latest versions?

----------------------------------------
> From: carlosnepomuceno at outlook.com
> To: python-list at python.org
> Subject: RE: How to write fast into a file in python?
> Date: Sun, 19 May 2013 08:31:08 +0300
> CC: lokeshkoppaka at gmail.com
>
> Thanks Dan! I've never used CPython or PyPy. Will try them later.
>
> I think the main difference between your create_file_numbers_file_like()
> and the fastwrite5.py I sent earlier is that I've used cStringIO
> instead of StringIO. It took 12s less using cStringIO.
>
> My numbers are much greater, but I've used Python 2.7.5 instead:
>
> C:\src\Python>python create_file_numbers.py
> time taken to write a file of size 52428800  is  39.1199457743 seconds
>
> time taken to write a file of size 52428800  is  14.8704800436 seconds
>
> time taken to write a file of size 52428800  is  23.0011990985 seconds
>
>
> I've downloaded bufsock.py and python2x3.py. The later one was hard to remove the source code from the web page.
>
> Can I use them on my projects? I'm not used to the UCI license[1]. What's the difference to the GPL?
>
>
>
>
> [1] http://stromberg.dnsalias.org/~dstromberg/UCI-license.html
>
> ________________________________
>> Date: Sat, 18 May 2013 12:38:30 -0700
>> Subject: Re: How to write fast into a file in python?
>> From: drsalists at gmail.com
>> To: lokeshkoppaka at gmail.com
>> CC: python-list at python.org
>>
>>
>> With CPython 2.7.3:
>> ./t
>> time taken to write a file of size 52428800 is 15.86 seconds
>>
>> time taken to write a file of size 52428800 is 7.91 seconds
>>
>> time taken to write a file of size 52428800 is 9.64 seconds
>>
>>
>> With pypy-1.9:
>> ./t
>> time taken to write a file of size 52428800 is 3.708232 seconds
>>
>> time taken to write a file of size 52428800 is 4.868304 seconds
>>
>> time taken to write a file of size 52428800 is 1.93612 seconds
>>
>
>> Here's the code:
>> #!/usr/local/pypy-1.9/bin/pypy
>> #!/usr/bin/python
>>
>> import sys
>> import time
>> import StringIO
>>
>> sys.path.insert(0, '/usr/local/lib')
>> import bufsock
>>
>> def create_file_numbers_old(filename, size):
>> start = time.clock()
>>
>> value = 0
>> with open(filename, "w") as f:
>> while f.tell() < size:
>> f.write("{0}\n".format(value))
>> value += 1
>>
>> end = time.clock()
>>
>> print "time taken to write a file of size", size, " is ", (end
>> -start), "seconds \n"
>>
>> def create_file_numbers_bufsock(filename, intended_size):
>> start = time.clock()
>>
>> value = 0
>> with open(filename, "w") as f:
>> bs = bufsock.bufsock(f)
>> actual_size = 0
>> while actual_size < intended_size:
>> string = "{0}\n".format(value)
>> actual_size += len(string) + 1
>> bs.write(string)
>> value += 1
>> bs.flush()
>>
>> end = time.clock()
>>
>> print "time taken to write a file of size", intended_size, " is ",
>> (end -start), "seconds \n"
>>
>>
>> def create_file_numbers_file_like(filename, intended_size):
>> start = time.clock()
>>
>> value = 0
>> with open(filename, "w") as f:
>> file_like = StringIO.StringIO()
>> actual_size = 0
>> while actual_size < intended_size:
>> string = "{0}\n".format(value)
>> actual_size += len(string) + 1
>> file_like.write(string)
>> value += 1
>> file_like.seek(0)
>> f.write(file_like.read())
>>
>> end = time.clock()
>>
>> print "time taken to write a file of size", intended_size, " is ",
>> (end -start), "seconds \n"
>>
>> create_file_numbers_old('output.txt', 50 * 2**20)
>> create_file_numbers_bufsock('output2.txt', 50 * 2**20)
>> create_file_numbers_file_like('output3.txt', 50 * 2**20)
>>
>>
>>
>>
>> On Thu, May 16, 2013 at 9:35 PM,
>> <lokeshkoppaka at gmail.com<mailto:lokeshkoppaka at gmail.com>> wrote:
>> On Friday, May 17, 2013 8:50:26 AM UTC+5:30,
>> lokesh... at gmail.com<mailto:lokesh... at gmail.com> wrote:
>>> I need to write numbers into a file upto 50mb and it should be fast
>>>
>>> can any one help me how to do that?
>>>
>>> i had written the following code..
>>>
>>>
>> -----------------------------------------------------------------------------------------------------------
>>>
>>> def create_file_numbers_old(filename, size):
>>>
>>> start = time.clock()
>>>
>>>
>>>
>>> value = 0
>>>
>>> with open(filename, "w") as f:
>>>
>>> while f.tell()< size:
>>>
>>> f.write("{0}\n".format(value))
>>>
>>> value += 1
>>>
>>>
>>>
>>> end = time.clock()
>>>
>>>
>>>
>>> print "time taken to write a file of size", size, " is ", (end
>> -start), "seconds \n"
>>>
>>>
>> ------------------------------------------------------------------------------------------------------------------
>>>
>>> it takes about 20sec i need 5 to 10 times less than that.
>> size = 50mb
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>>
>>
>> -- http://mail.python.org/mailman/listinfo/python-list
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rosuav at gmail.com  Sun May 19 05:21:54 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 19 May 2013 19:21:54 +1000
Subject: How to write fast into a file in python?
In-Reply-To: <BLU176-W441484E62DE499076560DED7AE0@phx.gbl>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>
	<CAGGBd_ot27sFCi_hZkytwpP-M2oyxEtz60v9zLppWsWsLLiFOQ@mail.gmail.com>
	<BLU176-W441484E62DE499076560DED7AE0@phx.gbl>
Message-ID: <CAPTjJmp9EF8sArk_gGSLxeKJwSeLjVJVCgiZYmZ8f7iEet9oLg@mail.gmail.com>

On Sun, May 19, 2013 at 3:31 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> Thanks Dan! I've never used CPython or PyPy. Will try them later.

CPython is the "classic" interpreter, written in C. It's the one
you'll get from the obvious download links on python.org.

ChrisA


From carlosnepomuceno at outlook.com  Sun May 19 05:41:23 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 19 May 2013 12:41:23 +0300
Subject: How to write fast into a file in python?
In-Reply-To: <CAPTjJmp9EF8sArk_gGSLxeKJwSeLjVJVCgiZYmZ8f7iEet9oLg@mail.gmail.com>
References: <e9dcd255-b892-40a0-ae6b-0995a61a270f@googlegroups.com>,
	<87f9a3d4-427e-472f-bee7-9501ba842b36@googlegroups.com>,
	<CAGGBd_ot27sFCi_hZkytwpP-M2oyxEtz60v9zLppWsWsLLiFOQ@mail.gmail.com>,
	<BLU176-W441484E62DE499076560DED7AE0@phx.gbl>,
	<CAPTjJmp9EF8sArk_gGSLxeKJwSeLjVJVCgiZYmZ8f7iEet9oLg@mail.gmail.com>
Message-ID: <BLU176-W30946B133C3FF5D67C0F35D7AE0@phx.gbl>

ooops! I meant to say Cython. nevermind...

----------------------------------------
> Date: Sun, 19 May 2013 19:21:54 +1000
> Subject: Re: How to write fast into a file in python?
> From: rosuav at gmail.com
> To: python-list at python.org
>
> On Sun, May 19, 2013 at 3:31 PM, Carlos Nepomuceno
> <carlosnepomuceno at outlook.com> wrote:
>> Thanks Dan! I've never used CPython or PyPy. Will try them later.
>
> CPython is the "classic" interpreter, written in C. It's the one
> you'll get from the obvious download links on python.org.
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From diolu.remove_this_part at bigfoot.com  Fri May 17 02:57:04 2013
From: diolu.remove_this_part at bigfoot.com (Olive)
Date: Fri, 17 May 2013 08:57:04 +0200
Subject: Diacretical incensitive search
Message-ID: <20130517085704.3f6609e8@pcolivier.chezmoi.net>

One feature that seems to be missing in the re module (or any tools that I know for searching text) is "diacretical incensitive search". I would like to have a match for something like this:

re.match("franc", "fran?ais")

in about the same whay we can have a case incensitive search:

re.match("(?i)fran", "Fran?ais").

Another related and more general problem (in the sense that it could easily be used to solve the first problem) would be to translate a string removing any diacritical mark:

nodiac("Fran?ais") -> "Francais"

The algorithm to write such a function is trivial but there are a lot of mark we can put on a letter. It would be necessary to have the list of "a"'s with something on it. i.e. "?,?,?", etc. and this for every letter. Trying to make such a list by hand would inevitably lead to some symbols forgotten (and would be tedious). 

Olive




From petite.abeille at gmail.com  Fri May 17 03:15:27 2013
From: petite.abeille at gmail.com (Petite Abeille)
Date: Fri, 17 May 2013 09:15:27 +0200
Subject: Diacretical incensitive search
In-Reply-To: <20130517085704.3f6609e8@pcolivier.chezmoi.net>
References: <20130517085704.3f6609e8@pcolivier.chezmoi.net>
Message-ID: <C9AFA72A-45A9-4263-A1B8-5D7C5D40B3A3@gmail.com>


On May 17, 2013, at 8:57 AM, Olive <diolu.remove_this_part at bigfoot.com> wrote:

> The algorithm to write such a function is trivial but there are a lot of mark we can put on a letter. It would be necessary to have the list of "a"'s with something on it. i.e. "?,?,?", etc. and this for every letter. Trying to make such a list by hand would inevitably lead to some symbols forgotten (and would be tedious). 

Perhaps of interest? Sean M. Burke Unidecode? 

There appear to be several python implementations, e.g.:

https://pypi.python.org/pypi/Unidecode



From __peter__ at web.de  Fri May 17 04:30:04 2013
From: __peter__ at web.de (Peter Otten)
Date: Fri, 17 May 2013 10:30:04 +0200
Subject: Diacretical incensitive search
References: <20130517085704.3f6609e8@pcolivier.chezmoi.net>
Message-ID: <kn4ppp$as$1@ger.gmane.org>

Olive wrote:

> One feature that seems to be missing in the re module (or any tools that I
> know for searching text) is "diacretical incensitive search". I would like
> to have a match for something like this:
> 
> re.match("franc", "fran?ais")
> 
> in about the same whay we can have a case incensitive search:
> 
> re.match("(?i)fran", "Fran?ais").
> 
> Another related and more general problem (in the sense that it could
> easily be used to solve the first problem) would be to translate a string
> removing any diacritical mark:
> 
> nodiac("Fran?ais") -> "Francais"
> 
> The algorithm to write such a function is trivial but there are a lot of
> mark we can put on a letter. It would be necessary to have the list of
> "a"'s with something on it. i.e. "?,?,?", etc. and this for every letter.
> Trying to make such a list by hand would inevitably lead to some symbols
> forgotten (and would be tedious).

[Python3.3]

>>> unicodedata.normalize("NFKD", "Fran?ais").encode("ascii", 
"ignore").decode()
'Francais'

import sys
from collections import defaultdict
from unicodedata import name, normalize

d = defaultdict(list)
for i in range(sys.maxunicode):
    c = chr(i)
    n = normalize("NFKD", c)[0]
    if ord(n) < 128 and n.isalpha(): # optional
        d[n].append(c)

for k, v in d.items():
    if len(v) > 1:
        print(k, "".join(v))

See also <http://effbot.org/zone/unicode-convert.htm>

PS: Be warned that experiments on the console may be misleading:

>>> unicodedata.normalize("NFKD", "?")
'c'
>>> ascii(_)
"'c\\u0327'"




From diolu.remove_this_part at bigfoot.com  Fri May 17 11:37:17 2013
From: diolu.remove_this_part at bigfoot.com (Olive)
Date: Fri, 17 May 2013 17:37:17 +0200
Subject: Diacretical incensitive search
References: <20130517085704.3f6609e8@pcolivier.chezmoi.net>
	<mailman.1783.1368779403.3114.python-list@python.org>
Message-ID: <20130517173717.65f0aa31@pcolivier.chezmoi.net>

Tanks a lot!



From wxjmfauth at gmail.com  Fri May 17 13:31:25 2013
From: wxjmfauth at gmail.com (jmfauth)
Date: Fri, 17 May 2013 10:31:25 -0700 (PDT)
Subject: Diacretical incensitive search
References: <20130517085704.3f6609e8@pcolivier.chezmoi.net>
	<mailman.1783.1368779403.3114.python-list@python.org>
	<20130517173717.65f0aa31@pcolivier.chezmoi.net>
Message-ID: <ef50d7a2-9297-4b19-b1b0-249e86e09678@en2g2000vbb.googlegroups.com>

--------


The handling of diacriticals is especially a nice case
study. One can use it to toy with some specific features of
Unicode, normalisation, decomposition, ...

... and also to show how Unicode can be badly implemented.

First and quick example that came to my mind (Py325 and Py332):

>>> timeit.repeat("ud.normalize('NFKC', ud.normalize('NFKD', '?????'))", "import unicodedata as ud")
[2.929404406789672, 2.923327801150208, 2.923659417064755]

>>> timeit.repeat("ud.normalize('NFKC', ud.normalize('NFKD', '?????'))", "import unicodedata as ud")
[3.8437222586746884, 3.829490737203514, 3.819266963414293]

jmf


From grahn+nntp at snipabacken.se  Mon May 20 05:10:15 2013
From: grahn+nntp at snipabacken.se (Jorgen Grahn)
Date: 20 May 2013 09:10:15 GMT
Subject: Diacretical incensitive search
References: <20130517085704.3f6609e8@pcolivier.chezmoi.net>
Message-ID: <slrnkpjq3m.3jn.grahn+nntp@frailea.sa.invalid>

On Fri, 2013-05-17, Olive wrote:

> One feature that seems to be missing in the re module (or any tools
> that I know for searching text) is "diacretical incensitive search". I
> would like to have a match for something like this:

> re.match("franc", "fran?ais")
...

> The algorithm to write such a function is trivial but there are a
> lot of mark we can put on a letter. It would be necessary to have the
> list of "a"'s with something on it. i.e. "?,?,?", etc. and this for
> every letter. Trying to make such a list by hand would inevitably lead
> to some symbols forgotten (and would be tedious). 

Ok, but please remember that the diacriticals are of varying importance.
The english "na?ve" is easily recognizable when written as "naive".
The swedish word "f?r" cannot be spelled "far" and still be understood.

This is IMHO out of the scope of re, and perhaps case-insensitivity
should have been too.  Perhaps it /would/ have been, if regular
expressions hadn't come from the ASCII world where these things are
easy.

/Jorgen

-- 
  // Jorgen Grahn <grahn@  Oo  o.   .     .
\X/     snipabacken.se>   O  o   .


From robsuttonjr at yahoo.com  Fri May 17 14:36:07 2013
From: robsuttonjr at yahoo.com (Rob Sutton)
Date: Fri, 17 May 2013 11:36:07 -0700 (PDT)
Subject: Back-end Python Developer Seeking Telecommute Work
Message-ID: <200802d6-2edc-4628-b1f3-8633cd013c50@googlegroups.com>

I am seeking part/full time work as a back-end Python developer (telecommute or Utah only).  I have been maintaining a Debian/Python/Django/Apache/PostgreSQL/PHP/MySql web application for 3 years on my own.  I do all the development, database and system management myself. I can setup a complete system from scratch remotely or setup the hosting service.  I have experience with Virtualbox and ProxMox virtualization.  I have expereince in all areas of IT including telecom, programming, networking, hardware and software.  Worked with Retail stores, warehousing systems, accounting software, data interchange, hardware interfacing, etc.  

Regards,

Rob


From dihedral88888 at googlemail.com  Fri May 17 15:00:23 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Fri, 17 May 2013 12:00:23 -0700 (PDT)
Subject: Back-end Python Developer Seeking Telecommute Work
In-Reply-To: <200802d6-2edc-4628-b1f3-8633cd013c50@googlegroups.com>
References: <200802d6-2edc-4628-b1f3-8633cd013c50@googlegroups.com>
Message-ID: <9bd559a3-8ea1-43fa-ae12-6fbe64b515a8@googlegroups.com>

Rob Sutton? 2013?5?18????UTC+8??2?36?07????
> I am seeking part/full time work as a back-end Python developer (telecommute or Utah only).  I have been maintaining a Debian/Python/Django/Apache/PostgreSQL/PHP/MySql web application for 3 years on my own.  I do all the development, database and system management myself. I can setup a complete system from scratch remotely or setup the hosting service.  I have experience with Virtualbox and ProxMox virtualization.  I have expereince in all areas of IT including telecom, programming, networking, hardware and software.  Worked with Retail stores, warehousing systems, accounting software, data interchange, hardware interfacing, etc.  
> 
> 
> 
> Regards,
> 
> 
> 
> Rob

Nic,e I am working on several similar projects including 
EDA automations with expert systems and some VLSI-FPGA IP cores.

Anyway I have to get some US patents first.



From nawkboy+python at gmail.com  Fri May 17 15:25:10 2013
From: nawkboy+python at gmail.com (James Carpenter)
Date: Fri, 17 May 2013 14:25:10 -0500
Subject: Continuous Deployment Style Build System for Python
Message-ID: <CAAndj4s18LRcTaypD9zDgRtEtrH8w1421dvanrJ0WEBH+hjHBQ@mail.gmail.com>

Defend Against Fruit is focused on providing a pragmatic,
continuous deployment style build system for Python.
Current Python build systems do not properly account for
the needs of effective continuous deployment. This package
extends the Python tooling to add the missing pieces,
including integration with Artifactory.

With an eye to agile development principles and fast-feedback,
we want a build system which satisfies the following goals:

* Every SCM change-set committed should result in a
  potentially shippable release candidate.

* When a defect is introduced, we want to immediately detect
  and isolate the offending SCM change-set. This is true
  even if the defect was introduced into a library we depend upon.

* Library management should be so easy as to never impede code changes,
  even in multi-component architecture.

More details available at: http://teamfruit.github.io/defend_against_fruit/

License: Apache Public License v2

Authors:

James Carpenter
jcarpenter621 at yahoo.com
LinkedIn: http://www.linkedin.com/in/jamescarpenter1

Matthew Tardiff
mattrix at gmail.com
LinkedIn: http://www.linkedin.com/in/matthewtardiff
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From bradley.wright.biz at gmail.com  Sat May 18 00:19:54 2013
From: bradley.wright.biz at gmail.com (Bradley Wright)
Date: Fri, 17 May 2013 21:19:54 -0700 (PDT)
Subject: Two Dictionaries and a Sum!
Message-ID: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>

Confusing subject for a confusing problem (to a novice like me of course!)
Thx for the help in advance folks

I have (2) dictionaries:

prices = {
    "banana": 4,
    "apple": 2,
    "orange": 1.5,
    "pear": 3
}
    
stock = {
    "banana": 6,
    "apple": 0,
    "orange": 32,
    "pear": 15
}

Here's my instructions:

consider this as an inventory and calculate the sum (thats 4*6 = 24 bananas!)

HERES MY CODE:

for key in prices:
    print prices[key]*stock[key]

HERES THE OUTPUT:

48.0
45
24
0

ISSUE:
I need to find a way to add all of those together...any pointers?


From fjctlzy at gmail.com  Sat May 18 00:30:45 2013
From: fjctlzy at gmail.com (Spacelee)
Date: Sat, 18 May 2013 12:30:45 +0800
Subject: Two Dictionaries and a Sum!
In-Reply-To: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>
References: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>
Message-ID: <CAH+LXce8GObQf7LeRt4kCvCpU8kceYu94_px46BkccRjay45NA@mail.gmail.com>

for key in prices.keys():
    print prices[key]*stock[key]


On Sat, May 18, 2013 at 12:19 PM, Bradley Wright <
bradley.wright.biz at gmail.com> wrote:

> Confusing subject for a confusing problem (to a novice like me of course!)
> Thx for the help in advance folks
>
> I have (2) dictionaries:
>
> prices = {
>     "banana": 4,
>     "apple": 2,
>     "orange": 1.5,
>     "pear": 3
> }
>
> stock = {
>     "banana": 6,
>     "apple": 0,
>     "orange": 32,
>     "pear": 15
> }
>
> Here's my instructions:
>
> consider this as an inventory and calculate the sum (thats 4*6 = 24
> bananas!)
>
> HERES MY CODE:
>
> for key in prices:
>     print prices[key]*stock[key]
>
> HERES THE OUTPUT:
>
> 48.0
> 45
> 24
> 0
>
> ISSUE:
> I need to find a way to add all of those together...any pointers?
> --
> http://mail.python.org/mailman/listinfo/python-list
>



-- 
*Space Lee*
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From rosuav at gmail.com  Sat May 18 01:10:30 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 18 May 2013 15:10:30 +1000
Subject: Two Dictionaries and a Sum!
In-Reply-To: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>
References: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>
Message-ID: <CAPTjJmq+UGR_WgZx+OCEf=DGKc57k0+efNUqTBDarPz3hy8i+w@mail.gmail.com>

On Sat, May 18, 2013 at 2:19 PM, Bradley Wright
<bradley.wright.biz at gmail.com> wrote:
> Confusing subject for a confusing problem (to a novice like me of course!)
> Thx for the help in advance folks
>
> I have (2) dictionaries:
>
> prices = {
>     "banana": 4,
>     "apple": 2,
>     "orange": 1.5,
>     "pear": 3
> }
>
> stock = {
>     "banana": 6,
>     "apple": 0,
>     "orange": 32,
>     "pear": 15
> }
>
> Here's my instructions:
>
> consider this as an inventory and calculate the sum (thats 4*6 = 24 bananas!)

Let me reword your problem a little, maybe it'll be a bit clearer.
You're trying to calculate the total value of all stock on hand, eg
for insurance purposes. That's not 24 bananas, that's $24 of bananas.
And the part you want now is to get the total value of your entire
stock. Great! You're very close to there...

> HERES MY CODE:
>
> for key in prices:
>     print prices[key]*stock[key]
>
> ISSUE:
> I need to find a way to add all of those together...any pointers?

... you just need to accumulate a sum. Since this is almost certainly
homework, I won't give you the answer, but here are a few pointers:

* You'll need a single variable (I use the term sloppily, Python
doesn't actually have variables per se) which will collect the final
total.
* Inside your loop, you're currently printing out an int/float with
the value of the current item. Just add it onto your accumulator.
* Python will happily work with integers and floats together, so you
can just do what's obvious and it'll work.

See where that takes you. Have fun! :)

ChrisA


From hektorlg at gmail.com  Sat May 18 01:20:25 2013
From: hektorlg at gmail.com (nanobio)
Date: Fri, 17 May 2013 22:20:25 -0700 (PDT)
Subject: Two Dictionaries and a Sum!
In-Reply-To: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>
References: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>
Message-ID: <38fdb42f-b233-4da5-8936-7439072edfbd@googlegroups.com>

total,amount=0,0
for key in prices.keys():
   price=prices[key]*stock[key]
   total+=price
   print "%s %s" % (price,total)


From hektorlg at gmail.com  Sat May 18 01:22:45 2013
From: hektorlg at gmail.com (nanobio)
Date: Fri, 17 May 2013 22:22:45 -0700 (PDT)
Subject: Two Dictionaries and a Sum!
In-Reply-To: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>
References: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>
Message-ID: <c954581b-fa06-41ab-8d02-833269369cc5@googlegroups.com>

total,amount=0,0
for key in prices.keys():
    amount=prices[key]*stock[key]
    total+=amount
    print "%s %s" % (amount,total)


From roy at panix.com  Sat May 18 09:22:47 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 18 May 2013 09:22:47 -0400
Subject: Two Dictionaries and a Sum!
References: <6012d69f-b65e-4d65-90c4-f04876853f5e@googlegroups.com>
Message-ID: <roy-9D8691.09224718052013@news.panix.com>

In article <6012d69f-b65e-4d65-90c4-f04876853f5e at googlegroups.com>,
 Bradley Wright <bradley.wright.biz at gmail.com> wrote:

> Confusing subject for a confusing problem (to a novice like me of course!)
> Thx for the help in advance folks
> 
> I have (2) dictionaries:
> 
> prices = {
>     "banana": 4,
>     "apple": 2,
>     "orange": 1.5,
>     "pear": 3
> }
>     
> stock = {
>     "banana": 6,
>     "apple": 0,
>     "orange": 32,
>     "pear": 15
> }
> 
> Here's my instructions:

Hmmm, homework for a class?

> consider this as an inventory and calculate the sum (thats 4*6 = 24 bananas!)

I suspect what you're trying to say is that bananas cost BTC 4 each, and 
since you've got 6 bananas, you've got BTC 24 worth of bananas, yes?  
And now you want to find the total value of your fruit supply?

>> HERES MY CODE:
> 
> for key in prices:
>     print prices[key]*stock[key]
> 
> HERES THE OUTPUT:
> 
> 48.0
> 45
> 24
> 0

So far, so good.  A couple of things you may have noticed along the way:

1) Your orange unit price was a float, so the total value of all your 
oranges is a float as well.  That's how math works in Python.

2) The keys are presented in random order.  To make the output easier to 
interpret, you might want to do:

    print key, prices[key]*stock[key]


> ISSUE:
> I need to find a way to add all of those together...any pointers?

The most straight-forward way would be something like:

total = 0
for key in prices:
    fruit_subtotal = prices[key]*stock[key]
    total += fruit_subtotal
    print key, fruit_subtotal

print total


There are better ways to do this in Python, but start like this and get 
that to work.


From avnesh.nitk at gmail.com  Sat May 18 00:48:54 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Fri, 17 May 2013 21:48:54 -0700 (PDT)
Subject: how to run another file inside current file?
Message-ID: <67c4dd92-7e6a-4955-850b-0c21c2708e05@googlegroups.com>

hi,
   I want to run a another file inside a ached.add_cron_job(..). how is it possible, please help me, I have a file otherFile.py for execution inside current file.
I know it is very easy question but i m unable to get anything, please help me.
example --

import otherFile
from apscheduler.scheduler import Scheduler
sched = Scheduler()
sched.start()

def job_function():
    # Can I here add that file for execution, Or can i add that file directly inside cron?
   
sched.add_cron_job(job_function, month='1-12', day='1-31', hour='0-23',minute='44-49')


From fjctlzy at gmail.com  Sat May 18 06:32:54 2013
From: fjctlzy at gmail.com (fjctlzy at gmail.com)
Date: Sat, 18 May 2013 18:32:54 +0800
Subject: how to run another file inside current file?
Message-ID: <ruvcdl66s9y1yx5t37qa6cuj.1368873174657@email.android.com>

subprocess?



????????

Avnesh Shakya <avnesh.nitk at gmail.com>???

>hi,
>   I want to run a another file inside a ached.add_cron_job(..). how is it possible, please help me, I have a file otherFile.py for execution inside current file.
>I know it is very easy question but i m unable to get anything, please help me.
>example --
>
>import otherFile
>from apscheduler.scheduler import Scheduler
>sched = Scheduler()
>sched.start()
>
>def job_function():
>    # Can I here add that file for execution, Or can i add that file directly inside cron?
>   
>sched.add_cron_job(job_function, month='1-12', day='1-31', hour='0-23',minute='44-49')
>-- 
>http://mail.python.org/mailman/listinfo/python-list

From kevin.xgr at gmail.com  Sat May 18 07:15:14 2013
From: kevin.xgr at gmail.com (Kevin Xi)
Date: Sat, 18 May 2013 19:15:14 +0800
Subject: how to run another file inside current file?
In-Reply-To: <67c4dd92-7e6a-4955-850b-0c21c2708e05@googlegroups.com>
References: <67c4dd92-7e6a-4955-850b-0c21c2708e05@googlegroups.com>
Message-ID: <CAG=aD5aMmunaqXzdP9eUiTg6uQvBjny0xxAbXMD5DCP9-zTocg@mail.gmail.com>

Hi,
It's better to specify version of python you work with. I know nothing
about python 3 but in python 2 you can do this with `exec`. Example:

> f = file('otherFile.py')
> exec f

For more, read the doc:
http://docs.python.org/2.7/reference/simple_stmts.html#the-exec-statement
HTH


                                                   Kevin

2013/5/18 Avnesh Shakya <avnesh.nitk at gmail.com>

> hi,
>    I want to run a another file inside a ached.add_cron_job(..). how is it
> possible, please help me, I have a file otherFile.py for execution inside
> current file.
> I know it is very easy question but i m unable to get anything, please
> help me.
> example --
>
> import otherFile
> from apscheduler.scheduler import Scheduler
> sched = Scheduler()
> sched.start()
>
> def job_function():
>     # Can I here add that file for execution, Or can i add that file
> directly inside cron?
>
> sched.add_cron_job(job_function, month='1-12', day='1-31',
> hour='0-23',minute='44-49')
> --
> http://mail.python.org/mailman/listinfo/python-list
>



-- 
????????????????
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From tjreedy at udel.edu  Sat May 18 12:39:16 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sat, 18 May 2013 12:39:16 -0400
Subject: how to run another file inside current file?
In-Reply-To: <CAG=aD5aMmunaqXzdP9eUiTg6uQvBjny0xxAbXMD5DCP9-zTocg@mail.gmail.com>
References: <67c4dd92-7e6a-4955-850b-0c21c2708e05@googlegroups.com>
	<CAG=aD5aMmunaqXzdP9eUiTg6uQvBjny0xxAbXMD5DCP9-zTocg@mail.gmail.com>
Message-ID: <kn8arb$vgc$1@ger.gmane.org>

On 5/18/2013 7:15 AM, Kevin Xi wrote:
> Hi,
> It's better to specify version of python you work with.

Absolutely.


  I know nothing
> about python 3 but in python 2 you can do this with `exec`. Example:
>
>  > f = file('otherFile.py')
>  > exec f

Py 2 has execfile that does the above. Py 3 do as above except that exec 
is a function.

with open('otherfile.py') as f:
   exex(f)


> For more, read the doc:
> http://docs.python.org/2.7/reference/simple_stmts.html#the-exec-statement
> HTH






From debruinjj at gmail.com  Sat May 18 04:58:13 2013
From: debruinjj at gmail.com (Jurgens de Bruin)
Date: Sat, 18 May 2013 01:58:13 -0700 (PDT)
Subject: Please help with Threading
Message-ID: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>

This is my first script where I want to use the python threading module. I have a large dataset which is a list of dict this can be as much as 200 dictionaries in the list. The final goal is a  histogram for each dict 16 histograms on a page ( 4x4 ) - this already works. 
What I currently do is a create a nested list [ [ {}  ], [ {} ] ] each inner list contains 16 dictionaries, thus each inner list is a single page of 16 histograms. Iterating over the outer-list  and creating the graphs takes to long. So I would like multiple inner-list to be processes simultaneously and creating the graphs in "parallel". 
I am trying to use the python threading for this. I create 4 threads loop over the outer-list and send a inner-list to the thread. This seems to work if my nested lists only contains 2 elements - thus less elements than threads. Currently the scripts runs and then seems to get hung up. I monitor the resource  on my mac and python starts off good using 80% and when the 4-thread is created the CPU usages drops to 0%. 

My thread creating is based on the following : http://www.tutorialspoint.com/python/python_multithreading.htm

Any help would be create!!!


From __peter__ at web.de  Sat May 18 05:09:03 2013
From: __peter__ at web.de (Peter Otten)
Date: Sat, 18 May 2013 11:09:03 +0200
Subject: Please help with Threading
References: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>
Message-ID: <kn7gfa$kl7$1@ger.gmane.org>

Jurgens de Bruin wrote:

> This is my first script where I want to use the python threading module. I
> have a large dataset which is a list of dict this can be as much as 200
> dictionaries in the list. The final goal is a  histogram for each dict 16
> histograms on a page ( 4x4 ) - this already works.
> What I currently do is a create a nested list [ [ {}  ], [ {} ] ] each
> inner list contains 16 dictionaries, thus each inner list is a single page
> of 16 histograms. Iterating over the outer-list  and creating the graphs
> takes to long. So I would like multiple inner-list to be processes
> simultaneously and creating the graphs in "parallel".
> I am trying to use the python threading for this. I create 4 threads loop
> over the outer-list and send a inner-list to the thread. This seems to
> work if my nested lists only contains 2 elements - thus less elements than
> threads. Currently the scripts runs and then seems to get hung up. I
> monitor the resource  on my mac and python starts off good using 80% and
> when the 4-thread is created the CPU usages drops to 0%.
> 
> My thread creating is based on the following :
> http://www.tutorialspoint.com/python/python_multithreading.htm
> 
> Any help would be create!!!

Can you show us the code?



From debruinjj at gmail.com  Sat May 18 07:23:12 2013
From: debruinjj at gmail.com (Jurgens de Bruin)
Date: Sat, 18 May 2013 04:23:12 -0700 (PDT)
Subject: Please help with Threading
In-Reply-To: <mailman.1796.1368868155.3114.python-list@python.org>
References: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>
	<mailman.1796.1368868155.3114.python-list@python.org>
Message-ID: <fb116be9-e14a-4a17-950a-010e3b98a4c2@googlegroups.com>

I will post code - the entire scripts is 1000 lines of code - can I post the threading functions only?


From __peter__ at web.de  Sat May 18 08:01:04 2013
From: __peter__ at web.de (Peter Otten)
Date: Sat, 18 May 2013 14:01:04 +0200
Subject: Please help with Threading
References: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>
	<mailman.1796.1368868155.3114.python-list@python.org>
	<fb116be9-e14a-4a17-950a-010e3b98a4c2@googlegroups.com>
Message-ID: <kn7qhr$b9l$1@ger.gmane.org>

Jurgens de Bruin wrote:

> I will post code - the entire scripts is 1000 lines of code - can I post
> the threading functions only?

Try to condense it to the relevant parts, but make sure that it can be run 
by us.

As a general note, when you add new stuff to an existing longish script it 
is always a good idea to write it in such a way that you can test it 
standalone so that you can have some confidence that it will work as 
designed once you integrate it with your old code.



From davea at davea.name  Sat May 18 09:55:56 2013
From: davea at davea.name (Dave Angel)
Date: Sat, 18 May 2013 09:55:56 -0400
Subject: Please help with Threading
In-Reply-To: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>
References: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>
Message-ID: <5197886C.2020109@davea.name>

On 05/18/2013 04:58 AM, Jurgens de Bruin wrote:
> This is my first script where I want to use the python threading module. I have a large dataset which is a list of dict this can be as much as 200 dictionaries in the list. The final goal is a  histogram for each dict 16 histograms on a page ( 4x4 ) - this already works.
> What I currently do is a create a nested list [ [ {}  ], [ {} ] ] each inner list contains 16 dictionaries, thus each inner list is a single page of 16 histograms. Iterating over the outer-list  and creating the graphs takes to long. So I would like multiple inner-list to be processes simultaneously and creating the graphs in "parallel".
> I am trying to use the python threading for this. I create 4 threads loop over the outer-list and send a inner-list to the thread. This seems to work if my nested lists only contains 2 elements - thus less elements than threads. Currently the scripts runs and then seems to get hung up. I monitor the resource  on my mac and python starts off good using 80% and when the 4-thread is created the CPU usages drops to 0%.
>
> My thread creating is based on the following : http://www.tutorialspoint.com/python/python_multithreading.htm
>
> Any help would be create!!!
>

CPython, and apparently (all of?) the other current Python 
implementations, uses a GIL to prevent multi-threaded applications from 
shooting themselves in the foot.

However the practical effect of the GIL is that CPU-bound applications 
do not multi-thread efficiently;  the single-threaded version usually 
runs faster.

The place where CPython programs gain from multithreading is where each 
thread spends much of its time waiting for some external trigger.

(More specifically, if such a wait is inside well-written C code, it 
releases the GIL so other threads can get useful work done.  Example is 
a thread waiting for internet activity, and blocks inside a system call)


-- 
DaveA


From carlosnepomuceno at outlook.com  Sat May 18 20:02:29 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 19 May 2013 03:02:29 +0300
Subject: Please help with Threading
In-Reply-To: <13lfp8lds6e2e41rtsnvqimcb6inu7p28o@invalid.netcom.com>
References: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>,
	<13lfp8lds6e2e41rtsnvqimcb6inu7p28o@invalid.netcom.com>
Message-ID: <BLU176-W444B989132C26C3A305CB7D7AE0@phx.gbl>

----------------------------------------
> To: python-list at python.org
> From: wlfraed at ix.netcom.com
> Subject: Re: Please help with Threading
> Date: Sat, 18 May 2013 15:28:56 -0400
>
> On Sat, 18 May 2013 01:58:13 -0700 (PDT), Jurgens de Bruin
> <debruinjj at gmail.com> declaimed the following in
> gmane.comp.python.general:
>
>> This is my first script where I want to use the python threading module. I have a large dataset which is a list of dict this can be as much as 200 dictionaries in the list. The final goal is a histogram for each dict 16 histograms on a page ( 4x4 ) - this already works.
>> What I currently do is a create a nested list [ [ {} ], [ {} ] ] each inner list contains 16 dictionaries, thus each inner list is a single page of 16 histograms. Iterating over the outer-list and creating the graphs takes to long. So I would like multiple inner-list to be processes simultaneously and creating the graphs in "parallel".
>> I am trying to use the python threading for this. I create 4 threads loop over the outer-list and send a inner-list to the thread. This seems to work if my nested lists only contains 2 elements - thus less elements than threads. Currently the scripts runs and then seems to get hung up. I monitor the resource on my mac and python starts off good using 80% and when the 4-thread is created the CPU usages drops to 0%.
>>
>
> The odds are good that this is just going to run slower...

Just been told that GIL doesn't make things slower, but as I didn't know that such a thing even existed I went out looking for more info and found that document: http://www.dabeaz.com/python/UnderstandingGIL.pdf

Is it current? I didn't know Python threads aren't preemptive. Seems to be something really old considering the state of the art on parallel execution on multi-cores.

What's the catch on making Python threads preemptive? Are there any ongoing projects to make that?

> One: The common Python implementation uses a global interpreter lock
> to prevent interpreted code from interfering with itself in multiple
> threads. So "number cruncher" applications don't gain any speed from
> being partitioned into thread -- even on a multicore processor, only one
> thread can have the GIL at a time. On top of that, you have the overhead
> of the interpreter switching between threads (GIL release on one thread,
> GIL acquire for the next thread).
>
> Python threads work fine if the threads either rely on intelligent
> DLLs for number crunching (instead of doing nested Python loops to
> process a numeric array you pass it to something like NumPy which
> releases the GIL while crunching a copy of the array) or they do lots of
> I/O and have to wait for I/O devices (while one thread is waiting for
> the write/read operation to complete, another thread can do some number
> crunching).
>
> If you really need to do this type of number crunching in Python
> level code, you'll want to look into the multiprocessing library
> instead. That will create actual OS processes (each with a copy of the
> interpreter, and not sharing memory) and each of those can run on a core
> without conflicting on the GIL.

Which library do you suggest?

> --
> Wulfraed Dennis Lee Bieber AF6VN
> wlfraed at ix.netcom.com HTTP://wlfraed.home.netcom.com/
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rosuav at gmail.com  Sat May 18 20:38:14 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 19 May 2013 10:38:14 +1000
Subject: Please help with Threading
In-Reply-To: <BLU176-W444B989132C26C3A305CB7D7AE0@phx.gbl>
References: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>
	<13lfp8lds6e2e41rtsnvqimcb6inu7p28o@invalid.netcom.com>
	<BLU176-W444B989132C26C3A305CB7D7AE0@phx.gbl>
Message-ID: <CAPTjJmoJExzBAg7LXodAJVLCe=dpUqOqeUjzXLCWWzxbqz=vEQ@mail.gmail.com>

On Sun, May 19, 2013 at 10:02 AM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> I didn't know Python threads aren't preemptive. Seems to be something really old considering the state of the art on parallel execution on multi-cores.
>
> What's the catch on making Python threads preemptive? Are there any ongoing projects to make that?

Preemption isn't really the issue here. On the C level, preemptive vs
cooperative usually means the difference between a stalled thread
locking everyone else out and not doing so. Preemption is done at a
lower level than user code (eg the operating system or the CPU),
meaning that user code can't retain control of the CPU.

With interpreted code eg in CPython, it's easy to implement preemption
in the interpreter. I don't know how it's actually done, but one easy
implementation would be "every N bytecode instructions, context
switch". It's still done at a lower level than user code (N bytecode
instructions might all actually be a single tight loop that the
programmer didn't realize was infinite), but it's not at the OS level.

But none of that has anything to do with multiple core usage. The
problem there is that shared data structures need to be accessed
simultaneously, and in CPython, there's a Global Interpreter Lock to
simplify that; but the consequence of the GIL is that no two threads
can simultaneously execute user-level code. There have been
GIL-removal proposals at various times, but the fact remains that a
global lock makes a huge amount of sense and gives pretty good
performance across the board. There's always multiprocessing when you
need multiple CPU-bound threads; it's an explicit way to separate the
shared data (what gets transferred) from local (what doesn't).

ChrisA


From rosuav at gmail.com  Sun May 19 17:52:23 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 20 May 2013 07:52:23 +1000
Subject: Please help with Threading
In-Reply-To: <mghip81l8gs30fjvkdfdp5h9fn622habdg@invalid.netcom.com>
References: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>
	<13lfp8lds6e2e41rtsnvqimcb6inu7p28o@invalid.netcom.com>
	<BLU176-W444B989132C26C3A305CB7D7AE0@phx.gbl>
	<CAPTjJmoJExzBAg7LXodAJVLCe=dpUqOqeUjzXLCWWzxbqz=vEQ@mail.gmail.com>
	<mghip81l8gs30fjvkdfdp5h9fn622habdg@invalid.netcom.com>
Message-ID: <CAPTjJmpYQxST3Y-Rz+mR2eU1=AHFj35snYJ877nqfweOQKABbQ@mail.gmail.com>

On Mon, May 20, 2013 at 7:46 AM, Dennis Lee Bieber
<wlfraed at ix.netcom.com> wrote:
> On Sun, 19 May 2013 10:38:14 +1000, Chris Angelico <rosuav at gmail.com>
> declaimed the following in gmane.comp.python.general:
>> With interpreted code eg in CPython, it's easy to implement preemption
>> in the interpreter. I don't know how it's actually done, but one easy
>> implementation would be "every N bytecode instructions, context
>> switch". It's still done at a lower level than user code (N bytecode
>
>         Which IS how the common Python interpreter does it -- barring the
> thread making some system call that triggers a preemption ahead of time
> (even time.sleep(0.0) triggers scheduling). Forget if the default is 20
> or 100 byte-code instructions -- as I recall, it DID change a few
> versions back.

Incidentally, is the context-switch check the same as the check for
interrupt signal raising KeyboardInterrupt? ISTR that was another
"every N instructions" check.

ChrisA


From davea at davea.name  Sun May 19 21:04:42 2013
From: davea at davea.name (Dave Angel)
Date: Sun, 19 May 2013 21:04:42 -0400
Subject: Please help with Threading
In-Reply-To: <mghip81l8gs30fjvkdfdp5h9fn622habdg@invalid.netcom.com>
References: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>
	<13lfp8lds6e2e41rtsnvqimcb6inu7p28o@invalid.netcom.com>
	<BLU176-W444B989132C26C3A305CB7D7AE0@phx.gbl>
	<CAPTjJmoJExzBAg7LXodAJVLCe=dpUqOqeUjzXLCWWzxbqz=vEQ@mail.gmail.com>
	<mghip81l8gs30fjvkdfdp5h9fn622habdg@invalid.netcom.com>
Message-ID: <519976AA.3040201@davea.name>

On 05/19/2013 05:46 PM, Dennis Lee Bieber wrote:
> On Sun, 19 May 2013 10:38:14 +1000, Chris Angelico <rosuav at gmail.com>
> declaimed the following in gmane.comp.python.general:
>
>> On Sun, May 19, 2013 at 10:02 AM, Carlos Nepomuceno
>> <carlosnepomuceno at outlook.com> wrote:
>>> I didn't know Python threads aren't preemptive. Seems to be something really old considering the state of the art on parallel execution on multi-cores.
>>>
>>> What's the catch on making Python threads preemptive? Are there any ongoing projects to make that?
>>
> 	<snip>
>
>> With interpreted code eg in CPython, it's easy to implement preemption
>> in the interpreter. I don't know how it's actually done, but one easy
>> implementation would be "every N bytecode instructions, context
>> switch". It's still done at a lower level than user code (N bytecode
>
> 	Which IS how the common Python interpreter does it -- barring the
> thread making some system call that triggers a preemption ahead of time
> (even time.sleep(0.0) triggers scheduling). Forget if the default is 20
> or 100 byte-code instructions -- as I recall, it DID change a few
> versions back.
>
> 	Part of the context switch is to transfer the GIL from the preempted
> thread to the new thread.
>
> 	So, overall, on a SINGLE CORE processor running multiple CPU bound
> threads takes a bit longer just due to the overhead of thread swapping.
>
> 	On a multi-core processor, the effect is the same, since -- even
> though one may have a thread running on each core -- the GIL is only
> assigned to one thread, and other threads get blocked when trying to
> access runtime data structures. And you may have even more overhead from
> processor cache misses if the a thread gets assigned to a different
> core.
>
> 	(yes -- I'm restating the same thing as I had just trimmed below
> this point... but the target is really the OP, where repetition may be
> helpful in understanding)
>

So what's the mapping between real (OS) threads, and the fake ones 
Python uses?  The OS keeps track of a separate stack and context for 
each thread it knows about;  are they one-to-one with the ones you're 
describing here?  If so, then any OS thread that gets scheduled will 
almost always find it can't get the GIL, and spend time thrashing.   But 
the change that CPython does intentionally would be equivalent to a 
sleep(0).

On the other hand, if these threads are distinct from the OS threads, is 
it done with some sort of thread pool, where CPython has its own stack, 
and doesn't really use the one managed by the OS?

Understand the only OS threading I really understand is the one in 
Windows (which I no longer use).  So assuming Linux has some form of 
lightweight threading, the distinction above may not map very well.



-- 
DaveA


From cs at zip.com.au  Sat May 18 23:10:36 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Sun, 19 May 2013 13:10:36 +1000
Subject: Please help with Threading
In-Reply-To: <BLU176-W444B989132C26C3A305CB7D7AE0@phx.gbl>
References: <BLU176-W444B989132C26C3A305CB7D7AE0@phx.gbl>
Message-ID: <20130519031036.GA24155@cskk.homeip.net>

On 19May2013 03:02, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
| Just been told that GIL doesn't make things slower, but as I
| didn't know that such a thing even existed I went out looking for
| more info and found that document:
| http://www.dabeaz.com/python/UnderstandingGIL.pdf
| 
| Is it current? I didn't know Python threads aren't preemptive.
| Seems to be something really old considering the state of the art
| on parallel execution on multi-cores.
| What's the catch on making Python threads preemptive? Are there any ongoing projects to make that?

Depends what you mean by preemptive. If you have multiple CPU bound
pure Python threads they will all get CPU time without any of them
explicitly yeilding control. But thread switching happens between
python instructions, mediated by the interpreter.

The standard answers for using multiple cores is to either run
multiple processes (either explicitly spawning other executables,
or spawning child python processes using the multiprocessing module),
or to use (as suggested) libraries that can do the compute intensive
bits themselves, releasing the while doing so so that the Python
interpreter can run other bits of your python code.

Plenty of OS system calls (and calls to other libraries from the
interpreter) release the GIL during the call. Other python threads
can run during that window.

And there are other Python implementations other than CPython.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Processes are like potatoes.    - NCR device driver manual


From carlosnepomuceno at outlook.com  Mon May 20 03:45:22 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 20 May 2013 10:45:22 +0300
Subject: Please help with Threading
In-Reply-To: <20130519031036.GA24155@cskk.homeip.net>
References: <BLU176-W444B989132C26C3A305CB7D7AE0@phx.gbl>,
	<20130519031036.GA24155@cskk.homeip.net>
Message-ID: <BLU176-W30835C05EC370E316998E1D7AF0@phx.gbl>

----------------------------------------
> Date: Sun, 19 May 2013 13:10:36 +1000
> From: cs at zip.com.au
> To: carlosnepomuceno at outlook.com
> CC: python-list at python.org
> Subject: Re: Please help with Threading
>
> On 19May2013 03:02, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> | Just been told that GIL doesn't make things slower, but as I
> | didn't know that such a thing even existed I went out looking for
> | more info and found that document:
> | http://www.dabeaz.com/python/UnderstandingGIL.pdf
> |
> | Is it current? I didn't know Python threads aren't preemptive.
> | Seems to be something really old considering the state of the art
> | on parallel execution on multi-cores.
> | What's the catch on making Python threads preemptive? Are there any ongoing projects to make that?
>
> Depends what you mean by preemptive. If you have multiple CPU bound
> pure Python threads they will all get CPU time without any of them
> explicitly yeilding control. But thread switching happens between
> python instructions, mediated by the interpreter.

I meant operating system preemptive. I've just checked and Python does not start Windows threads.

> The standard answers for using multiple cores is to either run
> multiple processes (either explicitly spawning other executables,
> or spawning child python processes using the multiprocessing module),
> or to use (as suggested) libraries that can do the compute intensive
> bits themselves, releasing the while doing so so that the Python
> interpreter can run other bits of your python code.

I've just discovered the multiprocessing module[1] and will make some tests with it later. Are there any other modules for that purpose?

I've found the following articles about Python threads. Any suggestions?

http://www.ibm.com/developerworks/aix/library/au-threadingpython/
http://pymotw.com/2/threading/index.html
http://www.laurentluce.com/posts/python-threads-synchronization-locks-rlocks-semaphores-conditions-events-and-queues/


[1] http://docs.python.org/2/library/multiprocessing.html


> Plenty of OS system calls (and calls to other libraries from the
> interpreter) release the GIL during the call. Other python threads
> can run during that window.
>
> And there are other Python implementations other than CPython.
>
> Cheers,
> --
> Cameron Simpson <cs at zip.com.au>
>
> Processes are like potatoes. - NCR device driver manual 		 	   		  

From fabiosantosart at gmail.com  Mon May 20 02:25:17 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 20 May 2013 07:25:17 +0100
Subject: Please help with Threading
In-Reply-To: <13lfp8lds6e2e41rtsnvqimcb6inu7p28o@invalid.netcom.com>
References: <7baacf5a-0c50-4935-ad5b-148c208d759b@googlegroups.com>
	<13lfp8lds6e2e41rtsnvqimcb6inu7p28o@invalid.netcom.com>
Message-ID: <CAA=1kxR4GD1xLBPJK9sKb_LrVbi-UScBxRbx2vacM989K+YV2Q@mail.gmail.com>

On 18 May 2013 20:33, "Dennis Lee Bieber" <wlfraed at ix.netcom.com> wrote:
>         Python threads work fine if the threads either rely on intelligent
> DLLs for number crunching (instead of doing nested Python loops to
> process a numeric array you pass it to something like NumPy which
> releases the GIL while crunching a copy of the array) or they do lots of
> I/O and have to wait for I/O devices (while one thread is waiting for
> the write/read operation to complete, another thread can do some number
> crunching).

Has nobody thought of a context manager to allow a part of your code to
free up the GIL? I think the GIL is not inherently bad, but if it poses a
problem at times, there should be a way to get it out of your... Way.
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From cs at zip.com.au  Mon May 20 03:45:14 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 20 May 2013 17:45:14 +1000
Subject: Please help with Threading
In-Reply-To: <CAA=1kxR4GD1xLBPJK9sKb_LrVbi-UScBxRbx2vacM989K+YV2Q@mail.gmail.com>
References: <CAA=1kxR4GD1xLBPJK9sKb_LrVbi-UScBxRbx2vacM989K+YV2Q@mail.gmail.com>
Message-ID: <20130520074514.GA33353@cskk.homeip.net>

On 20May2013 07:25, F?bio Santos <fabiosantosart at gmail.com> wrote:
| On 18 May 2013 20:33, "Dennis Lee Bieber" <wlfraed at ix.netcom.com> wrote:
| >         Python threads work fine if the threads either rely on intelligent
| > DLLs for number crunching (instead of doing nested Python loops to
| > process a numeric array you pass it to something like NumPy which
| > releases the GIL while crunching a copy of the array) or they do lots of
| > I/O and have to wait for I/O devices (while one thread is waiting for
| > the write/read operation to complete, another thread can do some number
| > crunching).
| 
| Has nobody thought of a context manager to allow a part of your code to
| free up the GIL? I think the GIL is not inherently bad, but if it poses a
| problem at times, there should be a way to get it out of your... Way.

The GIL makes individual python operations thread safe by never
running two at once. This makes the implementation of the operations
simpler, faster and safer. It is probably totally infeasible to
write meaningful python code inside your suggested context
manager that didn't rely on the GIL; if the GIL were not held the
code would be unsafe.

It is easy for a C extension to release the GIL, and then to do
meaningful work until it needs to return to python land. Most C
extensions will do that around non-trivial sections, and anything
that may stall in the OS.

So your use case for the context manager doesn't fit well.
-- 
Cameron Simpson <cs at zip.com.au>

Gentle suggestions being those which are written on rocks of less than 5lbs.
        - Tracy Nelson in comp.lang.c


From carlosnepomuceno at outlook.com  Mon May 20 03:53:24 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 20 May 2013 10:53:24 +0300
Subject: Please help with Threading
In-Reply-To: <20130520074514.GA33353@cskk.homeip.net>
References: <CAA=1kxR4GD1xLBPJK9sKb_LrVbi-UScBxRbx2vacM989K+YV2Q@mail.gmail.com>,
	<20130520074514.GA33353@cskk.homeip.net>
Message-ID: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>

----------------------------------------
> Date: Mon, 20 May 2013 17:45:14 +1000
> From: cs at zip.com.au
> To: fabiosantosart at gmail.com
> Subject: Re: Please help with Threading
> CC: python-list at python.org; wlfraed at ix.netcom.com
>
> On 20May2013 07:25, F?bio Santos <fabiosantosart at gmail.com> wrote:
> | On 18 May 2013 20:33, "Dennis Lee Bieber" <wlfraed at ix.netcom.com> wrote:
> |> Python threads work fine if the threads either rely on intelligent
> |> DLLs for number crunching (instead of doing nested Python loops to
> |> process a numeric array you pass it to something like NumPy which
> |> releases the GIL while crunching a copy of the array) or they do lots of
> |> I/O and have to wait for I/O devices (while one thread is waiting for
> |> the write/read operation to complete, another thread can do some number
> |> crunching).
> |
> | Has nobody thought of a context manager to allow a part of your code to
> | free up the GIL? I think the GIL is not inherently bad, but if it poses a
> | problem at times, there should be a way to get it out of your... Way.
>
> The GIL makes individual python operations thread safe by never
> running two at once. This makes the implementation of the operations
> simpler, faster and safer. It is probably totally infeasible to
> write meaningful python code inside your suggested context
> manager that didn't rely on the GIL; if the GIL were not held the
> code would be unsafe.

I just got my hands dirty trying to synchronize Python prints from many threads.
Sometimes they mess up when printing the newlines. 

I tried several approaches using threading.Lock and Condition. None of them worked perfectly and all of them made the code sluggish. 

Is there a 100% sure method to make print thread safe? Can it be fast???


> It is easy for a C extension to release the GIL, and then to do
> meaningful work until it needs to return to python land. Most C
> extensions will do that around non-trivial sections, and anything
> that may stall in the OS.
>
> So your use case for the context manager doesn't fit well.
> --
> Cameron Simpson <cs at zip.com.au>
>
> Gentle suggestions being those which are written on rocks of less than 5lbs.
> - Tracy Nelson in comp.lang.c
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From cs at zip.com.au  Mon May 20 04:35:20 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 20 May 2013 18:35:20 +1000
Subject: Please help with Threading
In-Reply-To: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>
References: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>
Message-ID: <20130520083520.GA64848@cskk.homeip.net>

On 20May2013 10:53, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
| I just got my hands dirty trying to synchronize Python prints from many threads.
| Sometimes they mess up when printing the newlines. 
| I tried several approaches using threading.Lock and Condition.
| None of them worked perfectly and all of them made the code sluggish.

Show us some code, with specific complaints.

Did you try this?

  _lock = Lock()

  def lprint(*a, **kw):
    global _lock
    with _lock:
      print(*a, **kw)

and use lprint() everywhere?

For generality the lock should be per file: the above hack uses one
lock for any file, so that's going to stall overlapping prints to
different files; inefficient.

There are other things than the above, but at least individual prints will
never overlap. If you have interleaved prints, show us.

| Is there a 100% sure method to make print thread safe? Can it be fast???

Depends on what you mean by "fast". It will be slower than code
with no lock; how much would require measurement.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

My own suspicion is that the universe is not only queerer than we suppose,
but queerer than we *can* suppose.
        - J.B.S. Haldane "On Being the Right Size"
          in the (1928) book "Possible Worlds"


From rosuav at gmail.com  Mon May 20 05:09:13 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 20 May 2013 19:09:13 +1000
Subject: Please help with Threading
In-Reply-To: <20130520083520.GA64848@cskk.homeip.net>
References: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>
	<20130520083520.GA64848@cskk.homeip.net>
Message-ID: <CAPTjJmoxaieL-kwTfuHBV=jDeLpLF2=W8mzx7sv=83MwTDGZQw@mail.gmail.com>

On Mon, May 20, 2013 at 6:35 PM, Cameron Simpson <cs at zip.com.au> wrote:
>   _lock = Lock()
>
>   def lprint(*a, **kw):
>     global _lock
>     with _lock:
>       print(*a, **kw)
>
> and use lprint() everywhere?

Fun little hack:

def print(*args,print=print,lock=Lock(),**kwargs):
  with lock:
    print(*args,**kwargs)

Question: Is this a cool use or a horrible abuse of the scoping rules?

ChrisA


From fabiosantosart at gmail.com  Mon May 20 05:26:20 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 20 May 2013 10:26:20 +0100
Subject: Please help with Threading
In-Reply-To: <CAPTjJmoxaieL-kwTfuHBV=jDeLpLF2=W8mzx7sv=83MwTDGZQw@mail.gmail.com>
References: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>
	<20130520083520.GA64848@cskk.homeip.net>
	<CAPTjJmoxaieL-kwTfuHBV=jDeLpLF2=W8mzx7sv=83MwTDGZQw@mail.gmail.com>
Message-ID: <CAA=1kxS9h+c46KDoTK2-+y-uSWPDn5vFqMFNyUm3H=ZuATnwhQ@mail.gmail.com>

It is pretty cool although it looks like a recursive function at first ;)
On 20 May 2013 10:13, "Chris Angelico" <rosuav at gmail.com> wrote:

> On Mon, May 20, 2013 at 6:35 PM, Cameron Simpson <cs at zip.com.au> wrote:
> >   _lock = Lock()
> >
> >   def lprint(*a, **kw):
> >     global _lock
> >     with _lock:
> >       print(*a, **kw)
> >
> > and use lprint() everywhere?
>
> Fun little hack:
>
> def print(*args,print=print,lock=Lock(),**kwargs):
>   with lock:
>     print(*args,**kwargs)
>
> Question: Is this a cool use or a horrible abuse of the scoping rules?
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From cs at zip.com.au  Mon May 20 05:54:19 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 20 May 2013 19:54:19 +1000
Subject: Please help with Threading
In-Reply-To: <CAPTjJmoxaieL-kwTfuHBV=jDeLpLF2=W8mzx7sv=83MwTDGZQw@mail.gmail.com>
References: <CAPTjJmoxaieL-kwTfuHBV=jDeLpLF2=W8mzx7sv=83MwTDGZQw@mail.gmail.com>
Message-ID: <20130520095419.GA14050@cskk.homeip.net>

On 20May2013 19:09, Chris Angelico <rosuav at gmail.com> wrote:
| On Mon, May 20, 2013 at 6:35 PM, Cameron Simpson <cs at zip.com.au> wrote:
| >   _lock = Lock()
| >
| >   def lprint(*a, **kw):
| >     global _lock
| >     with _lock:
| >       print(*a, **kw)
| >
| > and use lprint() everywhere?
| 
| Fun little hack:
| 
| def print(*args,print=print,lock=Lock(),**kwargs):
|   with lock:
|     print(*args,**kwargs)
| 
| Question: Is this a cool use or a horrible abuse of the scoping rules?

I carefully avoided monkey patching print itself:-)

That's... mad! I can see what the end result is meant to be, but
it looks like a debugging nightmare. Certainly my scoping-fu is too
weak to see at a glance how it works.
-- 
Cameron Simpson <cs at zip.com.au>

I will not do it as a hack       I will not do it for my friends
I will not do it on a Mac        I will not write for Uncle Sam
I will not do it on weekends     I won't do ADA, Sam-I-Am
        - Gregory Bond <gnb at bby.com.au>


From rosuav at gmail.com  Mon May 20 06:09:13 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 20 May 2013 20:09:13 +1000
Subject: Please help with Threading
In-Reply-To: <20130520095419.GA14050@cskk.homeip.net>
References: <CAPTjJmoxaieL-kwTfuHBV=jDeLpLF2=W8mzx7sv=83MwTDGZQw@mail.gmail.com>
	<20130520095419.GA14050@cskk.homeip.net>
Message-ID: <CAPTjJmrEW5x0V=yju-R820Bume81HMNEHhauK0O4S6PB7mNO=A@mail.gmail.com>

On Mon, May 20, 2013 at 7:54 PM, Cameron Simpson <cs at zip.com.au> wrote:
> On 20May2013 19:09, Chris Angelico <rosuav at gmail.com> wrote:
> | On Mon, May 20, 2013 at 6:35 PM, Cameron Simpson <cs at zip.com.au> wrote:
> | >   _lock = Lock()
> | >
> | >   def lprint(*a, **kw):
> | >     global _lock
> | >     with _lock:
> | >       print(*a, **kw)
> | >
> | > and use lprint() everywhere?
> |
> | Fun little hack:
> |
> | def print(*args,print=print,lock=Lock(),**kwargs):
> |   with lock:
> |     print(*args,**kwargs)
> |
> | Question: Is this a cool use or a horrible abuse of the scoping rules?
>
> I carefully avoided monkey patching print itself:-)
>
> That's... mad! I can see what the end result is meant to be, but
> it looks like a debugging nightmare. Certainly my scoping-fu is too
> weak to see at a glance how it works.

Hehe. Like I said, could easily be called abuse.

Referencing a function's own name in a default has to have one of
these interpretations:

1) It's a self-reference, which can be used to guarantee recursion
even if the name is rebound
2) It references whatever previously held that name before this def statement.

Either would be useful. Python happens to follow #2; though I can't
point to any piece of specification that mandates that, so all I can
really say is that CPython 3.3 appears to follow #2. But both
interpretations make sense, and both would be of use, and use of
either could be called abusive of the rules. Figure that out. :)

The second defaulted argument (lock=Lock()), of course, is a common
idiom. No abuse there, that's pretty Pythonic.

This same sort of code could be done as a decorator:

def serialize(fn):
	lock=Lock()
	def locked(*args,**kw):
		with lock:
			fn(*args,**kw)
	return locked

print=serialize(print)

Spelled like this, it's obvious that the argument to serialize has to
be the previous 'print'. The other notation achieves the same thing,
just in a quirkier way :)

ChrisA


From ned at nedbatchelder.com  Mon May 20 06:46:38 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Mon, 20 May 2013 06:46:38 -0400
Subject: Please help with Threading
In-Reply-To: <CAPTjJmrEW5x0V=yju-R820Bume81HMNEHhauK0O4S6PB7mNO=A@mail.gmail.com>
References: <CAPTjJmoxaieL-kwTfuHBV=jDeLpLF2=W8mzx7sv=83MwTDGZQw@mail.gmail.com>
	<20130520095419.GA14050@cskk.homeip.net>
	<CAPTjJmrEW5x0V=yju-R820Bume81HMNEHhauK0O4S6PB7mNO=A@mail.gmail.com>
Message-ID: <5199FF0E.8000600@nedbatchelder.com>

On 5/20/2013 6:09 AM, Chris Angelico wrote:
> Referencing a function's own name in a default has to have one of
> these interpretations:
>
> 1) It's a self-reference, which can be used to guarantee recursion
> even if the name is rebound
> 2) It references whatever previously held that name before this def statement.

The meaning must be #2.  A def statement is nothing more than a fancy 
assignment statement.  This:

     def foo(a):
         return a + 1

is really just the same as:

     foo = lambda a: a+1

(in fact, they compile to identical bytecode).  More complex def's don't 
have equivalent lambdas, but are still assignments to the name of the 
function.  So your "apparently recursive" print function is no more 
ambiguous "x = x + 1".  The x on the right hand side is the old value of 
x, the x on the left hand side will be the new value of x.

     # Each of these updates a name
     x = x + 1
     def print(*args,print=print,lock=Lock(),**kwargs):
       with lock:
         print(*args,**kwargs)

Of course, if you're going to use that code, a comment might be in order 
to help the next reader through the trickiness...

--Ned.



From rosuav at gmail.com  Mon May 20 10:52:25 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 21 May 2013 00:52:25 +1000
Subject: Please help with Threading
In-Reply-To: <5199FF0E.8000600@nedbatchelder.com>
References: <CAPTjJmoxaieL-kwTfuHBV=jDeLpLF2=W8mzx7sv=83MwTDGZQw@mail.gmail.com>
	<20130520095419.GA14050@cskk.homeip.net>
	<CAPTjJmrEW5x0V=yju-R820Bume81HMNEHhauK0O4S6PB7mNO=A@mail.gmail.com>
	<5199FF0E.8000600@nedbatchelder.com>
Message-ID: <CAPTjJmpBTEOtqgLd_cXuUxYwKKYF57GC4WQgciAYjw9QM2C7qg@mail.gmail.com>

=On Mon, May 20, 2013 at 8:46 PM, Ned Batchelder <ned at nedbatchelder.com> wrote:
> On 5/20/2013 6:09 AM, Chris Angelico wrote:
>>
>> Referencing a function's own name in a default has to have one of
>> these interpretations:
>>
>> 1) It's a self-reference, which can be used to guarantee recursion
>> even if the name is rebound
>> 2) It references whatever previously held that name before this def
>> statement.
>
>
> The meaning must be #2.  A def statement is nothing more than a fancy
> assignment statement.

Sure, but the language could have been specced up somewhat
differently, with the same syntax. I was fairly confident that this
would be universally true (well, can't do it with 'print' per se in
older Pythons, but for others); my statement about CPython 3.3 was
just because I hadn't actually hunted down specification proof.

> So your "apparently recursive" print function is no more
> ambiguous "x = x + 1".  The x on the right hand side is the old value of x,
> the x on the left hand side will be the new value of x.
>
>     # Each of these updates a name
>     x = x + 1
>
>     def print(*args,print=print,lock=Lock(),**kwargs):
>       with lock:
>         print(*args,**kwargs)

Yeah. The decorator example makes that fairly clear.

> Of course, if you're going to use that code, a comment might be in order to
> help the next reader through the trickiness...

Absolutely!!

ChrisA


From carlosnepomuceno at outlook.com  Mon May 20 06:01:13 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 20 May 2013 13:01:13 +0300
Subject: Please help with Threading
In-Reply-To: <20130520083520.GA64848@cskk.homeip.net>
References: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>,
	<20130520083520.GA64848@cskk.homeip.net>
Message-ID: <BLU176-W34EFE633A87FD4E89B622ED7AF0@phx.gbl>

----------------------------------------
> Date: Mon, 20 May 2013 18:35:20 +1000
> From: cs at zip.com.au
> To: carlosnepomuceno at outlook.com
> CC: python-list at python.org
> Subject: Re: Please help with Threading
>
> On 20May2013 10:53, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> | I just got my hands dirty trying to synchronize Python prints from many threads.
> | Sometimes they mess up when printing the newlines.
> | I tried several approaches using threading.Lock and Condition.
> | None of them worked perfectly and all of them made the code sluggish.
>
> Show us some code, with specific complaints.
>
> Did you try this?
>
> _lock = Lock()
>
> def lprint(*a, **kw):
> global _lock
> with _lock:
> print(*a, **kw)
>
> and use lprint() everywhere?


It works! Think I was running the wrong script...

Anyway, the suggestion you've made is the third and latest attempt that I've tried to synchronize the print outputs from the threads.

I've also used:

### 1st approach ###
lock? = threading.Lock()
[...]
try:
??? lock.acquire()
??? [thread protected code]
finally:
??? lock.release()


### 2nd approach ###
cond? = threading.Condition()
[...]
try:
??? [thread protected code]
??? with cond:
? ?? ?? print '[...]'


### 3rd approach ###
from __future__ import print_function

def safe_print(*args, **kwargs):
??? global print_lock
??? with print_lock:
??????? print(*args, **kwargs)
[...]
try:
??? [thread protected code]
??? safe_print('[...]')



Except for the first one all kind of have the same performance. The 
problem was I placed the acquire/release around the whole code block, 
instead of only the print statements.

Thanks a lot! ;)

> For generality the lock should be per file: the above hack uses one
> lock for any file, so that's going to stall overlapping prints to
> different files; inefficient.
>
> There are other things than the above, but at least individual prints will
> never overlap. If you have interleaved prints, show us.
>
> | Is there a 100% sure method to make print thread safe? Can it be fast???
>
> Depends on what you mean by "fast". It will be slower than code
> with no lock; how much would require measurement.
>
> Cheers,
> --
> Cameron Simpson <cs at zip.com.au>
>
> My own suspicion is that the universe is not only queerer than we suppose,
> but queerer than we *can* suppose.
> - J.B.S. Haldane "On Being the Right Size"
> in the (1928) book "Possible Worlds" 		 	   		  

From dihedral88888 at googlemail.com  Mon May 20 21:44:46 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Mon, 20 May 2013 18:44:46 -0700 (PDT)
Subject: Please help with Threading
In-Reply-To: <mailman.1879.1369040963.3114.python-list@python.org>
References: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>
	<20130520083520.GA64848@cskk.homeip.net>
	<mailman.1879.1369040963.3114.python-list@python.org>
Message-ID: <b07027cc-5691-42a5-9848-8f985aa356a1@googlegroups.com>

Chris Angelico? 2013?5?20????UTC+8??5?09?13????
> On Mon, May 20, 2013 at 6:35 PM, Cameron Simpson <cs at zip.com.au> wrote:
> 
> >   _lock = Lock()
> 
> >
> 
> >   def lprint(*a, **kw):
> 
> >     global _lock
> 
> >     with _lock:
> 
> >       print(*a, **kw)
> 
> >
> 
> > and use lprint() everywhere?
> 
> 
> 
> Fun little hack:
> 
> 
> 
> def print(*args,print=print,lock=Lock(),**kwargs):
> 
>   with lock:
> 
>     print(*args,**kwargs)
> 
> 
> 
> Question: Is this a cool use or a horrible abuse of the scoping rules?
> 
> 
> 
> ChrisA

OK, if the python interpreter has a global hiden print out
buffer of ,say, 2to 16 K bytes, and all  string print functions
just construct the output string from the format to this string 
in an efficient low level way, then the next question 
would be that whether the uses can use functions in this 
low level buffer for other string formatting jobs.



From rosuav at gmail.com  Mon May 20 21:50:17 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 21 May 2013 11:50:17 +1000
Subject: Please help with Threading
In-Reply-To: <b07027cc-5691-42a5-9848-8f985aa356a1@googlegroups.com>
References: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>
	<20130520083520.GA64848@cskk.homeip.net>
	<mailman.1879.1369040963.3114.python-list@python.org>
	<b07027cc-5691-42a5-9848-8f985aa356a1@googlegroups.com>
Message-ID: <CAPTjJmq9mwNrmXahF=4MiGbJmSMGABuB_J8AOsVErQ4vcjYbhg@mail.gmail.com>

On Tue, May 21, 2013 at 11:44 AM, 88888 Dihedral
<dihedral88888 at googlemail.com> wrote:
> OK, if the python interpreter has a global hiden print out
> buffer of ,say, 2to 16 K bytes, and all  string print functions
> just construct the output string from the format to this string
> in an efficient low level way, then the next question
> would be that whether the uses can use functions in this
> low level buffer for other string formatting jobs.

You remind me of George.
http://www.chroniclesofgeorge.com/

Both make great reading when I'm at work and poking around with random
stuff in our .SQL file of carefully constructed mayhem.

ChrisA


From carlosnepomuceno at outlook.com  Mon May 20 22:53:46 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 21 May 2013 05:53:46 +0300
Subject: Please help with Threading
In-Reply-To: <CAPTjJmq9mwNrmXahF=4MiGbJmSMGABuB_J8AOsVErQ4vcjYbhg@mail.gmail.com>
References: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>,
	<20130520083520.GA64848@cskk.homeip.net>,
	<mailman.1879.1369040963.3114.python-list@python.org>,
	<b07027cc-5691-42a5-9848-8f985aa356a1@googlegroups.com>,
	<CAPTjJmq9mwNrmXahF=4MiGbJmSMGABuB_J8AOsVErQ4vcjYbhg@mail.gmail.com>
Message-ID: <BLU176-W28EE1002FA3448F0B07B63D7A80@phx.gbl>

sys.stdout.write() does not suffer from the newlines mess up when printing from many threads, like print statement does.

The only usage difference, AFAIK, is to add '\n' at the end of the string.

It's faster and thread safe (really?) by default.

BTW, why I didn't find the source code to the sys module in the 'Lib' directory?

----------------------------------------
> Date: Tue, 21 May 2013 11:50:17 +1000
> Subject: Re: Please help with Threading
> From: rosuav at gmail.com
> To: python-list at python.org
>
> On Tue, May 21, 2013 at 11:44 AM, 88888 Dihedral
> <dihedral88888 at googlemail.com> wrote:
>> OK, if the python interpreter has a global hiden print out
>> buffer of ,say, 2to 16 K bytes, and all string print functions
>> just construct the output string from the format to this string
>> in an efficient low level way, then the next question
>> would be that whether the uses can use functions in this
>> low level buffer for other string formatting jobs.
>
> You remind me of George.
> http://www.chroniclesofgeorge.com/
>
> Both make great reading when I'm at work and poking around with random
> stuff in our .SQL file of carefully constructed mayhem.
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From carlosnepomuceno at outlook.com  Mon May 20 23:36:02 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 21 May 2013 06:36:02 +0300
Subject: Please help with Threading
In-Reply-To: <CAPTjJmq9mwNrmXahF=4MiGbJmSMGABuB_J8AOsVErQ4vcjYbhg@mail.gmail.com>
References: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>,
	<20130520083520.GA64848@cskk.homeip.net>,
	<mailman.1879.1369040963.3114.python-list@python.org>,
	<b07027cc-5691-42a5-9848-8f985aa356a1@googlegroups.com>,
	<CAPTjJmq9mwNrmXahF=4MiGbJmSMGABuB_J8AOsVErQ4vcjYbhg@mail.gmail.com>
Message-ID: <BLU176-W31719A6563162A977BB6ADD7A80@phx.gbl>

> On Tue, May 21, 2013 at 11:44 AM, 88888 Dihedral
> <dihedral88888 at googlemail.com> wrote:
>> OK, if the python interpreter has a global hiden print out
>> buffer of ,say, 2to 16 K bytes, and all string print functions
>> just construct the output string from the format to this string
>> in an efficient low level way, then the next question
>> would be that whether the uses can use functions in this
>> low level buffer for other string formatting jobs.
>
> You remind me of George.
> http://www.chroniclesofgeorge.com/
>
> Both make great reading when I'm at work and poking around with random
> stuff in our .SQL file of carefully constructed mayhem.
>
> ChrisA


lol I need more cowbell!!! Please!!! lol 		 	   		  

From steve+comp.lang.python at pearwood.info  Tue May 21 00:48:31 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 21 May 2013 04:48:31 GMT
Subject: Please help with Threading
References: <BLU176-W35F36D9889C0783E544921D7AF0@phx.gbl>
	<20130520083520.GA64848@cskk.homeip.net>
	<mailman.1879.1369040963.3114.python-list@python.org>
	<b07027cc-5691-42a5-9848-8f985aa356a1@googlegroups.com>
	<CAPTjJmq9mwNrmXahF=4MiGbJmSMGABuB_J8AOsVErQ4vcjYbhg@mail.gmail.com>
	<mailman.1898.1369104896.3114.python-list@python.org>
Message-ID: <519afc9e$0$6574$c3e8da3$5496439d@news.astraweb.com>

On Tue, 21 May 2013 05:53:46 +0300, Carlos Nepomuceno wrote:

> BTW, why I didn't find the source code to the sys module in the 'Lib'
> directory?

Because sys is a built-in module. It is embedded in the Python 
interpreter.

-- 
Steven


From fabiosantosart at gmail.com  Mon May 20 03:55:22 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 20 May 2013 08:55:22 +0100
Subject: Please help with Threading
In-Reply-To: <20130520074514.GA33353@cskk.homeip.net>
References: <CAA=1kxR4GD1xLBPJK9sKb_LrVbi-UScBxRbx2vacM989K+YV2Q@mail.gmail.com>
	<20130520074514.GA33353@cskk.homeip.net>
Message-ID: <CAA=1kxSaWQrP+J7ArA8ZW6W6p225q+tsBjRKSuB8hMPBaphaNQ@mail.gmail.com>

My use case was a tight loop processing an image pixel by pixel, or
crunching a CSV file. If it only uses local variables (and probably hold a
lock before releasing the GIL) it should be safe, no?

My idea is that it's a little bad to have to write C or use multiprocessing
just to do simultaneous calculations. I think an application using a
reactor loop such as twisted would actually benefit from this. Sure, it
will be slower than a C implementation of the same loop, but isn't fast
prototyping a very important feature of the Python language?
On 20 May 2013 08:45, "Cameron Simpson" <cs at zip.com.au> wrote:

> On 20May2013 07:25, F?bio Santos <fabiosantosart at gmail.com> wrote:
> | On 18 May 2013 20:33, "Dennis Lee Bieber" <wlfraed at ix.netcom.com> wrote:
> | >         Python threads work fine if the threads either rely on
> intelligent
> | > DLLs for number crunching (instead of doing nested Python loops to
> | > process a numeric array you pass it to something like NumPy which
> | > releases the GIL while crunching a copy of the array) or they do lots
> of
> | > I/O and have to wait for I/O devices (while one thread is waiting for
> | > the write/read operation to complete, another thread can do some number
> | > crunching).
> |
> | Has nobody thought of a context manager to allow a part of your code to
> | free up the GIL? I think the GIL is not inherently bad, but if it poses a
> | problem at times, there should be a way to get it out of your... Way.
>
> The GIL makes individual python operations thread safe by never
> running two at once. This makes the implementation of the operations
> simpler, faster and safer. It is probably totally infeasible to
> write meaningful python code inside your suggested context
> manager that didn't rely on the GIL; if the GIL were not held the
> code would be unsafe.
>
> It is easy for a C extension to release the GIL, and then to do
> meaningful work until it needs to return to python land. Most C
> extensions will do that around non-trivial sections, and anything
> that may stall in the OS.
>
> So your use case for the context manager doesn't fit well.
> --
> Cameron Simpson <cs at zip.com.au>
>
> Gentle suggestions being those which are written on rocks of less than
> 5lbs.
>         - Tracy Nelson in comp.lang.c
>
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From davea at davea.name  Mon May 20 07:06:04 2013
From: davea at davea.name (Dave Angel)
Date: Mon, 20 May 2013 07:06:04 -0400
Subject: Please help with Threading
In-Reply-To: <CAA=1kxSaWQrP+J7ArA8ZW6W6p225q+tsBjRKSuB8hMPBaphaNQ@mail.gmail.com>
References: <CAA=1kxR4GD1xLBPJK9sKb_LrVbi-UScBxRbx2vacM989K+YV2Q@mail.gmail.com>
	<20130520074514.GA33353@cskk.homeip.net>
	<CAA=1kxSaWQrP+J7ArA8ZW6W6p225q+tsBjRKSuB8hMPBaphaNQ@mail.gmail.com>
Message-ID: <519A039C.5040606@davea.name>

On 05/20/2013 03:55 AM, F?bio Santos wrote:
> My use case was a tight loop processing an image pixel by pixel, or
> crunching a CSV file. If it only uses local variables (and probably hold a
> lock before releasing the GIL) it should be safe, no?
>

Are you making function calls, using system libraries, or creating or 
deleting any objects?  All of these use the GIL because they use common 
data structures shared among all threads.  At the lowest level, creating 
an object requires locked access to the memory manager.


Don't forget, the GIL gets used much more for Python internals than it 
does for the visible stuff.


-- 
DaveA


From fabiosantosart at gmail.com  Mon May 20 14:04:50 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 20 May 2013 19:04:50 +0100
Subject: Please help with Threading
In-Reply-To: <519A039C.5040606@davea.name>
References: <CAA=1kxR4GD1xLBPJK9sKb_LrVbi-UScBxRbx2vacM989K+YV2Q@mail.gmail.com>
	<20130520074514.GA33353@cskk.homeip.net>
	<CAA=1kxSaWQrP+J7ArA8ZW6W6p225q+tsBjRKSuB8hMPBaphaNQ@mail.gmail.com>
	<519A039C.5040606@davea.name>
Message-ID: <CAA=1kxTQ=cLN7HN8NQeipOrBJ10PCmRWeSJaU7y9E4QoFr7SAQ@mail.gmail.com>

I didn't know that.
On 20 May 2013 12:10, "Dave Angel" <davea at davea.name> wrote:
> Are you making function calls, using system libraries, or creating or
deleting any objects?  All of these use the GIL because they use common
data structures shared among all threads.  At the lowest level, creating an
object requires locked access to the memory manager.
>
>
> Don't forget, the GIL gets used much more for Python internals than it
does for the visible stuff.

I did not know that. It's both interesting and somehow obvious, although I
didn't know it yet.
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From avnesh.nitk at gmail.com  Sat May 18 06:12:30 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Sat, 18 May 2013 03:12:30 -0700 (PDT)
Subject: python script is not running
Message-ID: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>

hi,
    i want to run python script which generating data into json fromat, I am using crontab, but it's not executing...
my python code--
try.py --

import json
import simplejson as json
import sys

def tryJson():
    saved = sys.stdout
    correctFile = file('data.json', 'a+')
    sys.stdout = correctFile
    result = []
    i = 1
    for i in range(5):
        info = {
                'a': i+1,
                'b': i+2,
                'c': i+3,
               }
        result.append(info)

    if result:
        print json.dumps(result, indent=6)
        sys.stdout = saved
        correctFile.close()
tryJson()

now i m doing ion terminal-
avin at hp:~$ crontab -e
then type -
*/2 * * * * python /home/avin/data/try.py

and save

but it's not executing.


From fjctlzy at gmail.com  Sat May 18 07:18:40 2013
From: fjctlzy at gmail.com (fjctlzy at gmail.com)
Date: Sat, 18 May 2013 19:18:40 +0800
Subject: python script is not running
Message-ID: <e9qp5tf12krh5ivoe56q7im5.1368873342080@email.android.com>

make sure data.json is absolute path
make sure you test it directly without crontab 
in the crontab, execute the script in such way, python scripty > /tmp/log 2>&1 check the log 



????????

Avnesh Shakya <avnesh.nitk at gmail.com>???

>hi,
>    i want to run python script which generating data into json fromat, I am using crontab, but it's not executing...
>my python code--
>try.py --
>
>import json
>import simplejson as json
>import sys
>
>def tryJson():
>    saved = sys.stdout
>    correctFile = file('data.json', 'a+')
>    sys.stdout = correctFile
>    result = []
>    i = 1
>    for i in range(5):
>        info = {
>                'a': i+1,
>                'b': i+2,
>                'c': i+3,
>               }
>        result.append(info)
>
>    if result:
>        print json.dumps(result, indent=6)
>        sys.stdout = saved
>        correctFile.close()
>tryJson()
>
>now i m doing ion terminal-
>avin at hp:~$ crontab -e
>then type -
>*/2 * * * * python /home/avin/data/try.py
>
>and save
>
>but it's not executing.
>-- 
>http://mail.python.org/mailman/listinfo/python-list

From rosuav at gmail.com  Sat May 18 09:28:03 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 18 May 2013 23:28:03 +1000
Subject: python script is not running
In-Reply-To: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>
References: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>
Message-ID: <CAPTjJmpESD5+AumJ=uf01jbFTDO3rWt7Jz932NG0Qgc9prj5eA@mail.gmail.com>

On Sat, May 18, 2013 at 8:12 PM, Avnesh Shakya <avnesh.nitk at gmail.com> wrote:
> avin at hp:~$ crontab -e
> then type -
> */2 * * * * python /home/avin/data/try.py
>

You may need to put an explicit path to your Python interpreter. Type:

$ which python

and put that into your crontab.

ChrisA


From roy at panix.com  Sat May 18 09:44:25 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 18 May 2013 09:44:25 -0400
Subject: python script is not running
References: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>
	<mailman.1801.1368883685.3114.python-list@python.org>
Message-ID: <roy-FB5354.09442518052013@news.panix.com>

In article <mailman.1801.1368883685.3114.python-list at python.org>,
 Chris Angelico <rosuav at gmail.com> wrote:

> On Sat, May 18, 2013 at 8:12 PM, Avnesh Shakya <avnesh.nitk at gmail.com> wrote:
> > avin at hp:~$ crontab -e
> > then type -
> > */2 * * * * python /home/avin/data/try.py
> >
> 
> You may need to put an explicit path to your Python interpreter. Type:
> 
> $ which python
> 
> and put that into your crontab.

True.  Somewhat more generally, jobs run under cron have a far more 
barren environment than most people realize.  Or, looking at it a 
different way, most people don't even realize all the ways they depend 
on their environment being set up properly by the login process.

If you've set things like PYTHONPATH, you won't have them set right for 
cron jobs unless you explicitly reset them in your crontab.

It's often instructive to run something like "env > /tmp/xxx" under 
cron, and compare that to what you get when you run "env" at a 
command-line prompt.


From tjreedy at udel.edu  Sat May 18 12:35:19 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sat, 18 May 2013 12:35:19 -0400
Subject: python script is not running
In-Reply-To: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>
References: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>
Message-ID: <kn8aju$t8f$1@ger.gmane.org>

On 5/18/2013 6:12 AM, Avnesh Shakya wrote:
> hi,
>      i want to run python script which generating data into json fromat, I am using crontab, but it's not executing...
> my python code--
> try.py --
>
> import json
> import simplejson as json
> import sys
>
> def tryJson():
>      saved = sys.stdout
>      correctFile = file('data.json', 'a+')
>      sys.stdout = correctFile

Don't need to change stdout.

>      result = []
>      i = 1
>      for i in range(5):
>          info = {
>                  'a': i+1,
>                  'b': i+2,
>                  'c': i+3,
>                 }
>          result.append(info)

What is you want to add print result for debugging?

>      if result:
>          print json.dumps(result, indent=6)

Either use print >> correctFile, correctFile.write (do you really want 
the extra '\n' that print adds?), or, do the future import of print as 
function and pass correctFile as the file argument

>          sys.stdout = saved
>          correctFile.close()
> tryJson()




From woooee at gmail.com  Sat May 18 13:35:23 2013
From: woooee at gmail.com (woooee)
Date: Sat, 18 May 2013 10:35:23 -0700 (PDT)
Subject: python script is not running
References: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>
Message-ID: <185557b8-5cd0-4e9c-8c6d-855a8635492c@pd6g2000pbc.googlegroups.com>

The obvious question, do you have the shebang on the first line so the
OS knows it's to be run as a Python program?  Also I would change
tryJson() to
if __name__ == "__main__':
    tryJson()
This probably won't make any difference but you will have the bases
covered.



From rosuav at gmail.com  Sat May 18 13:59:12 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 19 May 2013 03:59:12 +1000
Subject: python script is not running
In-Reply-To: <185557b8-5cd0-4e9c-8c6d-855a8635492c@pd6g2000pbc.googlegroups.com>
References: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>
	<185557b8-5cd0-4e9c-8c6d-855a8635492c@pd6g2000pbc.googlegroups.com>
Message-ID: <CAPTjJmr3xVgEXO_1YnAk1jHVjyBR753iWFq6QaBrYvnJMwiXxQ@mail.gmail.com>

On Sun, May 19, 2013 at 3:35 AM, woooee <woooee at gmail.com> wrote:
> The obvious question, do you have the shebang on the first line so the
> OS knows it's to be run as a Python program?

That won't make any difference; the cron job specifically stipulates
the interpreter. It just needs to be done with a full path.

ChrisA


From vincent.vandevyvre at swing.be  Sat May 18 14:43:00 2013
From: vincent.vandevyvre at swing.be (Vincent Vande Vyvre)
Date: Sat, 18 May 2013 20:43:00 +0200
Subject: python script is not running
In-Reply-To: <CAPTjJmr3xVgEXO_1YnAk1jHVjyBR753iWFq6QaBrYvnJMwiXxQ@mail.gmail.com>
References: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>
	<185557b8-5cd0-4e9c-8c6d-855a8635492c@pd6g2000pbc.googlegroups.com>
	<CAPTjJmr3xVgEXO_1YnAk1jHVjyBR753iWFq6QaBrYvnJMwiXxQ@mail.gmail.com>
Message-ID: <5197CBB4.4020501@swing.be>

Le 18/05/2013 19:59, Chris Angelico a ?crit :
> On Sun, May 19, 2013 at 3:35 AM, woooee <woooee at gmail.com> wrote:
>> The obvious question, do you have the shebang on the first line so the
>> OS knows it's to be run as a Python program?
> That won't make any difference; the cron job specifically stipulates
> the interpreter. It just needs to be done with a full path.
>
> ChrisA
Not necessary, I use crontab without problem with this line:

25 16 18 5 * export DISPLAY=:0 & LC_CTYPE="fr_FR.utf-8" 
Lang="fr_FR.utf-8" python /usr/bin/qarte -a 1

... on Ubuntu.

-- 
Vincent V.V.
Oqapy <https://launchpad.net/oqapy> . Qarte 
<https://launchpad.net/qarte> . PaQager <https://launchpad.net/paqager>


From rosuav at gmail.com  Sat May 18 19:33:43 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 19 May 2013 09:33:43 +1000
Subject: python script is not running
In-Reply-To: <5197CBB4.4020501@swing.be>
References: <bb111639-6a94-4151-a153-9bbebe75a4ea@googlegroups.com>
	<185557b8-5cd0-4e9c-8c6d-855a8635492c@pd6g2000pbc.googlegroups.com>
	<CAPTjJmr3xVgEXO_1YnAk1jHVjyBR753iWFq6QaBrYvnJMwiXxQ@mail.gmail.com>
	<5197CBB4.4020501@swing.be>
Message-ID: <CAPTjJmouku86Ra3XbJFv0Z8uZqAHzohmHnKC76HywrWrjfY0OQ@mail.gmail.com>

On Sun, May 19, 2013 at 4:43 AM, Vincent Vande Vyvre
<vincent.vandevyvre at swing.be> wrote:
> Le 18/05/2013 19:59, Chris Angelico a ?crit :
>
>> On Sun, May 19, 2013 at 3:35 AM, woooee <woooee at gmail.com> wrote:
>>>
>>> The obvious question, do you have the shebang on the first line so the
>>> OS knows it's to be run as a Python program?
>>
>> That won't make any difference; the cron job specifically stipulates
>> the interpreter. It just needs to be done with a full path.
>>
>> ChrisA
>
> Not necessary, I use crontab without problem with this line:
>
> 25 16 18 5 * export DISPLAY=:0 & LC_CTYPE="fr_FR.utf-8" Lang="fr_FR.utf-8"
> python /usr/bin/qarte -a 1
>
> ... on Ubuntu.

Everything's configurable. I'd like to hear back from the OP though;
as Roy said, checking 'env' from a cron job will reveal much.

ChrisA


From li.beinan at gmail.com  Sat May 18 10:03:02 2013
From: li.beinan at gmail.com (Beinan Li)
Date: Sat, 18 May 2013 10:03:02 -0400
Subject: Future standard GUI library
Message-ID: <CAPbpa4QQf1NZd-0-GDH=wjBMApBmh5=FXfWxFp28dngbXrPWWQ@mail.gmail.com>

Not sure if this is the right place to talk about this. Even less sure if I
can
move this discussion to tkinter list, so here I am...

I know this may sound a silly question because no one can see the future.
But ...
Do you think tkinter is going to be the standard python built-in gui
solution as long as python exists?

I couldn't help but wonder if wx or PySide receives better py2 and py3
support, or anything else that prevent
them from getting into the standard python distributions, whether or not
this scene could start to shift ...

I believe this "which one of tkinter, wx, qt, is the best gui toolkit for
python" flame war has been going on
for ages. I love the fact that python ships a built-in gui solution which
makes shipping a pure-python desktop
application a viable choice. But tkinter does not appear to be the most
time-saving way to write a gui app.
The layout designer support, for one, is next to zero. I tried many
3rd-party designers
and loved PAGE (http://page.sourceforge.net) for a few minutes, then came
the author's comment:

"For release 4.0, I spent about two months working with the ?Theme? part of
Ttk and have had only partial success. I now believe that the ?Theme? part
of Ttk is really a very poor piece of software at all levels - concept,
implementation, and especially documentation. My guess is if it had been
well documented it would have been recognized by even the author as junk. I
find it hard to believe that the people who control Tcl/Tk allowed it in
the code base. I continue to support ttk because of the paned window,
notebook and treeview widgets."

And ttk seems to be a major attraction that keeps people coming back to tk
for the looks. This worries me very much
about whether I should start a gui app using python. Because if ttk is not
a "mature" technology, I'd avoid premature adoption.
If ttk is out of the question, tkinter will be too. I'd then be forced to
use a 3rd-party solution like wx or qt, which I really don't want to see.

Anyways, this is just some concerns that I hope someone may give his/her
opinions about.

Thanks!
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From kw at codebykevin.com  Sat May 18 11:32:04 2013
From: kw at codebykevin.com (Kevin Walzer)
Date: Sat, 18 May 2013 11:32:04 -0400
Subject: Future standard GUI library
In-Reply-To: <mailman.1803.1368885785.3114.python-list@python.org>
References: <mailman.1803.1368885785.3114.python-list@python.org>
Message-ID: <kn86m8$pdl$1@dont-email.me>

Hello,

On 5/18/13 10:03 AM, Beinan Li wrote:

> I know this may sound a silly question because no one can see the
> future. But ...
> Do you think tkinter is going to be the standard python built-in gui
> solution as long as python exists?

I don't see any significant clamoring among the Python core developers 
to make a change.

>
> I couldn't help but wonder if wx or PySide receives better py2 and py3
> support, or anything else that prevent
> them from getting into the standard python distributions, whether or not
> this scene could start to shift ...

I am not going to engage in the old UI toolkit flame ware; I will limit 
myself to factual observations and a few opinions about Tkinter without 
placing it against other toolkits.

Python has the PEP process for suggesting changes to the core language 
and libraries. Changing the default UI toolkit would require someone to 
submit a proposal, get it approved, provide the implementation, and 
commit to maintaining the implementation over the long term. You propose 
it, you own it.

Thus far no one has done this. I would think the only person who would 
be in a position to propose wxPython would be Robin Dunn since he is the 
primary copyright holder, and to my knowledge he has never done so. As 
for Pyside, it was not part of the transition of Qt from Nokia to Digia, 
and so it appears to be orphaned. PyQt might be an alternative, but I 
don't think Phil Thompson would ever submit it, as it would likely 
affect his livelihood.

Given these facts, it's safe to say that Tkinter will remain the default 
GUI toolkit in the stdlib for some years to come.

>
> I believe this "which one of tkinter, wx, qt, is the best gui toolkit
> for python" flame war has been going on
> for ages. I love the fact that python ships a built-in gui solution
> which makes shipping a pure-python desktop
> application a viable choice. But tkinter does not appear to be the most
> time-saving way to write a gui app.
> The layout designer support, for one, is next to zero. I tried many
> 3rd-party designers
> and loved PAGE (http://page.sourceforge.net) for a few minutes, then
> came the author's comment:

PAGE strikes me as an odd choice for a Python developer to develop a Tk 
UI. It's a descendent of the old Visual Tcl tool, and is run from Tcl 
and not Python. VTcl was always famous for producing a huge pot of 
spaghetti UI code that couldn't be easily modified outside the tool. I 
have also tried many Tk UI tools including VTcl, SpecTcl, and the 
orphaned tool from ActiveState, and have concluded that writing my own 
code is both simpler and faster. As always, your mileage may vary.

>
> "For release 4.0, I spent about two months working with the ?Theme? part
> of Ttk and have had only partial success. I now believe that the ?Theme?
> part of Ttk is really a very poor piece of software at all levels -
> concept, implementation, and especially documentation. My guess is if it
> had been well documented it would have been recognized by even the
> author as junk. I find it hard to believe that the people who control
> Tcl/Tk allowed it in the code base. I continue to support ttk because of
> the paned window, notebook and treeview widgets."

The implementation of the ttk widgets is quite complex--that, in turn, 
makes their documentation complex, and the complexity is a drawback. 
It's hard to customize the ttk themes, especially compared to 
customizing standard Tk widgets. I'm one of the core Tk developers, and 
I don't fully understand the themed widgets' internals or how to 
customize them. But it's not fair to say that they are "junk." The 
author of PAGE may think so, but many would disagree. I think the 
widgets work quite well, especially if used in their default mode. It's 
difficult to overstate the improvement in the look and feel of my Tk 
apps on the Mac when I switched to using the themed widgets.

>
> And ttk seems to be a major attraction that keeps people coming back to
> tk for the looks. This worries me very much
> about whether I should start a gui app using python. Because if ttk is
> not a "mature" technology, I'd avoid premature adoption.
> If ttk is out of the question, tkinter will be too. I'd then be forced
> to use a 3rd-party solution like wx or qt, which I really don't want to see.

ttk is a mature technology. The initial specification, code, and docs 
were developed by Joe English nearly a decade ago (see 
http://tktable.sourceforge.net/tile/tile-tcl2004.pdf), and they had been 
accepted into Tcl/Tk's core in version 8.5 (released in 2007). The 
earliest work on integrating these widgets into Python began in 2008, 
and they were formally released in 2010.  I would say that ttk is 
mature, stable, and unlikely to undergo radical change in the future.

Guilherme Polo has done superb work in integrating the themed widgets 
into Python--it's the most significant UI advance in Python's stdlib in 
years. You are quite safe in developing against this API, unless your 
taste simply does not run to using the ttk widgets.

Hope this helps,
Kevin

-- 
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
http://www.wtmobilesoftware.com


From steve+comp.lang.python at pearwood.info  Sat May 18 17:25:47 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 18 May 2013 21:25:47 GMT
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
Message-ID: <5197f1da$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Sat, 18 May 2013 10:03:02 -0400, Beinan Li wrote:

> Do you think tkinter is going to be the standard python built-in gui
> solution as long as python exists?

Probably.

> I couldn't help but wonder if wx or PySide receives better py2 and py3
> support, or anything else that prevent them from getting into the
> standard python distributions, whether or not this scene could start to
> shift ...

One of the major issues preventing projects being added to the standard 
library is the maintenance schedule. Python's schedule for new releases 
is quite conservative and slow. If, say, wxPython was added to the std 
lib, it would have to follow Python's schedule:

* most backwards incompatible changes would be forbidden;

* those that are allowed would require a minimum of two major releases 
(three years) before removing functionality;

* about four bug-fix releases (I think?) per year.

If a project is used to (say) weekly releases, dropping down to Python's 
schedule can be rather painful.

Once something has been added to the standard library, it more or less 
has to have a stable API, become conservative about changes, and care 
more about backwards-compatibility than new features. Stability and 
consistency become paramount. Many excellent, popular packages cannot 
live under those restrictions, and so will never be part of the standard 
library.

Tkinter is good in this regard, because it is a wrapper around Tk/Tcl, 
which is equally stable and conservative as Python. Possibly even more so.



-- 
Steven


From llanitedave at veawb.coop  Sat May 18 23:01:31 2013
From: llanitedave at veawb.coop (llanitedave)
Date: Sat, 18 May 2013 20:01:31 -0700 (PDT)
Subject: Future standard GUI library
In-Reply-To: <mailman.1803.1368885785.3114.python-list@python.org>
References: <mailman.1803.1368885785.3114.python-list@python.org>
Message-ID: <8c3c3ef4-f861-4363-b331-fec0a5782c45@googlegroups.com>

I'm curious about how commonly tkinter is actually used among Python app developers as compared to wx, Pyside, or PyQT.  I get the impression that more distributed apps are built with wxPython, at least, than tkinter.  My impression is far from actual knowledge, of course.


From kw at codebykevin.com  Sun May 19 08:57:07 2013
From: kw at codebykevin.com (Kevin Walzer)
Date: Sun, 19 May 2013 08:57:07 -0400
Subject: Future standard GUI library
In-Reply-To: <8c3c3ef4-f861-4363-b331-fec0a5782c45@googlegroups.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<8c3c3ef4-f861-4363-b331-fec0a5782c45@googlegroups.com>
Message-ID: <knahvi$bre$1@dont-email.me>

On 5/18/13 11:01 PM, llanitedave wrote:
> I'm curious about how commonly tkinter is actually used among Python app developers as compared to wx, Pyside, or PyQT.  I get the impression that more distributed apps are built with wxPython, at least, than tkinter.  My impression is far from actual knowledge, of course.
>

I have two commercial apps developed with Tkinter:

http://www.codebykevin.com/phynchronicity.html
http://www.codebykevin.com/quickwho.html

--Kevin

-- 
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
http://www.wtmobilesoftware.com


From feliphil at gmx.net  Wed May 22 09:42:33 2013
From: feliphil at gmx.net (Wolfgang Keller)
Date: Wed, 22 May 2013 15:42:33 +0200
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
Message-ID: <20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>

> I know this may sound a silly question because no one can see the
> future. But ...
> Do you think tkinter is going to be the standard python built-in gui
> solution as long as python exists?

"Standard built-in" maybe, but by far most people who need a GUI for an
actual application will keep using something else.
 
> I couldn't help but wonder if wx or PySide receives better py2 and py3
> support, or anything else that prevent
> them from getting into the standard python distributions, whether or
> not this scene could start to shift ...

Didn't Pyside have serious trouble recently, requiring a reanimation of
the project?
 
> I believe this "which one of tkinter, wx, qt, is the best gui toolkit
> for python" flame war has been going on
> for ages. 

If (Py)Qt wasn't so freaking fat, it might be the best.
If wxPython had a more pythonic (and stable?) API, it might be the best.
If PyGTK was more native on Windows and native at all on MacOS X, it
might be the best.
If PyGUI was more extensive, it might be the best.

> This worries me very much about whether I should start a gui app
> using python.

What other open-source cross-platform programming language choices do yo
have.

Java? For GUIs? Excuse me while I vomit.

C++? As a language for human beings? Oops, I have to throw up again.

Sincerely,

Wolfgang


From rosuav at gmail.com  Wed May 22 10:24:15 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 00:24:15 +1000
Subject: Future standard GUI library
In-Reply-To: <20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
Message-ID: <CAPTjJmqOD8eGWW4HmY-eANZ8Tek97BLZT-T=BeOKuKb1-MUWrw@mail.gmail.com>

On Wed, May 22, 2013 at 11:42 PM, Wolfgang Keller <feliphil at gmx.net> wrote:
> What other open-source cross-platform programming language choices do yo
> have.
>
> Java? For GUIs? Excuse me while I vomit.
>
> C++? As a language for human beings? Oops, I have to throw up again.

I personally like using Pike and GTK, so if I were to try a
cross-platform Python GUI project, I'd probably give PyGTK a shot. But
there's another option that is available to every platform and
(practially) every high level language: the web browser. Make your app
serve HTTP and do up your UI in HTML5/CSS3 - your facilities are
pretty extensive. Plus you get networking support for free! Obviously
this option isn't for everyone, but don't discount it out of hand.

ChrisA


From llanitedave at veawb.coop  Wed May 22 22:31:55 2013
From: llanitedave at veawb.coop (llanitedave)
Date: Wed, 22 May 2013 19:31:55 -0700 (PDT)
Subject: Future standard GUI library
In-Reply-To: <mailman.1967.1369232658.3114.python-list@python.org>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
Message-ID: <19c925fc-dbf8-417c-9298-f682c9b2e558@googlegroups.com>

On Wednesday, May 22, 2013 7:24:15 AM UTC-7, Chris Angelico wrote:
> On Wed, May 22, 2013 at 11:42 PM, Wolfgang Keller <feliphil at gmx.net> wrote:
> 
> > What other open-source cross-platform programming language choices do yo
> 
> > have.
> 
> >
> 
> > Java? For GUIs? Excuse me while I vomit.
> 
> >
> 
> > C++? As a language for human beings? Oops, I have to throw up again.
> 
> 
> 
> I personally like using Pike and GTK, so if I were to try a
> 
> cross-platform Python GUI project, I'd probably give PyGTK a shot. But
> 
> there's another option that is available to every platform and
> 
> (practially) every high level language: the web browser. Make your app
> 
> serve HTTP and do up your UI in HTML5/CSS3 - your facilities are
> 
> pretty extensive. Plus you get networking support for free! Obviously
> 
> this option isn't for everyone, but don't discount it out of hand.
> 
> 
> 
> ChrisA

I've been thinking about that myself for some future app ideas.  If you have a stand-alone app working from your web browser, don't you need an embedded web server to utilize the file system?  Is a system like Django for an app overkill?  Or is its embedded development server underkill for a single-user browser-based application?


From fabiosantosart at gmail.com  Thu May 23 02:43:15 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 23 May 2013 07:43:15 +0100
Subject: Future standard GUI library
In-Reply-To: <19c925fc-dbf8-417c-9298-f682c9b2e558@googlegroups.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<19c925fc-dbf8-417c-9298-f682c9b2e558@googlegroups.com>
Message-ID: <CAA=1kxS_U4pyjOA+4Tx8Lc4k4UebxVB1QRbEo4N6qY+3WkCuTg@mail.gmail.com>

On 23 May 2013 03:39, "llanitedave" <llanitedave at veawb.coop> wrote:
>
> On Wednesday, May 22, 2013 7:24:15 AM UTC-7, Chris Angelico wrote:
> > On Wed, May 22, 2013 at 11:42 PM, Wolfgang Keller <feliphil at gmx.net>
wrote:
...
> > there's another option that is available to every platform and
> > (practially) every high level language: the web browser. Make your app
> > serve HTTP and do up your UI in HTML5/CSS3 - your facilities are
> > pretty extensive. Plus you get networking support for free! Obviously
> > this option isn't for everyone, but don't discount it out of hand.
> >
> > ChrisA
>
> I've been thinking about that myself for some future app ideas.  If you
have a stand-alone app working from your web browser, don't you need an
embedded web server to utilize the file system?  Is a system like Django
for an app overkill?  Or is its embedded development server underkill for a
single-user browser-based application?
> --
> http://mail.python.org/mailman/listinfo/python-list

JavaScript has this:

http://appjs.org/

It's a node.js server app serving a folder of plain old HTML files to a
chrome embedded browser.

You can code in a node.js server using anything you like, serve requests
for your client app (or use the server code directly, you can just put the
functions you would like to share with the client in the window object),
etc.

I'm using it for a peer to peer configurable application. To do that I
serve up the web application for me and my peers (by using a regular server
instead of the fake server it comes with), and the browser is just a client
which can connect wherever I want it to.

Someone should fork this and make it work in python.
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From rosuav at gmail.com  Thu May 23 02:48:53 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 16:48:53 +1000
Subject: Future standard GUI library
In-Reply-To: <CAA=1kxS_U4pyjOA+4Tx8Lc4k4UebxVB1QRbEo4N6qY+3WkCuTg@mail.gmail.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<19c925fc-dbf8-417c-9298-f682c9b2e558@googlegroups.com>
	<CAA=1kxS_U4pyjOA+4Tx8Lc4k4UebxVB1QRbEo4N6qY+3WkCuTg@mail.gmail.com>
Message-ID: <CAPTjJmprp5-QiWCjF+ujpSKu8qp5aQtbMY2QnqpMAMmRvBj48A@mail.gmail.com>

On Thu, May 23, 2013 at 4:43 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
> On 23 May 2013 03:39, "llanitedave" <llanitedave at veawb.coop> wrote:
>> On Wednesday, May 22, 2013 7:24:15 AM UTC-7, Chris Angelico wrote:
>> > there's another option that is available to every platform and
>> > (practially) every high level language: the web browser. Make your app
>> > serve HTTP and do up your UI in HTML5/CSS3 - your facilities are
>> > pretty extensive. Plus you get networking support for free! Obviously
>> > this option isn't for everyone, but don't discount it out of hand.
>> >
>> > ChrisA
>>
>> I've been thinking about that myself for some future app ideas.  If you
>> have a stand-alone app working from your web browser, don't you need an
>> embedded web server to utilize the file system?  Is a system like Django for
>> an app overkill?  Or is its embedded development server underkill for a
>> single-user browser-based application?
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
> JavaScript has this:
>
> http://appjs.org/
>
> It's a node.js server app serving a folder of plain old HTML files to a
> chrome embedded browser.
>
> You can code in a node.js server using anything you like, serve requests for
> your client app (or use the server code directly, you can just put the
> functions you would like to share with the client in the window object),
> etc.

Many high level languages today come with simple HTTP server modules.
They may not scale "to infinity and beyond", but they'll work fine for
a single-user system using a browser for its UI. Chances are they'll
do well for everything up to a single CPU core. Depends on the
language and library, of course.

ChrisA


From carlosnepomuceno at outlook.com  Thu May 23 02:58:02 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 09:58:02 +0300
Subject: Future standard GUI library
In-Reply-To: <19c925fc-dbf8-417c-9298-f682c9b2e558@googlegroups.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>,
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>,
	<mailman.1967.1369232658.3114.python-list@python.org>,
	<19c925fc-dbf8-417c-9298-f682c9b2e558@googlegroups.com>
Message-ID: <BLU176-W10E7B03A83D0EC1D9402D8D7AA0@phx.gbl>

You don't! If your app needs local content just use a regular open() (or your browser) to read the files and render them as you see fit.

For remote content you just need the 'urllib2' module or something like 'requests' module to get the data.

----------------------------------------
> Date: Wed, 22 May 2013 19:31:55 -0700
> Subject: Re: Future standard GUI library
> From: llanitedave at veawb.coop
[...]
>
> I've been thinking about that myself for some future app ideas. If you have a stand-alone app working from your web browser, don't you need an embedded web server to utilize the file system? Is a system like Django for an app overkill? Or is its embedded development server underkill for a single-user browser-based application?
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rosuav at gmail.com  Thu May 23 03:03:59 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 17:03:59 +1000
Subject: Future standard GUI library
In-Reply-To: <BLU176-W10E7B03A83D0EC1D9402D8D7AA0@phx.gbl>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<19c925fc-dbf8-417c-9298-f682c9b2e558@googlegroups.com>
	<BLU176-W10E7B03A83D0EC1D9402D8D7AA0@phx.gbl>
Message-ID: <CAPTjJmq1nRCLfTQ_PRtQHTR6nX62jDfLG6dgXmwpN9XT4dOZdA@mail.gmail.com>

On Thu, May 23, 2013 at 4:58 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> You don't! If your app needs local content just use a regular open() (or your browser) to read the files and render them as you see fit.
>
> For remote content you just need the 'urllib2' module or something like 'requests' module to get the data.

BTW, forgot the link. The part you DO need is something like this:

http://docs.python.org/3/library/http.server.html

It takes care of the irrelevant and lets you just write your app. The
same sort of thing is available in quite a few languages. Great for
knocking something together quickly; not designed for thousand-TPS web
servers.

ChrisA


From fabiosantosart at gmail.com  Thu May 23 03:08:12 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 23 May 2013 08:08:12 +0100
Subject: Future standard GUI library
In-Reply-To: <BLU176-W10E7B03A83D0EC1D9402D8D7AA0@phx.gbl>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<19c925fc-dbf8-417c-9298-f682c9b2e558@googlegroups.com>
	<BLU176-W10E7B03A83D0EC1D9402D8D7AA0@phx.gbl>
Message-ID: <CAA=1kxS5TPEZrpUgwdamHFsnj88a2o0k8HDGyi654+U+9O4=dg@mail.gmail.com>

It would be way more practical to have an embedded browser. Appjs doesn't
even occupy a port on the client. We could totally benefit from that.
Django applications practically make themselves.
On 23 May 2013 08:02, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
wrote:

> You don't! If your app needs local content just use a regular open() (or
> your browser) to read the files and render them as you see fit.
>
> For remote content you just need the 'urllib2' module or something like
> 'requests' module to get the data.
>
> ----------------------------------------
> > Date: Wed, 22 May 2013 19:31:55 -0700
> > Subject: Re: Future standard GUI library
> > From: llanitedave at veawb.coop
> [...]
> >
> > I've been thinking about that myself for some future app ideas. If you
> have a stand-alone app working from your web browser, don't you need an
> embedded web server to utilize the file system? Is a system like Django for
> an app overkill? Or is its embedded development server underkill for a
> single-user browser-based application?
> > --
> > http://mail.python.org/mailman/listinfo/python-list
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From feliphil at gmx.net  Thu May 23 11:41:45 2013
From: feliphil at gmx.net (Wolfgang Keller)
Date: Thu, 23 May 2013 17:41:45 +0200
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
Message-ID: <20130523174145.22a6c46f586b0a1f656d2412@gmx.net>

> But there's another option that is available to every platform and
> (practially) every high level language: the web browser. Make your app
> serve HTTP and do up your UI in HTML5/CSS3 - your facilities are
> pretty extensive. Plus you get networking support for free! Obviously
> this option isn't for everyone, but don't discount it out of hand.

Both the concept and actually implemented examples of so-called "web
applications" prove that they are just plain garbage and hopelessly
unusable for anything remotely resembling actual screenwork.

HTML forms may be at best useful for "web shops", but for actual
screenwork, HTML is not a valid GUI, no matter how much javascript you
add to it.

Sincerely,

Wolfgang


From rosuav at gmail.com  Thu May 23 11:51:32 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 01:51:32 +1000
Subject: Future standard GUI library
In-Reply-To: <20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
Message-ID: <CAPTjJmpacSc0OLgfMynwhnTDWtssAeFxoBZg3rkcW6LV6ARVWA@mail.gmail.com>

On Fri, May 24, 2013 at 1:41 AM, Wolfgang Keller <feliphil at gmx.net> wrote:
>> But there's another option that is available to every platform and
>> (practially) every high level language: the web browser. Make your app
>> serve HTTP and do up your UI in HTML5/CSS3 - your facilities are
>> pretty extensive. Plus you get networking support for free! Obviously
>> this option isn't for everyone, but don't discount it out of hand.
>
> Both the concept and actually implemented examples of so-called "web
> applications" prove that they are just plain garbage and hopelessly
> unusable for anything remotely resembling actual screenwork.
>
> HTML forms may be at best useful for "web shops", but for actual
> screenwork, HTML is not a valid GUI, no matter how much javascript you
> add to it.

All depends on your requirements. For the Yosemite Project, I wanted
the networking aspect, so the web browser UI was a good one. It's been
working beautifully for... what, four or six years now, I think; and
it's just a few pages of Python.

ChrisA


From invalid at invalid.invalid  Thu May 23 16:37:02 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Thu, 23 May 2013 20:37:02 +0000 (UTC)
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
Message-ID: <knlule$5cg$1@reader1.panix.com>

On 2013-05-23, Wolfgang Keller <feliphil at gmx.net> wrote:
>> But there's another option that is available to every platform and
>> (practially) every high level language: the web browser. Make your app
>> serve HTTP and do up your UI in HTML5/CSS3 - your facilities are
>> pretty extensive. Plus you get networking support for free! Obviously
>> this option isn't for everyone, but don't discount it out of hand.
>
> Both the concept and actually implemented examples of so-called "web
> applications" prove that they are just plain garbage and hopelessly
> unusable for anything remotely resembling actual screenwork.

What is "screenwork"?

-- 
Grant Edwards               grant.b.edwards        Yow! Am I elected yet?
                                  at               
                              gmail.com            


From feliphil at gmx.net  Tue May 28 13:28:40 2013
From: feliphil at gmx.net (Wolfgang Keller)
Date: Tue, 28 May 2013 19:28:40 +0200
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<knlule$5cg$1@reader1.panix.com>
Message-ID: <20130528192840.5913f7b6181464616061c015@gmx.net>

> What is "screenwork"?

Actually productive work of significant intensity at a computer screen.

As opposed to leisurely "clicking around" like managers, administrators
or home users (gaming, "webbing",...) do.

Sincerely,

Wolfgang



From invalid at invalid.invalid  Tue May 28 14:25:08 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 18:25:08 +0000 (UTC)
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<knlule$5cg$1@reader1.panix.com>
	<20130528192840.5913f7b6181464616061c015@gmx.net>
Message-ID: <ko2sq4$l93$1@reader1.panix.com>

On 2013-05-28, Wolfgang Keller <feliphil at gmx.net> wrote:

> Actually productive work of significant intensity at a computer screen.

Oh. You mean emacs.

-- 
Grant Edwards               grant.b.edwards        Yow! Will it improve my
                                  at               CASH FLOW?
                              gmail.com            


From dihedral88888 at gmail.com  Tue May 28 19:19:20 2013
From: dihedral88888 at gmail.com (88888 Dihedral)
Date: Tue, 28 May 2013 16:19:20 -0700 (PDT)
Subject: Future standard GUI library
In-Reply-To: <ko2sq4$l93$1@reader1.panix.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<knlule$5cg$1@reader1.panix.com>
	<20130528192840.5913f7b6181464616061c015@gmx.net>
	<ko2sq4$l93$1@reader1.panix.com>
Message-ID: <5d7a9b77-963f-4964-a9f0-83295dc1b30e@googlegroups.com>

Grant Edwards? 2013?5?29????UTC+8??2?25?08????
> On 2013-05-28, Wolfgang Keller <feliphil at gmx.net> wrote:
> 
> 
> 
> > Actually productive work of significant intensity at a computer screen.
> 
> 
> 
> Oh. You mean emacs.
> 
> 
> 
> -- 
> 
> Grant Edwards               grant.b.edwards        Yow! Will it improve my
> 
>                                   at               CASH FLOW?
> 
>                               gmail.com

Check http://www.pyamf.org/index.html for Python +flash
in browser applications. Annyway the virtual server part 
can be obtained from the Adobe system in the cloudy services 
or whatever.

As long as it is scalable  in fees to provide services
to web users  in PCs or mobile phones,
then it might be very profitable than 10 to 15 years ago.


From feliphil at gmx.net  Sun May 26 13:43:10 2013
From: feliphil at gmx.net (Wolfgang Keller)
Date: Sun, 26 May 2013 19:43:10 +0200
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
Message-ID: <20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>

> > Both the concept and actually implemented examples of so-called "web
> > applications" prove that they are just plain garbage and hopelessly
> > unusable for anything remotely resembling actual screenwork.
> >
> > HTML forms may be at best useful for "web shops", but for actual
> > screenwork, HTML is not a valid GUI, no matter how much javascript
> > you add to it.
> 
> All depends on your requirements.

Obivously, if your requirements are to be compliant with latest IT
management fads and to not give a darn for end-user productivity or
even legal requirements for screen workplace ergonomics...

> For the Yosemite Project, I wanted the networking aspect, so the web
> browser UI was a good one.

>From the description this looks like a simble database CRUD
application. Somethign like that is definitely easier to implement and
to deploy and a *lot* more functional with any of the RAD frameworks
available for Python.

And just like HTML never was a valid GUI framework and never will be
one, HTTP will never be a suitable transport layer for a RPC protocol.

Sincerely,

Wolfgang


From roy at panix.com  Sun May 26 14:16:02 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 26 May 2013 14:16:02 -0400
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
Message-ID: <roy-42F0A5.14160226052013@news.panix.com>

In article <20130526194310.9cdb1be80b42c7fdf0ba502f at gmx.net>,
 Wolfgang Keller <feliphil at gmx.net> wrote:

> HTTP will never be a suitable transport layer for a RPC protocol.

What, in particular, is wrong with HTTP for doing RPC?  RPC is pretty 
straight-forward.  Take this method, run it over there, with these 
arguments, and give me back the result.  HTTP handles that just fine, 
with your choice of XML, JSON, or whatever turns you on for the content 
encoding.

There are protocols that are more efficient (mostly binary ones like 
Thrift and Protocol Buffers), but for a lot of things, the simplicity 
and convenience of HTTP is worth than the efficiency hit.  It's really 
nice to be able to slap together HTTP components like load balancers and 
caches by just editing a few config files.


From feliphil at gmx.net  Mon May 27 11:31:23 2013
From: feliphil at gmx.net (Wolfgang Keller)
Date: Mon, 27 May 2013 17:31:23 +0200
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<roy-42F0A5.14160226052013@news.panix.com>
Message-ID: <20130527173123.8ad4fc4af177161c8478be1a@gmx.net>

> HTTP handles that just fine, with your choice of XML, 

And XML is definitely not suitable as a marshalling format for a RPC
protocol.

XML-over-HTTP is a true cerebral flatulance of some hopelessly clueless
moron.

Sincerely,

Wolfgang


From torriem at gmail.com  Mon May 27 13:13:34 2013
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 27 May 2013 11:13:34 -0600
Subject: Future standard GUI library
In-Reply-To: <20130527173123.8ad4fc4af177161c8478be1a@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<roy-42F0A5.14160226052013@news.panix.com>
	<20130527173123.8ad4fc4af177161c8478be1a@gmx.net>
Message-ID: <51A3943E.8070107@gmail.com>

On 05/27/2013 09:31 AM, Wolfgang Keller wrote:
>> HTTP handles that just fine, with your choice of XML, 
> 
> And XML is definitely not suitable as a marshalling format for a RPC
> protocol.
> 
> XML-over-HTTP is a true cerebral flatulance of some hopelessly clueless
> moron.

Hmm.  Well I think there are a lot of very smart developers that are
using xml to marshal rpc and it's working fine.  So either they know
something you don't, or maybe they are just busy making code that
functions and functions pretty well, instead of making inflammatory
statements on USENET.  Sure XML is not very efficient or compact, but it
does handle unicode intrinsically through standard encodings, and a
plethora of parsers makes it a decent choice.  It's like what they say
about the book: "for though it has many omissions and contains much that
is apocryphal, or at least wildly inaccurate, it scores over the older,
more pedestrian work in two important respects.
First, it is slightly cheaper; and second, it has the words Don't Panic
inscribed in large friendly letters on its cover."

I've used LBER-encoded wire protocol before, and it was fine, but hard
to debug on the wire, and didn't haven anything in it to handle unicode
except base64-encoding utf8 byte streams.

That said, all this reminds me of a good saying, "XML is like violence;
if it doesn't solve your problem you're not using enough of it."
Fortunately none of this really matters.  Who cares what is used to
marshall RPC over the wire? As a developer I certainly don't care.  I'll
use whatever is convenient and well supported.  One reason I do like
xmlrpc, though, because it's pretty much available to all web-based back
ends for free (or at little cost) and you don't need to set up a special
server process to handle it, or deal with odd port numbers that might be
blocked, doing ssl yourself, etc.  Having HTTP do the transport frees me
from having to worry about all that, since in the case of a web app I am
already using a web server.


From rosuav at gmail.com  Mon May 27 18:21:25 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 28 May 2013 08:21:25 +1000
Subject: Future standard GUI library
In-Reply-To: <51A3943E.8070107@gmail.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<roy-42F0A5.14160226052013@news.panix.com>
	<20130527173123.8ad4fc4af177161c8478be1a@gmx.net>
	<51A3943E.8070107@gmail.com>
Message-ID: <CAPTjJmpK2Cv+E0FNLP6haZwbAWvYu2JRuumz7Uexmjb7cEqnuQ@mail.gmail.com>

On Tue, May 28, 2013 at 3:13 AM, Michael Torrie <torriem at gmail.com> wrote:
> On 05/27/2013 09:31 AM, Wolfgang Keller wrote:
>>> HTTP handles that just fine, with your choice of XML,
>>
>> And XML is definitely not suitable as a marshalling format for a RPC
>> protocol.
>>
>> XML-over-HTTP is a true cerebral flatulance of some hopelessly clueless
>> moron.
>
> Hmm.  Well I think there are a lot of very smart developers that are
> using xml to marshal rpc and it's working fine.  So either they know
> something you don't, or maybe they are just busy making code that
> functions and functions pretty well, instead of making inflammatory
> statements on USENET.  Sure XML is not very efficient or compact, but it
> does handle unicode intrinsically through standard encodings, and a
> plethora of parsers makes it a decent choice.

I'll use XML when I have to, but if I'm inventing my own protocol,
nope. There are just too many quirks with it. How do you represent an
empty string named Foo?

<Foo></Foo>

or equivalently

<Foo/>

How do you represent an empty list named Foo? The same way. How do you
represent an empty dict/mapping named Foo? Lemme look up my
documentation... ah, the same way. Does this seem right to
you?</JubalEarly>

ChrisA


From roy at panix.com  Mon May 27 19:10:35 2013
From: roy at panix.com (Roy Smith)
Date: Mon, 27 May 2013 19:10:35 -0400
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<roy-42F0A5.14160226052013@news.panix.com>
	<20130527173123.8ad4fc4af177161c8478be1a@gmx.net>
	<51A3943E.8070107@gmail.com>
	<mailman.2265.1369693294.3114.python-list@python.org>
Message-ID: <roy-503DA9.19103527052013@news.panix.com>

In article <mailman.2265.1369693294.3114.python-list at python.org>,
 Chris Angelico <rosuav at gmail.com> wrote:

> I'll use XML when I have to, but if I'm inventing my own protocol,
> nope. There are just too many quirks with it. How do you represent an
> empty string named Foo?
> 
> <Foo></Foo>
> 
> or equivalently
> 
> <Foo/>
> 
> How do you represent an empty list named Foo? The same way. How do you
> represent an empty dict/mapping named Foo? Lemme look up my
> documentation... ah, the same way. Does this seem right to
> you?</JubalEarly>

XML doesn't represent strings, or lists, or dicts.  It represents trees 
of nodes with labels.  If you wish to invent some richer semantic 
meaning to impose on those nodes, that's up to you.

JSON isn't better or worse than XML.  They solve different problems.


From rosuav at gmail.com  Tue May 28 03:11:55 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 28 May 2013 17:11:55 +1000
Subject: Future standard GUI library
In-Reply-To: <roy-503DA9.19103527052013@news.panix.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<roy-42F0A5.14160226052013@news.panix.com>
	<20130527173123.8ad4fc4af177161c8478be1a@gmx.net>
	<51A3943E.8070107@gmail.com>
	<mailman.2265.1369693294.3114.python-list@python.org>
	<roy-503DA9.19103527052013@news.panix.com>
Message-ID: <CAPTjJmofn5uNF7_znCusduKvpa0PRuyJJkwGeBCVEVfOuU6wgw@mail.gmail.com>

On Tue, May 28, 2013 at 9:10 AM, Roy Smith <roy at panix.com> wrote:
> In article <mailman.2265.1369693294.3114.python-list at python.org>,
>  Chris Angelico <rosuav at gmail.com> wrote:
>
>> I'll use XML when I have to, but if I'm inventing my own protocol,
>> nope. There are just too many quirks with it. How do you represent an
>> empty string named Foo?
>>
>> <Foo></Foo>
>>
>> or equivalently
>>
>> <Foo/>
>>
>> How do you represent an empty list named Foo? The same way. How do you
>> represent an empty dict/mapping named Foo? Lemme look up my
>> documentation... ah, the same way. Does this seem right to
>> you?</JubalEarly>
>
> XML doesn't represent strings, or lists, or dicts.  It represents trees
> of nodes with labels.  If you wish to invent some richer semantic
> meaning to impose on those nodes, that's up to you.

Sure it doesn't, but it's very often used that way. So I guess what
I'm really saying is that XML is wrong for 90% of the places it's
used.

ChrisA


From dihedral88888 at gmail.com  Tue May 28 05:40:40 2013
From: dihedral88888 at gmail.com (88888 Dihedral)
Date: Tue, 28 May 2013 02:40:40 -0700 (PDT)
Subject: Future standard GUI library
In-Reply-To: <mailman.2284.1369725123.3114.python-list@python.org>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<roy-42F0A5.14160226052013@news.panix.com>
	<20130527173123.8ad4fc4af177161c8478be1a@gmx.net>
	<51A3943E.8070107@gmail.com>
	<mailman.2265.1369693294.3114.python-list@python.org>
	<roy-503DA9.19103527052013@news.panix.com>
	<mailman.2284.1369725123.3114.python-list@python.org>
Message-ID: <077a358c-81b8-4529-8232-40cbaa331012@googlegroups.com>

Chris Angelico? 2013?5?28????UTC+8??3?11?55????
> On Tue, May 28, 2013 at 9:10 AM, Roy Smith <roy at panix.com> wrote:
> 
> > In article <mailman.2265.1369693294.3114.python-list at python.org>,
> 
> >  Chris Angelico <rosuav at gmail.com> wrote:
> 
> >
> 
> >> I'll use XML when I have to, but if I'm inventing my own protocol,
> 
> >> nope. There are just too many quirks with it. How do you represent an
> 
> >> empty string named Foo?
> 
> >>
> 
> >> <Foo></Foo>
> 
> >>
> 
> >> or equivalently
> 
> >>
> 
> >> <Foo/>
> 
> >>
> 
> >> How do you represent an empty list named Foo? The same way. How do you
> 
> >> represent an empty dict/mapping named Foo? Lemme look up my
> 
> >> documentation... ah, the same way. Does this seem right to
> 
> >> you?</JubalEarly>
> 
> >
> 
> > XML doesn't represent strings, or lists, or dicts.  It represents trees
> 
> > of nodes with labels.  If you wish to invent some richer semantic
> 
> > meaning to impose on those nodes, that's up to you.
> 
> 
> 
> Sure it doesn't, but it's very often used that way. So I guess what
> 
> I'm really saying is that XML is wrong for 90% of the places it's
> 
> used.
> 
> 
> 
> ChrisA

Please check the annual sales in Ebay or similar sites  and the 
advertizement fees collected by Google and Yahoo.







From denismfmcmahon at gmail.com  Mon May 27 21:01:47 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Tue, 28 May 2013 01:01:47 +0000 (UTC)
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<roy-42F0A5.14160226052013@news.panix.com>
	<20130527173123.8ad4fc4af177161c8478be1a@gmx.net>
	<51A3943E.8070107@gmail.com>
	<mailman.2265.1369693294.3114.python-list@python.org>
Message-ID: <ko0vlr$a5h$4@dont-email.me>

On Tue, 28 May 2013 08:21:25 +1000, Chris Angelico wrote:

> I'll use XML when I have to, but if I'm inventing my own protocol,
> nope. There are just too many quirks with it. How do you represent an
> empty string named Foo?

> <Foo></Foo>

> or equivalently

> <Foo/>

> How do you represent an empty list named Foo? The same way. How do you
> represent an empty dict/mapping named Foo? Lemme look up my
> documentation... ah, the same way. Does this seem right to
> you?</JubalEarly>

<Foo type="list" />
<Foo type="mapping" />
<Foo type="string" />

-- 
Denis McMahon, denismfmcmahon at gmail.com


From carlosnepomuceno at outlook.com  Sun May 26 14:32:56 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 21:32:56 +0300
Subject: Future standard GUI library
In-Reply-To: <20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>,
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>,
	<mailman.1967.1369232658.3114.python-list@python.org>,
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>,
	<mailman.2020.1369324735.3114.python-list@python.org>,
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
Message-ID: <BLU176-W1338080E50793BF326FEED7950@phx.gbl>

----------------------------------------
> From: feliphil at gmx.net
> Subject: Re: Future standard GUI library
> Date: Sun, 26 May 2013 19:43:10 +0200
> To: python-list at python.org
[...]
> one, HTTP will never be a suitable transport layer for a RPC protocol.
>
> Sincerely,
>
> Wolfgang


Please give me an example of a "suitable transport layer for a RPC protocol". 		 	   		  

From rosuav at gmail.com  Sun May 26 14:56:19 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 04:56:19 +1000
Subject: Future standard GUI library
In-Reply-To: <20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
Message-ID: <CAPTjJmrxk8Y9FqpZKkhYpMSYb17abd1M5egO89-VMbDR838X=A@mail.gmail.com>

On Mon, May 27, 2013 at 3:43 AM, Wolfgang Keller <feliphil at gmx.net> wrote:
>> For the Yosemite Project, I wanted the networking aspect, so the web
>> browser UI was a good one.
>
> From the description this looks like a simble database CRUD
> application. Somethign like that is definitely easier to implement and
> to deploy and a *lot* more functional with any of the RAD frameworks
> available for Python.
>
> And just like HTML never was a valid GUI framework and never will be
> one, HTTP will never be a suitable transport layer for a RPC protocol.

No, it's basically a modified version of a file browser; you get a
directory listing, you can browse subdirectories, and selecting a file
causes an action to happen on the server. You also have some "action
buttons" that provide a measure of control: click a button and
something is done (eg a key is pressed, or a 'killall' command is
fired). The browser works just fine.

ChrisA


From torriem at gmail.com  Sun May 26 15:41:44 2013
From: torriem at gmail.com (Michael Torrie)
Date: Sun, 26 May 2013 13:41:44 -0600
Subject: Future standard GUI library
In-Reply-To: <20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
Message-ID: <51A26578.5040402@gmail.com>

On 05/26/2013 11:43 AM, Wolfgang Keller wrote:
> And just like HTML never was a valid GUI framework and never will be
> one, HTTP will never be a suitable transport layer for a RPC protocol.

On good thing web development has brought us is the knowledge that
modularization and layers are a brilliant idea.  Your back end exposes
services and business logic, and your front end can be in HTMLv5 and
Javascript, or QtQuick, PyGTK, or Visual Studio.  If you do need a
native interface, it's a heck of a lot easier to rewrite just the
frontend then the entire stack.  Who cares how the RPC is done; that's
an implementation detail.  HTTP does happen to work well though.  Why do
you say it is not suitable?

> From the description this looks like a simble database CRUD
> application. Somethign like that is definitely easier to implement and
> to deploy and a *lot* more functional with any of the RAD frameworks
> available for Python.

Chuckle.  Simple CRUD, eh.  Almost all apps involve database CRUD
interactions.  And often in highly complex ways using business logic.

Maybe it would have been faster to develop, but ultimately less useful
and require more development time in the long run.  suppose I now want
the app natively on my phone (because that's all the rage).  It's an
iPhone.  Oh.  Apple doesn't support Python.  Okay, rewrite the works,
including business logic, in Objective C.  Now I want it on my android
phone.  Oops rewrite the stack again in Java.

Since his application by nature is network oriented (client/server I
presume since he mentions multiple users), sticking it on a web server
and having the front end be separate (be it HTML or not) gives him the
flexibility to rapidly build native "screenable" UIs for his app on any
platform he chooses, something your philosophy does not allow for.


From ian at feete.org  Sun May 26 17:02:02 2013
From: ian at feete.org (Ian Foote)
Date: Sun, 26 May 2013 22:02:02 +0100
Subject: Future standard GUI library
In-Reply-To: <51A26578.5040402@gmail.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<51A26578.5040402@gmail.com>
Message-ID: <51A2784A.2060101@feete.org>

On 26/05/13 20:41, Michael Torrie wrote:
> On 05/26/2013 11:43 AM, Wolfgang Keller wrote:
<snip>
>
> Maybe it would have been faster to develop, but ultimately less useful
> and require more development time in the long run.  suppose I now want
> the app natively on my phone (because that's all the rage).  It's an
> iPhone.  Oh.  Apple doesn't support Python.  Okay, rewrite the works,
> including business logic, in Objective C.  Now I want it on my android
> phone.  Oops rewrite the stack again in Java.
>
Kivy (http://kivy.org) is a python library that can be used to write 
python apps for Linux, Windows, MaxOSX, Android and IOS.

Regards,
Ian F


From rosuav at gmail.com  Sun May 26 18:09:38 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 08:09:38 +1000
Subject: Future standard GUI library
In-Reply-To: <51A26578.5040402@gmail.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<51A26578.5040402@gmail.com>
Message-ID: <CAPTjJmocsAOn5XFzT5aAaLy=gXyy7iD7_OLzysQ1yDjQmJtKGw@mail.gmail.com>

On Mon, May 27, 2013 at 5:41 AM, Michael Torrie <torriem at gmail.com> wrote:
> Chuckle.  Simple CRUD, eh.  Almost all apps involve database CRUD
> interactions.  And often in highly complex ways using business logic.

Right. Sturgeon's Law of Applications.

ChrisA


From roy at panix.com  Sun May 26 15:45:39 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 26 May 2013 15:45:39 -0400
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2193.1369597318.3114.python-list@python.org>
Message-ID: <roy-C2C59A.15453926052013@news.panix.com>

In article <mailman.2193.1369597318.3114.python-list at python.org>,
 Michael Torrie <torriem at gmail.com> wrote:

> On good thing web development has brought us is the knowledge that
> modularization and layers are a brilliant idea.

Modularization and layers were a brilliant idea long before the web came 
around.


From torriem at gmail.com  Sun May 26 17:13:09 2013
From: torriem at gmail.com (Michael Torrie)
Date: Sun, 26 May 2013 15:13:09 -0600
Subject: Future standard GUI library
In-Reply-To: <roy-C2C59A.15453926052013@news.panix.com>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2193.1369597318.3114.python-list@python.org>
	<roy-C2C59A.15453926052013@news.panix.com>
Message-ID: <51A27AE5.6050605@gmail.com>

On 05/26/2013 01:45 PM, Roy Smith wrote:
> In article <mailman.2193.1369597318.3114.python-list at python.org>,
>  Michael Torrie <torriem at gmail.com> wrote:
> 
>> On good thing web development has brought us is the knowledge that
>> modularization and layers are a brilliant idea.
> 
> Modularization and layers were a brilliant idea long before the web came 
> around.

True.  Though it seems like it fell out of fashion for a long time.  I
went to school before the advent of web development and though we talked
about modularization and coupling in software engineering, really it was
all rather monolithic.  Web development changed our focus back to where
it should have been all along.


From invalid at invalid.invalid  Tue May 28 11:40:25 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 15:40:25 +0000 (UTC)
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2193.1369597318.3114.python-list@python.org>
	<roy-C2C59A.15453926052013@news.panix.com>
Message-ID: <ko2j59$9oh$2@reader1.panix.com>

On 2013-05-26, Roy Smith <roy at panix.com> wrote:
>  Michael Torrie <torriem at gmail.com> wrote:
>
>> On good thing web development has brought us is the knowledge that
>> modularization and layers are a brilliant idea.
>
> Modularization and layers were a brilliant idea long before the web came 
> around.

Once again USENET proves to be an unsuitable RPC protocol for
implementing irony.  :)

[OTOH, perhaps Micheal wasn't being ironic...]

-- 
Grant Edwards               grant.b.edwards        Yow! Am I having fun yet?
                                  at               
                              gmail.com            


From feliphil at gmx.net  Mon May 27 11:22:50 2013
From: feliphil at gmx.net (Wolfgang Keller)
Date: Mon, 27 May 2013 17:22:50 +0200
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2193.1369597318.3114.python-list@python.org>
Message-ID: <20130527172250.a8b0ce44f29398d63a4ec650@gmx.net>

> Your back end exposes services and business logic, and your front end
> can be in HTMLv5 and Javascript, or QtQuick, PyGTK, or Visual
> Studio.  If you do need a native interface, it's a heck of a lot
> easier to rewrite just the frontend then the entire stack.

Any decent database CRUD framework will allow to implement the
application model as "behaviour complete" domain objects, with a
persistence layer totally independent from the GUI layer. In many
Python RAD frameworks, this is done using SQLalchemy.

> Who cares how the RPC is done;

As an end-user I do care for how much an application makes we watch the
cursor animation.

> that's an implementation detail.  HTTP does happen to work well
> though.  Why do you say it is not suitable?

Because from personal experience I know too well that it does definitely
not "work well though". 

> suppose I now want the app natively on my phone (because that's all
> the rage).  It's an iPhone.  Oh.  Apple doesn't support Python.
> Okay, rewrite the works, including business logic, in Objective C.
> Now I want it on my android phone. 

Those are gadgets, not work tools.

Sincerely,

Wolfgang


From torriem at gmail.com  Mon May 27 13:16:21 2013
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 27 May 2013 11:16:21 -0600
Subject: Future standard GUI library
In-Reply-To: <20130527172250.a8b0ce44f29398d63a4ec650@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2193.1369597318.3114.python-list@python.org>
	<20130527172250.a8b0ce44f29398d63a4ec650@gmx.net>
Message-ID: <51A394E5.1010409@gmail.com>

On 05/27/2013 09:22 AM, Wolfgang Keller wrote:
>> suppose I now want the app natively on my phone (because that's all
>> the rage).  It's an iPhone.  Oh.  Apple doesn't support Python.
>> Okay, rewrite the works, including business logic, in Objective C.
>> Now I want it on my android phone. 
> 
> Those are gadgets, not work tools.

As a professional programmer I'm afraid you're going to soon find
yourself out of work if you really see things that way.  I honestly used
to feel that way about graphical user interfaces.


From feliphil at gmx.net  Thu May 30 12:40:45 2013
From: feliphil at gmx.net (Wolfgang Keller)
Date: Thu, 30 May 2013 18:40:45 +0200
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2193.1369597318.3114.python-list@python.org>
	<20130527172250.a8b0ce44f29398d63a4ec650@gmx.net>
	<mailman.2258.1369674988.3114.python-list@python.org>
Message-ID: <20130530184045.6d15530be70e18d96e5654ad@gmx.net>

> >> suppose I now want the app natively on my phone (because that's all
> >> the rage).  It's an iPhone.  Oh.  Apple doesn't support Python.
> >> Okay, rewrite the works, including business logic, in Objective C.
> >> Now I want it on my android phone. 
> > 
> > Those are gadgets, not work tools.
> 
> As a professional programmer I'm afraid you're going to soon find
> yourself out of work if you really see things that way.

As a "domain expert", I come from the end-user side of "enterprise
applications" and again; those are not tools for screenworkers to get
actual work done, but consumer crap for fad-driven gadget-addicted kids
(regardless of nominal age).

> I honestly used to feel that way about graphical user interfaces.

A GUI that can not be used without taking the ten fingers off the
keyboard is indeed entirely unusable for any half-proficient
screenworker. And anyone doing actual productive screenwork every day
for more than just a few months will inevitably (have to) get proficient
(unless completely braindead).

Sincerely,

Wolfgang


From rosuav at gmail.com  Thu May 30 12:53:14 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 02:53:14 +1000
Subject: Future standard GUI library
In-Reply-To: <20130530184045.6d15530be70e18d96e5654ad@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2193.1369597318.3114.python-list@python.org>
	<20130527172250.a8b0ce44f29398d63a4ec650@gmx.net>
	<mailman.2258.1369674988.3114.python-list@python.org>
	<20130530184045.6d15530be70e18d96e5654ad@gmx.net>
Message-ID: <CAPTjJmqnuRGTaZ-Eb0roAyrBuUXQwopAJ6SWCj3DfDJpaBPq-w@mail.gmail.com>

On Fri, May 31, 2013 at 2:40 AM, Wolfgang Keller <feliphil at gmx.net> wrote:
> A GUI that can not be used without taking the ten fingers off the
> keyboard is indeed entirely unusable for any half-proficient
> screenworker. And anyone doing actual productive screenwork every day
> for more than just a few months will inevitably (have to) get proficient
> (unless completely braindead).

My ten fingers stay on my keyboard, which looks somewhat thus:

http://www.xbitlabs.com/images/mobile/lenovo-thinkpad-t61/keyboard.jpg

See the red dot in the middle? Mouse. See the keys all around it? My
hands are all over that. I can casually mouse and keyboard at the same
time. Doesn't bother me.

THIS is a professional programmer's workspace. :)

ChrisA


From feliphil at gmx.net  Tue May 28 13:26:55 2013
From: feliphil at gmx.net (Wolfgang Keller)
Date: Tue, 28 May 2013 19:26:55 +0200
Subject: Future standard GUI library
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2188.1369593244.3114.python-list@python.org>
Message-ID: <20130528192655.08861babbd86e890634e6d90@gmx.net>

> Please give me an example of a "suitable transport layer for a RPC
> protocol". 		 	   		  

I won't give you an example, but just some very basic criteria:

- It must be very efficient for very small "datagrams"
- It must provide connections
- For asynchronous programming it must provide for callbacks

No RPC-over-HTTP protocol that I know of does this.

Besides, no one needs RPC just to logically separate GUI and
application layer. And between application logic and database, you use
the native database API for the RDBMS in question, of course.

The whole idea to centralise application logic (and even the GUI with
"web applications") is backwards, it dates from the 70s/early 80s when
desktop computers weren't able to run application logic. Today, to make
an application responsive (minimise latencies and maximise throughput),
it's just obvious to *de*-centralise as much as possible. In fact,
if Postgres-R was available for production, you could even distribute
the persistence and run an entirely "serverless" application.

Sincerely,

Wolfgang


From torriem at gmail.com  Tue May 28 14:16:20 2013
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 28 May 2013 12:16:20 -0600
Subject: Future standard GUI library
In-Reply-To: <20130528192655.08861babbd86e890634e6d90@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2188.1369593244.3114.python-list@python.org>
	<20130528192655.08861babbd86e890634e6d90@gmx.net>
Message-ID: <51A4F474.7050908@gmail.com>

On 05/28/2013 11:26 AM, Wolfgang Keller wrote:
>> Please give me an example of a "suitable transport layer for a RPC
>> protocol". 		 	   		  
> 
> I won't give you an example, but just some very basic criteria:
> 
> - It must be very efficient for very small "datagrams"

I won't argue for XML here, but sometimes space efficiency is simply a
premature optimization.

> - It must provide connections

How would you do this?  Connections can and do get dropped regularly.
To rebuild connections you need another layer to track them.

> - For asynchronous programming it must provide for callbacks

What do you mean by this?  A transport layer has nothing to do with
callbacks.  All a client can do is make the call, and wait for the
answer.  The client library can make it look asynchronous of course.
And I suppose one could implement an RPC system using UDP where answer
packets are dispatched as they come in.


From carlosnepomuceno at outlook.com  Tue May 28 17:17:13 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 29 May 2013 00:17:13 +0300
Subject: Future standard GUI library
In-Reply-To: <20130528192655.08861babbd86e890634e6d90@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>,
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>,
	<mailman.1967.1369232658.3114.python-list@python.org>,
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>,
	<mailman.2020.1369324735.3114.python-list@python.org>,
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>,
	<mailman.2188.1369593244.3114.python-list@python.org>,
	<20130528192655.08861babbd86e890634e6d90@gmx.net>
Message-ID: <BLU176-W43BE45C0C4C14A4587F65D7970@phx.gbl>

----------------------------------------
> From: feliphil at gmx.net
> Subject: Re: Future standard GUI library
> Date: Tue, 28 May 2013 19:26:55 +0200
> To: python-list at python.org
>
>> Please give me an example of a "suitable transport layer for a RPC
>> protocol".
>
> I won't give you an example, but just some very basic criteria:
>
> - It must be very efficient for very small "datagrams"

Interoperability is much more expensive than efficiency. That's why you won't get the most optimized protocol for speed or size.

> - It must provide connections

What do you mean?

> - For asynchronous programming it must provide for callbacks
> No RPC-over-HTTP protocol that I know of does this.

XHR implements asynchronous callbacks over HTTP.

> Besides, no one needs RPC just to logically separate GUI and
> application layer. And between application logic and database, you use
> the native database API for the RDBMS in question, of course.
>
> The whole idea to centralise application logic (and even the GUI with
> "web applications") is backwards, it dates from the 70s/early 80s when
> desktop computers weren't able to run application logic. Today, to make
> an application responsive (minimise latencies and maximise throughput),
> it's just obvious to *de*-centralise as much as possible. In fact,
> if Postgres-R was available for production, you could even distribute
> the persistence and run an entirely "serverless" application.

"web applications" is so nowadays! All of my recent software development projects (last 10 years) focus on business processes integration.
In all of them the BLL (Business Logic Layer), or "application logic", is run on server side (as a controller in MVC) due to security and performance reasons.
None of my clients want their business rules and internal workflows exposed, so the old ways of the 70/80's ain't gonna change.

> Sincerely,
>
> Wolfgang
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rosuav at gmail.com  Wed May 29 03:20:04 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 29 May 2013 17:20:04 +1000
Subject: Future standard GUI library
In-Reply-To: <20130528192655.08861babbd86e890634e6d90@gmx.net>
References: <mailman.1803.1368885785.3114.python-list@python.org>
	<20130522154233.fe5263cb231c375fc60c7c9b@gmx.net>
	<mailman.1967.1369232658.3114.python-list@python.org>
	<20130523174145.22a6c46f586b0a1f656d2412@gmx.net>
	<mailman.2020.1369324735.3114.python-list@python.org>
	<20130526194310.9cdb1be80b42c7fdf0ba502f@gmx.net>
	<mailman.2188.1369593244.3114.python-list@python.org>
	<20130528192655.08861babbd86e890634e6d90@gmx.net>
Message-ID: <CAPTjJmq8g9cCSTXsZc+-qxwCzvFm3chj1YsNXvJSg6LjYB+YLw@mail.gmail.com>

On Wed, May 29, 2013 at 3:26 AM, Wolfgang Keller <feliphil at gmx.net> wrote:
> I won't give you an example, but just some very basic criteria:
>
> - It must be very efficient for very small "datagrams"
> - It must provide connections
> - For asynchronous programming it must provide for callbacks

In other words, a TELNET connection. I absolutely concur.

I've made extensive use of that family of protocols; between MUDs
(three active connections right at this moment), mail (SMTP and POP
both), actual command execution (though that's usually encrypted via
SSH), and *seven* separate protocols that I devised for work, I pretty
much *always* am working with a system that parses text into lines and
(usually) lines into commands with arguments. It's a broad concept
that can be applied to *everything*. I'm firmly of the opinion that
Magic: The Gathering could be played over a MUD connection.

ChrisA


From tjreedy at udel.edu  Sat May 18 16:53:55 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sat, 18 May 2013 16:53:55 -0400
Subject: Future standard GUI library
In-Reply-To: <CAPbpa4QQf1NZd-0-GDH=wjBMApBmh5=FXfWxFp28dngbXrPWWQ@mail.gmail.com>
References: <CAPbpa4QQf1NZd-0-GDH=wjBMApBmh5=FXfWxFp28dngbXrPWWQ@mail.gmail.com>
Message-ID: <kn8poq$67a$1@ger.gmane.org>

On 5/18/2013 10:03 AM, Beinan Li wrote:
> Not sure if this is the right place to talk about this.

It is.

> Even less sure if I can
> move this discussion to tkinter list,

The idea of replacing tkinter is not about improving tkinter ;-).

> Do you think tkinter is going to be the standard python built-in gui
> solution as long as python exists?

AT the moment, there is nothing really comparable that is a realistic 
candidate to replace tkinter. Tkinter is a tcl-based c gui library. wx 
and qt4 are gui application frameworks that include a gui library -- and 
much more that duplicate part of Python's stdlib. They, and consequently 
their Python wrappers, are too big. That is quite aside from the fact 
that the authors of the wrappers have good reason to not donate their 
code, but stay independent.

PyGui was designed as a gui library comparable to tkinter and a possible 
replacement. But according to the web page, it is still not completely 
ready for py 3 (the last update was July 2011).
http://www.cosc.canterbury.ac.nz/greg.ewing/python_gui/

I think a tkinter replacement should be written for at least 3.4+, so it 
can use the new 3.3 unicode implementation and use or at least integrate 
with the new 3.4 event loop that will be part of the planned new async 
library.

One test for any new gui library is whether idle can be rewritten in it. 
It heavily uses the tag features of the tk text widget.

TJR





From vito.detullio at gmail.com  Mon May 20 01:04:37 2013
From: vito.detullio at gmail.com (Vito De Tullio)
Date: Mon, 20 May 2013 07:04:37 +0200
Subject: Future standard GUI library
References: <CAPbpa4QQf1NZd-0-GDH=wjBMApBmh5=FXfWxFp28dngbXrPWWQ@mail.gmail.com>
	<kn8poq$67a$1@ger.gmane.org>
Message-ID: <kncat4$hpa$1@ger.gmane.org>

Terry Jan Reedy wrote:

>> Do you think tkinter is going to be the standard python built-in gui
>> solution as long as python exists?
> 
> AT the moment, there is nothing really comparable that is a realistic
> candidate to replace tkinter.

FLTK? (http://www.fltk.org/index.php)

-- 
ZeD



From tjreedy at udel.edu  Mon May 20 03:00:36 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Mon, 20 May 2013 03:00:36 -0400
Subject: Future standard GUI library
In-Reply-To: <kncat4$hpa$1@ger.gmane.org>
References: <CAPbpa4QQf1NZd-0-GDH=wjBMApBmh5=FXfWxFp28dngbXrPWWQ@mail.gmail.com>
	<kn8poq$67a$1@ger.gmane.org> <kncat4$hpa$1@ger.gmane.org>
Message-ID: <knchmf$hd7$1@ger.gmane.org>

On 5/20/2013 1:04 AM, Vito De Tullio wrote:
> Terry Jan Reedy wrote:
>
>>> Do you think tkinter is going to be the standard python built-in gui
>>> solution as long as python exists?
>>
>> AT the moment, there is nothing really comparable that is a realistic
>> candidate to replace tkinter.
>
> FLTK? (http://www.fltk.org/index.php)

tkinter is the Python wrapper of the tk library, just as wxpython is the 
python wrapper of the wx library. I do not see a py-fltk wrapper.




From robert.kern at gmail.com  Mon May 20 05:32:28 2013
From: robert.kern at gmail.com (Robert Kern)
Date: Mon, 20 May 2013 10:32:28 +0100
Subject: Future standard GUI library
In-Reply-To: <knchmf$hd7$1@ger.gmane.org>
References: <CAPbpa4QQf1NZd-0-GDH=wjBMApBmh5=FXfWxFp28dngbXrPWWQ@mail.gmail.com>
	<kn8poq$67a$1@ger.gmane.org> <kncat4$hpa$1@ger.gmane.org>
	<knchmf$hd7$1@ger.gmane.org>
Message-ID: <kncqj6$6qm$1@ger.gmane.org>

On 2013-05-20 08:00, Terry Jan Reedy wrote:
> On 5/20/2013 1:04 AM, Vito De Tullio wrote:
>> Terry Jan Reedy wrote:
>>
>>>> Do you think tkinter is going to be the standard python built-in gui
>>>> solution as long as python exists?
>>>
>>> AT the moment, there is nothing really comparable that is a realistic
>>> candidate to replace tkinter.
>>
>> FLTK? (http://www.fltk.org/index.php)
>
> tkinter is the Python wrapper of the tk library, just as wxpython is the python
> wrapper of the wx library. I do not see a py-fltk wrapper.

It exists, but it's really old.

http://pyfltk.sourceforge.net/

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco



From feliphil at gmx.net  Wed May 22 09:40:44 2013
From: feliphil at gmx.net (Wolfgang Keller)
Date: Wed, 22 May 2013 15:40:44 +0200
Subject: Future standard GUI library
References: <CAPbpa4QQf1NZd-0-GDH=wjBMApBmh5=FXfWxFp28dngbXrPWWQ@mail.gmail.com>
	<kn8poq$67a$1@ger.gmane.org> <kncat4$hpa$1@ger.gmane.org>
	<knchmf$hd7$1@ger.gmane.org>
	<mailman.1880.1369042358.3114.python-list@python.org>
Message-ID: <20130522154044.2cf203bf3c9f1dbf13dbafbb@gmx.net>

> >>>> Do you think tkinter is going to be the standard python built-in
> >>>> gui solution as long as python exists?
> >>>
> >>> AT the moment, there is nothing really comparable that is a
> >>> realistic candidate to replace tkinter.
> >>
> >> FLTK? (http://www.fltk.org/index.php)
> >
> > tkinter is the Python wrapper of the tk library, just as wxpython
> > is the python wrapper of the wx library. I do not see a py-fltk
> > wrapper.
> 
> It exists, but it's really old.
> 
> http://pyfltk.sourceforge.net/

And it's imho definitely not "native" (in terms of "look and feel") on
*any* operating system, not even on Linux.

In fact it's SGI's Irix Forms re-implemented, afaik.

Sincerely,

Wolfgang


From invalid at invalid.invalid  Mon May 20 16:18:21 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Mon, 20 May 2013 20:18:21 +0000 (UTC)
Subject: Future standard GUI library
References: <CAPbpa4QQf1NZd-0-GDH=wjBMApBmh5=FXfWxFp28dngbXrPWWQ@mail.gmail.com>
	<kn8poq$67a$1@ger.gmane.org> <kncat4$hpa$1@ger.gmane.org>
	<mailman.1862.1369033253.3114.python-list@python.org>
Message-ID: <kne0ed$bvl$1@reader1.panix.com>

On 2013-05-20, Terry Jan Reedy <tjreedy at udel.edu> wrote:
> On 5/20/2013 1:04 AM, Vito De Tullio wrote:
>> Terry Jan Reedy wrote:
>>
>>>> Do you think tkinter is going to be the standard python built-in gui
>>>> solution as long as python exists?
>>>
>>> AT the moment, there is nothing really comparable that is a realistic
>>> candidate to replace tkinter.
>>
>> FLTK? (http://www.fltk.org/index.php)
>
> tkinter is the Python wrapper of the tk library, just as wxpython is
> the python wrapper of the wx library. I do not see a py-fltk wrapper.

http://pyfltk.sourceforge.net/

-- 
Grant Edwards               grant.b.edwards        Yow! Is it 1974?  What's
                                  at               for SUPPER?  Can I spend
                              gmail.com            my COLLEGE FUND in one
                                                   wild afternoon??


From kw at codebykevin.com  Mon May 20 06:32:13 2013
From: kw at codebykevin.com (Kevin Walzer)
Date: Mon, 20 May 2013 06:32:13 -0400
Subject: Future standard GUI library
In-Reply-To: <mailman.1858.1369026294.3114.python-list@python.org>
References: <CAPbpa4QQf1NZd-0-GDH=wjBMApBmh5=FXfWxFp28dngbXrPWWQ@mail.gmail.com>
	<kn8poq$67a$1@ger.gmane.org>
	<mailman.1858.1369026294.3114.python-list@python.org>
Message-ID: <knctrt$g24$1@dont-email.me>

On 5/20/13 1:04 AM, Vito De Tullio wrote:
> FLTK? (http://www.fltk.org/index.php)

FLTK is even uglier than non-themed Tkinter: non-native on every 
platform. Tkinter wraps native widgets on MacOS and WIndows, but FLTK 
draws its own widgets everywhere.

-- 
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
http://www.wtmobilesoftware.com


From li.beinan at gmail.com  Sat May 18 17:30:44 2013
From: li.beinan at gmail.com (Beinan Li)
Date: Sat, 18 May 2013 17:30:44 -0400
Subject: Future standard GUI library
Message-ID: <CAPbpa4TOV5zZ7GTKYg0Kg=JdCoyBxLZE00LWaYMOT10WxQ=WKw@mail.gmail.com>

Thanks for the clarification, Kevin.
It's nice to have a tk dev standing out :-)
This more or less convinced me about the trend.

I also agree that it would be probably a simpler and more maintainable way
to write my own tk(inter) code than using any existing 3rd-party designers.


Beinan

On Sat, May 18, 2013 at 1:40 PM, <python-list-request at python.org> wrote:

>
>
> ---------- Forwarded message ----------
> From: Kevin Walzer <kw at codebykevin.com>
> To: python-list at python.org
> Cc:
> Date: Sat, 18 May 2013 11:32:04 -0400
> Subject: Re: Future standard GUI library
> Hello,
>
> On 5/18/13 10:03 AM, Beinan Li wrote:
>
>  I know this may sound a silly question because no one can see the
>> future. But ...
>> Do you think tkinter is going to be the standard python built-in gui
>> solution as long as python exists?
>>
>
> I don't see any significant clamoring among the Python core developers to
> make a change.
>
>
>> I couldn't help but wonder if wx or PySide receives better py2 and py3
>> support, or anything else that prevent
>> them from getting into the standard python distributions, whether or not
>> this scene could start to shift ...
>>
>
> I am not going to engage in the old UI toolkit flame ware; I will limit
> myself to factual observations and a few opinions about Tkinter without
> placing it against other toolkits.
>
> Python has the PEP process for suggesting changes to the core language and
> libraries. Changing the default UI toolkit would require someone to submit
> a proposal, get it approved, provide the implementation, and commit to
> maintaining the implementation over the long term. You propose it, you own
> it.
>
> Thus far no one has done this. I would think the only person who would be
> in a position to propose wxPython would be Robin Dunn since he is the
> primary copyright holder, and to my knowledge he has never done so. As for
> Pyside, it was not part of the transition of Qt from Nokia to Digia, and so
> it appears to be orphaned. PyQt might be an alternative, but I don't think
> Phil Thompson would ever submit it, as it would likely affect his
> livelihood.
>
> Given these facts, it's safe to say that Tkinter will remain the default
> GUI toolkit in the stdlib for some years to come.
>
>
>> I believe this "which one of tkinter, wx, qt, is the best gui toolkit
>> for python" flame war has been going on
>> for ages. I love the fact that python ships a built-in gui solution
>> which makes shipping a pure-python desktop
>> application a viable choice. But tkinter does not appear to be the most
>> time-saving way to write a gui app.
>> The layout designer support, for one, is next to zero. I tried many
>> 3rd-party designers
>> and loved PAGE (http://page.sourceforge.net) for a few minutes, then
>> came the author's comment:
>>
>
> PAGE strikes me as an odd choice for a Python developer to develop a Tk
> UI. It's a descendent of the old Visual Tcl tool, and is run from Tcl and
> not Python. VTcl was always famous for producing a huge pot of spaghetti UI
> code that couldn't be easily modified outside the tool. I have also tried
> many Tk UI tools including VTcl, SpecTcl, and the orphaned tool from
> ActiveState, and have concluded that writing my own code is both simpler
> and faster. As always, your mileage may vary.
>
>
>> "For release 4.0, I spent about two months working with the ?Theme? part
>> of Ttk and have had only partial success. I now believe that the ?Theme?
>> part of Ttk is really a very poor piece of software at all levels -
>> concept, implementation, and especially documentation. My guess is if it
>> had been well documented it would have been recognized by even the
>> author as junk. I find it hard to believe that the people who control
>> Tcl/Tk allowed it in the code base. I continue to support ttk because of
>> the paned window, notebook and treeview widgets."
>>
>
> The implementation of the ttk widgets is quite complex--that, in turn,
> makes their documentation complex, and the complexity is a drawback. It's
> hard to customize the ttk themes, especially compared to customizing
> standard Tk widgets. I'm one of the core Tk developers, and I don't fully
> understand the themed widgets' internals or how to customize them. But it's
> not fair to say that they are "junk." The author of PAGE may think so, but
> many would disagree. I think the widgets work quite well, especially if
> used in their default mode. It's difficult to overstate the improvement in
> the look and feel of my Tk apps on the Mac when I switched to using the
> themed widgets.
>
>
>> And ttk seems to be a major attraction that keeps people coming back to
>> tk for the looks. This worries me very much
>> about whether I should start a gui app using python. Because if ttk is
>> not a "mature" technology, I'd avoid premature adoption.
>> If ttk is out of the question, tkinter will be too. I'd then be forced
>> to use a 3rd-party solution like wx or qt, which I really don't want to
>> see.
>>
>
> ttk is a mature technology. The initial specification, code, and docs were
> developed by Joe English nearly a decade ago (see
> http://tktable.sourceforge.**net/tile/tile-tcl2004.pdf<http://tktable.sourceforge.net/tile/tile-tcl2004.pdf>),
> and they had been accepted into Tcl/Tk's core in version 8.5 (released in
> 2007). The earliest work on integrating these widgets into Python began in
> 2008, and they were formally released in 2010.  I would say that ttk is
> mature, stable, and unlikely to undergo radical change in the future.
>
> Guilherme Polo has done superb work in integrating the themed widgets into
> Python--it's the most significant UI advance in Python's stdlib in years.
> You are quite safe in developing against this API, unless your taste simply
> does not run to using the ttk widgets.
>
> Hope this helps,
> Kevin
>
> --
> Kevin Walzer
> Code by Kevin/Mobile Code by Kevin
> http://www.codebykevin.com
> http://www.wtmobilesoftware.**com <http://www.wtmobilesoftware.com>
>
>
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From vincent.vandevyvre at swing.be  Sat May 18 10:09:40 2013
From: vincent.vandevyvre at swing.be (Vincent Vande Vyvre)
Date: Sat, 18 May 2013 16:09:40 +0200
Subject: Fwd: Re: python script is not running
In-Reply-To: <519759C7.7000200@swing.be>
References: <519759C7.7000200@swing.be>
Message-ID: <51978BA4.1080000@swing.be>




-------- Message original --------
Sujet: 	Re: python script is not running
Date : 	Sat, 18 May 2013 12:36:55 +0200
De : 	Vincent Vande Vyvre <vincent.vandevyvre at swing.be>
Pour : 	Avnesh Shakya <avnesh.nitk at gmail.com>



Le 18/05/2013 12:12, Avnesh Shakya a ?crit :
> hi,
>      i want to run python script which generating data into json fromat, I am using crontab, but it's not executing...
> my python code--
> try.py --
>
> import json
> import simplejson as json
> import sys
>
> def tryJson():
>      saved = sys.stdout
>      correctFile = file('data.json', 'a+')
>      sys.stdout = correctFile
>      result = []
>      i = 1
>      for i in range(5):
>          info = {
>                  'a': i+1,
>                  'b': i+2,
>                  'c': i+3,
>                 }
>          result.append(info)
>
>      if result:
>          print json.dumps(result, indent=6)
>          sys.stdout = saved
>          correctFile.close()
> tryJson()
>
> now i m doing ion terminal-
> avin at hp:~$ crontab -e
> then type -
> */2 * * * * python /home/avin/data/try.py
>
> and save
>
> but it's not executing.
Have a look at /var/mail/yourname, this is a log created by crontab.

-- 
Vincent V.V.
Oqapy <https://launchpad.net/oqapy> . Qarte
<https://launchpad.net/qarte> . PaQager <https://launchpad.net/paqager>





From phd at phdru.name  Sat May 18 06:08:30 2013
From: phd at phdru.name (Oleg Broytman)
Date: Sat, 18 May 2013 14:08:30 +0400
Subject: SQLObject 1.4.0
Message-ID: <20130518100829.GC9791@iskra.aviel.ru>

Hello!

I'm pleased to announce version 1.4.0, the first stable release of branch
1.4 of SQLObject.


What's new in SQLObject
=======================

Features & Interface
--------------------

* Support for PostgreSQL 8.1 is dropped. The minimal supported version of
  PostgreSQL is 8.2 now.

* Optimization in PostgresConnection: use INSERT...RETURNING id
  to get the autoincremented id in one query instead of two
  (INSERT + SELECT id).

* Changed the way to get if the table has identity in MS SQL.

* NCHAR/NVARCHAR and N''-quoted strings for MS SQL.

Contributors for this release are Ken Lalonde and Andrew Ziem.


For a more complete list, please see the news:
http://sqlobject.org/News.html


What is SQLObject
=================

SQLObject is an object-relational mapper.  Your database tables are described
as classes, and rows are instances of those classes.  SQLObject is meant to be
easy to use and quick to get started with.

SQLObject supports a number of backends: MySQL, PostgreSQL, SQLite,
Firebird, Sybase, MSSQL and MaxDB (also known as SAPDB).


Where is SQLObject
==================

Site:
http://sqlobject.org

Development:
http://sqlobject.org/devel/

Mailing list:
https://lists.sourceforge.net/mailman/listinfo/sqlobject-discuss

Archives:
http://news.gmane.org/gmane.comp.python.sqlobject

Download:
https://pypi.python.org/pypi/SQLObject/1.4.0

News and changes:
http://sqlobject.org/News.html

Oleg.
-- 
     Oleg Broytman            http://phdru.name/            phd at phdru.name
           Programmers don't die, they just GOSUB without RETURN.


From drsalists at gmail.com  Sat May 18 15:01:12 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Sat, 18 May 2013 12:01:12 -0700
Subject: TypeError: unbound method add() must be called with BinaryTree
	instance as first argument (got nothing instead)
Message-ID: <CAGGBd_q6AB8ARcotzu4QpS1N3BwKCOr=PGv6oUewsM=b-j=SEA@mail.gmail.com>

I'm getting the error in the subject, from the following code:
    def add(self, key):
        """
        Adds a node containing I{key} to the subtree
        rooted at I{self}, returning the added node.
        """
        node = self.find(key)
        if not node:
            node.key = key
            # placeholder
            node.left, node.right = self.__class__(parent=node),
self.__class__(parent=node)
            return (False, node)
        else:
            if random.random() < 0.5:
                print('node.left is %s' % node.left)
                return BinaryTree.add(self=node.left, key=key)
            else:
                print('node.right is %s' % node.left)
                return BinaryTree.add(self=node.right, key=key)

The above add() method is part of a BinaryTree(object) class, whose
subclass is RedBlackTree.

We need to explicitly call BinaryTree.add() with an explict self, to avoid
inappropriately calling RedBlackTree.add().; BinaryTree.add() is being
called with a RedBlackTree instance as self.

The debugging print and traceback look like:
node.left is  0 -1 red
Traceback (most recent call last):
  File "app_main.py", line 51, in run_toplevel
  File "test-red_black_tree_mod", line 328, in <module>
    test()
  File "test-red_black_tree_mod", line 316, in test
    all_good &= test_duplicates()
  File "test-red_black_tree_mod", line 194, in test_duplicates
    tree.add(value)
  File
"/home/dstromberg/src/home-svn/red-black-tree-mod/trunk/duncan/red_black_bag_mod.py",
line 919, in add
    (replaced, node) = super(RedBlackTree, self).add(key=key)
  File
"/home/dstromberg/src/home-svn/red-black-tree-mod/trunk/duncan/red_black_bag_mod.py",
line 376, in add
    return BinaryTree.add(self=node.left, key=key)
TypeError: unbound method add() must be called with BinaryTree instance as
first argument (got nothing instead)

Why is it complaining that .add() is getting nothing, when node.left isn't
None?  As you can see above the traceback, it's got a value represented by
"node.left is  0 -1 red".

python 2.x, python 3.x and pypy all give this same error, though jython
errors out at a different point in the same method.

Thanks!
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From __peter__ at web.de  Sat May 18 15:24:46 2013
From: __peter__ at web.de (Peter Otten)
Date: Sat, 18 May 2013 21:24:46 +0200
Subject: TypeError: unbound method add() must be called with BinaryTree
	instance as first argument (got nothing instead)
References: <CAGGBd_q6AB8ARcotzu4QpS1N3BwKCOr=PGv6oUewsM=b-j=SEA@mail.gmail.com>
Message-ID: <kn8khn$o5t$1@ger.gmane.org>

Dan Stromberg wrote:

> I'm getting the error in the subject, from the following code:
>     def add(self, key):
>         """
>         Adds a node containing I{key} to the subtree
>         rooted at I{self}, returning the added node.
>         """
>         node = self.find(key)
>         if not node:
>             node.key = key
>             # placeholder
>             node.left, node.right = self.__class__(parent=node),
> self.__class__(parent=node)
>             return (False, node)
>         else:
>             if random.random() < 0.5:
>                 print('node.left is %s' % node.left)
>                 return BinaryTree.add(self=node.left, key=key)
>             else:
>                 print('node.right is %s' % node.left)
>                 return BinaryTree.add(self=node.right, key=key)
> 
> The above add() method is part of a BinaryTree(object) class, whose
> subclass is RedBlackTree.
> 
> We need to explicitly call BinaryTree.add() with an explict self, to avoid
> inappropriately calling RedBlackTree.add().; BinaryTree.add() is being
> called with a RedBlackTree instance as self.
> 
> The debugging print and traceback look like:
> node.left is  0 -1 red
> Traceback (most recent call last):
>   File "app_main.py", line 51, in run_toplevel
>   File "test-red_black_tree_mod", line 328, in <module>
>     test()
>   File "test-red_black_tree_mod", line 316, in test
>     all_good &= test_duplicates()
>   File "test-red_black_tree_mod", line 194, in test_duplicates
>     tree.add(value)
>   File
> "/home/dstromberg/src/home-svn/red-black-tree-
mod/trunk/duncan/red_black_bag_mod.py",
> line 919, in add
>     (replaced, node) = super(RedBlackTree, self).add(key=key)
>   File
> "/home/dstromberg/src/home-svn/red-black-tree-
mod/trunk/duncan/red_black_bag_mod.py",
> line 376, in add
>     return BinaryTree.add(self=node.left, key=key)
> TypeError: unbound method add() must be called with BinaryTree instance as
> first argument (got nothing instead)
> 
> Why is it complaining that .add() is getting nothing, when node.left isn't
> None?  As you can see above the traceback, it's got a value represented by
> "node.left is  0 -1 red".
> 
> python 2.x, python 3.x and pypy all give this same error, though jython
> errors out at a different point in the same method.
> 
> Thanks!

I never ran into that, but apparently you cannot pass self as a keyword 
parameter:

>>> class A(object):
...     def add(self): pass
... 
>>> a = A()
>>> A.add(a)
>>> A.add(self=a)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unbound method add() must be called with A instance as first 
argument (got nothing instead)




From __peter__ at web.de  Sat May 18 15:46:38 2013
From: __peter__ at web.de (Peter Otten)
Date: Sat, 18 May 2013 21:46:38 +0200
Subject: TypeError: unbound method add() must be called with BinaryTree
	instance as first argument (got nothing instead)
References: <CAGGBd_q6AB8ARcotzu4QpS1N3BwKCOr=PGv6oUewsM=b-j=SEA@mail.gmail.com>
Message-ID: <kn8lqn$sd$1@ger.gmane.org>

Dan Stromberg wrote:

> python 2.x, python 3.x and pypy all give this same error, though jython
> errors out at a different point in the same method.

By the way, 3.x doesn't have unbound methods, so that should work.



From tjreedy at udel.edu  Sat May 18 17:05:57 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sat, 18 May 2013 17:05:57 -0400
Subject: TypeError: unbound method add() must be called with BinaryTree
	instance as first argument (got nothing instead)
In-Reply-To: <kn8lqn$sd$1@ger.gmane.org>
References: <CAGGBd_q6AB8ARcotzu4QpS1N3BwKCOr=PGv6oUewsM=b-j=SEA@mail.gmail.com>
	<kn8lqn$sd$1@ger.gmane.org>
Message-ID: <kn8qfc$bgd$1@ger.gmane.org>

On 5/18/2013 3:46 PM, Peter Otten wrote:
> Dan Stromberg wrote:
>
>> python 2.x, python 3.x and pypy all give this same error, though jython
>> errors out at a different point in the same method.
>
> By the way, 3.x doesn't have unbound methods, so that should work.

It does for this example (3.3.1)
 >>> c = C()
 >>> c.m()
<__main__.C object at 0x00000000033FC5F8>
 >>> C.m(c)
<__main__.C object at 0x00000000033FC5F8>
 >>> C.m(self=c)
<__main__.C object at 0x00000000033FC5F8>





From cs at zip.com.au  Sat May 18 20:26:29 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Sun, 19 May 2013 10:26:29 +1000
Subject: mutable ints: I think I have painted myself into a corner
Message-ID: <20130519002629.GA14025@cskk.homeip.net>

TL;DR: I think I want to modify an int value "in place".

Yesterday I was thinking about various "flag set" objects I have
floating around which are essentially bare "object"s whose attributes
I access, for example:

  flags = object()
  flags.this = True
  flags.that = False

and then elsewhere:

  if flags.that:
    do that ...

Nice and readable, but I thought to myself: so bulky!

The use case for flags is essentially boolean/binary, and so a int
accessed as a bitmask should be smaller.

So I pulled out my BitMask int subclass (which mostly transcribes
the int as "A|B|C" for readability purposes, partly to dillute Nick
Coglan's liking for bulky strings over compact ints on readability
grounds:-), and gave the subclass attribute access.

This works just fine for querying the flags object, with code exactly
like the "if" statement above.

But setting up a flags object? What I _want_ to write is code like this:

  Flags = BitMask('this', 'that')

  # set default state
  flags = Flags()
  flags.this = False
  flags.that = True
  ... iterate over some options ...: flags.this = True

and there's my problem. This would modify the int in place. There's
no way to do that. For the base type (int) this makes perfect sense,
as they're immutable.

Before I toss this approach and retreat to my former "object"
technique, does anyone see a way forward to modify an int subclass
instance in place? (That doesn't break math, preferably; I don't
do arithmetic with these things but they are, after all, ints...)

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Why does "philosophy of consciousness/nature of reality" seem to interest you
so much?  Take away consciousness and reality and there's not much left.
- Greg Egan, interview in Eidolon 15


From rosuav at gmail.com  Sat May 18 21:11:56 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 19 May 2013 11:11:56 +1000
Subject: mutable ints: I think I have painted myself into a corner
In-Reply-To: <20130519002629.GA14025@cskk.homeip.net>
References: <20130519002629.GA14025@cskk.homeip.net>
Message-ID: <CAPTjJmrgFGP=4pHXN7cKRzZ4pNg1Yeki=iPFw9bRLDF-osYAaA@mail.gmail.com>

On Sun, May 19, 2013 at 10:26 AM, Cameron Simpson <cs at zip.com.au> wrote:
> Before I toss this approach and retreat to my former "object"
> technique, does anyone see a way forward to modify an int subclass
> instance in place? (That doesn't break math, preferably; I don't
> do arithmetic with these things but they are, after all, ints...)
>

Why is it an int subclass? Because there are places where you want to
use it as though it were an int? It might be easier to render those,
instead, eg by creating a __int__ method. (Or is it "an __int__
method"? Not sure.)

ChrisA


From cs at zip.com.au  Sat May 18 21:54:04 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Sun, 19 May 2013 11:54:04 +1000
Subject: mutable ints: I think I have painted myself into a corner
In-Reply-To: <CAPTjJmrgFGP=4pHXN7cKRzZ4pNg1Yeki=iPFw9bRLDF-osYAaA@mail.gmail.com>
References: <CAPTjJmrgFGP=4pHXN7cKRzZ4pNg1Yeki=iPFw9bRLDF-osYAaA@mail.gmail.com>
Message-ID: <20130519015404.GA78300@cskk.homeip.net>

On 19May2013 11:11, Chris Angelico <rosuav at gmail.com> wrote:
| On Sun, May 19, 2013 at 10:26 AM, Cameron Simpson <cs at zip.com.au> wrote:
| > Before I toss this approach and retreat to my former "object"
| > technique, does anyone see a way forward to modify an int subclass
| > instance in place? (That doesn't break math, preferably; I don't
| > do arithmetic with these things but they are, after all, ints...)
| 
| Why is it an int subclass? Because there are places where you want to
| use it as though it were an int? It might be easier to render those,
| instead, eg by creating a __int__ method. (Or is it "an __int__
| method"? Not sure.)

I don't want to use it as an int, on the outside. I want to use an
int on the inside as the implementation.

It's an int _subclass_ so that it is no bigger than an int. Otherwise
I may as well just make an ordinary object and be back where I
started.  Bulky:-(

The reason it is an _int_ subclass, versus something else, is that
a bitmap is a type of int. So the functional mapping is direct.

I _do_ _not_ want to operate on it from the outside as an int (doing
overt addition, for example, though I can imagine doing bitwise
activities); I want to operate on in _internally_ as a int to decide
what names-by-an-attribute flags are on or off.

So an object with an __int__() method is right out; it's the wrong
interface because it would mean an int() call (possibly implicit)
in exterior code.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Hoping to shave precious seconds off the time it would take me to get
through the checkout process and on my way home, I opted for the express
line ("9 Items Or Less [sic]"  Why nine items?  Where do they come up with
these rules, anyway?  It's the same way at most stores -- always some
oddball number like that, instead of a more understandable multiple of
five.  Like "five.")
        - Geoff Miller, geoffm at purplehaze.Corp.Sun.COM


From greg.ewing at canterbury.ac.nz  Sun May 19 21:23:28 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Mon, 20 May 2013 13:23:28 +1200
Subject: mutable ints: I think I have painted myself into a corner
In-Reply-To: <mailman.1828.1368928471.3114.python-list@python.org>
References: <CAPTjJmrgFGP=4pHXN7cKRzZ4pNg1Yeki=iPFw9bRLDF-osYAaA@mail.gmail.com>
	<mailman.1828.1368928471.3114.python-list@python.org>
Message-ID: <avtc8iFp5vU1@mid.individual.net>

Cameron Simpson wrote:
> It's an int _subclass_ so that it is no bigger than an int.

If you use __slots__ to eliminate the overhead of an
instance dict, you'll get an object consisting of a
header plus one reference, which is probably about the
size of an int. But you'll also need an int to put in
that slot, so the total size will be about twice that
of an int.

Another approach would be to subclass array.array and
give instances of it type integer and size 1. Together
with empty __slots__, it will probably be a bit bigger
than an int, but it might still be smaller than a
custom object plus an int.

If all of these are still too big, you might need to
find some way of packing multiple instances into a
single array.array.

-- 
Greg


From cs at zip.com.au  Mon May 20 02:07:51 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 20 May 2013 16:07:51 +1000
Subject: mutable ints: I think I have painted myself into a corner
In-Reply-To: <avtc8iFp5vU1@mid.individual.net>
References: <avtc8iFp5vU1@mid.individual.net>
Message-ID: <20130520060751.GA67145@cskk.homeip.net>

On 20May2013 13:23, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
| Cameron Simpson wrote:
| >It's an int _subclass_ so that it is no bigger than an int.
| 
| If you use __slots__ to eliminate the overhead of an
| instance dict, you'll get an object consisting of a
| header plus one reference, which is probably about the
| size of an int. But you'll also need an int to put in
| that slot, so the total size will be about twice that
| of an int.

Yeah, I was thinking I'd need to go that way. Thanks for the
suggestion.

| Another approach would be to subclass array.array and
| give instances of it type integer and size 1. Together
| with empty __slots__, it will probably be a bit bigger
| than an int, but it might still be smaller than a
| custom object plus an int.

Really? Interesting. I thinik it crosses my "too baroque" threshold,
but maybe not:-)

| If all of these are still too big, you might need to
| find some way of packing multiple instances into a
| single array.array.

Space isn't that real an issue at present; I'll keep that kind of
approach in mind if it comes up. This really came up because I was
feeling that the obvious object-with-boolean-attributes was terrbily
wasteful for something that can be inplemented with a single int,
in principle.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

>>>How do you blip the throttle and wave? Do you blip it real high, then wave
>>>before the revs drop back?
>>Blip = right hand; Wave = left hand.  Do both simultaneously.  QED.
>Doesnt this make the bike lurch forward thru the intersection?
Not if the disk lock is in place...
        - Dean Woodward <deanw at agora.rdrop.com>


From __peter__ at web.de  Sun May 19 03:01:49 2013
From: __peter__ at web.de (Peter Otten)
Date: Sun, 19 May 2013 09:01:49 +0200
Subject: mutable ints: I think I have painted myself into a corner
References: <20130519002629.GA14025@cskk.homeip.net>
Message-ID: <kn9tck$k6u$1@ger.gmane.org>

Cameron Simpson wrote:

> TL;DR: I think I want to modify an int value "in place".
> 
> Yesterday I was thinking about various "flag set" objects I have
> floating around which are essentially bare "object"s whose attributes
> I access, for example:
> 
>   flags = object()
>   flags.this = True
>   flags.that = False
> 
> and then elsewhere:
> 
>   if flags.that:
>     do that ...
> 
> Nice and readable, but I thought to myself: so bulky!

Plus, it doesn't work:

>>> object().this = True
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'object' object has no attribute 'this'

> The use case for flags is essentially boolean/binary, and so a int
> accessed as a bitmask should be smaller.
> 
> So I pulled out my BitMask int subclass (which mostly transcribes
> the int as "A|B|C" for readability purposes, partly to dillute Nick
> Coglan's liking for bulky strings over compact ints on readability
> grounds:-), and gave the subclass attribute access.
> 
> This works just fine for querying the flags object, with code exactly
> like the "if" statement above.
> 
> But setting up a flags object? What I _want_ to write is code like this:
> 
>   Flags = BitMask('this', 'that')
> 
>   # set default state
>   flags = Flags()
>   flags.this = False
>   flags.that = True
>   ... iterate over some options ...: flags.this = True
> 
> and there's my problem. This would modify the int in place. There's
> no way to do that. For the base type (int) this makes perfect sense,
> as they're immutable.
> 
> Before I toss this approach and retreat to my former "object"
> technique, does anyone see a way forward to modify an int subclass
> instance in place? (That doesn't break math, preferably; I don't
> do arithmetic with these things but they are, after all, ints...)

No, but you could make

flags = Flags(this=False, that=True)

work.



From cs at zip.com.au  Mon May 20 01:57:51 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 20 May 2013 15:57:51 +1000
Subject: mutable ints: I think I have painted myself into a corner
In-Reply-To: <kn9tck$k6u$1@ger.gmane.org>
References: <kn9tck$k6u$1@ger.gmane.org>
Message-ID: <20130520055751.GA62991@cskk.homeip.net>

On 19May2013 09:01, Peter Otten <__peter__ at web.de> wrote:
| Cameron Simpson wrote:
| 
| > TL;DR: I think I want to modify an int value "in place".
| > 
| > Yesterday I was thinking about various "flag set" objects I have
| > floating around which are essentially bare "object"s whose attributes
| > I access, for example:
| > 
| >   flags = object()
| >   flags.this = True
| >   flags.that = False
| > 
| > and then elsewhere:
| > 
| >   if flags.that:
| >     do that ...
| > 
| > Nice and readable, but I thought to myself: so bulky!
| 
| Plus, it doesn't work:

Yeah, sorry. My "old" code was a trite subclass of object.
The new broken code is a subclass of int.

| > But setting up a flags object? What I _want_ to write is code like this:
| > 
| >   Flags = BitMask('this', 'that')
| > 
| >   # set default state
| >   flags = Flags()
| >   flags.this = False
| >   flags.that = True
| >   ... iterate over some options ...: flags.this = True
| > 
| > and there's my problem. This would modify the int in place. There's
| > no way to do that. For the base type (int) this makes perfect sense,
| > as they're immutable.
| > 
| > Before I toss this approach and retreat to my former "object"
| > technique, does anyone see a way forward to modify an int subclass
| > instance in place? (That doesn't break math, preferably; I don't
| > do arithmetic with these things but they are, after all, ints...)
| 
| No, but you could make
| 
| flags = Flags(this=False, that=True)

Yes, that is true. Flags would need to be a factory function computing
the corresponding bitmask value and then returning my new int, but
it would work. It still wouldn't let me go the whole way of modifying
the flags after instantiation.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Carpe Daemon - Seize the Background Process
        - Paul Tomblin <ab401 at freenet2.carleton.ca>


From antilogeffects at gmail.com  Sun May 19 06:52:27 2013
From: antilogeffects at gmail.com (Anti Log)
Date: Sun, 19 May 2013 03:52:27 -0700 (PDT)
Subject: Harmonic distortion of a input signal
Message-ID: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>

Hi,
I have a task to calculate total distortion of a harmonics, of a signal that i imported from oscilloscope as numpy array. I had no problem drawing its spectrum, and time domain graph, but cant seem to find any functions that calculate TDH.
Any help? 
Best regards


From rosuav at gmail.com  Sun May 19 11:34:53 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 20 May 2013 01:34:53 +1000
Subject: Harmonic distortion of a input signal
In-Reply-To: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
Message-ID: <CAPTjJmrXgUkG1Ts9nm3GGChgeUzgSvkO0ndkWVdWE9hs9DfOqQ@mail.gmail.com>

On Sun, May 19, 2013 at 8:52 PM, Anti Log <antilogeffects at gmail.com> wrote:
> total distortion of a harmonics

I selected this part of your post, right-clicked, and Chrome offered
to do a Google search for those words. And, surprise surprise, the
first hit is a page that appears to have the mathematics behind it.
Now, I don't know how much you trust Google and Wikipedia, but I'm
sure you can confirm the maths in some other way.

My guess is that there's no function in numpy to do what you're
asking... but it shouldn't be too hard to render the formula/e given
into Python code. Python's pretty expressive when it comes to algebra.
:)

ChrisA


From killybeard91 at gmail.com  Sun May 19 18:25:08 2013
From: killybeard91 at gmail.com (killybeard91 at gmail.com)
Date: Sun, 19 May 2013 15:25:08 -0700 (PDT)
Subject: Harmonic distortion of a input signal
In-Reply-To: <mailman.1846.1368977695.3114.python-list@python.org>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<mailman.1846.1368977695.3114.python-list@python.org>
Message-ID: <c841061c-2bae-4e41-bac2-f9cd9606c783@googlegroups.com>

How can i at least find a peek in FFT spectrum of a square wave ? 
>From there i could easily build formula. Sorry for bothering but i am new to Python.



From oscar.j.benjamin at gmail.com  Sun May 19 18:49:52 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Sun, 19 May 2013 23:49:52 +0100
Subject: Harmonic distortion of a input signal
In-Reply-To: <c841061c-2bae-4e41-bac2-f9cd9606c783@googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<mailman.1846.1368977695.3114.python-list@python.org>
	<c841061c-2bae-4e41-bac2-f9cd9606c783@googlegroups.com>
Message-ID: <CAHVvXxQURRKyxAV12YeqmpkkWj7sPC1Eczma6SJidLSjU6w-=g@mail.gmail.com>

On 19 May 2013 23:25,  <killybeard91 at gmail.com> wrote:
> How can i at least find a peek in FFT spectrum of a square wave ?
> From there i could easily build formula. Sorry for bothering but i am new to Python.

Are you the same person who posted the original question?

You probably want to use numpy for this. I'm not sure if I understand
your question but here goes:

First import numpy (you may need to install this first):

>>> import numpy as np

Create a square wave signal:

>>> x = np.zeros(50)
>>> x[:25] = -1
>>> x[25:] = +1
>>> x
array([-1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1.,
       -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1.,  1.,
        1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,
        1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.])

Compute the magnitude spectrum:

>>> spect = abs(np.fft.fft(x)[:25])
>>> spect
array([  0.        ,  31.85194222,   0.        ,  10.67342282,
         0.        ,   6.47213595,   0.        ,   4.69726931,
         0.        ,   3.73254943,   0.        ,   3.13762901,
         0.        ,   2.7436023 ,   0.        ,   2.47213595,
         0.        ,   2.28230601,   0.        ,   2.15105461,
         0.        ,   2.06487174,   0.        ,   2.01589594,   0.        ])

Find the index of the maximum element:

>>> np.argmax(spect)
1

So the peak is the lowest non-zero frequency component of the DFT. In
Hz this corresponds to a frequency of 1/T where T is the duration of
the signal.


Oscar


From tjreedy at udel.edu  Sun May 19 19:19:55 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 19 May 2013 19:19:55 -0400
Subject: Harmonic distortion of a input signal
In-Reply-To: <CAHVvXxQURRKyxAV12YeqmpkkWj7sPC1Eczma6SJidLSjU6w-=g@mail.gmail.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<mailman.1846.1368977695.3114.python-list@python.org>
	<c841061c-2bae-4e41-bac2-f9cd9606c783@googlegroups.com>
	<CAHVvXxQURRKyxAV12YeqmpkkWj7sPC1Eczma6SJidLSjU6w-=g@mail.gmail.com>
Message-ID: <knbmmm$j73$1@ger.gmane.org>

On 5/19/2013 6:49 PM, Oscar Benjamin wrote:

>>>> import numpy as np
>
> Create a square wave signal:
>
>>>> x = np.zeros(50)
>>>> x[:25] = -1
>>>> x[25:] = +1
>>>> x
> array([-1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1.,
>         -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1.,  1.,
>          1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,
>          1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.])
>
> Compute the magnitude spectrum:
>
>>>> spect = abs(np.fft.fft(x)[:25])
>>>> spect
> array([  0.        ,  31.85194222,   0.        ,  10.67342282,
>           0.        ,   6.47213595,   0.        ,   4.69726931,
>           0.        ,   3.73254943,   0.        ,   3.13762901,
>           0.        ,   2.7436023 ,   0.        ,   2.47213595,
>           0.        ,   2.28230601,   0.        ,   2.15105461,
>           0.        ,   2.06487174,   0.        ,   2.01589594,   0.        ])
>
> Find the index of the maximum element:
>
>>>> np.argmax(spect)
> 1
>
> So the peak is the lowest non-zero frequency component of the DFT. In
> Hz this corresponds to a frequency of 1/T where T is the duration of
> the signal.

While you were answering a specific question, I think the above is a 
nice tutorial example, because it is more meaningful than arbitrary 
operations applied to random data.





From killybeard91 at gmail.com  Sun May 19 18:59:17 2013
From: killybeard91 at gmail.com (killybeard91 at gmail.com)
Date: Sun, 19 May 2013 15:59:17 -0700 (PDT)
Subject: Harmonic distortion of a input signal
In-Reply-To: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
Message-ID: <7d4f07c6-7289-4c91-a829-338127862965@googlegroups.com>

Yes, sorry logged from another account.
Would that work on a numpy array ? Because this signal was imported from oscilloscope as a numpy array.
Best regards,


From killybeard91 at gmail.com  Sun May 19 19:03:43 2013
From: killybeard91 at gmail.com (killybeard91 at gmail.com)
Date: Sun, 19 May 2013 16:03:43 -0700 (PDT)
Subject: Harmonic distortion of a input signal
In-Reply-To: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
Message-ID: <a02d7d2a-797f-4e48-8f70-edc40297f119@googlegroups.com>

Got it working, thanks alot :)



From killybeard91 at gmail.com  Sun May 19 19:36:43 2013
From: killybeard91 at gmail.com (killybeard91 at gmail.com)
Date: Sun, 19 May 2013 16:36:43 -0700 (PDT)
Subject: Harmonic distortion of a input signal
In-Reply-To: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
Message-ID: <bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>

One more question. Function np.argmax returns max of non-complex numbers ? 
Because FFT array of my signal is complex.



From oscar.j.benjamin at gmail.com  Sun May 19 19:44:43 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Sun, 19 May 2013 23:44:43 -0000
Subject: Harmonic distortion of a input signal
In-Reply-To: <bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
Message-ID: <CAHVvXxSEJQk6zkqdeO1MmxY0hwTGR6J5LZaeZP5fe1xPRgNUgA@mail.gmail.com>

On 20 May 2013 00:36,  <killybeard91 at gmail.com> wrote:
> One more question. Function np.argmax returns max of non-complex numbers ?
> Because FFT array of my signal is complex.

Use abs() like in my example. This will give the absolute value of the
complex numbers:

>>> z = 1+1j
>>> z
(1+1j)
>>> abs(z)
1.4142135623730951


Oscar


From greg.ewing at canterbury.ac.nz  Sun May 19 21:09:36 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Mon, 20 May 2013 13:09:36 +1200
Subject: Harmonic distortion of a input signal
In-Reply-To: <bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
Message-ID: <avtbeiFk3qU1@mid.individual.net>

killybeard91 at gmail.com wrote:
> One more question. Function np.argmax returns max of non-complex numbers ? 
> Because FFT array of my signal is complex.

You'll want the magnitudes of the complex numbers.
Actually the squares of the magnitudes (assuming the
data from the oscilloscope represents voltages),
because you're after a ratio of powers.

-- 
Greg



From davea at davea.name  Sun May 19 21:11:57 2013
From: davea at davea.name (Dave Angel)
Date: Sun, 19 May 2013 21:11:57 -0400
Subject: Harmonic distortion of a input signal
In-Reply-To: <bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
Message-ID: <5199785D.10900@davea.name>

On 05/19/2013 07:36 PM, killybeard91 at gmail.com wrote:
> One more question. Function np.argmax returns max of non-complex numbers ?
> Because FFT array of my signal is complex.
>

It'd be easier to track the thread if you actually replied to the 
message you're responding to, and also if you included some context. 
But I'll paste the latter in here:

Terry Reedy said:
 > Compute the magnitude spectrum:

 >>> spect = abs(np.fft.fft(x)[:25])
 >>> spect
 > array([  0.        ,  31.85194222,   0.        ,  10.67342282,
 >          0.        ,   6.47213595,   0.        ,   4.69726931,
 >          0.        ,   3.73254943,   0.        ,   3.13762901,
 >          0.        ,   2.7436023 ,   0.        ,   2.47213595,
 >          0.        ,   2.28230601,   0.        ,   2.15105461,
 >          0.        ,   2.06487174,   0.        ,   2.01589594,
 > 0.        ])

 > Find the index of the maximum element:

 >>> np.argmax(spect)
 > 1


Notice that argmax's argument is the result of an abs() call.  It's got 
real numbers representing the magnitude of the various complex numbers.

-- 
DaveA


From wxjmfauth at gmail.com  Mon May 20 13:23:33 2013
From: wxjmfauth at gmail.com (jmfauth)
Date: Mon, 20 May 2013 10:23:33 -0700 (PDT)
Subject: Harmonic distortion of a input signal
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
	<mailman.1853.1369012338.3114.python-list@python.org>
Message-ID: <7fa6c8f1-3a63-4017-9a57-db8516545da0@k3g2000vbn.googlegroups.com>

Non sense.

The discrete fft algorithm is valid only if the number of data
points you transform does correspond to a power of 2 (2**n).

Keywords to the problem: apodization, zero filling, convolution
product, ...

eg. http://en.wikipedia.org/wiki/Convolution

jmf



From auriocus at gmx.de  Mon May 20 13:50:34 2013
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Mon, 20 May 2013 19:50:34 +0200
Subject: Harmonic distortion of a input signal
In-Reply-To: <7fa6c8f1-3a63-4017-9a57-db8516545da0@k3g2000vbn.googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
	<mailman.1853.1369012338.3114.python-list@python.org>
	<7fa6c8f1-3a63-4017-9a57-db8516545da0@k3g2000vbn.googlegroups.com>
Message-ID: <kndnhp$531$1@dont-email.me>

Am 20.05.13 19:23, schrieb jmfauth:
> Non sense.

Dito.

> The discrete fft algorithm is valid only if the number of data
> points you transform does correspond to a power of 2 (2**n).

Where did you get this? The DFT is defined for any integer point number 
the same way.

Just if you want to get it fast, you need to worry about the length. For 
powers of two, there is the classic Cooley-Tukey. But there do exist FFT 
algorithms for any other length. For example, there is the Winograd 
transform for a set of small numbers, there is "mixed-radix" to reduce 
any length which can be factored, and there is finally Bluestein which 
works for any size, even for a prime. All of the aforementioned 
algorithms are O(log n) and are implemented in typical FFT packages. All 
of them should result (up to rounding differences) in the same thing as 
the naive DFT sum. Therefore, today

> Keywords to the problem: apodization, zero filling, convolution
> product, ...

Not for a periodic signal of integer length.

> eg. http://en.wikipedia.org/wiki/Convolution

How long do you read this group?

	Christian



From auriocus at gmx.de  Mon May 20 13:56:05 2013
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Mon, 20 May 2013 19:56:05 +0200
Subject: Harmonic distortion of a input signal
In-Reply-To: <kndnhp$531$1@dont-email.me>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
	<mailman.1853.1369012338.3114.python-list@python.org>
	<7fa6c8f1-3a63-4017-9a57-db8516545da0@k3g2000vbn.googlegroups.com>
	<kndnhp$531$1@dont-email.me>
Message-ID: <kndns4$531$2@dont-email.me>

Oops, I thought we were posting to comp.dsp. Nevertheless, I think 
numpy.fft does mixed-radix (can't check it now)

Am 20.05.13 19:50, schrieb Christian Gollwitzer:
> Am 20.05.13 19:23, schrieb jmfauth:
>> Non sense.
>
> Dito.
>
>> The discrete fft algorithm is valid only if the number of data
>> points you transform does correspond to a power of 2 (2**n).
>
> Where did you get this? The DFT is defined for any integer point number
> the same way.
>
> Just if you want to get it fast, you need to worry about the length. For
> powers of two, there is the classic Cooley-Tukey. But there do exist FFT
> algorithms for any other length. For example, there is the Winograd
> transform for a set of small numbers, there is "mixed-radix" to reduce
> any length which can be factored, and there is finally Bluestein which
> works for any size, even for a prime. All of the aforementioned
> algorithms are O(log n) and are implemented in typical FFT packages. All
> of them should result (up to rounding differences) in the same thing as
> the naive DFT sum. Therefore, today
>
>> Keywords to the problem: apodization, zero filling, convolution
>> product, ...
>
> Not for a periodic signal of integer length.
>
>> eg. http://en.wikipedia.org/wiki/Convolution
>
> How long do you read this group?
>
>      Christian
>



From wxjmfauth at gmail.com  Thu May 23 07:44:55 2013
From: wxjmfauth at gmail.com (jmfauth)
Date: Thu, 23 May 2013 04:44:55 -0700 (PDT)
Subject: Harmonic distortion of a input signal
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
	<mailman.1853.1369012338.3114.python-list@python.org>
	<7fa6c8f1-3a63-4017-9a57-db8516545da0@k3g2000vbn.googlegroups.com>
	<kndnhp$531$1@dont-email.me> <kndns4$531$2@dont-email.me>
Message-ID: <1348a986-7d94-4380-aba0-5ae8558a8c55@h5g2000vbg.googlegroups.com>

On 20 mai, 19:56, Christian Gollwitzer <aurio... at gmx.de> wrote:
> Oops, I thought we were posting to comp.dsp. Nevertheless, I think
> numpy.fft does mixed-radix (can't check it now)
>
> Am 20.05.13 19:50, schrieb Christian Gollwitzer:
>
>
>
>
>
>
>
> > Am 20.05.13 19:23, schrieb jmfauth:
> >> Non sense.
>
> > Dito.
>
> >> The discrete fft algorithm is valid only if the number of data
> >> points you transform does correspond to a power of 2 (2**n).
>
> > Where did you get this? The DFT is defined for any integer point number
> > the same way.
>
> > Just if you want to get it fast, you need to worry about the length. For
> > powers of two, there is the classic Cooley-Tukey. But there do exist FFT
> > algorithms for any other length. For example, there is the Winograd
> > transform for a set of small numbers, there is "mixed-radix" to reduce
> > any length which can be factored, and there is finally Bluestein which
> > works for any size, even for a prime. All of the aforementioned
> > algorithms are O(log n) and are implemented in typical FFT packages. All
> > of them should result (up to rounding differences) in the same thing as
> > the naive DFT sum. Therefore, today
>
> >> Keywords to the problem: apodization, zero filling, convolution
> >> product, ...
>
> > Not for a periodic signal of integer length.
>
> >> eg.http://en.wikipedia.org/wiki/Convolution
>
> > How long do you read this group?
>
> > ? ? ?Christian

------

Forget what I wrote.
I'm understanding what I wanted to say, it is badly
formulated.

jmf



From oscar.j.benjamin at gmail.com  Tue May 21 10:58:15 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Tue, 21 May 2013 15:58:15 +0100
Subject: Harmonic distortion of a input signal
In-Reply-To: <7fa6c8f1-3a63-4017-9a57-db8516545da0@k3g2000vbn.googlegroups.com>
References: <eb271b5d-ee83-4f0e-b8ea-5b129c7cb771@googlegroups.com>
	<bdb22ed6-69a0-48f4-b975-e9af31b72f39@googlegroups.com>
	<mailman.1853.1369012338.3114.python-list@python.org>
	<7fa6c8f1-3a63-4017-9a57-db8516545da0@k3g2000vbn.googlegroups.com>
Message-ID: <CAHVvXxT9W7XRT1_WoraDg1dHdyKjD8QAFQMw2VtR+iQtFNea6A@mail.gmail.com>

On 20 May 2013 18:23, jmfauth <wxjmfauth at gmail.com> wrote:
> Non sense.
>
> The discrete fft algorithm is valid only if the number of data
> points you transform does correspond to a power of 2 (2**n).

As with many of your comments about Python's unicode implementation
you are confusing performance with validity. The DFT is defined and is
a valid invertible map (barring roundoff) for complex vectors of any
integer length. It is also a valid method for understanding the
frequency content of periodic signals. The fastest FFT algorithms are
for vectors whose length is a power of 2 but the other algorithms
produce equally *valid* DFT results.

In the example I posted the computation of the DFT using numpy.fft.fft
was (as far as I could tell) instantaneous. I could use timeit to
discover exactly how many microseconds it took but why when I already
have the results I wanted?

> Keywords to the problem: apodization, zero filling, convolution
> product, ...
>
> eg. http://en.wikipedia.org/wiki/Convolution

These points are not relevant to the example given.


Oscar


From ned at nedbatchelder.com  Sun May 19 07:30:49 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Sun, 19 May 2013 07:30:49 -0400
Subject: What was the project that made you feel skilled in Python?
Message-ID: <5198B7E9.7050505@nedbatchelder.com>

Hi all, I'm trying to come up with more project ideas for intermediate 
learners, somewhat along the lines of 
http://bit.ly/intermediate-python-projects .

So here's a question for people who remember coming up from beginner: as 
you moved from exercises like those in Learn Python the Hard Way, up to 
your own self-guided work on small projects, what project were you 
working on that made you feel independent and skilled?  What program 
first felt like your own work rather than an exercise the teacher had 
assigned?

I don't want anything too large, but big enough that there's room for 
design, and multiple approaches, etc.

Thanks in advance!

--Ned.


From rosuav at gmail.com  Sun May 19 07:48:58 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 19 May 2013 21:48:58 +1000
Subject: What was the project that made you feel skilled in Python?
In-Reply-To: <5198B7E9.7050505@nedbatchelder.com>
References: <5198B7E9.7050505@nedbatchelder.com>
Message-ID: <CAPTjJmpa7vUKkx214E+wsTNAr1Th+V4j0N2iUfQLM44t_y7OOg@mail.gmail.com>

On Sun, May 19, 2013 at 9:30 PM, Ned Batchelder <ned at nedbatchelder.com> wrote:
> Hi all, I'm trying to come up with more project ideas for intermediate
> learners, somewhat along the lines of
> http://bit.ly/intermediate-python-projects .
>
> So here's a question for people who remember coming up from beginner: as you
> moved from exercises like those in Learn Python the Hard Way, up to your own
> self-guided work on small projects, what project were you working on that
> made you feel independent and skilled?  What program first felt like your
> own work rather than an exercise the teacher had assigned?
>
> I don't want anything too large, but big enough that there's room for
> design, and multiple approaches, etc.

Easy answer from me: The Yosemite project. And the code still looks
like a n00b wrote it. (On that subject: Pull requests welcome.)

The code is here: https://github.com/Rosuav/Yosemite

I wrote it in Python because I wanted to be able to run it on either
the Windows box that drives our TV system, or the Linux box that
actually stores the content. And it's still doing that, quite nicely.

Yosemite is a pretty simple system. It's broadly similar to a classic
file-serving web server, but instead of making files available for
download, it invokes them locally. There are plenty of other ways to
achieve this, and I'm by no means sure I picked the best, but that's
where it's at, and it was my first real Python project that's been
published.

ChrisA


From roy at panix.com  Sun May 19 10:05:28 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 19 May 2013 10:05:28 -0400
Subject: What was the project that made you feel skilled in Python?
References: <mailman.1844.1368963057.3114.python-list@python.org>
Message-ID: <roy-5EFF91.10052819052013@news.panix.com>

In article <mailman.1844.1368963057.3114.python-list at python.org>,
 Ned Batchelder <ned at nedbatchelder.com> wrote:

> So here's a question for people who remember coming up from beginner: as 
> you moved from exercises like those in Learn Python the Hard Way, up to 
> your own self-guided work on small projects, what project were you 
> working on that made you feel independent and skilled?  What program 
> first felt like your own work rather than an exercise the teacher had 
> assigned?

IIRC, my first production python projects were a bunch of file parsers.  
We had a bunch of text file formats that we worked with often.  I wrote 
some state-machine based parsers which slurped them up and gave back the 
contents in some useful data structure.

Many of the files were big, so I added an option to write out a pickled 
version of the data.  The parsing code could then check to see if there 
was a pickle file that was newer than the text version and read that 
instead.  Big win for speed.

Then, of course, a bunch of utilities which used this data to do useful 
things.  I remember one of the utilities that turned out to be really 
popular was a smart data file differ.  You feed it two files and it 
would tell you how they differed (in a way that was more useful than a 
plain text-based diff).


From neilc at norwich.edu  Mon May 20 11:16:55 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 20 May 2013 15:16:55 GMT
Subject: What was the project that made you feel skilled in Python?
References: <mailman.1844.1368963057.3114.python-list@python.org>
Message-ID: <avut37F9rshU1@mid.individual.net>

On 2013-05-19, Ned Batchelder <ned at nedbatchelder.com> wrote:
> Hi all, I'm trying to come up with more project ideas for
> intermediate learners, somewhat along the lines of 
> http://bit.ly/intermediate-python-projects .
>
> So here's a question for people who remember coming up from
> beginner: as you moved from exercises like those in Learn
> Python the Hard Way, up to your own self-guided work on small
> projects, what project were you working on that made you feel
> independent and skilled?  What program first felt like your own
> work rather than an exercise the teacher had assigned?
>
> I don't want anything too large, but big enough that there's
> room for design, and multiple approaches, etc.

I wrote a library supporting fixed length field tabular data
files. It supports reading specifications for such data files
using configparser for maximum verbosity, plus a few other
shorthand specification formats for brevity. Due to the nature of
my work I need this library in virtually all my other projects,
so I consider it a personal success and found it interesting to
build.

Similar packages on PYPI made many different design decisions
from the ones I did, so it seems like fruitful design discussion
points could arise.

For example, two major design goals in the beginning where: 1.
Ape the interface of the csv module as much as possible. 2.
Support type declarations.

The former was a big success. I've had instances were switching
from csv to a fixed file required changing one line, and of
course if a person were learning the library their knowledge of
reader, writer, DictReader and DictWriter would help.

The latter design goal was a failure. Most published fixed-length
data file specifications include data types, so it seemed
natural. But after trying to write programs using an early
version I ended up removing all traces of that functionality.

One advantage of this idea as a project for an intermediate
programmer is that the implementation is not complicated; most of
the fun is in the design.

-- 
Neil Cerutti


From demianbrecht at gmail.com  Mon May 20 15:20:21 2013
From: demianbrecht at gmail.com (Demian Brecht)
Date: Mon, 20 May 2013 12:20:21 -0700
Subject: What was the project that made you feel skilled in Python?
In-Reply-To: <5198B7E9.7050505@nedbatchelder.com>
References: <5198B7E9.7050505@nedbatchelder.com>
Message-ID: <CAE+T62boSDsnvaS0ih72tYxBpSUeH1h7TghetRRz5dWU4YMJaA@mail.gmail.com>

TBH, I think that the first thing that I did that made me feel that I
could hold my own was when I had my first (and only thus far) patch
accepted into the stdlib. To me, there's a /big/ difference between
throwing together a package that a few people may find useful and
putting a patch together that's accepted by a particular module expert
and committed to the stdlib.

To intermediate learners, I would strongly advocate getting their
hands dirty with some part of the stdlib. Really (imho), there's
really no better place to learn. Yes, in whole, it's a large project,
but there are quite a few small(er) modules that, once their
environment is set up, are self-contained and easy to follow along.
Even if they don't get anything committed, learning from Python
experts is far more useful than any other path that I've personally
taken.

Having said that, another great learning experience for me was when I
wrote my OAuth 2.0 client (https://github.com/demianbrecht/sanction)
and brought the initial implementation (460'ish LoC) to 66 LoC
(pre-2/3 support). In part, this was due to taking a different design
approach, but it was also in part due to taking advantage of Python
idioms rather than simply using approaches that I had used in other
languages.

On Sun, May 19, 2013 at 4:30 AM, Ned Batchelder <ned at nedbatchelder.com> wrote:
> Hi all, I'm trying to come up with more project ideas for intermediate
> learners, somewhat along the lines of
> http://bit.ly/intermediate-python-projects .
>
> So here's a question for people who remember coming up from beginner: as you
> moved from exercises like those in Learn Python the Hard Way, up to your own
> self-guided work on small projects, what project were you working on that
> made you feel independent and skilled?  What program first felt like your
> own work rather than an exercise the teacher had assigned?
>
> I don't want anything too large, but big enough that there's room for
> design, and multiple approaches, etc.
>
> Thanks in advance!
>
> --Ned.
> --
> http://mail.python.org/mailman/listinfo/python-list



-- 
Demian Brecht
http://demianbrecht.github.com


From thomasmurphymusic at gmail.com  Mon May 20 15:36:09 2013
From: thomasmurphymusic at gmail.com (Thomas Murphy)
Date: Mon, 20 May 2013 15:36:09 -0400
Subject: What was the project that made you feel skilled in Python?
In-Reply-To: <CAE+T62boSDsnvaS0ih72tYxBpSUeH1h7TghetRRz5dWU4YMJaA@mail.gmail.com>
References: <5198B7E9.7050505@nedbatchelder.com>
	<CAE+T62boSDsnvaS0ih72tYxBpSUeH1h7TghetRRz5dWU4YMJaA@mail.gmail.com>
Message-ID: <CAEcwjcx5nj2AuBfaGx8TeircvQAV+U_i=1+krjK5QCOtzETr3Q@mail.gmail.com>

Hi Demian,

Can I ask what you mean by working through the stdlib? As in writing
code pieces utilizing each module from the stdlib? Also, you're
talking about "patches" in the stdlib? Is there a separate library of
patches? Forgive me if I'm google-failing hard over here.


From tjreedy at udel.edu  Mon May 20 16:03:05 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Mon, 20 May 2013 16:03:05 -0400
Subject: What was the project that made you feel skilled in Python?
In-Reply-To: <CAEcwjcx5nj2AuBfaGx8TeircvQAV+U_i=1+krjK5QCOtzETr3Q@mail.gmail.com>
References: <5198B7E9.7050505@nedbatchelder.com>
	<CAE+T62boSDsnvaS0ih72tYxBpSUeH1h7TghetRRz5dWU4YMJaA@mail.gmail.com>
	<CAEcwjcx5nj2AuBfaGx8TeircvQAV+U_i=1+krjK5QCOtzETr3Q@mail.gmail.com>
Message-ID: <kndvhi$p6b$1@ger.gmane.org>

On 5/20/2013 3:36 PM, Thomas Murphy wrote:
>
> talking about "patches" in the stdlib? Is there a separate library of
> patches?

http://bugs.python.org
http://docs.python.org/devguide/





From ben+python at benfinney.id.au  Wed May 22 09:05:58 2013
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 22 May 2013 23:05:58 +1000
Subject: What was the project that made you feel skilled in Python?
References: <5198B7E9.7050505@nedbatchelder.com>
Message-ID: <7w61ybdv0p.fsf@benfinney.id.au>

Ned Batchelder <ned at nedbatchelder.com> writes:

> as you moved from exercises like those in Learn Python the Hard Way,
> up to your own self-guided work on small projects, what project were
> you working on that made you feel independent and skilled?  What
> program first felt like your own work rather than an exercise the
> teacher had assigned?

I wanted to simulate a particular board game, and had others in mind
with some common mechanics.

This resulted in a library for rolling dice in different combinations,
and looking up result tables <URL:https://pypi.python.org/pypi/alea>.

Eventually I wanted to extend it to know about custom decks of cards,
and the different ways those are handled in board games.

The unifying theme was a library of routines for simulating the random
elements (dice, cards, tables, spinners, etc.) in any board game.

A little over-engineered, I'll freely admit. But it did give me a sense
of being at home in Python and knowing that this is a good language for
getting things done the right way.

-- 
 \     ?Creativity can be a social contribution, but only in so far as |
  `\            society is free to use the results.? ?Richard Stallman |
_o__)                                                                  |
Ben Finney



From rosuav at gmail.com  Wed May 22 10:43:23 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 00:43:23 +1000
Subject: What was the project that made you feel skilled in Python?
In-Reply-To: <7w61ybdv0p.fsf@benfinney.id.au>
References: <5198B7E9.7050505@nedbatchelder.com>
	<7w61ybdv0p.fsf@benfinney.id.au>
Message-ID: <CAPTjJmr0n71wtST=ChcHJMDp6dE6CaUdZyVi4yAqp+XV47EbHA@mail.gmail.com>

On Wed, May 22, 2013 at 11:05 PM, Ben Finney <ben+python at benfinney.id.au> wrote:
> I wanted to simulate a particular board game, and had others in mind
> with some common mechanics.
>
> This resulted in a library for rolling dice in different combinations,
> and looking up result tables <URL:https://pypi.python.org/pypi/alea>.

Fun fun! Of course, when I hear "rolling dice in different
combinations", my mind immediately turns to Dungeons and Dragons,
where it's plausible to roll d20+7, then roll 2d8+d6+12 to figure out
how much damage you did...

But the hard part of board games is usually the board. I used to spend
ages trying to draw up a half-decent board, and ended up giving up. By
"simulate", I'm guessing you mean that you didn't actually draw
anything of the sort?

ChrisA


From ben+python at benfinney.id.au  Thu May 23 19:32:38 2013
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 24 May 2013 09:32:38 +1000
Subject: What was the project that made you feel skilled in Python?
References: <5198B7E9.7050505@nedbatchelder.com>
	<7w61ybdv0p.fsf@benfinney.id.au>
	<CAPTjJmr0n71wtST=ChcHJMDp6dE6CaUdZyVi4yAqp+XV47EbHA@mail.gmail.com>
Message-ID: <7w1u8xuvah.fsf@benfinney.id.au>

Chris Angelico <rosuav at gmail.com> writes:

> Ben Finney <ben+python at benfinney.id.au> wrote:
> > This resulted in a library for rolling dice in different
> > combinations, and looking up result tables
> > <URL:https://pypi.python.org/pypi/alea>.
>
> Fun fun! Of course, when I hear "rolling dice in different
> combinations", my mind immediately turns to Dungeons and Dragons,
> where it's plausible to roll d20+7, then roll 2d8+d6+12 to figure out
> how much damage you did...

Yeah, and lots of board games use custom dice with faces specific to
that game (symbols, non-consecutive numbers, etc.), so the Die class
allows the faces to be any object the application needs.

> But the hard part of board games is usually the board.

A lot of the board games I'm intrigued by don't have much of a board;
they use custom cards and tokens and (maybe) dice, and the ?board? is an
abstraction of where all the pieces are on the table.

> I used to spend ages trying to draw up a half-decent board, and ended
> up giving up. By "simulate", I'm guessing you mean that you didn't
> actually draw anything of the sort?

Right. The (never completed) application was to simulate the mechanics
of that particular game so I could see how it would play out, not be an
interactive playable game.

I've long been aware there is an enormous amount of UI-programming work
involved with interactive playable games. My ambition for that work was
quenched from attempting it in my teenage years :-)

-- 
 \        ?With Lisp or Forth, a master programmer has unlimited power |
  `\     and expressiveness. With Python, even a regular guy can reach |
_o__)                               for the stars.? ?Raymond Hettinger |
Ben Finney



From tjreedy at udel.edu  Wed May 22 15:52:14 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Wed, 22 May 2013 15:52:14 -0400
Subject: What was the project that made you feel skilled in Python?
In-Reply-To: <7w61ybdv0p.fsf@benfinney.id.au>
References: <5198B7E9.7050505@nedbatchelder.com>
	<7w61ybdv0p.fsf@benfinney.id.au>
Message-ID: <knj7l5$qak$1@ger.gmane.org>

On 5/22/2013 9:05 AM, Ben Finney wrote:

> I wanted to simulate a particular board game, and had others in mind
> with some common mechanics.
>
> This resulted in a library for rolling dice in different combinations,
> and looking up result tables <URL:https://pypi.python.org/pypi/alea>.

Have you cosidered adding a description so it can be found be a search?
A 3.3 version?

"Simulate game randomizers and lookup: dice rolls, card drawing, 
spinners, ...

> Eventually I wanted to extend it to know about custom decks of cards,
> and the different ways those are handled in board games.
>
> The unifying theme was a library of routines for simulating the random
> elements (dice, cards, tables, spinners, etc.) in any board game.
>
> A little over-engineered, I'll freely admit. But it did give me a sense
> of being at home in Python and knowing that this is a good language for
> getting things done the right way.
>




From nicholas.cole at gmail.com  Sat May 25 04:17:08 2013
From: nicholas.cole at gmail.com (Nicholas Cole)
Date: Sat, 25 May 2013 09:17:08 +0100
Subject: What was the project that made you feel skilled in Python?
In-Reply-To: <5198B7E9.7050505@nedbatchelder.com>
References: <5198B7E9.7050505@nedbatchelder.com>
Message-ID: <CAAu18hdtQm3wcWcQ8isJEZ3QDqFaY0s5n_bNK8zFt-Fsdb7juA@mail.gmail.com>

On Sun, May 19, 2013 at 12:30 PM, Ned Batchelder <ned at nedbatchelder.com>wrote:

> Hi all, I'm trying to come up with more project ideas for intermediate
> learners, somewhat along the lines of http://bit.ly/intermediate-**
> python-projects <http://bit.ly/intermediate-python-projects> .
>
> So here's a question for people who remember coming up from beginner: as
> you moved from exercises like those in Learn Python the Hard Way, up to
> your own self-guided work on small projects, what project were you working
> on that made you feel independent and skilled?  What program first felt
> like your own work rather than an exercise the teacher had assigned?


I had been doing some part-time work on server administration while I was a
graduate student, and had written a python library to help display
user-interfaces for some of the scripts we used internally.  At some point,
I discovered that as I had originally written it, I was triggering a small
memory leak, caused by the interaction between python and the underlying
curses c library.  In the real world, it would never have mattered, but I
minded very much that the problem existed at all.

To fix the fault required rewriting the whole library from scratch, and I
did the initial version of this while on a long train journey away from
internet access.  I could have just left it -- for the scripts we were
running it didn't matter at all -- but it was a matter of pride to write
code that didn't behave badly, even in theory.

I ended up putting the code online, and 8 years and a huge number of public
releases later it still seems to be useful to a few people, and I've
learned an awful lot doing it.  I think my proudest "python" moment was
when I first got a bug report from someone I didn't know.

http://code.google.com/p/npyscreen/

Best wishes,

N.
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From dreamingforward at gmail.com  Sun May 26 00:28:24 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Sat, 25 May 2013 21:28:24 -0700
Subject: What was the project that made you feel skilled in Python?
In-Reply-To: <CAAu18hdtQm3wcWcQ8isJEZ3QDqFaY0s5n_bNK8zFt-Fsdb7juA@mail.gmail.com>
References: <5198B7E9.7050505@nedbatchelder.com>
	<CAAu18hdtQm3wcWcQ8isJEZ3QDqFaY0s5n_bNK8zFt-Fsdb7juA@mail.gmail.com>
Message-ID: <CAMjeLr-O7zvYCe7qhr+Lj+TfuNGUMO29EAqwermEwJOBu-4HpA@mail.gmail.com>

Building a Set class (this was before python had them built-in).  Such
exercise stimulates thinking on designing objects that could be part
of the standard library, the questions that arise on API design,
questions on efficiency of implementation.

Then a graph class which can be built from your newly-built set module.

Mark
Tacoma, Washington

On 5/25/13, Nicholas Cole <nicholas.cole at gmail.com> wrote:
> On Sun, May 19, 2013 at 12:30 PM, Ned Batchelder
> <ned at nedbatchelder.com>wrote:
>
>> Hi all, I'm trying to come up with more project ideas for intermediate
>> learners, somewhat along the lines of http://bit.ly/intermediate-**
>> python-projects <http://bit.ly/intermediate-python-projects> .
>>
>> So here's a question for people who remember coming up from beginner: as
>> you moved from exercises like those in Learn Python the Hard Way, up to
>> your own self-guided work on small projects, what project were you
>> working
>> on that made you feel independent and skilled?  What program first felt
>> like your own work rather than an exercise the teacher had assigned?
>
>
> I had been doing some part-time work on server administration while I was a
> graduate student, and had written a python library to help display
> user-interfaces for some of the scripts we used internally.  At some point,
> I discovered that as I had originally written it, I was triggering a small
> memory leak, caused by the interaction between python and the underlying
> curses c library.  In the real world, it would never have mattered, but I
> minded very much that the problem existed at all.
>
> To fix the fault required rewriting the whole library from scratch, and I
> did the initial version of this while on a long train journey away from
> internet access.  I could have just left it -- for the scripts we were
> running it didn't matter at all -- but it was a matter of pride to write
> code that didn't behave badly, even in theory.
>
> I ended up putting the code online, and 8 years and a huge number of public
> releases later it still seems to be useful to a few people, and I've
> learned an awful lot doing it.  I think my proudest "python" moment was
> when I first got a bug report from someone I didn't know.
>
> http://code.google.com/p/npyscreen/
>
> Best wishes,
>
> N.
>


-- 
MarkJ
Tacoma, Washington


From avnesh.nitk at gmail.com  Sun May 19 23:54:11 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Sun, 19 May 2013 20:54:11 -0700 (PDT)
Subject: How to run a python script twice randomly in a day?
Message-ID: <8a44bb69-5e8c-4725-a0c8-505b3ecc1d89@googlegroups.com>

hi,
   How to run a python script twice randomly in a day? Actually I want to run my script randomly in a day and twice only. Please help me.. how is it possible.

Thanks


From jsf80238 at gmail.com  Mon May 20 00:27:15 2013
From: jsf80238 at gmail.com (Jason Friedman)
Date: Sun, 19 May 2013 22:27:15 -0600
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <8a44bb69-5e8c-4725-a0c8-505b3ecc1d89@googlegroups.com>
References: <8a44bb69-5e8c-4725-a0c8-505b3ecc1d89@googlegroups.com>
Message-ID: <CANy1k1gVQpY-hoaCPg6bQC8Lm7oCqRZLS01kwdp=-dCpSUVM+Q@mail.gmail.com>

>    How to run a python script twice randomly in a day? Actually I want to run my script randomly in a day and twice only

I can think of two basic approaches.
One, use crontab or some other similar functionality to call it exactly twice.
Two, use crontab or some other similar functionality to call it every
minute, and add code to your script to execute exactly twice.
Which are you preferring?


From cs at zip.com.au  Mon May 20 00:12:05 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 20 May 2013 14:12:05 +1000
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <8a44bb69-5e8c-4725-a0c8-505b3ecc1d89@googlegroups.com>
References: <8a44bb69-5e8c-4725-a0c8-505b3ecc1d89@googlegroups.com>
Message-ID: <20130520041205.GA97845@cskk.homeip.net>

On 19May2013 20:54, Avnesh Shakya <avnesh.nitk at gmail.com> wrote:
|    How to run a python script twice randomly in a day? Actually
| I want to run my script randomly in a day and twice only. Please
| help me.. how is it possible.

Do you mean "run twice a day, each at random times"?

If so, do the obvious: at midnight, pick two random times. Sleep
until the first time, run the script, sleep until the second time,
run the script.

There are various ways to do the sleeping and midnight bits; they're
up to you.

Enjoy,
-- 
Cameron Simpson <cs at zip.com.au>

The ZZR-1100 is not the bike for me, but the day they invent "nerf" roads
and ban radars I'll be the first in line......AMCN


From cs at zip.com.au  Mon May 20 03:40:02 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 20 May 2013 17:40:02 +1000
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <CAEA17ELY4nCF-kt8+9O1b66wxwCiB3vzTcoxQ8g3qE9CZxdpmw@mail.gmail.com>
References: <CAEA17ELY4nCF-kt8+9O1b66wxwCiB3vzTcoxQ8g3qE9CZxdpmw@mail.gmail.com>
Message-ID: <20130520074002.GA20235@cskk.homeip.net>

On 20May2013 09:47, Avnesh Shakya <avnesh.nitk at gmail.com> wrote:
| On Mon, May 20, 2013 at 9:42 AM, Cameron Simpson <cs at zip.com.au> wrote:
| > On 19May2013 20:54, Avnesh Shakya <avnesh.nitk at gmail.com> wrote:
| > |    How to run a python script twice randomly in a day? Actually
| > | I want to run my script randomly in a day and twice only. Please
| > | help me.. how is it possible.
| >
| > Do you mean "run twice a day, each at random times"?
| >
| > If so, do the obvious: at midnight, pick two random times. Sleep
| > until the first time, run the script, sleep until the second time,
| > run the script.
| >
| > There are various ways to do the sleeping and midnight bits; they're
| > up to you.
|
| Thanks, Can you mail documentation or link for it? I am totally new for it.

1: Please reply on-list; you asked the list, the discussion should
   remain there. I have added the list to the CC line.

2: Please don't top-post. Quote only the relevant bits of the
   previous message and reply below. If the message is long, do
   that in pieces. [quote] reply [quote] reply. Like a conversation.

Now, to your questions.

A UNIX user would use "cron" to schedule the midnight job and from
the midnight job then probably use "at" to schedule the other jobs
to run at specific times. See "man 1 crontab", "man 5 crontab" to
submit the cron jobs and "man at" to submit the once off jobs.

UNIX means Linux, Solaris, AIX, any of the BSDs (includes MacOSX),
etc.

You could a small python script for the midnight job, and it would
submit the "at" jobs. See the "random" module to compute a pseudorandom
number (and thus a random time), the "datetime" module to compute
the dates and times from that number, and the "subprocess" module
to submit the "at" job for the chosen run times. The modules are
here:

  http://docs.python.org/3/py-modindex.html

That presumes python 3; if you're using python 2 the docs for that
are available at the same web site.

You don't need to use "at". Your midnight job could just compute
the time in seconds to each job time, then use the "time.sleep"
function to delay until then. See the "time" module at the above
link.

Nobody on this list will write your program for you.

Attempt to write the program, then come to the list with your attempt
and any problems. People will help if you've made an initial effort,
and continue to try. This question has the "feel" of a homework
question; the point of homework is for you to learn by solving a
problem yourself. It is fine to seek help, but you must make the
effort yourself.

Come back with specific questions.

Cheers,
--
Cameron Simpson <cs at zip.com.au>

I'm not weird; I'm gifted.


From cs at zip.com.au  Mon May 20 21:12:20 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Tue, 21 May 2013 11:12:20 +1000
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <CAEA17E+UpccfENQJEZv_Pp+5P00PUnhHvdztZ0ofMJZF67fdVA@mail.gmail.com>
References: <CAEA17E+UpccfENQJEZv_Pp+5P00PUnhHvdztZ0ofMJZF67fdVA@mail.gmail.com>
Message-ID: <20130521011220.GA62488@cskk.homeip.net>

On 20May2013 15:05, Avnesh Shakya <avnesh.nitk at gmail.com> wrote:
|     Thanks a lot.

No worries, but ...

AGAIN:
- please DO NOT top post. Post below, trimming the quoted material.
- please POST TO THE LIST, not just to me. This is a public discussion.

Now...

| I did something.
| I have created test.sh file in which i put-
| 
| #!/bin/bash
| cd /home/avin/cronJob
| python try.py

Ok, good. Some minor remarks:

Personally, I always use:

  #!/bin/sh

instead of requiring bash. All UNIX systems have sh, bash is only
common. And even when present, it may not be in /bin. /bin/sh is
always there, and unless you're doing something quite unusual, it
works just fine.

| then i went on terminal -
| and run crontab -e
| and wrote-
|   */2 * * * * bash /home/avin/cronJob/test.sh
| and saved it.

IIRC, this runs every two minutes. Good for testing, but not your original spec.

Also, if you make the shell script (test.sh) executable you do not
need to specify the interpreter. Treat your script like any other
command! So:

  chmod +rx /home/avin/cronJob/test.sh

and then your cron line can look like this:

  */2 * * * * /home/avin/cronJob/test.sh

Also, treat your script the same way as your shell script, start
it with a #!  like this:

  #!/usr/bin/python

Make it executable:

  chmod +rx /home/avin/cronJob/try.py

and then you don't need to say "python" in your shell script:

  ./try.py

(You need the ./ because the current directory is not in your command
search path ($PATH).)

| It's working fine.
| but when I m using like
| 
| import random
| a = random.randrange(0, 59)
| */a * * * * bash /home/avin/cronJob/test.sh
| then it's showing error becose of varable 'a', so now how can i take
| variable?

I take it that this is your python program intended to schedule the two randomly timed runs?

As a start, it must all be python. The first two lines are. The third line is
a crontab line.

So as a start, you need to look more like this:

  #!/usr/bin/python
  import random
  a = random.randrange(0, 59)
  cronline = '*/%d * * * * /home/avin/cronJob/test.sh' % (a,)
  print(cronline)

At least then you can see the cron line you're making. It still
does not add it to a cron job.

Some remarks:

- randrange() is like other python ranges: it does not include the end value.
  So your call picks a number from 0..58, not 0..59.
  Say randrange(0,60). Think "start, length".

- My recollection is that you wanted to run a script twice a day at random times.
  Your cron line doesn't do that.

- If you're picking random run times you want to schedule a once-off
  job for each to run at a particular times. Cron schedules repeating
  jobs.  To run at a particular time you want an "at" job.

- You need to do one of two things in the pick-a-time script:
    - pick a time, then sleep until that time and then directly
      invoke the try.py script
  or
    - pick a time, then use the "at" command to schedule the try.py
      (or test.sh) script.

The first approach would look a bit like this (totally untested):

  #!/usr/bin/python
  import random
  import subporcess
  import time
  # choose range time in the next 24 hours
  when = random.randrange(0, 24 * 3600)
  # sleep that many seconds
  time.sleep(when)
  subprocess.call(['/home/avin/cronJob/test.sh'])

For two runs, pick two times. Swap them into order. Sleep twice,
once until the first time and then once until the second time. Etc.

The second approach (using "at") would not sleep. instead, compute
(using the datetime module) the date and time each job should run,
and invoke "at" using the subprocess module, piping the text
"/home/avin/cronJob/test.sh\n" to it.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

On a related topic, has anyone looked at doing a clean-room copy of CSS
a la RC2 and RC4 a few years back?  I know one or two people have
looked at this in an informal manner, but we couldn't find anyone who
hadn't already seen the DeCSS code to act as the clean person (it says
a lot for the status of their "trade secret" that we couldn't actually
find anyone who didn't already know  it).
        - Peter Gutmann <pgut001 at cs.auckland.ac.nz>


From avnesh.nitk at gmail.com  Tue May 21 00:36:00 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Tue, 21 May 2013 10:06:00 +0530
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <20130521011220.GA62488@cskk.homeip.net>
References: <CAEA17E+UpccfENQJEZv_Pp+5P00PUnhHvdztZ0ofMJZF67fdVA@mail.gmail.com>
	<20130521011220.GA62488@cskk.homeip.net>
Message-ID: <CAEA17EKTtis69Nmjux6HOrEV+Zftdc_qDA2yAD=j_VYUGXQ0Yg@mail.gmail.com>

Thanks a lot. I got it.


On Tue, May 21, 2013 at 6:42 AM, Cameron Simpson <cs at zip.com.au> wrote:

> On 20May2013 15:05, Avnesh Shakya <avnesh.nitk at gmail.com> wrote:
> |     Thanks a lot.
>
> No worries, but ...
>
> AGAIN:
> - please DO NOT top post. Post below, trimming the quoted material.
> - please POST TO THE LIST, not just to me. This is a public discussion.
>
> Now...
>
> | I did something.
> | I have created test.sh file in which i put-
> |
> | #!/bin/bash
> | cd /home/avin/cronJob
> | python try.py
>
> Ok, good. Some minor remarks:
>
> Personally, I always use:
>
>   #!/bin/sh
>
> instead of requiring bash. All UNIX systems have sh, bash is only
> common. And even when present, it may not be in /bin. /bin/sh is
> always there, and unless you're doing something quite unusual, it
> works just fine.
>
> | then i went on terminal -
> | and run crontab -e
> | and wrote-
> |   */2 * * * * bash /home/avin/cronJob/test.sh
> | and saved it.
>
> IIRC, this runs every two minutes. Good for testing, but not your original
> spec.
>
> Also, if you make the shell script (test.sh) executable you do not
> need to specify the interpreter. Treat your script like any other
> command! So:
>
>   chmod +rx /home/avin/cronJob/test.sh
>
> and then your cron line can look like this:
>
>   */2 * * * * /home/avin/cronJob/test.sh
>
> Also, treat your script the same way as your shell script, start
> it with a #!  like this:
>
>   #!/usr/bin/python
>
> Make it executable:
>
>   chmod +rx /home/avin/cronJob/try.py
>
> and then you don't need to say "python" in your shell script:
>
>   ./try.py
>
> (You need the ./ because the current directory is not in your command
> search path ($PATH).)
>
> | It's working fine.
> | but when I m using like
> |
> | import random
> | a = random.randrange(0, 59)
> | */a * * * * bash /home/avin/cronJob/test.sh
> | then it's showing error becose of varable 'a', so now how can i take
> | variable?
>
> I take it that this is your python program intended to schedule the two
> randomly timed runs?
>
> As a start, it must all be python. The first two lines are. The third line
> is
> a crontab line.
>
> So as a start, you need to look more like this:
>
>   #!/usr/bin/python
>   import random
>   a = random.randrange(0, 59)
>   cronline = '*/%d * * * * /home/avin/cronJob/test.sh' % (a,)
>   print(cronline)
>
> At least then you can see the cron line you're making. It still
> does not add it to a cron job.
>
> Some remarks:
>
> - randrange() is like other python ranges: it does not include the end
> value.
>   So your call picks a number from 0..58, not 0..59.
>   Say randrange(0,60). Think "start, length".
>
> - My recollection is that you wanted to run a script twice a day at random
> times.
>   Your cron line doesn't do that.
>
> - If you're picking random run times you want to schedule a once-off
>   job for each to run at a particular times. Cron schedules repeating
>   jobs.  To run at a particular time you want an "at" job.
>
> - You need to do one of two things in the pick-a-time script:
>     - pick a time, then sleep until that time and then directly
>       invoke the try.py script
>   or
>     - pick a time, then use the "at" command to schedule the try.py
>       (or test.sh) script.
>
> The first approach would look a bit like this (totally untested):
>
>   #!/usr/bin/python
>   import random
>   import subporcess
>   import time
>   # choose range time in the next 24 hours
>   when = random.randrange(0, 24 * 3600)
>   # sleep that many seconds
>   time.sleep(when)
>   subprocess.call(['/home/avin/cronJob/test.sh'])
>
> For two runs, pick two times. Swap them into order. Sleep twice,
> once until the first time and then once until the second time. Etc.
>
> The second approach (using "at") would not sleep. instead, compute
> (using the datetime module) the date and time each job should run,
> and invoke "at" using the subprocess module, piping the text
> "/home/avin/cronJob/test.sh\n" to it.
>
> Cheers,
> --
> Cameron Simpson <cs at zip.com.au>
>
> On a related topic, has anyone looked at doing a clean-room copy of CSS
> a la RC2 and RC4 a few years back?  I know one or two people have
> looked at this in an informal manner, but we couldn't find anyone who
> hadn't already seen the DeCSS code to act as the clean person (it says
> a lot for the status of their "trade secret" that we couldn't actually
> find anyone who didn't already know  it).
>         - Peter Gutmann <pgut001 at cs.auckland.ac.nz>
>
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From rosuav at gmail.com  Tue May 21 03:56:27 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 21 May 2013 17:56:27 +1000
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <20130521011220.GA62488@cskk.homeip.net>
References: <CAEA17E+UpccfENQJEZv_Pp+5P00PUnhHvdztZ0ofMJZF67fdVA@mail.gmail.com>
	<20130521011220.GA62488@cskk.homeip.net>
Message-ID: <CAPTjJmp4VWi_e-TmyvB=o05jfFRB=hE7FzJLm-XjGBJaZBjXmw@mail.gmail.com>

On Tue, May 21, 2013 at 11:12 AM, Cameron Simpson <cs at zip.com.au> wrote:
> Ok, good. Some minor remarks:
>
> Personally, I always use:
>
>   #!/bin/sh
>
> instead of requiring bash. All UNIX systems have sh, bash is only
> common. And even when present, it may not be in /bin. /bin/sh is
> always there, and unless you're doing something quite unusual, it
> works just fine.

Also, on many systems, /bin/sh is a much lighter interpreter than bash
(eg Debian uses dash). It's more efficient to use that when you can,
even if you use bash for your login shell.

> On 20May2013 15:05, Avnesh Shakya <avnesh.nitk at gmail.com> wrote:
> | but when I m using like
> |
> | import random
> | a = random.randrange(0, 59)
> | */a * * * * bash /home/avin/cronJob/test.sh
> | then it's showing error becose of varable 'a', so now how can i take
> | variable?

You put that into your crontab? I do not think this means what you
think it means; cron does not execute arbitrary Python code.

> - randrange() is like other python ranges: it does not include the end value.
>   So your call picks a number from 0..58, not 0..59.
>   Say randrange(0,60). Think "start, length".

Nitpick: It's not start, length; it's start, stop-before. If the start
is 10 and the second argument is 20, you'll get numbers from 10 to 19.
But your conclusion is still accurate :)

ChrisA
(two Princess Bride references in as many threads, doing well!)


From cs at zip.com.au  Tue May 21 06:32:39 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Tue, 21 May 2013 20:32:39 +1000
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <CAPTjJmp4VWi_e-TmyvB=o05jfFRB=hE7FzJLm-XjGBJaZBjXmw@mail.gmail.com>
References: <CAPTjJmp4VWi_e-TmyvB=o05jfFRB=hE7FzJLm-XjGBJaZBjXmw@mail.gmail.com>
Message-ID: <20130521103239.GA24261@cskk.homeip.net>

On 21May2013 17:56, Chris Angelico <rosuav at gmail.com> wrote:
| On Tue, May 21, 2013 at 11:12 AM, Cameron Simpson <cs at zip.com.au> wrote:
| > - randrange() is like other python ranges: it does not include the end value.
| >   So your call picks a number from 0..58, not 0..59.
| >   Say randrange(0,60). Think "start, length".
| 
| Nitpick: It's not start, length; it's start, stop-before. If the start
| is 10 and the second argument is 20, you'll get numbers from 10 to 19.
| But your conclusion is still accurate :)

But it's still a useful thing to think when you're trying to reason
about ranges unless you're doing something unusual.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Life IS pain, highness...  anyone who tries to tell you different is
trying to sell you something.   - Wesley, The_Princess_Bride


From davea at davea.name  Tue May 21 09:54:06 2013
From: davea at davea.name (Dave Angel)
Date: Tue, 21 May 2013 09:54:06 -0400
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <20130521103239.GA24261@cskk.homeip.net>
References: <CAPTjJmp4VWi_e-TmyvB=o05jfFRB=hE7FzJLm-XjGBJaZBjXmw@mail.gmail.com>
	<20130521103239.GA24261@cskk.homeip.net>
Message-ID: <519B7C7E.1010002@davea.name>

On 05/21/2013 06:32 AM, Cameron Simpson wrote:
> On 21May2013 17:56, Chris Angelico <rosuav at gmail.com> wrote:
> | On Tue, May 21, 2013 at 11:12 AM, Cameron Simpson <cs at zip.com.au> wrote:
> | > - randrange() is like other python ranges: it does not include the end value.
> | >   So your call picks a number from 0..58, not 0..59.
> | >   Say randrange(0,60). Think "start, length".
> |
> | Nitpick: It's not start, length; it's start, stop-before. If the start
> | is 10 and the second argument is 20, you'll get numbers from 10 to 19.
> | But your conclusion is still accurate :)
>
> But it's still a useful thing to think when you're trying to reason
> about ranges unless you're doing something unusual.
>


No, it's only happens to look like length when start is zero.  So as a 
mnemonic, it's highly misleading.


-- 
DaveA


From cs at zip.com.au  Tue May 21 23:00:23 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Wed, 22 May 2013 13:00:23 +1000
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <519B7C7E.1010002@davea.name>
References: <519B7C7E.1010002@davea.name>
Message-ID: <20130522030023.GA53359@cskk.homeip.net>

On 21May2013 09:54, Dave Angel <davea at davea.name> wrote:
| On 05/21/2013 06:32 AM, Cameron Simpson wrote:
| >On 21May2013 17:56, Chris Angelico <rosuav at gmail.com> wrote:
| >| On Tue, May 21, 2013 at 11:12 AM, Cameron Simpson <cs at zip.com.au> wrote:
| >| > - randrange() is like other python ranges: it does not include the end value.
| >| >   So your call picks a number from 0..58, not 0..59.
| >| >   Say randrange(0,60). Think "start, length".
| >|
| >| Nitpick: It's not start, length; it's start, stop-before. If the start
| >| is 10 and the second argument is 20, you'll get numbers from 10 to 19.
| >| But your conclusion is still accurate :)
| >
| >But it's still a useful thing to think when you're trying to reason
| >about ranges unless you're doing something unusual.
| 
| No, it's only happens to look like length when start is zero.  So as
| a mnemonic, it's highly misleading.

Feh! No self respecting computer scientist would ever count from
other than zero!

Actually, yes, you're right there.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Q: How does a hacker fix a function which doesn't work for all of the elements in its domain?
A: He changes the domain.


From jpiitula at ling.helsinki.fi  Tue May 21 04:21:39 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 21 May 2013 11:21:39 +0300
Subject: How to run a python script twice randomly in a day?
References: <CAEA17E+UpccfENQJEZv_Pp+5P00PUnhHvdztZ0ofMJZF67fdVA@mail.gmail.com>
	<20130521011220.GA62488@cskk.homeip.net>
	<mailman.1908.1369122996.3114.python-list@python.org>
Message-ID: <qotwqqsrbe4.fsf@ruuvi.it.helsinki.fi>

Chris Angelico writes:

> > On 20May2013 15:05, Avnesh Shakya wrote:
> >   So your call picks a number from 0..58, not 0..59.
> >   Say randrange(0,60). Think "start, length".
> 
> Nitpick: It's not start, length; it's start, stop-before. If the
> start is 10 and the second argument is 20, you'll get numbers from
> 10 to 19.  But your conclusion is still accurate :)

I've sometimes named the latter index "past", as in just past the
range. I'm also happy to call it just "end". The inclusive-style names
might be "first" and "last", so "past" is "last + 1".

The length of the range from "start" to "end" is "end - start" without
a "pest" term that is either -1 or +1 though I forget which; two
consecutive ranges are from b to m, then from m to e; an empty range
is from b to b.


From rosuav at gmail.com  Tue May 21 05:18:25 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 21 May 2013 19:18:25 +1000
Subject: How to run a python script twice randomly in a day?
In-Reply-To: <qotwqqsrbe4.fsf@ruuvi.it.helsinki.fi>
References: <CAEA17E+UpccfENQJEZv_Pp+5P00PUnhHvdztZ0ofMJZF67fdVA@mail.gmail.com>
	<20130521011220.GA62488@cskk.homeip.net>
	<mailman.1908.1369122996.3114.python-list@python.org>
	<qotwqqsrbe4.fsf@ruuvi.it.helsinki.fi>
Message-ID: <CAPTjJmqbAwwe1oGy-b4to0CtMFh-VA9AUB4yCpk7SbXNSusN8w@mail.gmail.com>

On Tue, May 21, 2013 at 6:21 PM, Jussi Piitulainen
<jpiitula at ling.helsinki.fi> wrote:
> Chris Angelico writes:
>
>> > On 20May2013 15:05, Avnesh Shakya wrote:
>> >   So your call picks a number from 0..58, not 0..59.
>> >   Say randrange(0,60). Think "start, length".
>>
>> Nitpick: It's not start, length; it's start, stop-before. If the
>> start is 10 and the second argument is 20, you'll get numbers from
>> 10 to 19.  But your conclusion is still accurate :)
>
> I've sometimes named the latter index "past", as in just past the
> range. I'm also happy to call it just "end". The inclusive-style names
> might be "first" and "last", so "past" is "last + 1".
>
> The length of the range from "start" to "end" is "end - start" without
> a "pest" term that is either -1 or +1 though I forget which; two
> consecutive ranges are from b to m, then from m to e; an empty range
> is from b to b.

Agreed. The inclusive-exclusive range is by far the most useful.
There's unfortunately a massive case of lock-in here, but Scripture
references would be ever so much more convenient as inc-exc. For
instance, today in family devotions we read Galatians 2:1 - 2:21. At a
glance, do you know whether that's the entire chapter? What if it were
written as Galatians 2 to Galatians 3? Simple!

ChrisA


From frank at chagford.com  Mon May 20 03:05:48 2013
From: frank at chagford.com (Frank Millman)
Date: Mon, 20 May 2013 09:05:48 +0200
Subject: Question about ast.literal_eval
Message-ID: <knci07$jol$1@ger.gmane.org>

Hi all

I am trying to emulate a SQL check constraint in Python. Quoting from 
the PostgreSQL docs, "A check constraint is the most generic constraint 
type. It allows you to specify that the value in a certain column must 
satisfy a Boolean (truth-value) expression."

The problem is that I want to store the constraint as a string, and I 
was hoping to use ast.literal_eval to evaluate it, but it does not work.

 >>> x = 'abc'
 >>> x in ('abc', xyz')
True
 >>> b = "x in ('abc', 'xyz')"
 >>> eval(b)
True
 >>> from ast import literal_eval
 >>> literal_eval(b)
ValueError: malformed node or string: <_ast.Compare object at ...>

Is there a safe way to do what I want? I am using python 3.3.

Thanks

Frank Millman



From carlosnepomuceno at outlook.com  Mon May 20 03:34:47 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 20 May 2013 10:34:47 +0300
Subject: Question about ast.literal_eval
In-Reply-To: <knci07$jol$1@ger.gmane.org>
References: <knci07$jol$1@ger.gmane.org>
Message-ID: <BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>

It seems to me you can't use ast.literal_eval()[1] to evaluate that kind of expression because it's just for literals[2].

Why don't you use eval()?


[1] http://docs.python.org/2/library/ast.html#ast-helpers

[2] http://docs.python.org/2/reference/lexical_analysis.html#literals

----------------------------------------
> To: python-list at python.org
> From: frank at chagford.com
> Subject: Question about ast.literal_eval
> Date: Mon, 20 May 2013 09:05:48 +0200
>
> Hi all
>
> I am trying to emulate a SQL check constraint in Python. Quoting from
> the PostgreSQL docs, "A check constraint is the most generic constraint
> type. It allows you to specify that the value in a certain column must
> satisfy a Boolean (truth-value) expression."
>
> The problem is that I want to store the constraint as a string, and I
> was hoping to use ast.literal_eval to evaluate it, but it does not work.
>
>>>> x = 'abc'
>>>> x in ('abc', xyz')
> True
>>>> b = "x in ('abc', 'xyz')"
>>>> eval(b)
> True
>>>> from ast import literal_eval
>>>> literal_eval(b)
> ValueError: malformed node or string: <_ast.Compare object at ...>
>
> Is there a safe way to do what I want? I am using python 3.3.
>
> Thanks
>
> Frank Millman
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From frank at chagford.com  Mon May 20 03:50:02 2013
From: frank at chagford.com (Frank Millman)
Date: Mon, 20 May 2013 09:50:02 +0200
Subject: Question about ast.literal_eval
In-Reply-To: <BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
Message-ID: <knckj0$cft$1@ger.gmane.org>

[Corrected top-posting]

 >> To: python-list at python.org
>> From: frank at chagford.com
>> Subject: Question about ast.literal_eval
>> Date: Mon, 20 May 2013 09:05:48 +0200
>>
>> Hi all
>>
>> I am trying to emulate a SQL check constraint in Python. Quoting from
>> the PostgreSQL docs, "A check constraint is the most generic constraint
>> type. It allows you to specify that the value in a certain column must
>> satisfy a Boolean (truth-value) expression."
>>
>> The problem is that I want to store the constraint as a string, and I
>> was hoping to use ast.literal_eval to evaluate it, but it does not work.
>>

On 20/05/2013 09:34, Carlos Nepomuceno wrote:

> It seems to me you can't use ast.literal_eval()[1] to evaluate that kind of expression
 > because it's just for literals[2].
>
> Why don't you use eval()?
>

Because users can create their own columns, with their own constraints. 
Therefore the string is user-modifiable, so it cannot be trusted.

Frank




From rosuav at gmail.com  Mon May 20 03:55:03 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 20 May 2013 17:55:03 +1000
Subject: Question about ast.literal_eval
In-Reply-To: <knckj0$cft$1@ger.gmane.org>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
Message-ID: <CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>

On Mon, May 20, 2013 at 5:50 PM, Frank Millman <frank at chagford.com> wrote:
> On 20/05/2013 09:34, Carlos Nepomuceno wrote:
>> Why don't you use eval()?
>>
>
> Because users can create their own columns, with their own constraints.
> Therefore the string is user-modifiable, so it cannot be trusted.

Plenty of reason right there :)

Is it a requirement that they be able to key in a constraint as a
single string? We have a similar situation in one of the systems at
work, so we divided the input into three(ish) parts: pick a field,
pick an operator (legal operators vary according to field type -
integers can't be compared against regular expressions, timestamps can
use >= and < only), then enter the other operand. Sure, that cuts out
a few possibilities, but you get 99.9%+ of all usage and it's easy to
sanitize.

ChrisA


From frank at chagford.com  Mon May 20 04:07:43 2013
From: frank at chagford.com (Frank Millman)
Date: Mon, 20 May 2013 10:07:43 +0200
Subject: Question about ast.literal_eval
In-Reply-To: <CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
Message-ID: <knclk6$lva$1@ger.gmane.org>

On 20/05/2013 09:55, Chris Angelico wrote:
> On Mon, May 20, 2013 at 5:50 PM, Frank Millman <frank at chagford.com> wrote:
>> On 20/05/2013 09:34, Carlos Nepomuceno wrote:
>>> Why don't you use eval()?
>>>
>>
>> Because users can create their own columns, with their own constraints.
>> Therefore the string is user-modifiable, so it cannot be trusted.
>
> Plenty of reason right there :)
>
> Is it a requirement that they be able to key in a constraint as a
> single string? We have a similar situation in one of the systems at
> work, so we divided the input into three(ish) parts: pick a field,
> pick an operator (legal operators vary according to field type -
> integers can't be compared against regular expressions, timestamps can
> use >= and < only), then enter the other operand. Sure, that cuts out
> a few possibilities, but you get 99.9%+ of all usage and it's easy to
> sanitize.
>
> ChrisA
>

It is not a requirement, no. I just thought it would be a convenient 
short-cut.

I had in mind something similar to your scheme above, so I guess I will 
have to bite the bullet and implement it.

Thanks

Frank




From frank at chagford.com  Mon May 20 09:26:02 2013
From: frank at chagford.com (Frank Millman)
Date: Mon, 20 May 2013 15:26:02 +0200
Subject: Question about ast.literal_eval
In-Reply-To: <knclk6$lva$1@ger.gmane.org>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org>
Message-ID: <knd88q$mo9$1@ger.gmane.org>

On 20/05/2013 10:07, Frank Millman wrote:
> On 20/05/2013 09:55, Chris Angelico wrote:
>> Is it a requirement that they be able to key in a constraint as a
>> single string? We have a similar situation in one of the systems at
>> work, so we divided the input into three(ish) parts: pick a field,
>> pick an operator (legal operators vary according to field type -
>> integers can't be compared against regular expressions, timestamps can
>> use >= and < only), then enter the other operand. Sure, that cuts out
>> a few possibilities, but you get 99.9%+ of all usage and it's easy to
>> sanitize.
>>
>> ChrisA
>>
>
> It is not a requirement, no. I just thought it would be a convenient
> short-cut.
>
> I had in mind something similar to your scheme above, so I guess I will
> have to bite the bullet and implement it.
>

Can anyone see anything wrong with the following approach. I have not 
definitely decided to do it this way, but I have been experimenting and 
it seems to work.

I store the boolean test as a json'd list of 6-part tuples. Each element 
of the tuple is a string, defined as follows -

0 - for the first entry in the list, the word 'check' (a placeholder - 
it is discarded at evaluation time), for any subsequent entries the word 
'and' or 'or'.

1 - left bracket - either '(' or ''.

2 - column name to check - it will be validated on entry.

3 - operator - must be one of '=', '!=', '<', '>', '<=', '>=', 'in', 
'is', 'is not'. At evaluation time, '=' is changed to '=='.

4 - value to compare - at evaluation time I call 
str(literal_eval(value)) to ensure that it is safe.

5 - right bracket - either ')' or ''.

At evaluation time I loop through the list, construct the boolean test 
as a string, and call eval() on it.

Here are some examples -

check = []
check.append(('check', '', 'name', 'in', "('abc', 'xyz')", ''))

check = []
check.append(('check', '', 'value', '>=', '0', ''))

check = []
check.append(('check', '(', 'descr', 'is not', 'None', ''))
check.append(('and', '', 'alt', 'is', 'None', ')'))
check.append(('or', '(', 'descr', 'is', 'None', ''))
check.append(('and', '', 'alt', 'is not', 'None', ')'))

I don't plan to check the logic - I will just display the exception if 
it does not evaluate.

It seems safe to me. Can anyone see a problem with it?

Frank




From rosuav at gmail.com  Mon May 20 12:13:47 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 21 May 2013 02:13:47 +1000
Subject: Question about ast.literal_eval
In-Reply-To: <knd88q$mo9$1@ger.gmane.org>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org> <knd88q$mo9$1@ger.gmane.org>
Message-ID: <CAPTjJmqiuKrnsfMgJLn5SZbJ=GuErfb=LdJGPB_kQYyT+KSw_g@mail.gmail.com>

On Mon, May 20, 2013 at 11:26 PM, Frank Millman <frank at chagford.com> wrote:
> 0 - for the first entry in the list, the word 'check' (a placeholder - it is
> discarded at evaluation time), for any subsequent entries the word 'and' or
> 'or'.
>
> 1 - left bracket - either '(' or ''.
>
> 5 - right bracket - either ')' or ''.

I think what you have is safe, but extremely complicated to work with.
Six separate pieces, and things have to be in the right slots... I
think you've spent too many "complexity points" on the above three
components, and you're getting too little return for them. What
happens if the nesting is mucked up? Could get verrry messy to check.

Combining multiple conditions with a mixture of ands and ors is a
nightmare to try to explain (unless you just point to the Python docs,
which IMO costs you even more complexity points); the only safe option
is to parenthesize everything. The system I pushed for at work (which
was finally approved and implemented a few months ago) is more or less
this: conditions are grouped together into blocks; for each group, you
can choose whether it's "all" or "any" (aka and/or), and you choose
whether the overall result is all-groups or any-group. That still
costs a few complexity points (and, btw, our *actual* implementation
is a bit more complicated than that, but I think we could cut it down
to what I just described here without loss of functionality), but it
gives the bulk of what people will actually want without the
complexities of point-and-click code.

The downside of that sort of system is that it requires a two-level
tree. On the flip side, that's often how people will be thinking about
their conditions anyway (eg using a pair of conditions ">" and "<" to
implement a range check - conceptually it's a single check), so that
won't cost too much.

ChrisA


From frank at chagford.com  Tue May 21 02:46:08 2013
From: frank at chagford.com (Frank Millman)
Date: Tue, 21 May 2013 08:46:08 +0200
Subject: Question about ast.literal_eval
In-Reply-To: <CAPTjJmqiuKrnsfMgJLn5SZbJ=GuErfb=LdJGPB_kQYyT+KSw_g@mail.gmail.com>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org> <knd88q$mo9$1@ger.gmane.org>
	<CAPTjJmqiuKrnsfMgJLn5SZbJ=GuErfb=LdJGPB_kQYyT+KSw_g@mail.gmail.com>
Message-ID: <knf57c$en5$1@ger.gmane.org>

On 20/05/2013 18:13, Chris Angelico wrote:
> On Mon, May 20, 2013 at 11:26 PM, Frank Millman <frank at chagford.com> wrote:
>> 0 - for the first entry in the list, the word 'check' (a placeholder - it is
>> discarded at evaluation time), for any subsequent entries the word 'and' or
>> 'or'.
>>
>> 1 - left bracket - either '(' or ''.
>>
>> 5 - right bracket - either ')' or ''.
>
> I think what you have is safe, but extremely complicated to work with.
> Six separate pieces, and things have to be in the right slots... I
> think you've spent too many "complexity points" on the above three
> components, and you're getting too little return for them. What
> happens if the nesting is mucked up? Could get verrry messy to check.
>
> Combining multiple conditions with a mixture of ands and ors is a
> nightmare to try to explain (unless you just point to the Python docs,
> which IMO costs you even more complexity points); the only safe option
> is to parenthesize everything. The system I pushed for at work (which
> was finally approved and implemented a few months ago) is more or less
> this: conditions are grouped together into blocks; for each group, you
> can choose whether it's "all" or "any" (aka and/or), and you choose
> whether the overall result is all-groups or any-group. That still
> costs a few complexity points (and, btw, our *actual* implementation
> is a bit more complicated than that, but I think we could cut it down
> to what I just described here without loss of functionality), but it
> gives the bulk of what people will actually want without the
> complexities of point-and-click code.
>
> The downside of that sort of system is that it requires a two-level
> tree. On the flip side, that's often how people will be thinking about
> their conditions anyway (eg using a pair of conditions ">" and "<" to
> implement a range check - conceptually it's a single check), so that
> won't cost too much.
>

You may be right, Chris, but I don't think my approach is all that bad.

The vast majority of tests will be simple - either a single line, or two 
lines for a range check, with no brackets at all.

If the requirement is more complicated than that, well, I don't think 
the complication can be avoided, and at least this approach gives full 
control.

FWIW, I use the same approach to allow users to construct their own 
WHERE clauses in custom views. Again, the vast majority are simple, but 
there are times when it can get complicated.

The proof of the pudding will be when I try to get ordinary users to get 
their own hands dirty - I am not there yet. If I ever get this released, 
the business model will be free software, but support will be charged 
for. So if a user gets out of his/her depth, there will be assistance 
available.

Time will tell who is right ... ;-)

Frank




From rosuav at gmail.com  Tue May 21 03:35:40 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 21 May 2013 17:35:40 +1000
Subject: Question about ast.literal_eval
In-Reply-To: <knf57c$en5$1@ger.gmane.org>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org> <knd88q$mo9$1@ger.gmane.org>
	<CAPTjJmqiuKrnsfMgJLn5SZbJ=GuErfb=LdJGPB_kQYyT+KSw_g@mail.gmail.com>
	<knf57c$en5$1@ger.gmane.org>
Message-ID: <CAPTjJmoATa8yudb6gPqvEwwqdF8Z8bDVbh47zXjz+FQ6rSOu-A@mail.gmail.com>

On Tue, May 21, 2013 at 4:46 PM, Frank Millman <frank at chagford.com> wrote:
> You may be right, Chris, but I don't think my approach is all that bad.

Frankly, I'm not altogether convinced that our approach is right
either :) But like the Oracle in the Matrix, I'm not here to push you
to one decision or another so much as to just put the options in front
of you and let you make up your own <bowdlerized> mind. Except in a
few cases where I'm really certain of my ground (like "don't put any
untrusted data through eval()"...).

> The vast majority of tests will be simple - either a single line, or two
> lines for a range check, with no brackets at all.
>
> If the requirement is more complicated than that, well, I don't think the
> complication can be avoided, and at least this approach gives full control.

Yeah, and this is where the issue of complexity points comes in.
You're spending a lot of them on functionality that most users won't
even use, and those who do will use only occasionally. You're forcing
them to match their brackets (not just have the same number of each
type, but also to get the nesting correct), and according to your
current spec, there can be no more than one open/close bracket at each
condition, so they'll have to arbitrarily add dummy conditions to make
certain forms of nesting work. You're exposing a lot of the underlying
interpreter, while forcing the user to dance wearing a body cast.
Sure, it can work, but it's unnecessarily hard.

> FWIW, I use the same approach to allow users to construct their own WHERE
> clauses in custom views. Again, the vast majority are simple, but there are
> times when it can get complicated.

Our alpha system is actually online, and we have exactly that system -
a query builder that renders down to a WHERE clause. If you're
curious, message me offline and I'll give you the URL.

> The proof of the pudding will be when I try to get ordinary users to get
> their own hands dirty - I am not there yet. If I ever get this released, the
> business model will be free software, but support will be charged for. So if
> a user gets out of his/her depth, there will be assistance available.
>
> Time will tell who is right ... ;-)

Who is right, and who is dead. Hey, are you aware that both Steven and
I come from Australia, and that we are used to having people not trust
us? Truly, you have a dizzying intellect!

ChrisA
... couldn't resist...


From steve+comp.lang.python at pearwood.info  Mon May 20 12:12:27 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 20 May 2013 16:12:27 GMT
Subject: Question about ast.literal_eval
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org>
	<mailman.1888.1369056365.3114.python-list@python.org>
Message-ID: <519a4b6a$0$29997$c3e8da3$5496439d@news.astraweb.com>

On Mon, 20 May 2013 15:26:02 +0200, Frank Millman wrote:

> Can anyone see anything wrong with the following approach. I have not
> definitely decided to do it this way, but I have been experimenting and
> it seems to work.
> 
> I store the boolean test as a json'd list of 6-part tuples. Each element
> of the tuple is a string, defined as follows -
> 
> 0 - for the first entry in the list, the word 'check' (a placeholder -
> it is discarded at evaluation time), for any subsequent entries the word
> 'and' or 'or'.
> 
> 1 - left bracket - either '(' or ''.
> 
> 2 - column name to check - it will be validated on entry.
> 
> 3 - operator - must be one of '=', '!=', '<', '>', '<=', '>=', 'in',
> 'is', 'is not'. At evaluation time, '=' is changed to '=='.
> 
> 4 - value to compare - at evaluation time I call
> str(literal_eval(value)) to ensure that it is safe.
> 
> 5 - right bracket - either ')' or ''.
> 
> At evaluation time I loop through the list, construct the boolean test
> as a string, and call eval() on it.
[...]
> It seems safe to me. Can anyone see a problem with it?


It seems safe to me too, but then any fool can come up with a system 
which they themselves cannot break :-)

I think the real worry is validating the column name. That will be 
critical. Personally, I would strongly suggest writing your own mini-
evaluator that walks the list and evaluates it by hand. It isn't as 
convenient as just calling eval, but *definitely* safer.

If you do call eval, make sure you supply the globals and locals 
arguments. The usual way is:

eval(expression, {'__builtins__': None}, {})

which gives you an empty locals() and a minimal, (mostly) safe globals.

Finally, as a "belt-and-braces" approach, I wouldn't even call eval 
directly, but call a thin wrapper that raises an exception if the 
expression contains an underscore. Underscores are usually the key to 
breaking eval, so refusing to evaluate anything with an underscore raises 
the barrier very high.

And even with all those defences, I wouldn't allow untrusted data from 
the Internet anywhere near this. Just because I can't break it, doesn't 
mean it's safe.


-- 
Steven


From rosuav at gmail.com  Mon May 20 12:23:19 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 21 May 2013 02:23:19 +1000
Subject: Question about ast.literal_eval
In-Reply-To: <519a4b6a$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org>
	<mailman.1888.1369056365.3114.python-list@python.org>
	<519a4b6a$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmr_-Dp5zh=_5i6t+5F1GHLkoAx3KLxHue7Mp+shi88-7A@mail.gmail.com>

On Tue, May 21, 2013 at 2:12 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Personally, I would strongly suggest writing your own mini-
> evaluator that walks the list and evaluates it by hand. It isn't as
> convenient as just calling eval, but *definitely* safer.

Probably faster, too, for what it's worth - eval is pretty expensive.

ChrisA


From frank at chagford.com  Tue May 21 02:30:03 2013
From: frank at chagford.com (Frank Millman)
Date: Tue, 21 May 2013 08:30:03 +0200
Subject: Question about ast.literal_eval
In-Reply-To: <519a4b6a$0$29997$c3e8da3$5496439d@news.astraweb.com>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org>
	<mailman.1888.1369056365.3114.python-list@python.org>
	<519a4b6a$0$29997$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <knf497$65d$1@ger.gmane.org>

On 20/05/2013 18:12, Steven D'Aprano wrote:
> On Mon, 20 May 2013 15:26:02 +0200, Frank Millman wrote:
>
>> Can anyone see anything wrong with the following approach. I have not
>> definitely decided to do it this way, but I have been experimenting and
>> it seems to work.
>>
[...]
>
> It seems safe to me too, but then any fool can come up with a system
> which they themselves cannot break :-)
>

Thanks for the detailed response.

> I think the real worry is validating the column name. That will be
> critical.

I would not pass the actual column name to eval(), I would use it to 
retrieve a value from a data object and pass that to eval(). However, 
then your point becomes 'validating the value retrieved'. I had not 
thought about that. I will investigate further.

> Personally, I would strongly suggest writing your own mini-
> evaluator that walks the list and evaluates it by hand. It isn't as
> convenient as just calling eval, but *definitely* safer.
>

I am not sure I can wrap my mind around mixed 'and's, 'or's, and brackets.

[Thinking aloud]
Maybe I can manually reduce each internal test to a True or False, 
substitute them in the list, and then call eval() on the result.

eval('(True and False) or (False or True)')

I will experiment with that.

> If you do call eval, make sure you supply the globals and locals
> arguments. The usual way is:
>
> eval(expression, {'__builtins__': None}, {})
>
> which gives you an empty locals() and a minimal, (mostly) safe globals.
>

Thanks - I did not know about that.

> Finally, as a "belt-and-braces" approach, I wouldn't even call eval
> directly, but call a thin wrapper that raises an exception if the
> expression contains an underscore. Underscores are usually the key to
> breaking eval, so refusing to evaluate anything with an underscore raises
> the barrier very high.
>
> And even with all those defences, I wouldn't allow untrusted data from
> the Internet anywhere near this. Just because I can't break it, doesn't
> mean it's safe.
>

All good advice - much appreciated.

Frank




From steve+comp.lang.python at pearwood.info  Tue May 21 03:21:58 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 21 May 2013 07:21:58 GMT
Subject: Question about ast.literal_eval
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org>
	<mailman.1888.1369056365.3114.python-list@python.org>
	<519a4b6a$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1905.1369117820.3114.python-list@python.org>
Message-ID: <519b2096$0$6574$c3e8da3$5496439d@news.astraweb.com>

On Tue, 21 May 2013 08:30:03 +0200, Frank Millman wrote:

> On 20/05/2013 18:12, Steven D'Aprano wrote:

>> Personally, I would strongly suggest writing your own mini- evaluator
>> that walks the list and evaluates it by hand. It isn't as convenient as
>> just calling eval, but *definitely* safer.
>>
>>
> I am not sure I can wrap my mind around mixed 'and's, 'or's, and
> brackets.


Parsers are a solved problem in computer science, he says as if he had a 
clue what he was talking about *wink*

Here's a sketch of a solution... suppose you have a sequence of records, 
looking like this:

(bool_op, column_name, comparison_op, literal)

with appropriate validation on each field. The very first record has 
bool_op set to "or". Then, you do something like this:


import operator
OPERATORS = {
    '=': operator.eq,
    'is': operator.is_,
    '<': operator.lt,
    # etc.
    }


def eval_op(column_name, op, literal):
    value = lookup(column_name)  # whatever...
    return OPERATORS[op](value, literal)

result = False

for (bool_op, column_name, comparison_op, literal) in sequence:
    flag = eval_op(column_name, comparison_op, literal)
    if bool_op == 'and':
        result = result and flag
    else: 
        assert bool_op == 'or'
        result = result or flag
    # Lazy processing?
    if result:
        break


and in theory it should all Just Work.




-- 
Steven


From frank at chagford.com  Tue May 21 04:06:35 2013
From: frank at chagford.com (Frank Millman)
Date: Tue, 21 May 2013 10:06:35 +0200
Subject: Question about ast.literal_eval
In-Reply-To: <519b2096$0$6574$c3e8da3$5496439d@news.astraweb.com>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org>
	<mailman.1888.1369056365.3114.python-list@python.org>
	<519a4b6a$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1905.1369117820.3114.python-list@python.org>
	<519b2096$0$6574$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <knf9u3$rr0$1@ger.gmane.org>

On 21/05/2013 09:21, Steven D'Aprano wrote:
> On Tue, 21 May 2013 08:30:03 +0200, Frank Millman wrote:
>
>> I am not sure I can wrap my mind around mixed 'and's, 'or's, and
>> brackets.
>
> Parsers are a solved problem in computer science, he says as if he had a
> clue what he was talking about *wink*
>
> Here's a sketch of a solution... suppose you have a sequence of records,
> looking like this:
>
> (bool_op, column_name, comparison_op, literal)
>
> with appropriate validation on each field. The very first record has
> bool_op set to "or". Then, you do something like this:
>
> import operator
> OPERATORS = {
>      '=': operator.eq,
>      'is': operator.is_,
>      '<': operator.lt,
>      # etc.
>      }
>
> def eval_op(column_name, op, literal):
>      value = lookup(column_name)  # whatever...
>      return OPERATORS[op](value, literal)
>
> result = False
>
> for (bool_op, column_name, comparison_op, literal) in sequence:
>      flag = eval_op(column_name, comparison_op, literal)
>      if bool_op == 'and':
>          result = result and flag
>      else:
>          assert bool_op == 'or'
>          result = result or flag
>      # Lazy processing?
>      if result:
>          break
>
> and in theory it should all Just Work.

That's very clever - thanks, Steven.

It doesn't address the issue of brackets. I imagine that the answer is 
something like -

   maintain a stack of results
   for each left bracket, push a level
   for each right bracket, pop the result

or something ...

I am sure that with enough trial and error I can get it working, but I 
might cheat for now and use the trick I mentioned earlier of calling 
eval() on a sequence of manually derived True/False values. I really 
can't see anything going wrong with that.

BTW, thanks to ChrisA for the following tip -

import operator
ops = {
   'in':lambda x,y: x in y,  # operator.contains has the args backwards

I would have battled with that one.

Frank




From fabiosantosart at gmail.com  Tue May 21 04:23:16 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 21 May 2013 09:23:16 +0100
Subject: Question about ast.literal_eval
In-Reply-To: <knf9u3$rr0$1@ger.gmane.org>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org>
	<mailman.1888.1369056365.3114.python-list@python.org>
	<519a4b6a$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1905.1369117820.3114.python-list@python.org>
	<519b2096$0$6574$c3e8da3$5496439d@news.astraweb.com>
	<knf9u3$rr0$1@ger.gmane.org>
Message-ID: <CAA=1kxRdVJYVD8CGrmJ-033P7yGiRzvZTaXC-wZ-CY8axA3=2Q@mail.gmail.com>

On 21 May 2013 09:10, "Frank Millman" <frank at chagford.com> wrote:
> It doesn't address the issue of brackets. I imagine that the answer is
something like -
>
>   maintain a stack of results
>   for each left bracket, push a level
>   for each right bracket, pop the result
>
> or something ...
>

Time for me to suggest pyparsing or PLY. You're better off creating your
own AST and walking it to produce python or SQL than reinventing the wheel,
I think.
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From breamoreboy at yahoo.co.uk  Tue May 21 05:00:48 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 21 May 2013 10:00:48 +0100
Subject: Question about ast.literal_eval
In-Reply-To: <CAA=1kxRdVJYVD8CGrmJ-033P7yGiRzvZTaXC-wZ-CY8axA3=2Q@mail.gmail.com>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<CAPTjJmpb073XFH5ksNhzRyAJNSJF=6WNq5pGzed4PXqBrJBN=A@mail.gmail.com>
	<knclk6$lva$1@ger.gmane.org>
	<mailman.1888.1369056365.3114.python-list@python.org>
	<519a4b6a$0$29997$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1905.1369117820.3114.python-list@python.org>
	<519b2096$0$6574$c3e8da3$5496439d@news.astraweb.com>
	<knf9u3$rr0$1@ger.gmane.org>
	<CAA=1kxRdVJYVD8CGrmJ-033P7yGiRzvZTaXC-wZ-CY8axA3=2Q@mail.gmail.com>
Message-ID: <knfd33$qs1$1@ger.gmane.org>

On 21/05/2013 09:23, F?bio Santos wrote:
>
> On 21 May 2013 09:10, "Frank Millman" <frank at chagford.com
> <mailto:frank at chagford.com>> wrote:
>  > It doesn't address the issue of brackets. I imagine that the answer
> is something like -
>  >
>  >   maintain a stack of results
>  >   for each left bracket, push a level
>  >   for each right bracket, pop the result
>  >
>  > or something ...
>  >
>
> Time for me to suggest pyparsing or PLY. You're better off creating your
> own AST and walking it to produce python or SQL than reinventing the
> wheel, I think.
>

Or pick one from this lot http://nedbatchelder.com/text/python-parsers.html

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From carlosnepomuceno at outlook.com  Mon May 20 03:55:35 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 20 May 2013 10:55:35 +0300
Subject: Question about ast.literal_eval
In-Reply-To: <knckj0$cft$1@ger.gmane.org>
References: <knci07$jol$1@ger.gmane.org>,
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>,
	<knckj0$cft$1@ger.gmane.org>
Message-ID: <BLU176-W35D12CEB38B7D64744E8FBD7AF0@phx.gbl>

----------------------------------------
> To: python-list at python.org
> From: frank at chagford.com
> Subject: Re: Question about ast.literal_eval
> Date: Mon, 20 May 2013 09:50:02 +0200
>
> [Corrected top-posting]
>
>>> To: python-list at python.org
>>> From: frank at chagford.com
>>> Subject: Question about ast.literal_eval
>>> Date: Mon, 20 May 2013 09:05:48 +0200
>>>
>>> Hi all
>>>
>>> I am trying to emulate a SQL check constraint in Python. Quoting from
>>> the PostgreSQL docs, "A check constraint is the most generic constraint
>>> type. It allows you to specify that the value in a certain column must
>>> satisfy a Boolean (truth-value) expression."
>>>
>>> The problem is that I want to store the constraint as a string, and I
>>> was hoping to use ast.literal_eval to evaluate it, but it does not work.
>>>
>
> On 20/05/2013 09:34, Carlos Nepomuceno wrote:
>
>> It seems to me you can't use ast.literal_eval()[1] to evaluate that kind of expression
>> because it's just for literals[2].
>>
>> Why don't you use eval()?
>>
>
> Because users can create their own columns, with their own constraints.
> Therefore the string is user-modifiable, so it cannot be trusted.

I understand your motivation but I don't know what protection ast.literal_eval() is offering that eval() doesn't.

> Frank
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rosuav at gmail.com  Mon May 20 04:13:18 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 20 May 2013 18:13:18 +1000
Subject: Question about ast.literal_eval
In-Reply-To: <BLU176-W35D12CEB38B7D64744E8FBD7AF0@phx.gbl>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<BLU176-W35D12CEB38B7D64744E8FBD7AF0@phx.gbl>
Message-ID: <CAPTjJmrD9AOXWb+PwtNTShKbzwFpy0bVwnMdRfVfYGQ9P=LeeA@mail.gmail.com>

On Mon, May 20, 2013 at 5:55 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> I understand your motivation but I don't know what protection ast.literal_eval() is offering that eval() doesn't.

eval will *execute code*, while literal_eval will not. That's the
protection. With ast.literal_eval, all that can happen is that it
produces a single result value. In this case, unfortunately, that's
insufficient; a comparison needs to be done, ergo it's not an entire
literal. But something else in the ast module may be able to serve, or
maybe literal_eval can do the bulk of the work.

ChrisA


From frank at chagford.com  Mon May 20 04:15:49 2013
From: frank at chagford.com (Frank Millman)
Date: Mon, 20 May 2013 10:15:49 +0200
Subject: Question about ast.literal_eval
In-Reply-To: <BLU176-W35D12CEB38B7D64744E8FBD7AF0@phx.gbl>
References: <knci07$jol$1@ger.gmane.org>,
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>,
	<knckj0$cft$1@ger.gmane.org>
	<BLU176-W35D12CEB38B7D64744E8FBD7AF0@phx.gbl>
Message-ID: <kncm3b$p2j$1@ger.gmane.org>

On 20/05/2013 09:55, Carlos Nepomuceno wrote:
> ----------------------------------------
>>>
>>> Why don't you use eval()?
>>>
>>
>> Because users can create their own columns, with their own constraints.
>> Therefore the string is user-modifiable, so it cannot be trusted.
>
> I understand your motivation but I don't know what protection ast.literal_eval() is offering that eval() doesn't.
>

Quoting from the manual -

"Safely evaluate an expression node or a string containing a Python 
expression. The string or node provided may only consist of the 
following Python literal structures: strings, bytes, numbers, tuples, 
lists, dicts, sets, booleans, and None."

The operative word is 'safely'. I don't know the details, but it 
prevents the kinds of exploits that can be carried out by malicious code 
using eval().

I believe it is the same problem as SQL injection, which is solved by 
using parameterised queries.

Frank




From fabiosantosart at gmail.com  Mon May 20 04:39:47 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 20 May 2013 09:39:47 +0100
Subject: Question about ast.literal_eval
In-Reply-To: <kncm3b$p2j$1@ger.gmane.org>
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<BLU176-W35D12CEB38B7D64744E8FBD7AF0@phx.gbl>
	<kncm3b$p2j$1@ger.gmane.org>
Message-ID: <CAA=1kxTFe-YbFO4Fz9gQAJKCDDRN45yZwBfurdxHSevR=F8SEQ@mail.gmail.com>

On 20 May 2013 09:19, "Frank Millman" <frank at chagford.com> wrote:
> Quoting from the manual -
>
> "Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, bytes, numbers, tuples, lists, dicts,
sets, booleans, and None."
>
> The operative word is 'safely'. I don't know the details, but it prevents
the kinds of exploits that can be carried out by malicious code using
eval().

Literals are only a subset of expressions. The documentation is a bit
misleading, by stating it accepts a "python expression".

This individual is rightfully confused.
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From steve+comp.lang.python at pearwood.info  Mon May 20 04:15:59 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 20 May 2013 08:15:59 GMT
Subject: Question about ast.literal_eval
References: <knci07$jol$1@ger.gmane.org>
	<BLU176-W37EB377C73CD6D7306247DD7AF0@phx.gbl>
	<knckj0$cft$1@ger.gmane.org>
	<mailman.1873.1369036543.3114.python-list@python.org>
Message-ID: <5199dbbf$0$6574$c3e8da3$5496439d@news.astraweb.com>

On Mon, 20 May 2013 10:55:35 +0300, Carlos Nepomuceno wrote:

> I understand your motivation but I don't know what protection
> ast.literal_eval() is offering that eval() doesn't.

eval will evaluate any legal Python expression:


py> eval("__import__('os').system('echo Mwahaha! Now you are pwned!') or 42")
Mwahaha! And now you are pwned!
42


ast.literal_eval() does exactly what the name says: it will evaluate any 
legal Python LITERAL, including ints, floats, lists, dicts and strings,
but not arbitrary expressions.


py> ast.literal_eval('123')
123
py> ast.literal_eval('[123, None, "spam"]')
[123, None, 'spam']



-- 
Steven


From rosuav at gmail.com  Mon May 20 03:38:18 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 20 May 2013 17:38:18 +1000
Subject: Question about ast.literal_eval
In-Reply-To: <knci07$jol$1@ger.gmane.org>
References: <knci07$jol$1@ger.gmane.org>
Message-ID: <CAPTjJmqfNF1cbC4s0XAje-pi8Dv_ExgpYo4sr0Y-UJ3taQEn4Q@mail.gmail.com>

On Mon, May 20, 2013 at 5:05 PM, Frank Millman <frank at chagford.com> wrote:
> Hi all
>
> I am trying to emulate a SQL check constraint in Python. Quoting from the
> PostgreSQL docs, "A check constraint is the most generic constraint type. It
> allows you to specify that the value in a certain column must satisfy a
> Boolean (truth-value) expression."
>
> The problem is that I want to store the constraint as a string, and I was
> hoping to use ast.literal_eval to evaluate it, but it does not work.
>
>>>> x = 'abc'
>>>> x in ('abc', xyz')
> True
>>>> b = "x in ('abc', 'xyz')"
>>>> eval(b)
> True
>>>> from ast import literal_eval
>>>> literal_eval(b)
> ValueError: malformed node or string: <_ast.Compare object at ...>
>
> Is there a safe way to do what I want? I am using python 3.3.

An SQL constraint has a whole lot that Python can't do conveniently,
and vice versa, so I think you do yourself a disservice by trying to
tie yourself to that.

The problem here is that 'in' is an operator, so this is not a
literal. One possible solution would be to separate out your operator
(and have just a handful permitted), and then use ast.literal_eval for
just the second operand - something like this:

import ast
import operator
ops = {
  'in':lambda x,y: x in y,  # operator.contains has the args backwards
  '==':operator.eq, # or use '=' for more SQL-like syntax
  '<':operator.lt,
  '>':operator.gt,
}

op, value = 'in', "('abc', 'xyz')"
x = 'abc'

if ops[op](x,ast.literal_eval(value)):
  print("Constraint passed")
else:
  print("Ignore this one")

ChrisA


From matt.newville at gmail.com  Mon May 20 22:39:59 2013
From: matt.newville at gmail.com (matt.newville at gmail.com)
Date: Mon, 20 May 2013 19:39:59 -0700 (PDT)
Subject: Question about ast.literal_eval
In-Reply-To: <mailman.1863.1369033561.3114.python-list@python.org>
References: <mailman.1863.1369033561.3114.python-list@python.org>
Message-ID: <bd9faee1-5b93-46d6-b403-091bf071cc77@googlegroups.com>

On Monday, May 20, 2013 2:05:48 AM UTC-5, Frank Millman wrote:
> Hi all
>
>
>
> I am trying to emulate a SQL check constraint in Python. Quoting from
>
> the PostgreSQL docs, "A check constraint is the most generic constraint
>
> type. It allows you to specify that the value in a certain column must
>
> satisfy a Boolean (truth-value) expression."
>
>
>
> The problem is that I want to store the constraint as a string, and I
>
> was hoping to use ast.literal_eval to evaluate it, but it does not work.
>
>
>
>  >>> x = 'abc'
>
>  >>> x in ('abc', xyz')
>
> True
>
>  >>> b = "x in ('abc', 'xyz')"
>
>  >>> eval(b)
>
> True
>
>  >>> from ast import literal_eval
>
>  >>> literal_eval(b)
>
> ValueError: malformed node or string: <_ast.Compare object at ...>
>
>
>
> Is there a safe way to do what I want? I am using python 3.3.
>
>
>
> Thanks
>
>
>
> Frank Millman

You might find the asteval module (https://pypi.python.org/pypi/asteval) useful.   It provides a relatively safe "eval", for example:

    >>> import asteval
    >>> a = asteval.Interpreter()
    >>> a.eval('x = "abc"')
    >>> a.eval('x in ("abc", "xyz")')
    True
    >>> a.eval('import os')
    NotImplementedError
       import os
    'Import' not supported
    >>> a.eval('__import__("os")')
    NameError
       __import__("os")
    name '__import__' is not defined

This works by maintaining an internal namespace (a flat dictionary), and walking the AST generated for the expression.  It supports most Python syntax, 
including if, for, while, and try/except blocks, and function definitions, and with the notable exceptions of eval, exec, class, lambda, yield, and import.   This requires Python2.6 and higher, and does work with Python3.3.

Of course, it is not guaranteed to be completely safe, but it does disallow imports, which seems like the biggest vulnerability concern listed here.  Currently, there is no explicit protection against long-running calculations for denial of service attacks.  If you're exposing an SQL database to user-generated code, that may be worth considering.

Cheers,

--Matt Newville


From frank at chagford.com  Tue May 21 01:54:28 2013
From: frank at chagford.com (Frank Millman)
Date: Tue, 21 May 2013 07:54:28 +0200
Subject: Question about ast.literal_eval
In-Reply-To: <bd9faee1-5b93-46d6-b403-091bf071cc77@googlegroups.com>
References: <mailman.1863.1369033561.3114.python-list@python.org>
	<bd9faee1-5b93-46d6-b403-091bf071cc77@googlegroups.com>
Message-ID: <knf26g$j71$1@ger.gmane.org>

On 21/05/2013 04:39, matt.newville at gmail.com wrote:
>
> You might find the asteval module (https://pypi.python.org/pypi/asteval) useful.   It provides a relatively safe "eval", for example:
>
>      >>> import asteval
>      >>> a = asteval.Interpreter()
>      >>> a.eval('x = "abc"')
>      >>> a.eval('x in ("abc", "xyz")')
>      True
>      >>> a.eval('import os')
>      NotImplementedError
>         import os
>      'Import' not supported
>      >>> a.eval('__import__("os")')
>      NameError
>         __import__("os")
>      name '__import__' is not defined
>
> This works by maintaining an internal namespace (a flat dictionary), and walking the AST generated for the expression.  It supports most Python syntax,
> including if, for, while, and try/except blocks, and function definitions, and with the notable exceptions of eval, exec, class, lambda, yield, and import.   This requires Python2.6 and higher, and does work with Python3.3.
>
> Of course, it is not guaranteed to be completely safe, but it does disallow imports, which seems like the biggest vulnerability concern listed here.  Currently, there is no explicit protection against long-running calculations for denial of service attacks.  If you're exposing an SQL database to user-generated code, that may be worth considering.

Thanks for this, Matt. I will definitely look into it.

Frank





From sabri.pllana at gmail.com  Mon May 20 03:08:55 2013
From: sabri.pllana at gmail.com (SP)
Date: Mon, 20 May 2013 00:08:55 -0700 (PDT)
Subject: CFP: MuCoCoS Workshop at PACT-2013 (Edinburgh, Scotland, UK)
Message-ID: <7ea671fa-f3fe-4c59-ab5f-47f660681195@googlegroups.com>

                      CALL FOR PAPERS:

6th International Workshop on Multi/many-Core Computing Systems
                       (MuCoCoS-2013)

          September 7, 2013, Edinburgh, Scotland, UK

       in conjunction with the 22nd Int. Conference on
  Parallel Architectures and Compilation Techniques (PACT-2013)

        http://www.ida.liu.se/conferences/mucocos2013


AIMS AND SCOPE

The pervasiveness of homogeneous and heterogeneous multi-core and
many-core processors, in a large spectrum of systems from embedded and
general-purpose to high-end computing systems, poses major challenges
to software industry. In general, there is no guarantee that software
developed for a particular architecture will be executable (that is functional)
on another architecture. Furthermore, ensuring that the software preserves
some aspects of performance behavior (such as temporal or energy efficiency)
across different such architectures is an open research issue.

Therefore, this workshop focuses on language level, system software and
architectural solutions for performance portability
across different architectures and for automated performance tuning.

The topics of the MuCoCoS workshop include but are not limited to:

 * Performance measurement, modeling, analysis and tuning
 * Portable programming models, languages and compilation techniques
 * Run-time systems and hardware support mechanisms for auto-tuning
 * Tunable algorithms and data structures
 * Case studies highlighting performance portability and tuning.

As the sixth workshop in the series MuCoCoS 2008 (Barcelona, Spain),
MuCoCoS 2009 (Fukuoka, Japan), MuCoCoS 2010 (Krakow, Poland),
MuCoCoS 2011 (Seoul, Korea), and MuCoCoS 2012 (Salt Lake City, USA),
MuCoCoS 2013 will be held in Edinburgh, UK,
in conjunction with the 22nd International Conference on
Parallel Architectures and Compilation Techniques (PACT 2013).


SUBMISSION GUIDELINES

The papers should be prepared using the IEEE format
(two-column, 10pt, LaTeX users please use style IEEEtran.cls),
and no longer than 10 pages. Submitted papers will be carefully
evaluated based on originality, significance to workshop topics,
technical soundness, and presentation quality.

Please submit your paper (as PDF, viewable by Adobe Reader v5.0
or higher, with all fonts embedded please) electronically using
the online submission system
https://www.easychair.org/conferences/?conf=mucocos2013

Submission of the paper implies that, should the paper be accepted,
at least one of the authors will register and present the paper at
the workshop.

Accepted papers will be published in electronic form in
IEEE Xplore (confirmation pending).
They will also be included in the PACT USB proceedings.
We also plan to invite authors of the best MuCoCoS papers after
the workshop to submit their extended workshop papers to a special
issue of Computing Journal (Springer) (confirmation pending).


IMPORTANT DATES

Submission:   May 27, 2013 (Firm Deadline)
Notification: June 23, 2013
Camera-ready: July 7, 2013
Workshop:     September 7, 2013


WORKSHOP ORGANIZATION

Christoph Kessler, Link?ping University, Sweden, program chair
Sabri Pllana, Linnaeus University, Sweden, co-chair


PROGRAM COMMITTEE

Marco Aldinucci, Univ. of Torino, Italy
Beverly Bachmayer, Intel, Germany
David Bader, Georgia Tech, USA
Jacob Barhen, Oak Ridge National Lab, USA
Siegfried Benkner, Univ. of Vienna, Austria
Franz Franchetti, Carnegie Mellon University, USA
Grigori Fursin, INRIA, France
J?rg Keller, FernUniv. Hagen, Germany
Lasse Natvig, NTNU Trondheim, Norway
Mitsuhisa Sato, Univ. of Tsukuba, Japan
Samuel Thibault, INRIA / Univ. of Bordeaux, France
Philippas Tsigas, Chalmers University, Sweden
Jakub Yaghob, Charles University Prague, Czech Republic




From andrea.crotti.0 at gmail.com  Mon May 20 14:00:30 2013
From: andrea.crotti.0 at gmail.com (andrea crotti)
Date: Mon, 20 May 2013 20:00:30 +0200
Subject: pip and different branches?
Message-ID: <CAF_E5JYQT6Aui=zbBdSZ=E+56q63AOF=HPk0H-NOajqm+E3RsQ@mail.gmail.com>

We use github and we work on many different branches at the same time.

The problem is that we have >5 repos now, and for each repo we might
have the same branches on all of them.

Now we use pip and install requirements such as:
git+ssh://git at github.com/repo.git at dev

Now the problem is that the requirements file are also under revision
control, and constantly we end up in the situation that when we merge
branches the branch settings get messed up, because we forget to change
them.

I was looking for a solution for this that would allow me to:
- use the branch of the "main" repo for all the dependencies
- fallback on master if that branch doesn't exist

I thought about a few options:
1. create a wrapper for PIP that manipulates the requirement file, that now
   would become templates.
   In this way I would have to know however if a branch exist or not,
   and I didn't find a way to do that without cloning the repo.

2. modify PIP to not fail when checking out a non existing branch, so
   that if it's not found it falls back on master automatically.

3. use some git magic hooks but I'm not sure what exactly

4. stop using virtualenv + pip and use something smarter that handles
   this.

Any suggestions?
Thanks
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From carlosnepomuceno at outlook.com  Tue May 21 01:17:36 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 21 May 2013 08:17:36 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
Message-ID: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>

Is there a way to format integers with thousands separator (digit grouping) like the format specifier of str.format()?

I'm currently using the following:

>>> sys.stdout.write('Number = %s\n' % '{:,.0f}'.format(x))
Number = 12,345

'x' is unsigned integer so it's like using a sledgehammer to crack a nut!

I'd like to have something like:

sys.stdout.write('Number = %,u\n' % x)


Is that possible? How can I do it if not already available? 		 	   		  

From nad at acm.org  Tue May 21 01:44:08 2013
From: nad at acm.org (Ned Deily)
Date: Mon, 20 May 2013 22:44:08 -0700
Subject: PEP 378: Format Specifier for Thousands Separator
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
Message-ID: <nad-F52CE7.22440720052013@news.gmane.org>

In article <BLU176-W10190CB892A0414C988A05D7A80 at phx.gbl>,
 Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> Is there a way to format integers with thousands separator (digit grouping) 
> like the format specifier of str.format()?> 
> I'm currently using the following:> 
> >>> sys.stdout.write('Number = %s\n' % '{:,.0f}'.format(x))
> Number = 12,345> 
> 'x' is unsigned integer so it's like using a sledgehammer to crack a nut!> 
> I'd like to have something like:
> sys.stdout.write('Number = %,u\n' % x)
> Is that possible? How can I do it if not already available?                   

For Python 3.2+ or 2.7, why not just:

>>> print('Number = {:,}'.format(x))
Number = 12,345

-- 
 Ned Deily,
 nad at acm.org



From alyssonbruno at gmail.com  Tue May 21 08:03:13 2013
From: alyssonbruno at gmail.com (Alysson Bruno)
Date: Tue, 21 May 2013 09:03:13 -0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <nad-F52CE7.22440720052013@news.gmane.org>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
Message-ID: <CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>

This work in 3.1+:

$ python3
Python 3.1.3 (r313:86834, Nov 28 2010, 11:28:10)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> one_number = 1234567
>>> print('number={:,}'.format(one_number))
number=1,234,567
>>>

paz e amor (love and peace),

Alysson Bruno
===============================================
Palmas(TO)
Brasil

Blog: http://abruno.com
Twitter: http://twitter.com/alyssonbruno
Facebook: http://www.facebook.com/ProfessorAlyssonBruno

=================================================================
*Meu alterego Escritor:*

Leia alguns contos que escrevo, n?o esque?a de me dar sua opini?o:
http://goo.gl/Wjn4p <http://goo.gl/AXv1g>

=================================================================


On Tue, May 21, 2013 at 2:44 AM, Ned Deily <nad at acm.org> wrote:

> In article <BLU176-W10190CB892A0414C988A05D7A80 at phx.gbl>,
>  Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> > Is there a way to format integers with thousands separator (digit
> grouping)
> > like the format specifier of str.format()?>
> > I'm currently using the following:>
> > >>> sys.stdout.write('Number = %s\n' % '{:,.0f}'.format(x))
> > Number = 12,345>
> > 'x' is unsigned integer so it's like using a sledgehammer to crack a
> nut!>
> > I'd like to have something like:
> > sys.stdout.write('Number = %,u\n' % x)
> > Is that possible? How can I do it if not already available?
>
> For Python 3.2+ or 2.7, why not just:
>
> >>> print('Number = {:,}'.format(x))
> Number = 12,345
>
> --
>  Ned Deily,
>  nad at acm.org
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From carlosnepomuceno at outlook.com  Tue May 21 14:49:28 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 21 May 2013 21:49:28 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
Message-ID: <BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>

________________________________
> From: alyssonbruno at gmail.com 
> Date: Tue, 21 May 2013 09:03:13 -0300 
> Subject: Re: PEP 378: Format Specifier for Thousands Separator 
> To: python-list at python.org 
>  
> This work in 3.1+: 
>  
> $ python3 
> Python 3.1.3 (r313:86834, Nov 28 2010, 11:28:10) 
> [GCC 4.4.5] on linux2 
> Type "help", "copyright", "credits" or "license" for more information. 
> >>> one_number = 1234567 
> >>> print('number={:,}'.format(one_number)) 
> number=1,234,567 
> >>> 
>  

Thank you, but let me rephrase it. I'm already using str.format() but I'd like to use '%' (BINARY_MODULO) operator instead.

I've looked into the source code of CPython 2.7.5 and I've found no evidence of the thousands separator been implemented on formatint() in "Objects/unicodeobject.c".

I also didn't find the _PyString_FormatLong() used in formatlong(). Where is _PyString_FormatLong() located?

So, the question is: Where would I change the CPython 2.7.5 source code to enable '%' (BINARY_MODULO) to format using the thousands separator like str.format() does, such as:

>>>sys.stderr.write('%,d\n' % 1234567)
1,234,567 		 	   		  

From kwpolska at gmail.com  Tue May 21 15:06:11 2013
From: kwpolska at gmail.com (=?UTF-8?B?Q2hyaXMg4oCcS3dwb2xza2HigJ0gV2Fycmljaw==?=)
Date: Tue, 21 May 2013 21:06:11 +0200
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
Message-ID: <CAMw+j7JdSe2CAs=FF0iYiN-KkmR7uy5g+D3muvFcpvR+HRquOw@mail.gmail.com>

On Tue, May 21, 2013 at 8:49 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> Thank you, but let me rephrase it. I'm already using str.format() but I'd like to use '%' (BINARY_MODULO) operator instead.

There is no real reason to do this.  `str.format()` is the new shiny
thing you should be using all the time.  Also, '%' is BINARY_MODULO
(where did you even get that name from?) if and only if you have two
numbers, and it performs the modulo division (eg. 27 % 5 = 2)

> So, the question is: Where would I change the CPython 2.7.5 source code to enable '%' (BINARY_MODULO) to format using the thousands separator like str.format() does, such as:
>
>>>>sys.stderr.write('%,d\n' % 1234567)
> 1,234,567

This will make your code unportable and useless, depending on one
patch you made.  Please don?t do that.  Instead,

> >>> sys.stdout.write('Number = %s\n' % '{:,.0f}'.format(x))
> Number = 12,345
>
> 'x' is unsigned integer so it's like using a sledgehammer to crack a nut!

In Python?  Tough luck, every int is signed.  And it isn?t just a
sledgehammer, it?s something worse.  Just do that:

>>> sys.stdout.write('Number = {:,.0f}\n'.format(x))

Much more peaceful.

You can also do a print, like everyone sane would.  Where did you
learn Python from?  ?Python Worst Practice for Dummies??

--
Kwpolska <http://kwpolska.tk> | GPG KEY: 5EAAEA16
stop html mail                | always bottom-post
http://asciiribbon.org        | http://caliburn.nl/topposting.html


From carlosnepomuceno at outlook.com  Tue May 21 15:39:35 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 21 May 2013 22:39:35 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <CAMw+j7JdSe2CAs=FF0iYiN-KkmR7uy5g+D3muvFcpvR+HRquOw@mail.gmail.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CAMw+j7JdSe2CAs=FF0iYiN-KkmR7uy5g+D3muvFcpvR+HRquOw@mail.gmail.com>
Message-ID: <BLU176-W13FDD9818B484C2ADDD109D7A80@phx.gbl>

----------------------------------------
> From: kwpolska at gmail.com
> Date: Tue, 21 May 2013 21:06:11 +0200
> Subject: Re: PEP 378: Format Specifier for Thousands Separator
> To: carlosnepomuceno at outlook.com
> CC: python-list at python.org
>
> On Tue, May 21, 2013 at 8:49 PM, Carlos Nepomuceno
> <carlosnepomuceno at outlook.com> wrote:
>> Thank you, but let me rephrase it. I'm already using str.format() but I'd like to use '%' (BINARY_MODULO) operator instead.
>
> There is no real reason to do this. `str.format()` is the new shiny
> thing you should be using all the time. Also, '%' is BINARY_MODULO
> (where did you even get that name from?) if and only if you have two
> numbers, and it performs the modulo division (eg. 27 % 5 = 2)

I did:

>>> def fmt(s):
...???? return '%s' % s
...
>>> import dis
>>> dis.dis(fmt)
? 2?????????? 0 LOAD_CONST?????????????? 1 ('%s')
????????????? 3 LOAD_FAST??????????????? 0 (s)
????????????? 6 BINARY_MODULO
????????????? 7 RETURN_VALUE
>>>

Then I've looked for 'BINARY_MODULO' in "Python/ceval.c" and found:

??????? case BINARY_MODULO:
??????????? w = POP();
??????????? v = TOP();
??????????? if (PyString_CheckExact(v))
??????????????? x = PyString_Format(v, w);
??????????? else
??????????????? x = PyNumber_Remainder(v, w);


Then I've looked for 'PyString_Format' and found it in "Objects/stringobject.c"

Analysing the code of "stringobject.c" I've found formatint() and formatlong().

I'm not using str.format() because it's slower than '%' and because I love '%'. str.format() looks like Java shit to me!

>> So, the question is: Where would I change the CPython 2.7.5 source code to enable '%' (BINARY_MODULO) to format using the thousands separator like str.format() does, such as:
>>
>>>>>sys.stderr.write('%,d\n' % 1234567)
>> 1,234,567
>
> This will make your code unportable and useless, depending on one
> patch you made. Please don?t do that. Instead,

I'm just learning how to improve things! ;)

>>>>> sys.stdout.write('Number = %s\n' % '{:,.0f}'.format(x))
>> Number = 12,345
>>
>> 'x' is unsigned integer so it's like using a sledgehammer to crack a nut!
>
> In Python? Tough luck, every int is signed. And it isn?t just a
> sledgehammer, it?s something worse. Just do that:
>
>>>> sys.stdout.write('Number = {:,.0f}\n'.format(x))
>
> Much more peaceful.

Indeed! I just cut and pasted my code to create an example for the message. The actual format operation isn't done at the sys.stdout.write().

> You can also do a print, like everyone sane would. Where did you
> learn Python from? ?Python Worst Practice for Dummies??

lol I'm learning from my big mistakes up to now and a ton of online tutorials, besides "Dive into Python" (2004)[1], "Python Programming" (2012)[2] and "Programming Python, 3rd Ed" (2006) [print]

print isn't thread safe. That's why I've chosen sys.stdout.write() -- it's faster and thread safe by default.

I don't need any fancy formating, just need to send the string to screen.


[1] http://www.diveintopython.net/
[1] http://en.wikibooks.org/wiki/Python_Programming

> --
> Kwpolska <http://kwpolska.tk> | GPG KEY: 5EAAEA16
> stop html mail | always bottom-post
> http://asciiribbon.org | http://caliburn.nl/topposting.html 		 	   		  

From carlosnepomuceno at outlook.com  Tue May 21 15:41:51 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 21 May 2013 22:41:51 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <BLU176-W13FDD9818B484C2ADDD109D7A80@phx.gbl>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CAMw+j7JdSe2CAs=FF0iYiN-KkmR7uy5g+D3muvFcpvR+HRquOw@mail.gmail.com>,
	<BLU176-W13FDD9818B484C2ADDD109D7A80@phx.gbl>
Message-ID: <BLU176-W149EA38BC8CADA323FC0BFD7A80@phx.gbl>

> Analysing the code of "stringobject.c" I've found formatint() and formatlong().

I mean _PyString_FormatLong() 		 	   		  

From ethan at stoneleaf.us  Tue May 21 15:41:36 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 21 May 2013 12:41:36 -0700
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <CAMw+j7JdSe2CAs=FF0iYiN-KkmR7uy5g+D3muvFcpvR+HRquOw@mail.gmail.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CAMw+j7JdSe2CAs=FF0iYiN-KkmR7uy5g+D3muvFcpvR+HRquOw@mail.gmail.com>
Message-ID: <519BCDF0.9050802@stoneleaf.us>

On 05/21/2013 12:06 PM, Chris ?Kwpolska? Warrick wrote:
> On Tue, May 21, 2013 at 8:49 PM, Carlos Nepomuceno wrote:
>>
>> Thank you, but let me rephrase it. I'm already using str.format() but I'd like to use '%' (BINARY_MODULO) operator instead.
>
> There is no real reason to do this.  `str.format()` is the new shiny
> thing you should be using all the time.

.format() is useful, and has it's place, but % formatting is not going away.


>> So, the question is: Where would I change the CPython 2.7.5 source code to enable '%' (BINARY_MODULO) to format using the thousands separator like str.format() does, such as:
>>
>>--> sys.stderr.write('%,d\n' % 1234567)
>> 1,234,567
>
> This will make your code unportable and useless, depending on one
> patch you made.  Please don?t do that.

Agreed.  Unless you're willing to have your programs either run differently, or not at all, on other systems this is the 
wrong way to fix it.


> Where did you learn Python from?  ?Python Worst Practice for Dummies??

Chris Warrick,

Was that necessary? Useful?  Helpful in any way?  If you can't be civil, keep your posts to yourself.

--
~Ethan~


From skip at pobox.com  Tue May 21 15:13:05 2013
From: skip at pobox.com (Skip Montanaro)
Date: Tue, 21 May 2013 14:13:05 -0500
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
Message-ID: <CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>

> Thank you, but let me rephrase it. I'm already using str.format() but I'd like to use '%' (BINARY_MODULO) operator instead.

That's unlikely to change.  If not deprecated already string
interpolation using the modulo operator has lost favor to the string
object's format method.

You might be able to get by with a change of your LOCALE setting
and/or a peek at the documentation for the locale module.

Skip


From breamoreboy at yahoo.co.uk  Tue May 21 15:26:41 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 21 May 2013 20:26:41 +0100
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
Message-ID: <knghok$3bd$1@ger.gmane.org>

On 21/05/2013 20:13, Skip Montanaro wrote:
>> Thank you, but let me rephrase it. I'm already using str.format() but I'd like to use '%' (BINARY_MODULO) operator instead.
>
> That's unlikely to change.  If not deprecated already string
> interpolation using the modulo operator has lost favor to the string
> object's format method.
>

Please stop perpetuating this myth, see 
http://mail.python.org/pipermail/python-dev/2012-February/116789.html 
and http://bugs.python.org/issue14123

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From bahamutzero8825 at gmail.com  Tue May 21 15:53:54 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 21 May 2013 14:53:54 -0500
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <knghok$3bd$1@ger.gmane.org>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org>
Message-ID: <519BD0D2.5080203@gmail.com>

On 2013.05.21 14:26, Mark Lawrence wrote:
> On 21/05/2013 20:13, Skip Montanaro wrote:
>>> Thank you, but let me rephrase it. I'm already using str.format() but I'd like to use '%' (BINARY_MODULO) operator instead.
>>
>> That's unlikely to change.  If not deprecated already string
>> interpolation using the modulo operator has lost favor to the string
>> object's format method.
>>
> 
> Please stop perpetuating this myth, see 
> http://mail.python.org/pipermail/python-dev/2012-February/116789.html 
> and http://bugs.python.org/issue14123
> 
What myth? People should indeed be using .format(), but no one said % formatting was going away soon. Also, the suggested change to the docs
wasn't made and the issue is closed. The current docs do not say that % formatting isn't going to be deprecated, but it does mention its
caveats and suggests .format(). If you are trying to say that % formatting will never ever go away, then you are wrong. It is highly
unlikely to go away in a 3.x release, but /may/ get phased out in Python 4.0.
-- 
CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1


From carlosnepomuceno at outlook.com  Tue May 21 16:22:24 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 21 May 2013 23:22:24 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <519BD0D2.5080203@gmail.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org>, <519BD0D2.5080203@gmail.com>
Message-ID: <BLU176-W31AF69CC0DA3728360182DD7A80@phx.gbl>

----------------------------------------
> Date: Tue, 21 May 2013 14:53:54 -0500
> From: bahamutzero8825 at gmail.com
> To: python-list at python.org
[...]
>>
> What myth? People should indeed be using .format(), but no one said % formatting was going away soon. Also, the suggested change to the docs
> wasn't made and the issue is closed. The current docs do not say that % formatting isn't going to be deprecated, but it does mention its
> caveats and suggests .format(). If you are trying to say that % formatting will never ever go away, then you are wrong. It is highly
> unlikely to go away in a 3.x release, but /may/ get phased out in Python 4.0.

I vote for keeping str.__mod__()!

Anyway, is it possible to overload str.__mod__() without deriving a class? I mean to have something like:

old_mod = str.__mod__
def new_mod(x):
??? global old_mod
??? try:
? ?? ?? old_mod(x)
??? except ValueError, ex:
??????? #catch ValueError: unsupported format character ',' (0x2c) at index 1
? ? ? ? #process new '%,d' format here
??????? return '{:,}'.format(x)? #just to illustrate the behaviour. it would have it's own faster code

str.__mod__ = new_mod? #this raises TypeError: can't set attributes of built-in/extension type 'str'
sys.stdout.write('num=%,d\n' % 1234567)


> --
> CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From steve+comp.lang.python at pearwood.info  Tue May 21 22:42:56 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 22 May 2013 02:42:56 GMT
Subject: PEP 378: Format Specifier for Thousands Separator
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org> <519BD0D2.5080203@gmail.com>
	<mailman.1939.1369167746.3114.python-list@python.org>
Message-ID: <519c30b0$0$6599$c3e8da3$5496439d@news.astraweb.com>

On Tue, 21 May 2013 23:22:24 +0300, Carlos Nepomuceno wrote:

> Anyway, is it possible to overload str.__mod__() without deriving a
> class? I mean to have something like:

No, not in Python. If you want to monkey-patch built-in classes on the 
fly, with all the troubles that causes, use Ruby.


-- 
Steven


From carlosnepomuceno at outlook.com  Tue May 21 22:56:53 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 22 May 2013 05:56:53 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <519c30b0$0$6599$c3e8da3$5496439d@news.astraweb.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org> <519BD0D2.5080203@gmail.com>,
	<mailman.1939.1369167746.3114.python-list@python.org>,
	<519c30b0$0$6599$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <BLU176-W5214170EA2C28704CD36FD7A90@phx.gbl>

----------------------------------------
> From: steve+comp.lang.python at pearwood.info
> Subject: Re: PEP 378: Format Specifier for Thousands Separator
> Date: Wed, 22 May 2013 02:42:56 +0000
> To: python-list at python.org
>
> On Tue, 21 May 2013 23:22:24 +0300, Carlos Nepomuceno wrote:
>
>> Anyway, is it possible to overload str.__mod__() without deriving a
>> class? I mean to have something like:
>
> No, not in Python. If you want to monkey-patch built-in classes on the
> fly, with all the troubles that causes, use Ruby.
>

So, the only alternative to have "'%,d' % x" rendering the thousands separator output would a C source code modification?

> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From steve+comp.lang.python at pearwood.info  Tue May 21 23:08:54 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 22 May 2013 03:08:54 GMT
Subject: PEP 378: Format Specifier for Thousands Separator
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org> <519BD0D2.5080203@gmail.com>
	<mailman.1939.1369167746.3114.python-list@python.org>
	<519c30b0$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1946.1369191420.3114.python-list@python.org>
Message-ID: <519c36c6$0$6599$c3e8da3$5496439d@news.astraweb.com>

On Wed, 22 May 2013 05:56:53 +0300, Carlos Nepomuceno wrote:

> ----------------------------------------
>> From: steve+comp.lang.python at pearwood.info Subject: Re: PEP 378: Format
>> Specifier for Thousands Separator Date: Wed, 22 May 2013 02:42:56 +0000
>> To: python-list at python.org
>>
>> On Tue, 21 May 2013 23:22:24 +0300, Carlos Nepomuceno wrote:
>>
>>> Anyway, is it possible to overload str.__mod__() without deriving a
>>> class? I mean to have something like:
>>
>> No, not in Python. If you want to monkey-patch built-in classes on the
>> fly, with all the troubles that causes, use Ruby.
>>
>>
> So, the only alternative to have "'%,d' % x" rendering the thousands
> separator output would a C source code modification?

That's one alternative. But the language you would be then running will 
no longer be Python.

Another alternative would be to write a pre-processor that parses your 
Python source code, extracts any reference to the above, and replaces it 
with a call to the appropriate format call. But not only is that a lot of 
work for very little gain, but it's also more or less impossible to do in 
full generality. And again, what you are running will be something 
different than Python, it will be Python plus a pre-processor.


Don't fight the language. You will lose.



-- 
Steven


From carlosnepomuceno at outlook.com  Tue May 21 23:38:45 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 22 May 2013 06:38:45 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <519c36c6$0$6599$c3e8da3$5496439d@news.astraweb.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org> <519BD0D2.5080203@gmail.com>,
	<mailman.1939.1369167746.3114.python-list@python.org>,
	<519c30b0$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.1946.1369191420.3114.python-list@python.org>,
	<519c36c6$0$6599$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <BLU176-W34B34E0A92C69D61DFCE36D7A90@phx.gbl>

----------------------------------------
> From: steve+comp.lang.python at pearwood.info
> Subject: Re: PEP 378: Format Specifier for Thousands Separator
> Date: Wed, 22 May 2013 03:08:54 +0000
> To: python-list at python.org
[...]
>> So, the only alternative to have "'%,d' % x" rendering the thousands
>> separator output would a C source code modification?
>
> That's one alternative. But the language you would be then running will
> no longer be Python.
>
> Another alternative would be to write a pre-processor that parses your
> Python source code, extracts any reference to the above, and replaces it
> with a call to the appropriate format call. But not only is that a lot of
> work for very little gain, but it's also more or less impossible to do in
> full generality. And again, what you are running will be something
> different than Python, it will be Python plus a pre-processor.
>
>
> Don't fight the language. You will lose.

Not fighting the language. In fact it's not even a language issue.
All I need is a standard library[1] improvement: "%,d"! That's all!

Just to put in perspective the performance difference of str.__mod__() and str.format():

C:\Python27>python -m timeit -cv -n10000000 "'%d'%12345"
raw times: 0.386 0.38 0.373
10000000 loops, best of 3: 0.0373 usec per loop

C:\Python27>python -m timeit -cv -n10000000 "'{:d}'.format(12345)"
raw times: 7.91 7.89 7.98
10000000 loops, best of 3: 0.789 usec per loop

C:\Python27>python -m timeit -cv -n10000000 "'{:,d}'.format(12345)"
raw times: 8.7 8.67 8.78
10000000 loops, best of 3: 0.867 usec per loop

That shows str.format() is 20 times slower than str.__mod__() for a simple decimal integer literal formatting.
And it's additionally 10% slower if the thousands separator format specifier (',') is used.

[1] I think that translates to Python source code in 'Objects/stringobject.c' and maybe 'Objects/unicodeobject.c'

>
>
> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From ned at nedbatchelder.com  Wed May 22 07:25:13 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Wed, 22 May 2013 07:25:13 -0400
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <BLU176-W34B34E0A92C69D61DFCE36D7A90@phx.gbl>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org> <519BD0D2.5080203@gmail.com>,
	<mailman.1939.1369167746.3114.python-list@python.org>,
	<519c30b0$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.1946.1369191420.3114.python-list@python.org>,
	<519c36c6$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<BLU176-W34B34E0A92C69D61DFCE36D7A90@phx.gbl>
Message-ID: <519CAB19.7080203@nedbatchelder.com>


On 5/21/2013 11:38 PM, Carlos Nepomuceno wrote:
>> From:steve+comp.lang.python at pearwood.info
>> >Subject: Re: PEP 378: Format Specifier for Thousands Separator
>> >Date: Wed, 22 May 2013 03:08:54 +0000
>> >To:python-list at python.org
> [...]
>>> >>So, the only alternative to have "'%,d' % x" rendering the thousands
>>> >>separator output would a C source code modification?
>> >
>> >That's one alternative. But the language you would be then running will
>> >no longer be Python.
>> >
>> >Another alternative would be to write a pre-processor that parses your
>> >Python source code, extracts any reference to the above, and replaces it
>> >with a call to the appropriate format call. But not only is that a lot of
>> >work for very little gain, but it's also more or less impossible to do in
>> >full generality. And again, what you are running will be something
>> >different than Python, it will be Python plus a pre-processor.
>> >
>> >
>> >Don't fight the language. You will lose.
> Not fighting the language. In fact it's not even a language issue.
> All I need is a standard library[1] improvement: "%,d"! That's all!

You have to keep in mind that 2.7 is not getting any new features, no 
matter how small they seem.  If you create a patch that implements the 
comma flag in %-formatting, it *might* go into 3.x, but it will not go 
into 2.7.

--Ned.


From carlosnepomuceno at outlook.com  Wed May 22 07:52:15 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 22 May 2013 14:52:15 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <519CAB19.7080203@nedbatchelder.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org> <519BD0D2.5080203@gmail.com>,
	<mailman.1939.1369167746.3114.python-list@python.org>,
	<519c30b0$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.1946.1369191420.3114.python-list@python.org>,
	<519c36c6$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<BLU176-W34B34E0A92C69D61DFCE36D7A90@phx.gbl>,
	<519CAB19.7080203@nedbatchelder.com>
Message-ID: <BLU176-W19D0C3AA0C987AB54C3634D7A90@phx.gbl>

----------------------------------------
> Date: Wed, 22 May 2013 07:25:13 -0400
> From: ned at nedbatchelder.com
[...]
> You have to keep in mind that 2.7 is not getting any new features, no
> matter how small they seem. If you create a patch that implements the
> comma flag in %-formatting, it *might* go into 3.x, but it will not go
> into 2.7.
>
> --Ned.

No problem. I have just discovered i was measuring the wrong thing.

My test case is been optimized at compile time by CPython that treats "'%d' % 12345" as a constant.
My use case is different because I almost have no literals been used with % operator.

So my gain isn't that great. In fact it's faster with str.format() than %, and it's even faster if I use the default format specifier.

C:\Python27>python -m timeit -cv -n10000000 -s"v=12345" "'%d'%v"
raw times: 10.5 10.7 10.7
10000000 loops, best of 3: 1.05 usec per loop

C:\Python27>python -m timeit -cv -n10000000 -s"v=12345" "'{:d}'.format(v)"
raw times: 8.11 8.09 8.02
10000000 loops, best of 3: 0.802 usec per loop

C:\Users\Josue\Documents\Python>python -m timeit -cv -n10000000 -s"v=12345" "'{}'.format(v)"
raw times: 5.3 5.5 5.62
10000000 loops, best of 3: 0.53 usec per loop

Using variables (100% of cases) makes str.format() 50% faster than %. 		 	   		  

From dihedral88888 at gmail.com  Wed May 22 03:14:13 2013
From: dihedral88888 at gmail.com (88888 Dihedral)
Date: Wed, 22 May 2013 00:14:13 -0700 (PDT)
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <mailman.1951.1369193993.3114.python-list@python.org>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,>
	<nad-F52CE7.22440720052013@news.gmane.org>,
	> <CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	> <BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	> <CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	> <knghok$3bd$1@ger.gmane.org> <519BD0D2.5080203@gmail.com>,>
	<mailman.1939.1369167746.3114.python-list@python.org>,
	> <519c30b0$0$6599$c3e8da3$5496439d@news.astraweb.com>, >
	<mailman.1946.1369191420.3114.python-list@python.org>,
	> <519c36c6$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1951.1369193993.3114.python-list@python.org>
Message-ID: <087e4cab-92bd-4a14-aab4-a986e426302b@googlegroups.com>

Carlos Nepomuceno? 2013?5?22????UTC+8??11?38?45????
> ----------------------------------------
> > From: steve+comp.lang.python at pearwood.info
> > Subject: Re: PEP 378: Format Specifier for Thousands Separator
> > Date: Wed, 22 May 2013 03:08:54 +0000
> > To: python-list at python.org
> [...]
> >> So, the only alternative to have "'%,d' % x" rendering the thousands
> >> separator output would a C source code modification?
> >
> > That's one alternative. But the language you would be then running will
> > no longer be Python.
> >
> > Another alternative would be to write a pre-processor that parses your
> > Python source code, extracts any reference to the above, and replaces it
> > with a call to the appropriate format call. But not only is that a lot of
> > work for very little gain, but it's also more or less impossible to do in
> > full generality. And again, what you are running will be something
> > different than Python, it will be Python plus a pre-processor.
> >
> >
> > Don't fight the language. You will lose.
> 
> Not fighting the language. In fact it's not even a language issue.
> All I need is a standard library[1] improvement: "%,d"! That's all!
> 
> Just to put in perspective the performance difference of str.__mod__() and str.format():
> 
> C:\Python27>python -m timeit -cv -n10000000 "'%d'%12345"
> raw times: 0.386 0.38 0.373
> 10000000 loops, best of 3: 0.0373 usec per loop
> 
> C:\Python27>python -m timeit -cv -n10000000 "'{:d}'.format(12345)"
> raw times: 7.91 7.89 7.98
> 10000000 loops, best of 3: 0.789 usec per loop
> 
> C:\Python27>python -m timeit -cv -n10000000 "'{:,d}'.format(12345)"
> raw times: 8.7 8.67 8.78
> 10000000 loops, best of 3: 0.867 usec per loop
> 
> That shows str.format() is 20 times slower than str.__mod__() for a simple decimal integer literal formatting.
> And it's additionally 10% slower if the thousands separator format specifier (',') is used.
> 
> [1] I think that translates to Python source code in 'Objects/stringobject.c' and maybe 'Objects/unicodeobject.c'
> 
> >
> >
> > --
> > Steven
> > --
> > http://mail.python.org/mailman/listinfo/python-list

The conversions of the  32 bit integers and 64 bit floats
 to the strings of the  base 10 digits require an 
efficint div and mod normally in the low level.


From carlosnepomuceno at outlook.com  Tue May 21 16:02:10 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 21 May 2013 23:02:10 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <knghok$3bd$1@ger.gmane.org>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org>
Message-ID: <BLU176-W402ABE3A65F1ABDD5CD1D5D7A80@phx.gbl>

----------------------------------------
> To: python-list at python.org
> From: breamoreboy at yahoo.co.uk
> Subject: Re: PEP 378: Format Specifier for Thousands Separator
> Date: Tue, 21 May 2013 20:26:41 +0100
>
> On 21/05/2013 20:13, Skip Montanaro wrote:
>>> Thank you, but let me rephrase it. I'm already using str.format() but I'd like to use '%' (BINARY_MODULO) operator instead.
>>
>> That's unlikely to change. If not deprecated already string
>> interpolation using the modulo operator has lost favor to the string
>> object's format method.
>>

I used to think str.__mod__() was going to be deprecated until Steven told me it was a myth! Think I got that idea from the own Python docs, but it's gone by now. Nevermind...

The fact is I have no need for str.format(). It's slow and awkward. str.format() looks like COBOL/Java idiom to me. I love Python! '%' is much more cool!!!

> Please stop perpetuating this myth, see
> http://mail.python.org/pipermail/python-dev/2012-February/116789.html
> and http://bugs.python.org/issue14123
>
> --
> If you're using GoogleCrap? please read this
> http://wiki.python.org/moin/GoogleGroupsPython.
>
> Mark Lawrence
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From steve+comp.lang.python at pearwood.info  Tue May 21 22:59:22 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 22 May 2013 02:59:22 GMT
Subject: PEP 378: Format Specifier for Thousands Separator
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org>
	<mailman.1936.1369166040.3114.python-list@python.org>
Message-ID: <519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>

On Tue, 21 May 2013 14:53:54 -0500, Andrew Berg wrote:

> On 2013.05.21 14:26, Mark Lawrence wrote:

>> Please stop perpetuating this myth, see
>> http://mail.python.org/pipermail/python-dev/2012-February/116789.html
>> and http://bugs.python.org/issue14123
>> 
> What myth? 

The myth that % string formatting is deprecated. It is not deprecated.

> People should indeed be using .format(), 

If it is useful to them, and not too slow, or indeed if they merely want 
to. And if not, then not.

This is a good case where the original poster *should* use str.format, 
since it does exactly what he wants, and % does not. Python gives you 
many tools, and the wise man uses the right tool for the job. Sometimes 
that is % and sometimes it is str.format and sometimes it is 
string.Template.

That str.format looks like Java is irrelevant. Method call syntax is 
common in Python, and is not original to Java. Besides, Python looks like 
many languages: some parts look like Java, some parts look like C, some 
parts remind me of functional languages like Lisp and Haskell, and some 
parts look like Algol or Pascal.


> but no one said % formatting was going away soon.

True, but only for the definition "no one = all the people who insist 
that % is deprecated, or soon to be deprecated".


> Also, the suggested change to the docs
> wasn't made and the issue is closed. The current docs do not say that %
> formatting isn't going to be deprecated, but it does mention its caveats
> and suggests .format(). If you are trying to say that % formatting will
> never ever go away, then you are wrong. It is highly unlikely to go away
> in a 3.x release, but /may/ get phased out in Python 4.0.

What happens in Python 4000 is irrelevant. If somebody is trying to 
"future proof" their code for a version that *may never exist*, and if it 
does exist is likely to be six or eight years away from even starting the 
design phase, they are wasting their time. It is hard enough to track a 
moving target, it is impossible to track a target that isn't even a gleam 
in GvR's eye yet.



-- 
Steven


From bahamutzero8825 at gmail.com  Tue May 21 23:38:01 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 21 May 2013 22:38:01 -0500
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org>
	<mailman.1936.1369166040.3114.python-list@python.org>
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <519C3D99.5040107@gmail.com>

On 2013.05.21 21:59, Steven D'Aprano wrote:
> On Tue, 21 May 2013 14:53:54 -0500, Andrew Berg wrote:
> 
>> On 2013.05.21 14:26, Mark Lawrence wrote:
> 
>>> Please stop perpetuating this myth, see
>>> http://mail.python.org/pipermail/python-dev/2012-February/116789.html
>>> and http://bugs.python.org/issue14123
>>> 
>> What myth? 
> 
> The myth that % string formatting is deprecated. It is not deprecated.
Skip didn't say that it was deprecated.

>> but no one said % formatting was going away soon.
> 
> True, but only for the definition "no one = all the people who insist 
> that % is deprecated, or soon to be deprecated".
Perhaps I missed something, but who is insisting this?

> What happens in Python 4000 is irrelevant. If somebody is trying to 
> "future proof" their code for a version that *may never exist*, and if it 
> does exist is likely to be six or eight years away from even starting the 
> design phase, they are wasting their time. It is hard enough to track a 
> moving target, it is impossible to track a target that isn't even a gleam 
> in GvR's eye yet.
I think you misunderstand. I'm not suggesting that format() be used simply because % formatting could be deprecated at some unknown time
years from now; I was clarifying the status of % formatting.
-- 
CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1


From skip at pobox.com  Wed May 22 06:45:12 2013
From: skip at pobox.com (Skip Montanaro)
Date: Wed, 22 May 2013 05:45:12 -0500
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <519C3D99.5040107@gmail.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org>
	<mailman.1936.1369166040.3114.python-list@python.org>
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<519C3D99.5040107@gmail.com>
Message-ID: <CANc-5Uxib1NvVZOKzGiB-QyLRkZ7qUTx_FN6Wx8JT2x+8psuFA@mail.gmail.com>

>>>> Please stop perpetuating this myth, see
>>>> http://mail.python.org/pipermail/python-dev/2012-February/116789.html
>>>> and http://bugs.python.org/issue14123
>>>>
>>> What myth?
>>
>> The myth that % string formatting is deprecated. It is not deprecated.
> Skip didn't say that it was deprecated.

I didn't mean to create a tempest in a teapot.  I was away from
comp.lang.python, python-bugs, and python-dev for a few years.  In
particular, I didn't ever see the aforementioned thread from Feb 2012.
 Had I known of that thread I would have worded the sentence which
shall not be repeated differently.

My apologies...

Skip


From steve+comp.lang.python at pearwood.info  Wed May 22 10:58:08 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 22 May 2013 14:58:08 GMT
Subject: PEP 378: Format Specifier for Thousands Separator
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org>
	<mailman.1936.1369166040.3114.python-list@python.org>
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<519C3D99.5040107@gmail.com>
	<mailman.1958.1369219519.3114.python-list@python.org>
Message-ID: <519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>

On Wed, 22 May 2013 05:45:12 -0500, Skip Montanaro wrote:

> I didn't mean to create a tempest in a teapot.  I was away from
> comp.lang.python, python-bugs, and python-dev for a few years.  In
> particular, I didn't ever see the aforementioned thread from Feb 2012.
>  Had I known of that thread I would have worded the sentence which
> shall not be repeated differently.
> 
> My apologies...

No problem, it's not about you specifically, it's just that some of us 
fans of % formatting can be a tad sensitive about it, especially since 
the idea that it has been deprecated (or soon will be deprecated, or one 
day will be deprecated, and therefore code using it is bad) is relatively 
widespread on the Internet.

Glad to have you back here!



-- 
Steven


From ned at nedbatchelder.com  Wed May 22 14:30:09 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Wed, 22 May 2013 14:30:09 -0400
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org>
	<mailman.1936.1369166040.3114.python-list@python.org>
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<519C3D99.5040107@gmail.com>
	<mailman.1958.1369219519.3114.python-list@python.org>
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <519D0EB1.3090207@nedbatchelder.com>


On 5/22/2013 10:58 AM, Steven D'Aprano wrote:
> On Wed, 22 May 2013 05:45:12 -0500, Skip Montanaro wrote:
>
>> I didn't mean to create a tempest in a teapot.  I was away from
>> comp.lang.python, python-bugs, and python-dev for a few years.  In
>> particular, I didn't ever see the aforementioned thread from Feb 2012.
>>   Had I known of that thread I would have worded the sentence which
>> shall not be repeated differently.
>>
>> My apologies...
> No problem, it's not about you specifically, it's just that some of us
> fans of % formatting can be a tad sensitive about it, especially since
> the idea that it has been deprecated (or soon will be deprecated, or one
> day will be deprecated, and therefore code using it is bad) is relatively
> widespread on the Internet.

Seems like maybe this should become a question in the Python FAQ.

--Ned.

>
> Glad to have you back here!
>
>
>



From pruebauno at latinmail.com  Wed May 22 16:26:23 2013
From: pruebauno at latinmail.com (nn)
Date: Wed, 22 May 2013 13:26:23 -0700 (PDT)
Subject: PEP 378: Format Specifier for Thousands Separator
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org>
	<mailman.1936.1369166040.3114.python-list@python.org>
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<519C3D99.5040107@gmail.com>
	<mailman.1958.1369219519.3114.python-list@python.org>
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1972.1369249307.3114.python-list@python.org>
Message-ID: <87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>

On May 22, 2:30?pm, Ned Batchelder <n... at nedbatchelder.com> wrote:
> On 5/22/2013 10:58 AM, Steven D'Aprano wrote:
>
> > On Wed, 22 May 2013 05:45:12 -0500, Skip Montanaro wrote:
>
> >> I didn't mean to create a tempest in a teapot. ?I was away from
> >> comp.lang.python, python-bugs, and python-dev for a few years. ?In
> >> particular, I didn't ever see the aforementioned thread from Feb 2012.
> >> ? Had I known of that thread I would have worded the sentence which
> >> shall not be repeated differently.
>
> >> My apologies...
> > No problem, it's not about you specifically, it's just that some of us
> > fans of % formatting can be a tad sensitive about it, especially since
> > the idea that it has been deprecated (or soon will be deprecated, or one
> > day will be deprecated, and therefore code using it is bad) is relatively
> > widespread on the Internet.
>
> Seems like maybe this should become a question in the Python FAQ.
>
> --Ned.
>
>
>
>
>
>
>
>
>
> > Glad to have you back here!

Maybe a cformat(formatstring, variables)  function should be created
in the string module so people who prefer that can use it. I don't
mind the C formatting syntax but I don't like the fact that the %
operator does something totally different when the first variable is
an integer and the fact that it misbehaves if the second variable is a
tuple.


From carlosnepomuceno at outlook.com  Wed May 22 18:31:20 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 01:31:20 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org>,
	<mailman.1936.1369166040.3114.python-list@python.org>,
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<519C3D99.5040107@gmail.com>,
	<mailman.1958.1369219519.3114.python-list@python.org>,
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.1972.1369249307.3114.python-list@python.org>,
	<87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>
Message-ID: <BLU176-W5166C8EC2BD8D8FF29207D7A90@phx.gbl>

----------------------------------------
> Date: Wed, 22 May 2013 13:26:23 -0700
> Subject: Re: PEP 378: Format Specifier for Thousands Separator
> From: pruebauno at latinmail.com
> To: python-list at python.org
[...]
>
> Maybe a cformat(formatstring, variables) function should be created
> in the string module so people who prefer that can use it. I don't
> mind the C formatting syntax but I don't like the fact that the %
> operator does something totally different when the first variable is
> an integer and the fact that it misbehaves if the second variable is a
> tuple.
> --
> http://mail.python.org/mailman/listinfo/python-list

I still don't understand why % benefits from literals optimization ("'%d'%12345") while '{:d}'.format(12345) doesn't.

What "totally different" you talking about? Please give me an example. 		 	   		  

From oscar.j.benjamin at gmail.com  Wed May 22 20:30:53 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 23 May 2013 01:30:53 +0100
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <BLU176-W5166C8EC2BD8D8FF29207D7A90@phx.gbl>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org>
	<mailman.1936.1369166040.3114.python-list@python.org>
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<519C3D99.5040107@gmail.com>
	<mailman.1958.1369219519.3114.python-list@python.org>
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1972.1369249307.3114.python-list@python.org>
	<87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>
	<BLU176-W5166C8EC2BD8D8FF29207D7A90@phx.gbl>
Message-ID: <CAHVvXxRN3znY4M5XDp=UObZ+Q9o9ZrrzA5pZbiz0fFR_7Zrqsw@mail.gmail.com>

On 22 May 2013 23:31, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
>
> I still don't understand why % benefits from literals optimization ("'%d'%12345") while '{:d}'.format(12345) doesn't.

There's no reason why that optimisation can't happen in principle.
However no one has written a patch for it. Why don't you look into
what it would take to make it happen?


Oscar


From carlosnepomuceno at outlook.com  Wed May 22 20:44:36 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 03:44:36 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <CAHVvXxRN3znY4M5XDp=UObZ+Q9o9ZrrzA5pZbiz0fFR_7Zrqsw@mail.gmail.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org>
	<mailman.1936.1369166040.3114.python-list@python.org>,
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<519C3D99.5040107@gmail.com>,
	<mailman.1958.1369219519.3114.python-list@python.org>
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.1972.1369249307.3114.python-list@python.org>
	<87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>,
	<BLU176-W5166C8EC2BD8D8FF29207D7A90@phx.gbl>,
	<CAHVvXxRN3znY4M5XDp=UObZ+Q9o9ZrrzA5pZbiz0fFR_7Zrqsw@mail.gmail.com>
Message-ID: <BLU176-W45FFC38AB12E7306B0B073D7AA0@phx.gbl>

----------------------------------------
> From: oscar.j.benjamin at gmail.com
> Date: Thu, 23 May 2013 01:30:53 +0100
> Subject: Re: PEP 378: Format Specifier for Thousands Separator
> To: carlosnepomuceno at outlook.com
> CC: pruebauno at latinmail.com; python-list at python.org
>
> On 22 May 2013 23:31, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
>>
>> I still don't understand why % benefits from literals optimization ("'%d'%12345") while '{:d}'.format(12345) doesn't.
>
> There's no reason why that optimisation can't happen in principle.
> However no one has written a patch for it. Why don't you look into
> what it would take to make it happen?
>
>
> Oscar

Maybe I'll look into that later, but I couldn't even find how the hell they made _Py_InsertThousandsGrouping() been called.

That's what I got when analysing % formating:

Thousands separator format specifier for str.__mod__()
======================================================

@Objects/stringobject.c: implements formatint() for '%' processing
-Looking for code used in str.format()

@Objects/stringlib/formatter.h: implements str.format()
-It uses STRINGLIB_GROUPING() to do the job.

@Objects/stringlib/stringdefs.h: #define STRINGLIB_GROUPING?????? _PyString_InsertThousandsGrouping
@Objects/stringlib/unicodedefs.h: #define STRINGLIB_GROUPING?????? _PyUnicode_InsertThousandsGrouping
@Objects/stringobject.c: #define _Py_InsertThousandsGrouping _PyString_InsertThousandsGrouping
@Objects/stringobject.h: declares _PyString_InsertThousandsGrouping()
@???: ??? _PyString_InsertThousandsGrouping ??? _Py_InsertThousandsGrouping
@Objects/stringlib/localeutil.h: implements _Py_InsertThousandsGrouping()


Let me explain what that means. I found no relating declarations/definitions that turn _PyString_InsertThousandsGrouping into _Py_InsertThousandsGrouping.

So, I don't even know how that source code compiles without error.

:/ really strange...


Not to mention the lots of code inside header definition files! Weird!!!! 		 	   		  

From pruebauno at latinmail.com  Thu May 23 09:44:05 2013
From: pruebauno at latinmail.com (nn)
Date: Thu, 23 May 2013 06:44:05 -0700 (PDT)
Subject: PEP 378: Format Specifier for Thousands Separator
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>, 
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org>,
	<mailman.1936.1369166040.3114.python-list@python.org>, 
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<519C3D99.5040107@gmail.com>, 
	<mailman.1958.1369219519.3114.python-list@python.org>,
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>, 
	<mailman.1972.1369249307.3114.python-list@python.org>,
	<87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>
	<mailman.1977.1369261949.3114.python-list@python.org>
Message-ID: <b8623121-631a-4464-bd23-0e210018de78@e13g2000yqp.googlegroups.com>

On May 22, 6:31?pm, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
wrote:
> ----------------------------------------
>
> > Date: Wed, 22 May 2013 13:26:23 -0700
> > Subject: Re: PEP 378: Format Specifier for Thousands Separator
> > From: prueba... at latinmail.com
> > To: python-l... at python.org
> [...]
>
> > Maybe a cformat(formatstring, variables) function should be created
> > in the string module so people who prefer that can use it. I don't
> > mind the C formatting syntax but I don't like the fact that the %
> > operator does something totally different when the first variable is
> > an integer and the fact that it misbehaves if the second variable is a
> > tuple.
> > --
> >http://mail.python.org/mailman/listinfo/python-list
>
> I still don't understand why % benefits from literals optimization ("'%d'%12345") while '{:d}'.format(12345) doesn't.
>
> What "totally different" you talking about? Please give me an example.

>>> def eggs(spam, ham): return spam % ham

>>> def milk(beef, steak): return beef.format(steak)

>>> a='%s'
>>> c=9
>>> d=4
>>> e=[1,2]
>>> f=(3,5)
>>> d='{}'

>>> eggs(a,4)
'4'
>>> eggs(c,4)
1
>>> eggs(a,e)
'[1, 2]'
>>> eggs(a,f)
Traceback (most recent call last):
  File "<pyshell#29>", line 1, in <module>
    eggs(a,f)
  File "<pyshell#1>", line 1, in eggs
    def eggs(spam, ham): return spam % ham
TypeError: not all arguments converted during string formatting
>>> '%s'%(5%3)
'2'

>>> milk(d,4)
'4'
>>> milk(c,4)
Traceback (most recent call last):
  File "<pyshell#53>", line 1, in <module>
    milk(c,4)
  File "<pyshell#49>", line 1, in milk
    def milk(beef, steak): return beef.format(steak)
AttributeError: 'int' object has no attribute 'format'
>>> milk(d,e)
'[1, 2]'
>>> milk(d,f)
'(3, 5)'
>>> '{}'.format(5%3)
'2'



From carlosnepomuceno at outlook.com  Thu May 23 11:26:49 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 18:26:49 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <b8623121-631a-4464-bd23-0e210018de78@e13g2000yqp.googlegroups.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>, ,
	<nad-F52CE7.22440720052013@news.gmane.org>, ,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	, <BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>, ,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	, <knghok$3bd$1@ger.gmane.org>, ,
	<mailman.1936.1369166040.3114.python-list@python.org>, ,
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>, ,
	<519C3D99.5040107@gmail.com>, ,
	<mailman.1958.1369219519.3114.python-list@python.org>, ,
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>, ,
	<mailman.1972.1369249307.3114.python-list@python.org>, ,
	<87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>,
	<mailman.1977.1369261949.3114.python-list@python.org>,
	<b8623121-631a-4464-bd23-0e210018de78@e13g2000yqp.googlegroups.com>
Message-ID: <BLU176-W35FCA0F6068A230026ED88D7AA0@phx.gbl>

----------------------------------------
> Date: Thu, 23 May 2013 06:44:05 -0700
> Subject: Re: PEP 378: Format Specifier for Thousands Separator
> From: pruebauno at latinmail.com
> To: python-list at python.org
[...]
>>>> eggs(a,f)
> Traceback (most recent call last):
> File "<pyshell#29>", line 1, in <module>
> eggs(a,f)
> File "<pyshell#1>", line 1, in eggs
> def eggs(spam, ham): return spam % ham
> TypeError: not all arguments converted during string formatting
>>>> '%s'%(5%3)
> '2'

So % doesn't handle tuples! Why's that? Is it intentional (by design)? 		 	   		  

From davea at davea.name  Thu May 23 14:42:47 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 23 May 2013 14:42:47 -0400
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <BLU176-W35FCA0F6068A230026ED88D7AA0@phx.gbl>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>, ,
	<nad-F52CE7.22440720052013@news.gmane.org>, ,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	, <BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>, ,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	, <knghok$3bd$1@ger.gmane.org>, ,
	<mailman.1936.1369166040.3114.python-list@python.org>, ,
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>, ,
	<519C3D99.5040107@gmail.com>, ,
	<mailman.1958.1369219519.3114.python-list@python.org>, ,
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>, ,
	<mailman.1972.1369249307.3114.python-list@python.org>, ,
	<87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>,
	<mailman.1977.1369261949.3114.python-list@python.org>,
	<b8623121-631a-4464-bd23-0e210018de78@e13g2000yqp.googlegroups.com>
	<BLU176-W35FCA0F6068A230026ED88D7AA0@phx.gbl>
Message-ID: <519E6327.8070204@davea.name>

On 05/23/2013 11:26 AM, Carlos Nepomuceno wrote:
> ----------------------------------------
>> Date: Thu, 23 May 2013 06:44:05 -0700
>> Subject: Re: PEP 378: Format Specifier for Thousands Separator
>> From: pruebauno at latinmail.com
>> To: python-list at python.org
> [...]

You left out the part where a and f are initialized:


 >>> a='%s'
 >>> f=(3,5)


>>>>> eggs(a,f)
>> Traceback (most recent call last):
>> File "<pyshell#29>", line 1, in <module>
>> eggs(a,f)
>> File "<pyshell#1>", line 1, in eggs
>> def eggs(spam, ham): return spam % ham
>> TypeError: not all arguments converted during string formatting
>>>>> '%s'%(5%3)
>> '2'
>
> So % doesn't handle tuples! Why's that? Is it intentional (by design)? 		 	   		
>

It's a conflict in the design.  A tuple is used to supply multiple 
arguments to the % operator.  So if you want to have a tuple as the 
first argument, you need to enclose it in another tuple.

try the following:

print a % (f,)

The trouble is, it doesn't generalize very readily, so it's difficult to 
use in a function like eggs()

-- 
DaveA


From tjreedy at udel.edu  Thu May 23 16:19:33 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Thu, 23 May 2013 16:19:33 -0400
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <519E6327.8070204@davea.name>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>, ,
	<nad-F52CE7.22440720052013@news.gmane.org>, ,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	, <BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>, ,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	, <knghok$3bd$1@ger.gmane.org>, ,
	<mailman.1936.1369166040.3114.python-list@python.org>, ,
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>, ,
	<519C3D99.5040107@gmail.com>, ,
	<mailman.1958.1369219519.3114.python-list@python.org>, ,
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>, ,
	<mailman.1972.1369249307.3114.python-list@python.org>, ,
	<87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>,
	<mailman.1977.1369261949.3114.python-list@python.org>,
	<b8623121-631a-4464-bd23-0e210018de78@e13g2000yqp.googlegroups.com>
	<BLU176-W35FCA0F6068A230026ED88D7AA0@phx.gbl>
	<519E6327.8070204@davea.name>
Message-ID: <knltkb$6b1$1@ger.gmane.org>

On 5/23/2013 2:42 PM, Dave Angel wrote:
> On 05/23/2013 11:26 AM, Carlos Nepomuceno wrote:

>
>>>>>> eggs(a,f)
>>> Traceback (most recent call last):
>>> File "<pyshell#29>", line 1, in <module>
>>> eggs(a,f)
>>> File "<pyshell#1>", line 1, in eggs
>>> def eggs(spam, ham): return spam % ham
>>> TypeError: not all arguments converted during string formatting
>>>>>> '%s'%(5%3)
>>> '2'
>>
>> So % doesn't handle tuples! Why's that? Is it intentional (by design)?
>>
>
> It's a conflict in the design.  A tuple is used to supply multiple
> arguments to the % operator.  So if you want to have a tuple as the
> first argument, you need to enclose it in another tuple.

The problem is that interpolating 1 to many items into a string is *not* 
a binary operation. The needed hack to pretend that it is, using a tuple 
to represent multiple items rather than just itself, was one of the 
reasons for making string formatting a honest function, where multiple 
items to be formatted are passed as multiple arguments.




From carlosnepomuceno at outlook.com  Thu May 23 18:20:26 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 24 May 2013 01:20:26 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <knltkb$6b1$1@ger.gmane.org>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	,,<nad-F52CE7.22440720052013@news.gmane.org>,
	, , <CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	, , <BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	, , <CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	, , <knghok$3bd$1@ger.gmane.org>,
	,,<mailman.1936.1369166040.3114.python-list@python.org>,
	,,<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	,,<519C3D99.5040107@gmail.com>,
	,,<mailman.1958.1369219519.3114.python-list@python.org>,
	,,<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	,,<mailman.1972.1369249307.3114.python-list@python.org>,
	, , <87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>, ,
	<mailman.1977.1369261949.3114.python-list@python.org>, ,
	<b8623121-631a-4464-bd23-0e210018de78@e13g2000yqp.googlegroups.com>,
	<BLU176-W35FCA0F6068A230026ED88D7AA0@phx.gbl>,
	<519E6327.8070204@davea.name>, <knltkb$6b1$1@ger.gmane.org>
Message-ID: <BLU176-W36CA0353E5678F8D03AC6AD7AA0@phx.gbl>

----------------------------------------
> To: python-list at python.org
> From: tjreedy at udel.edu
[...]
>> It's a conflict in the design. A tuple is used to supply multiple
>> arguments to the % operator. So if you want to have a tuple as the
>> first argument, you need to enclose it in another tuple.
>
> The problem is that interpolating 1 to many items into a string is *not*
> a binary operation. The needed hack to pretend that it is, using a tuple
> to represent multiple items rather than just itself, was one of the
> reasons for making string formatting a honest function, where multiple
> items to be formatted are passed as multiple arguments.

Thanks so much guys! Now I understand why some people hate %-formatting!

I don't think that's a problem because there's no format specifier for tuples in the %-formatting definition[1].
So it's up to the user to make the necessary conversion.

I still love the %-formatting style!

Can str.format() do the following?

f = '%d %d %d'
v = '1,2,3'
print f % eval(v)

If yes, how?


[1] http://docs.python.org/2/library/stdtypes.html#string-formatting 		 	   		  

From malaclypse2 at gmail.com  Thu May 23 21:17:54 2013
From: malaclypse2 at gmail.com (Jerry Hill)
Date: Thu, 23 May 2013 21:17:54 -0400
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <BLU176-W36CA0353E5678F8D03AC6AD7AA0@phx.gbl>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>
	<nad-F52CE7.22440720052013@news.gmane.org>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>
	<knghok$3bd$1@ger.gmane.org>
	<mailman.1936.1369166040.3114.python-list@python.org>
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<519C3D99.5040107@gmail.com>
	<mailman.1958.1369219519.3114.python-list@python.org>
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<mailman.1972.1369249307.3114.python-list@python.org>
	<87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>
	<mailman.1977.1369261949.3114.python-list@python.org>
	<b8623121-631a-4464-bd23-0e210018de78@e13g2000yqp.googlegroups.com>
	<BLU176-W35FCA0F6068A230026ED88D7AA0@phx.gbl>
	<519E6327.8070204@davea.name> <knltkb$6b1$1@ger.gmane.org>
	<BLU176-W36CA0353E5678F8D03AC6AD7AA0@phx.gbl>
Message-ID: <CADwdpyafzQ5ZVpASszmCxX=CDsSmymDov7gj48Wp3AT1DiJDTQ@mail.gmail.com>

On Thu, May 23, 2013 at 6:20 PM, Carlos Nepomuceno <
carlosnepomuceno at outlook.com> wrote:

> Can str.format() do the following?
>
> f = '%d %d %d'
> v = '1,2,3'
> print f % eval(v)
>

?Sure:

Python 3.2.2 (default, Sep  4 2011, 09:51:08) [MSC v.1500 32 bit (Intel)]
on win32
>>> f = "{} {} {}"
>>> v = "1,2,3"
>>> print(f.format(*eval(v)))
1 2 3
>>>

The * unpacks the tuple returned from eval(), so that you get 3 separate
parameters passed to format(), instead of the single tuple.?

--
?
Jerry?
-------------- next part --------------
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From carlosnepomuceno at outlook.com  Thu May 23 21:41:22 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 24 May 2013 04:41:22 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <CADwdpyafzQ5ZVpASszmCxX=CDsSmymDov7gj48Wp3AT1DiJDTQ@mail.gmail.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	<nad-F52CE7.22440720052013@news.gmane.org>,
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<BLU176-W9FF52BDCE42DAF40E6AC7D7A80@phx.gbl>,
	<CANc-5UyWuCd+roRt5V5aocx0vEc1TXfDnG2-phy_gAKSRaqOBA@mail.gmail.com>,
	<knghok$3bd$1@ger.gmane.org>,
	<mailman.1936.1369166040.3114.python-list@python.org>,
	<519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<519C3D99.5040107@gmail.com>,
	<mailman.1958.1369219519.3114.python-list@python.org>,
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.1972.1369249307.3114.python-list@python.org>,
	<87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>,
	<mailman.1977.1369261949.3114.python-list@python.org>,
	<b8623121-631a-4464-bd23-0e210018de78@e13g2000yqp.googlegroups.com>,
	<BLU176-W35FCA0F6068A230026ED88D7AA0@phx.gbl>,
	<519E6327.8070204@davea.name>, <knltkb$6b1$1@ger.gmane.org>,
	<BLU176-W36CA0353E5678F8D03AC6AD7AA0@phx.gbl>,
	<CADwdpyafzQ5ZVpASszmCxX=CDsSmymDov7gj48Wp3AT1DiJDTQ@mail.g
	mail.com>
Message-ID: <BLU176-W9AFCFD691D186D2B52265D7AB0@phx.gbl>

Thank you! Hail Eris!!! :)

________________________________
> Date: Thu, 23 May 2013 21:17:54 -0400 
> Subject: Re: PEP 378: Format Specifier for Thousands Separator 
> From: malaclypse2 at gmail.com 
> To: carlosnepomuceno at outlook.com 
> CC: python-list at python.org 
>  
> On Thu, May 23, 2013 at 6:20 PM, Carlos Nepomuceno  
> <carlosnepomuceno at outlook.com<mailto:carlosnepomuceno at outlook.com>>  
> wrote: 
> Can str.format() do the following? 
>  
> f = '%d %d %d' 
> v = '1,2,3' 
> print f % eval(v) 
>  
> ?Sure: 
>  
> Python 3.2.2 (default, Sep  4 2011, 09:51:08) [MSC v.1500 32 bit  
> (Intel)] on win32 
> >>> f = "{} {} {}" 
> >>> v = "1,2,3" 
> >>> print(f.format(*eval(v))) 
> 1 2 3 
> >>> 
>  
> The * unpacks the tuple returned from eval(), so that you get 3  
> separate parameters passed to format(), instead of the single tuple.? 
>  
> -- 
> ? 
> Jerry? 
> 		 	   		  

From pruebauno at latinmail.com  Fri May 24 09:50:51 2013
From: pruebauno at latinmail.com (nn)
Date: Fri, 24 May 2013 06:50:51 -0700 (PDT)
Subject: PEP 378: Format Specifier for Thousands Separator
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>, ,
	<knghok$3bd$1@ger.gmane.org>, ,
	<mailman.1936.1369166040.3114.python-list@python.org>, 
	, <519c348a$0$6599$c3e8da3$5496439d@news.astraweb.com>, ,
	<519C3D99.5040107@gmail.com>, 
	, <mailman.1958.1369219519.3114.python-list@python.org>, ,
	<519cdcff$0$6599$c3e8da3$5496439d@news.astraweb.com>, ,
	<mailman.1972.1369249307.3114.python-list@python.org>, 
	, <87eaaf24-df6a-4f6b-b873-16ca96c12e24@b2g2000yqe.googlegroups.com>,
	<mailman.1977.1369261949.3114.python-list@python.org>,
	<b8623121-631a-4464-bd23-0e210018de78@e13g2000yqp.googlegroups.com>
	<BLU176-W35FCA0F6068A230026ED88D7AA0@phx.gbl>
	<mailman.2028.1369334586.3114.python-list@python.org>
Message-ID: <3d927c74-a4ce-4d02-a107-443d059c32a3@s18g2000yqg.googlegroups.com>

On May 23, 2:42?pm, Dave Angel <da... at davea.name> wrote:
> On 05/23/2013 11:26 AM, Carlos Nepomuceno wrote:
>
> > ----------------------------------------
> >> Date: Thu, 23 May 2013 06:44:05 -0700
> >> Subject: Re: PEP 378: Format Specifier for Thousands Separator
> >> From: prueba... at latinmail.com
> >> To: python-l... at python.org
> > [...]
>
> You left out the part where a and f are initialized:
>
> ?>>> a='%s'
> ?>>> f=(3,5)
>
> >>>>> eggs(a,f)
> >> Traceback (most recent call last):
> >> File "<pyshell#29>", line 1, in <module>
> >> eggs(a,f)
> >> File "<pyshell#1>", line 1, in eggs
> >> def eggs(spam, ham): return spam % ham
> >> TypeError: not all arguments converted during string formatting
> >>>>> '%s'%(5%3)
> >> '2'
>
> > So % doesn't handle tuples! Why's that? Is it intentional (by design)?
>
> It's a conflict in the design. ?A tuple is used to supply multiple
> arguments to the % operator. ?So if you want to have a tuple as the
> first argument, you need to enclose it in another tuple.
>
> try the following:
>
> print a % (f,)
>
> The trouble is, it doesn't generalize very readily, so it's difficult to
> use in a function like eggs()
>
> --
> DaveA

It's all there, it's just that quoting ate it. Let's try this again:

>>> def eggs(spam, ham): return spam % ham
>>> def milk(beef, steak): return beef.format(steak)
>>> a='%s'
>>> c=9
>>> d=4
>>> e=[1,2]
>>> f=(3,5)
>>> d='{}'
>>> eggs(a,4)
'4'
>>> eggs(c,4)
1
>>> eggs(a,e)
'[1, 2]'
>>> eggs(a,f)

Traceback (most recent call last):
  File "<pyshell#29>", line 1, in <module>
    eggs(a,f)
  File "<pyshell#1>", line 1, in eggs
    def eggs(spam, ham): return spam % ham
TypeError: not all arguments converted during string formatting
>>> '%s'%(5%3)
'2'

>>> milk(d,4)
'4'
>>> milk(c,4)

Traceback (most recent call last):
  File "<pyshell#53>", line 1, in <module>
    milk(c,4)
  File "<pyshell#49>", line 1, in milk
    def milk(beef, steak): return beef.format(steak)
AttributeError: 'int' object has no attribute 'format'
>>> milk(d,e)
'[1, 2]'
>>> milk(d,f)
'(3, 5)'
>>> '{}'.format(5%3)
'2'

The three issues represented:
1. Functions in which both values of the operator are parameters might
not return a string but an integer instead. It is not always
immediately obvious when reading such functions if modulus or
formatting is intended.
2. Function doesn't handle tuple properly unless carefully written
3. Too much % noise because % is used for 3 things: the special
placeholder character inside format strings, the format operator and
the modulus operator.


From dihedral88888 at gmail.com  Thu May 23 22:29:14 2013
From: dihedral88888 at gmail.com (88888 Dihedral)
Date: Thu, 23 May 2013 19:29:14 -0700 (PDT)
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <mailman.1929.1369162176.3114.python-list@python.org>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,>
	<nad-F52CE7.22440720052013@news.gmane.org>,
	> <CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>
	<mailman.1929.1369162176.3114.python-list@python.org>
Message-ID: <b87bfa97-e0cc-489e-847b-02d9312060bd@googlegroups.com>

Carlos Nepomuceno? 2013?5?22????UTC+8??2?49?28????
> ________________________________
> > From: alyssonbruno at gmail.com 
> > Date: Tue, 21 May 2013 09:03:13 -0300 
> > Subject: Re: PEP 378: Format Specifier for Thousands Separator 
> > To: python-list at python.org 
> >  
> > This work in 3.1+: 
> >  
> > $ python3 
> > Python 3.1.3 (r313:86834, Nov 28 2010, 11:28:10) 
> > [GCC 4.4.5] on linux2 
> > Type "help", "copyright", "credits" or "license" for more information. 
> > >>> one_number = 1234567 
> > >>> print('number={:,}'.format(one_number)) 
> > number=1,234,567 
> > >>> 
> >  
> 
> Thank you, but let me rephrase it. I'm already using str.format() but I'd like to use '%' (BINARY_MODULO) operator instead.
> 
> I've looked into the source code of CPython 2.7.5 and I've found no evidence of the thousands separator been implemented on formatint() in "Objects/unicodeobject.c".
> 
> I also didn't find the _PyString_FormatLong() used in formatlong(). Where is _PyString_FormatLong() located?
> 
> So, the question is: Where would I change the CPython 2.7.5 source code to enable '%' (BINARY_MODULO) to format using the thousands separator like str.format() does, such as:
> 
> >>>sys.stderr.write('%,d\n' % 1234567)
> 1,234,567

Could a separate instance like the  I/O device of a subprocess
to be easily available in Python?

The next question would be whether the flow of several I/O data streams could be easily piped and manipulated in the high level
programming designs without consuming too much resources.







From carlosnepomuceno at outlook.com  Fri May 24 11:25:45 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 24 May 2013 18:25:45 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <b87bfa97-e0cc-489e-847b-02d9312060bd@googlegroups.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>, >,
	<nad-F52CE7.22440720052013@news.gmane.org>, , >
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<mailman.1929.1369162176.3114.python-list@python.org>,
	<b87bfa97-e0cc-489e-847b-02d9312060bd@googlegroups.com>
Message-ID: <BLU176-W781D477CDE6E814C7EABCD7AB0@phx.gbl>

----------------------------------------
> Date: Thu, 23 May 2013 19:29:14 -0700
> Subject: Re: PEP 378: Format Specifier for Thousands Separator
> From: dihedral88888 at gmail.com
[...]
> Could a separate instance like the I/O device of a subprocess
> to be easily available in Python?
>
> The next question would be whether the flow of several I/O data streams could be easily piped and manipulated in the high level
> programming designs without consuming too much resources.


I'm sorry but I don't understand your question.

Do you mean returning the output of another process to the caller? Like:

import subprocess
output = subprocess.check_output(['ping', 'google.com']) 		 	   		  

From andipersti at gmail.com  Fri May 24 13:28:29 2013
From: andipersti at gmail.com (Andreas Perstinger)
Date: Fri, 24 May 2013 19:28:29 +0200
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <BLU176-W781D477CDE6E814C7EABCD7AB0@phx.gbl>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>, >,
	<nad-F52CE7.22440720052013@news.gmane.org>, ,
	> <CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>,
	<mailman.1929.1369162176.3114.python-list@python.org>,
	<b87bfa97-e0cc-489e-847b-02d9312060bd@googlegroups.com>
	<BLU176-W781D477CDE6E814C7EABCD7AB0@phx.gbl>
Message-ID: <519FA33D.5030209@gmail.com>

On 24.05.2013 17:25, Carlos Nepomuceno wrote:
> ----------------------------------------
>> Date: Thu, 23 May 2013 19:29:14 -0700
>> Subject: Re: PEP 378: Format Specifier for Thousands Separator
>> From: dihedral88888 at gmail.com
>> [some typical dihedral stuff]
>
> I'm sorry but I don't understand your question.

Don't worry. I guess most people on this list don't understand it either.

It looks like dihedral is a bot although nobody knows for sure. Search 
for some other posts from him/her/it in the archive and form your own 
opinion.

IMHO you can simply ignore him/her/it.

Bye, Andreas



From carlosnepomuceno at outlook.com  Fri May 24 17:07:41 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 00:07:41 +0300
Subject: PEP 378: Format Specifier for Thousands Separator
In-Reply-To: <519FA33D.5030209@gmail.com>
References: <BLU176-W10190CB892A0414C988A05D7A80@phx.gbl>,
	>,,<nad-F52CE7.22440720052013@news.gmane.org>, ,,>
	<CADUW+M=Y7b=4ZEENVzx4p6YpVD8T0eG=qz7sz8+iEow-5-o+jQ@mail.gmail.com>, ,
	<mailman.1929.1369162176.3114.python-list@python.org>, ,
	<b87bfa97-e0cc-489e-847b-02d9312060bd@googlegroups.com>,
	<BLU176-W781D477CDE6E814C7EABCD7AB0@phx.gbl>,
	<519FA33D.5030209@gmail.com>
Message-ID: <BLU176-W12DC0E6CBECC9F049D8074D7AB0@phx.gbl>

lol that reminds me of George! lol
;)

----------------------------------------
> Date: Fri, 24 May 2013 19:28:29 +0200
> From: andipersti at gmail.com
> To: python-list at python.org
> Subject: Re: PEP 378: Format Specifier for Thousands Separator
>
> On 24.05.2013 17:25, Carlos Nepomuceno wrote:
>> ----------------------------------------
>>> Date: Thu, 23 May 2013 19:29:14 -0700
>>> Subject: Re: PEP 378: Format Specifier for Thousands Separator
>>> From: dihedral88888 at gmail.com
>>> [some typical dihedral stuff]
>>
>> I'm sorry but I don't understand your question.
>
> Don't worry. I guess most people on this list don't understand it either.
>
> It looks like dihedral is a bot although nobody knows for sure. Search
> for some other posts from him/her/it in the archive and form your own
> opinion.
>
> IMHO you can simply ignore him/her/it.
>
> Bye, Andreas
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From steve+comp.lang.python at pearwood.info  Tue May 21 04:26:14 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 21 May 2013 08:26:14 GMT
Subject: sympy.nsimplify
Message-ID: <519b2fa6$0$6574$c3e8da3$5496439d@news.astraweb.com>

For maths nerds like me, this is too cool for words:

http://www.johndcook.com/blog/2013/04/30/recognizing-numbers/



-- 
Steven


From rosuav at gmail.com  Tue May 21 05:08:05 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 21 May 2013 19:08:05 +1000
Subject: sympy.nsimplify
In-Reply-To: <519b2fa6$0$6574$c3e8da3$5496439d@news.astraweb.com>
References: <519b2fa6$0$6574$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmrJFy-UmqO5m5zALA0MRRvsCBvAPJnPR2AQ8cxT9jT23A@mail.gmail.com>

On Tue, May 21, 2013 at 6:26 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> For maths nerds like me, this is too cool for words:
>
> http://www.johndcook.com/blog/2013/04/30/recognizing-numbers/

It is indeed, very cool. I think I need to conjure an excuse to use
this someplace.

ChrisA


From skip at pobox.com  Tue May 21 07:01:40 2013
From: skip at pobox.com (Skip Montanaro)
Date: Tue, 21 May 2013 06:01:40 -0500
Subject: sympy.nsimplify
In-Reply-To: <CAPTjJmrJFy-UmqO5m5zALA0MRRvsCBvAPJnPR2AQ8cxT9jT23A@mail.gmail.com>
References: <519b2fa6$0$6574$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmrJFy-UmqO5m5zALA0MRRvsCBvAPJnPR2AQ8cxT9jT23A@mail.gmail.com>
Message-ID: <CANc-5UzHDok44p+YMxbWNtyZ0Q+5i9PKLy2HKkow3gmnELDZ2g@mail.gmail.com>

Very cool indeed.  In the comments was a link to an XKCD cartoon.  Its
tool tip mentioned "twin primes".  Looked that up.  Google pointed (of
course) at Wikipedia.  Read that.  Backed up to the Google Search, and
noticed there is a news item from 15 hours ago that an unknown
mathematician at the University of New Hampshire has proven the twin
primes conjecture:
http://www.wired.com/wiredscience/2013/05/twin-primes/

This is nothing to do with the original post.  It's just amazing to me
how short the distance between one very interesting topic on the net
and something almost unrelated can be.

Skip


From paul.nospam at rudin.co.uk  Tue May 21 07:17:24 2013
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Tue, 21 May 2013 12:17:24 +0100
Subject: sympy.nsimplify
References: <519b2fa6$0$6574$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmrJFy-UmqO5m5zALA0MRRvsCBvAPJnPR2AQ8cxT9jT23A@mail.gmail.com>
	<mailman.1920.1369134110.3114.python-list@python.org>
Message-ID: <87hahweg57.fsf@no-fixed-abode.cable.virginmedia.net>

Skip Montanaro <skip at pobox.com> writes:

> Very cool indeed.  In the comments was a link to an XKCD cartoon.  Its
> tool tip mentioned "twin primes".  Looked that up.  Google pointed (of
> course) at Wikipedia.  Read that.  Backed up to the Google Search, and
> noticed there is a news item from 15 hours ago that an unknown
> mathematician at the University of New Hampshire has proven the twin
> primes conjecture:
> http://www.wired.com/wiredscience/2013/05/twin-primes/
>
> This is nothing to do with the original post.  It's just amazing to me
> how short the distance between one very interesting topic on the net
> and something almost unrelated can be.

AIUI the twin primes conjecture hasn't been proved. But a significant
related fact - that there's an infinitude of primes no more that N apart
where N <~ 70,000,000. That might not sound like a lot of progress - but
the point is that the existence of some finite bound is very
significant.


From iman.memarpour at gmail.com  Tue May 21 04:38:37 2013
From: iman.memarpour at gmail.com (iman.memarpour at gmail.com)
Date: Tue, 21 May 2013 01:38:37 -0700 (PDT)
Subject: please help
Message-ID: <649f272e-022b-4a11-8431-2098aa299d7b@googlegroups.com>

WAP in python to accept a list of words on STDIN and searches for a line containing all five vowels(a,e,i,o,u)


From rosuav at gmail.com  Tue May 21 05:05:25 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 21 May 2013 19:05:25 +1000
Subject: please help
In-Reply-To: <649f272e-022b-4a11-8431-2098aa299d7b@googlegroups.com>
References: <649f272e-022b-4a11-8431-2098aa299d7b@googlegroups.com>
Message-ID: <CAPTjJmrN0LjM1T8029KwiD4bpp=GJBmhVwiyaQGDbVsYMg0ggw@mail.gmail.com>

On Tue, May 21, 2013 at 6:38 PM,  <iman.memarpour at gmail.com> wrote:
> WAP in python to accept a list of words on STDIN and searches for a line containing all five vowels(a,e,i,o,u)

Homework.

Have a shot at it yourself, post your code, show that you can put in
some effort. Otherwise we won't see much reason to put in effort for
you.

ChrisA


From breamoreboy at yahoo.co.uk  Tue May 21 05:07:41 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 21 May 2013 10:07:41 +0100
Subject: please help
In-Reply-To: <649f272e-022b-4a11-8431-2098aa299d7b@googlegroups.com>
References: <649f272e-022b-4a11-8431-2098aa299d7b@googlegroups.com>
Message-ID: <knfdg0$vn5$1@ger.gmane.org>

On 21/05/2013 09:38, iman.memarpour at gmail.com wrote:
> WAP in python to accept a list of words on STDIN and searches for a line containing all five vowels(a,e,i,o,u)
>

Sorry we don't do your homework for you.  But your starter for 10 is to 
use raw_input on Python 2 or input on Python 3 to fetch data from stdin. 
  I look forward to reviewing your code.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From maciej at opencsw.org  Tue May 21 05:51:48 2013
From: maciej at opencsw.org (=?UTF-8?Q?Maciej_=28Matchek=29_Blizi=C5=84ski?=)
Date: Tue, 21 May 2013 10:51:48 +0100
Subject: 64-bit Python for Solaris
Message-ID: <CALtRa-59UwUSXWVAMYuetZYLpHOF=M=ttjOCfiCc9YhWHMKRhw@mail.gmail.com>

Hello python-list,

I'm looking into creating a 32/64-bit Python (2.x and/or 3.x) package
for Solaris. The specificity of that package is that I need to include
both 32-bit and 64-bit binaries in it. The exact way in which the
32/64 support is done is described at [1].

There currently is a Python package that I maintain, which is 32-bit only[2].

I have made an attempt to build a 64-bit package, and my findings are
that the ${prefix}/lib/pythonX.Y/_sysconfigdata.py file contains
system-specific information. Note that it's not ${libdir}/pythonX.Y -
that would have worked, because I'm specifying different ${libdir}
directories when running the 32-bit and 64-bit builds. The Python
installer specifically uses ${prefix}/lib/pythonX.Y. For the most part
is fine, because most of files in there are not architecture-specific,
and it would be quite good to share them among the 32-bit and 64-bit
binaries at runtime. The problem is that some files differ. I've
described it some more at [3].

Ideally, I'd make _sysconfigdata.py return/set different values
depending on the Python runtime that reads it. Something like:

if we're 64-bit:
  set values for the 64-bit platform
else:
  set values for the 32-bit platform

It's a similar approach to how we currently handle C header files. See
the 'Development packages' section in [1] for more information.

The problem is that it would involve somewhat intrusive patching of
the Python source code, and in long term that means maintainability
issues.

Has this issue been seen before? Is there a better solution? Is there
something that can be done upstream to accommodate this kind of
packaging?

Maciej

[1] http://www.opencsw.org/manual/for-maintainers/32-bit-and-64-bit.html
[2] http://www.opencsw.org/packages/python/
[3] http://lists.opencsw.org/pipermail/maintainers/2013-January/017583.html


From maciej at opencsw.org  Mon May 27 14:28:09 2013
From: maciej at opencsw.org (=?UTF-8?Q?Maciej_=28Matchek=29_Blizi=C5=84ski?=)
Date: Mon, 27 May 2013 19:28:09 +0100
Subject: 64-bit Python for Solaris
In-Reply-To: <CALtRa-59UwUSXWVAMYuetZYLpHOF=M=ttjOCfiCc9YhWHMKRhw@mail.gmail.com>
References: <CALtRa-59UwUSXWVAMYuetZYLpHOF=M=ttjOCfiCc9YhWHMKRhw@mail.gmail.com>
Message-ID: <CALtRa-6mzMm6DQaz7+v0x4BBVZOiaXje+vqZAZHS-EfQEDuDDQ@mail.gmail.com>

<Crickets>

2013/5/21 Maciej (Matchek) Blizi?ski <maciej at opencsw.org>:
> the ${prefix}/lib/pythonX.Y/_sysconfigdata.py file contains
> system-specific information

...and is installed in an architecture-independent directory by the
Python installer. This looks broken to me.


From kobewka at gmail.com  Tue May 21 09:12:31 2013
From: kobewka at gmail.com (kobewka at gmail.com)
Date: Tue, 21 May 2013 06:12:31 -0700 (PDT)
Subject: Static Maps from Lat Long data in XLS file
Message-ID: <d58b4b5f-1b65-48b4-811f-fd81f1c019fe@googlegroups.com>

Hello,

I'm new to Python, but I think it can solve my problem and I am looking for a someone to point me to tutorial or give me some tips here.

I have an xls file that has about 1,000 latitude and longitude points. I want to do one of two things: 1) Save a static maps and street view image from the coordinates, or 2) create an html file with the map and street view image side by side.

I need the urls to look like this: 

Map with a pin in the centre:
http://maps.googleapis.com/maps/api/staticmap?center=43.65162,-79.40571&zoom=16&size=600x600&markers=color:blue%7Clabel:S%7C43.65162,-79.40571&sensor=false

Image:
http://maps.googleapis.com/maps/api/streetview?location=43.65162,%20-79.40571&size=600x600&sensor=false

I am not sure if option 1 will work because the url doesn't actually lead to an image, but rather Google returns an image when that url is used. 

Any tips or pointers are much appreciated!


From ken at bscientific.net  Tue May 21 09:58:25 2013
From: ken at bscientific.net (Ken Bolton)
Date: Tue, 21 May 2013 09:58:25 -0400
Subject: Static Maps from Lat Long data in XLS file
In-Reply-To: <d58b4b5f-1b65-48b4-811f-fd81f1c019fe@googlegroups.com>
References: <d58b4b5f-1b65-48b4-811f-fd81f1c019fe@googlegroups.com>
Message-ID: <CAN7ek0NrO+=s8BrWh-WM0gFTsC2odE6O7oOdO6LZuvVAvEbOYw@mail.gmail.com>

On Tue, May 21, 2013 at 9:12 AM, <kobewka at gmail.com> wrote:

> Hello,
>
> I'm new to Python, but I think it can solve my problem and I am looking
> for a someone to point me to tutorial or give me some tips here.
>

Hi! I am a first-time poster to python-list, but I think I can help you.


> I have an xls file that has about 1,000 latitude and longitude points. I
> want to do one of two things: 1) Save a static maps and street view image
> from the coordinates, or 2) create an html file with the map and street
> view image side by side.


If you save your xls file as a csv (comma-separated values), you can use
python's built-in csv module, documented here -
http://docs.python.org/2/library/csv.html, to read the file line by line.
Store the values and substitute the strings into a new list of URLs.


> I need the urls to look like this:
>
> Map with a pin in the centre:
>
> http://maps.googleapis.com/maps/api/staticmap?center=43.65162,-79.40571&zoom=16&size=600x600&markers=color:blue%7Clabel:S%7C43.65162,-79.40571&sensor=false
>
> Image:
>
> http://maps.googleapis.com/maps/api/streetview?location=43.65162,%20-79.40571&size=600x600&sensor=false


I was able to use curl to grab the images you linked. I believe you can use
urllib (or, better, requests - http://docs.python-requests.org/en/latest/)
to get and save the images.

hth.

best,
ken
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From tundra at tundraware.com  Tue May 21 11:27:42 2013
From: tundra at tundraware.com (Tim Daneliuk)
Date: Tue, 21 May 2013 10:27:42 -0500
Subject: Static Maps from Lat Long data in XLS file
In-Reply-To: <d58b4b5f-1b65-48b4-811f-fd81f1c019fe@googlegroups.com>
References: <d58b4b5f-1b65-48b4-811f-fd81f1c019fe@googlegroups.com>
Message-ID: <ccgs6a-1eo.ln1@ozzie.tundraware.com>

On 05/21/2013 08:12 AM, kobewka at gmail.com wrote:
> Hello,
>
> I'm new to Python, but I think it can solve my problem and I am looking for a someone to point me to tutorial or give me some tips here.
>
> I have an xls file that has about 1,000 latitude and longitude points. I want to do one of two things: 1) Save a static maps and street view image from the coordinates, or 2) create an html file with the map and street view image side by side.
>
> I need the urls to look like this:
>
> Map with a pin in the centre:
> http://maps.googleapis.com/maps/api/staticmap?center=43.65162,-79.40571&zoom=16&size=600x600&markers=color:blue%7Clabel:S%7C43.65162,-79.40571&sensor=false
>
> Image:
> http://maps.googleapis.com/maps/api/streetview?location=43.65162,%20-79.40571&size=600x600&sensor=false
>
> I am not sure if option 1 will work because the url doesn't actually lead to an image, but rather Google returns an image when that url is used.
>
> Any tips or pointers are much appreciated!
>


https://pypi.python.org/pypi/xlrd



-- 
-----------------------------------------------------------------------
Tim Daneliuk


From kobewka at gmail.com  Wed May 22 07:21:59 2013
From: kobewka at gmail.com (kobewka at gmail.com)
Date: Wed, 22 May 2013 04:21:59 -0700 (PDT)
Subject: Static Maps from Lat Long data in XLS file
In-Reply-To: <ccgs6a-1eo.ln1@ozzie.tundraware.com>
References: <d58b4b5f-1b65-48b4-811f-fd81f1c019fe@googlegroups.com>
	<ccgs6a-1eo.ln1@ozzie.tundraware.com>
Message-ID: <9dbdf222-8a2f-4edc-b9c9-7c1d7e8f4ddf@googlegroups.com>

On Tuesday, May 21, 2013 11:27:42 AM UTC-4, Tim Daneliuk wrote:
> On 05/21/2013 08:12 AM, @gmail.com wrote:
> 
> > Hello,
> 
> >
> 
> > I'm new to Python, but I think it can solve my problem and I am looking for a someone to point me to tutorial or give me some tips here.
> 
> >
> 
> > I have an xls file that has about 1,000 latitude and longitude points. I want to do one of two things: 1) Save a static maps and street view image from the coordinates, or 2) create an html file with the map and street view image side by side.
> 
> >
> 
> > I need the urls to look like this:
> 
> >
> 
> > Map with a pin in the centre:
> 
> > http://maps.googleapis.com/maps/api/staticmap?center=43.65162,-79.40571&zoom=16&size=600x600&markers=color:blue%7Clabel:S%7C43.65162,-79.40571&sensor=false
> 
> >
> 
> > Image:
> 
> > http://maps.googleapis.com/maps/api/streetview?location=43.65162,%20-79.40571&size=600x600&sensor=false
> 
> >
> 
> > I am not sure if option 1 will work because the url doesn't actually lead to an image, but rather Google returns an image when that url is used.
> 
> >
> 
> > Any tips or pointers are much appreciated!
> 
> >
> 
> 
> 
> 
> 
> https://pypi.python.org/pypi/xlrd
> 
> 
> 
> 
> 
> 
> 
> -- 
> 
> -----------------------------------------------------------------------
> 
> Tim Daneliuk

Thanks Tim.

Scott


From kobewka at gmail.com  Wed May 22 07:21:12 2013
From: kobewka at gmail.com (kobewka at gmail.com)
Date: Wed, 22 May 2013 04:21:12 -0700 (PDT)
Subject: Static Maps from Lat Long data in XLS file
In-Reply-To: <mailman.1924.1369144728.3114.python-list@python.org>
References: <d58b4b5f-1b65-48b4-811f-fd81f1c019fe@googlegroups.com>
	<mailman.1924.1369144728.3114.python-list@python.org>
Message-ID: <a1c3e3d8-4b88-4669-a8a8-e335fbfc5b5c@googlegroups.com>

Thanks Ken. I'll have a closer look at those links. I also found Motionless, which creates a static map HTML file. Combined with what you said, I should be able to get what I need.

https://github.com/ryancox/motionless

Scott



On Tuesday, May 21, 2013 9:58:25 AM UTC-4, Ken Bolton wrote:
> On Tue, May 21, 2013 at 9:12 AM,  <kob... at gmail.com> wrote:
> 
> 
> Hello,
> 
> 
> 
> I'm new to Python, but I think it can solve my problem and I am looking for a someone to point me to tutorial or give me some tips here.
> 
> ?
> Hi! I am a first-time poster to python-list, but I think I can help you.
> 
> 
> ?
> I have an xls file that has about 1,000 latitude and longitude points. I want to do one of two things: 1) Save a static maps and street view image from the coordinates, or 2) create an html file with the map and street view image side by side.
> 
> 
> 
> 
> If you save your xls file as a csv (comma-separated values), you can use python's built-in csv module, documented here - http://docs.python.org/2/library/csv.html, to read the file line by line. Store the values and substitute the strings into a new list of URLs.
> 
> 
> ?
> I need the urls to look like this:
> 
> 
> 
> Map with a pin in the centre:
> 
> http://maps.googleapis.com/maps/api/staticmap?center=43.65162,-79.40571&zoom=16&size=600x600&markers=color:blue%7Clabel:S%7C43.65162,-79.40571&sensor=false
> 
> 
> 
> 
> 
> Image:
> 
> http://maps.googleapis.com/maps/api/streetview?location=43.65162,%20-79.40571&size=600x600&sensor=false
> 
> 
> 
> 
> I was able to use curl to grab the images you linked. I believe you can use urllib (or, better, requests - http://docs.python-requests.org/en/latest/) to get and save the images.
> 
> 
> 
> 
> hth.
> 
> 
> best,
> ken


From harry.percival at gmail.com  Tue May 21 09:41:15 2013
From: harry.percival at gmail.com (Harry Percival)
Date: Tue, 21 May 2013 14:41:15 +0100
Subject: suggestions for "best practices lite" for small site deployment with
	testing
Message-ID: <CACFvh9-dARLBbb9yPANQ2p2ddz+BpKoSv2iGya+XhcTTD1=wqw@mail.gmail.com>

Hi everyone,

We've been having a bit of a discussion of this topic over on the Python-UK
list (http://mail.python.org/pipermail/python-uk/2013-May/thread.html#2949),
and I was a bit shy about mailing out to the big, bad, worldwide Python
list, but I'm forcing myself!

So I'm writing a book, for O'Reilly, on TDD with Python, and I'm looking
for some help and suggestions on my current chapter (well, I'm looking for
help and suggestions in general too!  i need all the help i can get.).

http://www.obeythetestinggoat.com/what-to-say-about-deployment.html

So far I've taken the user through building a basic site, and now I want to
get them to deploy it.  It's very early days, but minimum-viable-product
and all that, deploying early + often is a good habit to get into.

cf the blog post above for a bit of background.  I'm currently leaning away
from talking about the various PaaS offerings, they being too many +
varied, and I have a bit of a conflict of interest since I work at
PythonAnywere.  Instead, I'm currently thinking we'll spin up a small linux
box, put apache on it, and run both the staging and live site from  there.
All good stuff to learn...  Hopefully some of the lessons will be
applicable to PaaSes anyway.

So, some questions:
provisioning = spinning up a server, installing apache, setting up
virtualhost config.  confirm I should encourage people to automate this?
Am leaning towards just using fabric, is bringing in another tool
(chef/puppet/salt) overkill?

deployment = updating the source code, database migration, static files.
What are your favourite ways of doing this?  Shell scripts? Git push
hooks?  I'm thinking fabric, again...

Also: testing -- if the above two steps are automated using fabric, they'll
be *functionally* tested because we'll run the functional test suite
against the staging site.  Any thoughts on whether + how to *unit* test
deployment scripts?

Take a look at the blog post, and let me know what you think?  Bear in
mind, at this stage, I'm looking for "best practices lite" -- at this
stage, it's a tiny website, I can always bring in some more complexity
later on.  The idea is to get people introduced to the idea of deployment,
how you automated, and where testing comes in.  We don't have to talk about
CDNs or zero-downtime or multi-server configuration management yet...

Thanks in advance for any thoughts!
Harry

-- 
------------------------------
Harry J.W. Percival
------------------------------
Twitter: @hjwp
Mobile:  +44 (0) 78877 02511
Skype:         harry.percival
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From jldunn2000 at gmail.com  Tue May 21 11:26:13 2013
From: jldunn2000 at gmail.com (loial)
Date: Tue, 21 May 2013 08:26:13 -0700 (PDT)
Subject: How to raise a socket "104 connection reset by peer error"
Message-ID: <b3a60c4b-9077-4f05-9269-64f5d899a2e7@googlegroups.com>

For testing purposes I want my code to raise a socket "connection reset by peer" error, so that I can test how I handle it, but I am not sure how to raise the error.

Any advice appreciated

  


From bahamutzero8825 at gmail.com  Tue May 21 11:49:31 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Tue, 21 May 2013 10:49:31 -0500
Subject: How to raise a socket "104 connection reset by peer error"
In-Reply-To: <b3a60c4b-9077-4f05-9269-64f5d899a2e7@googlegroups.com>
References: <b3a60c4b-9077-4f05-9269-64f5d899a2e7@googlegroups.com>
Message-ID: <519B978B.2070603@gmail.com>

On 2013.05.21 10:26, loial wrote:
> For testing purposes I want my code to raise a socket "connection reset by peer" error, so that I can test how I handle it, but I am not sure how to raise the error.
Arbitrary exceptions can be raised with the raise keyword. In Python 3.3, that exact error got its own builtin exception:
http://docs.python.org/3.3/tutorial/errors.html#raising-exceptions
http://docs.python.org/3.3/library/exceptions.html#ConnectionResetError

In earlier versions of Python, you will have to raise OSError and set its errno attribute.

-- 
CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1


From mining.facts at gmail.com  Tue May 21 11:26:46 2013
From: mining.facts at gmail.com (Christian)
Date: Tue, 21 May 2013 08:26:46 -0700 (PDT)
Subject: @staticmethods called more than once
Message-ID: <02f0123d-2f9e-4287-b983-cfa1db9db69c@googlegroups.com>

Hi,

i'm somewhat confused working with @staticmethods. My logger and configuration  methods are called n times, but I have only one call.  
n is number of classes which import the loger and configuration class
in the subfolder mymodule. What might be my mistake mistake?

Many thanks
Christian



### __init__.py ###

from  mymodule.MyLogger import MyLogger
from  mymodule.MyConfig import MyConfig


 
##### my_test.py ##########
from mymodule import MyConfig,MyLogger

#Both methods are static
key,logfile,loglevel = MyConfig().get_config('Logging')
log = MyLogger.set_logger(key,logfile,loglevel)
log.critical(time.time())

#Output
2013-05-21 17:20:37,192 - my_test - 17 - CRITICAL - 1369149637.19
2013-05-21 17:20:37,192 - my_test - 17 - CRITICAL - 1369149637.19
2013-05-21 17:20:37,192 - my_test - 17 - CRITICAL - 1369149637.19
2013-05-21 17:20:37,192 - my_test - 17 - CRITICAL - 1369149637.19



From skip at pobox.com  Tue May 21 11:39:03 2013
From: skip at pobox.com (Skip Montanaro)
Date: Tue, 21 May 2013 10:39:03 -0500
Subject: @staticmethods called more than once
In-Reply-To: <02f0123d-2f9e-4287-b983-cfa1db9db69c@googlegroups.com>
References: <02f0123d-2f9e-4287-b983-cfa1db9db69c@googlegroups.com>
Message-ID: <CANc-5UwztuXt6RYU1yQMrBOtMLyA32F2fYf6SF3iAxZ2bjwvAw@mail.gmail.com>

Don't confuse the use of "static" in Python with its use in C/C++.  From a
post on StackOverflow:

A staticmethod is a method that knows nothing about the class or instance
> it was called on. It just gets the arguments that were passed, no implicit
> first argument. It is basically useless in Python -- you can just use a
> module function instead of a staticmethod.


That is, the "@staticmethod" decorator doesn't mean, "call this function
once."

Skip
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From ethan at stoneleaf.us  Tue May 21 12:30:22 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 21 May 2013 09:30:22 -0700
Subject: @staticmethods called more than once
In-Reply-To: <CANc-5UwztuXt6RYU1yQMrBOtMLyA32F2fYf6SF3iAxZ2bjwvAw@mail.gmail.com>
References: <02f0123d-2f9e-4287-b983-cfa1db9db69c@googlegroups.com>
	<CANc-5UwztuXt6RYU1yQMrBOtMLyA32F2fYf6SF3iAxZ2bjwvAw@mail.gmail.com>
Message-ID: <519BA11E.20408@stoneleaf.us>

On 05/21/2013 08:39 AM, Skip Montanaro wrote:
> Don't confuse the use of "static" in Python with its use in C/C++.  From a post on StackOverflow:
>
>     A staticmethod is a method that knows nothing about the class or instance it was called on. It just gets the
>     arguments that were passed, no implicit first argument. It is basically useless in Python -- you can just use a
>     module function instead of a staticmethod.

For there record, staticmethod is useful when you want to make it possible for subclasses to change behavior.

--
~Ethan~


From dihedral88888 at googlemail.com  Tue May 21 21:23:14 2013
From: dihedral88888 at googlemail.com (88888 Dihedral)
Date: Tue, 21 May 2013 18:23:14 -0700 (PDT)
Subject: @staticmethods called more than once
In-Reply-To: <mailman.1928.1369155111.3114.python-list@python.org>
References: <02f0123d-2f9e-4287-b983-cfa1db9db69c@googlegroups.com>
	<CANc-5UwztuXt6RYU1yQMrBOtMLyA32F2fYf6SF3iAxZ2bjwvAw@mail.gmail.com>
	<mailman.1928.1369155111.3114.python-list@python.org>
Message-ID: <83db731c-bc25-40cd-9271-815e11cb9088@googlegroups.com>

Ethan Furman? 2013?5?22????UTC+8??12?30?22????
> On 05/21/2013 08:39 AM, Skip Montanaro wrote:
> 
> > Don't confuse the use of "static" in Python with its use in C/C++.  From a post on StackOverflow:
> 
> >
> 
> >     A staticmethod is a method that knows nothing about the class or instance it was called on. It just gets the
> 
> >     arguments that were passed, no implicit first argument. It is basically useless in Python -- you can just use a
> 
> >     module function instead of a staticmethod.
> 
> 
> 
> For there record, staticmethod is useful when you want to make it possible for subclasses to change behavior.
> 
> 
> 
> --
> 
> ~Ethan~

I prefer objects in classes with slimer figures not heavily weighted
with trivial methods in each instance construction and clone.

 But this is only my personal style of classes in python.


From gordon at panix.com  Tue May 21 12:34:46 2013
From: gordon at panix.com (John Gordon)
Date: Tue, 21 May 2013 16:34:46 +0000 (UTC)
Subject: @staticmethods called more than once
References: <02f0123d-2f9e-4287-b983-cfa1db9db69c@googlegroups.com>
Message-ID: <kng7n6$efc$1@reader1.panix.com>

In <02f0123d-2f9e-4287-b983-cfa1db9db69c at googlegroups.com> Christian <mining.facts at gmail.com> writes:

> Hi,

> i'm somewhat confused working with @staticmethods. My logger and configuration  methods are called n times, but I have only one call.  
> n is number of classes which import the loger and configuration class
> in the subfolder mymodule. What might be my mistake mistake?

> Many thanks
> Christian

> ### __init__.py ###

> from  mymodule.MyLogger import MyLogger
> from  mymodule.MyConfig import MyConfig

> ##### my_test.py ##########
> from mymodule import MyConfig,MyLogger

> #Both methods are static
> key,logfile,loglevel = MyConfig().get_config('Logging')
> log = MyLogger.set_logger(key,logfile,loglevel)
> log.critical(time.time())

> #Output
> 2013-05-21 17:20:37,192 - my_test - 17 - CRITICAL - 1369149637.19
> 2013-05-21 17:20:37,192 - my_test - 17 - CRITICAL - 1369149637.19
> 2013-05-21 17:20:37,192 - my_test - 17 - CRITICAL - 1369149637.19
> 2013-05-21 17:20:37,192 - my_test - 17 - CRITICAL - 1369149637.19

You haven't given us the code for your MyLogger class, so it's difficult
to say exactly what the problem is.

However, I have a guess.  Does MyLogger.set_logger() contain a call to
addHandler()?  Each call to addHandler() adds another handler to your
logger, and when you call log.critical() [or any other log function] you
get one line of output for each handler.

You should only call addHandler() once.

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From gordon at panix.com  Tue May 21 12:48:07 2013
From: gordon at panix.com (John Gordon)
Date: Tue, 21 May 2013 16:48:07 +0000 (UTC)
Subject: @staticmethods called more than once
References: <02f0123d-2f9e-4287-b983-cfa1db9db69c@googlegroups.com>
	<kng7n6$efc$1@reader1.panix.com>
Message-ID: <kng8g7$lcp$1@reader1.panix.com>

In <kng7n6$efc$1 at reader1.panix.com> John Gordon <gordon at panix.com> writes:

> You should only call addHandler() once.

...for each intended logging output destination, of course.  If you want
logging output to appear in a file and on-screen, then you would call
addHandler() once with a file handler and once with a screen handler.

But I think you may be calling addHandler multiple times for the same
file handler, which is causing the duplicate logging output.

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From mining.facts at gmail.com  Tue May 21 13:17:53 2013
From: mining.facts at gmail.com (Christian)
Date: Tue, 21 May 2013 10:17:53 -0700 (PDT)
Subject: @staticmethods called more than once
In-Reply-To: <kng8g7$lcp$1@reader1.panix.com>
References: <02f0123d-2f9e-4287-b983-cfa1db9db69c@googlegroups.com>
	<kng7n6$efc$1@reader1.panix.com> <kng8g7$lcp$1@reader1.panix.com>
Message-ID: <42c56996-231f-476d-add8-375c584b77ee@googlegroups.com>

Am Dienstag, 21. Mai 2013 18:48:07 UTC+2 schrieb John Gordon:
> In <kng7n6$efc$1 at reader1.panix.com> John Gordon <gordon at panix.com> writes:
> 
> 
> 
> > You should only call addHandler() once.
> 
> 
> 
> ...for each intended logging output destination, of course.  If you want
> 
> logging output to appear in a file and on-screen, then you would call
> 
> addHandler() once with a file handler and once with a screen handler.
> 
> 
> 
> But I think you may be calling addHandler multiple times for the same
> 
> file handler, which is causing the duplicate logging output.
> 
> 
> 
> -- 
> 
> John Gordon                   A is for Amy, who fell down the stairs
> 
> gordon at panix.com              B is for Basil, assaulted by bears
> 
>                                 -- Edward Gorey, "The Gashlycrumb Tinies"

Yes you're right.
Many thanks!


From stackoverflowuser95 at gmail.com  Tue May 21 13:27:07 2013
From: stackoverflowuser95 at gmail.com (stackoverflowuser95 at gmail.com)
Date: Tue, 21 May 2013 10:27:07 -0700 (PDT)
Subject: More general way of generating PyODBC queries as a dict?
Message-ID: <0f78102c-2e30-4858-ae62-b8d5cecfc345@googlegroups.com>

Here are my averagely general class methods for creating a dictionary from the result of database queries:

def make_schema_dict(self):
    schema = [i[2] for i in self.cursor.tables()
              if i[2].startswith('tbl_') or i[2].startswith('vw_')]

    self.schema = {table: {'scheme': [row.column_name for row
                                      in self.cursor.columns(table)]}
                   for table in schema}

def last_table_query_as_dict(self, table):
    return {'data': [{col: row.__getattribute__(col) for col in self.schema[table]['scheme']
                      if col != 'RowNum'} for row in self.cursor.fetchall()]}
Unfortunately as you can see, there are many complications.

For example, when multiple tables are queried; some hackish lambdas are required to generate the resulting dictionary.

Can you think of some more general methods?

(and yes I know this is against the PEP; and that this is also on SO)


From stackoverflowuser95 at gmail.com  Wed May 22 05:31:57 2013
From: stackoverflowuser95 at gmail.com (stackoverflowuser95 at gmail.com)
Date: Wed, 22 May 2013 02:31:57 -0700 (PDT)
Subject: More general way of generating PyODBC queries as a dict?
In-Reply-To: <0f78102c-2e30-4858-ae62-b8d5cecfc345@googlegroups.com>
References: <0f78102c-2e30-4858-ae62-b8d5cecfc345@googlegroups.com>
Message-ID: <350aaf43-2259-44cc-9ca3-e86a6823164d@googlegroups.com>

On Wednesday, May 22, 2013 9:33:18 AM UTC+10, Dennis Lee Bieber wrote:
> On Tue, 21 May 2013 10:27:07 -0700 (PDT), stackoverflowuser95 at gmail.com
> 
> declaimed the following in gmane.comp.python.general:
> 
> 
> 
> > 
> 
> > For example, when multiple tables are queried; some hackish lambdas are required to generate the resulting dictionary.
> 
> > 
> 
> > Can you think of some more general methods?
> 
> >
> 
> 	What about using the information from 
> 
> 
> 
> 		cursor.description
> 
> 
> 
> You did state PyODBC, did you not?
> 
> 
> 
> """
> 
> description
> 
> 
> 
> This read-only attribute is a list of 7-item tuples, each containing
> 
> (name, type_code, display_size, internal_size, precision, scale,
> 
> null_ok). pyodbc only provides values for name, type_code,
> 
> internal_size, and null_ok. The other values are set to None.  
> 
> """
> 
> -- 
> 
> 	Wulfraed                 Dennis Lee Bieber         AF6VN
> 
>         wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/

YAY: `[{c[0]: v for (c, v) in zip(row.cursor_description, row)} for row in self.cursor.fetchall()]`


From gvanem at broadpark.no  Tue May 21 15:35:46 2013
From: gvanem at broadpark.no (Gisle Vanem)
Date: Tue, 21 May 2013 21:35:46 +0200
Subject: Modules list-tool
Message-ID: <E26A0E38354D45778EDE4B250DE2B7FB@dev.null>

Are anyone aware of a tool that can show me at run-time
which modules (pyd/dll) are loaded into a Python program 
at a specific time (or over time)?

To clarify, e.g. when running a sample from PyQt4
(examples\tutorials\addressbook\part1.pyw) and using Process Explorer [1],
I can launch WinDbg from it and get this list of modules:
....

ModLoad: 1d000000 1d00a000   G:\ProgramFiler\Python27\python.EXE
ModLoad: 7c900000 7c9b1000   F:\WINDOWS\system32\ntdll.dll
ModLoad: 7c800000 7c8f7000   F:\WINDOWS\system32\kernel32.dll
ModLoad: 1e000000 1e261000   f:\windows\system32\python27.dll
ModLoad: 7e410000 7e4a1000   F:\WINDOWS\system32\USER32.dll
ModLoad: 77f10000 77f59000   F:\WINDOWS\system32\GDI32.dll
ModLoad: 77dc0000 77e6a000   F:\WINDOWS\system32\ADVAPI32.dll
ModLoad: 77e70000 77f03000   F:\WINDOWS\system32\RPCRT4.dll
ModLoad: 77fe0000 77ff1000   F:\WINDOWS\system32\Secur32.dll
ModLoad: 7c9c0000 7d1d8000   F:\WINDOWS\system32\SHELL32.dll
ModLoad: 77c00000 77c58000   F:\WINDOWS\system32\msvcrt.dll
ModLoad: 77f60000 77fd6000   F:\WINDOWS\system32\SHLWAPI.dll
ModLoad: 78520000 785c3000   f:\windows\WinSxS\x86_Microsoft.VC90.CRT_1fc8b3b9a1e18e3b_9.0.30729.6161_x-ww_31a54e43\MSVCR90.dll
ModLoad: 76370000 7638d000   f:\windows\system32\IMM32.DLL
ModLoad: 62f20000 62f29000   f:\windows\system32\LPK.DLL
ModLoad: 75420000 7548b000   f:\windows\system32\USP10.dll
ModLoad: 773c0000 774c3000 
f:\windows\WinSxS\x86_Microsoft.Windows.Common-Controls_6595b64144ccf1df_6.0.2600.6028_x-ww_61e65202\comctl32.dll
ModLoad: 5d5d0000 5d66a000   F:\WINDOWS\system32\comctl32.dll
ModLoad: 78aa0000 78b5f000   f:\windows\system32\MSVCR100.dll
ModLoad: 00d90000 00f29000   g:\ProgramFiler\Python27\lib\site-packages\PyQt4\QtCore.pyd
ModLoad: 67000000 67260000   g:\ProgramFiler\Python27\lib\site-packages\PyQt4\QtCore4.dll
ModLoad: 774d0000 7760e000   F:\WINDOWS\system32\ole32.dll
ModLoad: 71aa0000 71ab7000   f:\windows\system32\WS2_32.dll
ModLoad: 71a90000 71a98000   f:\windows\system32\WS2HELP.dll
ModLoad: 78480000 7850e000   f:\windows\WinSxS\x86_Microsoft.VC90.CRT_1fc8b3b9a1e18e3b_9.0.30729.6161_x-ww_31a54e43\MSVCP90.dll
ModLoad: 00a60000 00a73000   g:\ProgramFiler\Python27\lib\site-packages\sip.pyd
ModLoad: 011f0000 0177f000   g:\ProgramFiler\Python27\lib\site-packages\PyQt4\QtGui.pyd
ModLoad: 65000000 657c4000   g:\ProgramFiler\Python27\lib\site-packages\PyQt4\QtGui4.dll
...

-------------

My example may be mooth since part1.pyw above (when I enter
the debugger) is just waiting for events. The stack of pythonw.exe 
as shown in Process Explorer:
...
ntdll.dll!ZwWaitForMultipleObjects+0xc
kernel32.dll!WaitForMultipleObjectsEx+0x12c
USER32.dll!RealMsgWaitForMultipleObjectsEx+0x13e
QtCore4.dll!QEventDispatcherWin32::processEvents+0x3c3
ntdll.dll!RtlAcquirePebLock+0x28

Is there a tool that can do something similar? (written in Python maybe?). 
But a bit simpler to use than my current method. Just launch it from the 
command-line; something like "pyXX part1.pyw <more args>"

[1] http://technet.microsoft.com/en-gb/sysinternals/bb896653

--gv 



From drsalists at gmail.com  Thu May 23 00:39:52 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Wed, 22 May 2013 21:39:52 -0700
Subject: Modules list-tool
In-Reply-To: <E26A0E38354D45778EDE4B250DE2B7FB@dev.null>
References: <E26A0E38354D45778EDE4B250DE2B7FB@dev.null>
Message-ID: <CAGGBd_qQzx88Roy7aUMCGOw_h11GapgLK+C677tqV0pd9G7wMg@mail.gmail.com>

On Tue, May 21, 2013 at 12:35 PM, Gisle Vanem <gvanem at broadpark.no> wrote:

> Are anyone aware of a tool that can show me at run-time
> which modules (pyd/dll) are loaded into a Python program at a specific
> time (or over time)?
>
> To clarify, e.g. when running a sample from PyQt4
> (examples\tutorials\**addressbook\part1.pyw) and using Process Explorer
> [1],
> I can launch WinDbg from it and get this list of modules:
> ....
>
> ModLoad: 1d000000 1d00a000   G:\ProgramFiler\Python27\**python.EXE
> ModLoad: 7c900000 7c9b1000   F:\WINDOWS\system32\ntdll.dll
> ModLoad: 7c800000 7c8f7000   F:\WINDOWS\system32\kernel32.**dll
> ModLoad: 1e000000 1e261000   f:\windows\system32\python27.**dll
> ModLoad: 7e410000 7e4a1000   F:\WINDOWS\system32\USER32.dll
> ModLoad: 77f10000 77f59000   F:\WINDOWS\system32\GDI32.dll
> ModLoad: 77dc0000 77e6a000   F:\WINDOWS\system32\ADVAPI32.**dll
> ModLoad: 77e70000 77f03000   F:\WINDOWS\system32\RPCRT4.dll
> ModLoad: 77fe0000 77ff1000   F:\WINDOWS\system32\Secur32.**dll
> ModLoad: 7c9c0000 7d1d8000   F:\WINDOWS\system32\SHELL32.**dll
> ModLoad: 77c00000 77c58000   F:\WINDOWS\system32\msvcrt.dll
> ModLoad: 77f60000 77fd6000   F:\WINDOWS\system32\SHLWAPI.**dll
> ModLoad: 78520000 785c3000   f:\windows\WinSxS\x86_**Microsoft.VC90.CRT_**
> 1fc8b3b9a1e18e3b_9.0.30729.**6161_x-ww_31a54e43\MSVCR90.dll
> ModLoad: 76370000 7638d000   f:\windows\system32\IMM32.DLL
> ModLoad: 62f20000 62f29000   f:\windows\system32\LPK.DLL
> ModLoad: 75420000 7548b000   f:\windows\system32\USP10.dll
> ModLoad: 773c0000 774c3000 f:\windows\WinSxS\x86_**
> Microsoft.Windows.Common-**Controls_6595b64144ccf1df_6.0.2600.6028_x-**
> ww_61e65202\comctl32.dll
> ModLoad: 5d5d0000 5d66a000   F:\WINDOWS\system32\comctl32.**dll
> ModLoad: 78aa0000 78b5f000   f:\windows\system32\MSVCR100.**dll
> ModLoad: 00d90000 00f29000   g:\ProgramFiler\Python27\lib\**
> site-packages\PyQt4\QtCore.pyd
> ModLoad: 67000000 67260000   g:\ProgramFiler\Python27\lib\**
> site-packages\PyQt4\QtCore4.**dll
> ModLoad: 774d0000 7760e000   F:\WINDOWS\system32\ole32.dll
> ModLoad: 71aa0000 71ab7000   f:\windows\system32\WS2_32.dll
> ModLoad: 71a90000 71a98000   f:\windows\system32\WS2HELP.**dll
> ModLoad: 78480000 7850e000   f:\windows\WinSxS\x86_**Microsoft.VC90.CRT_**
> 1fc8b3b9a1e18e3b_9.0.30729.**6161_x-ww_31a54e43\MSVCP90.dll
> ModLoad: 00a60000 00a73000   g:\ProgramFiler\Python27\lib\**
> site-packages\sip.pyd
> ModLoad: 011f0000 0177f000   g:\ProgramFiler\Python27\lib\**
> site-packages\PyQt4\QtGui.pyd
> ModLoad: 65000000 657c4000   g:\ProgramFiler\Python27\lib\**
> site-packages\PyQt4\QtGui4.dll
> ...
>
> -------------
>
> My example may be mooth since part1.pyw above (when I enter
> the debugger) is just waiting for events. The stack of pythonw.exe as
> shown in Process Explorer:
> ...
> ntdll.dll!**ZwWaitForMultipleObjects+0xc
> kernel32.dll!**WaitForMultipleObjectsEx+0x12c
> USER32.dll!**RealMsgWaitForMultipleObjectsE**x+0x13e
> QtCore4.dll!**QEventDispatcherWin32::**processEvents+0x3c3
> ntdll.dll!RtlAcquirePebLock+**0x28
>
> Is there a tool that can do something similar? (written in Python maybe?).
> But a bit simpler to use than my current method. Just launch it from the
> command-line; something like "pyXX part1.pyw <more args>"
>
> [1] http://technet.microsoft.com/**en-gb/sysinternals/bb896653<http://technet.microsoft.com/en-gb/sysinternals/bb896653>
>
> --gv
> --
> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>

Python -v reports on modules.
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From carlosnepomuceno at outlook.com  Thu May 23 01:19:31 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 08:19:31 +0300
Subject: Modules list-tool
In-Reply-To: <CAGGBd_qQzx88Roy7aUMCGOw_h11GapgLK+C677tqV0pd9G7wMg@mail.gmail.com>
References: <E26A0E38354D45778EDE4B250DE2B7FB@dev.null>,
	<CAGGBd_qQzx88Roy7aUMCGOw_h11GapgLK+C677tqV0pd9G7wMg@mail.gmail.com>
Message-ID: <BLU176-W32B8EAAD29228E97D130FFD7AA0@phx.gbl>

Have you tried Inspect Shell[1]?

All you have to do to monitor your script is include "import inspect_shell" in the 1st line of you source code and then run:

"python inspect_shell.py"

When you get the prompt you can enter the following to show the list of modules:

localhost:1234> '\n'.join(['{}={}'.format(k,v) for k,v in sys.modules.items()])


[1] https://github.com/amoffat/Inspect-Shell


________________________________
> Date: Wed, 22 May 2013 21:39:52 -0700 
> Subject: Re: Modules list-tool 
> From: drsalists at gmail.com 
> To: gvanem at broadpark.no 
> CC: python-list at python.org 
>  
> On Tue, May 21, 2013 at 12:35 PM, Gisle Vanem  
> <gvanem at broadpark.no<mailto:gvanem at broadpark.no>> wrote: 
> Are anyone aware of a tool that can show me at run-time 
> which modules (pyd/dll) are loaded into a Python program at a specific  
> time (or over time)? 
>  
> To clarify, e.g. when running a sample from PyQt4 
> (examples\tutorials\addressbook\part1.pyw) and using Process Explorer [1], 
> I can launch WinDbg from it and get this list of modules: 
> .... 
>  
> ModLoad: 1d000000 1d00a000   G:\ProgramFiler\Python27\python.EXE 
> ModLoad: 7c900000 7c9b1000   F:\WINDOWS\system32\ntdll.dll 
> ModLoad: 7c800000 7c8f7000   F:\WINDOWS\system32\kernel32.dll 
> ModLoad: 1e000000 1e261000   f:\windows\system32\python27.dll 
> ModLoad: 7e410000 7e4a1000   F:\WINDOWS\system32\USER32.dll 
> ModLoad: 77f10000 77f59000   F:\WINDOWS\system32\GDI32.dll 
> ModLoad: 77dc0000 77e6a000   F:\WINDOWS\system32\ADVAPI32.dll 
> ModLoad: 77e70000 77f03000   F:\WINDOWS\system32\RPCRT4.dll 
> ModLoad: 77fe0000 77ff1000   F:\WINDOWS\system32\Secur32.dll 
> ModLoad: 7c9c0000 7d1d8000   F:\WINDOWS\system32\SHELL32.dll 
> ModLoad: 77c00000 77c58000   F:\WINDOWS\system32\msvcrt.dll 
> ModLoad: 77f60000 77fd6000   F:\WINDOWS\system32\SHLWAPI.dll 
> ModLoad: 78520000 785c3000    
> f:\windows\WinSxS\x86_Microsoft.VC90.CRT_1fc8b3b9a1e18e3b_9.0.30729.6161_x-ww_31a54e43\MSVCR90.dll 
> ModLoad: 76370000 7638d000   f:\windows\system32\IMM32.DLL 
> ModLoad: 62f20000 62f29000   f:\windows\system32\LPK.DLL 
> ModLoad: 75420000 7548b000   f:\windows\system32\USP10.dll 
> ModLoad: 773c0000 774c3000  
> f:\windows\WinSxS\x86_Microsoft.Windows.Common-Controls_6595b64144ccf1df_6.0.2600.6028_x-ww_61e65202\comctl32.dll 
> ModLoad: 5d5d0000 5d66a000   F:\WINDOWS\system32\comctl32.dll 
> ModLoad: 78aa0000 78b5f000   f:\windows\system32\MSVCR100.dll 
> ModLoad: 00d90000 00f29000    
> g:\ProgramFiler\Python27\lib\site-packages\PyQt4\QtCore.pyd 
> ModLoad: 67000000 67260000    
> g:\ProgramFiler\Python27\lib\site-packages\PyQt4\QtCore4.dll 
> ModLoad: 774d0000 7760e000   F:\WINDOWS\system32\ole32.dll 
> ModLoad: 71aa0000 71ab7000   f:\windows\system32\WS2_32.dll 
> ModLoad: 71a90000 71a98000   f:\windows\system32\WS2HELP.dll 
> ModLoad: 78480000 7850e000    
> f:\windows\WinSxS\x86_Microsoft.VC90.CRT_1fc8b3b9a1e18e3b_9.0.30729.6161_x-ww_31a54e43\MSVCP90.dll 
> ModLoad: 00a60000 00a73000    
> g:\ProgramFiler\Python27\lib\site-packages\sip.pyd 
> ModLoad: 011f0000 0177f000    
> g:\ProgramFiler\Python27\lib\site-packages\PyQt4\QtGui.pyd 
> ModLoad: 65000000 657c4000    
> g:\ProgramFiler\Python27\lib\site-packages\PyQt4\QtGui4.dll 
> ... 
>  
> ------------- 
>  
> My example may be mooth since part1.pyw above (when I enter 
> the debugger) is just waiting for events. The stack of pythonw.exe as  
> shown in Process Explorer: 
> ... 
> ntdll.dll!ZwWaitForMultipleObjects+0xc 
> kernel32.dll!WaitForMultipleObjectsEx+0x12c 
> USER32.dll!RealMsgWaitForMultipleObjectsEx+0x13e 
> QtCore4.dll!QEventDispatcherWin32::processEvents+0x3c3 
> ntdll.dll!RtlAcquirePebLock+0x28 
>  
> Is there a tool that can do something similar? (written in Python  
> maybe?). But a bit simpler to use than my current method. Just launch  
> it from the command-line; something like "pyXX part1.pyw <more args>" 
>  
> [1] http://technet.microsoft.com/en-gb/sysinternals/bb896653 
>  
> --gv 
> --  
> http://mail.python.org/mailman/listinfo/python-list 
>  
> Python -v reports on modules. 
>  
> -- http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From info at DatabasePrograms.Biz  Tue May 21 21:15:27 2013
From: info at DatabasePrograms.Biz (info at DatabasePrograms.Biz)
Date: Wed, 22 May 2013 01:15:27 +0000
Subject: A computer programmer, web developer and network admin resume 
Message-ID: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>

A computer programmer, web developer and network administrator resume.

For a resume in HTML or .Doc format click on:
www.DatabasePrograms.Biz<http://www.databaseprograms.biz/>

If you would like this in text format instead, please let me know.


Daniel Rapaport

1-949-307-2485
info at DatabasePrograms.Biz<mailto:info at DatabasePrograms.Biz>







To unsubscribe click on: info at DatabasePrograms.Biz?Subject=unsubscribe<mailto:info at DatabasePrograms.Biz?Subject=unsubscribe>

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From denismfmcmahon at gmail.com  Tue May 21 21:42:39 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Wed, 22 May 2013 01:42:39 +0000 (UTC)
Subject: A computer programmer, web developer and network admin resume
References: <mailman.1943.1369185587.3114.python-list@python.org>
Message-ID: <knh7qf$bue$3@dont-email.me>

On Wed, 22 May 2013 01:15:27 +0000, info at DatabasePrograms.Biz wrote:

> If you would like this in text format instead, please let me know.

What if we don't want it at all?

-- 
Denis McMahon, denismfmcmahon at gmail.com


From python.list at tim.thechases.com  Tue May 21 22:32:06 2013
From: python.list at tim.thechases.com (Tim Chase)
Date: Tue, 21 May 2013 21:32:06 -0500
Subject: A computer programmer, web developer and network admin resume
In-Reply-To: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>
References: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>
Message-ID: <20130521213206.126ce7e0@bigbox.christie.dr>

On 2013-05-22 01:15, info at DatabasePrograms.Biz wrote:
> A computer programmer, web developer and network administrator

...walk into a bar...

So what's the punchline?

-tkc




From rosuav at gmail.com  Wed May 22 02:39:31 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 22 May 2013 16:39:31 +1000
Subject: A computer programmer, web developer and network admin resume
In-Reply-To: <20130521213206.126ce7e0@bigbox.christie.dr>
References: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>
	<20130521213206.126ce7e0@bigbox.christie.dr>
Message-ID: <CAPTjJmq3LkmS514VdSEtkRV3=UuzDmXMeX0hQvCctGKbwaEaSg@mail.gmail.com>

On Wed, May 22, 2013 at 12:32 PM, Tim Chase
<python.list at tim.thechases.com> wrote:
> On 2013-05-22 01:15, info at DatabasePrograms.Biz wrote:
>> A computer programmer, web developer and network administrator
>
> ...walk into a bar...
>
> So what's the punchline?

;steps up to the mike

So yeah, as I was saying, a programmer, a web dev, and a BOFH walk
into a bar. The other two buy the BOFH a drink, because they're not
stupid, and anyway, so this luser walks up to them with a resume in
his hand.

"....," says the luser.

"So what's the punchline?" says the computer programmer.

The stand-up comic steps up to the mike, and he says, "So yeah, as I
was saying, a programmer, a web dev, and a BOFH walk into a stable
time loop..."

ChrisA


From python.list at tim.thechases.com  Wed May 22 09:03:37 2013
From: python.list at tim.thechases.com (Tim Chase)
Date: Wed, 22 May 2013 08:03:37 -0500
Subject: A computer programmer, web developer and network admin resume
In-Reply-To: <CAPTjJmq3LkmS514VdSEtkRV3=UuzDmXMeX0hQvCctGKbwaEaSg@mail.gmail.com>
References: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>
	<20130521213206.126ce7e0@bigbox.christie.dr>
	<CAPTjJmq3LkmS514VdSEtkRV3=UuzDmXMeX0hQvCctGKbwaEaSg@mail.gmail.com>
Message-ID: <20130522080337.5c431bb3@bigbox.christie.dr>

On 2013-05-22 16:39, Chris Angelico wrote:
> On Wed, May 22, 2013 at 12:32 PM, Tim Chase
> <python.list at tim.thechases.com> wrote:
> > On 2013-05-22 01:15, info at DatabasePrograms.Biz wrote:
> >> A computer programmer, web developer and network administrator
> >
> > ...walk into a bar...
> >
> > So what's the punchline?
> 
> ;steps up to the mike
> 
> So yeah, as I was saying, a programmer, a web dev, and a BOFH walk
> into a bar. The other two buy the BOFH a drink, because they're not
> stupid, and anyway, so this luser walks up to them with a resume in
> his hand.
> 
> "....," says the luser.
> 
> "So what's the punchline?" says the computer programmer.
> 
> The stand-up comic steps up to the mike, and he says, "So yeah, as I
> was saying, a programmer, a web dev, and a BOFH walk into a stable
> time loop..."

So a pirate programmer walks into a bar with a bird on his shoulder.
The bird repeatedly squawks "pieces of nine! pieces of nine!".  The
bartender looks at him and asks "what's up with the bird?" to which
the pirate says "Arrr, he's got a parroty error."  The bartender
replies, "Ah, I thought he was a bit off."

-tkc





From harry.percival at gmail.com  Wed May 22 09:10:17 2013
From: harry.percival at gmail.com (Harry Percival)
Date: Wed, 22 May 2013 14:10:17 +0100
Subject: A computer programmer, web developer and network admin resume
In-Reply-To: <20130522080337.5c431bb3@bigbox.christie.dr>
References: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>
	<20130521213206.126ce7e0@bigbox.christie.dr>
	<CAPTjJmq3LkmS514VdSEtkRV3=UuzDmXMeX0hQvCctGKbwaEaSg@mail.gmail.com>
	<20130522080337.5c431bb3@bigbox.christie.dr>
Message-ID: <CACFvh991C2x_oAVCm_yHV0QjKDteag2L1TVkuEW=HPNsQYPx5w@mail.gmail.com>

oh wow.  great one, thanks for that tim :)))))


On 22 May 2013 14:03, Tim Chase <python.list at tim.thechases.com> wrote:

> On 2013-05-22 16:39, Chris Angelico wrote:
> > On Wed, May 22, 2013 at 12:32 PM, Tim Chase
> > <python.list at tim.thechases.com> wrote:
> > > On 2013-05-22 01:15, info at DatabasePrograms.Biz wrote:
> > >> A computer programmer, web developer and network administrator
> > >
> > > ...walk into a bar...
> > >
> > > So what's the punchline?
> >
> > ;steps up to the mike
> >
> > So yeah, as I was saying, a programmer, a web dev, and a BOFH walk
> > into a bar. The other two buy the BOFH a drink, because they're not
> > stupid, and anyway, so this luser walks up to them with a resume in
> > his hand.
> >
> > "....," says the luser.
> >
> > "So what's the punchline?" says the computer programmer.
> >
> > The stand-up comic steps up to the mike, and he says, "So yeah, as I
> > was saying, a programmer, a web dev, and a BOFH walk into a stable
> > time loop..."
>
> So a pirate programmer walks into a bar with a bird on his shoulder.
> The bird repeatedly squawks "pieces of nine! pieces of nine!".  The
> bartender looks at him and asks "what's up with the bird?" to which
> the pirate says "Arrr, he's got a parroty error."  The bartender
> replies, "Ah, I thought he was a bit off."
>
> -tkc
>
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>



-- 
------------------------------
Harry J.W. Percival
------------------------------
Twitter: @hjwp
Mobile:  +44 (0) 78877 02511
Skype:         harry.percival
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From greg.ewing at canterbury.ac.nz  Wed May 22 19:25:55 2013
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Thu, 23 May 2013 11:25:55 +1200
Subject: A computer programmer, web developer and network admin resume
In-Reply-To: <mailman.1964.1369227699.3114.python-list@python.org>
References: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>	<20130521213206.126ce7e0@bigbox.christie.dr>	<CAPTjJmq3LkmS514VdSEtkRV3=UuzDmXMeX0hQvCctGKbwaEaSg@mail.gmail.com>
	<mailman.1964.1369227699.3114.python-list@python.org>
Message-ID: <b052g3FlqugU1@mid.individual.net>

Tim Chase wrote:
> So a pirate programmer walks into a bar with a bird on his shoulder.
> The bird repeatedly squawks "pieces of nine! pieces of nine!".  The
> bartender looks at him and asks "what's up with the bird?" to which
> the pirate says "Arrr, he's got a parroty error."

No, he's just using half-open ranges.

-- 
Greg


From ken at bscientific.net  Wed May 22 21:31:13 2013
From: ken at bscientific.net (Ken Bolton)
Date: Wed, 22 May 2013 21:31:13 -0400
Subject: A computer programmer, web developer and network admin resume
In-Reply-To: <b052g3FlqugU1@mid.individual.net>
References: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>
	<20130521213206.126ce7e0@bigbox.christie.dr>
	<CAPTjJmq3LkmS514VdSEtkRV3=UuzDmXMeX0hQvCctGKbwaEaSg@mail.gmail.com>
	<mailman.1964.1369227699.3114.python-list@python.org>
	<b052g3FlqugU1@mid.individual.net>
Message-ID: <CAN7ek0N_hEXYWUdjXOSZighNsaxGWXW=A-zMO=sR_KTUdMb4WA@mail.gmail.com>

On Wed, May 22, 2013 at 7:25 PM, Gregory Ewing
<greg.ewing at canterbury.ac.nz>wrote:

> Tim Chase wrote:
>
>> So a pirate programmer walks into a bar with a bird on his shoulder.
>> The bird repeatedly squawks "pieces of nine! pieces of nine!".  The
>> bartender looks at him and asks "what's up with the bird?" to which
>> the pirate says "Arrr, he's got a parroty error."
>>
>
> No, he's just using half-open ranges.


That is the punchline for the one about the cowboy programmer.
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From neilc at norwich.edu  Thu May 23 08:28:43 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 23 May 2013 12:28:43 GMT
Subject: A computer programmer, web developer and network admin resume
References: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>
	<mailman.1945.1369189815.3114.python-list@python.org>
Message-ID: <b06gbqFam3U1@mid.individual.net>

On 2013-05-22, Tim Chase <python.list at tim.thechases.com> wrote:
> On 2013-05-22 01:15, info at DatabasePrograms.Biz wrote:
>> A computer programmer, web developer and network administrator
>
> ...walk into a bar...
>
> So what's the punchline?

"Ow." Get it? "Ow."

-- 
Neil Cerutti


From rosuav at gmail.com  Thu May 23 08:35:05 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 22:35:05 +1000
Subject: A computer programmer, web developer and network admin resume
In-Reply-To: <b06gbqFam3U1@mid.individual.net>
References: <aeb17e071a3347d39e11954b319fd7ee@Ex13DAG10-N2.dataoncloud.net>
	<mailman.1945.1369189815.3114.python-list@python.org>
	<b06gbqFam3U1@mid.individual.net>
Message-ID: <CAPTjJmokr0JO+wRy2TPaYm8J=_+H6QxG6Li-wj=iSTK4ZSsCqg@mail.gmail.com>

On Thu, May 23, 2013 at 10:28 PM, Neil Cerutti <neilc at norwich.edu> wrote:
> On 2013-05-22, Tim Chase <python.list at tim.thechases.com> wrote:
>> On 2013-05-22 01:15, info at DatabasePrograms.Biz wrote:
>>> A computer programmer, web developer and network administrator
>>
>> ...walk into a bar...
>>
>> So what's the punchline?
>
> "Ow." Get it? "Ow."

Better, better, but Waaaah!

Wait. This isn't getting-hit-on-the-head-with-a-bad-joke lessons?

ChrisA


From carlosnepomuceno at outlook.com  Tue May 21 22:26:11 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 22 May 2013 05:26:11 +0300
Subject: Myth Busters: % "this old style of formatting will eventually be
	removed from the language"
Message-ID: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>

I was looking for something else and just found what I think is the place where I was first exposed to the myth[1]:

"Since?str.format()?is quite new, a lot of Python code still uses the?%?operator. However, because this old style of formatting will eventually be removed from the language,?str.format()?should generally be used."

Is this tutorial outdated or this still an issue?

[1] http://docs.python.org/2/tutorial/inputoutput.html#old-string-formatting 		 	   		  

From ethan at stoneleaf.us  Tue May 21 22:37:32 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 21 May 2013 19:37:32 -0700
Subject: Myth Busters: % "this old style of formatting will eventually
	be removed from the language"
In-Reply-To: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>
References: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>
Message-ID: <519C2F6C.3050901@stoneleaf.us>

On 05/21/2013 07:26 PM, Carlos Nepomuceno wrote:
> I was looking for something else and just found what I think is the place where I was first exposed to the myth[1]:
>
> "Since str.format() is quite new, a lot of Python code still uses the % operator. However, because this old style of formatting will eventually be removed from the language, str.format() should generally be used."
>
> Is this tutorial outdated or this still an issue?

It was exuberant wishful thinking.  ;)

While .format() does have its uses, % is in wide-spread use even among the core-devs.  It's not going away any time soon.

--
~Ethan~


From ned at nedbatchelder.com  Tue May 21 23:26:58 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Tue, 21 May 2013 23:26:58 -0400
Subject: Myth Busters: % "this old style of formatting will eventually
	be removed from the language"
In-Reply-To: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>
References: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>
Message-ID: <519C3B02.1020706@nedbatchelder.com>

On 5/21/2013 10:26 PM, Carlos Nepomuceno wrote:
> I was looking for something else and just found what I think is the place where I was first exposed to the myth[1]:
>
> "Since str.format() is quite new, a lot of Python code still uses the % operator. However, because this old style of formatting will eventually be removed from the language, str.format() should generally be used."
>
> Is this tutorial outdated or this still an issue?
>
> [1] http://docs.python.org/2/tutorial/inputoutput.html#old-string-formatting 		 	   		

That tutorial is out of date.  %-formatting isn't being removed.

--Ned.


From carlosnepomuceno at outlook.com  Wed May 22 01:59:54 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 22 May 2013 08:59:54 +0300
Subject: Myth Busters: % "this old style of formatting will eventually
	be removed from the language"
In-Reply-To: <519C3B02.1020706@nedbatchelder.com>
References: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>,
	<519C3B02.1020706@nedbatchelder.com>
Message-ID: <BLU176-W338612B1BA5526B8866F12D7A90@phx.gbl>

Ok. Thanks!

bugs.python.org/issue18031

----------------------------------------
> Date: Tue, 21 May 2013 23:26:58 -0400
> From: ned at nedbatchelder.com
> To: carlosnepomuceno at outlook.com
> CC: python-list at python.org
> Subject: Re: Myth Busters: % "this old style of formatting will eventually be removed from the language"
>
> On 5/21/2013 10:26 PM, Carlos Nepomuceno wrote:
>> I was looking for something else and just found what I think is the place where I was first exposed to the myth[1]:
>>
>> "Since str.format() is quite new, a lot of Python code still uses the % operator. However, because this old style of formatting will eventually be removed from the language, str.format() should generally be used."
>>
>> Is this tutorial outdated or this still an issue?
>>
>> [1] http://docs.python.org/2/tutorial/inputoutput.html#old-string-formatting
>
> That tutorial is out of date. %-formatting isn't being removed.
>
> --Ned. 		 	   		  

From skip at pobox.com  Wed May 22 06:35:42 2013
From: skip at pobox.com (Skip Montanaro)
Date: Wed, 22 May 2013 05:35:42 -0500
Subject: Myth Busters: % "this old style of formatting will eventually be
	removed from the language"
In-Reply-To: <519C3B02.1020706@nedbatchelder.com>
References: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>
	<519C3B02.1020706@nedbatchelder.com>
Message-ID: <CANc-5UwyRhvie+EBH3wMca4DX0j8aau+5iXvZmx5gCSsDOr5vw@mail.gmail.com>

>> Is this tutorial outdated or this still an issue?
>>
>> [1]
>> http://docs.python.org/2/tutorial/inputoutput.html#old-string-formatting
>
>
> That tutorial is out of date.  %-formatting isn't being removed.

OTOH, PEP 3101 also mentions deprecation, at the very end: "... both
systems can co-exist until it comes time to deprecate the older
system."

I have been operating under the assumption since the days of that PEP
that %-style formatting would eventually disappear, dreading the day
when I'd have to learn the str.format language.  I apologize for
(inadvertently) spreading FUD.

It does seem like the documentation should be updated in a few places.
 If the decision has been made to not remove the older system, it
might be worthwhile to mention that somewhere.  Clearly the tutorial
and PEP 3101 should be updated.

Skip


From pruebauno at latinmail.com  Wed May 22 15:49:51 2013
From: pruebauno at latinmail.com (nn)
Date: Wed, 22 May 2013 12:49:51 -0700 (PDT)
Subject: Myth Busters: % "this old style of formatting will eventually be
	removed from the language"
References: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>
	<519C3B02.1020706@nedbatchelder.com>
	<mailman.1957.1369218950.3114.python-list@python.org>
Message-ID: <252d4afd-9d8c-4ae3-83cc-6e9c830b1706@r3g2000yqe.googlegroups.com>

On May 22, 6:35?am, Skip Montanaro <s... at pobox.com> wrote:
> >> Is this tutorial outdated or this still an issue?
>
> >> [1]
> >>http://docs.python.org/2/tutorial/inputoutput.html#old-string-formatting
>
> > That tutorial is out of date. ?%-formatting isn't being removed.
>
> OTOH, PEP 3101 also mentions deprecation, at the very end: "... both
> systems can co-exist until it comes time to deprecate the older
> system."
>
> I have been operating under the assumption since the days of that PEP
> that %-style formatting would eventually disappear, dreading the day
> when I'd have to learn the str.format language. ?I apologize for
> (inadvertently) spreading FUD.
>
> It does seem like the documentation should be updated in a few places.
> ?If the decision has been made to not remove the older system, it
> might be worthwhile to mention that somewhere. ?Clearly the tutorial
> and PEP 3101 should be updated.
>
> Skip

I was of the impression that deprecating % was still planned for Py4k,
whenever that is. I personally believe that eliminating % formatting
would reduce bugs and generally make code clearer, but I realize that
breaking backward compatibility has a high price.



From denismfmcmahon at gmail.com  Wed May 22 10:24:03 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Wed, 22 May 2013 14:24:03 +0000 (UTC)
Subject: Myth Busters: % "this old style of formatting will eventually
	be removed from the language"
References: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>
	<mailman.1949.1369193229.3114.python-list@python.org>
Message-ID: <knike3$v6m$2@dont-email.me>

On Tue, 21 May 2013 23:26:58 -0400, Ned Batchelder wrote:

> On 5/21/2013 10:26 PM, Carlos Nepomuceno wrote:

>> "Since str.format() is quite new, a lot of Python code still uses the %
>> operator. However, because this old style of formatting will eventually
>> be removed from the language, str.format() should generally be used."

>> Is this tutorial outdated or this still an issue?

> That tutorial is out of date.  %-formatting isn't being removed.

Indeed, removing %-formatting could break a substantial amount of live 
code, with potentially significant maintenance effort in the user 
community simply to make existing code work with the new interpreter. The 
effect of this on corporations using python code translates into 
"business risk", and the next step is "we can avoid the business risk by 
migrating our python scripts to some other language."

For the designers and maintainers of any language to arbitrarily[1] (in 
the eyes of the user base) remove a widely used feature that would have a 
major effect on the user base could kill off a language, simply because 
many users will not want to take the risk of it happening again, even if 
they can easily automate the upgrade from removed obsolete language 
feature to new shiny language feature.

[1] Some portion of the user base will always consider any such change 
that causes them headaches and additional effort as having been 
arbitrary, no matter how well the language designers and maintainers 
explain the need to break the old scripts.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From tjreedy at udel.edu  Wed May 22 15:40:22 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Wed, 22 May 2013 15:40:22 -0400
Subject: Myth Busters: % "this old style of formatting will eventually
	be removed from the language"
In-Reply-To: <knike3$v6m$2@dont-email.me>
References: <BLU176-W25D89313A094EE7C675E0DD7A90@phx.gbl>
	<mailman.1949.1369193229.3114.python-list@python.org>
	<knike3$v6m$2@dont-email.me>
Message-ID: <knj6us$e0i$1@ger.gmane.org>

On 5/22/2013 10:24 AM, Denis McMahon wrote:

> Indeed, removing %-formatting could break a substantial amount of live
> code, with potentially significant maintenance effort in the user

While I would like to see % formatting go away everntually*, other 
developers would not. In any case, I agree that it should not disappear 
until there is a foolproof conversion tool, probably custom written. I 
am working on other things.

* perhaps in 10 years?, when all 2.x code that is going to be converted 
has been converted



From jcasale at activenetwerx.com  Tue May 21 23:59:55 2013
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Wed, 22 May 2013 03:59:55 +0000
Subject: Case insensitive dict
Message-ID: <assp.08546b00eb.adcdc70a4aec40669f0b35387bd4b202@exch.activenetwerx.com>

I was doing some work with the ldap module and required a ci dict that was case
insensitive but case preserving. It turned out the cidict class they implemented was
broken with respect to pop, it is inherited and not re implemented to work. Before
I set about re-inventing the wheel, anyone know of a working implementation?

I noticed twisted has one but it seems to omit pop.

Thanks!
jlc

From steve+comp.lang.python at pearwood.info  Wed May 22 01:19:52 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 22 May 2013 05:19:52 GMT
Subject: Case insensitive dict
References: <mailman.1952.1369195266.3114.python-list@python.org>
Message-ID: <519c5578$0$1591$c3e8da3$76491128@news.astraweb.com>

On Wed, 22 May 2013 03:59:55 +0000, Joseph L. Casale wrote:

> I was doing some work with the ldap module and required a ci dict that
> was case insensitive but case preserving. It turned out the cidict class
> they implemented was broken with respect to pop, it is inherited and not
> re implemented to work. Before I set about re-inventing the wheel,
> anyone know of a working implementation?

class my_cidict(ldap.cidict):
    """Fix problems with pop."""
    def pop(self):
        # insert code here


You don't have to re-invent the entire wheel just to fix one broken 
spoke :-)

Other than that, no, I don't know of any case-insensitive but preserving 
dicts. If you do decide to write one from scratch, please consider 
releasing it as Open Source (I recommend GPL or MIT licences), either as 
a module on PyPI or as a recipe on ActiveState.

https://pypi.python.org/pypi
http://code.activestate.com/recipes/langs/python/



Thank you.






-- 
Steven


From cndesrosiers at gmail.com  Wed May 22 02:23:15 2013
From: cndesrosiers at gmail.com (C. N. Desrosiers)
Date: Tue, 21 May 2013 23:23:15 -0700 (PDT)
Subject: Newbie question about evaluating raw_input() responses
Message-ID: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>

Hi,

I'm just starting out with Python and to practice I am trying to write a script that can have a simple conversation with the user.

When I run the below code, it always ends up printing response to "if age > 18:" -- even if I enter a value below 18.

Can anyone point me to what I am doing wrong?  Many thanks in advance.

age=raw_input('Enter your age: ')
if age > 18:
    print ('Wow, %s. You can buy cigarettes.' % age)
else:
    print ('You are a young grasshopper.')


From fabiosantosart at gmail.com  Wed May 22 02:35:18 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Wed, 22 May 2013 07:35:18 +0100
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
Message-ID: <CAA=1kxS4Pu-92K5HzKtCCkeP1C8Kh-jXgfmGLM6UYHtsuRdfcA@mail.gmail.com>

You have to convert `age` to an integer. Use int() to do it. Then you can
compare it to other numbers and obtain the expected results.
On 22 May 2013 07:29, "C. N. Desrosiers" <cndesrosiers at gmail.com> wrote:

> Hi,
>
> I'm just starting out with Python and to practice I am trying to write a
> script that can have a simple conversation with the user.
>
> When I run the below code, it always ends up printing response to "if age
> > 18:" -- even if I enter a value below 18.
>
> Can anyone point me to what I am doing wrong?  Many thanks in advance.
>
> age=raw_input('Enter your age: ')
> if age > 18:
>     print ('Wow, %s. You can buy cigarettes.' % age)
> else:
>     print ('You are a young grasshopper.')
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From kevin.xgr at gmail.com  Wed May 22 02:52:30 2013
From: kevin.xgr at gmail.com (Kevin Xi)
Date: Tue, 21 May 2013 23:52:30 -0700 (PDT)
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
Message-ID: <c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>

On Wednesday, May 22, 2013 2:23:15 PM UTC+8, C. N. Desrosiers wrote:
> Hi,
> 
Hi,
> 
> I'm just starting out with Python and to practice I am trying to write a script that can have a simple conversation with the user.
> 
So you may want to search the doc before you ask: http://docs.python.org
> 
> When I run the below code, it always ends up printing response to "if age > 18:" -- even if I enter a value below 18.
> 
> 
> 
> Can anyone point me to what I am doing wrong?  Many thanks in advance.
> 
> 
> 
> age=raw_input('Enter your age: ')
> 
> if age > 18:
> 
>     print ('Wow, %s. You can buy cigarettes.' % age)
> 
> else:
> 
>     print ('You are a young grasshopper.')

You can either use `raw_input` to read data and convert it to right type, or use `input` to get an integer directly. Read this: http://docs.python.org/2/library/functions.html#raw_input
http://docs.python.org/2/library/functions.html#input

                                                                     Kevin


From rosuav at gmail.com  Wed May 22 03:19:06 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 22 May 2013 17:19:06 +1000
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
Message-ID: <CAPTjJmpN1Uqa-DzkVR72_XWyDtGF-XcZzcOcN6-ySX-akbavxA@mail.gmail.com>

On Wed, May 22, 2013 at 4:52 PM, Kevin Xi <kevin.xgr at gmail.com> wrote:
> On Wednesday, May 22, 2013 2:23:15 PM UTC+8, C. N. Desrosiers wrote:
>> age=raw_input('Enter your age: ')
>> if age > 18:
>
> You can either use `raw_input` to read data and convert it to right type, or use `input` to get an integer directly. Read this: http://docs.python.org/2/library/functions.html#raw_input
> http://docs.python.org/2/library/functions.html#input

No! No, please do NOT use input()! It does not return an integer; it
*evaluates* (that is, executes) the input.

>>> input('Enter your age: ')
Enter your age: 18
18
>>> input('Enter your age: ')
Enter your age: 1+2+4+5+6
18
>>> input('Enter your age: ')
Enter your age: sys.stdout.write("Hello, world!\n") or 18
Hello, world!
18
>>> input('Enter your age: ')
Enter your age: sys.exit(0)

This is almost certainly NOT what you want to have in your script. If
you want an integer, just pass it through int() as Fabio suggested.

Please do not use, or advocate using, this steam-powered Izzet goblin
hammer for cracking walnuts.

ChrisA


From alister.ware at ntlworld.com  Wed May 22 18:31:04 2013
From: alister.ware at ntlworld.com (Alister)
Date: Wed, 22 May 2013 22:31:04 GMT
Subject: Newbie question about evaluating raw_input() responses
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
Message-ID: <IGbnt.31113$LC7.15822@fx06.am4>

On Tue, 21 May 2013 23:52:30 -0700, Kevin Xi wrote:

> On Wednesday, May 22, 2013 2:23:15 PM UTC+8, C. N. Desrosiers wrote:
>> Hi,
>> 
> Hi,
>> 
>> I'm just starting out with Python and to practice I am trying to write
>> a script that can have a simple conversation with the user.
>> 
> So you may want to search the doc before you ask: http://docs.python.org
>> 
>> When I run the below code, it always ends up printing response to "if
>> age > 18:" -- even if I enter a value below 18.
>> 
>> 
>> 
>> Can anyone point me to what I am doing wrong?  Many thanks in advance.
>> 
>> 
>> 
>> age=raw_input('Enter your age: ')
>> 
>> if age > 18:
>> 
>>     print ('Wow, %s. You can buy cigarettes.' % age)
>> 
>> else:
>> 
>>     print ('You are a young grasshopper.')
> 
> You can either use `raw_input` to read data and convert it to right
> type, or use `input` to get an integer directly. Read this:
> http://docs.python.org/2/library/functions.html#raw_input
> http://docs.python.org/2/library/functions.html#input
> 
>                                                                      
Kevin

Please write out 1000 time (without using any form of loop)

"NEVER use input in python <3.0 it is EVIL"*

as Chris A point out it executes user input an can cause major damage 
(reformatting the hard disk is not impossible!)


-- 
Quality Control, n.:
	The process of testing one out of every 1,000 units coming off
	a production line to make sure that at least one out of 100 works.


From carlosnepomuceno at outlook.com  Wed May 22 18:55:59 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 01:55:59 +0300
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <IGbnt.31113$LC7.15822@fx06.am4>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>,
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>,
	<IGbnt.31113$LC7.15822@fx06.am4>
Message-ID: <BLU176-W7604EA3D422B9D1667EA6D7A90@phx.gbl>

----------------------------------------
> From: alister.ware at ntlworld.com
[...]
> Kevin
>
> Please write out 1000 time (without using any form of loop)
>
> "NEVER use input in python <3.0 it is EVIL"*
>
> as Chris A point out it executes user input an can cause major damage
> (reformatting the hard disk is not impossible!)
>

Indeed! input is eval(raw_input())! lol 		 	   		  

From kevin.xgr at gmail.com  Wed May 22 21:56:16 2013
From: kevin.xgr at gmail.com (Kevin Xi)
Date: Wed, 22 May 2013 18:56:16 -0700 (PDT)
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <IGbnt.31113$LC7.15822@fx06.am4>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
	<IGbnt.31113$LC7.15822@fx06.am4>
Message-ID: <4ede47a9-dc20-4509-bc5c-3095c0a6ffcb@googlegroups.com>

Oh yes, you guys are right. Thank you very much for warning me that.

On Thursday, May 23, 2013 6:31:04 AM UTC+8, Alister wrote:

> 
> as Chris A point out it executes user input an can cause major damage 
> 
> (reformatting the hard disk is not impossible!)
> 

It definitely can cause major damage! I try to input `os.system('rm -rf *')` and it really delete all stuff under the directory:(, I have never realized it can do that harm. Sorry for misleading you C. N. Desrosiers.


From steve+comp.lang.python at pearwood.info  Thu May 23 00:47:45 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 23 May 2013 04:47:45 GMT
Subject: Newbie question about evaluating raw_input() responses
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
	<IGbnt.31113$LC7.15822@fx06.am4>
Message-ID: <519d9f71$0$1591$c3e8da3$76491128@news.astraweb.com>

On Wed, 22 May 2013 22:31:04 +0000, Alister wrote:

> Please write out 1000 time (without using any form of loop)
> 
> "NEVER use input in python <3.0 it is EVIL"*
> 
> as Chris A point out it executes user input an can cause major damage
> (reformatting the hard disk is not impossible!)

Is he allowed to use eval instead of a loop?

print (eval("NEVER use input in python <3.0 it is EVIL\n"*1000))

*wink*


But all joking aside, eval is dangerous, yes, but it is not "evil". It 
needs to be handled with caution, but there are good uses for it. In 
fact, there are a few -- a very few -- things which can *only* be done 
with eval or exec. That's why it is part of the language! 

(I just wish that eval and exec where in a module, rather than built-in, 
to help discourage casual usage by beginners who don't know what they're 
doing.)

For example, collections.namedtuple uses eval to dynamically generate new 
classes on the fly from arguments given. But it is safe to use, because 
it has been designed by experts to be safe and tested in great detail.

So while it is right and proper to treat eval with great respect as a 
powerful (and therefore dangerous) tool, and avoid it whenever you don't 
*need* it, there is no reason to be irrational about it :-)



-- 
Steven


From rosuav at gmail.com  Thu May 23 02:04:09 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 16:04:09 +1000
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <519d9f71$0$1591$c3e8da3$76491128@news.astraweb.com>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
	<IGbnt.31113$LC7.15822@fx06.am4>
	<519d9f71$0$1591$c3e8da3$76491128@news.astraweb.com>
Message-ID: <CAPTjJmpUKhVNB_ET_Pz6YCmjKu_piqGOCbRerQ=ezfTMNRiJyA@mail.gmail.com>

On Thu, May 23, 2013 at 2:47 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> But all joking aside, eval is dangerous, yes, but it is not "evil". It
> needs to be handled with caution, but there are good uses for it. In
> fact, there are a few -- a very few -- things which can *only* be done
> with eval or exec. That's why it is part of the language!
>...
>
> So while it is right and proper to treat eval with great respect as a
> powerful (and therefore dangerous) tool, and avoid it whenever you don't
> *need* it, there is no reason to be irrational about it :-)

No need to be irrational about eval(), but I do agree that input()
should never be used. Especially now that Py3 has changed the meaning
of input(), it's potentially very confusing to call the old function;
be explicit and use eval(raw_input()) if you actually want that.

Quite apart from the extreme danger of eval'ing something tainted
(which isn't a problem if you KNOW the user's trusted - eg if you're
effectively writing an interactive interpreter for yourself), input()
is just too concealing; it's not obvious that code will be executed.

Above all, I don't want to see people advised to eval things as a
solution to simple problems. Maybe it's safe *right now*, but any
advice that solves today's problem will be used to solve tomorrow's
problem too, and tomorrow's problem will involve code going to someone
untrusted who suddenly gets full code execution.

But this is why we have a mailing list, not one-on-one advice. Kevin's
post is bound to get a follow-up, just as my posts are when I say
something incorrect. It gives that measure of extra confidence:
"Correct me if I'm wrong, but..." is implicitly prefixed to everything
:)

So Kevin, please don't get me wrong: I'm not hating on you, I'm not
wishing you hadn't posted. But I *will* speak strongly against the Py2
input() function. :)

Chris Angelico


From tjreedy at udel.edu  Thu May 23 03:11:21 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Thu, 23 May 2013 03:11:21 -0400
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <519d9f71$0$1591$c3e8da3$76491128@news.astraweb.com>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
	<IGbnt.31113$LC7.15822@fx06.am4>
	<519d9f71$0$1591$c3e8da3$76491128@news.astraweb.com>
Message-ID: <knkfeh$rr4$1@ger.gmane.org>

On 5/23/2013 12:47 AM, Steven D'Aprano wrote:
> On Wed, 22 May 2013 22:31:04 +0000, Alister wrote:
>
>> Please write out 1000 time (without using any form of loop)
>>
>> "NEVER use input in python <3.0 it is EVIL"*

> But all joking aside, eval is dangerous, yes, but it is not "evil".

He put that label on *input*, not eval -- I presume for hiding dangerous 
eval.




From rosuav at gmail.com  Thu May 23 03:20:19 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 17:20:19 +1000
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <knkfeh$rr4$1@ger.gmane.org>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
	<IGbnt.31113$LC7.15822@fx06.am4>
	<519d9f71$0$1591$c3e8da3$76491128@news.astraweb.com>
	<knkfeh$rr4$1@ger.gmane.org>
Message-ID: <CAPTjJmqAxFZUCq9CezwtdZYUYL+gfpEUADkzDn_9JiwyVcuCXg@mail.gmail.com>

On Thu, May 23, 2013 at 5:11 PM, Terry Jan Reedy <tjreedy at udel.edu> wrote:
> On 5/23/2013 12:47 AM, Steven D'Aprano wrote:
>>
>> On Wed, 22 May 2013 22:31:04 +0000, Alister wrote:
>>
>>> Please write out 1000 time (without using any form of loop)
>>>
>>> "NEVER use input in python <3.0 it is EVIL"*
>
>
>> But all joking aside, eval is dangerous, yes, but it is not "evil".
>
>
> He put that label on *input*, not eval -- I presume for hiding dangerous
> eval.

Aside: Why was PHP's /e regexp option ever implemented? I can
understand evalling inputted text - that's how you write an
interactive interpreter. But why would you arbitrarily eval the result
of a regexp replacement? That seems... really weird. Like building a
gun with a "Reverse" switch that fires the bullet down the butt
instead of the barrel.

ChrisA


From nobody at nowhere.com  Sat May 25 14:27:14 2013
From: nobody at nowhere.com (Nobody)
Date: Sat, 25 May 2013 19:27:14 +0100
Subject: Newbie question about evaluating raw_input() responses
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
	<IGbnt.31113$LC7.15822@fx06.am4>
	<519d9f71$0$1591$c3e8da3$76491128@news.astraweb.com>
	<knkfeh$rr4$1@ger.gmane.org>
	<mailman.1999.1369294009.3114.python-list@python.org>
Message-ID: <pan.2013.05.25.18.27.14.22000@nowhere.com>

On Thu, 23 May 2013 17:20:19 +1000, Chris Angelico wrote:

> Aside: Why was PHP's /e regexp option ever implemented?

Because it's a stupid idea, and that's the only requirement for a feature
to be implemented in PHP.



From rosuav at gmail.com  Sat May 25 14:33:06 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 04:33:06 +1000
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <pan.2013.05.25.18.27.14.22000@nowhere.com>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
	<IGbnt.31113$LC7.15822@fx06.am4>
	<519d9f71$0$1591$c3e8da3$76491128@news.astraweb.com>
	<knkfeh$rr4$1@ger.gmane.org>
	<mailman.1999.1369294009.3114.python-list@python.org>
	<pan.2013.05.25.18.27.14.22000@nowhere.com>
Message-ID: <CAPTjJmoE-XfaLAumdT2iFgtbmU4yOi5cn0R1yiPcQr0K91J1vw@mail.gmail.com>

On Sun, May 26, 2013 at 4:27 AM, Nobody <nobody at nowhere.com> wrote:
> On Thu, 23 May 2013 17:20:19 +1000, Chris Angelico wrote:
>
>> Aside: Why was PHP's /e regexp option ever implemented?
>
> Because it's a stupid idea, and that's the only requirement for a feature
> to be implemented in PHP.

Hey, don't be rude. I mean, not that it isn't true, but it's still
rude to say it.

Ah, who am I kidding. Be as rude as you like. I have to work with PHP all week.

ChrisA


From fabiosantosart at gmail.com  Sat May 25 18:11:45 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sat, 25 May 2013 23:11:45 +0100
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <CAPTjJmoE-XfaLAumdT2iFgtbmU4yOi5cn0R1yiPcQr0K91J1vw@mail.gmail.com>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<c8d5972d-9b11-4885-a68d-6ce1d0414718@googlegroups.com>
	<IGbnt.31113$LC7.15822@fx06.am4>
	<519d9f71$0$1591$c3e8da3$76491128@news.astraweb.com>
	<knkfeh$rr4$1@ger.gmane.org>
	<mailman.1999.1369294009.3114.python-list@python.org>
	<pan.2013.05.25.18.27.14.22000@nowhere.com>
	<CAPTjJmoE-XfaLAumdT2iFgtbmU4yOi5cn0R1yiPcQr0K91J1vw@mail.gmail.com>
Message-ID: <CAA=1kxRzKodpea3gDuR0my1AQ32_StM6xaOZoML3WnKVP0c6eQ@mail.gmail.com>

On 25 May 2013 19:37, "Chris Angelico" <rosuav at gmail.com> wrote:
> Ah, who am I kidding. Be as rude as you like. I have to work with PHP all
week.
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list

I have cried.
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From cndesrosiers at gmail.com  Wed May 22 02:52:41 2013
From: cndesrosiers at gmail.com (C. N. Desrosiers)
Date: Tue, 21 May 2013 23:52:41 -0700 (PDT)
Subject: Newbie question about evaluating raw_input() responses
In-Reply-To: <mailman.1954.1369204522.3114.python-list@python.org>
References: <534d7800-14c1-430b-85fb-dd703c2acc4d@googlegroups.com>
	<mailman.1954.1369204522.3114.python-list@python.org>
Message-ID: <98d36904-6429-4fd8-a65c-79edd4214632@googlegroups.com>

Muchas gracias!

On Wednesday, May 22, 2013 2:35:18 AM UTC-4, F?bio Santos wrote:
> You have to convert `age` to an integer. Use int() to do it. Then you can compare it to other numbers and obtain the expected results.
> 
> On 22 May 2013 07:29, "C. N. Desrosiers" <cndesr... at gmail.com> wrote:
> 
> Hi,
> 
> 
> 
> I'm just starting out with Python and to practice I am trying to write a script that can have a simple conversation with the user.
> 
> 
> 
> When I run the below code, it always ends up printing response to "if age > 18:" -- even if I enter a value below 18.
> 
> 
> 
> Can anyone point me to what I am doing wrong? ?Many thanks in advance.
> 
> 
> 
> age=raw_input('Enter your age: ')
> 
> if age > 18:
> 
> ? ? print ('Wow, %s. You can buy cigarettes.' % age)
> 
> else:
> 
> ? ? print ('You are a young grasshopper.')
> 
> --
> 
> http://mail.python.org/mailman/listinfo/python-list




From jldunn2000 at gmail.com  Wed May 22 04:46:42 2013
From: jldunn2000 at gmail.com (loial)
Date: Wed, 22 May 2013 01:46:42 -0700 (PDT)
Subject: Diagnosing socket "Connection reset by peer"
Message-ID: <038ecc3e-1272-46c0-84d5-556daeffbde0@googlegroups.com>

I have a sockets client that is connecting to a printer and occassionally getting the error "104 Connection reset by peer"

I have not been able to diagnose what is causing this. Is there any additional traceing I can do(either within my python code or on the network) to establish what is causing this error?

Currently I am simply trapping socket.erruor 

Python version is 2.6








From matt.walker.jones at gmail.com  Wed May 22 07:46:22 2013
From: matt.walker.jones at gmail.com (Matt Jones)
Date: Wed, 22 May 2013 06:46:22 -0500
Subject: Diagnosing socket "Connection reset by peer"
In-Reply-To: <038ecc3e-1272-46c0-84d5-556daeffbde0@googlegroups.com>
References: <038ecc3e-1272-46c0-84d5-556daeffbde0@googlegroups.com>
Message-ID: <CANuMAv8jnMv71+5aujTeVQr5p5sgkKK=-LKKFxsa0EEe1d8qew@mail.gmail.com>

This typically indicates that the "peer" at the other end of the tcp
connection severed the session without the typical FIN packet.  If you're
treating the printer as a "blackbox" then there really isn't anything you
can do here except catch the exception and attempt to reconnect.

*Matt Jones*


On Wed, May 22, 2013 at 3:46 AM, loial <jldunn2000 at gmail.com> wrote:

> I have a sockets client that is connecting to a printer and occassionally
> getting the error "104 Connection reset by peer"
>
> I have not been able to diagnose what is causing this. Is there any
> additional traceing I can do(either within my python code or on the
> network) to establish what is causing this error?
>
> Currently I am simply trapping socket.erruor
>
> Python version is 2.6
>
>
>
>
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From davea at davea.name  Wed May 22 08:50:24 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 22 May 2013 08:50:24 -0400
Subject: Diagnosing socket "Connection reset by peer"
In-Reply-To: <038ecc3e-1272-46c0-84d5-556daeffbde0@googlegroups.com>
References: <038ecc3e-1272-46c0-84d5-556daeffbde0@googlegroups.com>
Message-ID: <519CBF10.8030604@davea.name>

On 05/22/2013 04:46 AM, loial wrote:
>    <SNIP>
>
> .... Is there any additional traceing I can do(either within my python code or on the network) to establish what is causing this error?
>


Try using Wireshark.  It can do a remarkable job of filtering, 
capturing, and analyzing packets.  It can also read and write pcap 
files, which you could either save for later analysis, or send to 
someone who might help.  (Note - unfiltered pcap files can be very large 
on a busy network, but if you can quiet other traffic, you may not need 
to filter at all.)


-- 
DaveA


From grahn+nntp at snipabacken.se  Wed May 22 15:44:15 2013
From: grahn+nntp at snipabacken.se (Jorgen Grahn)
Date: 22 May 2013 19:44:15 GMT
Subject: Diagnosing socket "Connection reset by peer"
References: <038ecc3e-1272-46c0-84d5-556daeffbde0@googlegroups.com>
	<mailman.1963.1369227039.3114.python-list@python.org>
Message-ID: <slrnkpq80d.3jn.grahn+nntp@frailea.sa.invalid>

On Wed, 2013-05-22, Dave Angel wrote:
> On 05/22/2013 04:46 AM, loial wrote:
>>    <SNIP>
>>
>> .... Is there any additional traceing I can do(either within my
>> python code or on the network) to establish what is causing this
>> error?
>
> Try using Wireshark.  It can do a remarkable job of filtering, 
> capturing, and analyzing packets.  It can also read and write pcap 
> files, which you could either save for later analysis, or send to 
> someone who might help.

Or use tcpdump, which has a text interface so you can show the problem
in a text medium like Usenet.

> (Note - unfiltered pcap files can be very large 
> on a busy network, but if you can quiet other traffic, you may not need 
> to filter at all.)

Or simply filter.  It's not hard -- the capture filter
"host my-printer-hostname-or-address" is enough.

/Jorgen

-- 
  // Jorgen Grahn <grahn@  Oo  o.   .     .
\X/     snipabacken.se>   O  o   .


From invalid at invalid.invalid  Wed May 22 15:55:39 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 22 May 2013 19:55:39 +0000 (UTC)
Subject: Diagnosing socket "Connection reset by peer"
References: <038ecc3e-1272-46c0-84d5-556daeffbde0@googlegroups.com>
	<mailman.1963.1369227039.3114.python-list@python.org>
	<slrnkpq80d.3jn.grahn+nntp@frailea.sa.invalid>
Message-ID: <knj7rr$7ai$1@reader1.panix.com>

On 2013-05-22, Jorgen Grahn <grahn+nntp at snipabacken.se> wrote:
> On Wed, 2013-05-22, Dave Angel wrote:
>> On 05/22/2013 04:46 AM, loial wrote:
>>>    <SNIP>
>>>
>>> .... Is there any additional traceing I can do(either within my
>>> python code or on the network) to establish what is causing this
>>> error?
>>
>> Try using Wireshark.  It can do a remarkable job of filtering, 
>> capturing, and analyzing packets.  It can also read and write pcap 
>> files, which you could either save for later analysis, or send to 
>> someone who might help.
>
> Or use tcpdump, which has a text interface so you can show the problem
> in a text medium like Usenet.

There's also tshark, which is sort of a command-line version of
wireshark.

http://www.wireshark.org/docs/man-pages/tshark.html

>> (Note - unfiltered pcap files can be very large on a busy network,
>> but if you can quiet other traffic, you may not need to filter at
>> all.)
>
> Or simply filter.  It's not hard -- the capture filter "host
> my-printer-hostname-or-address" is enough.

Indeed.  Even a simple filter can make life several orders of
magnitude easier.  If filtering by IP address isn't enough, the next
step is usually to add a port number filter...

-- 
Grant Edwards               grant.b.edwards        Yow! Of course, you
                                  at               UNDERSTAND about the PLAIDS
                              gmail.com            in the SPIN CYCLE --


From grahn+nntp at snipabacken.se  Wed May 22 15:54:05 2013
From: grahn+nntp at snipabacken.se (Jorgen Grahn)
Date: 22 May 2013 19:54:05 GMT
Subject: Diagnosing socket "Connection reset by peer"
References: <038ecc3e-1272-46c0-84d5-556daeffbde0@googlegroups.com>
	<mailman.1960.1369223210.3114.python-list@python.org>
Message-ID: <slrnkpq8is.3jn.grahn+nntp@frailea.sa.invalid>

On Wed, 2013-05-22, Matt Jones wrote:
> On Wed, May 22, 2013 at 3:46 AM, loial <jldunn2000 at gmail.com> wrote:
>
>> I have a sockets client that is connecting to a printer and occassionally
>> getting the error "104 Connection reset by peer"
>>
>> I have not been able to diagnose what is causing this. Is there any
>> additional traceing I can do(either within my python code or on the
>> network) to establish what is causing this error?
>>
>> Currently I am simply trapping socket.erruor
>>
>> Python version is 2.6

> This typically indicates that the "peer" at the other end of the tcp
> connection severed the session without the typical FIN packet.

I.e. by sending a RST (reset) instead.  Yes, that's what "Connection
reset by peer" means.  I don't think there are any other causes for
this signal.

A server application can cause a reset explicitly, or if it crashes
the OS will send one for it, as part of the resource cleanup.

Also, if you're behind a cheap NATing gateway, I think it may send
fake RSTs if it has lost track of the TCP session.

> If you're
> treating the printer as a "blackbox" then there really isn't anything you
> can do here except catch the exception and attempt to reconnect.

Yes.  Note that there *may* be some uncertainty re: "did the printer
process the last request before the reset or not?" E.g. I wouldn't
endlessly retry printing a 100-page document in that case.

/Jorgen

-- 
  // Jorgen Grahn <grahn@  Oo  o.   .     .
\X/     snipabacken.se>   O  o   .


From absalom at emet.tnk  Wed May 22 08:10:01 2013
From: absalom at emet.tnk (Absalom K.)
Date: 22 May 2013 12:10:01 GMT
Subject: Python Windows release and encoding
Message-ID: <519cb599$0$2290$426a74cc@news.free.fr>

Hi, I am working on Linux; a friend of mine sends to me python files from
his Windows release. He uses the editor coming with the release; he runs
his code from the editor by using a menu (or some F5 key I think).

He doesn't declare any encoding in his source file; when I want to try
his code, I have an error since he obviously uses non-ascii characters.
As far as I can see, he uses utf8 without knowing it. I add the UTF8
declaration, run the code, and everything is fine.

Then I tell him to add the utf-8 declaration; but now he has an error
when running his file from the Windows editor.

Finally, he told me he could run the file by declaring the latin-1
encoding.

But I want to understand exactly:
  a) what is the encoding used by the editor coming in the Windows release?
  b) why doesn't he need to declare the encoding (I need it on Linux for
     the very same files)?

Best regards, ak.


From __peter__ at web.de  Wed May 22 08:39:15 2013
From: __peter__ at web.de (Peter Otten)
Date: Wed, 22 May 2013 14:39:15 +0200
Subject: Python Windows release and encoding
References: <519cb599$0$2290$426a74cc@news.free.fr>
Message-ID: <knie8q$k07$1@ger.gmane.org>

Absalom K. wrote:

> Hi, I am working on Linux; a friend of mine sends to me python files from
> his Windows release. He uses the editor coming with the release; he runs
> his code from the editor by using a menu (or some F5 key I think).
> 
> He doesn't declare any encoding in his source file; when I want to try
> his code, I have an error since he obviously uses non-ascii characters.
> As far as I can see, he uses utf8 without knowing it. I add the UTF8
> declaration, run the code, and everything is fine.
> 
> Then I tell him to add the utf-8 declaration; but now he has an error
> when running his file from the Windows editor.
> 
> Finally, he told me he could run the file by declaring the latin-1
> encoding.
> 
> But I want to understand exactly:
>   a) what is the encoding used by the editor coming in the Windows
>   release? b) why doesn't he need to declare the encoding (I need it on
>   Linux for
>      the very same files)?
> 
> Best regards, ak.

Your friend may be using an old version of Python. Quoting

<http://www.python.org/dev/peps/pep-0263/>

"""
    For backwards-compatibility with existing code which currently
    uses non-ASCII in string literals without declaring an encoding,
    the implementation will be introduced in two phases:

    1. Allow non-ASCII in string literals and comments, by internally
       treating a missing encoding declaration as a declaration of
       "iso-8859-1". This will cause arbitrary byte strings to
       correctly round-trip between step 2 and step 5 of the
       processing, and provide compatibility with Python 2.2 for
       Unicode literals that contain non-ASCII bytes.

       A warning will be issued if non-ASCII bytes are found in the
       input, once per improperly encoded input file.

    2. Remove the warning, and change the default encoding to "ascii".

    [...]

    Implementation of steps 1 and 2 above were completed in 2.3,
    except for changing the default encoding to "ascii".

    The default encoding was set to "ascii" in version 2.5.
 """



From cts.private.yahoo at gmail.com  Wed May 22 11:32:49 2013
From: cts.private.yahoo at gmail.com (Charles Smith)
Date: Wed, 22 May 2013 08:32:49 -0700 (PDT)
Subject: subclassing from unittest
Message-ID: <07786a18-bb9f-4434-823c-d0fe00f858b0@cl9g2000vbb.googlegroups.com>

Hi,

I'd like to subclass from unittest.TestCase.  I observed something
interesting and wonder if anyone can explain what's going on... some
subclasses create  null tests.

I can create this subclass and the test works:

  class StdTestCase (unittest.TestCase):
      blahblah

and I can create this subsubclass and the test works:

  class aaaTestCase (StdTestCase):
      moreblahblah

but if I create this subsubclass (or any where the first letter is
capital):

  class AaaTestCase (StdTestCase):
      differentblahblah

the test completes immediately without any work being done.

I suspect that the answer is in the prefix printed out by the test.  I
have diffed both the long output (tests works, on the left) and the
short output (null test, on the right):

test
(TC_02.TestCase_F_0000_ULLA05_xxxxxxxx_AM_Tx) ...                  <
test suite has  <unittest.TestSuite tests=[<unittest.TestSuite
tests=[]>,       test suite has  <unittest.TestSuite
tests=[<unittest.TestSuite tests=[]>,
 
>    <unittest.TestSuite tests=[]>,
 <unittest.TestSuite
tests=[<TC_02.TestCase_F_0000_ULLA05_xxxxxxxx_AM
<unittest.TestSuite tests=[<TC_02.TestCase_F_0000_ULLA05_xxxxxxxx_AM
 <unittest.TestSuite
tests=[<TC_02.TestCase_F_0001_ULLA10_xxxxxxxx_AM
<unittest.TestSuite tests=[<TC_02.TestCase_F_0001_ULLA10_xxxxxxxx_AM
 <unittest.TestSuite
tests=[<TC_02.TestCase_F_0002_ULLA20_xxxxxxxx_AM
<unittest.TestSuite tests=[<TC_02.TestCase_F_0002_ULLA20_xxxxxxxx_AM
 <unittest.TestSuite
tests=[<TC_02.TestCase_F_0003_ULLA05_xxxxxxxx_UM
<unittest.TestSuite tests=[<TC_02.TestCase_F_0003_ULLA05_xxxxxxxx_UM
 <unittest.TestSuite
tests=[<TC_02.TestCase_F_0005_ULLA10_xxxxxxxx_UM
<unittest.TestSuite tests=[<TC_02.TestCase_F_0005_ULLA10_xxxxxxxx_UM
 <unittest.TestSuite
tests=[<TC_02.TestCase_F_0006_ULLA20_xxxxxxxx_UM   |
<unittest.TestSuite tests=[<TC_02.TestCase_F_0006_ULLA20_xxxxxxxx_UM
 <unittest.TestSuite
tests=[]>]>                                        <
 
>   ---------->  test_api_socket:the address specified is:  127.0.0.1
 
>
 
>
 
>
 
>
----------------------------------------------------------------------
 
>   Ran 0 tests in 0.000s
 
>
 
>   OK


I see an empty test somehow gets sorted to the beginning of the list.
How could that be a result of whether the first letter of the class is
capitalized or not?

Thanks in advance...
cts

--------------------------------------------------------
http://www.creative-telcom-solutions.de


From cts.private.yahoo at gmail.com  Wed May 22 11:47:41 2013
From: cts.private.yahoo at gmail.com (Charles Smith)
Date: Wed, 22 May 2013 08:47:41 -0700 (PDT)
Subject: subclassing from unittest
References: <07786a18-bb9f-4434-823c-d0fe00f858b0@cl9g2000vbb.googlegroups.com>
Message-ID: <4adefe8b-d41c-488d-a695-53a62c497b91@q8g2000vbl.googlegroups.com>

On 22 Mai, 17:32, Charles Smith <cts.private.ya... at gmail.com> wrote:
> Hi,
>
> I'd like to subclass from unittest.TestCase. ?I observed something
> interesting and wonder if anyone can explain what's going on... some
> subclasses create ?null tests.
>
> I can create this subclass and the test works:
>
> ? class StdTestCase (unittest.TestCase):
> ? ? ? blahblah
>
> and I can create this subsubclass and the test works:
>
> ? class aaaTestCase (StdTestCase):
> ? ? ? moreblahblah
>
> but if I create this subsubclass (or any where the first letter is
> capital):
>
> ? class AaaTestCase (StdTestCase):
> ? ? ? differentblahblah
>
> the test completes immediately without any work being done.
>
> I suspect that the answer is in the prefix printed out by the test. ?I
> have diffed both the long output (tests works, on the left) and the
> short output (null test, on the right):
>
> test
> (TC_02.TestCase_F_0000_ULLA05_xxxxxxxx_AM_Tx) ... ? ? ? ? ? ? ? ? ?<
> test suite has ?<unittest.TestSuite tests=[<unittest.TestSuite
> tests=[]>, ? ? ? test suite has ?<unittest.TestSuite
> tests=[<unittest.TestSuite tests=[]>,
>
> > ? ?<unittest.TestSuite tests=[]>,
>
> ?<unittest.TestSuite
> tests=[<TC_02.TestCase_F_0000_ULLA05_xxxxxxxx_AM
> <unittest.TestSuite tests=[<TC_02.TestCase_F_0000_ULLA05_xxxxxxxx_AM
> ?<unittest.TestSuite
> tests=[<TC_02.TestCase_F_0001_ULLA10_xxxxxxxx_AM
> <unittest.TestSuite tests=[<TC_02.TestCase_F_0001_ULLA10_xxxxxxxx_AM
> ?<unittest.TestSuite
> tests=[<TC_02.TestCase_F_0002_ULLA20_xxxxxxxx_AM
> <unittest.TestSuite tests=[<TC_02.TestCase_F_0002_ULLA20_xxxxxxxx_AM
> ?<unittest.TestSuite
> tests=[<TC_02.TestCase_F_0003_ULLA05_xxxxxxxx_UM
> <unittest.TestSuite tests=[<TC_02.TestCase_F_0003_ULLA05_xxxxxxxx_UM
> ?<unittest.TestSuite
> tests=[<TC_02.TestCase_F_0005_ULLA10_xxxxxxxx_UM
> <unittest.TestSuite tests=[<TC_02.TestCase_F_0005_ULLA10_xxxxxxxx_UM
> ?<unittest.TestSuite
> tests=[<TC_02.TestCase_F_0006_ULLA20_xxxxxxxx_UM ? |
> <unittest.TestSuite tests=[<TC_02.TestCase_F_0006_ULLA20_xxxxxxxx_UM
> ?<unittest.TestSuite
> tests=[]>]> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?<
>
> > ? ----------> ?test_api_socket:the address specified is: ?127.0.0.1
>
> ----------------------------------------------------------------------
>
> > ? Ran 0 tests in 0.000s
>
> > ? OK
>
> I see an empty test somehow gets sorted to the beginning of the list.
> How could that be a result of whether the first letter of the class is
> capitalized or not?
>
> Thanks in advance...
> cts
>
> --------------------------------------------------------http://www.creative-telcom-solutions.de


Unfortunately, the side-by-side diff didn't come out so well  ...

---------------------------------------
http://www.creative-telcom-solutions.de


From tjreedy at udel.edu  Wed May 22 17:29:23 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Wed, 22 May 2013 17:29:23 -0400
Subject: subclassing from unittest
In-Reply-To: <07786a18-bb9f-4434-823c-d0fe00f858b0@cl9g2000vbb.googlegroups.com>
References: <07786a18-bb9f-4434-823c-d0fe00f858b0@cl9g2000vbb.googlegroups.com>
Message-ID: <knjdbb$so3$1@ger.gmane.org>

On 5/22/2013 11:32 AM, Charles Smith wrote:

Have you red this? I will suggest some specifics.
http://www.catb.org/esr/faqs/smart-questions.html

> I'd like to subclass from unittest.TestCase.

What version of Python.

 > I observed something interesting and wonder if anyone can explain 
what's going on... some
> subclasses create  null tests.
>
> I can create this subclass and the test works:

What does 'works' mean?

>    class StdTestCase (unittest.TestCase):
>        blahblah

I bet that this (and the rest of your 'code' is not what you actually 
ran. Unless blahblah is bound (to what?), this fails with NameError.
Give us what you ran so we can run it too, and modify it.

> and I can create this subsubclass and the test works:
>
>    class aaaTestCase (StdTestCase):
>        moreblahblah
>
> but if I create this subsubclass (or any where the first letter is
> capital):
>
>    class AaaTestCase (StdTestCase):
>        differentblahblah
>
> the test completes immediately without any work being done.

What does this mean? I see no difference with the following

import unittest
class StdTestCase (unittest.TestCase): pass
class lowerSub(StdTestCase): pass
class UpperSub(StdTestCase): pass

unittest.main(verbosity=2, exit=False)

# prints (3.3)
----------------------------------------------------------------------
Ran 0 tests in 0.000s

OK

Same as before the subclasses were added.

--
Terry Jan Reedy




From ulrich.eckhardt at dominolaser.com  Thu May 23 02:58:51 2013
From: ulrich.eckhardt at dominolaser.com (Ulrich Eckhardt)
Date: Thu, 23 May 2013 08:58:51 +0200
Subject: subclassing from unittest
In-Reply-To: <07786a18-bb9f-4434-823c-d0fe00f858b0@cl9g2000vbb.googlegroups.com>
References: <07786a18-bb9f-4434-823c-d0fe00f858b0@cl9g2000vbb.googlegroups.com>
Message-ID: <bar07a-pca.ln1@satorlaser.homedns.org>

Am 22.05.2013 17:32, schrieb Charles Smith:
> I'd like to subclass from unittest.TestCase.  I observed something
> interesting and wonder if anyone can explain what's going on... some
> subclasses create  null tests.

I can perhaps guess what's going on, though Terry is right: Your 
question isn't very helpful and informative.


> I can create this subclass and the test works:
>
>    class StdTestCase (unittest.TestCase):
>        blahblah
>
> and I can create this subsubclass and the test works:
>
>    class aaaTestCase (StdTestCase):
>        moreblahblah
>
> but if I create this subsubclass (or any where the first letter is
> capital):
>
>    class AaaTestCase (StdTestCase):
>        differentblahblah
>
> the test completes immediately without any work being done.

Well, per PEP 8, classes use CamelCaps, so your naming might break 
automatic test discovery. Then, there might be another thing that could 
cause this, and that is that if you have an intermediate class derived 
from unittest.TestCase, that class on its own will be considered as test 
case! If this is not what you want but you still want common 
functionality in a baseclass, create a mixin and then derive from both 
the mixin and unittest.TestCase for the actual test cases.

Good luck!

Uli



From roy at panix.com  Thu May 23 08:43:59 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 23 May 2013 08:43:59 -0400
Subject: subclassing from unittest
References: <07786a18-bb9f-4434-823c-d0fe00f858b0@cl9g2000vbb.googlegroups.com>
	<bar07a-pca.ln1@satorlaser.homedns.org>
Message-ID: <roy-63E1C3.08435923052013@news.panix.com>

In article <bar07a-pca.ln1 at satorlaser.homedns.org>,
 Ulrich Eckhardt <ulrich.eckhardt at dominolaser.com> wrote:

> if you have an intermediate class derived 
> from unittest.TestCase, that class on its own will be considered as test 
> case! If this is not what you want but you still want common 
> functionality in a baseclass, create a mixin and then derive from both 
> the mixin and unittest.TestCase for the actual test cases.

Or, try another trick I picked up somewhere.  When you're done defining 
your test classes, delete the intermediate base class, so it won't be 
autodiscovered!

class MyBaseTestClass(unittest.TestCase):
   pass

class MyRealTest1(MyBaseTestClass):
   pass

class MyRealTest2(MyBaseTestCalss):
   pass

del MyBaseTestClass


From tjreedy at udel.edu  Thu May 23 15:42:35 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Thu, 23 May 2013 15:42:35 -0400
Subject: subclassing from unittest
In-Reply-To: <bar07a-pca.ln1@satorlaser.homedns.org>
References: <07786a18-bb9f-4434-823c-d0fe00f858b0@cl9g2000vbb.googlegroups.com>
	<bar07a-pca.ln1@satorlaser.homedns.org>
Message-ID: <knlrf1$eft$1@ger.gmane.org>

On 5/23/2013 2:58 AM, Ulrich Eckhardt wrote:

> Well, per PEP 8, classes use CamelCaps, so your naming might break
> automatic test discovery. Then, there might be another thing that could
> cause this, and that is that if you have an intermediate class derived
> from unittest.TestCase, that class on its own will be considered as test
> case! If this is not what you want but you still want common
> functionality in a baseclass, create a mixin and then derive from both
> the mixin and unittest.TestCase for the actual test cases.

This is now standard practice, gradually being implemented everywhere in 
the CPython test suite, for testing C and Py versions of a module.

class TestXyz():
   mod = None
   <test_a, etc, methods>

class TestXyz_C(TestXyz, TextCase):  # Test C version
   mod = support.import_fresh_module('_xyz')  # approximately right

class TestXyz_Py(TestXyz, TextCase):  # Test Python version
   mod = support.import_fresh('xyz')

This minimizes duplication and ensures that both implementations get 
exactly the same tests.

tjr




From wilkeira at gmail.com  Wed May 22 12:13:19 2013
From: wilkeira at gmail.com (Keira Wilson)
Date: Thu, 23 May 2013 01:13:19 +0900
Subject: file I/O and arithmetic calculation
Message-ID: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>

Dear all,

I would appreciate if someone could write a simple python code for the
purpose below:

I have five text files each of 10 columns by 10 rows as follows:

file_one = 'C:/test/1.txt'
file_two = 'C:/test/2.txt' . . .
file_five = 'C:/test/5.txt'

 I want to calculate the mean of first row (10 elements) for each file (5
files), if mean of first column (10 elements) of each file (5 files) is 50.

Thank you in advance.

Keira
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From breamoreboy at yahoo.co.uk  Wed May 22 12:23:43 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 22 May 2013 17:23:43 +0100
Subject: file I/O and arithmetic calculation
In-Reply-To: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
Message-ID: <knirdr$jj9$1@ger.gmane.org>

On 22/05/2013 17:13, Keira Wilson wrote:
> Dear all,
>
> I would appreciate if someone could write a simple python code for the
> purpose below:
>
> I have five text files each of 10 columns by 10 rows as follows:
>
>
> |file_one=  'C:/test/1.txt'
> file_two=  'C:/test/2.txt'
> .  .  .
> file_five=  'C:/test/5.txt'|
>
> I want to calculate the mean of first row (10 elements) for each file (5
> files), if mean of first column (10 elements) of each file (5 files) is 50.
>
> Thank you in advance.
>
> Keira
>

Sorry but we don't do homework.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From carlosnepomuceno at outlook.com  Wed May 22 17:05:15 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 00:05:15 +0300
Subject: file I/O and arithmetic calculation
In-Reply-To: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
Message-ID: <BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>

Funny! I made a lot of assumptions regarding your requirements specification. Let me know if it isn't what you need:

### 1strow_average.py ###
#Assuming you have CSV (comma separated values) files such as:
#1.txt = '0,1,2,3,4,5,6,7,8,9\n' \
#??????? '10,11,12,13,14,15,16,17,18,19\n' \
#??????? '20,21,22,23,24,25,26,27,28,29\n' ...
#
# Usage: contents[file][row][column]
# contents[0]?????? : file '1.txt'
# contents[1][2]??? : 3rd row of file '2.txt'
# contents[3][4][5] : 6th column of 5th row of file '4.txt'
# len(contents)???? : quantity of files
# len(contents[4])? : quantity of lines in file '5.txt'
# len(contents[4][0]: quantity of values in the 1st line of file '5.txt'

filenames = ['1.txt', '2.txt', '3.txt', '4.txt', '5.txt']
contents? = [[[int(z) for z in y.split(',')] for y in open(x).read().split()] for x in filenames]
s1c? = [sum([r[0] for r in f]) for f in contents]
a1r? = [sum(f[0])/float(len(f[0])) for f in contents]
print '\n'.join([x for x in ['File "{}" has 1st row average = {:.2f}'.format(n,a1r[i]) if s1c[i]==50 else '' for i,n in enumerate(filenames)] if x])


________________________________
> From: wilkeira at gmail.com 
> Date: Thu, 23 May 2013 01:13:19 +0900 
> Subject: file I/O and arithmetic calculation 
> To: python-list at python.org 
>  
>  
> Dear all, 
>  
> I would appreciate if someone could write a simple python code for the  
> purpose below: 
>  
> I have five text files each of 10 columns by 10 rows as follows: 
>  
>  
>  
> file_one = 'C:/test/1.txt' 
> file_two = 'C:/test/2.txt' 
> . . . 
> file_five = 'C:/test/5.txt' 
>  
> I want to calculate the mean of first row (10 elements) for each file  
> (5 files), if mean of first column (10 elements) of each file (5  
> files) is 50. 
>  
> Thank you in advance. 
>  
> Keira 
>  
>  
> -- http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From oscar.j.benjamin at gmail.com  Wed May 22 19:43:08 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 23 May 2013 00:43:08 +0100
Subject: file I/O and arithmetic calculation
In-Reply-To: <BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>
Message-ID: <CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>

On 22 May 2013 22:05, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
>
> filenames = ['1.txt', '2.txt', '3.txt', '4.txt', '5.txt']
> contents  = [[[int(z) for z in y.split(',')] for y in open(x).read().split()] for x in filenames]
> s1c  = [sum([r[0] for r in f]) for f in contents]
> a1r  = [sum(f[0])/float(len(f[0])) for f in contents]
> print '\n'.join([x for x in ['File "{}" has 1st row average = {:.2f}'.format(n,a1r[i]) if s1c[i]==50 else '' for i,n in enumerate(filenames)] if x])

Do you find this code easy to read? I wouldn't write something like
this and I certainly wouldn't use it when explaining something to a
beginner.

Rather than repeated list comprehensions you should consider using a
single loop e.g.:

for filename in filenames:
    # process each file

This will make the code a lot simpler.


Oscar


From carlosnepomuceno at outlook.com  Wed May 22 19:49:31 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 02:49:31 +0300
Subject: file I/O and arithmetic calculation
In-Reply-To: <CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>,
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>,
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>
Message-ID: <BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>

----------------------------------------
> From: oscar.j.benjamin at gmail.com
[...]
>
> Do you find this code easy to read? I wouldn't write something like
> this and I certainly wouldn't use it when explaining something to a
> beginner.
>
> Rather than repeated list comprehensions you should consider using a
> single loop e.g.:
>
> for filename in filenames:
> # process each file
>
> This will make the code a lot simpler.
>
>
> Oscar

Indeed, but for that you can use Pascal.

List comprehensions it's what Python does best!

The code is pretty obvious to me, I mean there's no obfuscation at all. 		 	   		  

From carlosnepomuceno at outlook.com  Wed May 22 19:57:21 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 02:57:21 +0300
Subject: file I/O and arithmetic calculation
In-Reply-To: <BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>,
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>,
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>,
	<BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>
Message-ID: <BLU176-W15F4D27196E93261F28552D7A90@phx.gbl>

># contents[3][4][5] : 6th column of 5th row of file '4.txt'

BTW, it should read

# contents[3][4][5] : 6th value of 5th row of file '4.txt' 		 	   		  

From oscar.j.benjamin at gmail.com  Wed May 22 20:34:37 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 23 May 2013 01:34:37 +0100
Subject: file I/O and arithmetic calculation
In-Reply-To: <BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>
	<BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>
Message-ID: <CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>

On 23 May 2013 00:49, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
>
> The code is pretty obvious to me, I mean there's no obfuscation at all.

I honestly can't tell if you're joking.


From carlosnepomuceno at outlook.com  Wed May 22 20:37:52 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 03:37:52 +0300
Subject: file I/O and arithmetic calculation
In-Reply-To: <CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>,
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>,
	<BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>,
	<CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>
Message-ID: <BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>

----------------------------------------
> From: oscar.j.benjamin at gmail.com
> Date: Thu, 23 May 2013 01:34:37 +0100
> Subject: Re: file I/O and arithmetic calculation
> To: carlosnepomuceno at outlook.com
> CC: python-list at python.org
>
> On 23 May 2013 00:49, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
>>
>> The code is pretty obvious to me, I mean there's no obfuscation at all.
>
> I honestly can't tell if you're joking.

I'm not! lol 		 	   		  

From carlosnepomuceno at outlook.com  Wed May 22 23:15:58 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 06:15:58 +0300
Subject: file I/O and arithmetic calculation
In-Reply-To: <BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>,
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>,
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>,
	<BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>,
	<CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>,
	<BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>
Message-ID: <BLU176-W34475DEC9894A483FC75C0D7AA0@phx.gbl>

The last line of my noob piece can be improved. So this is it:

### 1strow_average.py ###
#Assuming you have CSV (comma separated values) files such as:
#1.txt = '0,1,2,3,4,5,6,7,8,9\n' \
#??????? '10,11,12,13,14,15,16,17,18,19\n' \
#??????? '20,21,22,23,24,25,26,27,28,29\n' ...
#
# Usage: contents[file][row][column]
# contents[0]?????? : file '1.txt'
# contents[1][2]??? : 3rd row of file '2.txt'
# contents[3][4][5] : value on the 6th column of 5th row of file '4.txt'
# len(contents)???? : quantity of files
# len(contents[4])? : quantity of lines in file '5.txt'
# len(contents[4][0]: quantity of values in the 1st line of file '5.txt'

filenames = ['1.txt', '2.txt', '3.txt', '4.txt', '5.txt']
contents? = [[[int(z) for z in y.split(',')] for y in open(x).read().split()] for x in filenames]
s1c? = [sum([r[0] for r in f]) for f in contents]
a1r? = [sum(f[0])/float(len(f[0])) for f in contents]
print '\n'.join(['File "{}" has 1st row average = {:.2f}'.format(n,a1r[i]) for i,n in enumerate(filenames) if s1c[i]==50]) 		 	   		  

From oscar.j.benjamin at gmail.com  Thu May 23 06:37:18 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 23 May 2013 11:37:18 +0100
Subject: file I/O and arithmetic calculation
In-Reply-To: <BLU176-W34475DEC9894A483FC75C0D7AA0@phx.gbl>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>
	<BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>
	<CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>
	<BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>
	<BLU176-W34475DEC9894A483FC75C0D7AA0@phx.gbl>
Message-ID: <CAHVvXxQSs_TgebahE0KT2UEa2Mg1R-LBjiKNGqS0scM6zm67Og@mail.gmail.com>

On 23 May 2013 04:15, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> The last line of my noob piece can be improved. So this is it:

Most of it can be improved.

> filenames = ['1.txt', '2.txt', '3.txt', '4.txt', '5.txt']
> contents  = [[[int(z) for z in y.split(',')] for y in open(x).read().split()] for x in filenames]
> s1c  = [sum([r[0] for r in f]) for f in contents]
> a1r  = [sum(f[0])/float(len(f[0])) for f in contents]
> print '\n'.join(['File "{}" has 1st row average = {:.2f}'.format(n,a1r[i]) for i,n in enumerate(filenames) if s1c[i]==50])

You're writing repeated list comprehensions that feed into one another
like this:

list2 = [func1(x) for x in list1]
list3 = [func2(y) for y in list2]
list4 = [func3(y) for y in list2]

In this case it is usually better to write a single loop

for x in list1:
    y = func1(x)
    v = func2(y)
    w = func3(y)

With that your code becomes:

filenames = ['1.txt', '2.txt', '3.txt', '4.txt', '5.txt']
for filename in filenames:
    contents  = [[int(z) for z in y.split(',')] for y in
open(filename).read().split()]
    s1c  = sum([r[0] for r in contents])
    a1r  = sum(f[0])/float(len(contents[0]))
    if s1c == 50:
        print('File "{}" has 1st row average = {:.2f}'.format(filename,a1r))

However you shouldn't really be doing open(x).read().split() part. You
should use the with statement to open the files:

with open(filename, 'rb') as inputfile:
    contents = [map(int, line.split()) for line in inputfile]

Of course if you don't have so many list comprehensions in your code
then your lines will be shorter and you won't feel so much pressure to
use such short variable names. It's also better to define a mean
function as it makes it clearer to read:

# Needed by the mean() function in Python 2.x
from  __future__ import division

def mean(numbers):
    return sum(numbers) / len(numbers)

filenames = ['1.txt', '2.txt', '3.txt', '4.txt', '5.txt']

for filename in filenames:
    with open(filename, 'rb') as inputfile:
        matrix = [map(int, line.split()) for line in inputfile]
    column1 = [row[0] for row in matrix]
    row1 = matrix[0]
    if mean(column1) == 50:
        print('File "{}" has 1st row average =
{:.2f}'.format(filename, mean(row1)))

It's all a little easier if you use numpy:

import numpy as np

filenames = ['1.txt', '2.txt', '3.txt', '4.txt', '5.txt']

for filename in filenames:
    matrix = np.loadtxt(filename, dtype=int)
    column1 = matrix[:, 0]
    row1 = matrix[0, :]
    if sum(column1) == 50 * len(column1):
        print('File "{}" has 1st row average =
{:.2f}'.format(filename, np.mean(row1)))

Then again in practise I wouldn't be testing for equality of the mean.


Oscar


From rosuav at gmail.com  Thu May 23 07:35:50 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 21:35:50 +1000
Subject: file I/O and arithmetic calculation
In-Reply-To: <BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>
	<BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>
	<CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>
	<BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>
Message-ID: <CAPTjJmpemFfmLiE05DZ3ywGthx0=SP1EY8y7n_dwaCnpdjVR-w@mail.gmail.com>

On Thu, May 23, 2013 at 10:37 AM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> ----------------------------------------
>> From: oscar.j.benjamin at gmail.com
>> Date: Thu, 23 May 2013 01:34:37 +0100
>> Subject: Re: file I/O and arithmetic calculation
>> To: carlosnepomuceno at outlook.com
>> CC: python-list at python.org
>>
>> On 23 May 2013 00:49, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
>>>
>>> The code is pretty obvious to me, I mean there's no obfuscation at all.
>>
>> I honestly can't tell if you're joking.
>
> I'm not! lol

Reminds me of an episode of BBT where Sheldon's trying to figure out sarcasm.

Leonard: <obviously sarcastic comment>
Sheldon: "Was that sarcasm?"
Leonard: "Noooooo..."
Sheldon: "Was THAT sarcasm?"
Leonard: -- no answer needed.

Normally don't do this much list comprehension in an example. It may
be fine for the code, but it doesn't help explain stuff. :)

ChrisA


From wilkeira at gmail.com  Thu May 23 10:17:58 2013
From: wilkeira at gmail.com (Keira Wilson)
Date: Thu, 23 May 2013 07:17:58 -0700 (PDT)
Subject: file I/O and arithmetic calculation
In-Reply-To: <mailman.2011.1369308959.3114.python-list@python.org>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>
	<BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>
	<CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>
	<BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>
	<mailman.2011.1369308959.3114.python-list@python.org>
Message-ID: <427e93a6-0a85-4fe5-be76-ac11f199f2fa@googlegroups.com>

Dear all who involved with responding to my question - Thank you so much for your nice code which really helped me.


From denismfmcmahon at gmail.com  Thu May 23 16:12:43 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Thu, 23 May 2013 20:12:43 +0000 (UTC)
Subject: file I/O and arithmetic calculation
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>
	<BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>
	<CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>
	<BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>
	<mailman.2011.1369308959.3114.python-list@python.org>
	<427e93a6-0a85-4fe5-be76-ac11f199f2fa@googlegroups.com>
Message-ID: <knlt7r$qhr$1@dont-email.me>

On Thu, 23 May 2013 07:17:58 -0700, Keira Wilson wrote:

> Dear all who involved with responding to my question - Thank you so much
> for your nice code which really helped me.

Hold on a sec? Someone posted code that gave the correct answer to a 
homework question?

-- 
Denis McMahon, denismfmcmahon at gmail.com


From carlosnepomuceno at outlook.com  Thu May 23 18:22:32 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 24 May 2013 01:22:32 +0300
Subject: file I/O and arithmetic calculation
In-Reply-To: <knlt7r$qhr$1@dont-email.me>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>,
	<BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>,
	<CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>,
	<BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>,
	<CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>,
	<BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>,
	<mailman.2011.1369308959.3114.python-list@python.org>,
	<427e93a6-0a85-4fe5-be76-ac11f199f2fa@googlegroups.com>,
	<knlt7r$qhr$1@dont-email.me>
Message-ID: <BLU176-W36F3FD78BEF5319BB7DFEDD7AA0@phx.gbl>

----------------------------------------
> From: denismfmcmahon at gmail.com
[...]
>> Dear all who involved with responding to my question - Thank you so much
>> for your nice code which really helped me.
>
> Hold on a sec? Someone posted code that gave the correct answer to a
> homework question?
>
> --
> Denis McMahon, denismfmcmahon at gmail.com

Not sure what she've asked, but mine certainly do what I think she've asked. 		 	   		  

From wilkeira at gmail.com  Thu May 23 21:19:19 2013
From: wilkeira at gmail.com (Keira Wilson)
Date: Thu, 23 May 2013 18:19:19 -0700 (PDT)
Subject: file I/O and arithmetic calculation
In-Reply-To: <mailman.2040.1369347760.3114.python-list@python.org>
References: <CAK9meDsND9501=2ydmCAFi4s6+fw+rTrDGJA2qpEyXKoae6Axw@mail.gmail.com>,
	> <BLU176-W17E5DA2B650B3CE80F79BFD7A90@phx.gbl>,
	> <CAHVvXxR-5-s6GBY0nR_J--w=+T1SyeauCkEr_Frncj+trE=aWg@mail.gmail.com>,
	> <BLU176-W1629E4C46CA08C58AA583CD7A90@phx.gbl>,
	> <CAHVvXxRL=4+9+CkMKfZ3ei86i0xF14JZRpT2rB1RgmBV+ATtug@mail.gmail.com>,
	> <BLU176-W45829351ABC75D63C63DC9D7AA0@phx.gbl>,
	> <mailman.2011.1369308959.3114.python-list@python.org>, >
	<427e93a6-0a85-4fe5-be76-ac11f199f2fa@googlegroups.com>,
	> <knlt7r$qhr$1@dont-email.me>
	<mailman.2040.1369347760.3114.python-list@python.org>
Message-ID: <4a1151fb-c7cb-4ebf-8948-02797d1cc825@googlegroups.com>

not exactly for the homework, but as my starting point of learning
thank you so much.


From denismfmcmahon at gmail.com  Wed May 22 19:54:12 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Wed, 22 May 2013 23:54:12 +0000 (UTC)
Subject: file I/O and arithmetic calculation
References: <mailman.1970.1369239228.3114.python-list@python.org>
Message-ID: <knjlr4$v6m$6@dont-email.me>

On Thu, 23 May 2013 01:13:19 +0900, Keira Wilson wrote:

> I would appreciate if someone could write a simple python code for the
> purpose below:

Didn't have your data, so couldn't verify it completely, but try this:

import re
def v(s):
 l=len(s)
 t=0.
 for i in range(l):
  t=t+(abs(ord(s[i]))*1.)
 return t/(l*1.)
for n in range(5):
 m="c:/test/"+str(n+1)+".txt"
 f=open(m,"r")
 d=[]
 t=0.
 for l in range(10):
  d=d+[re.findall(r"[0-9.eE+-]+",f.readline())]
  t=t+v(d[l][0])
 f.close()
 c=t/10.
 if c==50.:
  t=0.
  for u in range(10):
   t=t+v(d[0][u])
  r=t/10.
  print "%s C1: %f R1: %f"%(m,c,r)

-- 
Denis McMahon, denismfmcmahon at gmail.com


From carlosnepomuceno at outlook.com  Wed May 22 20:02:09 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Thu, 23 May 2013 03:02:09 +0300
Subject: file I/O and arithmetic calculation
In-Reply-To: <knjlr4$v6m$6@dont-email.me>
References: <mailman.1970.1369239228.3114.python-list@python.org>,
	<knjlr4$v6m$6@dont-email.me>
Message-ID: <BLU176-W12BCA9CCAD1059EBB9837D7AA0@phx.gbl>

----------------------------------------
> From: denismfmcmahon at gmail.com
[...]
>
> import re
> def v(s):
> l=len(s)
> t=0.
> for i in range(l):
> t=t+(abs(ord(s[i]))*1.)
> return t/(l*1.)
> for n in range(5):
> m="c:/test/"+str(n+1)+".txt"
> f=open(m,"r")
> d=[]
> t=0.
> for l in range(10):
> d=d+[re.findall(r"[0-9.eE+-]+",f.readline())]
> t=t+v(d[l][0])
> f.close()
> c=t/10.
> if c==50.:
> t=0.
> for u in range(10):
> t=t+v(d[0][u])
> r=t/10.
> print "%s C1: %f R1: %f"%(m,c,r)
>
> --
> Denis McMahon, denismfmcmahon at gmail.com
> --
> http://mail.python.org/mailman/listinfo/python-list

Can you send it again without tabs? 		 	   		  

From drsalists at gmail.com  Wed May 22 23:31:30 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Wed, 22 May 2013 20:31:30 -0700
Subject: Ordered dictionaries compared
Message-ID: <CAGGBd_rQ=KEq=a957q6JTXKtenrjnZ+LmQKqRnX1+zTauyQV6A@mail.gmail.com>

What kind of ordered dictionaries?  Sorted by key.

I've redone the previous comparison, this time with a better red-black tree
implementation courtesy of Duncan G. Smith.

The comparison is at
http://stromberg.dnsalias.org/~strombrg/python-tree-and-heap-comparison/just-trees/

The Red-Black tree gave a much better showing this time, but it gave just
one 2nd place on one workload-interpreter - still kinda lackluster.  It
took 1st place 0 times.
-------------- next part --------------
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From solipsis at pitrou.net  Thu May 23 06:00:19 2013
From: solipsis at pitrou.net (Antoine Pitrou)
Date: Thu, 23 May 2013 10:00:19 +0000 (UTC)
Subject: Ordered dictionaries compared
References: <CAGGBd_rQ=KEq=a957q6JTXKtenrjnZ+LmQKqRnX1+zTauyQV6A@mail.gmail.com>
Message-ID: <loom.20130523T115915-15@post.gmane.org>

Dan Stromberg <drsalists <at> gmail.com> writes:
> 
> What kind of ordered dictionaries?? Sorted by key.

Calling them "sorted dictionaries" avoids any confusions with Python's
standard OrderedDict class:
http://docs.python.org/3.3/library/collections.html#ordereddict-objects

Regards

Antoine.




From buzzard at invalid.invalid  Thu May 23 12:41:32 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Thu, 23 May 2013 17:41:32 +0100
Subject: Ordered dictionaries compared
In-Reply-To: <mailman.1989.1369279892.3114.python-list@python.org>
References: <mailman.1989.1369279892.3114.python-list@python.org>
Message-ID: <519e46c0$0$26690$862e30e2@ngroups.net>

On 23/05/13 04:31, Dan Stromberg wrote:
>
> What kind of ordered dictionaries?  Sorted by key.
>
> I've redone the previous comparison, this time with a better red-black
> tree implementation courtesy of Duncan G. Smith.
>
> The comparison is at
> http://stromberg.dnsalias.org/~strombrg/python-tree-and-heap-comparison/just-trees/
>
> The Red-Black tree gave a much better showing this time, but it gave
> just one 2nd place on one workload-interpreter - still kinda
> lackluster.  It took 1st place 0 times.
>
>

A quick test of my Red Black Tree and Treap (Python 2.7).


 >>> def test_trees(data, randomize=True):
	cpy = data[:] # for deletion
	if randomize:
		random.shuffle(data)
		random.shuffle(cpy)
	t = binary_trees.RedBlackTree()
	start = time.time()
	for datum in data:
		t.insert(datum)
	print 'Red Black Tree insertion %s' % (time.time() - start)
	start = time.time()
	for datum in data:
		t.find(datum)
	print 'Red Black Tree find %s' % (time.time() - start)
	start = time.time()
	for datum in cpy:
		t.delete(datum)
	print 'Red Black Tree deletion %s' % (time.time() - start)
	t = binary_trees.Treap()
	start = time.time()
	for datum in data:
		t.insert(datum)
	print
	print 'Treap insertion %s' % (time.time() - start)
	start = time.time()
	for datum in data:
		t.find(datum)
	print 'Treap find %s' % (time.time() - start)
	start = time.time()
	for datum in cpy:
		t.delete(datum)
	print 'Treap deletion %s' % (time.time() - start)

	
 >>> test_trees(range(100000))
Red Black Tree insertion 5.42807197571
Red Black Tree find 1.58799219131
Red Black Tree deletion 3.87580800056

Treap insertion 6.79647684097
Treap find 2.11693120003
Treap deletion 4.61243915558
 >>>
 >>> test_trees(range(100000), False)
Red Black Tree insertion 6.29647898674
Red Black Tree find 1.157143116
Red Black Tree deletion 2.74785804749

Treap insertion 3.87288999557
Treap find 1.48776102066
Treap deletion 1.88962197304
 >>>


RBT is quicker than Treap for insertion with randomized data, but slower 
with ordered data. Randomized data will tend to minimize the number of 
tree rotations needed to keep the RBT balanced, whilst the Treap will be 
performing rotations to maintain the heap property in an already 
reasonably well balanced tree. With ordered data the RBT will have to 
work harder to keep the tree balanced, whilst the Treap will be able to 
maintain the heap property with fewer rotations.

No surprise that find() is generally quicker for RBTs, they tend to be 
better balanced.

Deletion is a bit more confusing. I suppose deletion from a better 
balanced tree will tend to be quicker, but deletion from a treap 
constructed from ordered data is (for some reason) quickest of all.

All these operations require a call to find(), and that is generally 
going to be quicker for RBTs. Treaps tend to require fewer subsequent 
rotations, but they have variable worth (in terms of rebalancing).

Looks like RBTs are better than treaps if they are being populated with 
randomly ordered data, but not if they are being populated with ordered 
data. RBTs are better for use cases that are heavy on finds.

Both types of tree appear to be better balanced (on the basis of the 
find results) if populated from ordered data. Treaps appear to perform 
better on insertion, find and deletion when populated from ordered data.

Duncan



From drsalists at gmail.com  Thu May 23 13:44:53 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Thu, 23 May 2013 10:44:53 -0700
Subject: Ordered dictionaries compared
In-Reply-To: <519e46c0$0$26690$862e30e2@ngroups.net>
References: <mailman.1989.1369279892.3114.python-list@python.org>
	<519e46c0$0$26690$862e30e2@ngroups.net>
Message-ID: <CAGGBd_q66CM0j3O74Y1LFa4t9gm5Mx1OYiTfQ-6803aBXSjFZA@mail.gmail.com>

On Thu, May 23, 2013 at 9:41 AM, duncan smith <buzzard at invalid.invalid>wrote:

>
> RBT is quicker than Treap for insertion with randomized data, but slower
> with ordered data. Randomized data will tend to minimize the number of tree
> rotations needed to keep the RBT balanced, whilst the Treap will be
> performing rotations to maintain the heap property in an already reasonably
> well balanced tree. With ordered data the RBT will have to work harder to
> keep the tree balanced, whilst the Treap will be able to maintain the heap
> property with fewer rotations.
>
> No surprise that find() is generally quicker for RBTs, they tend to be
> better balanced.
>
> Deletion is a bit more confusing. I suppose deletion from a better
> balanced tree will tend to be quicker, but deletion from a treap
> constructed from ordered data is (for some reason) quickest of all.
>
> All these operations require a call to find(), and that is generally going
> to be quicker for RBTs. Treaps tend to require fewer subsequent rotations,
> but they have variable worth (in terms of rebalancing).
>
> Looks like RBTs are better than treaps if they are being populated with
> randomly ordered data, but not if they are being populated with ordered
> data. RBTs are better for use cases that are heavy on finds.
>
> Both types of tree appear to be better balanced (on the basis of the find
> results) if populated from ordered data. Treaps appear to perform better on
> insertion, find and deletion when populated from ordered data.
>

Strange.  I was comparing randomized data (95% get, 50-50 get and set, 95%
set) when I found that treaps were quite a bit faster than red black trees.

The code I used is here:
http://stromberg.dnsalias.org/svn/python-tree-and-heap-comparison/trunk/

See also
https://en.wikipedia.org/wiki/Binary_search_tree#Performance_comparisons ,
which found that treaps were faster on average the red black trees.
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From buzzard at invalid.invalid  Thu May 23 19:57:51 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Fri, 24 May 2013 00:57:51 +0100
Subject: Ordered dictionaries compared
In-Reply-To: <mailman.2024.1369331102.3114.python-list@python.org>
References: <mailman.1989.1369279892.3114.python-list@python.org>
	<519e46c0$0$26690$862e30e2@ngroups.net>
	<mailman.2024.1369331102.3114.python-list@python.org>
Message-ID: <519ead02$0$60192$862e30e2@ngroups.net>

On 23/05/13 18:44, Dan Stromberg wrote:
>
> On Thu, May 23, 2013 at 9:41 AM, duncan smith <buzzard at invalid.invalid
> <mailto:buzzard at invalid.invalid>> wrote:
>
>
>     RBT is quicker than Treap for insertion with randomized data, but
>     slower with ordered data. Randomized data will tend to minimize the
>     number of tree rotations needed to keep the RBT balanced, whilst the
>     Treap will be performing rotations to maintain the heap property in
>     an already reasonably well balanced tree. With ordered data the RBT
>     will have to work harder to keep the tree balanced, whilst the Treap
>     will be able to maintain the heap property with fewer rotations.
>
>     No surprise that find() is generally quicker for RBTs, they tend to
>     be better balanced.
>
>     Deletion is a bit more confusing. I suppose deletion from a better
>     balanced tree will tend to be quicker, but deletion from a treap
>     constructed from ordered data is (for some reason) quickest of all.
>
>     All these operations require a call to find(), and that is generally
>     going to be quicker for RBTs. Treaps tend to require fewer
>     subsequent rotations, but they have variable worth (in terms of
>     rebalancing).
>
>     Looks like RBTs are better than treaps if they are being populated
>     with randomly ordered data, but not if they are being populated with
>     ordered data. RBTs are better for use cases that are heavy on finds.
>
>     Both types of tree appear to be better balanced (on the basis of the
>     find results) if populated from ordered data. Treaps appear to
>     perform better on insertion, find and deletion when populated from
>     ordered data.
>
> Strange.  I was comparing randomized data (95% get, 50-50 get and set,
> 95% set) when I found that treaps were quite a bit faster than red black
> trees.
>
> The code I used is here:
> http://stromberg.dnsalias.org/svn/python-tree-and-heap-comparison/trunk/
>
> See also
> https://en.wikipedia.org/wiki/Binary_search_tree#Performance_comparisons
> , which found that treaps were faster on average the red black trees.
>
>

Dan,
     Faster on average, but it depends what you're averaging over. As 
far as insertion and deletions are concerned my results agree with those 
in the paper, except they have treaps performing slightly faster than 
RBTs for insertion with randomly ordered data.

Deletion in your code is slightly different to that in mine. It might 
make a difference. Also, your code doesn't use sentinels (pros and 
cons). It could be down to implementation details.

Duncan


From alexander_naumov at opensuse.org  Thu May 23 03:20:15 2013
From: alexander_naumov at opensuse.org (Alex Naumov)
Date: Thu, 23 May 2013 09:20:15 +0200
Subject: newbie question about subprocess.Popen() arguments
Message-ID: <CABPy6+wGwvkyrq06k87hZfDO2-bNxsw72RNKyDq9hng_QwNPVw@mail.gmail.com>

Hello,

I'm trying to call new process with some parameters. The problem is that
the last parameter is a "string" that has a lot of spaces and different
symbols like slash and so on. I can save it in file and use name of this
file as parameter, but my question is: how to make it without   additional
saving?

import subprocess as sp

rc = sp.Popen(["prog", "--options", "<", msg], stdin=sp.PIPE,
stdout=sp.PIPE)
stdout = rc.communicate()[0]
print stdout



Thank you,
Alex

p.s.
type(msg) => <type 'str'>
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From __peter__ at web.de  Thu May 23 03:32:40 2013
From: __peter__ at web.de (Peter Otten)
Date: Thu, 23 May 2013 09:32:40 +0200
Subject: newbie question about subprocess.Popen() arguments
References: <CABPy6+wGwvkyrq06k87hZfDO2-bNxsw72RNKyDq9hng_QwNPVw@mail.gmail.com>
Message-ID: <knkglq$8mr$1@ger.gmane.org>

Alex Naumov wrote:

> I'm trying to call new process with some parameters. The problem is that
> the last parameter is a "string" that has a lot of spaces and different
> symbols like slash and so on. I can save it in file and use name of this
> file as parameter, but my question is: how to make it without   additional
> saving?
> 
> import subprocess as sp
> 
> rc = sp.Popen(["prog", "--options", "<", msg], stdin=sp.PIPE,
> stdout=sp.PIPE)
> stdout = rc.communicate()[0]
> print stdout

> p.s.
> type(msg) => <type 'str'>

The < operator is a shell feature, not an argument, and msg is intended to 
be send to prog's stdin. The communicate() method accepts a parameter for 
that. So:

rc = sp.Popen(["prog", "--options"], stdin=sp.PIPE, stdout=sp.PIPE)
stdout = rc.communicate(msg)[0]



From alexander_naumov at opensuse.org  Thu May 23 03:40:48 2013
From: alexander_naumov at opensuse.org (Alex Naumov)
Date: Thu, 23 May 2013 09:40:48 +0200
Subject: newbie question about subprocess.Popen() arguments
In-Reply-To: <knkglq$8mr$1@ger.gmane.org>
References: <CABPy6+wGwvkyrq06k87hZfDO2-bNxsw72RNKyDq9hng_QwNPVw@mail.gmail.com>
	<knkglq$8mr$1@ger.gmane.org>
Message-ID: <CABPy6+yb+Qu0Uut7+8wfqKsOX9xBt4kAM7vr--2GPgnF9KZ8tQ@mail.gmail.com>

Thank you very much, Peter!
It works!


On Thu, May 23, 2013 at 9:32 AM, Peter Otten <__peter__ at web.de> wrote:

> Alex Naumov wrote:
>
> > I'm trying to call new process with some parameters. The problem is that
> > the last parameter is a "string" that has a lot of spaces and different
> > symbols like slash and so on. I can save it in file and use name of this
> > file as parameter, but my question is: how to make it without
> additional
> > saving?
> >
> > import subprocess as sp
> >
> > rc = sp.Popen(["prog", "--options", "<", msg], stdin=sp.PIPE,
> > stdout=sp.PIPE)
> > stdout = rc.communicate()[0]
> > print stdout
>
> > p.s.
> > type(msg) => <type 'str'>
>
> The < operator is a shell feature, not an argument, and msg is intended to
> be send to prog's stdin. The communicate() method accepts a parameter for
> that. So:
>
> rc = sp.Popen(["prog", "--options"], stdin=sp.PIPE, stdout=sp.PIPE)
> stdout = rc.communicate(msg)[0]
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From lokeshkoppaka at gmail.com  Thu May 23 05:51:36 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Thu, 23 May 2013 02:51:36 -0700 (PDT)
Subject: Scope of a class..help???
Message-ID: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>

i had written the following code i am unable to create the instance of the class "Node" in the method "number_to_LinkedList" can any one help me how to do ??
and what is the error??
  

class Node:
    def __init__(self, value=None):
        self.value = value
        self.next = None



def number_to_LinkedList(numbers):
      pass
      list_numbers = list(numbers)
      head_node = Node() #unable to create the instance saying UnboundedLocal
      head_node.value = list_numbers[0]
      head_node.next = None
      current_node = head_node
      for i in range(1,len(list_numbers)):
        new_node = Node()
        new_node.value = list_numbers[i]
        new_node.next = current_node
        current_node = new_node
      current_node.next = None
      while Node:
        print Node.data
        Node = Node.next


From rosuav at gmail.com  Thu May 23 06:00:27 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 20:00:27 +1000
Subject: Scope of a class..help???
In-Reply-To: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
References: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
Message-ID: <CAPTjJmq4ff5Vs2_YmNMKhH65BrfOAkcCN9KuNHW8GNNh=8upCA@mail.gmail.com>

On Thu, May 23, 2013 at 7:51 PM,  <lokeshkoppaka at gmail.com> wrote:
> i had written the following code i am unable to create the instance of the class "Node" in the method "number_to_LinkedList" can any one help me how to do ??
> and what is the error??

It would really help if you post the actual exception and traceback.
It's UnboundLocal, not Unbounded... and here's the problem:

> def number_to_LinkedList(numbers):
>       head_node = Node() #unable to create the instance saying UnboundedLocal
>       while Node:
>         print Node.data
>         Node = Node.next

You're assigning to Node. I think you mean to have some other local
variable here, for the iteration at the end. Since you assign to the
name Node inside the function (and don't have a global declaration),
the name Node is local to the function. Python doesn't let you
reference the global "prior to" shadowing it with the local, so you
get this error.

ChrisA


From __peter__ at web.de  Thu May 23 06:18:16 2013
From: __peter__ at web.de (Peter Otten)
Date: Thu, 23 May 2013 12:18:16 +0200
Subject: Scope of a class..help???
References: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
Message-ID: <knkqca$fd4$1@ger.gmane.org>

lokeshkoppaka at gmail.com wrote:

> i had written the following code i am unable to create the instance of the
> class "Node" in the method "number_to_LinkedList" can any one help me how
> to do ?? and what is the error??
>   
> 
> class Node:
>     def __init__(self, value=None):
>         self.value = value
>         self.next = None
> 
> 
> 
> def number_to_LinkedList(numbers):
>       pass
>       list_numbers = list(numbers)
>       head_node = Node() #unable to create the instance saying
>       UnboundedLocal head_node.value = list_numbers[0]
>       head_node.next = None
>       current_node = head_node
>       for i in range(1,len(list_numbers)):
>         new_node = Node()
>         new_node.value = list_numbers[i]
>         new_node.next = current_node
>         current_node = new_node
>       current_node.next = None
>       while Node:
>         print Node.data
>         Node = Node.next

You have to decide if you want to use a name in a function locally or to 
access a global. Python treats names that are being assigned to anywhere in 
a function as local throughout the whole function.

x = "global"
def f():
    print x # ok, access global variable

x = "global"
def g():
    x = "local"
    print x # ok, accessing local variable

x = "global"
def h():
    print x # error, accessing local variable that has not 
            # been assigned a value
    x = "local"





From lokeshkoppaka at gmail.com  Thu May 23 06:23:26 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Thu, 23 May 2013 03:23:26 -0700 (PDT)
Subject: Scope of a class..help???
In-Reply-To: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
References: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
Message-ID: <110b4762-392d-4430-b1aa-6e8168ced9f3@googlegroups.com>

 Thanks Chris Angelico,
i am new to python can you suggest me how to remove the error and solve it.
so,how can i create an instance for "Node" in that function??,is, it not possible to create an instance in such a way?



From rosuav at gmail.com  Thu May 23 06:27:27 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 20:27:27 +1000
Subject: Scope of a class..help???
In-Reply-To: <110b4762-392d-4430-b1aa-6e8168ced9f3@googlegroups.com>
References: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
	<110b4762-392d-4430-b1aa-6e8168ced9f3@googlegroups.com>
Message-ID: <CAPTjJmrL4wYKdFmsAwmOJTVjcMSUA5hMh_uKxQy3rrzxJJaxZQ@mail.gmail.com>

On Thu, May 23, 2013 at 8:23 PM,  <lokeshkoppaka at gmail.com> wrote:
>  Thanks Chris Angelico,
> i am new to python can you suggest me how to remove the error and solve it.
> so,how can i create an instance for "Node" in that function??,is, it not possible to create an instance in such a way?

The problem isn't the instantiation; the problem's further down, where
you reuse the name "Node" to iterate over your list. Rename that to
something else and you should be right.

ChrisA


From lokeshkoppaka at gmail.com  Thu May 23 06:25:57 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Thu, 23 May 2013 03:25:57 -0700 (PDT)
Subject: Scope of a class..help???
In-Reply-To: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
References: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
Message-ID: <6f05ea64-4a3a-4f92-a4c9-ade8bf7117c6@googlegroups.com>

ok Peter Otten,
but how to make a Class global??



From rosuav at gmail.com  Thu May 23 07:40:14 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 21:40:14 +1000
Subject: Scope of a class..help???
In-Reply-To: <6f05ea64-4a3a-4f92-a4c9-ade8bf7117c6@googlegroups.com>
References: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
	<6f05ea64-4a3a-4f92-a4c9-ade8bf7117c6@googlegroups.com>
Message-ID: <CAPTjJmpaFQb_=1s9vDfetjPasSsxuKTxz0aW6XpgUYp=y-L3JA@mail.gmail.com>

On Thu, May 23, 2013 at 8:25 PM,  <lokeshkoppaka at gmail.com> wrote:
> ok Peter Otten,
> but how to make a Class global??

He gave some examples. It'd be helpful to quote some of his post, for
context... and preferably, show some proof that you've understood it.

You're starting a number of threads that look like you're trying to
get us to do your homework. You need to demonstrate that you actually
understand the material you're supposed to be learning.

ChrisA


From timr at probo.com  Fri May 24 01:05:57 2013
From: timr at probo.com (Tim Roberts)
Date: Thu, 23 May 2013 22:05:57 -0700
Subject: Scope of a class..help???
References: <913d7fc1-4608-4ff5-8b51-2ae2cd67781a@googlegroups.com>
	<6f05ea64-4a3a-4f92-a4c9-ade8bf7117c6@googlegroups.com>
Message-ID: <oqstp81dmciehdkedt7b7i4bnlug2l1jg1@4ax.com>

lokeshkoppaka at gmail.com wrote:
>
>ok Peter Otten,
>but how to make a Class global??

Your class IS global.  I still don't think you understand what you did
wrong.  You've tripped into a strange little quirk of scoping.  Here is
your code with some unimportant lines removes.

class Node:
    def __init__(self, value=None):
        self.value = value
        self.next = None

## OK, at this point, you have a global called "Node", which is a class.

def number_to_LinkedList(numbers):
      pass
      list_numbers = list(numbers)
      head_node = Node()
      # ... 
      current_node.next = None
      while Node:
        print Node.data

Python actually does a first scan through your function before it starts to
compile it.  When it does the scan, it sees you use the name "Node" as a
local variable.  At that point, it remembers that "in this function scope,
'Node' is a local name".  Now, it codes to compile the class.  When it
encounters Node() for the first time, it sees that "Node" is not defined
locally, even though it was supposed to be a local name.

You are assuming that the first Node() in that function will automatically
refer to the global class.  It won't.  The only way to solve this dilemma
is to change the name you use in the "while" loop.
-- 
Tim Roberts, timr at probo.com
Providenza & Boekelheide, Inc.


From lokeshkoppaka at gmail.com  Thu May 23 05:54:02 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Thu, 23 May 2013 02:54:02 -0700 (PDT)
Subject: 2's Complement in python help.
Message-ID: <53dc6273-5aed-44e9-8f39-7eb7f4f3a1b1@googlegroups.com>

Can anyone give me an idea of how to find the 2's Complement in python with an example


From rosuav at gmail.com  Thu May 23 06:03:43 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 20:03:43 +1000
Subject: 2's Complement in python help.
In-Reply-To: <53dc6273-5aed-44e9-8f39-7eb7f4f3a1b1@googlegroups.com>
References: <53dc6273-5aed-44e9-8f39-7eb7f4f3a1b1@googlegroups.com>
Message-ID: <CAPTjJmp2WcXX9RQayL2efRwzNS8Lx0UWeL1tm6q-g0CE0TRVBA@mail.gmail.com>

On Thu, May 23, 2013 at 7:54 PM,  <lokeshkoppaka at gmail.com> wrote:
> Can anyone give me an idea of how to find the 2's Complement in python with an example

Do you know what two's complement is? (Not to be confused with two's
compliment, which is when numbers start telling you how clever you
are.) If not, you should probably look it up on Wikipedia or
something. Once you know what the term means, you can start
implementing in Python.

ChrisA


From js at globe.de  Thu May 23 06:37:05 2013
From: js at globe.de (Schneider)
Date: Thu, 23 May 2013 12:37:05 +0200
Subject: serialize a class to XML and back
Message-ID: <519DF151.1080405@globe.de>

Hi list,

how can I serialize a python class to XML? Plus a way to get the class 
back from the XML?

My aim is to store instances of this class in a database.

bg,
Johannes

-- 
GLOBE Development GmbH
K?nigsberger Strasse 260
48157 M?nsterGLOBE Development GmbH
K?nigsberger Strasse 260
48157 M?nster
0251/5205 390



From burak.arslan at arskom.com.tr  Thu May 23 07:16:34 2013
From: burak.arslan at arskom.com.tr (Burak Arslan)
Date: Thu, 23 May 2013 14:16:34 +0300
Subject: serialize a class to XML and back
In-Reply-To: <519DF151.1080405@globe.de>
References: <519DF151.1080405@globe.de>
Message-ID: <519DFA92.5050205@arskom.com.tr>

On 05/23/13 13:37, Schneider wrote:
> Hi list,
>
> how can I serialize a python class to XML? Plus a way to get the class 
> back from the XML?
>
> My aim is to store instances of this class in a database.

Hi,

I'm working on a project called Spyne (http://spyne.io). With one object 
definition, you can serialize to/from xml and save to database via 
SQLAlchemy.

The code generator on the site has examples for RPC and SQL. If you're 
not interested in doing RPC with the resulting document, here's an 
example for just the xml part: 
https://github.com/arskom/spyne/blob/master/examples/xml_utils.py

Best regards,
Burak



From wuwei23 at gmail.com  Thu May 23 20:01:01 2013
From: wuwei23 at gmail.com (alex23)
Date: Thu, 23 May 2013 17:01:01 -0700 (PDT)
Subject: serialize a class to XML and back
References: <mailman.2009.1369305490.3114.python-list@python.org>
Message-ID: <31e0af40-d1e5-4b09-b0c2-f4a87b4399e2@wg15g2000pbb.googlegroups.com>

On May 23, 8:37?pm, Schneider <j... at globe.de> wrote:
> My aim is to store instances of this class in a database.

Have you considered just pickling the classes instead?



From dieter at handshake.de  Sat May 25 01:54:54 2013
From: dieter at handshake.de (dieter)
Date: Sat, 25 May 2013 07:54:54 +0200
Subject: serialize a class to XML and back
References: <519DF151.1080405@globe.de>
Message-ID: <87zjvjppsh.fsf@handshake.de>

Schneider <js at globe.de> writes:

> how can I serialize a python class to XML? Plus a way to get the class
> back from the XML?
>
> My aim is to store instances of this class in a database.

In case you want to describe the XML data via an XML-schema
(e.g. to exchange it with other applications; maybe via
WebServices), you may have a look at "PyXB".


The approach of "PyXB" may be a bit different from yours:

  It starts with an XML-schema description and from
  it generates Python classes corresponding to the types
  mentioned in the schema.

  Instances of those classes can then be easily serialized
  to XML and XML documents corresponding to types defined
  in the schema can easily be converted into corresponding
  class instances.

  It is not too difficult to customize the classes
  used for a given type - e.g. to give them special methods
  related to your application.


You may want to start with your (arbitrary) Python classes
and get their instances serialized into an adequate XML document.

This will not work in all cases: some things are very difficult
to serialize (maybe even not serializable at all - e.g. locks).

If you plan to use anything already existing, then almost
surely, this will impose restrictions of your classes.



From js at globe.de  Fri May 31 07:16:21 2013
From: js at globe.de (Schneider)
Date: Fri, 31 May 2013 13:16:21 +0200
Subject: serialize a class to XML and back
In-Reply-To: <87zjvjppsh.fsf@handshake.de>
References: <519DF151.1080405@globe.de> <87zjvjppsh.fsf@handshake.de>
Message-ID: <51A88685.70409@globe.de>

On 25.05.2013 07:54, dieter wrote:
> Schneider <js at globe.de> writes:
>
>> how can I serialize a python class to XML? Plus a way to get the class
>> back from the XML?
>>
>> My aim is to store instances of this class in a database.
> In case you want to describe the XML data via an XML-schema
> (e.g. to exchange it with other applications; maybe via
> WebServices), you may have a look at "PyXB".
>
>
> The approach of "PyXB" may be a bit different from yours:
>
>    It starts with an XML-schema description and from
>    it generates Python classes corresponding to the types
>    mentioned in the schema.
>
>    Instances of those classes can then be easily serialized
>    to XML and XML documents corresponding to types defined
>    in the schema can easily be converted into corresponding
>    class instances.
>
>    It is not too difficult to customize the classes
>    used for a given type - e.g. to give them special methods
>    related to your application.
>
>
> You may want to start with your (arbitrary) Python classes
> and get their instances serialized into an adequate XML document.
>
> This will not work in all cases: some things are very difficult
> to serialize (maybe even not serializable at all - e.g. locks).

I have just small classes containing text (strings)  numbers (as ids) 
and references to other classes of this type.

>
> If you plan to use anything already existing, then almost
> surely, this will impose restrictions of your classes.
>


-- 
GLOBE Development GmbH
K?nigsberger Strasse 260
48157 M?nsterGLOBE Development GmbH
K?nigsberger Strasse 260
48157 M?nster
0251/5205 390



From clp2 at rebertia.com  Sun May 26 16:36:53 2013
From: clp2 at rebertia.com (Chris Rebert)
Date: Sun, 26 May 2013 13:36:53 -0700
Subject: serialize a class to XML and back
In-Reply-To: <519DF151.1080405@globe.de>
References: <519DF151.1080405@globe.de>
Message-ID: <CAMZYqRQVNf7D6QOS0-ZmMCZd2A9Z3PT50r7UK9tVyviTEbuzRw@mail.gmail.com>

On May 23, 2013 3:42 AM, "Schneider" <js at globe.de> wrote:
>
> Hi list,
>
> how can I serialize a python class to XML? Plus a way to get the class
back from the XML?

There's pyxser: http://pythonhosted.org/pyxser/

> My aim is to store instances of this class in a database.

Honestly, I would avoid XML if you can. Consider using JSON (Python
includes the `json` module in the std lib) or pickle instead. Compared to
XML: The former is more standardized (in the context of serializing
objects) and less verbose; the latter is more efficient (if you don't care
about cross-language accessibility); both have more convenient APIs.

Cheers,
Chris
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From roy at panix.com  Sun May 26 16:48:21 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 26 May 2013 16:48:21 -0400
Subject: serialize a class to XML and back
References: <519DF151.1080405@globe.de>
	<mailman.2197.1369600623.3114.python-list@python.org>
Message-ID: <roy-D5172C.16482026052013@news.panix.com>

In article <mailman.2197.1369600623.3114.python-list at python.org>,
 Chris Rebert <clp2 at rebertia.com> wrote:

> On May 23, 2013 3:42 AM, "Schneider" <js at globe.de> wrote:
> >
> > Hi list,
> >
> > how can I serialize a python class to XML? Plus a way to get the class
> back from the XML?
> 
> There's pyxser: http://pythonhosted.org/pyxser/
> 
> > My aim is to store instances of this class in a database.
> 
> Honestly, I would avoid XML if you can. Consider using JSON (Python
> includes the `json` module in the std lib) or pickle instead. Compared to
> XML: The former is more standardized (in the context of serializing
> objects) and less verbose; the latter is more efficient (if you don't care
> about cross-language accessibility); both have more convenient APIs.

Some other points...

If you care about efficiency and want to use json, don't use the one 
that comes packaged with the standard library.  There are lots of 
third-party json packages (ujson is the one we use) which are 
significantly faster.  Not sure if that's true of the newest python 
releases, but it was certainly true in 2.6.

The advantage of pickle over json is that pickle can serialize many 
types of objects that json can't.  The other side of the coin is that 
pickle is python-specific, so if you think you'll ever need to read your 
data from other languages, pickle is right out.


From irmen.NOSPAM at xs4all.nl  Sun May 26 18:40:01 2013
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Mon, 27 May 2013 00:40:01 +0200
Subject: serialize a class to XML and back
In-Reply-To: <roy-D5172C.16482026052013@news.panix.com>
References: <519DF151.1080405@globe.de>
	<mailman.2197.1369600623.3114.python-list@python.org>
	<roy-D5172C.16482026052013@news.panix.com>
Message-ID: <51a28f42$0$15870$e4fe514c@news.xs4all.nl>

On 26-5-2013 22:48, Roy Smith wrote:

> The advantage of pickle over json is that pickle can serialize many 
> types of objects that json can't.  The other side of the coin is that 
> pickle is python-specific, so if you think you'll ever need to read your 
> data from other languages, pickle is right out.

That is not entirely true :)  I've written a pickle implementation for Java and .NET
that is almost feature complete; it is part of http://pythonhosted.org/Pyro4/pyrolite.html

Still, pickle may not be the best choice here.

Cheers
Irmen



From roy at panix.com  Sun May 26 20:39:01 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 26 May 2013 20:39:01 -0400
Subject: serialize a class to XML and back
References: <519DF151.1080405@globe.de>
	<mailman.2197.1369600623.3114.python-list@python.org>
	<roy-D5172C.16482026052013@news.panix.com>
	<51a28f42$0$15870$e4fe514c@news.xs4all.nl>
Message-ID: <roy-2C62C9.20390126052013@news.panix.com>

In article <51a28f42$0$15870$e4fe514c at news.xs4all.nl>,
 Irmen de Jong <irmen.NOSPAM at xs4all.nl> wrote:

> On 26-5-2013 22:48, Roy Smith wrote:
> 
> > The advantage of pickle over json is that pickle can serialize many 
> > types of objects that json can't.  The other side of the coin is that 
> > pickle is python-specific, so if you think you'll ever need to read your 
> > data from other languages, pickle is right out.
> 
> That is not entirely true :)  I've written a pickle implementation for Java 
> and .NET
> that is almost feature complete; it is part of 
> http://pythonhosted.org/Pyro4/pyrolite.html

Very cool

> Still, pickle may not be the best choice here.

Perhaps not, but lots of points for the awesomeness factor.


From irmen.NOSPAM at xs4all.nl  Mon May 27 14:45:07 2013
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Mon, 27 May 2013 20:45:07 +0200
Subject: serialize a class to XML and back
In-Reply-To: <roy-2C62C9.20390126052013@news.panix.com>
References: <519DF151.1080405@globe.de>
	<mailman.2197.1369600623.3114.python-list@python.org>
	<roy-D5172C.16482026052013@news.panix.com>
	<51a28f42$0$15870$e4fe514c@news.xs4all.nl>
	<roy-2C62C9.20390126052013@news.panix.com>
Message-ID: <51a3a9b5$0$15963$e4fe514c@news.xs4all.nl>

On 27-5-2013 2:39, Roy Smith wrote:
> In article <51a28f42$0$15870$e4fe514c at news.xs4all.nl>,
>  Irmen de Jong <irmen.NOSPAM at xs4all.nl> wrote:
> 
>> On 26-5-2013 22:48, Roy Smith wrote:
>>
>>> The advantage of pickle over json is that pickle can serialize many 
>>> types of objects that json can't.  The other side of the coin is that 
>>> pickle is python-specific, so if you think you'll ever need to read your 
>>> data from other languages, pickle is right out.
>>
>> That is not entirely true :)  I've written a pickle implementation for Java 
>> and .NET
>> that is almost feature complete; it is part of 
>> http://pythonhosted.org/Pyro4/pyrolite.html
> 
> Very cool
> 
>> Still, pickle may not be the best choice here.
> 
> Perhaps not, but lots of points for the awesomeness factor.
> 

Thanks for the praise :)

There's another interesting thing perhaps to also mention about Pyrolite. Its Pickle
implementation obviously maps built in types to their counterparts in Java/.NET, but it
is also capable of unpickling custom classes. It defaults to outputting a simple
hashtable with the class's properties in it, but you can also provide a custom
deserializer to recreate a custom object (it already does this automatically for a few
complex types such as DateTime, BigDecimal, and a bunch of Pyro specific types).

As the unpicklers are not executing any Java or .NET code dynamically they are not
susceptible to the security issue that Python's pickle has. Still: tread with care.
(Especially if you use the lib to pickle stuff and unpickle it on the Python side).

Also, the one missing feature is memo-ing when pickling so that you can pickle recursive
object graphs. It now throws a stack overflow exception instead.


Irmen




From js at globe.de  Fri May 31 07:21:39 2013
From: js at globe.de (Schneider)
Date: Fri, 31 May 2013 13:21:39 +0200
Subject: serialize a class to XML and back
In-Reply-To: <roy-D5172C.16482026052013@news.panix.com>
References: <519DF151.1080405@globe.de>
	<mailman.2197.1369600623.3114.python-list@python.org>
	<roy-D5172C.16482026052013@news.panix.com>
Message-ID: <51A887C3.6010702@globe.de>

On 26.05.2013 22:48, Roy Smith wrote:
> In article <mailman.2197.1369600623.3114.python-list at python.org>,
>   Chris Rebert <clp2 at rebertia.com> wrote:
>
>> On May 23, 2013 3:42 AM, "Schneider" <js at globe.de> wrote:
>>> Hi list,
>>>
>>> how can I serialize a python class to XML? Plus a way to get the class
>> back from the XML?
>>
>> There's pyxser: http://pythonhosted.org/pyxser/
>>
>>> My aim is to store instances of this class in a database.
>> Honestly, I would avoid XML if you can. Consider using JSON (Python
>> includes the `json` module in the std lib) or pickle instead. Compared to
>> XML: The former is more standardized (in the context of serializing
>> objects) and less verbose; the latter is more efficient (if you don't care
>> about cross-language accessibility); both have more convenient APIs.
> Some other points...
>
> If you care about efficiency and want to use json, don't use the one
> that comes packaged with the standard library.  There are lots of
> third-party json packages (ujson is the one we use) which are
> significantly faster.  Not sure if that's true of the newest python
> releases, but it was certainly true in 2.6.

I think performance can be a problem in future. This question is part of 
a multi-user rss-reader solution, which I'm going to develop.

I want to store the feed entries (+ some additional data) as XML in a 
database.

> The advantage of pickle over json is that pickle can serialize many
> types of objects that json can't.  The other side of the coin is that
> pickle is python-specific, so if you think you'll ever need to read your
> data from other languages, pickle is right out.


-- 
GLOBE Development GmbH
K?nigsberger Strasse 260
48157 M?nsterGLOBE Development GmbH
K?nigsberger Strasse 260
48157 M?nster
0251/5205 390



From lokeshkoppaka at gmail.com  Thu May 23 07:30:15 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Thu, 23 May 2013 04:30:15 -0700 (PDT)
Subject: help in obtaining binary equivalent of a decimal number in python
Message-ID: <7f794f03-03c9-44de-8312-4ad33b68c266@googlegroups.com>

i need to get 32 bit binary equivalent of a decimal and need to change the 0's to 1's and 1's to 0's
For Example
if the input is 2 
Output should be:
the 32bit equivalent of 2 :0000 0000 0000 0000 0000 0000 0000 0010
and the 1's compliment is:1111 1111 1111 1111 1111 1111 1111 1101



is there any pre-defined function to get the above results in python?? 


From rosuav at gmail.com  Thu May 23 07:37:30 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 23 May 2013 21:37:30 +1000
Subject: help in obtaining binary equivalent of a decimal number in python
In-Reply-To: <7f794f03-03c9-44de-8312-4ad33b68c266@googlegroups.com>
References: <7f794f03-03c9-44de-8312-4ad33b68c266@googlegroups.com>
Message-ID: <CAPTjJmoFCvjGLN4kB-VL0SmRQDi90_j64ZV1efzKyc9pp8p0tg@mail.gmail.com>

On Thu, May 23, 2013 at 9:30 PM,  <lokeshkoppaka at gmail.com> wrote:
> i need to get 32 bit binary equivalent of a decimal and need to change the 0's to 1's and 1's to 0's
> For Example
> if the input is 2
> Output should be:
> the 32bit equivalent of 2 :0000 0000 0000 0000 0000 0000 0000 0010
> and the 1's compliment is:1111 1111 1111 1111 1111 1111 1111 1101
>
>
>
> is there any pre-defined function to get the above results in python??

You're asking for bitwise negation. Now that you know the keyword(s)
to look for, you should be able to figure out the rest with a few
quick docs and/or web searches.

ChrisA


From davea at davea.name  Thu May 23 07:55:36 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 23 May 2013 07:55:36 -0400
Subject: help in obtaining binary equivalent of a decimal number in python
In-Reply-To: <7f794f03-03c9-44de-8312-4ad33b68c266@googlegroups.com>
References: <7f794f03-03c9-44de-8312-4ad33b68c266@googlegroups.com>
Message-ID: <519E03B8.7020907@davea.name>

On 05/23/2013 07:30 AM, lokeshkoppaka at gmail.com wrote:
> i need to get 32 bit binary equivalent of a decimal and need to change the 0's to 1's and 1's to 0's
> For Example
> if the input is 2
> Output should be:
> the 32bit equivalent of 2 :0000 0000 0000 0000 0000 0000 0000 0010
> and the 1's compliment is:1111 1111 1111 1111 1111 1111 1111 1101
>
>
>
> is there any pre-defined function to get the above results in python??
>

I'm curious as to the intent of the assignment. Are you supposed to be 
learning about base conversion, about ones and twos complement, or about 
Python?

Assuming the intent is to learn about Python, the built-in function 
bin() will take a Python integer (which is not decimal) and convert it 
to a str.  At that point, you can manipulate the string any way you like.

x = 45
print bin(45)
0b101101


Perhaps you want to start by stripping off the leading '0b' using a 
slice.  Then you want to pad it to 32 columns by prepending some number 
of zeroes.  Then you want to insert some spaces at regular intervals.

Presumably doing the ones-complement operation on that string is then 
pretty easy for you.

-- 
DaveA


From roy at panix.com  Thu May 23 09:09:21 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 23 May 2013 09:09:21 -0400
Subject: Debugging parallel nose tests?
Message-ID: <roy-1CC2EA.09092123052013@news.panix.com>

I've got a suite of about 150 tests written using unittest.  It takes 
5-10 minutes to run, so I'd really like to use nose to run things in 
parallel.  The problem is, when I do that, I get lots of test failures.  
Obviously, we've got some kind of inter-test dependency that I haven't 
been able to locate.

Is there some way to make nose print a report of how it partitioned the 
tests across the various processes?  If I could see that, it might help 
us reproduce the failures.

We're using:

nosetests --process-timeout=60 --processes=40 test_api.py

and

_multiprocess_can_split_ = True


From davea at davea.name  Thu May 23 14:31:36 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 23 May 2013 14:31:36 -0400
Subject: Debugging parallel nose tests?
In-Reply-To: <roy-1CC2EA.09092123052013@news.panix.com>
References: <roy-1CC2EA.09092123052013@news.panix.com>
Message-ID: <519E6088.5070002@davea.name>

On 05/23/2013 09:09 AM, Roy Smith wrote:
>
>      <SNIP>
>
> nosetests --process-timeout=60 --processes=40 test_api.py
>

Do you have a 40-processor system?  And do you have enough RAM to run 
all of those processes?


-- 
DaveA


From roy at panix.com  Thu May 23 21:44:07 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 23 May 2013 21:44:07 -0400
Subject: Debugging parallel nose tests?
References: <roy-1CC2EA.09092123052013@news.panix.com>
	<mailman.2027.1369333910.3114.python-list@python.org>
Message-ID: <roy-32397F.21440723052013@news.panix.com>

In article <mailman.2027.1369333910.3114.python-list at python.org>,
 Dave Angel <davea at davea.name> wrote:

> On 05/23/2013 09:09 AM, Roy Smith wrote:
> >
> >      <SNIP>
> >
> > nosetests --process-timeout=60 --processes=40 test_api.py
> >
> 
> Do you have a 40-processor system?

No, but many of the tests are I/O bound.

> And do you have enough RAM to run all of those processes?

Yes.  The box I'm on now has 8 gig.  I'd doing a 40 process run right 
now, and I've still got 1/2 gig free.


From jeanmichel at sequans.com  Fri May 24 05:33:40 2013
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Fri, 24 May 2013 09:33:40 -0000
Subject: Debugging parallel nose tests?
In-Reply-To: <roy-32397F.21440723052013@news.panix.com>
Message-ID: <1442952133.19384735.1369386305536.JavaMail.root@sequans.com>

----- Original Message -----
> In article <mailman.2027.1369333910.3114.python-list at python.org>,
>  Dave Angel <davea at davea.name> wrote:
> 
> > On 05/23/2013 09:09 AM, Roy Smith wrote:
> > >
> > >      <SNIP>
> > >
> > > nosetests --process-timeout=60 --processes=40 test_api.py
> > >
> > 
> > Do you have a 40-processor system?
> 
> No, but many of the tests are I/O bound.

Sorry to hijack your thread but what do you mean by that ? 
I have a lot of tests myself that spend most of their time writing and reading files. Should I try to multiprocess  them ?

JM


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From roy at panix.com  Fri May 24 07:47:45 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 24 May 2013 07:47:45 -0400
Subject: Debugging parallel nose tests?
In-Reply-To: <1442952133.19384735.1369386305536.JavaMail.root@sequans.com>
References: <1442952133.19384735.1369386305536.JavaMail.root@sequans.com>
Message-ID: <11040677-5704-4CEC-9F0C-4B24CBD611A6@panix.com>


On May 24, 2013, at 5:05 AM, Jean-Michel Pichavant wrote:

> ----- Original Message -----
>> In article <mailman.2027.1369333910.3114.python-list at python.org>,
>> Dave Angel <davea at davea.name> wrote:
>> 
>>> On 05/23/2013 09:09 AM, Roy Smith wrote:
>>>> 
>>>>     <SNIP>
>>>> 
>>>> nosetests --process-timeout=60 --processes=40 test_api.py
>>>> 
>>> 
>>> Do you have a 40-processor system?
>> 
>> No, but many of the tests are I/O bound.
> 
> Sorry to hijack your thread but what do you mean by that ? 

That means that a lot of time running the test is spent waiting for I/O (in this case, network reads), as opposed to actually running on a CPU.

> I have a lot of tests myself that spend most of their time writing and reading files. Should I try to multiprocess  them ?

Maybe :-)

--
Roy Smith
roy at panix.com



From roy at panix.com  Fri May 24 23:09:18 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 24 May 2013 23:09:18 -0400
Subject: Debugging parallel nose tests?
References: <roy-1CC2EA.09092123052013@news.panix.com>
Message-ID: <roy-9BA181.23091824052013@news.panix.com>

In article <roy-1CC2EA.09092123052013 at news.panix.com>,
 Roy Smith <roy at panix.com> wrote:

> Is there some way to make nose print a report of how it partitioned the 
> tests across the various processes?

I never found such a feature, but I did figure out a way to do what I 
needed.  We use a system of unique id's to track HTTP requests through 
our system.  All you need do is add a X-Unique-Request-ID header and any 
of our server processes will log that.  So, I just had my test suite add:

X-Unique-Request-ID: name-of-test.process-id

to each HTTP request.  That got me what I was looking for (to know what 
tests were grouped into the same process).

> We're using:
> 
> nosetests --process-timeout=60 --processes=40 test_api.py

It turned out, the answer was purely a timing issue.  We had some tests 
that called out to facebook.  Those were (intermittently) so slow they 
caused the 60 second timeout to be exceeded.  The solution there was to 
pull the facebook tests out to their own suite (which we'll run in 
single-process mode).


From kboo at ca.ibm.com  Thu May 23 09:58:45 2013
From: kboo at ca.ibm.com (Kihup Boo)
Date: Thu, 23 May 2013 09:58:45 -0400
Subject: how to get the socket module compiled with SSL support
Message-ID: <OFA74B9882.89D804D7-ON85257B74.004C537A-85257B74.004CCA43@ca.ibm.com>


I am trying to make an HTTPS connection and read that HTTPS support is only
available if the socket module was compiled with SSL support.

http://www.jython.org/docs/library/httplib.html

Can someone elaborate on this? Where can I get the socket module for HTTPS,
or how do I build one if I have to?

Thanks,
- Kihup
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From rosuav at gmail.com  Thu May 23 10:16:06 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 00:16:06 +1000
Subject: how to get the socket module compiled with SSL support
In-Reply-To: <OFA74B9882.89D804D7-ON85257B74.004C537A-85257B74.004CCA43@ca.ibm.com>
References: <OFA74B9882.89D804D7-ON85257B74.004C537A-85257B74.004CCA43@ca.ibm.com>
Message-ID: <CAPTjJmr-k3kvc7ybTROqB7zRYwb5f86KRitwNXbdqh18BStqaA@mail.gmail.com>

On Thu, May 23, 2013 at 11:58 PM, Kihup Boo <kboo at ca.ibm.com> wrote:
> I am trying to make an HTTPS connection and read that HTTPS support is only
> available if the socket module was compiled with SSL support.
>
> http://www.jython.org/docs/library/httplib.html
>
> Can someone elaborate on this? Where can I get the socket module for HTTPS,
> or how do I build one if I have to?

If you got a standard download, chances are it's going to have SSL
support. What error are you getting? Is it specifically telling you
that SSL support is not available? Post a minimal script and its
actual failure.

ChrisA


From tjreedy at udel.edu  Thu May 23 16:22:34 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Thu, 23 May 2013 16:22:34 -0400
Subject: how to get the socket module compiled with SSL support
In-Reply-To: <OFA74B9882.89D804D7-ON85257B74.004C537A-85257B74.004CCA43@ca.ibm.com>
References: <OFA74B9882.89D804D7-ON85257B74.004C537A-85257B74.004CCA43@ca.ibm.com>
Message-ID: <knltq0$6b1$2@ger.gmane.org>

On 5/23/2013 9:58 AM, Kihup Boo wrote:
> I am trying to make an HTTPS connection and read that HTTPS support is
> only available if the socket module was compiled with SSL support.
>
> _http://www.jython.org/docs/library/httplib.html_
>
> Can someone elaborate on this? Where can I get the socket module for
> HTTPS, or how do I build one if I have to?

This is mostly a CPython oriented list. Any prebuilt CPython binary you 
get likely has SSL support compiled in. If you want to know about the 
jython socket module, you should check on a jython list, or just try it.




From asianavatar at gmail.com  Thu May 23 11:48:59 2013
From: asianavatar at gmail.com (asianavatar at gmail.com)
Date: Thu, 23 May 2013 08:48:59 -0700 (PDT)
Subject: Error with python 3.3.2 and https
Message-ID: <683480d3-9b36-40f3-af61-e767178ceb87@googlegroups.com>

I am trying to write a program that requires me hitting a https web link. However, I can't seem to get it to work. The program works fine when dealing with http sites, however, when I try it with a https site I get

socket.gaierror: [Errno 11001] getaddrinfo failed

It seems like it has something to do with the ssl not working, however, I do have the ssl.py in the python library and I have no problem importing it.

My code is below. Any help would be greatly appreciated.

import urllib.request
auth = urllib.request.HTTPSHandler()
proxy = urllib.request.ProxyHandler({'http':'my proxy'})
opener = urllib.request.build_opener(proxy, auth)
f = opener.open('http://www.google.ca/')


From rosuav at gmail.com  Thu May 23 11:56:11 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 01:56:11 +1000
Subject: Error with python 3.3.2 and https
In-Reply-To: <683480d3-9b36-40f3-af61-e767178ceb87@googlegroups.com>
References: <683480d3-9b36-40f3-af61-e767178ceb87@googlegroups.com>
Message-ID: <CAPTjJmoo6YJowLfY882sYFuk=+pSUdwCaXN417pbHwh8ARA7Jg@mail.gmail.com>

On Fri, May 24, 2013 at 1:48 AM,  <asianavatar at gmail.com> wrote:
> I am trying to write a program that requires me hitting a https web link. However, I can't seem to get it to work. The program works fine when dealing with http sites, however, when I try it with a https site I get
>
> socket.gaierror: [Errno 11001] getaddrinfo failed
>
> It seems like it has something to do with the ssl not working, however, I do have the ssl.py in the python library and I have no problem importing it.
>
> My code is below. Any help would be greatly appreciated.
>
> import urllib.request
> auth = urllib.request.HTTPSHandler()
> proxy = urllib.request.ProxyHandler({'http':'my proxy'})
> opener = urllib.request.build_opener(proxy, auth)
> f = opener.open('http://www.google.ca/')

Check the name of your proxy; maybe you can't resolve it. Can you
identify your proxy by IP address?

By omitting the proxy part, I can quite happily make a direct request
using code like yours.

ChrisA


From asianavatar at gmail.com  Thu May 23 12:12:44 2013
From: asianavatar at gmail.com (asianavatar at gmail.com)
Date: Thu, 23 May 2013 09:12:44 -0700 (PDT)
Subject: Error with python 3.3.2 and https
In-Reply-To: <mailman.2019.1369324579.3114.python-list@python.org>
References: <683480d3-9b36-40f3-af61-e767178ceb87@googlegroups.com>
	<mailman.2019.1369324579.3114.python-list@python.org>
Message-ID: <77525aba-65fc-41c3-aeb5-428d66719bee@googlegroups.com>

I only have the http of the proxy. I guess I could find out the ip of it. However, even if I use the http proxy address, why would it work for a http site and not a https site if its the proxy that can't resolve.


From rosuav at gmail.com  Thu May 23 12:18:04 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 02:18:04 +1000
Subject: Error with python 3.3.2 and https
In-Reply-To: <77525aba-65fc-41c3-aeb5-428d66719bee@googlegroups.com>
References: <683480d3-9b36-40f3-af61-e767178ceb87@googlegroups.com>
	<mailman.2019.1369324579.3114.python-list@python.org>
	<77525aba-65fc-41c3-aeb5-428d66719bee@googlegroups.com>
Message-ID: <CAPTjJmqYr=iQkU00TGqmyo6iYC0KJ3d3zVvzunyKSx93tn9yMA@mail.gmail.com>

On Fri, May 24, 2013 at 2:12 AM,  <asianavatar at gmail.com> wrote:
> I only have the http of the proxy. I guess I could find out the ip of it. However, even if I use the http proxy address, why would it work for a http site and not a https site if its the proxy that can't resolve.

Can you post working code for HTTP and nonworking for HTTPS? There was
no SSL in the code you posted. Or are you saying it's really just that
you change the URL and it stops working? If so, I don't think we can
test it without having your proxy... you may want to talk to whoever
controls the proxy.

ChrisA


From asianavatar at gmail.com  Thu May 23 13:49:55 2013
From: asianavatar at gmail.com (asianavatar at gmail.com)
Date: Thu, 23 May 2013 10:49:55 -0700 (PDT)
Subject: Error with python 3.3.2 and https
In-Reply-To: <mailman.2021.1369325893.3114.python-list@python.org>
References: <683480d3-9b36-40f3-af61-e767178ceb87@googlegroups.com>
	<mailman.2019.1369324579.3114.python-list@python.org>
	<77525aba-65fc-41c3-aeb5-428d66719bee@googlegroups.com>
	<mailman.2021.1369325893.3114.python-list@python.org>
Message-ID: <f90d099d-e794-4164-b796-4db3a9f95cc5@googlegroups.com>


Yeah that is the case. Once I change the f = opener.open('website') line to a link that has a https I get that socket error. Nothing else changes. I was reading online and came across this site which shows you how if the version of python installed supports ssl.

http://morlockhq.blogspot.ca/2008/05/python-tip-checking-to-see-if-your.html

When I followed the instructions I got that it wasn't supported, although the ssl.py is in the lib directory. Python was installed from the official python page using the windows installer. Is somehow ssl disabled by default? Do I need to get a third party ssl module?



From rosuav at gmail.com  Thu May 23 18:23:55 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 08:23:55 +1000
Subject: Error with python 3.3.2 and https
In-Reply-To: <f90d099d-e794-4164-b796-4db3a9f95cc5@googlegroups.com>
References: <683480d3-9b36-40f3-af61-e767178ceb87@googlegroups.com>
	<mailman.2019.1369324579.3114.python-list@python.org>
	<77525aba-65fc-41c3-aeb5-428d66719bee@googlegroups.com>
	<mailman.2021.1369325893.3114.python-list@python.org>
	<f90d099d-e794-4164-b796-4db3a9f95cc5@googlegroups.com>
Message-ID: <CAPTjJmrynSm+ggSQ1+wULJg9ggi1OYANnp6iqh1V+pUN6GdVGA@mail.gmail.com>

On Fri, May 24, 2013 at 3:49 AM,  <asianavatar at gmail.com> wrote:
>
> Yeah that is the case. Once I change the f = opener.open('website') line to a link that has a https I get that socket error. Nothing else changes. I was reading online and came across this site which shows you how if the version of python installed supports ssl.
>
> http://morlockhq.blogspot.ca/2008/05/python-tip-checking-to-see-if-your.html
>
> When I followed the instructions I got that it wasn't supported, although the ssl.py is in the lib directory. Python was installed from the official python page using the windows installer. Is somehow ssl disabled by default? Do I need to get a third party ssl module?

Hrm. Unfortunately those instructions don't work for Python 3... or at
least, if they do, then both of my handy installations (one Windows,
one Linux) don't have SSL. However, I *can* do 'import ssl' and
'import _ssl', the latter of which is what Lib/socket.py checks for.
In Python 3.3's Lib/socket.py there's no mention of ssl anywhere, so
I'd be inclined to look elsewhere for support checks.

ChrisA


From asianavatar at gmail.com  Fri May 24 14:08:13 2013
From: asianavatar at gmail.com (asianavatar at gmail.com)
Date: Fri, 24 May 2013 11:08:13 -0700 (PDT)
Subject: Error with python 3.3.2 and https
In-Reply-To: <mailman.2041.1369347839.3114.python-list@python.org>
References: <683480d3-9b36-40f3-af61-e767178ceb87@googlegroups.com>
	<mailman.2019.1369324579.3114.python-list@python.org>
	<77525aba-65fc-41c3-aeb5-428d66719bee@googlegroups.com>
	<mailman.2021.1369325893.3114.python-list@python.org>
	<f90d099d-e794-4164-b796-4db3a9f95cc5@googlegroups.com>
	<mailman.2041.1369347839.3114.python-list@python.org>
Message-ID: <d0d9303e-4782-4e24-a45f-6458e72aa691@googlegroups.com>

So apparently switching the http to https in the proxyHandler call did the trick. Thanks for all the help.


From aeaprog at gmail.com  Thu May 23 12:09:31 2013
From: aeaprog at gmail.com (Andrew Edwards-Adams)
Date: Thu, 23 May 2013 09:09:31 -0700 (PDT)
Subject: Accessing Json data (I think I am nearly there) complete beginner
Message-ID: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>

Hey guys
I think its worth stating that I have been trying to code for 1 week. 
I am trying to access some Json data. My innitial code was the below: 

"import mechanize
import urllib
import re
 
def getData():  
    post_url = "http://www.tweetnaps.co.uk/leaderboards/leaderboard_json/all_time"
    browser = mechanize.Browser()
    browser.set_handle_robots(False)
    browser.addheaders = [('User-agent', 'Firefox')]
 
    #These are the parameters you've got from checking with the aforementioned tools
    parameters = {'page' : '1',
                  'rp' : '10',
                  'sortname' : 'total_pl',
                  'sortorder' : 'desc'}
    #Encode the parameters
    data = urllib.urlencode(parameters)
    trans_array = browser.open(post_url,data).read().decode('UTF-8')
 
    #print trans_array

    myfile = open("test.txt", "w")
    myfile.write(trans_array)
    myfile.close()

getData()
 
raw_input("Complete")"

I was recommended to use the following code to access the Json data directly, however I cannot get it to return anything. I think the guy that recommended me this method must have got something wrong? Or perhaps I am simply incompetent: 

import mechanize
import urllib
import json
def getData():  
    post_url = "http://www.tweetnaps.co.uk/leaderboards/leaderboard_json/current_week"
    browser = mechanize.Browser()
    browser.set_handle_robots(False)
    browser.addheaders = [('User-agent', 'Firefox')]
 
    #These are the parameters you've got from checking with the aforementioned tools
    parameters = {'page' : '1',
                  'rp' : '50',
                  'sortname' : 'total_pl',
                  'sortorder' : 'desc'
                 }
    #Encode the parameters
    data = urllib.urlencode(parameters)
    trans_array = browser.open(post_url,data).read().decode('UTF-8')
 
    text1 = json.loads(trans_array)
    print text1['rows'][0]['id']  #play around with these values to access different data..
   
getData()

He told me to "#play around with these values to access different data.." really cant get anything out of this, any ideas? 

Many thanks AEA


From bahamutzero8825 at gmail.com  Thu May 23 12:40:49 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Thu, 23 May 2013 11:40:49 -0500
Subject: Accessing Json data (I think I am nearly there) complete beginner
In-Reply-To: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
References: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
Message-ID: <519E4691.4060600@gmail.com>

On 2013.05.23 11:09, Andrew Edwards-Adams wrote:
> I was recommended to use the following code to access the Json data directly, however I cannot get it to return anything.
Where exactly is the problem? Do you not get JSON back? Do you get the wrong values? Do you get a KeyError or IndexError trying to get
values from text1? Are there gremlins going around flipping bits in memory? It's good that you posted code, but "really cant get anything
out of this" isn't very useful.
-- 
CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1


From python at mrabarnett.plus.com  Thu May 23 12:53:23 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 23 May 2013 17:53:23 +0100
Subject: Accessing Json data (I think I am nearly there) complete beginner
In-Reply-To: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
References: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
Message-ID: <519E4983.40003@mrabarnett.plus.com>

On 23/05/2013 17:09, Andrew Edwards-Adams wrote:
> Hey guys
> I think its worth stating that I have been trying to code for 1 week.
> I am trying to access some Json data. My innitial code was the below:
>
> "import mechanize
> import urllib
> import re
>
> def getData():
>      post_url = "http://www.tweetnaps.co.uk/leaderboards/leaderboard_json/all_time"
>      browser = mechanize.Browser()
>      browser.set_handle_robots(False)
>      browser.addheaders = [('User-agent', 'Firefox')]
>
>      #These are the parameters you've got from checking with the aforementioned tools
>      parameters = {'page' : '1',
>                    'rp' : '10',
>                    'sortname' : 'total_pl',
>                    'sortorder' : 'desc'}
>      #Encode the parameters
>      data = urllib.urlencode(parameters)
>      trans_array = browser.open(post_url,data).read().decode('UTF-8')
>
>      #print trans_array
>
>      myfile = open("test.txt", "w")
>      myfile.write(trans_array)
>      myfile.close()
>
> getData()
>
> raw_input("Complete")"
>
> I was recommended to use the following code to access the Json data directly, however I cannot get it to return anything. I think the guy that recommended me this method must have got something wrong? Or perhaps I am simply incompetent:
>
> import mechanize
> import urllib
> import json
> def getData():
>      post_url = "http://www.tweetnaps.co.uk/leaderboards/leaderboard_json/current_week"
>      browser = mechanize.Browser()
>      browser.set_handle_robots(False)
>      browser.addheaders = [('User-agent', 'Firefox')]
>
>      #These are the parameters you've got from checking with the aforementioned tools
>      parameters = {'page' : '1',
>                    'rp' : '50',
>                    'sortname' : 'total_pl',
>                    'sortorder' : 'desc'
>                   }
>      #Encode the parameters
>      data = urllib.urlencode(parameters)
>      trans_array = browser.open(post_url,data).read().decode('UTF-8')
>
>      text1 = json.loads(trans_array)
>      print text1['rows'][0]['id']  #play around with these values to access different data..
>
> getData()
>
> He told me to "#play around with these values to access different data.." really cant get anything out of this, any ideas?
>
> Many thanks AEA
>
I've just tried it. It prints "1048".


From aeaprog at gmail.com  Thu May 23 12:58:17 2013
From: aeaprog at gmail.com (Andrew Edwards-Adams)
Date: Thu, 23 May 2013 09:58:17 -0700 (PDT)
Subject: Accessing Json data (I think I am nearly there) complete beginner
In-Reply-To: <mailman.2022.1369327254.3114.python-list@python.org>
References: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
	<mailman.2022.1369327254.3114.python-list@python.org>
Message-ID: <b7d6a9ac-4bff-45be-9db9-89d860796872@googlegroups.com>

On Thursday, May 23, 2013 5:40:49 PM UTC+1, Andrew Berg wrote:
> On 2013.05.23 11:09, Andrew Edwards-Adams wrote:
> 
> > I was recommended to use the following code to access the Json data directly, however I cannot get it to return anything.
> 
> Where exactly is the problem? Do you not get JSON back? Do you get the wrong values? Do you get a KeyError or IndexError trying to get
> 
> values from text1? Are there gremlins going around flipping bits in memory? It's good that you posted code, but "really cant get anything
> 
> out of this" isn't very useful.
> 
> -- 
> 
> CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1

Hi thanks for the reply Andrew, my first bit of code was heading in the right direction I was managing to pull out the usernames from the JSON, using REGEX. I was told that the second piece of code is the more efficient way to pull data from the JSON. When I say it doesnt do anything I can adjust the areas suggested. But it returns nothing, I just get the "= Restart =" line appear in the python shell. If there was a trackback/debug I might know where to look, but its not yielding errors, its simply yielding nothing. What i dont know, is if it is the code that isnt working, or what I am inputting in the " print text1['rows'][0]['id']" that isnt working.


Since this code: 

import mechanize
import urllib
import json
def getData():  
    post_url = "http://www.tweetnaps.co.uk/leaderboards/leaderboard_json/current_week"
    browser = mechanize.Browser()
    browser.set_handle_robots(False)
    browser.addheaders = [('User-agent', 'Firefox')]
 
    #These are the parameters you've got from checking with the aforementioned tools
    parameters = {'page' : '1',
                  'rp' : '50',
                  'sortname' : 'total_pl',
                  'sortorder' : 'desc'
                 }
    #Encode the parameters
    data = urllib.urlencode(parameters)
    trans_array = browser.open(post_url,data).read().decode('UTF-8')

 appears in both examples and my first attempt is definitely returning data from the JSON, I can only assume that the error is in the last two lines of his code, or as stated my imputing incorrect parameters.

:S


From bahamutzero8825 at gmail.com  Thu May 23 13:59:54 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Thu, 23 May 2013 12:59:54 -0500
Subject: Accessing Json data (I think I am nearly there) complete beginner
In-Reply-To: <b7d6a9ac-4bff-45be-9db9-89d860796872@googlegroups.com>
References: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
	<mailman.2022.1369327254.3114.python-list@python.org>
	<b7d6a9ac-4bff-45be-9db9-89d860796872@googlegroups.com>
Message-ID: <519E591A.6040400@gmail.com>

On 2013.05.23 11:58, Andrew Edwards-Adams wrote:
> If there was a trackback/debug I might know where to look, but its not yielding errors, its simply yielding nothing. What i dont know, is if it is the code that isnt working, or what I am inputting in the " print text1['rows'][0]['id']" that isnt working.
If fed a valid JSON object, json.loads() will return a regular dictionary. You can print (or pretty print with the pprint module) text1 to
see everything. If you're not familiar with dictionaries and lists, thoroughly read the tutorial before writing or modifying any more code.
http://docs.python.org/2/library/json.html#json.loads
-- 
CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1


From bahamutzero8825 at gmail.com  Thu May 23 14:11:28 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Thu, 23 May 2013 13:11:28 -0500
Subject: Accessing Json data (I think I am nearly there) complete beginner
In-Reply-To: <b7d6a9ac-4bff-45be-9db9-89d860796872@googlegroups.com>
References: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
	<mailman.2022.1369327254.3114.python-list@python.org>
	<b7d6a9ac-4bff-45be-9db9-89d860796872@googlegroups.com>
Message-ID: <519E5BD0.5080303@gmail.com>

On 2013.05.23 11:58, Andrew Edwards-Adams wrote:
> Hi thanks for the reply Andrew, my first bit of code was heading in the right direction I was managing to pull out the usernames from the JSON, using REGEX.
It's also worth mentioning that regexes are almost always the wrong tool, especially for standardized formats like JSON. They can be very
useful when nothing saner will get the job done, but are a nasty mess with no real benefit otherwise.
-- 
CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1


From aeaprog at gmail.com  Thu May 23 14:19:49 2013
From: aeaprog at gmail.com (Andrew Edwards-Adams)
Date: Thu, 23 May 2013 11:19:49 -0700 (PDT)
Subject: Accessing Json data (I think I am nearly there) complete beginner
In-Reply-To: <mailman.2026.1369332693.3114.python-list@python.org>
References: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
	<mailman.2022.1369327254.3114.python-list@python.org>
	<b7d6a9ac-4bff-45be-9db9-89d860796872@googlegroups.com>
	<mailman.2026.1369332693.3114.python-list@python.org>
Message-ID: <c9d46774-64c9-40f0-8589-6d261382ee5a@googlegroups.com>

On Thursday, May 23, 2013 7:11:28 PM UTC+1, Andrew Berg wrote:
> On 2013.05.23 11:58, Andrew Edwards-Adams wrote:
> 
> > Hi thanks for the reply Andrew, my first bit of code was heading in the right direction I was managing to pull out the usernames from the JSON, using REGEX.
> 
> It's also worth mentioning that regexes are almost always the wrong tool, especially for standardized formats like JSON. They can be very
> 
> useful when nothing saner will get the job done, but are a nasty mess with no real benefit otherwise.
> 
> -- 
> 
> CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1

Thanks Andrew, yes I believe this is what the guy who provided me with the code was thinking. I was about to embark on what was definitely going to be an inefficient long regex.


From breamoreboy at yahoo.co.uk  Thu May 23 14:56:19 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 23 May 2013 19:56:19 +0100
Subject: Accessing Json data (I think I am nearly there) complete beginner
In-Reply-To: <c9d46774-64c9-40f0-8589-6d261382ee5a@googlegroups.com>
References: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
	<mailman.2022.1369327254.3114.python-list@python.org>
	<b7d6a9ac-4bff-45be-9db9-89d860796872@googlegroups.com>
	<mailman.2026.1369332693.3114.python-list@python.org>
	<c9d46774-64c9-40f0-8589-6d261382ee5a@googlegroups.com>
Message-ID: <knloo0$gnc$1@ger.gmane.org>

On 23/05/2013 19:19, Andrew Edwards-Adams wrote:
> On Thursday, May 23, 2013 7:11:28 PM UTC+1, Andrew Berg wrote:
>> On 2013.05.23 11:58, Andrew Edwards-Adams wrote:
>>
>>> Hi thanks for the reply Andrew, my first bit of code was heading in the right direction I was managing to pull out the usernames from the JSON, using REGEX.
>>
>> It's also worth mentioning that regexes are almost always the wrong tool, especially for standardized formats like JSON. They can be very
>>
>> useful when nothing saner will get the job done, but are a nasty mess with no real benefit otherwise.
>>
>> --
>>
>> CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1
>
> Thanks Andrew, yes I believe this is what the guy who provided me with the code was thinking. I was about to embark on what was definitely going to be an inefficient long regex.
>

Funny old world, there doesn't appear to be working code but someone is 
already thinking about definite inefficiency.  What evidence do you have 
to support this claim?

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From aeaprog at gmail.com  Thu May 23 17:30:05 2013
From: aeaprog at gmail.com (Andrew Edwards-Adams)
Date: Thu, 23 May 2013 14:30:05 -0700 (PDT)
Subject: Accessing Json data (I think I am nearly there) complete beginner
In-Reply-To: <mailman.2030.1369335379.3114.python-list@python.org>
References: <509030d9-08fd-40b2-8a89-cd4ecfad7a1a@googlegroups.com>
	<mailman.2022.1369327254.3114.python-list@python.org>
	<b7d6a9ac-4bff-45be-9db9-89d860796872@googlegroups.com>
	<mailman.2026.1369332693.3114.python-list@python.org>
	<c9d46774-64c9-40f0-8589-6d261382ee5a@googlegroups.com>
	<mailman.2030.1369335379.3114.python-list@python.org>
Message-ID: <e7aa9c8e-c189-49f5-aa70-7def68b513bc@googlegroups.com>

On Thursday, May 23, 2013 7:56:19 PM UTC+1, Mark Lawrence wrote:
> On 23/05/2013 19:19, Andrew Edwards-Adams wrote:
> 
> > On Thursday, May 23, 2013 7:11:28 PM UTC+1, Andrew Berg wrote:
> 
> >> On 2013.05.23 11:58, Andrew Edwards-Adams wrote:
> 
> >>
> 
> >>> Hi thanks for the reply Andrew, my first bit of code was heading in the right direction I was managing to pull out the usernames from the JSON, using REGEX.
> 
> >>
> 
> >> It's also worth mentioning that regexes are almost always the wrong tool, especially for standardized formats like JSON. They can be very
> 
> >>
> 
> >> useful when nothing saner will get the job done, but are a nasty mess with no real benefit otherwise.
> 
> >>
> 
> >> --
> 
> >>
> 
> >> CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1
> 
> >
> 
> > Thanks Andrew, yes I believe this is what the guy who provided me with the code was thinking. I was about to embark on what was definitely going to be an inefficient long regex.
> 
> >
> 
> 
> 
> Funny old world, there doesn't appear to be working code but someone is 
> 
> already thinking about definite inefficiency.  What evidence do you have 
> 
> to support this claim?
> 
> 
> 
> -- 
> 
> If you're using GoogleCrap? please read this 
> 
> http://wiki.python.org/moin/GoogleGroupsPython.
> 
> 
> 
> Mark Lawrence

haha true Mark, I have made mistakes like this before become ok at coding VBA to achieve things in the most inefficient manner possible. Something that I will learn from for the current python coding project.


From anadionisio257 at gmail.com  Thu May 23 12:28:44 2013
From: anadionisio257 at gmail.com (=?ISO-8859-1?Q?Ana_Dion=EDsio?=)
Date: Thu, 23 May 2013 09:28:44 -0700 (PDT)
Subject: Pulp problem _dummy
Message-ID: <d2c9e965-c70b-42a3-af08-f182b2b4b246@googlegroups.com>

Hello!

I'm using pulp for linear optimization but when I run my code I get the following output:

Central Optimization:
MAXIMIZE
0*__dummy + 0

SUBJECT TO
_C1: 2 T0 >= 0

_C2: 2 T0 <= 0

_C3: 0.0686928673545 Frigorifico0 >= 0

_C4: 0.0686928673545 Frigorifico0 <= 0

_C5: 2 Termo0 >= 0

_C6: 2 Termo0 <= 0

_C7: 0.0686928673545 F0 >= 0

_C8: 0.0686928673545 F0 <= 0

_C9: 2 T1 >= 0

_C10: 2 T1 <= 0

_C11: 0.0686928673545 Frigorifico1 >= 0

_C12: 0.0686928673545 Frigorifico1 <= 0

_C13: 2 Termo0 >= 0

_C14: 2 Termo0 <= 0

_C15: 0.0686928673545 F0 >= 0

_C16: 0.0686928673545 F0 <= 0

_C17: - AC0 - VE0 - 2 T0 - 0.0686928673545 F0 - AC1 - VE1
 - 2 T1 - 0.0686928673545 F1 >= -15

VARIABLES
AC0 <= 2.75 Continuous
VE0 = 0 Continuous
0 <= T0 <= 1 Integer
0 <= F0 <= 1 Integer
AC1 <= 2.75 Continuous
VE1 = 0 Continuous
0 <= T1 <= 1 Integer
0 <= F1 <= 1 Integer
__dummy = 0 Continuous

I don't know if this is enough information for you but if you couold help me I would be very very grateful

Thank you!


From m.gilson1 at gmail.com  Thu May 23 14:52:07 2013
From: m.gilson1 at gmail.com (Matthew Gilson)
Date: Thu, 23 May 2013 14:52:07 -0400
Subject: Non-identifiers in dictionary keys for **expression syntax
Message-ID: <519E6557.6050405@gmail.com>

This is a question regarding the documentation around dictionary 
unpacking.  The documentation for the call syntax 
(http://docs.python.org/3/reference/expressions.html#grammar-token-call) 
says:

"If the syntax **expression appears in the function call, expression 
must evaluate to a mapping, the contents of which are treated as 
additional keyword arguments."

That's fine, but what is a keyword argument?  According to the glossary 
(http://docs.python.org/3.3/glossary.html):

/"keyword argument/: an argument preceded by an identifier (e.g. name=) 
in a function call or passed as a value in a dictionary preceded by **."

As far as I'm concerned, this leads to some ambiguity in whether the 
keys of the mapping need to be valid identifiers or not.

Using Cpython, we can do the following:

      def func(**kwargs):
           print kwargs

      d = {'foo bar baz':3}

So that might lead us to believe that the keys of the mapping do not 
need to be valid identifiers.  However, the previous function does not 
work with the following dictionary:

     d = {1:3}

because not all the keys are strings.  Is there a way to petition to get 
this more rigorously defined?

Thanks,
~Matt



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From neilc at norwich.edu  Thu May 23 15:20:44 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 23 May 2013 19:20:44 GMT
Subject: Non-identifiers in dictionary keys for **expression syntax
References: <mailman.2029.1369335137.3114.python-list@python.org>
Message-ID: <b078gcF5qh7U1@mid.individual.net>

On 2013-05-23, Matthew Gilson <m.gilson1 at gmail.com> wrote:
> That's fine, but what is a keyword argument?  According to the glossary 
> (http://docs.python.org/3.3/glossary.html):
>
> /"keyword argument/: an argument preceded by an identifier (e.g. name=) 
> in a function call or passed as a value in a dictionary preceded by **."
>
> As far as I'm concerned, this leads to some ambiguity in
> whether the keys of the mapping need to be valid identifiers or
> not.

I don't see any ambiguity. A keyword argument is an argument
preceded by an identifier according to the definition. Where are
you perceiving wiggle room?

-- 
Neil Cerutti


From ethan at stoneleaf.us  Thu May 23 15:37:18 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Thu, 23 May 2013 12:37:18 -0700
Subject: Non-identifiers in dictionary keys for **expression syntax
In-Reply-To: <b078gcF5qh7U1@mid.individual.net>
References: <mailman.2029.1369335137.3114.python-list@python.org>
	<b078gcF5qh7U1@mid.individual.net>
Message-ID: <519E6FEE.403@stoneleaf.us>

On 05/23/2013 12:20 PM, Neil Cerutti wrote:
> On 2013-05-23, Matthew Gilson <m.gilson1 at gmail.com> wrote:
>>
>> That's fine, but what is a keyword argument?  According to the glossary
>> (http://docs.python.org/3.3/glossary.html):
>>
>> /"keyword argument/: an argument preceded by an identifier (e.g. name=)
>> in a function call or passed as a value in a dictionary preceded by **."
>>
>> As far as I'm concerned, this leads to some ambiguity in
>> whether the keys of the mapping need to be valid identifiers or
>> not.
>
> I don't see any ambiguity. A keyword argument is an argument
> preceded by an identifier according to the definition. Where are
> you perceiving wiggle room?

--> def func(**kwargs):
...     print(kwargs)
...

--> d = {'foo bar baz':3}

--> func(**d)
{'foo bar baz': 3}

Even though 'foo bar baz' is not a valid identifier, and could not be passed as `func(foo bar baz = 3)`, it still worked 
when going through a dict.

--
~Ethan~


From m.gilson1 at gmail.com  Thu May 23 16:49:19 2013
From: m.gilson1 at gmail.com (Matthew Gilson)
Date: Thu, 23 May 2013 16:49:19 -0400
Subject: Non-identifiers in dictionary keys for **expression syntax
In-Reply-To: <b078gcF5qh7U1@mid.individual.net>
References: <mailman.2029.1369335137.3114.python-list@python.org>
	<b078gcF5qh7U1@mid.individual.net>
Message-ID: <519E80CF.4060803@gmail.com>


On 05/23/2013 03:20 PM, Neil Cerutti wrote:
> On 2013-05-23, Matthew Gilson <m.gilson1 at gmail.com> wrote:
>> That's fine, but what is a keyword argument?  According to the glossary
>> (http://docs.python.org/3.3/glossary.html):
>>
>> /"keyword argument/: an argument preceded by an identifier (e.g. name=)
>> in a function call or passed as a value in a dictionary preceded by **."
>>
>> As far as I'm concerned, this leads to some ambiguity in
>> whether the keys of the mapping need to be valid identifiers or
>> not.
> I don't see any ambiguity. A keyword argument is an argument
> preceded by an identifier according to the definition. Where are
> you perceiving wiggle room?
>
The wiggle room comes from the "or passed as a value in a dictionary" 
clause.  We sort of get caught in a infinite loop there because the 
stuff that can be passed in a dictionary is a keyword which is an 
identifer=expression or something passed as a value in a dictionary ...

Also the fact that:

      func(**{"foo bar baz":1})

works even though `foo bar baz` isn't a valid identifier, but:

      func(**{1:3})

doesn't work.


From ian.g.kelly at gmail.com  Thu May 23 16:22:28 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 23 May 2013 14:22:28 -0600
Subject: Non-identifiers in dictionary keys for **expression syntax
In-Reply-To: <519E6557.6050405@gmail.com>
References: <519E6557.6050405@gmail.com>
Message-ID: <CALwzid=ZfAvQGRuDZ6RRf=ruifqgWAT1GPEiaFM0OT5UoA9D3A@mail.gmail.com>

On Thu, May 23, 2013 at 12:52 PM, Matthew Gilson <m.gilson1 at gmail.com> wrote:
> Using Cpython, we can do the following:
>
>      def func(**kwargs):
>           print kwargs
>
>      d = {'foo bar baz':3}
>
> So that might lead us to believe that the keys of the mapping do not need to
> be valid identifiers.  However, the previous function does not work with the
> following dictionary:
>
>     d = {1:3}
>
> because not all the keys are strings.  Is there a way to petition to get
> this more rigorously defined?

The string requirement is probably for optimization, but if the
argument is both sent and received using the ** syntax, is there a
good reason why only identifiers should be allowed?


From tjreedy at udel.edu  Thu May 23 16:52:11 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Thu, 23 May 2013 16:52:11 -0400
Subject: Non-identifiers in dictionary keys for **expression syntax
In-Reply-To: <519E6557.6050405@gmail.com>
References: <519E6557.6050405@gmail.com>
Message-ID: <knlvhh$qi9$1@ger.gmane.org>

On 5/23/2013 2:52 PM, Matthew Gilson wrote:
> This is a question regarding the documentation around dictionary
> unpacking.  The documentation for the call syntax
> (http://docs.python.org/3/reference/expressions.html#grammar-token-call)
> says:
>
> "If the syntax **expression appears in the function call, expression
> must evaluate to a mapping, the contents of which are treated as
> additional keyword arguments."
>
> That's fine, but what is a keyword argument?  According to the glossary
> (http://docs.python.org/3.3/glossary.html):
>
> /"keyword argument/: an argument preceded by an identifier (e.g. name=)
> in a function call or passed as a value in a dictionary preceded by **."

It appears that the requirement has been relaxed (in the previous 
quote), so that 'dictionary' should also be changed to 'mapping'. It 
might not hurt to add 'The key for the value should be an identifier.'
>
> As far as I'm concerned, this leads to some ambiguity in whether the
> keys of the mapping need to be valid identifiers or not.

I think you are being too lawyerly. The pretty clear and sensible 
implication is that the key for the value should be a string with a 
valid identifier. If it is anything else, you are on your own and 
deserve any joy or pain that results ;=)

> Using Cpython, we can do the following:
>
>       def func(**kwargs):
>            print kwargs
>
>       d = {'foo bar baz':3}
>
> So that might lead us to believe that the keys of the mapping do not
> need to be valid identifiers.

There are two ways to pass args to func to be gathered into kwargs; 
explicit key=val pairs and **mapping, or both.
func(a=1, b='hi', **{'foo bar baz':3})
#
{'foo bar baz': 3, 'a': 1, 'b': 'hi'}

So func should not expect anything other than identifier strings.

   However, the previous function does not
> work with the following dictionary:
>
>      d = {1:3}
>
> because not all the keys are strings.

So CPython checks that keys are strings, because that is cheap, but not 
that the strings are identifiers, because that would be more expensive. 
Just because an implementation allow somethings (omits a check) for 
efficiency does not mean you should do it.

globals()[1] = 1
works, but is not normally very sensible or useful.

>  Is there a way to petition to get this more rigorously defined?

bugs.python.org
The problem is that mandating a rigorous check by implementations makes 
Python slower to the detriment of sensible programmers.






From m.gilson1 at gmail.com  Thu May 23 17:15:15 2013
From: m.gilson1 at gmail.com (Matthew Gilson)
Date: Thu, 23 May 2013 17:15:15 -0400
Subject: Non-identifiers in dictionary keys for **expression syntax
In-Reply-To: <knlvhh$qi9$1@ger.gmane.org>
References: <519E6557.6050405@gmail.com> <knlvhh$qi9$1@ger.gmane.org>
Message-ID: <519E86E3.5000409@gmail.com>


On 05/23/2013 04:52 PM, Terry Jan Reedy wrote:
> On 5/23/2013 2:52 PM, Matthew Gilson wrote:
>> This is a question regarding the documentation around dictionary
>> unpacking.  The documentation for the call syntax
>> (http://docs.python.org/3/reference/expressions.html#grammar-token-call)
>> says:
>>
>> "If the syntax **expression appears in the function call, expression
>> must evaluate to a mapping, the contents of which are treated as
>> additional keyword arguments."
>>
>> That's fine, but what is a keyword argument?  According to the glossary
>> (http://docs.python.org/3.3/glossary.html):
>>
>> /"keyword argument/: an argument preceded by an identifier (e.g. name=)
>> in a function call or passed as a value in a dictionary preceded by **."
>
> It appears that the requirement has been relaxed (in the previous 
> quote), so that 'dictionary' should also be changed to 'mapping'. It 
> might not hurt to add 'The key for the value should be an identifier.'
>>
>> As far as I'm concerned, this leads to some ambiguity in whether the
>> keys of the mapping need to be valid identifiers or not.
>
> I think you are being too lawyerly. The pretty clear and sensible 
> implication is that the key for the value should be a string with a 
> valid identifier. If it is anything else, you are on your own and 
> deserve any joy or pain that results ;=)
>
>> Using Cpython, we can do the following:
>>
>>       def func(**kwargs):
>>            print kwargs
>>
>>       d = {'foo bar baz':3}
>>
>> So that might lead us to believe that the keys of the mapping do not
>> need to be valid identifiers.
>
> There are two ways to pass args to func to be gathered into kwargs; 
> explicit key=val pairs and **mapping, or both.
> func(a=1, b='hi', **{'foo bar baz':3})
> #
> {'foo bar baz': 3, 'a': 1, 'b': 'hi'}
>
> So func should not expect anything other than identifier strings.
>
>   However, the previous function does not
>> work with the following dictionary:
>>
>>      d = {1:3}
>>
>> because not all the keys are strings.
>
> So CPython checks that keys are strings, because that is cheap, but 
> not that the strings are identifiers, because that would be more 
> expensive. Just because an implementation allow somethings (omits a 
> check) for efficiency does not mean you should do it.
>
> globals()[1] = 1
> works, but is not normally very sensible or useful.
>
>>  Is there a way to petition to get this more rigorously defined?
>
> bugs.python.org
> The problem is that mandating a rigorous check by implementations 
> makes Python slower to the detriment of sensible programmers 

To be clear, you're saying that

      func(**{'foo bar baz':3})

is not supported (officially), but it works in CPython because checking 
that every string in the dict is a valid identifier would be costly.  Of 
course that is sensible and I don't think the behaviour should be 
changed "to the detriment of sensible programmers".  However, it would 
be nice if it was documented somewhere that the above function call is 
something that a non-sensible programmer would do.  Perhaps with a 
"CPython implementation detail" type of block.


From sloan949 at gmail.com  Thu May 23 16:49:02 2013
From: sloan949 at gmail.com (sloan949 at gmail.com)
Date: Thu, 23 May 2013 13:49:02 -0700 (PDT)
Subject: suppress newlines in my script
Message-ID: <52c74908-8bac-498e-9549-5b9500b152f1@googlegroups.com>

I am importing lines from an external csv file and when I iterate through the lines and increment, new lines are introduced.
How would I cut out the newlines.  I have attempted several pythonic strip() and rstrip() how can i implent this?


import sys, os

f=open('europe_csv')
lines=f.readlines()

BU = 'Company,,,,,,,,,,,,,,'
PPP = 'Pre-Prod,,,,,,,,Prod,,,,,,'
C1 = ',,,,,,,,,,,,,,'
Title = 'Site,Environment,'
NET1 = lines[4]
GW1 = lines[5]
M1 = lines[6]
PS1 = lines[7]
PE1 = lines[8]
C2 = ',,,,,,,,,,,,,,'
NET2 = lines[10]
GW2 = lines[11]
M2 = lines[12]
PS2 = lines[13]
PE2  = lines[14]



for count in range(64, 127):
 print NET1.format(count)
 print GW1.format(count)
 print M1
 print PS1.format(count)
 print PE1.format(count)
 print C2
 print NET2.format(count)
 print GW2.format(count)
 print M2
 print PS2.format(count)
 print PE2.format(count)



From sloan949 at gmail.com  Fri May 24 09:59:43 2013
From: sloan949 at gmail.com (sloan949 at gmail.com)
Date: Fri, 24 May 2013 06:59:43 -0700 (PDT)
Subject: suppress newlines in my script
In-Reply-To: <52c74908-8bac-498e-9549-5b9500b152f1@googlegroups.com>
References: <52c74908-8bac-498e-9549-5b9500b152f1@googlegroups.com>
Message-ID: <b52fcbed-3ea6-4352-99de-c6274c557016@googlegroups.com>

On Thursday, May 23, 2013 1:49:02 PM UTC-7, sloa... at gmail.com wrote:
> I am importing lines from an external csv file and when I iterate through the lines and increment, new lines are introduced.
> 
> How would I cut out the newlines.  I have attempted several pythonic strip() and rstrip() how can i implent this?
> 
> 
> 
> 
> 
> import sys, os
> 
> 
> 
> f=open('europe_csv')
> 
> lines=f.readlines()
> 
> 
> 
> BU = 'Company,,,,,,,,,,,,,,'
> 
> PPP = 'Pre-Prod,,,,,,,,Prod,,,,,,'
> 
> C1 = ',,,,,,,,,,,,,,'
> 
> Title = 'Site,Environment,'
> 
> NET1 = lines[4]
> 
> GW1 = lines[5]
> 
> M1 = lines[6]
> 
> PS1 = lines[7]
> 
> PE1 = lines[8]
> 
> C2 = ',,,,,,,,,,,,,,'
> 
> NET2 = lines[10]
> 
> GW2 = lines[11]
> 
> M2 = lines[12]
> 
> PS2 = lines[13]
> 
> PE2  = lines[14]
> 
> 
> 
> 
> 
> 
> 
> for count in range(64, 127):
> 
>  print NET1.format(count)
> 
>  print GW1.format(count)
> 
>  print M1
> 
>  print PS1.format(count)
> 
>  print PE1.format(count)
> 
>  print C2
> 
>  print NET2.format(count)
> 
>  print GW2.format(count)
> 
>  print M2
> 
>  print PS2.format(count)
> 
>  print PE2.format(count)

Thanks for the tip about the CSV module.  I did not know about that.   

Here are two lines from the CSV file:

,,172.20.{0}.0/27,172.20.{0}.32/27,172.20.{0}.64/27,29,172.20.{0}.96/27,,,,172.21.{0}.0/27,172.21.{0}.32/27,172.21.{0}.64/27,29,172.21.{0}.96/27
GW:,,172.20.{0}.1,172.20.{0}.33,172.20.{0}.65,,172.20.{0}.97,,GW:,,172.21.{0}.1,172.21.{0}.33,172.21.{0}.65,,172.21.{0}.97

This is the output:
,,,,,,,,,,,,,,

,,,,,,,,,,,,,,
GW:,,172.20.126.129,172.20.126.161,172.20.126.193,,172.20.126.225,,GW:,,172.21.126.129,172.21.126.161,172.21.126.193,,172.21.126.225

''''''''''''''''''

There are blank lines between and I am assuming that these are from newlines being introduced.

The idea of this script is/was to abstract the csv data so that I dont need to place them in the file as there are many seperate CSV files to import.

I hope I answered your questions.

The majority of the script is below.
#!/usr/bin/python

import sys, os
#import pdb

#pdb.set_trace()

f=open('europe_germanyfinalcsv')
lines=f.readlines()

BU = 'Europe Germany,,,,,,,,,,,,,,'
PPP = 'Pre-Prod,,,,,,,,Prod,,,,,,'
C1 = ',,,,,,,,,,,,,,'
Title = 'Site,Environment,vApp Web,vApp App,vApp Data,Hosts Per Net,Reserved,,Site,Environment,vApp Web,vApp App,vApp Data,Hosts Per Net,Reserved'
NET1 = lines[4]
GW1 = lines[5]
M1 = lines[6]
PS1 = lines[7]
PE1 = lines[8]


for count in range(64, 127):
 print NET1.format(count)
 print GW1.format(count)
 print M1
 print PS1.format(count)
 print PE1.format(count)


From davea at davea.name  Fri May 24 15:24:26 2013
From: davea at davea.name (Dave Angel)
Date: Fri, 24 May 2013 15:24:26 -0400
Subject: suppress newlines in my script
In-Reply-To: <b52fcbed-3ea6-4352-99de-c6274c557016@googlegroups.com>
References: <52c74908-8bac-498e-9549-5b9500b152f1@googlegroups.com>
	<b52fcbed-3ea6-4352-99de-c6274c557016@googlegroups.com>
Message-ID: <519FBE6A.2070908@davea.name>

On 05/24/2013 09:59 AM, sloan949 at gmail.com wrote:
>
              <SNIP massive double-spaced nonsense from googlegroups misuse,
          see   http://wiki.python.org/moin/GoogleGroupsPython >


>>   print PE2.format(count)
>
> Thanks for the tip about the CSV module.  I did not know about that.

So why aren't you using it?  There's not much point in solving "the 
newlines problem" if you're going to later switch to a library which 
doesn't have the problem.  The csv module will eliminate the newlines, 
and the commas, organizing your data for you directly (assuming this 
really is a csv file, and that the separator is comma).  None of your 
present code seems to believe it's a csv file, so maybe that's just a 
misdirection.




-- 
DaveA


From jsf80238 at gmail.com  Fri May 24 23:49:24 2013
From: jsf80238 at gmail.com (Jason Friedman)
Date: Fri, 24 May 2013 21:49:24 -0600
Subject: suppress newlines in my script
In-Reply-To: <b52fcbed-3ea6-4352-99de-c6274c557016@googlegroups.com>
References: <52c74908-8bac-498e-9549-5b9500b152f1@googlegroups.com>
	<b52fcbed-3ea6-4352-99de-c6274c557016@googlegroups.com>
Message-ID: <CANy1k1i9xG7XKVDy2OjxuC6CHcsNT9noChyz9ZVPr3EYNPa+5g@mail.gmail.com>

> Here are two lines from the CSV file:
> ,,172.20.{0}.0/27,172.20.{0}.32/27,172.20.{0}.64/27,29,172.20.{0}.96/27,,,,172.21.{0}.0/27,172.21.{0}.32/27,172.21.{0}.64/27,29,172.21.{0}.96/27
> GW:,,172.20.{0}.1,172.20.{0}.33,172.20.{0}.65,,172.20.{0}.97,,GW:,,172.21.{0}.1,172.21.{0}.33,172.21.{0}.65,,172.21.{0}.97
>
> This is the output:
> ,,,,,,,,,,,,,,
>
> ,,,,,,,,,,,,,,
> GW:,,172.20.126.129,172.20.126.161,172.20.126.193,,172.20.126.225,,GW:,,172.21.126.129,172.21.126.161,172.21.126.193,,172.21.126.225
>
> ''''''''''''''''''

When you say "this is the output" do you mean that is what you are
getting or that is what you want?  If that is what you are getting
please reply with what you want for output.


From avazquezr at grm.uci.cu  Thu May 23 19:36:21 2013
From: avazquezr at grm.uci.cu (avazquezr at grm.uci.cu)
Date: Thu, 23 May 2013 16:36:21 -0700
Subject: authentication with python-ldap
In-Reply-To: <mailman.11673.1369347759.3113.python-list@python.org>
References: <mailman.11673.1369347759.3113.python-list@python.org>
Message-ID: <20130523163621.Horde.5xisTMkLBHdRnqf13O6lQRA@correo.grm.uci.cu>

import ldap
conn = ldap.initialize("ldap://ldap.uci.cu")
conn.protocol_version = ldap.VERSION3
conn.simple_bind_s( "uid=xxx,dc=uci,dc=cu", "xxx" )

Result:

Traceback (most recent call last):
   File "<console>", line 1, in <module>
   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line  
207, in simple_bind_s
     return self.result(msgid,all=1,timeout=self.timeout)
   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line  
422, in result
     res_type,res_data,res_msgid = self.result2(msgid,all,timeout)
   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line  
426, in result2
     res_type, res_data, res_msgid, srv_ctrls = self.result3(msgid,all,timeout)
   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line  
432, in result3
     ldap_result = self._ldap_call(self._l.result3,msgid,all,timeout)
   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line  
96, in _ldap_call
     result = func(*args,**kwargs)
INVALID_CREDENTIALS: {'desc': 'Invalid credentials'}



     what is my mistake ????






From dieter at handshake.de  Sat May 25 02:01:01 2013
From: dieter at handshake.de (dieter)
Date: Sat, 25 May 2013 08:01:01 +0200
Subject: authentication with python-ldap
References: <mailman.11673.1369347759.3113.python-list@python.org>
	<20130523163621.Horde.5xisTMkLBHdRnqf13O6lQRA@correo.grm.uci.cu>
Message-ID: <87vc67ppia.fsf@handshake.de>

avazquezr at grm.uci.cu writes:

> import ldap
> conn = ldap.initialize("ldap://ldap.uci.cu")
> conn.protocol_version = ldap.VERSION3
> conn.simple_bind_s( "uid=xxx,dc=uci,dc=cu", "xxx" )
>
> Result:
>
> Traceback (most recent call last):
>   File "<console>", line 1, in <module>
>   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line
> 207, in simple_bind_s
>     return self.result(msgid,all=1,timeout=self.timeout)
>   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line
> 422, in result
>     res_type,res_data,res_msgid = self.result2(msgid,all,timeout)
>   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line
> 426, in result2
>     res_type, res_data, res_msgid, srv_ctrls = self.result3(msgid,all,timeout)
>   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line
> 432, in result3
>     ldap_result = self._ldap_call(self._l.result3,msgid,all,timeout)
>   File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line
> 96, in _ldap_call
>     result = func(*args,**kwargs)
> INVALID_CREDENTIALS: {'desc': 'Invalid credentials'}


You are accessing a protected operation of the LDAP server
and it (the server) rejects it due to invalid credentials.
You may have forgotten to pass on credentials (e.g. a password)
or the credentials do not fit to the specified user
(maybe the user does not exist at all).



From jaorozco at estudiantes.uci.cu  Sat May 25 14:00:28 2013
From: jaorozco at estudiantes.uci.cu (Jorge Alberto Diaz Orozco)
Date: Sat, 25 May 2013 14:00:28 -0400 (EDT)
Subject: authentication with python-ldap
In-Reply-To: <87vc67ppia.fsf@handshake.de>
Message-ID: <36e9845b-4b22-406d-b38c-056341454fd2@ucimail4.uci.cu>

I have been doing the same thing and I tried to use java for testing the credentials and they are correct. It works perfectly with java.
I really don?t know what we?re doing wrong.


You are accessing a protected operation of the LDAP server
and it (the server) rejects it due to invalid credentials.
You may have forgotten to pass on credentials (e.g. a password)
or the credentials do not fit to the specified user
(maybe the user does not exist at all).
http://www.uci.cu


From jcasale at activenetwerx.com  Sat May 25 14:25:18 2013
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Sat, 25 May 2013 18:25:18 +0000
Subject: authentication with python-ldap
In-Reply-To: <36e9845b-4b22-406d-b38c-056341454fd2@ucimail4.uci.cu>
References: <87vc67ppia.fsf@handshake.de>,
	<36e9845b-4b22-406d-b38c-056341454fd2@ucimail4.uci.cu>
Message-ID: <assp.08571388ca.07b3837a38244c68a46f988c7a425fd7@exch.activenetwerx.com>

> I have been doing the same thing and I tried to use java for testing the credentials and they are correct. It works perfectly with java.
> I really don?t know what we?re doing wrong.
>
>
> You are accessing a protected operation of the LDAP server
> and it (the server) rejects it due to invalid credentials.
> You may have forgotten to pass on credentials (e.g. a password)
> or the credentials do not fit to the specified user
> (maybe the user does not exist at all).

Depending on the directory (which we don't know) and the code as well, the way you auth
might be the problem. Possibly Java met the directory requirements with the methods you
used whereas they did not with Python given your code.

For example, certain operations in AD require specific transports to be used...

jlc

From dieter at handshake.de  Sun May 26 02:00:36 2013
From: dieter at handshake.de (Dieter Maurer)
Date: Sun, 26 May 2013 08:00:36 +0200
Subject: authentication with python-ldap
In-Reply-To: <36e9845b-4b22-406d-b38c-056341454fd2@ucimail4.uci.cu>
References: <87vc67ppia.fsf@handshake.de>
	<36e9845b-4b22-406d-b38c-056341454fd2@ucimail4.uci.cu>
Message-ID: <20897.42244.578422.235154@localhost.localdomain>

Jorge Alberto Diaz Orozco wrote at 2013-5-25 14:00 -0400:
>I have been doing the same thing and I tried to use java for testing the credentials and they are correct. It works perfectly with java.
>I really don?t know what we?re doing wrong.

Neither do I.

But the error message definitely originates from the LDAP server.
This means that the server sees different things for the
(successful) Java connection and the (unsuccessful) Python connection.
Maybe, you can convince your LDAP server administrator to configure
a form of logging that allows you to compare the two requests
(this may not be easy - because sensitive information is involved).
Comparing the requests may provide valuable clues towards the cause
of the problem.

One may also try some guesswork: There is an important difference
between Java and Python 2. Java uses unicode as the typical type
for text variables while in Python 2, you use normally the type "str"
for text. "str" means no unicode but encoded text.
When the Java-LDAP bridge passes text to the LDAP server, it must
encode the text - and maybe, it uses the correct encoding
(the one the LDAP server expects). The Python-LDAP bridge, on the other
hand, does not get unicode but "str" and likely passes the "str"
values directly. Thus, if your "str" values do not use the correct
encoding (the one expected by the LDAP server), things will not
work out correctly.

I expect the LDAP server to expect the "utf-8" encoding.
In this case, problems could be expected when the data
passed on to the LDAP server contains non ascii characters
while all ascii data should not see problems.



--
Dieter


From notreal at earthlink.net  Thu May 23 22:44:38 2013
From: notreal at earthlink.net (JackM)
Date: Thu, 23 May 2013 22:44:38 -0400
Subject: Read txt file, add to iptables not working on new host
Message-ID: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>

First, let me say that I have no knowledge of or experience with Python 
or Linux/Unix. I have a script which was written by a host tech person 
that ran via cron on my old server. It was designed to read IP addresses 
from a text file and add them to be blocked on iptables. That way, we 
could add or remove IPs without involving tech support daily. It worked 
great.

Then we changed hosts and this script is now throwing errors on the new 
server. This host runs Python 2.6.6. This is the script:

#!/usr/bin/python
import os,time

##Input, Output, and TimeStamp
inFile = open('/var/www/html/mydomain.com/banlist.txt','r')
logFile = open('/var/log/banList.log','w')
stamp = time.asctime(time.localtime())


##Daily Flush of blockList rules before re-applying Blocks
os.popen('/sbin/iptables -F INPUT')
logFile.write(stamp), logFile.write('\n'), logFile.write('Flushing 
Rules..\n')

##Loop to read in file and Apply rules to IPtables
for line in inFile.readlines():
	tmp = line.split(';')
  	IP = tmp[0]
	outPut = os.popen( '/sbin/iptables -A INPUT -s' + ' ' + IP + ' ' + '-j 
REJECT' )
	logFile.write(IP), logFile.write(' - Has been blocked '), 
logFile.write(stamp),logFile.write


The errors we're getting are like these:

Bad argument `174.37.65.204'
  Try `iptables -h' or 'iptables --help' for more information.
  Bad argument `94.159.162.182'
  Try `iptables -h' or 'iptables --help' for more information.
  Bad argument `95.134.132.98'
  Try `iptables -h' or 'iptables --help' for more information.
  etc.

Entries from the banlist.txt are like these:

200.193.54.138; February 9, 2013, 7:42 am <br>
87.120.57.4; February 9, 2013, 7:42 am <br>
82.206.129.160; February 9, 2013, 7:43 am <br>
etc.

I know the error points to a bad iptables command.
Can someone tell me what change(s) I need to make to this script to get 
it working again? Thanks.



-- 
My email address on the header is a non-monitored spam catching account. 
I can be reached via http://www.wvnh.net/contact.htm



From carlosnepomuceno at outlook.com  Thu May 23 23:10:48 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 24 May 2013 06:10:48 +0300
Subject: Read txt file, add to iptables not working on new host
In-Reply-To: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>
References: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>
Message-ID: <BLU176-W13A4A0C49F234350E041ABD7AB0@phx.gbl>

Send the output of the following commands:

uname -a
/sbin/iptables -V


----------------------------------------
> From: notreal at earthlink.net
> Subject: Read txt file, add to iptables not working on new host
> Date: Thu, 23 May 2013 22:44:38 -0400
> To: python-list at python.org
>
> First, let me say that I have no knowledge of or experience with Python
> or Linux/Unix. I have a script which was written by a host tech person
> that ran via cron on my old server. It was designed to read IP addresses
> from a text file and add them to be blocked on iptables. That way, we
> could add or remove IPs without involving tech support daily. It worked
> great.
>
> Then we changed hosts and this script is now throwing errors on the new
> server. This host runs Python 2.6.6. This is the script:
>
> #!/usr/bin/python
> import os,time
>
> ##Input, Output, and TimeStamp
> inFile = open('/var/www/html/mydomain.com/banlist.txt','r')
> logFile = open('/var/log/banList.log','w')
> stamp = time.asctime(time.localtime())
>
>
> ##Daily Flush of blockList rules before re-applying Blocks
> os.popen('/sbin/iptables -F INPUT')
> logFile.write(stamp), logFile.write('\n'), logFile.write('Flushing
> Rules..\n')
>
> ##Loop to read in file and Apply rules to IPtables
> for line in inFile.readlines():
> tmp = line.split(';')
> IP = tmp[0]
> outPut = os.popen( '/sbin/iptables -A INPUT -s' + ' ' + IP + ' ' + '-j
> REJECT' )
> logFile.write(IP), logFile.write(' - Has been blocked '),
> logFile.write(stamp),logFile.write
>
>
> The errors we're getting are like these:
>
> Bad argument `174.37.65.204'
> Try `iptables -h' or 'iptables --help' for more information.
> Bad argument `94.159.162.182'
> Try `iptables -h' or 'iptables --help' for more information.
> Bad argument `95.134.132.98'
> Try `iptables -h' or 'iptables --help' for more information.
> etc.
>
> Entries from the banlist.txt are like these:
>
> 200.193.54.138; February 9, 2013, 7:42 am <br>
> 87.120.57.4; February 9, 2013, 7:42 am <br>
> 82.206.129.160; February 9, 2013, 7:43 am <br>
> etc.
>
> I know the error points to a bad iptables command.
> Can someone tell me what change(s) I need to make to this script to get
> it working again? Thanks.
>
>
>
> --
> My email address on the header is a non-monitored spam catching account.
> I can be reached via http://www.wvnh.net/contact.htm
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From notreal at earthlink.net  Fri May 24 09:08:26 2013
From: notreal at earthlink.net (JackM)
Date: Fri, 24 May 2013 09:08:26 -0400
Subject: Read txt file, add to iptables not working on new host
In-Reply-To: <mailman.2048.1369365052.3114.python-list@python.org>
References: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>
	<mailman.2048.1369365052.3114.python-list@python.org>
Message-ID: <aDJnt.102617$zH4.33757@en-nntp-14.dc1.easynews.com>

Thanks for answering. Do you mean something like this?

outPut = os.popen('uname -a' '/sbin/iptables -V INPUT -s' + ' ' + IP + ' 
' + '-j  REJECT' )

Sorry but like I said, I have no experience with any of this.



On 5/23/2013 11:10 PM, Carlos Nepomuceno wrote:
> Send the output of the following commands:
>
> uname -a
> /sbin/iptables -V
>
>
> ----------------------------------------
>> From: notreal at earthlink.net
>> Subject: Read txt file, add to iptables not working on new host
>> Date: Thu, 23 May 2013 22:44:38 -0400
>> To: python-list at python.org
>>
>> First, let me say that I have no knowledge of or experience with Python
>> or Linux/Unix. I have a script which was written by a host tech person
>> that ran via cron on my old server. It was designed to read IP addresses
>> from a text file and add them to be blocked on iptables. That way, we
>> could add or remove IPs without involving tech support daily. It worked
>> great.
>>
>> Then we changed hosts and this script is now throwing errors on the new
>> server. This host runs Python 2.6.6. This is the script:
>>
>> #!/usr/bin/python
>> import os,time
>>
>> ##Input, Output, and TimeStamp
>> inFile = open('/var/www/html/mydomain.com/banlist.txt','r')
>> logFile = open('/var/log/banList.log','w')
>> stamp = time.asctime(time.localtime())
>>
>>
>> ##Daily Flush of blockList rules before re-applying Blocks
>> os.popen('/sbin/iptables -F INPUT')
>> logFile.write(stamp), logFile.write('\n'), logFile.write('Flushing
>> Rules..\n')
>>
>> ##Loop to read in file and Apply rules to IPtables
>> for line in inFile.readlines():
>> tmp = line.split(';')
>> IP = tmp[0]
>> outPut = os.popen( '/sbin/iptables -A INPUT -s' + ' ' + IP + ' ' + '-j
>> REJECT' )
>> logFile.write(IP), logFile.write(' - Has been blocked '),
>> logFile.write(stamp),logFile.write
>>
>>
>> The errors we're getting are like these:
>>
>> Bad argument `174.37.65.204'
>> Try `iptables -h' or 'iptables --help' for more information.
>> Bad argument `94.159.162.182'
>> Try `iptables -h' or 'iptables --help' for more information.
>> Bad argument `95.134.132.98'
>> Try `iptables -h' or 'iptables --help' for more information.
>> etc.
>>
>> Entries from the banlist.txt are like these:
>>
>> 200.193.54.138; February 9, 2013, 7:42 am <br>
>> 87.120.57.4; February 9, 2013, 7:42 am <br>
>> 82.206.129.160; February 9, 2013, 7:43 am <br>
>> etc.
>>
>> I know the error points to a bad iptables command.
>> Can someone tell me what change(s) I need to make to this script to get
>> it working again? Thanks.
>>
>>
>>
>> --
>> My email address on the header is a non-monitored spam catching account.
>> I can be reached via http://www.wvnh.net/contact.htm
>>
>> --
  		 	   		





From carlosnepomuceno at outlook.com  Fri May 24 09:15:45 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 24 May 2013 16:15:45 +0300
Subject: Read txt file, add to iptables not working on new host
In-Reply-To: <aDJnt.102617$zH4.33757@en-nntp-14.dc1.easynews.com>
References: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>,
	<mailman.2048.1369365052.3114.python-list@python.org>,
	<aDJnt.102617$zH4.33757@en-nntp-14.dc1.easynews.com>
Message-ID: <BLU176-W31AD0B0630120CBF80C30D7AB0@phx.gbl>

No, there's no need to change your python script, although it can be improved because as it is it may flush (delete all) iptables rules and let you vulnerable and don't create the new rules.

All you need to do is enter the commands in the shell and send it's output. The 'iptables' have changed.


----------------------------------------
> From: notreal at earthlink.net
> Subject: Re: Read txt file, add to iptables not working on new host
> Date: Fri, 24 May 2013 09:08:26 -0400
> To: python-list at python.org
>
> Thanks for answering. Do you mean something like this?
>
> outPut = os.popen('uname -a' '/sbin/iptables -V INPUT -s' + ' ' + IP + '
> ' + '-j REJECT' )
>
> Sorry but like I said, I have no experience with any of this.
>
>
>
> On 5/23/2013 11:10 PM, Carlos Nepomuceno wrote:
>> Send the output of the following commands:
>>
>> uname -a
>> /sbin/iptables -V
>>
>>
>> ----------------------------------------
>>> From: notreal at earthlink.net
>>> Subject: Read txt file, add to iptables not working on new host
>>> Date: Thu, 23 May 2013 22:44:38 -0400
>>> To: python-list at python.org
>>>
>>> First, let me say that I have no knowledge of or experience with Python
>>> or Linux/Unix. I have a script which was written by a host tech person
>>> that ran via cron on my old server. It was designed to read IP addresses
>>> from a text file and add them to be blocked on iptables. That way, we
>>> could add or remove IPs without involving tech support daily. It worked
>>> great.
>>>
>>> Then we changed hosts and this script is now throwing errors on the new
>>> server. This host runs Python 2.6.6. This is the script:
>>>
>>> #!/usr/bin/python
>>> import os,time
>>>
>>> ##Input, Output, and TimeStamp
>>> inFile = open('/var/www/html/mydomain.com/banlist.txt','r')
>>> logFile = open('/var/log/banList.log','w')
>>> stamp = time.asctime(time.localtime())
>>>
>>>
>>> ##Daily Flush of blockList rules before re-applying Blocks
>>> os.popen('/sbin/iptables -F INPUT')
>>> logFile.write(stamp), logFile.write('\n'), logFile.write('Flushing
>>> Rules..\n')
>>>
>>> ##Loop to read in file and Apply rules to IPtables
>>> for line in inFile.readlines():
>>> tmp = line.split(';')
>>> IP = tmp[0]
>>> outPut = os.popen( '/sbin/iptables -A INPUT -s' + ' ' + IP + ' ' + '-j
>>> REJECT' )
>>> logFile.write(IP), logFile.write(' - Has been blocked '),
>>> logFile.write(stamp),logFile.write
>>>
>>>
>>> The errors we're getting are like these:
>>>
>>> Bad argument `174.37.65.204'
>>> Try `iptables -h' or 'iptables --help' for more information.
>>> Bad argument `94.159.162.182'
>>> Try `iptables -h' or 'iptables --help' for more information.
>>> Bad argument `95.134.132.98'
>>> Try `iptables -h' or 'iptables --help' for more information.
>>> etc.
>>>
>>> Entries from the banlist.txt are like these:
>>>
>>> 200.193.54.138; February 9, 2013, 7:42 am <br>
>>> 87.120.57.4; February 9, 2013, 7:42 am <br>
>>> 82.206.129.160; February 9, 2013, 7:43 am <br>
>>> etc.
>>>
>>> I know the error points to a bad iptables command.
>>> Can someone tell me what change(s) I need to make to this script to get
>>> it working again? Thanks.
>>>
>>>
>>>
>>> --
>>> My email address on the header is a non-monitored spam catching account.
>>> I can be reached via http://www.wvnh.net/contact.htm
>>>
>>> --
>
>
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rosuav at gmail.com  Fri May 24 09:54:05 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 23:54:05 +1000
Subject: Read txt file, add to iptables not working on new host
In-Reply-To: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>
References: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>
Message-ID: <CAPTjJmozy2-WYzuGpezkr3FGY67-EQedxo=zet_uoZxkNKSB_Q@mail.gmail.com>

On Fri, May 24, 2013 at 12:44 PM, JackM <notreal at earthlink.net> wrote:
>         outPut = os.popen( '/sbin/iptables -A INPUT -s' + ' ' + IP + ' ' +
> '-j REJECT' )

There's so much about this script that's less than Pythonic, but the
one thing I'd really like to see is a log of the exact command being
executed. Replace the above line with this:

        command = '/sbin/iptables -A INPUT -s' + ' ' + IP + ' ' + '-j REJECT'
        outPut = os.popen(command)
        logFile.write(command+"\n")

That will show, in your log, exactly what's being executed. You should
then be able to execute that command in the shell and see the exact
same result. That might also show you the problem - it might be
obvious from the commands logged.

If that doesn't work, here's a rewrite of your code for cleanliness,
which still does what I think your original code does. See if they act
differently...

-- cut --

#!/usr/bin/python
import os
import time

# Input, Output, and TimeStamp
inFile = open('/var/www/html/mydomain.com/banlist.txt','r')
logFile = open('/var/log/banList.log','w')
stamp = time.asctime(time.localtime())

# Daily Flush of blockList rules before re-applying Blocks
os.popen('/sbin/iptables -F INPUT')
logFile.write(stamp+'\nFlushing Rules..\n')

# Loop to read in file and Apply rules to IPtables
for line in inFile:  # TODO: Use 'with' for a bit of protection
        ip = line.split(';')[0]
        output = os.popen( '/sbin/iptables -A INPUT -s ' + ip + ' -j REJECT' )
        logFile.write(IP+' - Has been blocked\n')


-- cut --

Since the timestamp doesn't change across a run anyway, there's not
much point printing it out every time, and I'm also putting newlines
in the logfile. Beyond that, it should function the same way as the
original.

ChrisA


From notreal at earthlink.net  Fri May 24 12:32:40 2013
From: notreal at earthlink.net (JackM)
Date: Fri, 24 May 2013 12:32:40 -0400
Subject: Read txt file, add to iptables not working on new host
In-Reply-To: <mailman.2067.1369403653.3114.python-list@python.org>
References: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>
	<mailman.2067.1369403653.3114.python-list@python.org>
Message-ID: <FCMnt.5938$4E1.5852@en-nntp-08.dc1.easynews.com>

So Chris, does this version look better? Changed to inFile to with.


#!/usr/bin/python
import os
import time

# Input, Output, and TimeStamp
logFile = open('/var/www/html/statistics/logs/banList.log','w')
stamp = time.asctime(time.localtime())

# Daily Flush of blockList rules before re-applying Blocks
os.popen('/sbin/iptables -F INPUT')
logFile.write(stamp+'\nFlushing Rules..\n')

# Loop to read in file and Apply rules to IPtables
with open('/var/www/html/mydomain.com/banlist.txt','r') as inFile:
	for line in inFile:  # TODO: Use 'with' for a bit of protection
         ip = line.split(';')[0]
         output = os.popen( '/sbin/iptables -A INPUT -s ' + ip + ' -j 
REJECT' )
		logFile.write(ip+' - Has been blocked\n')





On 5/24/2013 9:54 AM, Chris Angelico wrote:
> On Fri, May 24, 2013 at 12:44 PM, JackM <notreal at earthlink.net> wrote:
>>          outPut = os.popen( '/sbin/iptables -A INPUT -s' + ' ' + IP + ' ' +
>> '-j REJECT' )
>
> There's so much about this script that's less than Pythonic, but the
> one thing I'd really like to see is a log of the exact command being
> executed. Replace the above line with this:
>
>          command = '/sbin/iptables -A INPUT -s' + ' ' + IP + ' ' + '-j REJECT'
>          outPut = os.popen(command)
>          logFile.write(command+"\n")
>
> That will show, in your log, exactly what's being executed. You should
> then be able to execute that command in the shell and see the exact
> same result. That might also show you the problem - it might be
> obvious from the commands logged.
>
> If that doesn't work, here's a rewrite of your code for cleanliness,
> which still does what I think your original code does. See if they act
> differently...
>
> -- cut --
>
> #!/usr/bin/python
> import os
> import time
>
> # Input, Output, and TimeStamp
> inFile = open('/var/www/html/mydomain.com/banlist.txt','r')
> logFile = open('/var/log/banList.log','w')
> stamp = time.asctime(time.localtime())
>
> # Daily Flush of blockList rules before re-applying Blocks
> os.popen('/sbin/iptables -F INPUT')
> logFile.write(stamp+'\nFlushing Rules..\n')
>
> # Loop to read in file and Apply rules to IPtables
> for line in inFile:  # TODO: Use 'with' for a bit of protection
>          ip = line.split(';')[0]
>          output = os.popen( '/sbin/iptables -A INPUT -s ' + ip + ' -j REJECT' )
>          logFile.write(IP+' - Has been blocked\n')
>
>
> -- cut --
>
> Since the timestamp doesn't change across a run anyway, there's not
> much point printing it out every time, and I'm also putting newlines
> in the logfile. Beyond that, it should function the same way as the
> original.
>
> ChrisA
>


-- 
My email address on the header is a non-monitored spam catching account. 
I can be reached via http://www.wvnh.net/contact.htm



From rosuav at gmail.com  Fri May 24 12:56:47 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 02:56:47 +1000
Subject: Read txt file, add to iptables not working on new host
In-Reply-To: <FCMnt.5938$4E1.5852@en-nntp-08.dc1.easynews.com>
References: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>
	<mailman.2067.1369403653.3114.python-list@python.org>
	<FCMnt.5938$4E1.5852@en-nntp-08.dc1.easynews.com>
Message-ID: <CAPTjJmran-gqXgQMwKtjbbOvC7gx2QZkMWWuXTXkG4FeVx-zgg@mail.gmail.com>

On Sat, May 25, 2013 at 2:32 AM, JackM <notreal at earthlink.net> wrote:
> So Chris, does this version look better? Changed to inFile to with.
>

Heh, I didn't know you knew about with :) Since you know how to use
it, you probably also know why it's useful. Anyway, the main thing is
to see the exact command that's being executed, which you then should
be able to try at a shell prompt.

ChrisA


From davea at davea.name  Fri May 24 15:29:27 2013
From: davea at davea.name (Dave Angel)
Date: Fri, 24 May 2013 15:29:27 -0400
Subject: Read txt file, add to iptables not working on new host
In-Reply-To: <FCMnt.5938$4E1.5852@en-nntp-08.dc1.easynews.com>
References: <puAnt.800936$OJ2.639894@en-nntp-11.dc1.easynews.com>
	<mailman.2067.1369403653.3114.python-list@python.org>
	<FCMnt.5938$4E1.5852@en-nntp-08.dc1.easynews.com>
Message-ID: <519FBF97.3050504@davea.name>

On 05/24/2013 12:32 PM, JackM wrote:
> So Chris, does this version look better? Changed to inFile to with.
>
>
> #!/usr/bin/python
> import os
> import time
>
> # Input, Output, and TimeStamp
> logFile = open('/var/www/html/statistics/logs/banList.log','w')
> stamp = time.asctime(time.localtime())
>
> # Daily Flush of blockList rules before re-applying Blocks
> os.popen('/sbin/iptables -F INPUT')
> logFile.write(stamp+'\nFlushing Rules..\n')
>
> # Loop to read in file and Apply rules to IPtables
> with open('/var/www/html/mydomain.com/banlist.txt','r') as inFile:
>      for line in inFile:  # TODO: Use 'with' for a bit of protection
>          ip = line.split(';')[0]

You want to write the command to the logfile here, BEFORE you try the 
popen().  That way if there's a problem, you can see what it was about 
to try before it crashed.

>          output = os.popen( '/sbin/iptables -A INPUT -s ' + ip + ' -j
> REJECT' )
>          logFile.write(ip+' - Has been blocked\n')
>
>
>
>

-- 
DaveA


From lokeshkoppaka at gmail.com  Fri May 24 04:04:51 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Fri, 24 May 2013 01:04:51 -0700 (PDT)
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
Message-ID: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>

i need to write a code which can sort the list in order of 'n' without use builtin functions 
can anyone help me how to do?


From rosuav at gmail.com  Fri May 24 04:12:45 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 18:12:45 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
Message-ID: <CAPTjJmrBHYGhG0yLNR_dvMb4kR6uGUfK0z2kyAh7Rafn24PxMw@mail.gmail.com>

On Fri, May 24, 2013 at 6:04 PM,  <lokeshkoppaka at gmail.com> wrote:
> i need to write a code which can sort the list in order of 'n' without use builtin functions
> can anyone help me how to do?
> --
> http://mail.python.org/mailman/listinfo/python-list

http://lmgtfy.com/?q=sorting+algorithm
http://www.catb.org/esr/faqs/smart-questions.html

ChrisA


From davea at davea.name  Fri May 24 08:33:57 2013
From: davea at davea.name (Dave Angel)
Date: Fri, 24 May 2013 08:33:57 -0400
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
Message-ID: <519F5E35.8030107@davea.name>

On 05/24/2013 04:04 AM, lokeshkoppaka at gmail.com wrote:
> i need to write a code which can sort the list in order of 'n' without use builtin functions
> can anyone help me how to do?
>

You could sort, but you couldn't print out the results, so what's the 
point?  In Python 3.3 at least, print() is a built-in function.

Is the homework assignment more clearly worded than your summary?  And 
if so, how far have you gotten on it?

-- 
DaveA


From carlosnepomuceno at outlook.com  Fri May 24 09:06:59 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 24 May 2013 16:06:59 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
Message-ID: <BLU176-W6937132B5DA30CA5C813FD7AB0@phx.gbl>

lol wtf?

If 'n' is the quantity of elements to be sorted there's 
no way you can write an algorithm with complexity O(n) for the worst 
case not knowing something special about the data.

For example, Quicksort will give you O(n*(log(n)) on average case (O(n^2) in the worst case).

You gotta be much more specific than that if you really need an O(n) code.

There's probably assumptions you didn't mention about the data if O(n) it's really what you're looking for.

PS: Looks like a joke as stated..

----------------------------------------
> Date: Fri, 24 May 2013 01:04:51 -0700
> Subject: help how to sort a list in order of 'n' in python without using inbuilt functions??
> From: lokeshkoppaka at gmail.com
> To: python-list at python.org
>
> i need to write a code which can sort the list in order of 'n' without use builtin functions
> can anyone help me how to do?
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From lokeshkoppaka at gmail.com  Sat May 25 01:15:21 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Fri, 24 May 2013 22:15:21 -0700 (PDT)
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
Message-ID: <78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>

On Friday, May 24, 2013 1:34:51 PM UTC+5:30, lokesh... at gmail.com wrote:
> i need to write a code which can sort the list in order of 'n' without use builtin functions 
> 
> can anyone help me how to do?

 Note:
the list only contains 0's,1's,2's
need to sort them in order of 'n'


From rosuav at gmail.com  Sat May 25 01:24:01 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 15:24:01 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
Message-ID: <CAPTjJmoFUOaDarhzy0c_mVCLLgRTS67jk0hhW4PXyxCkfKb-vA@mail.gmail.com>

On Sat, May 25, 2013 at 3:15 PM,  <lokeshkoppaka at gmail.com> wrote:
> On Friday, May 24, 2013 1:34:51 PM UTC+5:30, lokesh... at gmail.com wrote:
>> i need to write a code which can sort the list in order of 'n' without use builtin functions
>>
>> can anyone help me how to do?
>
>  Note:
> the list only contains 0's,1's,2's
> need to sort them in order of 'n'

In that case, you're not really ordering them, you're counting them.
Look at the collections module; you can very easily figure out how
many of each there are, and then reconstruct the list afterward.

ChrisA


From lokeshkoppaka at gmail.com  Sat May 25 01:39:06 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Fri, 24 May 2013 22:39:06 -0700 (PDT)
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <mailman.2109.1369459444.3114.python-list@python.org>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
Message-ID: <39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>

On Saturday, May 25, 2013 10:54:01 AM UTC+5:30, Chris Angelico wrote:
> On Sat, May 25, 2013 at 3:15 PM,  <lokeshkoppaka at gmail.com> wrote:
> 
> > On Friday, May 24, 2013 1:34:51 PM UTC+5:30, lokesh... at gmail.com wrote:
> 
> >> i need to write a code which can sort the list in order of 'n' without use builtin functions
> 
> >>
> 
> >> can anyone help me how to do?
> 
> >
> 
> >  Note:
> 
> > the list only contains 0's,1's,2's
> 
> > need to sort them in order of 'n'
> 
> 
> 
> In that case, you're not really ordering them, you're counting them.
> 
> Look at the collections module; you can very easily figure out how
> 
> many of each there are, and then reconstruct the list afterward.
> 
> 
> 
> ChrisA

but i need to do it with out using builtin functions


From rosuav at gmail.com  Sat May 25 01:43:30 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 15:43:30 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
Message-ID: <CAPTjJmpcJAdpouYm2yhF362Oyy8v5Dbuq=U93RDwKowQLPn0Qw@mail.gmail.com>

On Sat, May 25, 2013 at 3:39 PM,  <lokeshkoppaka at gmail.com> wrote:
> On Saturday, May 25, 2013 10:54:01 AM UTC+5:30, Chris Angelico wrote:
>> On Sat, May 25, 2013 at 3:15 PM,  <lokeshkoppaka at gmail.com> wrote:
>>
>> > On Friday, May 24, 2013 1:34:51 PM UTC+5:30, lokesh... at gmail.com wrote:
>>
>> >> i need to write a code which can sort the list in order of 'n' without use builtin functions
>>
>> >>
>>
>> >> can anyone help me how to do?
>>
>> >
>>
>> >  Note:
>>
>> > the list only contains 0's,1's,2's
>>
>> > need to sort them in order of 'n'
>>
>>
>>
>> In that case, you're not really ordering them, you're counting them.
>>
>> Look at the collections module; you can very easily figure out how
>>
>> many of each there are, and then reconstruct the list afterward.
>>
>>
>>
>> ChrisA
>
> but i need to do it with out using builtin functions

Depending on your definitions, that's either trivially easy (the
'collections' module is not builtin functions) or completely
impossible. Have fun.

ChrisA


From steve+comp.lang.python at pearwood.info  Sat May 25 01:57:38 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 25 May 2013 05:57:38 GMT
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
Message-ID: <51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>

On Fri, 24 May 2013 22:39:06 -0700, lokeshkoppaka wrote:

> On Saturday, May 25, 2013 10:54:01 AM UTC+5:30, Chris Angelico wrote:

>> In that case, you're not really ordering them, you're counting them.
>> Look at the collections module; you can very easily figure out how
>> many of each there are, and then reconstruct the list afterward.
> 
> but i need to do it with out using builtin functions


How would you, an intelligent human being count them?

Describe how you would count them in English, or whatever your native 
language is.

"First I would start a tally for the number of zeroes, tally = 0. Then I 
look at each item in turn, and if it is 0, I add one to the tally. When I 
get to the end, I the number of zeroes is equal to the tally.

Then I do the same for the number of ones, and the number of twos."

Now turn that into Python code. 

tally = 0
for item in list_of_items:
    if item == 0:
        tally = tally + 1

print "The number of zeroes equals", tally



-- 
Steven


From lokeshkoppaka at gmail.com  Sat May 25 02:05:17 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Fri, 24 May 2013 23:05:17 -0700 (PDT)
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>

On Saturday, May 25, 2013 11:27:38 AM UTC+5:30, Steven D'Aprano wrote:
> On Fri, 24 May 2013 22:39:06 -0700, lokeshkoppaka wrote:
> 
> 
> 
> > On Saturday, May 25, 2013 10:54:01 AM UTC+5:30, Chris Angelico wrote:
> 
> 
> 
> >> In that case, you're not really ordering them, you're counting them.
> 
> >> Look at the collections module; you can very easily figure out how
> 
> >> many of each there are, and then reconstruct the list afterward.
> 
> > 
> 
> > but i need to do it with out using builtin functions
> 
> 
> 
> 
> 
> How would you, an intelligent human being count them?
> 
> 
> 
> Describe how you would count them in English, or whatever your native 
> 
> language is.
> 
> 
> 
> "First I would start a tally for the number of zeroes, tally = 0. Then I 
> 
> look at each item in turn, and if it is 0, I add one to the tally. When I 
> 
> get to the end, I the number of zeroes is equal to the tally.
> 
> 
> 
> Then I do the same for the number of ones, and the number of twos."
> 
> 
> 
> Now turn that into Python code. 
> 
> 
> 
> tally = 0
> 
> for item in list_of_items:
> 
>     if item == 0:
> 
>         tally = tally + 1
> 
> 
> 
> print "The number of zeroes equals", tally
> 
> 
> 
> 
> 
> 
> 
> -- 
> 
> Steven

ya steven i had done the similar logic but thats not satisfying my professor 
he had given the following constrains
 1. No in-built functions should be used
 2. we are expecting a O(n) solution
 3. Don't use count method


From rosuav at gmail.com  Sat May 25 02:12:24 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 16:12:24 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
Message-ID: <CAPTjJmrT4sQKZjaxawxGbhioBEgtw8YBsZBxBHdMdyWmWO0Byw@mail.gmail.com>

On Sat, May 25, 2013 at 4:05 PM,  <lokeshkoppaka at gmail.com> wrote:
> ya steven i had done the similar logic but thats not satisfying my professor
> he had given the following constrains
>  1. No in-built functions should be used
>  2. we are expecting a O(n) solution
>  3. Don't use count method

And now you finally admit that it's homework.

Solve it yourself, or go to your prof and say that you need help.

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 03:53:19 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 10:53:19 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
Message-ID: <BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>

----------------------------------------
> Date: Fri, 24 May 2013 23:05:17 -0700
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> From: lokeshkoppaka at gmail.com
> To: python-list at python.org
[...]
> ya steven i had done the similar logic but thats not satisfying my professor
> he had given the following constrains
> 1. No in-built functions should be used
> 2. we are expecting a O(n) solution
> 3. Don't use count method

That's trivial!

# l is a list of numbers: 0,1,2
def order_n(l):
??? r = []
??? count = [0]*3
??? count[2] = len(l)
??? for i in range(len(l)):
??????? count[1] += abs((l[i]>0)-1)
??????? r.insert(count[l[i]], l[i])
??? return r

'count' is a list I've defined to count the quantity of the elements in the argument, not the method.

I don't think it needs any explanations, but if you have any doubts just ask. ;)

Good luck! 		 	   		  

From rosuav at gmail.com  Sat May 25 04:28:32 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 18:28:32 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
Message-ID: <CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>

On Sat, May 25, 2013 at 5:53 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> ----------------------------------------
>> Date: Fri, 24 May 2013 23:05:17 -0700
>> 1. No in-built functions should be used
>     count[2] = len(l)

Fail! :)

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 04:43:55 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 11:43:55 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>,
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>,
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
Message-ID: <BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>

----------------------------------------
> Date: Sat, 25 May 2013 18:28:32 +1000
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> From: rosuav at gmail.com
> To: python-list at python.org
>
> On Sat, May 25, 2013 at 5:53 PM, Carlos Nepomuceno
> <carlosnepomuceno at outlook.com> wrote:
>> ----------------------------------------
>>> Date: Fri, 24 May 2013 23:05:17 -0700
>>> 1. No in-built functions should be used
>> count[2] = len(l)
>
> Fail! :)
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list

lol I forgot to include this monkey patch! ;)

def length(l):
??? x=0
??? y=l[:]
??? while y:
??????? x+=1
??????? y.pop()
??? return x 		 	   		  

From rosuav at gmail.com  Sat May 25 04:47:24 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 18:47:24 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
Message-ID: <CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>

On Sat, May 25, 2013 at 6:43 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> ----------------------------------------
> lol I forgot to include this monkey patch! ;)
>
> def length(l):
>     x=0
>     y=l[:]
>     while y:
>         x+=1
>         y.pop()
>     return x

Nice. Now eliminate abs (easy) and range. :)

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 04:54:53 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 11:54:53 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>,
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>,
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>,
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>,
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
Message-ID: <BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>

lol

def absolute(x):
??? return x if x>0 else -x

def reach(x):
??? y=[]
??? z=0
??? while z<x:
??????? y.append(z)
??????? z+=1
??? return y

----------------------------------------
> Date: Sat, 25 May 2013 18:47:24 +1000
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> From: rosuav at gmail.com
> To: python-list at python.org
>
> On Sat, May 25, 2013 at 6:43 PM, Carlos Nepomuceno
> <carlosnepomuceno at outlook.com> wrote:
>> ----------------------------------------
>> lol I forgot to include this monkey patch! ;)
>>
>> def length(l):
>> x=0
>> y=l[:]
>> while y:
>> x+=1
>> y.pop()
>> return x
>
> Nice. Now eliminate abs (easy) and range. :)
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rosuav at gmail.com  Sat May 25 05:01:09 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 19:01:09 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
Message-ID: <CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>

On Sat, May 25, 2013 at 6:54 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> lol
>
> def absolute(x):
>     return x if x>0 else -x
>
> def reach(x):
>     y=[]
>     z=0
>     while z<x:
>         y.append(z)
>         z+=1
>     return y

Very good. You are now in a position to get past the limitations of a
restricted-environment eval/exec. Avoiding builtins is actually a fun
skill to hone.

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 05:10:06 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 12:10:06 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>,
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>,
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>,
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>,
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>,
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>,
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
Message-ID: <BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>

----------------------------------------
> Date: Sat, 25 May 2013 19:01:09 +1000
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> From: rosuav at gmail.com
> To: python-list at python.org
[...]
> Very good. You are now in a position to get past the limitations of a
> restricted-environment eval/exec. Avoiding builtins is actually a fun
> skill to hone.
>
> ChrisA


I'm glad he didn't ask for a Pseudo-RNG without built-ins! ;) 		 	   		  

From rosuav at gmail.com  Sat May 25 05:14:57 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 19:14:57 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
Message-ID: <CAPTjJmo8eoXOm7ifGAxa4h_4qRCqU4MHd2yFQHNA54ti9tskxQ@mail.gmail.com>

On Sat, May 25, 2013 at 7:10 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> ----------------------------------------
>> Date: Sat, 25 May 2013 19:01:09 +1000
>> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
>> From: rosuav at gmail.com
>> To: python-list at python.org
> [...]
>> Very good. You are now in a position to get past the limitations of a
>> restricted-environment eval/exec. Avoiding builtins is actually a fun
>> skill to hone.
>>
>> ChrisA
>
>
> I'm glad he didn't ask for a Pseudo-RNG without built-ins! ;)

def random_number():
    return 7

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 05:30:28 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 12:30:28 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <CAPTjJmo8eoXOm7ifGAxa4h_4qRCqU4MHd2yFQHNA54ti9tskxQ@mail.gmail.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>,
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>,
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>,
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>,
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>,
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>,
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>,
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>,
	<CAPTjJmo8eoXOm7ifGAxa4h_4qRCqU4MHd2yFQHNA54ti9tskxQ@mail.gmail.com>
Message-ID: <BLU176-W2A608FB292D64077F7B47D7940@phx.gbl>

lol http://search.dilbert.com/comic/Random%20Nine

----------------------------------------
> Date: Sat, 25 May 2013 19:14:57 +1000
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> From: rosuav at gmail.com
> To: python-list at python.org
>
> On Sat, May 25, 2013 at 7:10 PM, Carlos Nepomuceno
> <carlosnepomuceno at outlook.com> wrote:
>> ----------------------------------------
>>> Date: Sat, 25 May 2013 19:01:09 +1000
>>> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
>>> From: rosuav at gmail.com
>>> To: python-list at python.org
>> [...]
>>> Very good. You are now in a position to get past the limitations of a
>>> restricted-environment eval/exec. Avoiding builtins is actually a fun
>>> skill to hone.
>>>
>>> ChrisA
>>
>>
>> I'm glad he didn't ask for a Pseudo-RNG without built-ins! ;)
>
> def random_number():
> return 7
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From steve+comp.lang.python at pearwood.info  Sat May 25 10:28:33 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 25 May 2013 14:28:33 GMT
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
Message-ID: <51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Sat, 25 May 2013 19:14:57 +1000, Chris Angelico wrote:

> def random_number():
>     return 7

I call shenanigans! That value isn't generated randomly, you just made it 
up! I rolled a die *hundreds* of times and not once did it come up seven!



-- 
Steven


From fabiosantosart at gmail.com  Sat May 25 10:46:46 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sat, 25 May 2013 15:46:46 +0100
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAA=1kxQj2bVNRoGSQ_fKc1Pf8g1azU3ASRHXDneT5J5Dv6wueQ@mail.gmail.com>

On 25 May 2013 15:35, "Steven D'Aprano" <
steve+comp.lang.python at pearwood.info> wrote:
>
> On Sat, 25 May 2013 19:14:57 +1000, Chris Angelico wrote:
>
> > def random_number():
> >     return 7
>
> I call shenanigans! That value isn't generated randomly, you just made it
> up! I rolled a die *hundreds* of times and not once did it come up seven!
>
>
>
> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list

Try flipping a coin. I flipped one a couple of times and got the seventh
face once.
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From breamoreboy at yahoo.co.uk  Sat May 25 11:03:44 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 25 May 2013 16:03:44 +0100
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <knqjrp$nep$1@ger.gmane.org>

On 25/05/2013 15:28, Steven D'Aprano wrote:
> On Sat, 25 May 2013 19:14:57 +1000, Chris Angelico wrote:
>
>> def random_number():
>>      return 7
>
> I call shenanigans! That value isn't generated randomly, you just made it
> up! I rolled a die *hundreds* of times and not once did it come up seven!
>
>
>

Lies, damn lies and statistics? :)

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From rosuav at gmail.com  Sat May 25 11:41:58 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 01:41:58 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmpWeG3xRqKSXuH1+SwLTJhi-S=USU8cmXaQHFmgib=iyw@mail.gmail.com>

On Sun, May 26, 2013 at 12:28 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Sat, 25 May 2013 19:14:57 +1000, Chris Angelico wrote:
>
>> def random_number():
>>     return 7
>
> I call shenanigans! That value isn't generated randomly, you just made it
> up! I rolled a die *hundreds* of times and not once did it come up seven!

You've obviously never used a REAL set of dice. Now, I have here with
me a set used for maths drill (to be entirely accurate, what I have
here is the company's stock of them, so there are multiples of each of
these - anyone need to buy dice?) with everything except the classic 1
through 6 that everyone knows:

* Six sides, faces marked 7 through 12
* Six sides, faces marked "+x-\xf7+" and a "wild" marker (yes, two of +)
* Ten sides, numbered 0 through 9
* Eight sides, numbered 1 through 8
* Twelve sides, as above
* Twenty sides, as above

Now, tabletop roleplayers will recognize the latter four as the ones
notated as d10, d8, d12, and d20, but these are NOT for gameplay, they
are for serious educational purposes! Honest!

Anyway, all of those can roll a 7... well, one of them has to roll a
\xf7, but close enough right? Plus, if you roll 2d6 (that is, two
regular six-sided dice and add them up), 7 is statistically the most
likely number to come up with. Therefore it IS random.

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 13:17:51 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 20:17:51 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <CAPTjJmpWeG3xRqKSXuH1+SwLTJhi-S=USU8cmXaQHFmgib=iyw@mail.gmail.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>,
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>,
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>,
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>,
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>,
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>,
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>,
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>,
	<mailman.2127.1369473306.3114.python-list@python.org>,
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<CAPTjJmpWeG3xRqKSXuH1+SwLTJhi-S=USU8cmXaQHFmgib=iyw@mail.gmail.com>
Message-ID: <BLU176-W420C2B916435EE6F327BF6D7940@phx.gbl>

----------------------------------------
> Date: Sun, 26 May 2013 01:41:58 +1000
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> From: rosuav at gmail.com
> To: python-list at python.org
>
> On Sun, May 26, 2013 at 12:28 AM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> On Sat, 25 May 2013 19:14:57 +1000, Chris Angelico wrote:
>>
>>> def random_number():
>>> return 7
>>
>> I call shenanigans! That value isn't generated randomly, you just made it
>> up! I rolled a die *hundreds* of times and not once did it come up seven!
>
> You've obviously never used a REAL set of dice. Now, I have here with
> me a set used for maths drill (to be entirely accurate, what I have
> here is the company's stock of them, so there are multiples of each of
> these - anyone need to buy dice?) with everything except the classic 1
> through 6 that everyone knows:
>
> * Six sides, faces marked 7 through 12
> * Six sides, faces marked "+x-\xf7+" and a "wild" marker (yes, two of +)
> * Ten sides, numbered 0 through 9
> * Eight sides, numbered 1 through 8
> * Twelve sides, as above
> * Twenty sides, as above
>
> Now, tabletop roleplayers will recognize the latter four as the ones
> notated as d10, d8, d12, and d20, but these are NOT for gameplay, they
> are for serious educational purposes! Honest!
>
> Anyway, all of those can roll a 7... well, one of them has to roll a
> \xf7, but close enough right? Plus, if you roll 2d6 (that is, two
> regular six-sided dice and add them up), 7 is statistically the most
> likely number to come up with. Therefore it IS random.
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list


def f(x):
??? return x+1

or you can just go:

f(roll_d6())

;) 		 	   		  

From rosuav at gmail.com  Sat May 25 13:23:44 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 03:23:44 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <BLU176-W420C2B916435EE6F327BF6D7940@phx.gbl>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmpWeG3xRqKSXuH1+SwLTJhi-S=USU8cmXaQHFmgib=iyw@mail.gmail.com>
	<BLU176-W420C2B916435EE6F327BF6D7940@phx.gbl>
Message-ID: <CAPTjJmoRfFCkS34aoro1JVD1U5sCw6X7Z5Rx_o4juuhBMHnkdw@mail.gmail.com>

On Sun, May 26, 2013 at 3:17 AM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> def f(x):
>     return x+1
>
> or you can just go:
>
> f(roll_d6())

Hmm. Interesting. So now we have a question: Does adding 1 to a random
number make it less random? It adds determinism to the number; can a
number be more deterministic while still no less random?

Ah! I know. The answer comes from common sense:

a = random()   # a is definitely a random number
a -= random()  # a is no longer random, we subtracted all the randomness from it

Of course, since number-number => number, a is still a number. And so
we can conclude that adding 1 to a random dice roll does indeed leave
all the randomness still in it. But wait! That means we can do
better!!

a = random()   # a is a random number
a *= 5   # a is clearly five times as random now!

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 13:34:02 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 20:34:02 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <CAPTjJmoRfFCkS34aoro1JVD1U5sCw6X7Z5Rx_o4juuhBMHnkdw@mail.gmail.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>,
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>,
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>,
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>,
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>,
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>,
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>,
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>,
	<mailman.2127.1369473306.3114.python-list@python.org>,
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<CAPTjJmpWeG3xRqKSXuH1+SwLTJhi-S=USU8cmXaQHFmgib=iyw@mail.gmail.com>,
	<BLU176-W420C2B916435EE6F327BF6D7940@phx.gbl>,
	<CAPTjJmoRfFCkS34aoro1JVD1U5sCw6X7Z5Rx_o4juuhBMHnkdw
	@mail.gmail.com>
Message-ID: <BLU176-W25404AAFDCBB88594BB605D7940@phx.gbl>

----------------------------------------
> Date: Sun, 26 May 2013 03:23:44 +1000
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> From: rosuav at gmail.com
> To: python-list at python.org
>
> On Sun, May 26, 2013 at 3:17 AM, Carlos Nepomuceno
> <carlosnepomuceno at outlook.com> wrote:
>> def f(x):
>> return x+1
>>
>> or you can just go:
>>
>> f(roll_d6())
>
> Hmm. Interesting. So now we have a question: Does adding 1 to a random
> number make it less random? It adds determinism to the number; can a
> number be more deterministic while still no less random?
>
> Ah! I know. The answer comes from common sense:
>
> a = random() # a is definitely a random number
> a -= random() # a is no longer random, we subtracted all the randomness from it
>
> Of course, since number-number => number, a is still a number. And so
> we can conclude that adding 1 to a random dice roll does indeed leave
> all the randomness still in it. But wait! That means we can do
> better!!
>
> a = random() # a is a random number
> a *= 5 # a is clearly five times as random now!
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list

It depends if the result (any operation) is in the required range.

For example: "int(random.random()+1)" it's not random at all!

But "int(random.random()*1000)" my look random if it fits your needs.

;) 		 	   		  

From steve+comp.lang.python at pearwood.info  Sat May 25 23:38:12 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 26 May 2013 03:38:12 GMT
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmpWeG3xRqKSXuH1+SwLTJhi-S=USU8cmXaQHFmgib=iyw@mail.gmail.com>
	<BLU176-W420C2B916435EE6F327BF6D7940@phx.gbl>
	<mailman.2142.1369502632.3114.python-list@python.org>
Message-ID: <51a183a4$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Sun, 26 May 2013 03:23:44 +1000, Chris Angelico wrote:

> Does adding 1 to a random
> number make it less random? It adds determinism to the number; can a
> number be more deterministic while still no less random?
> 
> Ah! I know. The answer comes from common sense:
[snip spurious answer]

I know you're being funny, but in fact adding a constant to a random 
variable still leaves it equally random. Adding, multiplying, dividing or 
subtracting a constant from a random variable X just shifts the possible 
values X can take, it doesn't change the shape of the distribution. 
However, adding two random variables X and Y does change the 
distribution. In fact, a very cheap way of simulating an almost normally 
distributed random variable is to add up a whole lot of uniformly 
distributed random variables. Adding up 12 calls to random.random(), and 
subtracting 6, gives you a close approximation to a Gaussian random 
variable with mean 0 and standard deviation 1.



-- 
Steven


From dan at tombstonezero.net  Sun May 26 00:06:34 2013
From: dan at tombstonezero.net (Dan Sommers)
Date: Sun, 26 May 2013 04:06:34 GMT
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmpWeG3xRqKSXuH1+SwLTJhi-S=USU8cmXaQHFmgib=iyw@mail.gmail.com>
	<BLU176-W420C2B916435EE6F327BF6D7940@phx.gbl>
	<mailman.2142.1369502632.3114.python-list@python.org>
	<51a183a4$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <eTfot.4451$EM6.288@newsfe04.iad>

On Sun, 26 May 2013 03:38:12 +0000, Steven D'Aprano wrote:

> ... adding a constant to a random variable still leaves it equally
> random. Adding, multiplying, dividing or subtracting a constant from a
> random variable X just shifts the possible values X can take ...

That's mathematically true, but this is the Python mailing list.

Adding, subtracting, or dividing by a sufficiently large constant loses
all the randomness.

Python 3.2.4 (default, May  8 2013, 20:55:18) 
[GCC 4.7.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import random
>>> random.random() + 1e200
1e+200
>>> random.random() - 1e200
-1e+200
>>> random.random() / 1e309
0.0

But you knew that.  ;-)

Dan


From rosuav at gmail.com  Sun May 26 00:28:37 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 14:28:37 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <51a183a4$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<CAPTjJmpWeG3xRqKSXuH1+SwLTJhi-S=USU8cmXaQHFmgib=iyw@mail.gmail.com>
	<BLU176-W420C2B916435EE6F327BF6D7940@phx.gbl>
	<mailman.2142.1369502632.3114.python-list@python.org>
	<51a183a4$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmrTSDftuttBKhDz8f6GpbMWLZQ+X1JrKCKj6XKUe=0G4A@mail.gmail.com>

On Sun, May 26, 2013 at 1:38 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Sun, 26 May 2013 03:23:44 +1000, Chris Angelico wrote:
>
>> Does adding 1 to a random
>> number make it less random? It adds determinism to the number; can a
>> number be more deterministic while still no less random?
>>
>> Ah! I know. The answer comes from common sense:
> [snip spurious answer]
>
> I know you're being funny, but in fact adding a constant to a random
> variable still leaves it equally random. Adding, multiplying, dividing or
> subtracting a constant from a random variable X just shifts the possible
> values X can take, it doesn't change the shape of the distribution.

In real numbers, that's correct. However, computers don't work with
real numbers, so there's the very, uhh, REAL possibility that some of
the entropy will be lost. For instance, multiplying and dividing when
working with integers results in truncation, and adding huge numbers
to small floats results in precision loss.

I was deliberately playing around, but unfortunately there have been
many people who've genuinely thought things similar to what I was
saying - and then implemented into code.

> However, adding two random variables X and Y does change the
> distribution. In fact, a very cheap way of simulating an almost normally
> distributed random variable is to add up a whole lot of uniformly
> distributed random variables. Adding up 12 calls to random.random(), and
> subtracting 6, gives you a close approximation to a Gaussian random
> variable with mean 0 and standard deviation 1.

Yep. The more dice you roll, the more normal the distribution. Which
means that d100 is extremely swingy, but 11d10-10 is much less so, and
99d2-98 quite stable. The more randomness you add, the more
predictable the result.

<quote source="Jubal Early">Does that seem right to you?</quote>

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 13:12:44 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 20:12:44 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>,
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>,
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>,
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>,
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>,
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>,
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>,
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>,
	<mailman.2127.1369473306.3114.python-list@python.org>,
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <BLU176-W2007B3DEE8504DC9E9391AD7940@phx.gbl>

----------------------------------------
> From: steve+comp.lang.python at pearwood.info
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> Date: Sat, 25 May 2013 14:28:33 +0000
> To: python-list at python.org
>
> On Sat, 25 May 2013 19:14:57 +1000, Chris Angelico wrote:
>
>> def random_number():
>> return 7
>
> I call shenanigans! That value isn't generated randomly, you just made it
> up! I rolled a die *hundreds* of times and not once did it come up seven!


lol It worked fine on my d8! lol 		 	   		  

From steve+comp.lang.python at pearwood.info  Sat May 25 23:09:51 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 26 May 2013 03:09:51 GMT
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2137.1369496527.3114.python-list@python.org>
Message-ID: <51a17cff$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Sun, 26 May 2013 01:41:58 +1000, Chris Angelico wrote:

> On Sun, May 26, 2013 at 12:28 AM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> On Sat, 25 May 2013 19:14:57 +1000, Chris Angelico wrote:
>>
>>> def random_number():
>>>     return 7
>>
>> I call shenanigans! That value isn't generated randomly, you just made
>> it up! I rolled a die *hundreds* of times and not once did it come up
>> seven!
> 
> You've obviously never used a REAL set of dice.

You're right, all my dice are eight-sided and complex:

1+0i
1+1i
1-1i
-1+0i
-1+1i
-1-1i


:-)


But seriously, I have various D&D style gaming dice, d4, d6, d8, d12, d20 
and d30. But I thought the opportunity for a joke was more important than 
pedantic correctness :-)


> Now, I have here with me
> a set used for maths drill (to be entirely accurate, what I have here is
> the company's stock of them, so there are multiples of each of these -
> anyone need to buy dice?) 

Are you serious? What's the cost, posted to Melbourne?


> with everything except the classic 1 through 6 that everyone knows:
> 
> * Six sides, faces marked 7 through 12 
> * Six sides, faces marked "+x-\xf7+" and a "wild" marker 
>   (yes, two of +)

Oh, you mean ? (division sign)! Why didn't you say so? :-P

And another thing, shame on you, you mean ? not x. It's easy to find too:

py> from unicodedata import lookup
py> print(lookup("MULTIPLICATION SIGN"))
?


> * Ten sides, numbered 0 through 9
> * Eight sides, numbered 1 through 8
> * Twelve sides, as above
> * Twenty sides, as above
> 
> Now, tabletop roleplayers will recognize the latter four as the ones
> notated as d10, d8, d12, and d20, but these are NOT for gameplay, they
> are for serious educational purposes! Honest!
> 
> Anyway, all of those can roll a 7... well, one of them has to roll a
> \xf7, but close enough right? 

I don't think so...

> Plus, if you roll 2d6 (that is, two
> regular six-sided dice and add them up), 7 is statistically the most
> likely number to come up with. Therefore it IS random.

Yes, but if you subtract them the most common is 0, if you multiply the 
most common are 6 or 12, and if you divide the most common is 1. If you 
decide on the operation randomly, using the +-??+ die above (ignoring 
wildcards), the most common result is 6. The probability of getting a 7 
is just 1/15.

from collections import Counter
from operator import add, sub, mul, truediv as div
ops = (add, sub, mul, div, add)
Counter(op(i, j) for op in ops for i in range(1, 7) for j in range(1, 7))


-- 
Steven


From rosuav at gmail.com  Sun May 26 00:02:29 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 14:02:29 +1000
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <51a17cff$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
	<CAPTjJmrNodc7S5eOCeQEZdvz+3r06o4XnSgFx1ht7Ne1qDYpmw@mail.gmail.com>
	<BLU176-W31B6CDED0C7EBB19C87FFCD7940@phx.gbl>
	<mailman.2127.1369473306.3114.python-list@python.org>
	<51a0ca91$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2137.1369496527.3114.python-list@python.org>
	<51a17cff$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmo3Uk7pOP8qvbQADQXSfbdXVJzEGazNP0i6e3V+s8_zxg@mail.gmail.com>

On Sun, May 26, 2013 at 1:09 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> You're right, all my dice are eight-sided and complex:
>
> 1+0i
> 1+1i
> 1-1i
> -1+0i
> -1+1i
> -1-1i
>
>
> :-)

Now THAT is a dice of win!

>> Now, I have here with me
>> a set used for maths drill (to be entirely accurate, what I have here is
>> the company's stock of them, so there are multiples of each of these -
>> anyone need to buy dice?)
>
> Are you serious? What's the cost, posted to Melbourne?

$1 each, postage probably $5 for any number. Or there may even be
option to pick up / hand deliver, depending on where in Melb you are.

http://www.kepl.com.au/ - company's winding down, but we still have stock.

> Oh, you mean ? (division sign)! Why didn't you say so? :-P

I tend to stick to ASCII in these posts. :)

> And another thing, shame on you, you mean ? not x. It's easy to find too:
>
> py> from unicodedata import lookup
> py> print(lookup("MULTIPLICATION SIGN"))
> ?

I'm aware of that, but see above, I stick to ASCII where possible. The
faces would be better represented with some of the other digits (the
bolded ones, perhaps), but I used the ASCII digits. :)

>> Plus, if you roll 2d6 (that is, two
>> regular six-sided dice and add them up), 7 is statistically the most
>> likely number to come up with. Therefore it IS random.
>
> Yes, but if you subtract them the most common is 0, if you multiply the
> most common are 6 or 12, and if you divide the most common is 1. If you
> decide on the operation randomly, using the +-??+ die above (ignoring
> wildcards), the most common result is 6. The probability of getting a 7
> is just 1/15.
>
> from collections import Counter
> from operator import add, sub, mul, truediv as div
> ops = (add, sub, mul, div, add)
> Counter(op(i, j) for op in ops for i in range(1, 7) for j in range(1, 7))

LOL! I never thought to go THAT far into the analysis..... Nice one!

ChrisA


From breamoreboy at yahoo.co.uk  Sat May 25 08:01:06 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 25 May 2013 13:01:06 +0100
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>,
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>,
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>,
	<BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>,
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>
Message-ID: <knq955$m99$1@ger.gmane.org>

On 25/05/2013 09:54, Carlos Nepomuceno wrote:
> lol
>
> def absolute(x):
>      return x if x>0 else -x
>
> def reach(x):
>      y=[]
>      z=0
>      while z<x:
>          y.append(z)
>          z+=1
>      return y
>

In my book this is another fail as lists are inbuilt (yuck!) and so is 
the add function that'll be called for z+=1.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From carlosnepomuceno at outlook.com  Sat May 25 13:07:47 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 20:07:47 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <knq955$m99$1@ger.gmane.org>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>, ,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>, ,
	<mailman.2109.1369459444.3114.python-list@python.org>, ,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>, ,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>, ,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>, ,
	<BLU176-W22ACF37B4898379CD64258D7940@phx.gbl>, ,
	<CAPTjJmrTma=7xx2q37Ak8XoEc8UziKVEL77YLxkVac0+yrfhqA@mail.gmail.com>,
	, <BLU176-W1833A5275DD72D3BBC43F7D7940@phx.gbl>, ,
	<CAPTjJmofQJ03a47C=LsnZKYv-37=qpYU-Asd5bRd+NopH5JdCA@mail.gmail.com>,
	<BLU176-W34BB46913B9DB79761CAE0D7940@phx.gbl>,
	<knq955$m99$1@ger.gmane.org>
Message-ID: <BLU176-W48979EDFF791EDD1CE494BD7940@phx.gbl>

----------------------------------------
> To: python-list at python.org
> From: breamoreboy at yahoo.co.uk
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> Date: Sat, 25 May 2013 13:01:06 +0100
[...]
> In my book this is another fail as lists are inbuilt (yuck!) and so is
> the add function that'll be called for z+=1.

Indeed! It's a joke Mark! lol
;) 		 	   		  

From roy at panix.com  Sat May 25 10:03:24 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 25 May 2013 10:03:24 -0400
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
Message-ID: <roy-669DAF.10032325052013@news.panix.com>

In article <74e33270-a79a-4878-a400-8a6cda6637b2 at googlegroups.com>,
 lokeshkoppaka at gmail.com wrote:

> ya steven i had done the similar logic but thats not satisfying my professor 
> he had given the following constrains
>  1. No in-built functions should be used
>  2. we are expecting a O(n) solution
>  3. Don't use count method

A couple of points here:

1) In general, people on mailing lists are not into doing homework 
problems for other people.

2) If you're going to bring us a homework problem, at least describe the 
whole problem up front.  It really doesn't help to dribble out new 
requirements one at a time.

3) rustompmody at gmail.com already posted a pointer to the wikipedia 
article describing the required algorithm in detail.

4) I don't know what "no built-in functions should be used" means.  I 
assume it means, "don't call sort()"?  If you can't even call 
int.__lt__(), it's going to be really hard to do this.


From davea at davea.name  Sat May 25 10:27:02 2013
From: davea at davea.name (Dave Angel)
Date: Sat, 25 May 2013 10:27:02 -0400
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <roy-669DAF.10032325052013@news.panix.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
	<roy-669DAF.10032325052013@news.panix.com>
Message-ID: <51A0CA36.4050404@davea.name>

On 05/25/2013 10:03 AM, Roy Smith wrote:
> In article <74e33270-a79a-4878-a400-8a6cda6637b2 at googlegroups.com>,
>   lokeshkoppaka at gmail.com wrote:
>
>> ya steven i had done the similar logic but thats not satisfying my professor
>> he had given the following constrains
>>   1. No in-built functions should be used
>>   2. we are expecting a O(n) solution
>>   3. Don't use count method
>
> A couple of points here:
>
> 1) In general, people on mailing lists are not into doing homework
> problems for other people.
>
> 2) If you're going to bring us a homework problem, at least describe the
> whole problem up front.  It really doesn't help to dribble out new
> requirements one at a time.
>
> 3) rustompmody at gmail.com already posted a pointer to the wikipedia
> article describing the required algorithm in detail.
>
> 4) I don't know what "no built-in functions should be used" means.  I
> assume it means, "don't call sort()"?  If you can't even call
> int.__lt__(), it's going to be really hard to do this.
>

The OP has already admitted that he didn't want a sort at all.  He wants 
to COUNT the items, not sort them.  So nothing in his orginal post 
relates to the real homework assignment.

-- 
DaveA


From steve+comp.lang.python at pearwood.info  Sat May 25 10:30:22 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 25 May 2013 14:30:22 GMT
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<mailman.2109.1369459444.3114.python-list@python.org>
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
Message-ID: <51a0cafd$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Fri, 24 May 2013 23:05:17 -0700, lokeshkoppaka wrote:

> On Saturday, May 25, 2013 11:27:38 AM UTC+5:30, Steven D'Aprano wrote:

>> tally = 0
>> for item in list_of_items:
>>     if item == 0:
>>         tally = tally + 1
>> 
>> print "The number of zeroes equals", tally
> 
>
> ya steven i had done the similar logic but thats not satisfying my
> professor he had given the following constrains
>  1. No in-built functions should be used 

The above does not use any built-in functions.

> 2. we are expecting a O(n) solution

The above is O(n).

>  3. Don't use count method

The above does not use the count method.



-- 
Steven


From carlosnepomuceno at outlook.com  Sat May 25 13:45:40 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 20:45:40 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
In-Reply-To: <74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>,
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>,
	<mailman.2109.1369459444.3114.python-list@python.org>,
	<39ac7437-857e-483f-998c-8162c1039933@googlegroups.com>,
	<51a052d1$0$6599$c3e8da3$5496439d@news.astraweb.com>,
	<74e33270-a79a-4878-a400-8a6cda6637b2@googlegroups.com>
Message-ID: <BLU176-W4335FB6AD0B4D8F205AD3CD7940@phx.gbl>

----------------------------------------
> Date: Fri, 24 May 2013 23:05:17 -0700
> Subject: Re: help how to sort a list in order of 'n' in python without using inbuilt functions??
> From: lokeshkoppaka at gmail.com
[...]

> ya steven i had done the similar logic but thats not satisfying my professor
> he had given the following constrains
> 1. No in-built functions should be used
> 2. we are expecting a O(n) solution
> 3. Don't use count method


PS: If you find something faster please let me know! 		 	   		  

From rustompmody at gmail.com  Sat May 25 01:43:18 2013
From: rustompmody at gmail.com (rusi)
Date: Fri, 24 May 2013 22:43:18 -0700 (PDT)
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
Message-ID: <db89bfd0-93bc-4503-874a-dc8383d6cfda@ow4g2000pbc.googlegroups.com>

On May 25, 10:15?am, lokeshkopp... at gmail.com wrote:
> On Friday, May 24, 2013 1:34:51 PM UTC+5:30, lokesh... at gmail.com wrote:
> > i need to write a code which can sort the list in order of 'n' without use builtin functions
>
> > can anyone help me how to do?
>
> ?Note:
> the list only contains 0's,1's,2's
> need to sort them in order of 'n'

Its a classic problem
http://en.wikipedia.org/wiki/Dutch_national_flag_problem


From roy at panix.com  Sat May 25 09:29:57 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 25 May 2013 09:29:57 -0400
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
Message-ID: <roy-CAE16C.09295725052013@news.panix.com>

In article <78192328-b31b-49d9-9cd6-ec742c092a29 at googlegroups.com>,
 lokeshkoppaka at gmail.com wrote:

> On Friday, May 24, 2013 1:34:51 PM UTC+5:30, lokesh... at gmail.com wrote:
> > i need to write a code which can sort the list in order of 'n' without use 
> > builtin functions 
> > 
> > can anyone help me how to do?
> 
>  Note:
> the list only contains 0's,1's,2's
> need to sort them in order of 'n'

What do you mean by "need to sort them in order of 'n'".  Are you saying 
that you need to sort them into numerical order?  Or that you need to 
running time of the algorithm to be O(n)?

I'm assuming the later, in which case this is starting to sound like a 
classic interview question.

Assuming you can accept an unstable sort, there's an easy solution.  I'm 
not aware of any solution if you require a stable sort.  Perhaps that's 
enough of a hint?


From jpiitula at ling.helsinki.fi  Sat May 25 10:59:30 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 25 May 2013 17:59:30 +0300
Subject: help how to sort a list in order of 'n' in python without using
	inbuilt functions??
References: <e31fbc7c-1bc0-4f9a-9f1d-68f963a9ec39@googlegroups.com>
	<78192328-b31b-49d9-9cd6-ec742c092a29@googlegroups.com>
	<roy-CAE16C.09295725052013@news.panix.com>
Message-ID: <qot8v3314x9.fsf@ruuvi.it.helsinki.fi>

Roy Smith writes:

> In article <78192328-b31b-49d9-9cd6-ec742c092a29 at googlegroups.com>,
>  lokeshkoppaka at gmail.com wrote:
> 
> > On Friday, May 24, 2013 1:34:51 PM UTC+5:30, lokesh... at gmail.com wrote:
> > > i need to write a code which can sort the list in order of 'n'
> > > without use builtin functions
> > > 
> > > can anyone help me how to do?
> > 
> >  Note:
> > the list only contains 0's,1's,2's
> > need to sort them in order of 'n'
> 
> What do you mean by "need to sort them in order of 'n'".  Are you
> saying that you need to sort them into numerical order?  Or that you
> need to running time of the algorithm to be O(n)?
> 
> I'm assuming the later, in which case this is starting to sound like
> a classic interview question.
> 
> Assuming you can accept an unstable sort, there's an easy solution.
> I'm not aware of any solution if you require a stable sort.  Perhaps
> that's enough of a hint?

Surely it's assumed that each element of the input list can be
classified as 0, 1, or 2 in O(1) time. If O(n) auxiliary space can be
allocated in O(n) time, just put the 0's in their own list in the
order they are encountered, 1's in their own list in the order they
are encountered, 2's in their own list in the order they are
encountered, then put the 0's back into the input list in the order
they are encountered in their auxiliary list, followed by the 1's,
followed by the 2's. Stable and O(n), no?

Even ( [ x for x in input if x.key == 0 ] +
       [ x for x in input if x.key == 1 ] +
       [ x for x in input if x.key == 2 ] ).
I suppose a list comprehension is not technically a function any more
than a loop is.

(Neither stability nor O(1) space has been required yet, I think.)


From peter.h.m.brooks at gmail.com  Fri May 24 04:14:45 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Fri, 24 May 2013 01:14:45 -0700 (PDT)
Subject: Simple algorithm question - how to reorder a sequence economically
Message-ID: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>

What is the easiest way to reorder a sequence pseudo-randomly?

That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
2,1,4,3) that is different each time.

I'm writing a simulation and would like to visit all the nodes in a
different order at each iteration of the simulation to remove the risk
of a fixed order introducing spurious evidence of correlation.


From rosuav at gmail.com  Fri May 24 04:37:49 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 18:37:49 +1000
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
Message-ID: <CAPTjJmqmWBACxzrFQzVzRDOvft47S7dbeAedFbPTyiahyjpEVQ@mail.gmail.com>

On Fri, May 24, 2013 at 6:14 PM, Peter Brooks
<peter.h.m.brooks at gmail.com> wrote:
> What is the easiest way to reorder a sequence pseudo-randomly?
>
> That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
> 2,1,4,3) that is different each time.
>
> I'm writing a simulation and would like to visit all the nodes in a
> different order at each iteration of the simulation to remove the risk
> of a fixed order introducing spurious evidence of correlation.

Permuting a sequence iteratively to cover every possibility? Good fun.

Here's one way of looking at it. Imagine the indices of all elements
are in some special "base" like so:

[a, b, c, d] --> a*4+b*3+c*2+d*1

Then iterate up to the highest possible value (ie 4*3*2*1), picking
indices for each accordingly. I don't know how efficient this will be,
but here's a simple piece of code to do it:

>>> def permute(lst,pos):
	lst=lst[:] # Take a copy
	ret=[None]*len(lst)
	for i in range(len(lst)):
		pos,idx=divmod(pos,len(lst))
		ret[i]=lst[idx]
		del lst[idx]
	return ret

>>> for i in range(4*3*2*1):
	permute([10,20,30,40],i)

	
[10, 20, 30, 40]
[20, 10, 30, 40]
[30, 10, 20, 40]
[40, 10, 20, 30]
[10, 30, 20, 40]
[20, 30, 10, 40]
[30, 20, 10, 40]
[40, 20, 10, 30]
[10, 40, 20, 30]
[20, 40, 10, 30]
[30, 40, 10, 20]
[40, 30, 10, 20]
[10, 20, 40, 30]
[20, 10, 40, 30]
[30, 10, 40, 20]
[40, 10, 30, 20]
[10, 30, 40, 20]
[20, 30, 40, 10]
[30, 20, 40, 10]
[40, 20, 30, 10]
[10, 40, 30, 20]
[20, 40, 30, 10]
[30, 40, 20, 10]
[40, 30, 20, 10]

It works, it produces a unique list for any given index provided, but
it's not the cleanest or most efficient. But I know someone'll improve
on it... or tell me I'm an idiot for not taking a more obvious
approach :)

ChrisA


From fabiosantosart at gmail.com  Fri May 24 04:47:07 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Fri, 24 May 2013 09:47:07 +0100
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <CAPTjJmqmWBACxzrFQzVzRDOvft47S7dbeAedFbPTyiahyjpEVQ@mail.gmail.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<CAPTjJmqmWBACxzrFQzVzRDOvft47S7dbeAedFbPTyiahyjpEVQ@mail.gmail.com>
Message-ID: <CAA=1kxSmj_BFwYbvi2yGMSbmCdbtz=7jKo0ADfHCj7s7DXxn-A@mail.gmail.com>

On 24 May 2013 09:41, "Chris Angelico" <rosuav at gmail.com> wrote:
>
> On Fri, May 24, 2013 at 6:14 PM, Peter Brooks
> <peter.h.m.brooks at gmail.com> wrote:
> > What is the easiest way to reorder a sequence pseudo-randomly?
> >
> > That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
> > 2,1,4,3) that is different each time.
> >
...
> It works, it produces a unique list for any given index provided, but
> it's not the cleanest or most efficient. But I know someone'll improve
> on it... or tell me I'm an idiot for not taking a more obvious
> approach :)
>
> ChrisA

I think that is pretty much itertools.permutations from the standard
library. The OP should check it out.
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From rosuav at gmail.com  Fri May 24 05:11:11 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 19:11:11 +1000
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <CAA=1kxSmj_BFwYbvi2yGMSbmCdbtz=7jKo0ADfHCj7s7DXxn-A@mail.gmail.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<CAPTjJmqmWBACxzrFQzVzRDOvft47S7dbeAedFbPTyiahyjpEVQ@mail.gmail.com>
	<CAA=1kxSmj_BFwYbvi2yGMSbmCdbtz=7jKo0ADfHCj7s7DXxn-A@mail.gmail.com>
Message-ID: <CAPTjJmpZ+uiVAXixLqbn+tGXhK9Tzp5ri1fJ7OfZyZPPV63BJg@mail.gmail.com>

On Fri, May 24, 2013 at 6:47 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
>
> On 24 May 2013 09:41, "Chris Angelico" <rosuav at gmail.com> wrote:
>>
>> On Fri, May 24, 2013 at 6:14 PM, Peter Brooks
>> <peter.h.m.brooks at gmail.com> wrote:
>> > What is the easiest way to reorder a sequence pseudo-randomly?
>> >
>> > That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
>> > 2,1,4,3) that is different each time.
>> >
> ...
>
>> It works, it produces a unique list for any given index provided, but
>> it's not the cleanest or most efficient. But I know someone'll improve
>> on it... or tell me I'm an idiot for not taking a more obvious
>> approach :)
>>
>> ChrisA
>
> I think that is pretty much itertools.permutations from the standard
> library. The OP should check it out.

That works if all the permutations are wanted at once. Is there a way,
short of iterating over it N times, to request permutation #N? Or
maybe I'm misreading the OP and that's not a requirement.

ChrisA


From buzzard at invalid.invalid  Fri May 24 10:33:26 2013
From: buzzard at invalid.invalid (duncan smith)
Date: Fri, 24 May 2013 15:33:26 +0100
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <mailman.2053.1369387054.3114.python-list@python.org>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<CAPTjJmqmWBACxzrFQzVzRDOvft47S7dbeAedFbPTyiahyjpEVQ@mail.gmail.com>
	<CAA=1kxSmj_BFwYbvi2yGMSbmCdbtz=7jKo0ADfHCj7s7DXxn-A@mail.gmail.com>
	<mailman.2053.1369387054.3114.python-list@python.org>
Message-ID: <519f7a3a$0$32543$862e30e2@ngroups.net>

On 24/05/13 10:11, Chris Angelico wrote:
> On Fri, May 24, 2013 at 6:47 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
>>
>> On 24 May 2013 09:41, "Chris Angelico" <rosuav at gmail.com> wrote:
>>>
>>> On Fri, May 24, 2013 at 6:14 PM, Peter Brooks
>>> <peter.h.m.brooks at gmail.com> wrote:
>>>> What is the easiest way to reorder a sequence pseudo-randomly?
>>>>
>>>> That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
>>>> 2,1,4,3) that is different each time.
>>>>
>> ...
>>
>>> It works, it produces a unique list for any given index provided, but
>>> it's not the cleanest or most efficient. But I know someone'll improve
>>> on it... or tell me I'm an idiot for not taking a more obvious
>>> approach :)
>>>
>>> ChrisA
>>
>> I think that is pretty much itertools.permutations from the standard
>> library. The OP should check it out.
>
> That works if all the permutations are wanted at once. Is there a way,
> short of iterating over it N times, to request permutation #N? Or
> maybe I'm misreading the OP and that's not a requirement.
>
> ChrisA
>

A long time ago I wrote some code to do that.


import gmpy

def LexPermFromIndex(items, index):
     n = len(items)
     inds = range(n)
     perm = []
     for i in range(1, n+1):
         r, index = divmod(index, gmpy.fac(n-i))
         r = int(r)
         perm.append(inds[r])
         inds = inds[:r] + inds[r+1:]

     return [items[i] for i in perm]


 >>> LexPermFromIndex([1,2,3,4], 0)
[1, 2, 3, 4]
 >>> LexPermFromIndex([1,2,3,4], 1)
[1, 2, 4, 3]
 >>> LexPermFromIndex([1,2,3,4], 10)
[2, 4, 1, 3]
 >>>


I can't remember exactly why I wrote it. But I also have something for 
generating a permutation's index and similar functions for combinations.

Duncan


From tjreedy at udel.edu  Fri May 24 06:10:26 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Fri, 24 May 2013 06:10:26 -0400
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
Message-ID: <knnea7$grc$1@ger.gmane.org>

On 5/24/2013 4:14 AM, Peter Brooks wrote:
> What is the easiest way to reorder a sequence pseudo-randomly?
>
> That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
> 2,1,4,3) that is different each time.
>
> I'm writing a simulation and would like to visit all the nodes in a
> different order at each iteration of the simulation to remove the risk
> of a fixed order introducing spurious evidence of correlation.

random module has a shuffle function I believe




From steve+comp.lang.python at pearwood.info  Fri May 24 06:52:18 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 24 May 2013 10:52:18 GMT
Subject: Simple algorithm question - how to reorder a sequence economically
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
Message-ID: <519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>

On Fri, 24 May 2013 01:14:45 -0700, Peter Brooks wrote:

> What is the easiest way to reorder a sequence pseudo-randomly?

import random
random.shuffle(sequence)


The sequence is modified in place, so it must be mutable. Lists are okay, 
tuples are not.


> That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
> 2,1,4,3) that is different each time.

You can't *guarantee* that it will be different each time. With a four-
item list, there are only 4! = 24 combinations, so on average you'll get 
the original order one time in 24. For a ten-item list, that is once 
every 3628800 times, and for a twenty-item list, once in 
2432902008176640000 times. But of course these are *random*, and there's 
always a chance of this:

http://dilbert.com/strips/comic/2001-10-25


-- 
Steven


From ned at nedbatchelder.com  Fri May 24 07:26:00 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Fri, 24 May 2013 07:26:00 -0400
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <519F4E48.7090307@nedbatchelder.com>

On 5/24/2013 6:52 AM, Steven D'Aprano wrote:
> On Fri, 24 May 2013 01:14:45 -0700, Peter Brooks wrote:
>
>> What is the easiest way to reorder a sequence pseudo-randomly?
> import random
> random.shuffle(sequence)
>
>
> The sequence is modified in place, so it must be mutable. Lists are okay,
> tuples are not.
>
>
>> That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
>> 2,1,4,3) that is different each time.
> You can't *guarantee* that it will be different each time. With a four-
> item list, there are only 4! = 24 combinations, so on average you'll get
> the original order one time in 24. For a ten-item list, that is once
> every 3628800 times, and for a twenty-item list, once in
> 2432902008176640000 times. But of course these are *random*, and there's
> always a chance of this:
>
> http://dilbert.com/strips/comic/2001-10-25
>
>

Also, heed the note in the docs:  "Note that for even rather small 
len(x), the total number of permutations of /x/ is larger than the 
period of most random number generators; this implies that most 
permutations of a long sequence can never be generated."  The default 
random number generator has a period of 2**19937-1, which means that 
lists longer than 2080 have more permutations than the period of the 
generator (because factorial(2081) > 2**19937). Most shuffles involve 
lists far shorter than 2080, but it's still good to keep it in mind.

--Ned.
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From peter.h.m.brooks at gmail.com  Fri May 24 09:23:14 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Fri, 24 May 2013 06:23:14 -0700 (PDT)
Subject: Simple algorithm question - how to reorder a sequence economically
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2055.1369394778.3114.python-list@python.org>
Message-ID: <0065152b-16ac-4ce9-8e99-3d0b8e88a31f@fv8g2000vbb.googlegroups.com>

Thank you all for those most helpful suggestions! random.shuffle does
precisely the job that I need quickly. Thank you for introducing me to
itertools, though, I should have remembered APL did this in a symbol
or two and I'm sure that itertools will come in handy in future.

Thanks for the warnings about random numbers too - I hope my lists
will be short enough for the permutations of the function to be
irrelevant. I don't need every single sequence to be unique, only that
the same sequence only occurs occasionally. My lists might get up to
the ~2k length one day, and I'll keep in mind the need, at that stage,
to use a different pseudo-random generator. Actually, thinking about
it, there is probably a source of non-algorithmically-derived 'random'
numbers somewhere on the net that would do the job nicely.


From rosuav at gmail.com  Fri May 24 09:43:16 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 24 May 2013 13:43:16 -0000
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <0065152b-16ac-4ce9-8e99-3d0b8e88a31f@fv8g2000vbb.googlegroups.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2055.1369394778.3114.python-list@python.org>
	<0065152b-16ac-4ce9-8e99-3d0b8e88a31f@fv8g2000vbb.googlegroups.com>
Message-ID: <CAPTjJmriUH_pdi6cf4gpW0R=9HyFseRUHLhGCcY=Jg73=-BGJg@mail.gmail.com>

On Fri, May 24, 2013 at 11:23 PM, Peter Brooks
<peter.h.m.brooks at gmail.com> wrote:
> Actually, thinking about
> it, there is probably a source of non-algorithmically-derived 'random'
> numbers somewhere on the net that would do the job nicely.

True entropy is usually provided by a source such as /dev/random (on
Unix systems). It's sometimes referred to as "cryptographic"
randomness, due to its necessity in secure encryption work. There are
various ways to get this in a cross-platform way.

ChrisA


From steve+comp.lang.python at pearwood.info  Fri May 24 09:57:21 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 24 May 2013 13:57:21 GMT
Subject: Simple algorithm question - how to reorder a sequence economically
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2055.1369394778.3114.python-list@python.org>
	<0065152b-16ac-4ce9-8e99-3d0b8e88a31f@fv8g2000vbb.googlegroups.com>
Message-ID: <519f71c0$0$6599$c3e8da3$5496439d@news.astraweb.com>

On Fri, 24 May 2013 06:23:14 -0700, Peter Brooks wrote:


> Thanks for the warnings about random numbers too - I hope my lists will
> be short enough for the permutations of the function to be irrelevant. I
> don't need every single sequence to be unique, only that the same
> sequence only occurs occasionally. My lists might get up to the ~2k
> length one day, and I'll keep in mind the need, at that stage, to use a
> different pseudo-random generator. Actually, thinking about it, there is
> probably a source of non-algorithmically-derived 'random' numbers
> somewhere on the net that would do the job nicely.

That's massive overkill.

Take a closer look at what Ned wrote:

"The default random number generator has a period of 2**19937-1"

and consider the numbers.

For a list with 3000 items, there are 3000! possible permutations. That 
is approximately 10**21024. That is, a number with 21024 digits, or 
somewhere around a trillion trillion trillion ... trillion trillion, 
where there are 1752 "trillions".

If you could generate a million permutations a second, it would take you 
on average 10**210988 centuries before getting the original permutation 
again. That's the expected result you would get with a source of true 
randomness.

Instead, with Python's default pseudo-random number generator, you cannot 
get the full 3000! permutations, but only 2**19937-1 of them. Using the 
same calculation as above, that means that you will have to generate a 
million permutations per second for "only" 10**13783 centuries before 
getting the original permutation again.

There are uses where being able to generate any possible permutation is 
important, and the default PRNG is not sufficient. But merely shuffling 
your data around to avoid spurious correlations is not one of them. Save 
yourself a lot of development effort, and debugging, and just use 
random.shuffle.


-- 
Steven


From john_ladasky at sbcglobal.net  Fri May 24 13:33:47 2013
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Fri, 24 May 2013 10:33:47 -0700 (PDT)
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <a06bdfac-514b-4356-a06a-9f39e6bc5ddc@googlegroups.com>

On Friday, May 24, 2013 3:52:18 AM UTC-7, Steven D'Aprano wrote:
> On Fri, 24 May 2013 01:14:45 -0700, Peter Brooks wrote:
> 
> > That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
> > 2,1,4,3) that is different each time.
> 
> You can't *guarantee* that it will be different each time. 

Well, within limits, you can guarantee a LONG TIME between repeats.  And that may be good enough for Peter's purpose. 

When the number of elements in your sequence is short enough (the right value of "short enough" is at least partially a matter of opinion, and the amount of RAM available, but I would guess n < 10 myself), use itertools.permutations to generate all the possibilities at once -- call this list p.  Store p in memory.  Then shuffle p, and use its elements one at a time.  If you get to the end of p and need to keep working, it's up to you whether to shuffle p a second time.  If you don't reshuffle p, it guarantees the maximum interval between reusing the same permutation.

Use random.shuffle on your sequence directly, when your sequence has a larger number of elements.  This doesn't guarantee that two successive permutations will not be identical, but the probability is of course very low.


From john_ladasky at sbcglobal.net  Sat May 25 21:25:16 2013
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Sat, 25 May 2013 18:25:16 -0700 (PDT)
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <a06bdfac-514b-4356-a06a-9f39e6bc5ddc@googlegroups.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<a06bdfac-514b-4356-a06a-9f39e6bc5ddc@googlegroups.com>
Message-ID: <15a1bb3a-514c-454e-a966-243c84123be9@googlegroups.com>

On Friday, May 24, 2013 10:33:47 AM UTC-7, Yours Truly wrote:
> If you don't reshuffle p, it guarantees the maximum interval between reusing
> the same permutation.

Of course, that comes at a certain price.  Given two permutations p[x] and p[x+1], they will ALWAYS be adjacent, in every repetition of the list, unless you reshuffle.  So the "spurious correlation" problem that Peter is worrying about would still exist, albeit at a meta-level.

You could play clever games, such as splitting p in half once you get to the end of it, shuffling each half independently, and then concatenating the halves.  This algorithm scrambles the p[x]'s and p[x+1]'s pretty well, at the cost of cutting the average interval between repeats of a given p[x] from len(p) to something closer to len(p)/2.

Because someone's got to say it... "The generation of random numbers is too important to be left to chance." ? Robert R. Coveyou


From roy at panix.com  Sat May 25 21:49:28 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 25 May 2013 21:49:28 -0400
Subject: Simple algorithm question - how to reorder a sequence economically
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<a06bdfac-514b-4356-a06a-9f39e6bc5ddc@googlegroups.com>
	<15a1bb3a-514c-454e-a966-243c84123be9@googlegroups.com>
Message-ID: <roy-7C1882.21492825052013@news.panix.com>

In article <15a1bb3a-514c-454e-a966-243c84123be9 at googlegroups.com>,
 John Ladasky <john_ladasky at sbcglobal.net> wrote:

> Because someone's got to say it... "The generation of random numbers is too 
> important to be left to chance." ? Robert R. Coveyou

Absolutely.  I know just enough about random number generation to 
understand that I don't really know anything about it :-)

That being said, people who really care about random numbers, tend to 
rely on some sort of physical process instead of computer algorithms.  A 
classic example would be /dev/random.  A somewhat more fun example is 
http://www.youtube.com/watch?v=7n8LNxGbZbs.  Something radioactive and a 
geiger counter are a good source of randomness (time intervals between 
decay events).


From davea at davea.name  Sat May 25 22:05:14 2013
From: davea at davea.name (Dave Angel)
Date: Sun, 26 May 2013 02:05:14 -0000
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <roy-7C1882.21492825052013@news.panix.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<519f4661$0$6599$c3e8da3$5496439d@news.astraweb.com>
	<a06bdfac-514b-4356-a06a-9f39e6bc5ddc@googlegroups.com>
	<15a1bb3a-514c-454e-a966-243c84123be9@googlegroups.com>
	<roy-7C1882.21492825052013@news.panix.com>
Message-ID: <51A16DCC.1010807@davea.name>

On 05/25/2013 09:49 PM, Roy Smith wrote:
> In article <15a1bb3a-514c-454e-a966-243c84123be9 at googlegroups.com>,
>   John Ladasky <john_ladasky at sbcglobal.net> wrote:
>
>> Because someone's got to say it... "The generation of random numbers is too
>> important to be left to chance." ? Robert R. Coveyou
>
> Absolutely.  I know just enough about random number generation to
> understand that I don't really know anything about it :-)
>
> That being said, people who really care about random numbers, tend to
> rely on some sort of physical process instead of computer algorithms.  A
> classic example would be /dev/random.  A somewhat more fun example is
> http://www.youtube.com/watch?v=7n8LNxGbZbs.  Something radioactive and a
> geiger counter are a good source of randomness (time intervals between
> decay events).
>
>

That's good unless you're a cat, and you belong to Schroedinger...


-- 
DaveA


From carlosnepomuceno at outlook.com  Fri May 24 11:00:59 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 24 May 2013 18:00:59 +0300
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
Message-ID: <BLU176-W23282A01E54B3343BF4656D7AB0@phx.gbl>

----------------------------------------
> Date: Fri, 24 May 2013 01:14:45 -0700
> Subject: Simple algorithm question - how to reorder a sequence economically
> From: peter.h.m.brooks at gmail.com
> To: python-list at python.org
>
> What is the easiest way to reorder a sequence pseudo-randomly?
>
> That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg
> 2,1,4,3) that is different each time.
>
> I'm writing a simulation and would like to visit all the nodes in a
> different order at each iteration of the simulation to remove the risk
> of a fixed order introducing spurious evidence of correlation.
> --
> http://mail.python.org/mailman/listinfo/python-list

I don't know what "spurious evidence of correlation" is. Can you give a mathematical definition?

Here's a snippet for creating a random shuffle by Fisher?Yates algorithm:

def FY_shuffle(l):
??? from random import randint
??? for i in range(len(l)-1,0,-1):
??????? j = randint(0,i)
??????? l[j],l[i] = l[i],l[j]

It looks just like random.shuffle() mentioned before, but you can change it as you see fit.

If you can afford to test all permutations you can iterate over it by doing:

>>> from itertools import permutations
>>> l=range(4)
>>> l
[0, 1, 2, 3]
>>> for i in permutations(l): print i
...
(0, 1, 2, 3)
(0, 1, 3, 2)
(0, 2, 1, 3)
[...]
(3, 1, 2, 0)
(3, 2, 0, 1)
(3, 2, 1, 0)
>>>

Note that 'i' is a tuple.

If you need a list of all permutations to make a selection:

>>> l=range(4)
>>> l
[0, 1, 2, 3]
>>> [list(i) for i in permutations(l)]
[[0, 1, 2, 3], [0, 1, 3, 2], [0, 2, 1, 3], [0, 2, 3, 1], [0, 3, 1, 2], [0, 3, 2, 1], [1, 0, 2, 3], [1, 0, 3, 2], [1, 2, 0, 3], [1, 2, 3, 0], [1, 3, 0, 2], [1, 3, 2, 0], [2, 0, 1, 3], [2, 0, 3, 1], [2, 1, 0, 3], [2, 1, 3, 0], [2, 3, 0, 1], [2, 3, 1, 0], [3, 0, 1, 2], [3, 0, 2, 1], [3, 1, 0, 2], [3, 1, 2, 0], [3, 2, 0, 1], [3, 2, 1, 0]]

This will produce big lists:
-for 10 elements (l=range(10)) the size of the list is about 30MB (on Windows).
-for 11 elements (l=range(11)) the size of the list is about 335MB (on Windows). It took more than 7GB for CPython 2.7.5 to create that list.

Didn't try after that. 		 	   		  

From peter.h.m.brooks at gmail.com  Fri May 24 15:01:35 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Fri, 24 May 2013 12:01:35 -0700 (PDT)
Subject: Simple algorithm question - how to reorder a sequence economically
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>
	<mailman.2068.1369407666.3114.python-list@python.org>
Message-ID: <358d5be7-87e8-4655-82ba-859786cc3d47@l3g2000vbl.googlegroups.com>

On May 24, 5:00?pm, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
wrote:
>
>
> I don't know what "spurious evidence of correlation" is. Can you give a mathematical definition?
>
If I run the simulation with the same sequence, then, because event E1
always comes before event E2, somebody might believe that there is a
causative connection between them in the world that's being simulated,
when, in fact, they only correlate in this way because the sequence is
not being shuffled. That's what it means.

Actually it'll be a bit more subtle than that, because each iteration
of the simulation updates all nodes in one time interval, the events
will not usually show the order of iteration - but, where there are
any secondary effects, that are related to the order in which the
nodes are updated, these will always happen the same way, which is my
concern.


From carlosnepomuceno at outlook.com  Fri May 24 17:33:01 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 00:33:01 +0300
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <358d5be7-87e8-4655-82ba-859786cc3d47@l3g2000vbl.googlegroups.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>,
	<mailman.2068.1369407666.3114.python-list@python.org>,
	<358d5be7-87e8-4655-82ba-859786cc3d47@l3g2000vbl.googlegroups.com>
Message-ID: <BLU176-W14668770CEBD1B1A7B7DDDD7AB0@phx.gbl>

----------------------------------------
> Date: Fri, 24 May 2013 12:01:35 -0700
> Subject: Re: Simple algorithm question - how to reorder a sequence economically
> From: peter.h.m.brooks at gmail.com
> To: python-list at python.org
>
> On May 24, 5:00 pm, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
> wrote:
>>
>>
>> I don't know what "spurious evidence of correlation" is. Can you give a mathematical definition?
>>
> If I run the simulation with the same sequence, then, because event E1
> always comes before event E2, somebody might believe that there is a
> causative connection between them in the world that's being simulated,
> when, in fact, they only correlate in this way because the sequence is
> not being shuffled. That's what it means.

Correlation does not imply causation. If "somebody" is an expert system and you want to avoid it's recognition and/or triggering of some kind, and you can't or don't want to change it's behavior, you may take the random way because it's cheaper.

> Actually it'll be a bit more subtle than that, because each iteration
> of the simulation updates all nodes in one time interval, the events
> will not usually show the order of iteration - but, where there are
> any secondary effects, that are related to the order in which the
> nodes are updated, these will always happen the same way, which is my
> concern.

You should have a more precise understanding of the dependence of the variables you taking in consideration before randomizing the series of events your are using for tests.

I suggest you start using PPMCC. If it's close to zero or negative you wouldn't have to mind about it! ;) 		 	   		  

From peter.h.m.brooks at gmail.com  Fri May 24 20:28:07 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Fri, 24 May 2013 17:28:07 -0700 (PDT)
Subject: Simple algorithm question - how to reorder a sequence economically
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>,
	<mailman.2068.1369407666.3114.python-list@python.org>,
	<358d5be7-87e8-4655-82ba-859786cc3d47@l3g2000vbl.googlegroups.com>
	<mailman.2080.1369431189.3114.python-list@python.org>
Message-ID: <6e0cf171-b4c7-46d1-a66a-dcc194a3e5ad@g9g2000vbl.googlegroups.com>

On May 24, 11:33?pm, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
wrote:
> ----------------------------------------
>
>
>
>
>
>
>
>
>
> > Date: Fri, 24 May 2013 12:01:35 -0700
> > Subject: Re: Simple algorithm question - how to reorder a sequence economically
> > From: peter.h.m.bro... at gmail.com
> > To: python-l... at python.org
>
> > On May 24, 5:00 pm, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
> > wrote:
>
> >> I don't know what "spurious evidence of correlation" is. Can you give a mathematical definition?
>
> > If I run the simulation with the same sequence, then, because event E1
> > always comes before event E2, somebody might believe that there is a
> > causative connection between them in the world that's being simulated,
> > when, in fact, they only correlate in this way because the sequence is
> > not being shuffled. That's what it means.
>
> Correlation does not imply causation. If "somebody" is an expert system and you want to avoid it's recognition and/or triggering of some kind, and you can't or don't want to change it's behavior, you may take the random way because it's cheaper.
>
> > Actually it'll be a bit more subtle than that, because each iteration
> > of the simulation updates all nodes in one time interval, the events
> > will not usually show the order of iteration - but, where there are
> > any secondary effects, that are related to the order in which the
> > nodes are updated, these will always happen the same way, which is my
> > concern.
>
> You should have a more precise understanding of the dependence of the variables you taking in consideration before randomizing the series of events your are using for tests.
>
If the scenario could be modelled mathematically, then there'd be no
point in writing the simulation.


From carlosnepomuceno at outlook.com  Fri May 24 21:52:36 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 01:52:36 -0000
Subject: Simple algorithm question - how to reorder a sequence economically
In-Reply-To: <6e0cf171-b4c7-46d1-a66a-dcc194a3e5ad@g9g2000vbl.googlegroups.com>
References: <a31c773f-88d8-4489-8640-12123d884e4d@m2g2000vbb.googlegroups.com>,
	, <mailman.2068.1369407666.3114.python-list@python.org>, ,
	<358d5be7-87e8-4655-82ba-859786cc3d47@l3g2000vbl.googlegroups.com>,
	<mailman.2080.1369431189.3114.python-list@python.org>,
	<6e0cf171-b4c7-46d1-a66a-dcc194a3e5ad@g9g2000vbl.googlegroups.com>
Message-ID: <BLU176-W44FAD6787A6248EA8028A6D7940@phx.gbl>

----------------------------------------
> Date: Fri, 24 May 2013 17:28:07 -0700
> Subject: Re: Simple algorithm question - how to reorder a sequence economically
> From: peter.h.m.brooks at gmail.com
> To: python-list at python.org
[...]
> If the scenario could be modelled mathematically, then there'd be no
> point in writing the simulation.

I don't know what you mean. A computer simulation is an instance of a mathematical model. 		 	   		  

From peter.h.m.brooks at gmail.com  Fri May 24 04:18:06 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Fri, 24 May 2013 01:18:06 -0700 (PDT)
Subject: Using ACLs in JSON
Message-ID: <6e35fb87-6c6b-4fcc-a99c-199af8b1a4c1@k3g2000vbn.googlegroups.com>

I'm designing a system that should allow different views to different
audiences. I understand that I can use application logic to control
the access security, but it seems to me that it'd make more sense to
have this documented in the data-stream so that it's data-driven.

I was wondering if there was any standard way of doing this in JSON.
Alternatively, is there a better way of organising this in Python
that's compatible with JSON?

I've put an example of the sort of thing that I mean below. The idea
is that this object is accessible for viewing or deleting by the role
'HR' and available for change only to the owner of the record itself.
In addition, the record can be viewed by those with the role
'manager'. The syntax may be wrong, but I hope that my intention is
reasonably clear.

Is there an existing practice or standard for doing this sort of
thing?

{
	"title" : "Example Schema",
	"type"  : "object",
	"version" : "1.0",
	"properties": {
		"firstname" : {
				"type": "string"
		},
		"lastname" : {
				"type": "string"
		},
		"age" : {
			"description" : "Age in years",
			"type": "integer",
			"minimum": 0
		}
	},
	"ACL-view": ["HR","Manager",["firstname","lastname"]],
	"ACL-change": ["firstname","Lastname"],
	"ACL-delete": ["HR"],
	"required": ["firstname","lastname"]
}


From carlosnepomuceno at outlook.com  Fri May 24 12:13:15 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 24 May 2013 19:13:15 +0300
Subject: Using ACLs in JSON
In-Reply-To: <6e35fb87-6c6b-4fcc-a99c-199af8b1a4c1@k3g2000vbn.googlegroups.com>
References: <6e35fb87-6c6b-4fcc-a99c-199af8b1a4c1@k3g2000vbn.googlegroups.com>
Message-ID: <BLU176-W291DE3935E816D23B25713D7AB0@phx.gbl>

Not exactly what you want but you may consider Google ACL XML[1].

If there aren't any system integration restrictions you can do what you think it's best... for now.


[1] https://developers.google.com/storage/docs/accesscontrol#applyacls


----------------------------------------
> Date: Fri, 24 May 2013 01:18:06 -0700
> Subject: Using ACLs in JSON
> From: peter.h.m.brooks at gmail.com
> To: python-list at python.org
>
> I'm designing a system that should allow different views to different
> audiences. I understand that I can use application logic to control
> the access security, but it seems to me that it'd make more sense to
> have this documented in the data-stream so that it's data-driven.
>
> I was wondering if there was any standard way of doing this in JSON.
> Alternatively, is there a better way of organising this in Python
> that's compatible with JSON?
>
> I've put an example of the sort of thing that I mean below. The idea
> is that this object is accessible for viewing or deleting by the role
> 'HR' and available for change only to the owner of the record itself.
> In addition, the record can be viewed by those with the role
> 'manager'. The syntax may be wrong, but I hope that my intention is
> reasonably clear.
>
> Is there an existing practice or standard for doing this sort of
> thing?
>
> {
> "title" : "Example Schema",
> "type" : "object",
> "version" : "1.0",
> "properties": {
> "firstname" : {
> "type": "string"
> },
> "lastname" : {
> "type": "string"
> },
> "age" : {
> "description" : "Age in years",
> "type": "integer",
> "minimum": 0
> }
> },
> "ACL-view": ["HR","Manager",["firstname","lastname"]],
> "ACL-change": ["firstname","Lastname"],
> "ACL-delete": ["HR"],
> "required": ["firstname","lastname"]
> }
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From torriem at gmail.com  Fri May 24 12:42:04 2013
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 24 May 2013 10:42:04 -0600
Subject: Using ACLs in JSON
In-Reply-To: <6e35fb87-6c6b-4fcc-a99c-199af8b1a4c1@k3g2000vbn.googlegroups.com>
References: <6e35fb87-6c6b-4fcc-a99c-199af8b1a4c1@k3g2000vbn.googlegroups.com>
Message-ID: <519F985C.2070501@gmail.com>

On 05/24/2013 02:18 AM, Peter Brooks wrote:
> I'm designing a system that should allow different views to different
> audiences. I understand that I can use application logic to control
> the access security, but it seems to me that it'd make more sense to
> have this documented in the data-stream so that it's data-driven.
> 
> I was wondering if there was any standard way of doing this in JSON.
> Alternatively, is there a better way of organising this in Python
> that's compatible with JSON?

While I don't understand exactly what you're using JSON for, and nor do
I understand the purpose of the JSON structure you posted, I can say
that ACLs have nothing to do with JSON.

JSON is simply a data markup format, like HTML, XML, plain text, or an
INI file.  It's merely data.  If you want to restrict who sees what when
they request a chunk of data formatted using JSON, then you have to
enforce that in the code that's processing the request for data using
another mechanism.  And that mechanism depends on how your clients ask
for JSON data, and what code is serving or generating the JSON data.


From peter.h.m.brooks at gmail.com  Fri May 24 15:06:12 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Fri, 24 May 2013 12:06:12 -0700 (PDT)
Subject: Using ACLs in JSON
References: <6e35fb87-6c6b-4fcc-a99c-199af8b1a4c1@k3g2000vbn.googlegroups.com>
	<mailman.2071.1369413739.3114.python-list@python.org>
Message-ID: <6aa18966-3b98-4ec7-926e-11ca012de30a@gb2g2000vbb.googlegroups.com>

On May 24, 6:42?pm, Michael Torrie <torr... at gmail.com> wrote:
> On 05/24/2013 02:18 AM, Peter Brooks wrote:
>
> > I'm designing a system that should allow different views to different
> > audiences. I understand that I can use application logic to control
> > the access security, but it seems to me that it'd make more sense to
> > have this documented in the data-stream so that it's data-driven.
>
> > I was wondering if there was any standard way of doing this in JSON.
> > Alternatively, is there a better way of organising this in Python
> > that's compatible with JSON?
>
> While I don't understand exactly what you're using JSON for, and nor do
> I understand the purpose of the JSON structure you posted, I can say
> that ACLs have nothing to do with JSON.
>
> JSON is simply a data markup format, like HTML, XML, plain text, or an
> INI file. ?It's merely data. ?If you want to restrict who sees what when
> they request a chunk of data formatted using JSON, then you have to
> enforce that in the code that's processing the request for data using
> another mechanism. ?And that mechanism depends on how your clients ask
> for JSON data, and what code is serving or generating the JSON data.
>
Yes, you're right, I know that. However, I want the permissions
embedded in the data so that it's easy to verify, from the data, who
has access to which objects. The reason is to enforce transparency of
the access rights and to make them easy to grant and change without
needing to make any coding changes.

My question was whether anybody had taken a similar approach and found
a way that worked well with python or, even better, if there was a
standard way of doing this.

If nobody has done this, then I'm happy to invent my own method, but I
don't really want to reinvent wheels that might have been nicely
designed already.



From peter.h.m.brooks at gmail.com  Fri May 24 15:08:03 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Fri, 24 May 2013 12:08:03 -0700 (PDT)
Subject: Using ACLs in JSON
References: <6e35fb87-6c6b-4fcc-a99c-199af8b1a4c1@k3g2000vbn.googlegroups.com>
	<mailman.2070.1369411998.3114.python-list@python.org>
Message-ID: <e313c608-a253-4098-a6c8-179e16107185@g9g2000vbl.googlegroups.com>

On May 24, 6:13?pm, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
wrote:
> Not exactly what you want but you may consider Google ACL XML[1].
>
> If there aren't any system integration restrictions you can do what you think it's best... for now.
>
> [1]https://developers.google.com/storage/docs/accesscontrol#applyacls
>
Thank you for the reference. I specifically don't want to use XML
itself, but I can adapt that to my purpose - great!


From carlosnepomuceno at outlook.com  Fri May 24 17:12:37 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 00:12:37 +0300
Subject: Using ACLs in JSON
In-Reply-To: <e313c608-a253-4098-a6c8-179e16107185@g9g2000vbl.googlegroups.com>
References: <6e35fb87-6c6b-4fcc-a99c-199af8b1a4c1@k3g2000vbn.googlegroups.com>,
	<mailman.2070.1369411998.3114.python-list@python.org>,
	<e313c608-a253-4098-a6c8-179e16107185@g9g2000vbl.googlegroups.com>
Message-ID: <BLU176-W12B514395BDF3DDB4D73A4D7AB0@phx.gbl>

You welcome! Can you send me whatever you decide is best to your case?

I'd like to have an example just in case I have to do that in the future.

I think that approach is gonna become more prevalent in the coming years. ;)

----------------------------------------
> Date: Fri, 24 May 2013 12:08:03 -0700
> Subject: Re: Using ACLs in JSON
> From: peter.h.m.brooks at gmail.com
> To: python-list at python.org
>
> On May 24, 6:13 pm, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
> wrote:
>> Not exactly what you want but you may consider Google ACL XML[1].
>>
>> If there aren't any system integration restrictions you can do what you think it's best... for now.
>>
>> [1]https://developers.google.com/storage/docs/accesscontrol#applyacls
>>
> Thank you for the reference. I specifically don't want to use XML
> itself, but I can adapt that to my purpose - great!
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rvince99 at gmail.com  Fri May 24 07:40:22 2013
From: rvince99 at gmail.com (RVic)
Date: Fri, 24 May 2013 04:40:22 -0700 (PDT)
Subject: Polymoprhism question
Message-ID: <c89c2c9a-4896-4573-90f4-225a1ce6d950@googlegroups.com>

I'm trying to figure out (or find an example) of polymorphism whereby I pass a commandline argument (a string) which comports to a class (in java, you would say that it comports to a given interface bu I don't know if there is such a thing in Python) then that class of that name, somehow gets intantiated from that string. This way, I can have similar classes, but have my program use various ones by simply changing the commandline argument.

Can anyone show me how this might be done in Python? Thanks.

-RVic


From steve+comp.lang.python at pearwood.info  Fri May 24 08:10:16 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 24 May 2013 12:10:16 GMT
Subject: Polymoprhism question
References: <c89c2c9a-4896-4573-90f4-225a1ce6d950@googlegroups.com>
Message-ID: <519f58a7$0$6599$c3e8da3$5496439d@news.astraweb.com>

On Fri, 24 May 2013 04:40:22 -0700, RVic wrote:

> I'm trying to figure out (or find an example) of polymorphism whereby I
> pass a commandline argument (a string) which comports to a class (in
> java, you would say that it comports to a given interface bu I don't
> know if there is such a thing in Python) then that class of that name,
> somehow gets intantiated from that string. This way, I can have similar
> classes, but have my program use various ones by simply changing the
> commandline argument.
> 
> Can anyone show me how this might be done in Python? Thanks.


I'm not 100% sure I understand what you want, but my guess is you want 
something like this:


# A toy class.
class AClass(object):
    def __init__(self, astring):
        self.astring = astring
    def __repr__(self):
        return "%s(%r)" % (self.__class__.__name__, self.astring)

# And some variations.
class BClass(AClass):
    pass

class CClass(AClass):
    pass


# Build a dispatch table, mapping the class name to the class itself.
TABLE = {}
for cls in (AClass, BClass, CClass):
    TABLE[cls.__name__] = cls


# Get the name of the class, and an argument, from the command line.
# Or from the user. Any source of two strings will do.
# Data validation is left as an exercise.
import sys
argv = sys.argv[1:]
if not argv:
    name = raw_input("Name of the class to use? ")
    arg = raw_input("And the argument to use? ")
    argv = [name, arg]


# Instantiate.
instance = TABLE[argv[0]](argv[1])
print instance


-- 
Steven


From rvince99 at gmail.com  Fri May 24 15:19:20 2013
From: rvince99 at gmail.com (RVic)
Date: Fri, 24 May 2013 12:19:20 -0700 (PDT)
Subject: Polymoprhism question
In-Reply-To: <c89c2c9a-4896-4573-90f4-225a1ce6d950@googlegroups.com>
References: <c89c2c9a-4896-4573-90f4-225a1ce6d950@googlegroups.com>
Message-ID: <3f9acff7-151b-4aa4-8b59-fcddc2755691@googlegroups.com>

Thanks Steven,

Yes, I see Python isn't going to do this very well, from what I can understand.

Lets say I have a type of class, and this type of class will always have two methods, in() and out().

Here is, essentially, what I am trying to do, but I don't know if this will make sense to you or if it is really doable in Python:  #thanks, RVic

import sys
argv = sys.argv[1:] 
ClassIamInstantiating = argv
ClassIamInstantiating.in("something")
x = ClassIamInstantiating.out()


From neilc at norwich.edu  Fri May 24 16:23:48 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 24 May 2013 20:23:48 GMT
Subject: Polymoprhism question
References: <c89c2c9a-4896-4573-90f4-225a1ce6d950@googlegroups.com>
	<3f9acff7-151b-4aa4-8b59-fcddc2755691@googlegroups.com>
Message-ID: <b0a0ikFo8f2U1@mid.individual.net>

On 2013-05-24, RVic <rvince99 at gmail.com> wrote:
> Thanks Steven,
>
> Yes, I see Python isn't going to do this very well, from what I
> can understand.
>
> Lets say I have a type of class, and this type of class will
> always have two methods, in() and out().
>
> Here is, essentially, what I am trying to do, but I don't know
> if this will make sense to you or if it is really doable in
> Python:  #thanks, RVic
>
> import sys
> argv = sys.argv[1:] 
> ClassIamInstantiating = argv
> ClassIamInstantiating.in("something")
> x = ClassIamInstantiating.out()

This is pretty easy in Python using the __name__ attribute.

import sys

class A:
 def in(self):
   print("A in")
 def out(self):
   print("A out")

class B:
 def in(self):
   print("B in")
 def out(self):
   print("B out")

classes = {cls.__name__: cls for cls in (A, B)}

ArgType = classes[sys.agrv[1]]

arg = ArgType()

arg.in("test")
arg.out("test")

-- 
Neil Cerutti


From malte.forkel at berlin.de  Fri May 24 08:58:24 2013
From: malte.forkel at berlin.de (Malte Forkel)
Date: Fri, 24 May 2013 14:58:24 +0200
Subject: Utility to locate errors in regular expressions
Message-ID: <knno5h$t9f$1@ger.gmane.org>

Finding out why a regular expression does not match a given string can
very tedious. I would like to write a utility that identifies the
sub-expression causing the non-match. My idea is to use a parser to
create a tree representing the complete regular expression. Then I could
simplify the expression by dropping sub-expressions one by one from
right to left and from bottom to top until the remaining regex matches.
The last sub-expression dropped should be (part of) the problem.

As a first step, I am looking for a parser for Python regular
expressions, or a Python regex grammar to create a parser from.

But may be my idea is flawed? Or a similar (or better) tools already
exists? Any advice will be highly appreciated!

Malte



From jeanpierreda at gmail.com  Fri May 24 09:13:41 2013
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Fri, 24 May 2013 09:13:41 -0400
Subject: Utility to locate errors in regular expressions
In-Reply-To: <knno5h$t9f$1@ger.gmane.org>
References: <knno5h$t9f$1@ger.gmane.org>
Message-ID: <CABicbJKymjXyYHYaD7Fd5dW5jLTLzdGeErGP=X9GFxT+uRfOmA@mail.gmail.com>

On Fri, May 24, 2013 at 8:58 AM, Malte Forkel <malte.forkel at berlin.de> wrote:
> As a first step, I am looking for a parser for Python regular
> expressions, or a Python regex grammar to create a parser from.

the sre_parse module is undocumented, but very usable.

> But may be my idea is flawed? Or a similar (or better) tools already
> exists? Any advice will be highly appreciated!

I think your task is made problematic by the possibility that no
single part of the regexp causes a match failure. What causes failure
depends on what branches are chosen with the |, *, +, ?, etc.
operators -- it might be a different character/subexpression for each
branch. And then there's exponentially many possible branches.

-- Devin


From roy at panix.com  Fri May 24 09:12:16 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 24 May 2013 09:12:16 -0400
Subject: Utility to locate errors in regular expressions
References: <mailman.2062.1369400329.3114.python-list@python.org>
Message-ID: <roy-14A84E.09121624052013@news.panix.com>

In article <mailman.2062.1369400329.3114.python-list at python.org>,
 Malte Forkel <malte.forkel at berlin.de> wrote:

> Finding out why a regular expression does not match a given string can
> very tedious. I would like to write a utility that identifies the
> sub-expression causing the non-match. My idea is to use a parser to
> create a tree representing the complete regular expression. Then I could
> simplify the expression by dropping sub-expressions one by one from
> right to left and from bottom to top until the remaining regex matches.
> The last sub-expression dropped should be (part of) the problem.
> 
> As a first step, I am looking for a parser for Python regular
> expressions, or a Python regex grammar to create a parser from.
> 
> But may be my idea is flawed? Or a similar (or better) tools already
> exists? Any advice will be highly appreciated!

I think this would be a really cool tool.  The debugging process I've 
always used is essentially what you describe.  I start try progressively 
shorter sub-patterns until I get a match, then try to incrementally add 
back little bits of the original pattern until it no longer matches.  
With luck, the problem will become obvious at that point.

Having a tool which automated this would be really useful.

Of course, most of Python user community are wimps and shy away from big 
hairy regexes [ducking and running].


From neilc at norwich.edu  Fri May 24 09:58:37 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 24 May 2013 13:58:37 GMT
Subject: Utility to locate errors in regular expressions
References: <mailman.2062.1369400329.3114.python-list@python.org>
	<roy-14A84E.09121624052013@news.panix.com>
Message-ID: <b09a0dFj505U1@mid.individual.net>

On 2013-05-24, Roy Smith <roy at panix.com> wrote:
> Of course, most of Python user community are wimps and shy away
> from big hairy regexes [ducking and running].

I prefer the simple, lumbering regular expressions like those in
the original Night of the Regular Expressions. The fast, powerful
ones from programs like the remake of Dawn of the GREP, just
aren't as scary.

-- 
Neil Cerutti


From rustompmody at gmail.com  Fri May 24 10:09:41 2013
From: rustompmody at gmail.com (rusi)
Date: Fri, 24 May 2013 07:09:41 -0700 (PDT)
Subject: Utility to locate errors in regular expressions
References: <mailman.2062.1369400329.3114.python-list@python.org>
Message-ID: <a9ff7e3a-4e98-4a9f-9c84-db9f8bca3130@li6g2000pbb.googlegroups.com>

On May 24, 5:58?pm, Malte Forkel <malte.for... at berlin.de> wrote:
> Finding out why a regular expression does not match a given string can
> very tedious. I would like to write a utility that identifies the
> sub-expression causing the non-match. My idea is to use a parser to
> create a tree representing the complete regular expression. Then I could
> simplify the expression by dropping sub-expressions one by one from
> right to left and from bottom to top until the remaining regex matches.
> The last sub-expression dropped should be (part of) the problem.
>
> As a first step, I am looking for a parser for Python regular
> expressions, or a Python regex grammar to create a parser from.
>
> But may be my idea is flawed? Or a similar (or better) tools already
> exists? Any advice will be highly appreciated!
>
> Malte



python-specific:  http://kodos.sourceforge.net/
Online: http://gskinner.com/RegExr/
emacs-specific: re-builder and regex-tool http://bc.tech.coop/blog/071103.html


From auriocus at gmx.de  Fri May 24 14:21:39 2013
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Fri, 24 May 2013 20:21:39 +0200
Subject: Utility to locate errors in regular expressions
In-Reply-To: <mailman.2062.1369400329.3114.python-list@python.org>
References: <mailman.2062.1369400329.3114.python-list@python.org>
Message-ID: <knoaru$4lr$1@dont-email.me>

Am 24.05.13 14:58, schrieb Malte Forkel:
> Finding out why a regular expression does not match a given string can
> very tedious. I would like to write a utility that identifies the
> sub-expression causing the non-match.

Try

	http://laurent.riesterer.free.fr/regexp/

it shows the subexpressions which cause the match by coloring the parts. 
Not exacty what you want, but very intuitive and powerful. Beware this 
is Tcl and there might be subtle differences in RE syntax, but largely 
it's the same.

	Christian


From roy at panix.com  Fri May 24 09:40:12 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 24 May 2013 09:40:12 -0400
Subject: Utility to locate errors in regular expressions
References: <knno5h$t9f$1@ger.gmane.org>
	<mailman.2065.1369401265.3114.python-list@python.org>
Message-ID: <roy-FF225E.09401224052013@news.panix.com>

In article <mailman.2065.1369401265.3114.python-list at python.org>,
 Devin Jeanpierre <jeanpierreda at gmail.com> wrote:

> On Fri, May 24, 2013 at 8:58 AM, Malte Forkel <malte.forkel at berlin.de> wrote:
> > As a first step, I am looking for a parser for Python regular
> > expressions, or a Python regex grammar to create a parser from.
> 
> the sre_parse module is undocumented, but very usable.
> 
> > But may be my idea is flawed? Or a similar (or better) tools already
> > exists? Any advice will be highly appreciated!
> 
> I think your task is made problematic by the possibility that no
> single part of the regexp causes a match failure. What causes failure
> depends on what branches are chosen with the |, *, +, ?, etc.
> operators -- it might be a different character/subexpression for each
> branch. And then there's exponentially many possible branches.

That's certainly true.  The full power of regex makes stuff like this 
very hard to do in the general case.  That being said, people tend to 
write regexen which match hunks of text from left to right.

So, in theory, it's probably an intractable problem.  But, in practice, 
such a tool would actually be useful in a large set of real-life cases.


From luca.cerone at gmail.com  Fri May 24 10:04:36 2013
From: luca.cerone at gmail.com (Luca Cerone)
Date: Fri, 24 May 2013 07:04:36 -0700 (PDT)
Subject: Piping processes works with 'shell = True' but not otherwise.
Message-ID: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>

Hi everybody, 
I am new to the group (and relatively new to Python)
so I am sorry if this issues has been discussed (although searching for topics in the group I couldn't find a solution to my problem).

I am using Python 2.7.3 to analyse the output of two 3rd parties programs that can be launched in a linux shell as:

 program1 | program2

To do this I have written a function that pipes program1 and program2 (using subprocess.Popen) and the stdout of the subprocess, and a function that parses the output:

A basic example:

from subprocess import Popen, STDOUT, PIPE
def run():
  p1 = Popen(['program1'], stdout = PIPE, stderr = STDOUT)
  p2 = Popen(['program2'], stdin = p1.stdout, stdout = PIPE, stderr = STDOUT)
  p1.stdout.close()
  return p2.stdout


def parse(out):
  for row in out:
    print row
    #do something else with each line
  out.close()
  return parsed_output
   

# main block here

pout = run()

parsed = parse(pout)

#--- END OF PROGRAM ----#

I want to parse the output of 'program1 | program2' line by line because the output is very large.

When running the code above, occasionally some error occurs (IOERROR: [Errno 0]). However this error doesn't occur if I code the run() function as:

def run():
  p = Popen('program1 | program2', shell = True, stderr = STDOUT, stdout = PIPE)
  return p.stdout

I really can't understand why the first version causes errors, while the second one doesn't.

Can you please help me understanding what's the difference between the two cases? 

Thanks a lot in advance for the help,
Cheers, Luca


From luca.cerone at gmail.com  Sun May 26 06:31:51 2013
From: luca.cerone at gmail.com (Luca Cerone)
Date: Sun, 26 May 2013 03:31:51 -0700 (PDT)
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
Message-ID: <53d92a77-14ed-4999-90ac-e1c00f9889d5@googlegroups.com>

> 
> Can you please help me understanding what's the difference between the two cases? 
> 

Hi guys has some of you ideas on what is causing my issue?


From clp2 at rebertia.com  Sun May 26 17:05:19 2013
From: clp2 at rebertia.com (Chris Rebert)
Date: Sun, 26 May 2013 14:05:19 -0700
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
Message-ID: <CAMZYqRQ8QVqViDEGgBGmmFmPrhjB_DkeivOO1kdf+kkYCOwbaQ@mail.gmail.com>

On May 24, 2013 7:06 AM, "Luca Cerone" <luca.cerone at gmail.com> wrote:
>
> Hi everybody,
> I am new to the group (and relatively new to Python)
> so I am sorry if this issues has been discussed (although searching for
topics in the group I couldn't find a solution to my problem).
>
> I am using Python 2.7.3 to analyse the output of two 3rd parties programs
that can be launched in a linux shell as:
>
>  program1 | program2
>
> To do this I have written a function that pipes program1 and program2
(using subprocess.Popen) and the stdout of the subprocess, and a function
that parses the output:
>
> A basic example:
>
> from subprocess import Popen, STDOUT, PIPE
> def run():
>   p1 = Popen(['program1'], stdout = PIPE, stderr = STDOUT)
>   p2 = Popen(['program2'], stdin = p1.stdout, stdout = PIPE, stderr =
STDOUT)

Could you provide the *actual* commands you're using, rather than the
generic "program1" and "program2" placeholders? It's *very* common for
people to get the tokenization of a command line wrong (see the Note box in
http://docs.python.org/2/library/subprocess.html#subprocess.Popen for some
relevant advice).

>   p1.stdout.close()
>   return p2.stdout
>
>
> def parse(out):
>   for row in out:
>     print row
>     #do something else with each line
>   out.close()
>   return parsed_output
>
>
> # main block here
>
> pout = run()
>
> parsed = parse(pout)
>
> #--- END OF PROGRAM ----#
>
> I want to parse the output of 'program1 | program2' line by line because
the output is very large.
>
> When running the code above, occasionally some error occurs (IOERROR:
[Errno 0]).

Could you provide the full & complete error message and exception traceback?

> However this error doesn't occur if I code the run() function as:
>
> def run():
>   p = Popen('program1 | program2', shell = True, stderr = STDOUT, stdout
= PIPE)
>   return p.stdout
>
> I really can't understand why the first version causes errors, while the
second one doesn't.
>
> Can you please help me understanding what's the difference between the
two cases?

One obvious difference between the 2 approaches is that the shell doesn't
redirect the stderr streams of the programs, whereas you /are/ redirecting
the stderrs to stdout in the non-shell version of your code. But this is
unlikely to be causing the error you're currently seeing.

You may also want to provide /dev/null as p1's stdin, out of an abundance
of caution.

Lastly, you may want to consider using a wrapper library such as
http://plumbum.readthedocs.org/en/latest/ , which makes it easier to do
pipelining and other such "fancy" things with subprocesses, while still
avoiding the many perils of the shell.

Cheers,
Chris
--
Be patient; it's Memorial Day weekend.
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From luca.cerone at gmail.com  Sun May 26 19:58:57 2013
From: luca.cerone at gmail.com (Luca Cerone)
Date: Sun, 26 May 2013 16:58:57 -0700 (PDT)
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <mailman.2202.1369602328.3114.python-list@python.org>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
	<mailman.2202.1369602328.3114.python-list@python.org>
Message-ID: <08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>

> Could you provide the *actual* commands you're using, rather than the generic "program1" and "program2" placeholders? It's *very* common for people to get the tokenization of a command line wrong (see the Note box in http://docs.python.org/2/library/subprocess.html#subprocess.Popen for some relevant advice).
> 
Hi Chris, first of all thanks for the help. Unfortunately I can't provide the actual commands because are tools that are not publicly available.
I think I get the tokenization right, though.. the problem is not that the programs don't run.. it is just that sometimes I get that error..

Just to be clear I run the process like:

p = subprocess.Popen(['program1','--opt1','val1',...'--optn','valn'], ... the rest)

which I think is the right way to pass arguments (it works fine for other commands)..

> 
> Could you provide the full & complete error message and exception traceback?
> 
yes, as soon as I get to my work laptop..

> 
> One obvious difference between the 2 approaches is that the shell doesn't redirect the stderr streams of the programs, whereas you /are/ redirecting the stderrs to stdout in the non-shell version of your code. But this is unlikely to be causing the error you're currently seeing.
> 
> 
> You may also want to provide /dev/null as p1's stdin, out of an abundance of caution.
>

I tried to redirect the output to /dev/null using the Popen argument:
'stdin = os.path.devnull' (having imported os of course)..
But this seemed to cause even more troubles...
 
> Lastly, you may want to consider using a wrapper library such as http://plumbum.readthedocs.org/en/latest/ , which makes it easier to do pipelining and other such "fancy" things with subprocesses, while still avoiding the many perils of the shell.
> 
> 
Thanks, I didn't know this library, I'll give it a try.
Though I forgot to mention that I was using the subprocess module, because I want the code to be portable (even though for now if it works in Unix platform is OK).

Thanks a lot for your help,
Cheers,
Luca


From carlosnepomuceno at outlook.com  Sun May 26 20:14:24 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 27 May 2013 03:14:24 +0300
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>,
	<mailman.2202.1369602328.3114.python-list@python.org>,
	<08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
Message-ID: <BLU176-W360E72F2103A9E4742B25BD7960@phx.gbl>

pipes usually consumes disk storage at '/tmp'. Are you sure you have enough room on that filesystem? Make sure no other processes are competing against for that space. Just my 50c because I don't know what's causing Errno 0. I don't even know what are the possible causes of such error. Good luck!

----------------------------------------
> Date: Sun, 26 May 2013 16:58:57 -0700
> Subject: Re: Piping processes works with 'shell = True' but not otherwise.
> From: luca.cerone at gmail.com
> To: python-list at python.org
[...]
> I tried to redirect the output to /dev/null using the Popen argument:
> 'stdin = os.path.devnull' (having imported os of course)..
> But this seemed to cause even more troubles...
>
>> Lastly, you may want to consider using a wrapper library such as http://plumbum.readthedocs.org/en/latest/ , which makes it easier to do pipelining and other such "fancy" things with subprocesses, while still avoiding the many perils of the shell.
>>
>>
> Thanks, I didn't know this library, I'll give it a try.
> Though I forgot to mention that I was using the subprocess module, because I want the code to be portable (even though for now if it works in Unix platform is OK).
>
> Thanks a lot for your help,
> Cheers,
> Luca
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rosuav at gmail.com  Mon May 27 04:28:32 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 18:28:32 +1000
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
	<mailman.2202.1369602328.3114.python-list@python.org>
	<08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
Message-ID: <CAPTjJmqgrzM9atEuq-aj=fv+Upf1ocNVKm8G0LFM=8rfz2vhzQ@mail.gmail.com>

On Mon, May 27, 2013 at 9:58 AM, Luca Cerone <luca.cerone at gmail.com> wrote:
>> Could you provide the *actual* commands you're using, rather than the generic "program1" and "program2" placeholders? It's *very* common for people to get the tokenization of a command line wrong (see the Note box in http://docs.python.org/2/library/subprocess.html#subprocess.Popen for some relevant advice).
>>
> Hi Chris, first of all thanks for the help. Unfortunately I can't provide the actual commands because are tools that are not publicly available.
> I think I get the tokenization right, though.. the problem is not that the programs don't run.. it is just that sometimes I get that error..

Will it violate privacy / NDA to post the command line? Even if we
can't actually replicate your system, we may be able to see something
from the commands given.

ChrisA


From luca.cerone at gmail.com  Mon May 27 07:33:19 2013
From: luca.cerone at gmail.com (Luca Cerone)
Date: Mon, 27 May 2013 04:33:19 -0700 (PDT)
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <mailman.2244.1369643321.3114.python-list@python.org>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
	<mailman.2202.1369602328.3114.python-list@python.org>
	<08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
	<mailman.2244.1369643321.3114.python-list@python.org>
Message-ID: <4fd43d0e-9c72-41d0-8c8d-dbc0d0a50022@googlegroups.com>

> 
> 
> Will it violate privacy / NDA to post the command line? Even if we
> 
> can't actually replicate your system, we may be able to see something
> 
> from the commands given.
> 
> 

Unfortunately yes..


From clp2 at rebertia.com  Wed May 29 13:17:37 2013
From: clp2 at rebertia.com (Chris Rebert)
Date: Wed, 29 May 2013 10:17:37 -0700
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
	<mailman.2202.1369602328.3114.python-list@python.org>
	<08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
Message-ID: <CAMZYqRQNxEq35WjoM=2UdonPcwFAAcHkChFR9z3+Zd2d53S+Jg@mail.gmail.com>

On Sun, May 26, 2013 at 4:58 PM, Luca Cerone <luca.cerone at gmail.com> wrote:
<snip>
> Hi Chris, first of all thanks for the help. Unfortunately I can't provide the actual commands because are tools that are not publicly available.
> I think I get the tokenization right, though.. the problem is not that the programs don't run.. it is just that sometimes I get that error..
>
> Just to be clear I run the process like:
>
> p = subprocess.Popen(['program1','--opt1','val1',...'--optn','valn'], ... the rest)
>
> which I think is the right way to pass arguments (it works fine for other commands)..
<snip>
>> You may also want to provide /dev/null as p1's stdin, out of an abundance of caution.
>
> I tried to redirect the output to /dev/null using the Popen argument:
> 'stdin = os.path.devnull' (having imported os of course)..
> But this seemed to cause even more troubles...

That's because stdin/stdout/stderr take file descriptors or file
objects, not path strings.

Cheers,
Chris


From nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915 at spamschutz.glglgl.de  Wed May 29 13:39:40 2013
From: nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915 at spamschutz.glglgl.de (Thomas Rachel)
Date: Wed, 29 May 2013 19:39:40 +0200
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <mailman.2222.1369613672.3114.python-list@python.org>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>,
	<mailman.2202.1369602328.3114.python-list@python.org>,
	<08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
	<mailman.2222.1369613672.3114.python-list@python.org>
Message-ID: <ko5egs$knk$1@r01.glglgl.de>

Am 27.05.2013 02:14 schrieb Carlos Nepomuceno:
> pipes usually consumes disk storage at '/tmp'.

Good that my pipes don't know about that.

Why should that happen?


Thomas


From carlosnepomuceno at outlook.com  Wed May 29 15:31:05 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 29 May 2013 22:31:05 +0300
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <ko5egs$knk$1@r01.glglgl.de>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>, ,
	<mailman.2202.1369602328.3114.python-list@python.org>, ,
	<08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>,
	<mailman.2222.1369613672.3114.python-list@python.org>,
	<ko5egs$knk$1@r01.glglgl.de>
Message-ID: <BLU176-W389D0394C7CA8C9B19895AD7900@phx.gbl>

----------------------------------------
> From: nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915 at spamschutz.glglgl.de
> Subject: Re: Piping processes works with 'shell = True' but not otherwise.
> Date: Wed, 29 May 2013 19:39:40 +0200
> To: python-list at python.org
>
> Am 27.05.2013 02:14 schrieb Carlos Nepomuceno:
>> pipes usually consumes disk storage at '/tmp'.
>
> Good that my pipes don't know about that.
>
> Why should that happen?
>
>
> Thomas
> --
> http://mail.python.org/mailman/listinfo/python-list

Ooops! My mistake! We've been using 'tee' when in debugging mode and I though that would apply to this case. Nevermind! 		 	   		  

From cs at zip.com.au  Wed May 29 18:18:30 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Thu, 30 May 2013 08:18:30 +1000
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <ko5egs$knk$1@r01.glglgl.de>
References: <ko5egs$knk$1@r01.glglgl.de>
Message-ID: <20130529221830.GA51388@cskk.homeip.net>

On 29May2013 19:39, Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915 at spamschutz.glglgl.de> wrote:
| Am 27.05.2013 02:14 schrieb Carlos Nepomuceno:
| >pipes usually consumes disk storage at '/tmp'.
| 
| Good that my pipes don't know about that.
| Why should that happen?

It probably doesn't on anything modern. On V7 UNIX at least there
was a kernel notion of the "pipe fs", where pipe storage existed;
usually /tmp; using small real (but unnamed) files is an easy way
to implement them, especially on systems where RAM is very small
and without a paging VM - for example, V7 UNIX ran on PDP-11s amongst
other things. And files need a filesystem.

But even then pipes are still small fixed length buffers; they don't
grow without bound as you might have inferred from the quoted
statement.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

ERROR 155 - You can't do that.  - Data General S200 Fortran error code list


From luca.cerone at gmail.com  Fri May 31 05:28:47 2013
From: luca.cerone at gmail.com (Luca Cerone)
Date: Fri, 31 May 2013 02:28:47 -0700 (PDT)
Subject: Piping processes works with 'shell = True' but not otherwise.
In-Reply-To: <mailman.2366.1369847860.3114.python-list@python.org>
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
	<mailman.2202.1369602328.3114.python-list@python.org>
	<08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
	<mailman.2366.1369847860.3114.python-list@python.org>
Message-ID: <8c89fb10-63eb-446c-855b-f4c5406976ea@googlegroups.com>

> 
> That's because stdin/stdout/stderr take file descriptors or file
> 
> objects, not path strings.
> 

Thanks Chris, how do I set the file descriptor to /dev/null then?


From __peter__ at web.de  Fri May 31 05:52:41 2013
From: __peter__ at web.de (Peter Otten)
Date: Fri, 31 May 2013 11:52:41 +0200
Subject: Piping processes works with 'shell = True' but not otherwise.
References: <062f557e-8e1a-4efb-9178-7d685b47a834@googlegroups.com>
	<mailman.2202.1369602328.3114.python-list@python.org>
	<08aa32b7-0fb7-4665-83fa-5cc7ec36f898@googlegroups.com>
	<mailman.2366.1369847860.3114.python-list@python.org>
	<8c89fb10-63eb-446c-855b-f4c5406976ea@googlegroups.com>
Message-ID: <ko9rsm$imp$1@ger.gmane.org>

Luca Cerone wrote:

>> 
>> That's because stdin/stdout/stderr take file descriptors or file
>> 
>> objects, not path strings.
>> 
> 
> Thanks Chris, how do I set the file descriptor to /dev/null then?

For example:

with open(os.devnull, "wb") as stderr:
    p = subprocess.Popen(..., stderr=stderr)
    ...


In Python 3.3 and above:

p = subprocess.Popen(..., stderr=subprocess.DEVNULL)



From logan.c.graham at gmail.com  Fri May 24 13:32:26 2013
From: logan.c.graham at gmail.com (logan.c.graham at gmail.com)
Date: Fri, 24 May 2013 10:32:26 -0700 (PDT)
Subject: Total Beginner - Extracting Data from a Database Online (Screenshot)
Message-ID: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>

Hey guys,

I'm learning Python and I'm experimenting with different projects -- I like learning by doing. I'm wondering if you can help me here:

http://i.imgur.com/KgvSKWk.jpg

What this is is a publicly-accessible webpage that's a simple database of people who have used the website. Ideally what I'd like to end up with is an excel spreadsheet with data from the columns #fb, # vids, fb sent?, # email tm.

I'd like to use Python to do it -- crawl the page and extract the data in a usable way.

I'd love your input! I'm just a learner.


From davea at davea.name  Fri May 24 15:41:27 2013
From: davea at davea.name (Dave Angel)
Date: Fri, 24 May 2013 15:41:27 -0400
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
Message-ID: <519FC267.5050406@davea.name>

On 05/24/2013 01:32 PM, logan.c.graham at gmail.com wrote:
> Hey guys,
>
> I'm learning Python

Welcome.

> and I'm experimenting with different projects -- I like learning by doing. I'm wondering if you can help me here:
>
>na
>
> What this is is a publicly-accessible webpage

No, it's just a jpeg file, an image.

> that's a simple database of people who have used the website. Ideally what I'd like to end up with is an excel spreadsheet with data from the columns #fb, # vids, fb sent?, # email tm.
>
> I'd like to use Python to do it -- crawl the page and extract the data in a usable way.
>

But there's no page to crawl.  You may have to start by finding an ocr 
to interpret the image as characters.  Or find some other source for 
your data.

> I'd love your input! I'm just a learner.
>


-- 
DaveA


From carlosnepomuceno at outlook.com  Fri May 24 19:36:35 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 02:36:35 +0300
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
Message-ID: <BLU176-W146D4B36B065DF7ADFC2E6D7AB0@phx.gbl>

### table_data_extraction.py ###
# Usage: table[id][row][column]
# tables[0]?????? : 1st table
# tables[1][2]??? : 3rd row of 2nd table
# tables[3][4][5] : cell content of 6th column of 5th row of 4th table
# len(table)????? : quantity of tables
# len(table[6])?? : quantity of rows of 7th table
# len(table[7][8]): quantity of columns of 9th row of 8th table

impor re
import urllib2

#to retrieve the contents of the page
page = urllib2.urlopen("http://example.com/page.html").read().strip()

#to create the tables list
tables=[[re.findall('<TD>(.*?)</TD>',r,re.S) for r in re.findall('<TR>(.*?)</TR>',t,re.S)] for t in re.findall('<TABLE>(.*?)</TABLE>',page,re.S)]


Pretty simple. Good luck!

----------------------------------------
> Date: Fri, 24 May 2013 10:32:26 -0700
> Subject: Total Beginner - Extracting Data from a Database Online (Screenshot)
> From: logan.c.graham at gmail.com
> To: python-list at python.org
>
> Hey guys,
>
> I'm learning Python and I'm experimenting with different projects -- I like learning by doing. I'm wondering if you can help me here:
>
> http://i.imgur.com/KgvSKWk.jpg
>
> What this is is a publicly-accessible webpage that's a simple database of people who have used the website. Ideally what I'd like to end up with is an excel spreadsheet with data from the columns #fb, # vids, fb sent?, # email tm.
>
> I'd like to use Python to do it -- crawl the page and extract the data in a usable way.
>
> I'd love your input! I'm just a learner.
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From davea at davea.name  Fri May 24 21:16:37 2013
From: davea at davea.name (Dave Angel)
Date: Fri, 24 May 2013 21:16:37 -0400
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <BLU176-W146D4B36B065DF7ADFC2E6D7AB0@phx.gbl>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
	<BLU176-W146D4B36B065DF7ADFC2E6D7AB0@phx.gbl>
Message-ID: <51A010F5.4020607@davea.name>

On 05/24/2013 07:36 PM, Carlos Nepomuceno wrote:
>
>      <SNIP>
> page = urllib2.urlopen("http://example.com/page.html").read().strip()
>
> #to create the tables list
> tables=[[re.findall('<TD>(.*?)</TD>',r,re.S) for r in re.findall('<TR>(.*?)</TR>',t,re.S)] for t in re.findall('<TABLE>(.*?)</TABLE>',page,re.S)]
>
>
> Pretty simple. Good luck!

Only if the page is html, which the OP's was not. It was an image.  Try 
parsing that with regex.



-- 
DaveA


From rosuav at gmail.com  Fri May 24 23:22:54 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 13:22:54 +1000
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
Message-ID: <CAPTjJmrjWiNE+jc2NvQFjfjqt1d8kPOa=Yhf5TYvZTMq1jXS7Q@mail.gmail.com>

On Sat, May 25, 2013 at 3:32 AM,  <logan.c.graham at gmail.com> wrote:
> http://i.imgur.com/KgvSKWk.jpg
>
> What this is is a publicly-accessible webpage...

If that's a screenshot of something that we'd be able to access
directly, then why not just post a link to the actual thing? More
likely I'm thinking it's NOT publicly accessible, which is why it's
been censored.

ChrisA


From neil.suffield at gmail.com  Sat May 25 06:13:41 2013
From: neil.suffield at gmail.com (neil.suffield at gmail.com)
Date: Sat, 25 May 2013 03:13:41 -0700 (PDT)
Subject: Total Beginner - Extracting Data from a Database Online (Screenshot)
In-Reply-To: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
Message-ID: <d17c7b10-67aa-4fd3-bffc-fbd6dab81d71@googlegroups.com>

If you are talking about accessing a web page, rather than an image, then you want to do what is known as screen scraping. 

One of the best tools for this is called BeautifulSoup.

http://www.crummy.com/software/BeautifulSoup/


From neil.suffield at gmail.com  Sat May 25 06:15:22 2013
From: neil.suffield at gmail.com (neil.suffield at gmail.com)
Date: Sat, 25 May 2013 03:15:22 -0700 (PDT)
Subject: Total Beginner - Extracting Data from a Database Online (Screenshot)
In-Reply-To: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
Message-ID: <29195880-e277-486e-a5dc-77110b093d4e@googlegroups.com>

If you are talking about accessing a web page, rather than an image, then what you want to do is known as 'screen scraping'. 

One of the best tools for this is called BeautifulSoup. 

http://www.crummy.com/software/BeautifulSoup/ 


From logan.c.graham at gmail.com  Sat May 25 20:48:50 2013
From: logan.c.graham at gmail.com (logan.c.graham at gmail.com)
Date: Sat, 25 May 2013 17:48:50 -0700 (PDT)
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <mailman.2099.1369452182.3114.python-list@python.org>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
	<mailman.2099.1369452182.3114.python-list@python.org>
Message-ID: <3126e4b6-d685-4ac8-8532-134f46a904ba@googlegroups.com>

Sorry to be unclear -- it's a screenshot of the webpage, which is publicly accessible, but it contains sensitive information. A bad combination, admittedly, and something that'll be soon fixed.


From john_ladasky at sbcglobal.net  Sat May 25 21:33:25 2013
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Sat, 25 May 2013 18:33:25 -0700 (PDT)
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <mailman.2088.1369438663.3114.python-list@python.org>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
	<mailman.2088.1369438663.3114.python-list@python.org>
Message-ID: <cceeff0e-611b-40eb-83a1-e45c37a4f04e@googlegroups.com>

On Friday, May 24, 2013 4:36:35 PM UTC-7, Carlos Nepomuceno wrote:
> #to create the tables list
> tables=[[re.findall('<TD>(.*?)</TD>',r,re.S) for r in re.findall('<TR>(.*?)</TR>',t,re.S)] for t in re.findall('<TABLE>(.*?)</TABLE>',page,re.S)]
> 
> 
> Pretty simple. 

Two nested list comprehensions, with regex pattern matching?

Logan did say he was a "total beginner."  :^)


From logan.c.graham at gmail.com  Mon May 27 20:58:00 2013
From: logan.c.graham at gmail.com (logan.c.graham at gmail.com)
Date: Mon, 27 May 2013 17:58:00 -0700 (PDT)
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <cceeff0e-611b-40eb-83a1-e45c37a4f04e@googlegroups.com>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
	<mailman.2088.1369438663.3114.python-list@python.org>
	<cceeff0e-611b-40eb-83a1-e45c37a4f04e@googlegroups.com>
Message-ID: <faa2c4de-d033-4a01-a9ab-79189f39867e@googlegroups.com>

On Saturday, May 25, 2013 6:33:25 PM UTC-7, John Ladasky wrote:
> On Friday, May 24, 2013 4:36:35 PM UTC-7, Carlos Nepomuceno wrote:
> 
> > #to create the tables list
> 
> > tables=[[re.findall('<TD>(.*?)</TD>',r,re.S) for r in re.findall('<TR>(.*?)</TR>',t,re.S)] for t in re.findall('<TABLE>(.*?)</TABLE>',page,re.S)]
> 
> > 
> 
> > 
> 
> > Pretty simple. 
> 
> 
> 
> Two nested list comprehensions, with regex pattern matching?
> 
> 
> 
> Logan did say he was a "total beginner."  :^)



Oh goodness, yes, I have no clue.


From carlosnepomuceno at outlook.com  Mon May 27 21:21:07 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 04:21:07 +0300
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <faa2c4de-d033-4a01-a9ab-79189f39867e@googlegroups.com>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>,
	<mailman.2088.1369438663.3114.python-list@python.org>,
	<cceeff0e-611b-40eb-83a1-e45c37a4f04e@googlegroups.com>,
	<faa2c4de-d033-4a01-a9ab-79189f39867e@googlegroups.com>
Message-ID: <BLU176-W4445322DC54B16D286267D7970@phx.gbl>

----------------------------------------
> Date: Mon, 27 May 2013 17:58:00 -0700
> Subject: Re: Total Beginner - Extracting Data from a Database Online (Screenshot)
> From: logan.c.graham at gmail.com
> To: python-list at python.org
[...]
>
> Oh goodness, yes, I have no clue.

For example:

# to retrieve the contents of all column '# fb' (11th column from the image you sent)

c11 = [tables[0][r][10] for r in range(len(tables[0]))]
#????? ----------------??????????????? -------------
#????? this is the content???????????? this is the quantity
#????? of the 11th cell??????????????? of rows in table[0]
#????? of row 'r' 		 	   		  

From pconnell at gmail.com  Tue May 28 02:40:07 2013
From: pconnell at gmail.com (Phil Connell)
Date: Tue, 28 May 2013 07:40:07 +0100
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <BLU176-W4445322DC54B16D286267D7970@phx.gbl>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>
	<mailman.2088.1369438663.3114.python-list@python.org>
	<cceeff0e-611b-40eb-83a1-e45c37a4f04e@googlegroups.com>
	<faa2c4de-d033-4a01-a9ab-79189f39867e@googlegroups.com>
	<BLU176-W4445322DC54B16D286267D7970@phx.gbl>
Message-ID: <CANCy3Mw01WjW9MFK7FPKgB7EM8Z-uvTXpvmDjRW5JG+AAZ+65w@mail.gmail.com>

On 28 May 2013 02:21, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
wrote:
>
> ----------------------------------------
> > Date: Mon, 27 May 2013 17:58:00 -0700
> > Subject: Re: Total Beginner - Extracting Data from a Database Online
(Screenshot)
> > From: logan.c.graham at gmail.com
> > To: python-list at python.org
> [...]
> >
> > Oh goodness, yes, I have no clue.
>
> For example:
>
> # to retrieve the contents of all column '# fb' (11th column from the
image you sent)
>
> c11 = [tables[0][r][10] for r in range(len(tables[0]))]

Or rather:

c11 = [row[10] for row in tables[0]]

In most cases, range(len(x)) is a sign that you're doing it wrong :)
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From carlosnepomuceno at outlook.com  Tue May 28 02:52:10 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 06:52:10 -0000
Subject: Total Beginner - Extracting Data from a Database Online
	(Screenshot)
In-Reply-To: <CANCy3Mw01WjW9MFK7FPKgB7EM8Z-uvTXpvmDjRW5JG+AAZ+65w@mail.gmail.com>
References: <b3730ef1-90bb-4ef4-8683-239e722aa1da@googlegroups.com>,
	<mailman.2088.1369438663.3114.python-list@python.org>,
	<cceeff0e-611b-40eb-83a1-e45c37a4f04e@googlegroups.com>,
	<faa2c4de-d033-4a01-a9ab-79189f39867e@googlegroups.com>,
	<BLU176-W4445322DC54B16D286267D7970@phx.gbl>,
	<CANCy3Mw01WjW9MFK7FPKgB7EM8Z-uvTXpvmDjRW5JG+AAZ+65w@mail.gmail.com>
Message-ID: <BLU176-W44858642C61EA7F6E10A6D7970@phx.gbl>

________________________________
> Date: Tue, 28 May 2013 07:40:07 +0100 
> Subject: RE: Total Beginner - Extracting Data from a Database Online  
> (Screenshot) 
> From: pconnell at gmail.com 
[...]
> > 
> > c11 = [tables[0][r][10] for r in range(len(tables[0]))] 
>  
> Or rather: 
>  
> c11 = [row[10] for row in tables[0]] 
>  
> In most cases, range(len(x)) is a sign that you're doing it wrong :)

Indeed! Much better that way! \o 		 	   		  

From sara.lochtie at gmail.com  Fri May 24 15:58:50 2013
From: sara.lochtie at gmail.com (Sara Lochtie)
Date: Fri, 24 May 2013 12:58:50 -0700 (PDT)
Subject: Plotting with PyQwt
Message-ID: <95315d83-2460-48b2-818f-412a911216cc@googlegroups.com>

Hi,

I'm trying to plot temperature vs. time using Qwt. I have temp data that i get in real time and I want to plot against time. So I thought I would have to use QwtPlot and QwtPlotCurve, so I did this first:

self.tempGraph = Qwt.QwtPlot(self)

curve =  QwtPlotCurve()
curve.setData(x, temp)



x is the time and temp is the data I have collected.

I know this isn't current, but I just don't know how to go about it. I haven't used Qwt before.

If anyone has some tips or advice for me that would be great!




From sara.lochtie at gmail.com  Fri May 24 16:06:42 2013
From: sara.lochtie at gmail.com (Sara Lochtie)
Date: Fri, 24 May 2013 13:06:42 -0700 (PDT)
Subject: Plotting with PyQwt
In-Reply-To: <95315d83-2460-48b2-818f-412a911216cc@googlegroups.com>
References: <95315d83-2460-48b2-818f-412a911216cc@googlegroups.com>
Message-ID: <da37f828-8800-40b4-b84f-774774e83dd5@googlegroups.com>

isn't correct*

On Friday, May 24, 2013 12:58:50 PM UTC-7, Sara Lochtie wrote:
> Hi,
> 
> 
> 
> I'm trying to plot temperature vs. time using Qwt. I have temp data that i get in real time and I want to plot against time. So I thought I would have to use QwtPlot and QwtPlotCurve, so I did this first:
> 
> 
> 
> self.tempGraph = Qwt.QwtPlot(self)
> 
> 
> 
> curve =  QwtPlotCurve()
> 
> curve.setData(x, temp)
> 
> 
> 
> 
> 
> 
> 
> x is the time and temp is the data I have collected.
> 
> 
> 
> I know this isn't current, but I just don't know how to go about it. I haven't used Qwt before.
> 
> 
> 
> If anyone has some tips or advice for me that would be great!



From jcasale at activenetwerx.com  Fri May 24 17:00:01 2013
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Fri, 24 May 2013 21:00:01 +0000
Subject: Ldap module and base64 oncoding
Message-ID: <dc63b80b78aa4027867f06ae10f8c5bb@exch.activenetwerx.com>

I have some data I am working with that is not being interpreted as a string requiring
base64 encoding when sent to the ldif module for output.

The base64 string parsed is ZGV0XDMzMTB3YmJccGc= and the raw string is det\3310wbb\pg.
I'll admit my understanding of the handling requirements of non ascii data in 2.7 is weak
and as such I am failing at adjusting the regex that deduces is the string contains characters
requiring base64 encoding when being output.

Any insight, or nudges in the right direction would be appreciated!
Thanks,
jlc

From carlosnepomuceno at outlook.com  Fri May 24 21:10:18 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 04:10:18 +0300
Subject: Ldap module and base64 oncoding
In-Reply-To: <dc63b80b78aa4027867f06ae10f8c5bb@exch.activenetwerx.com>
References: <dc63b80b78aa4027867f06ae10f8c5bb@exch.activenetwerx.com>
Message-ID: <BLU176-W6DFF254921D99D8816B74D7940@phx.gbl>

Can you give an example of the code you have?

----------------------------------------
> From: jcasale at activenetwerx.com
> To: python-list at python.org
> Subject: Ldap module and base64 oncoding
> Date: Fri, 24 May 2013 21:00:01 +0000
>
> I have some data I am working with that is not being interpreted as a string requiring
> base64 encoding when sent to the ldif module for output.
>
> The base64 string parsed is ZGV0XDMzMTB3YmJccGc= and the raw string is det\3310wbb\pg.
> I'll admit my understanding of the handling requirements of non ascii data in 2.7 is weak
> and as such I am failing at adjusting the regex that deduces is the string contains characters
> requiring base64 encoding when being output.
>
> Any insight, or nudges in the right direction would be appreciated!
> Thanks,
> jlc
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From jcasale at activenetwerx.com  Sat May 25 11:42:14 2013
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Sat, 25 May 2013 15:42:14 +0000
Subject: Ldap module and base64 oncoding
In-Reply-To: <BLU176-W6DFF254921D99D8816B74D7940@phx.gbl>
References: <dc63b80b78aa4027867f06ae10f8c5bb@exch.activenetwerx.com>,
	<BLU176-W6DFF254921D99D8816B74D7940@phx.gbl>
Message-ID: <3cf3b3670ad24416b17fd62c8dbc2e66@exch.activenetwerx.com>

> Can you give an example of the code you have?

I actually just overrode the regex used by the method in the LDIFWriter class to be far more broad
about what it interprets as a safe string. I really need to properly handle reading, manipulating and
writing non ascii data to solve this...

Shame there is no ldap module (with the ldifwriter) in Python 3.
jlc

From michael at stroeder.com  Sun May 26 11:16:28 2013
From: michael at stroeder.com (=?ISO-8859-1?Q?Michael_Str=F6der?=)
Date: Sun, 26 May 2013 17:16:28 +0200
Subject: Ldap module and base64 oncoding
In-Reply-To: <mailman.2138.1369496613.3114.python-list@python.org>
References: <dc63b80b78aa4027867f06ae10f8c5bb@exch.activenetwerx.com>,
	<BLU176-W6DFF254921D99D8816B74D7940@phx.gbl>
	<mailman.2138.1369496613.3114.python-list@python.org>
Message-ID: <knt8of$flb$1@dont-email.me>

Joseph L. Casale wrote:
>> Can you give an example of the code you have?
> 
> I actually just overrode the regex used by the method in the LDIFWriter class to be far more broad
> about what it interprets as a safe string.

Are you sure that you fully understood RFC 2849 before doing this?
Which version of python-ldap are you using?

> I really need to properly handle reading, manipulating and
> writing non ascii data to solve this...

Module ldif in python-ldap does that for you based on RFC 2849.
Without seeing your code using it I cannot tell what's wrong.

> Shame there is no ldap module (with the ldifwriter) in Python 3.

1. The module ldif is stand-alone. So you could easily make it available for
Python 3.

2. "Shame" is the wrong term here. Personally I currently have no requirement
to use Python 3 and I'm quite busy with other things. So contributors are
welcome. But they should be willing to do some serious work giving continous
support - not only a half-baken patch.

Ciao, Michael.



From michael at stroeder.com  Sun May 26 11:07:35 2013
From: michael at stroeder.com (=?ISO-8859-1?Q?Michael_Str=F6der?=)
Date: Sun, 26 May 2013 17:07:35 +0200
Subject: Ldap module and base64 oncoding
In-Reply-To: <mailman.2077.1369429274.3114.python-list@python.org>
References: <mailman.2077.1369429274.3114.python-list@python.org>
Message-ID: <knt87q$cm3$1@dont-email.me>

Joseph L. Casale wrote:
> I have some data I am working with that is not being interpreted as a string requiring
> base64 encoding when sent to the ldif module for output.
> 
> The base64 string parsed is ZGV0XDMzMTB3YmJccGc= and the raw string is det\3310wbb\pg.
> I'll admit my understanding of the handling requirements of non ascii data in 2.7 is weak
> and as such I am failing at adjusting the regex that deduces is the string contains characters
> requiring base64 encoding when being output.

I'm not sure what exactly you're asking for.
Especially "is not being interpreted as a string requiring base64 encoding" is
written without giving the right context.

So I'm just guessing that this might be the usual misunderstandings with use
of base64 in LDIF. Read more about when LDIF requires base64-encoding here:

http://tools.ietf.org/html/rfc2849

To me everything looks right:

Python 2.7.3 (default, Apr 14 2012, 08:58:41) [GCC] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 'ZGV0XDMzMTB3YmJccGc='.decode('base64').decode('utf-8')
u'det\\3310wbb\\pg'
>>>

What do you think is a problem?

Ciao, Michael.



From jcasale at activenetwerx.com  Sun May 26 12:19:57 2013
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Sun, 26 May 2013 16:19:57 +0000
Subject: Ldap module and base64 oncoding
In-Reply-To: <knt87q$cm3$1@dont-email.me>
References: <mailman.2077.1369429274.3114.python-list@python.org>,
	<knt87q$cm3$1@dont-email.me>
Message-ID: <7fe2db0cd580425eaf01ded48e9f7b55@exch.activenetwerx.com>

> I'm not sure what exactly you're asking for.
> Especially "is not being interpreted as a string requiring base64 encoding" is
> written without giving the right context.
> 
> So I'm just guessing that this might be the usual misunderstandings with use
> of base64 in LDIF. Read more about when LDIF requires base64-encoding here:
> 
> http://tools.ietf.org/html/rfc2849
> 
> To me everything looks right:
> 
> Python 2.7.3 (default, Apr 14 2012, 08:58:41) [GCC] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
> >>> 'ZGV0XDMzMTB3YmJccGc='.decode('base64').decode('utf-8')
> u'det\\3310wbb\\pg'
> >>>
> 
> What do you think is a problem?

Michael,
Thanks for the reply. The issues I am sure are in my code, I read the ldif source file and up
with a values such as 'det\3310wbb\pg' after the base64 encoded entries are decoded.

The problem I am having is when I add this to an add/mod entry list and write it back out.
As it does not get re-encoded to base64 the ldif file ends up seeing a text entry with a ^]
character which if I re-read it with the parser it causes the handle method to break midway
through the entry dict and so the last half re-appears disjoint without a dn.

Like I said, I am pretty sure its my poor misunderstanding of decoding and encoding.
I am using the build from http://www.lfd.uci.edu/~gohlke/pythonlibs/ on a windows
2008 r2 server.

I have re-implemented handle to create a cidict holding all the dn/entry's that are parsed as
I then perform some processing such as manipulating attribute values in the entry dict. I
am pretty sure I am breaking things here. The data I am reading is coming from utf-16-le
encoded files and has Unicode characters as the source directory is globally available, being
written to in just about every country.

Is there a process for manipulating/adding data to the entry dict before I write it out that I
should adhere to? For example, if I am adding a new attribute to be composed of part of
another parsed attr for use in a modlist:

  {'customAttr': ['foo.{}.bar'.format(entry['uid'])]}

By looking at the value from above, 'det\3310wbb\pg', I gather the entry dict was parsed
into byte strings. I should have decoded this, where as some of the data is Unicode and
as such I should have encoded it?

I really appreciate the time.

Grazie per tutto,
jlc

From michael at stroeder.com  Sun May 26 15:48:38 2013
From: michael at stroeder.com (=?ISO-8859-1?Q?Michael_Str=F6der?=)
Date: Sun, 26 May 2013 21:48:38 +0200
Subject: Ldap module and base64 oncoding
In-Reply-To: <mailman.2178.1369585225.3114.python-list@python.org>
References: <mailman.2077.1369429274.3114.python-list@python.org>,
	<knt87q$cm3$1@dont-email.me>
	<mailman.2178.1369585225.3114.python-list@python.org>
Message-ID: <kntomp$jsn$1@dont-email.me>

Joseph L. Casale wrote:
>> I'm not sure what exactly you're asking for.
>> Especially "is not being interpreted as a string requiring base64 encoding" is
>> written without giving the right context.
>>
>> So I'm just guessing that this might be the usual misunderstandings with use
>> of base64 in LDIF. Read more about when LDIF requires base64-encoding here:
>>
>> http://tools.ietf.org/html/rfc2849
>>
>> To me everything looks right:
>>
>> Python 2.7.3 (default, Apr 14 2012, 08:58:41) [GCC] on linux2
>> Type "help", "copyright", "credits" or "license" for more information.
>>>>> 'ZGV0XDMzMTB3YmJccGc='.decode('base64').decode('utf-8')
>> u'det\\3310wbb\\pg'
>>>>>
>>
>> What do you think is a problem?
> 
> Thanks for the reply. The issues I am sure are in my code, I read the ldif source file and up
> with a values such as 'det\3310wbb\pg' after the base64 encoded entries are decoded.
> 
> The problem I am having is when I add this to an add/mod entry list and write it back out.
> As it does not get re-encoded to base64 the ldif file ends up seeing a text entry with a ^]
> character which if I re-read it with the parser it causes the handle method to break midway
> through the entry dict and so the last half re-appears disjoint without a dn.
> 
> Like I said, I am pretty sure its my poor misunderstanding of decoding and encoding.
> I am using the build from http://www.lfd.uci.edu/~gohlke/pythonlibs/ on a windows
> 2008 r2 server.
> 
> I have re-implemented handle to create a cidict holding all the dn/entry's that are parsed as
> I then perform some processing such as manipulating attribute values in the entry dict. I
> am pretty sure I am breaking things here. The data I am reading is coming from utf-16-le
> encoded files and has Unicode characters as the source directory is globally available, being
> written to in just about every country.

Processing LDIF is one thing, doing LDAP operations another.

LDIF itself is meant to be ASCII-clean. But each attribute value can carry any
byte sequence (e.g. attribute 'jpegPhoto'). There's no further processing by
module LDIF - it simply returns byte sequences.

The access protocol LDAPv3 mandates UTF-8 encoding for Unicode strings on the
wire if attribute syntax is DirectoryString, IA5String (mainly ASCII) or similar.

So if you're LDIF input returns UTF-16 encoded attribute values for e.g.
attribute 'cn' or 'o' or another attribute not being of OctetString or Binary
syntax something's wrong with the producer of the LDIF data.

> Is there a process for manipulating/adding data to the entry dict before I write it out that I
> should adhere to? For example, if I am adding a new attribute to be composed of part of
> another parsed attr for use in a modlist:
> 
>   {'customAttr': ['foo.{}.bar'.format(entry['uid'])]}
> 
> By looking at the value from above, 'det\3310wbb\pg', I gather the entry dict was parsed
> into byte strings. I should have decoded this, where as some of the data is Unicode and
> as such I should have encoded it?

I wonder what the string really is. At least the base64-encoding you provided
before decodes as UTF-8 but I'm not sure whether it's the right sequence of
Unicode code points you're expecting.

>>> 'ZGV0XDMzMTB3YmJccGc='.decode('base64').decode('utf-8')
u'det\\3310wbb\\pg'

I still can't figure out what you're really doing though. I'd recommend to
strip down your operations to a very simple test code snippet illustrating the
issue and post that here.

Ciao, Michael.



From jcasale at activenetwerx.com  Mon May 27 01:15:01 2013
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 27 May 2013 05:15:01 +0000
Subject: Ldap module and base64 oncoding
In-Reply-To: <kntomp$jsn$1@dont-email.me>
References: <mailman.2077.1369429274.3114.python-list@python.org>,
	<knt87q$cm3$1@dont-email.me>
	<mailman.2178.1369585225.3114.python-list@python.org>,
	<kntomp$jsn$1@dont-email.me>
Message-ID: <78b0eafba002480aba586b54db86abfc@exch.activenetwerx.com>

Hi Michael,

> Processing LDIF is one thing, doing LDAP operations another.
> 
> LDIF itself is meant to be ASCII-clean. But each attribute value can carry any
> byte sequence (e.g. attribute 'jpegPhoto'). There's no further processing by
> module LDIF - it simply returns byte sequences.
> 
> The access protocol LDAPv3 mandates UTF-8 encoding for Unicode strings on the
> wire if attribute syntax is DirectoryString, IA5String (mainly ASCII) or similar.
> 
> So if you're LDIF input returns UTF-16 encoded attribute values for e.g.
> attribute 'cn' or 'o' or another attribute not being of OctetString or Binary
> syntax something's wrong with the producer of the LDIF data.

That could be, I am using ms's ldifde.exe to dump a domino and AD directory for
comparative processing. The problem is I don't have much control on the data in
the directory and I do know that DN's have non ascii characters unique to the

> I wonder what the string really is. At least the base64-encoding you provided
> before decodes as UTF-8 but I'm not sure whether it's the right sequence of
> Unicode code points you're expecting.
> 
> >>> 'ZGV0XDMzMTB3YmJccGc='.decode('base64').decode('utf-8')
> u'det\\3310wbb\\pg'
> 
> I still can't figure out what you're really doing though. I'd recommend to
> strip down your operations to a very simple test code snippet illustrating the
> issue and post that here.

So I have removed all my likely broken attempts at working with this data and will
soon have some simple code but at this point I may have an indication of what is
awry with my data.

After parsing the data for a user I am simply taking a value from the ldif file and writing
it back out to another which fails, the value parsed is:

officestreetaddress:: T3R0by1NZcOfbWVyLVN0cmHDn2UgMQ==


  File "C:\Python27\lib\site-packages\ldif.py", line 202, in unparse
    self._unparseChangeRecord(record)
  File "C:\Python27\lib\site-packages\ldif.py", line 181, in _unparseChangeRecord
    self._unparseAttrTypeandValue(mod_type,mod_val)
  File "C:\Python27\lib\site-packages\ldif.py", line 142, in _unparseAttrTypeandValue
    self._unfoldLDIFLine(':: '.join([attr_type,base64.encodestring(attr_value).replace('\n','')]))
  File "C:\Python27\lib\base64.py", line 315, in encodestring
    pieces.append(binascii.b2a_base64(chunk))
UnicodeEncodeError: 'ascii' codec can't encode character u'\xdf' in position 7: ordinal not in range(128)

> c:\python27\lib\base64.py(315)encodestring()
-> pieces.append(binascii.b2a_base64(chunk))
(Pdb) l
310     def encodestring(s):
311         """Encode a string into multiple lines of base-64 data."""
312         pieces = []
313         for i in range(0, len(s), MAXBINSIZE):
314             chunk = s[i : i + MAXBINSIZE]
315  ->         pieces.append(binascii.b2a_base64(chunk))
316         return "".join(pieces)
317
318
319     def decodestring(s):
320         """Decode a string."""
(Pdb) args
s = Otto-Me?mer-Stra?e 1

So moving up a frame or two and looking at the entry dict, I see a modlist entry of:
('streetAddress', [u'Otto-Me\xdfmer-Stra\xdfe 1']) which is correct:

In [2]: 'T3R0by1NZcOfbWVyLVN0cmHDn2UgMQ=='.decode('base64').decode('utf-8')
Out[2]: u'Otto-Me\xdfmer-Stra\xdfe 1'

Looking at the stack trace, I think I see the issue:
(Pdb) import base64
(Pdb) base64.encodestring(u'Otto-Me\xdfmer-Stra\xdfe 1'.encode('utf-8')).replace('\n','')
'T3R0by1NZcOfbWVyLVN0cmHDn2UgMQ=='

I now have the exact the value I started with. Ensuring where I ever handle the original
values that I return utf-8 decoded objects for use in a modlist to later write and Sub
classing LDIFWriter and overriding _unparseAttrTypeandValue to do the encoding has
eliminated all the errors.

What remains finally is ldifde.exe's output of what looks like U+00BF, or an inverted question
mark for some values, otherwise this issue looks solved.

Thanks for everything,
jlc





From dieter at handshake.de  Mon May 27 02:04:16 2013
From: dieter at handshake.de (dieter)
Date: Mon, 27 May 2013 08:04:16 +0200
Subject: Ldap module and base64 oncoding
References: <mailman.2077.1369429274.3114.python-list@python.org>
	<knt87q$cm3$1@dont-email.me>
	<mailman.2178.1369585225.3114.python-list@python.org>
	<kntomp$jsn$1@dont-email.me>
	<78b0eafba002480aba586b54db86abfc@exch.activenetwerx.com>
Message-ID: <87ppwdot5r.fsf@handshake.de>

"Joseph L. Casale" <jcasale at activenetwerx.com> writes:
> ...
> After parsing the data for a user I am simply taking a value from the ldif file and writing
> it back out to another which fails, the value parsed is:
>
> officestreetaddress:: T3R0by1NZcOfbWVyLVN0cmHDn2UgMQ==
>
>
>   File "C:\Python27\lib\site-packages\ldif.py", line 202, in unparse
>     self._unparseChangeRecord(record)
>   File "C:\Python27\lib\site-packages\ldif.py", line 181, in _unparseChangeRecord
>     self._unparseAttrTypeandValue(mod_type,mod_val)
>   File "C:\Python27\lib\site-packages\ldif.py", line 142, in _unparseAttrTypeandValue
>     self._unfoldLDIFLine(':: '.join([attr_type,base64.encodestring(attr_value).replace('\n','')]))
>   File "C:\Python27\lib\base64.py", line 315, in encodestring
>     pieces.append(binascii.b2a_base64(chunk))
> UnicodeEncodeError: 'ascii' codec can't encode character u'\xdf' in position 7: ordinal not in range(128)
>
>> c:\python27\lib\base64.py(315)encodestring()
> -> pieces.append(binascii.b2a_base64(chunk))

This looks like a coding bug: "chunk" seems to be a unicode string;
"b2a_base64" expects an encoded string ("str/bytes"); as
a consequence, Python tries to convert the unicode to "str" by
encoding with its "default enconding" ("ascii" by default) - and
fails.

You could try to find out, why "chunk" is unicode (rather than "str").
That will probably bring you to the real problem.



From michael at stroeder.com  Mon May 27 03:56:43 2013
From: michael at stroeder.com (=?ISO-8859-1?Q?Michael_Str=F6der?=)
Date: Mon, 27 May 2013 09:56:43 +0200
Subject: Ldap module and base64 oncoding
In-Reply-To: <mailman.2231.1369631792.3114.python-list@python.org>
References: <mailman.2077.1369429274.3114.python-list@python.org>,
	<knt87q$cm3$1@dont-email.me>
	<mailman.2178.1369585225.3114.python-list@python.org>,
	<kntomp$jsn$1@dont-email.me>
	<mailman.2231.1369631792.3114.python-list@python.org>
Message-ID: <knv3bs$b47$1@dont-email.me>

Joseph L. Casale wrote:
> After parsing the data for a user I am simply taking a value from the ldif file and writing
> it back out to another which fails, the value parsed is:
> 
> officestreetaddress:: T3R0by1NZcOfbWVyLVN0cmHDn2UgMQ==
> 
> 
>   File "C:\Python27\lib\site-packages\ldif.py", line 202, in unparse
>     self._unparseChangeRecord(record)
>   File "C:\Python27\lib\site-packages\ldif.py", line 181, in _unparseChangeRecord
>     self._unparseAttrTypeandValue(mod_type,mod_val)
>   File "C:\Python27\lib\site-packages\ldif.py", line 142, in _unparseAttrTypeandValue
>     self._unfoldLDIFLine(':: '.join([attr_type,base64.encodestring(attr_value).replace('\n','')]))
>   File "C:\Python27\lib\base64.py", line 315, in encodestring
>     pieces.append(binascii.b2a_base64(chunk))
> UnicodeEncodeError: 'ascii' codec can't encode character u'\xdf' in position 7: ordinal not in range(128)

Note that all modules in python-ldap up to 2.4.10 including module 'ldif'
expect raw byte strings to be passed as arguments. It seems to me you're
passing a Unicode object in the entry dictionary which will fail in case an
attribute value contains NON-ASCII chars.

python-ldap expects raw strings since it's not schema-aware and therefore does
not have any knowledge about the LDAP syntax used for a particular attribute
type. So automagically convert Unicode strings will likely fail in many cases.
=> The calling application has to deal with it.

> I now have the exact the value I started with. Ensuring where I ever handle the original
> values that I return utf-8 decoded objects for use in a modlist to later write and Sub
> classing LDIFWriter and overriding _unparseAttrTypeandValue to do the encoding has
> eliminated all the errors.

Don't muck with overriding  _unparseAttrTypeandValue(). Simply pass the
properly encoded data into ldif module.

Ciao, Michael.



From jcasale at activenetwerx.com  Mon May 27 20:12:58 2013
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Tue, 28 May 2013 00:12:58 +0000
Subject: Ldap module and base64 oncoding
In-Reply-To: <knv3bs$b47$1@dont-email.me>
References: <mailman.2077.1369429274.3114.python-list@python.org>,
	<knt87q$cm3$1@dont-email.me>
	<mailman.2178.1369585225.3114.python-list@python.org>,
	<kntomp$jsn$1@dont-email.me>
	<mailman.2231.1369631792.3114.python-list@python.org>,
	<knv3bs$b47$1@dont-email.me>
Message-ID: <e603c89dc7e04b2e9771892843245fc6@exch.activenetwerx.com>

> Note that all modules in python-ldap up to 2.4.10 including module 'ldif'
> expect raw byte strings to be passed as arguments. It seems to me you're
> passing a Unicode object in the entry dictionary which will fail in case an
> attribute value contains NON-ASCII chars.

Yup, I was.

> python-ldap expects raw strings since it's not schema-aware and therefore does
> not have any knowledge about the LDAP syntax used for a particular attribute
> type. So automagically convert Unicode strings will likely fail in many cases.
> => The calling application has to deal with it.

I see, that recco went a long a way in cleaning up my code actually and making the
handling of decoding and encoding more consistent.

> Don't muck with overriding  _unparseAttrTypeandValue(). Simply pass the
> properly encoded data into ldif module.

I had some time today, so I attempted to open the ldif files in binary mode to simply
work with the raw byte strings but the moment the first entry was parsed, parse()
stumbled on a character in the first entries dict and passed a dn of None for the last half?

If the option to avoid worrying about decoding and encoding could work, I would be
happy to process the whole lot in byte strings. Any idea what may cause this?

Thanks a lot Michael,
jlc

From michael at stroeder.com  Tue May 28 03:45:32 2013
From: michael at stroeder.com (=?ISO-8859-1?Q?Michael_Str=F6der?=)
Date: Tue, 28 May 2013 09:45:32 +0200
Subject: Ldap module and base64 oncoding
In-Reply-To: <mailman.2269.1369699988.3114.python-list@python.org>
References: <mailman.2077.1369429274.3114.python-list@python.org>,
	<knt87q$cm3$1@dont-email.me>
	<mailman.2178.1369585225.3114.python-list@python.org>,
	<kntomp$jsn$1@dont-email.me>
	<mailman.2231.1369631792.3114.python-list@python.org>,
	<knv3bs$b47$1@dont-email.me>
	<mailman.2269.1369699988.3114.python-list@python.org>
Message-ID: <ko1n2s$a5c$1@dont-email.me>

Joseph L. Casale wrote:
> I had some time today, so I attempted to open the ldif files in binary mode to simply
> work with the raw byte strings but the moment the first entry was parsed, parse()
> stumbled on a character in the first entries dict and passed a dn of None for the last half?

Without seeing the LDIF data and your code I can't tell what's going on.

> If the option to avoid worrying about decoding and encoding could work, I would be
> happy to process the whole lot in byte strings. Any idea what may cause this?

I would not claim that module 'ldif' has really awesome docs.
But did you follow the example with LDIFParser in the docs?

http://www.python-ldap.org/doc/html/ldif.html#example

It illustrates that for LDIF stream processing one basically derives a class
from ldif.LDIFParser overriding method handle(). The most basic test would be
something like this:

[..]
   def handle(self,dn,entry):
     print '***dn',repr(dn)
     pprint.pprint(entry)

And then carefully look at the output.

Ciao, Michael.



From thomasmurphymusic at gmail.com  Fri May 24 18:53:52 2013
From: thomasmurphymusic at gmail.com (Thomas Murphy)
Date: Fri, 24 May 2013 18:53:52 -0400
Subject: Prepending string "@" to usernames
Message-ID: <CAEcwjcx6WtUMTg=QpqjEZ3fyfUhOLWQ2v-pF4qQ9ypFd3DtByA@mail.gmail.com>

Hi beloved list,

I'm having a dumb and SO doesn't seem to have this one answered. I was
sent a long list of instagram usernames to tag for a nightlife
announcement in this format(not real names(i hope))

cookielover93
TheGermanHatesSaurkraut
WhatsThatBoy932834

I'd like to turn this raw text into a list and prepend the @ symbol to
the front of each one, so they're good to go for pasting without me
having to manually add the @ to each one.

Here's where I got to:


raw_address = "cookielover93 TheGermanHatesSaurkraut WhatsThatBoy932834"
address_library = [raw_address.split()]
print address_library

for address in address_library:
    final_address = "@" + str(address)
print final_address


However my output is:

[['cookielover93', 'TheGermanHatesSaurkraut', 'WhatsThatBoy932834']]
@['cookielover93', 'TheGermanHatesSaurkraut', 'WhatsThatBoy932834']


I know I'm iterating wrong. May I ask how?

--
Sincerely,
Thomas Murphy
Code Ninja
646.957.6115


From drsalists at gmail.com  Fri May 24 19:00:22 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Fri, 24 May 2013 16:00:22 -0700
Subject: Prepending string "@" to usernames
In-Reply-To: <CAEcwjcx6WtUMTg=QpqjEZ3fyfUhOLWQ2v-pF4qQ9ypFd3DtByA@mail.gmail.com>
References: <CAEcwjcx6WtUMTg=QpqjEZ3fyfUhOLWQ2v-pF4qQ9ypFd3DtByA@mail.gmail.com>
Message-ID: <CAGGBd_okY709NyG0BBZSHzv709oTAUNbicMgfOMjo3LjFDipwQ@mail.gmail.com>

On Fri, May 24, 2013 at 3:53 PM, Thomas Murphy
<thomasmurphymusic at gmail.com>wrote:

> Hi beloved list,
>
> I'm having a dumb and SO doesn't seem to have this one answered. I was
> sent a long list of instagram usernames to tag for a nightlife
> announcement in this format(not real names(i hope))
>
> cookielover93
> TheGermanHatesSaurkraut
> WhatsThatBoy932834
>
> I'd like to turn this raw text into a list and prepend the @ symbol to
> the front of each one, so they're good to go for pasting without me
> having to manually add the @ to each one.
>
> Here's where I got to:
>
>
> raw_address = "cookielover93 TheGermanHatesSaurkraut WhatsThatBoy932834"
> address_library = [raw_address.split()]
> print address_library
>
> for address in address_library:
>     final_address = "@" + str(address)
> print final_address
>
>
> However my output is:
>
> [['cookielover93', 'TheGermanHatesSaurkraut', 'WhatsThatBoy932834']]
> @['cookielover93', 'TheGermanHatesSaurkraut', 'WhatsThatBoy932834']
>
>
> I know I'm iterating wrong. May I ask how?
>
> --
> Sincerely,
> Thomas Murphy
> Code Ninja
> 646.957.6115
> --
> http://mail.python.org/mailman/listinfo/python-list
>

Maybe this is what you're looking for?

raw_address = "cookielover93 TheGermanHatesSaurkraut WhatsThatBoy932834"
address_library = raw_address.split()
print address_library

final_address = []
for address in address_library:
    final_address.append("@" + str(address))
print final_address
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From thomasmurphymusic at gmail.com  Fri May 24 19:04:31 2013
From: thomasmurphymusic at gmail.com (Thomas Murphy)
Date: Fri, 24 May 2013 19:04:31 -0400
Subject: Prepending string "@" to usernames
In-Reply-To: <CAGGBd_okY709NyG0BBZSHzv709oTAUNbicMgfOMjo3LjFDipwQ@mail.gmail.com>
References: <CAEcwjcx6WtUMTg=QpqjEZ3fyfUhOLWQ2v-pF4qQ9ypFd3DtByA@mail.gmail.com>
	<CAGGBd_okY709NyG0BBZSHzv709oTAUNbicMgfOMjo3LjFDipwQ@mail.gmail.com>
Message-ID: <CAEcwjcyFYMg6sxND7XE6cKOkab3HB2nA89CBJLp2Cq9g5F3h-A@mail.gmail.com>

> Maybe this is what you're looking for?
>
> raw_address = "cookielover93 TheGermanHatesSaurkraut WhatsThatBoy932834"
> address_library = raw_address.split()
> print address_library
>
> final_address = []
> for address in address_library:
>     final_address.append("@" + str(address))
> print final_address
>
Exactly it. Thank you so much Dan. Perfect!



--
Sincerely,
Thomas Murphy
Code Ninja
646.957.6115


From breamoreboy at yahoo.co.uk  Fri May 24 19:16:34 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 25 May 2013 00:16:34 +0100
Subject: Prepending string "@" to usernames
In-Reply-To: <CAEcwjcyFYMg6sxND7XE6cKOkab3HB2nA89CBJLp2Cq9g5F3h-A@mail.gmail.com>
References: <CAEcwjcx6WtUMTg=QpqjEZ3fyfUhOLWQ2v-pF4qQ9ypFd3DtByA@mail.gmail.com>
	<CAGGBd_okY709NyG0BBZSHzv709oTAUNbicMgfOMjo3LjFDipwQ@mail.gmail.com>
	<CAEcwjcyFYMg6sxND7XE6cKOkab3HB2nA89CBJLp2Cq9g5F3h-A@mail.gmail.com>
Message-ID: <knosc1$8ev$1@ger.gmane.org>

On 25/05/2013 00:04, Thomas Murphy wrote:
>> Maybe this is what you're looking for?
>>
>> raw_address = "cookielover93 TheGermanHatesSaurkraut WhatsThatBoy932834"
>> address_library = raw_address.split()
>> print address_library
>>
>> final_address = []
>> for address in address_library:
>>      final_address.append("@" + str(address))
>> print final_address
>>
> Exactly it. Thank you so much Dan. Perfect!
>
>
>
> --
> Sincerely,
> Thomas Murphy
> Code Ninja
> 646.957.6115
>

You can safely remove the call to str as address is already a string.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From python.list at tim.thechases.com  Fri May 24 19:19:40 2013
From: python.list at tim.thechases.com (Tim Chase)
Date: Fri, 24 May 2013 18:19:40 -0500
Subject: Prepending string "@" to usernames
In-Reply-To: <CAEcwjcyFYMg6sxND7XE6cKOkab3HB2nA89CBJLp2Cq9g5F3h-A@mail.gmail.com>
References: <CAEcwjcx6WtUMTg=QpqjEZ3fyfUhOLWQ2v-pF4qQ9ypFd3DtByA@mail.gmail.com>
	<CAGGBd_okY709NyG0BBZSHzv709oTAUNbicMgfOMjo3LjFDipwQ@mail.gmail.com>
	<CAEcwjcyFYMg6sxND7XE6cKOkab3HB2nA89CBJLp2Cq9g5F3h-A@mail.gmail.com>
Message-ID: <20130524181940.620d18ad@bigbox.christie.dr>

On 2013-05-24 19:04, Thomas Murphy wrote:
>> raw_address = "cookielover93 TheGermanHatesSaurkraut
>> WhatsThatBoy932834" address_library = raw_address.split()
>> print address_library
>>
>> final_address = []
>> for address in address_library:
>>     final_address.append("@" + str(address))
>> print final_address
>>
> Exactly it. Thank you so much Dan. Perfect!

Which can be tidily written as a list comprehension:

  final_address = ['@' + address for address in raw_address.split()]

-tkc




From thomasmurphymusic at gmail.com  Fri May 24 20:02:23 2013
From: thomasmurphymusic at gmail.com (Thomas Murphy)
Date: Fri, 24 May 2013 20:02:23 -0400
Subject: Prepending string "@" to usernames
In-Reply-To: <20130524181940.620d18ad@bigbox.christie.dr>
References: <CAEcwjcx6WtUMTg=QpqjEZ3fyfUhOLWQ2v-pF4qQ9ypFd3DtByA@mail.gmail.com>
	<CAGGBd_okY709NyG0BBZSHzv709oTAUNbicMgfOMjo3LjFDipwQ@mail.gmail.com>
	<CAEcwjcyFYMg6sxND7XE6cKOkab3HB2nA89CBJLp2Cq9g5F3h-A@mail.gmail.com>
	<20130524181940.620d18ad@bigbox.christie.dr>
Message-ID: <CAEcwjcyj+TefvqjHNU0R8-00uZ+iHAKa8hDp6fJxFoBfDrQTgA@mail.gmail.com>

> Which can be tidily written as a list comprehension:
>
>   final_address = ['@' + address for address in raw_address.split()]
>
> -tkc
>
>
Ah! Thanks Tim?that tidiness is something I'm trying to head towards
in my own code. I'm trying to transition from the need to visually
write every little step out and write in these more powerful chunks.


--
Sincerely,
Thomas Murphy
Code Ninja
646.957.6115


From bahamutzero8825 at gmail.com  Fri May 24 19:14:27 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Fri, 24 May 2013 18:14:27 -0500
Subject: Prepending string "@" to usernames
In-Reply-To: <CAEcwjcx6WtUMTg=QpqjEZ3fyfUhOLWQ2v-pF4qQ9ypFd3DtByA@mail.gmail.com>
References: <CAEcwjcx6WtUMTg=QpqjEZ3fyfUhOLWQ2v-pF4qQ9ypFd3DtByA@mail.gmail.com>
Message-ID: <519FF453.9080207@gmail.com>

On 2013.05.24 17:53, Thomas Murphy wrote:
> I know I'm iterating wrong. May I ask how?
.split() already returns a list, so instead of iterating over the list and getting a single username, you iterate over the list and get a
single list.
-- 
CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1


From orgnut at yahoo.com  Fri May 24 23:24:00 2013
From: orgnut at yahoo.com (Larry Hudson)
Date: Fri, 24 May 2013 20:24:00 -0700
Subject: Prepending string "@" to usernames
In-Reply-To: <mailman.2081.1369436041.3114.python-list@python.org>
References: <mailman.2081.1369436041.3114.python-list@python.org>
Message-ID: <F-ydnVRrS4tMsz3MnZ2dnUVZ_sudnZ2d@giganews.com>

On 05/24/2013 03:53 PM, Thomas Murphy wrote:

<snip>

> Here's where I got to:
>
>
> raw_address = "cookielover93 TheGermanHatesSaurkraut WhatsThatBoy932834"
> address_library = [raw_address.split()]
> print address_library
>
> for address in address_library:
>      final_address = "@" + str(address)
> print final_address
>
>
> However my output is:
>
> [['cookielover93', 'TheGermanHatesSaurkraut', 'WhatsThatBoy932834']]
> @['cookielover93', 'TheGermanHatesSaurkraut', 'WhatsThatBoy932834']
>
>
> I know I'm iterating wrong. May I ask how?
>
> --
> Sincerely,
> Thomas Murphy
> Code Ninja
> 646.957.6115
>

No, you're not iterating wrong, but you do have two errors:

1:  split() returns a list.  You are putting this list (as a single element) inside a list. 
Drop the square brackets.  Make it:  address_library = raw_address.split()

2:  In your for loop, you want the print _inside_ the loop not outside.  IOW, indent the print 
line.  The way you have it written it will only print the _last_ string.

      -=- Larry -=-



From drsalists at gmail.com  Fri May 24 19:05:51 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Fri, 24 May 2013 16:05:51 -0700
Subject: Survey of Python-in-browser technologies
Message-ID: <CAGGBd_r=xyfLDsk30NNoywQqJBOmDw2L3BXSCjp=vO6k-ALQDA@mail.gmail.com>

I'm putting together a spreadsheet about Python-in-the-browser technologies
for my local python user group.

I've been hitting the mailing lists for the various implementations
already, but I thought I should run it by people here at least once.

Anyway, here it is:

http://stromberg.dnsalias.org/~strombrg/pybrowser/python-browser.html

If you see something inaccurate or omitted, please let me know.
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From carlosnepomuceno at outlook.com  Fri May 24 19:43:02 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 02:43:02 +0300
Subject: Survey of Python-in-browser technologies
In-Reply-To: <CAGGBd_r=xyfLDsk30NNoywQqJBOmDw2L3BXSCjp=vO6k-ALQDA@mail.gmail.com>
References: <CAGGBd_r=xyfLDsk30NNoywQqJBOmDw2L3BXSCjp=vO6k-ALQDA@mail.gmail.com>
Message-ID: <BLU176-W44F92487804B7791EB0AB5D7AB0@phx.gbl>

Thanks Dan! All of that is relevant but I'm specially concerned about security issues and think another column for that purpose would improve your database, although I'm not sure if there's data available or how it would be presented.

________________________________
> Date: Fri, 24 May 2013 16:05:51 -0700 
> Subject: Survey of Python-in-browser technologies 
> From: drsalists at gmail.com 
> To: python-list at python.org 
>  
>  
> I'm putting together a spreadsheet about Python-in-the-browser  
> technologies for my local python user group. 
>  
> I've been hitting the mailing lists for the various implementations  
> already, but I thought I should run it by people here at least once. 
>  
> Anyway, here it is: 
>  
> http://stromberg.dnsalias.org/~strombrg/pybrowser/python-browser.html 
>  
> If you see something inaccurate or omitted, please let me know. 
>  
>  
> -- http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From drsalists at gmail.com  Fri May 24 20:11:18 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Fri, 24 May 2013 17:11:18 -0700
Subject: Survey of Python-in-browser technologies
In-Reply-To: <BLU176-W44F92487804B7791EB0AB5D7AB0@phx.gbl>
References: <CAGGBd_r=xyfLDsk30NNoywQqJBOmDw2L3BXSCjp=vO6k-ALQDA@mail.gmail.com>
	<BLU176-W44F92487804B7791EB0AB5D7AB0@phx.gbl>
Message-ID: <CAGGBd_qZzrB0YhcZXUsn=LQ4EfavfCjBgO7Kmr5FfOO+P95HGg@mail.gmail.com>

Security is an important topic... but I'm not sure how I could gather info
about the security of these implementations.  Still, it's an idea worth at
least keeping in the back of my mind.

On Fri, May 24, 2013 at 4:43 PM, Carlos Nepomuceno <
carlosnepomuceno at outlook.com> wrote:

> Thanks Dan! All of that is relevant but I'm specially concerned about
> security issues and think another column for that purpose would improve
> your database, although I'm not sure if there's data available or how it
> would be presented.
>
> ________________________________
> > Date: Fri, 24 May 2013 16:05:51 -0700
> > Subject: Survey of Python-in-browser technologies
> > From: drsalists at gmail.com
> > To: python-list at python.org
> >
> >
> > I'm putting together a spreadsheet about Python-in-the-browser
> > technologies for my local python user group.
> >
> > I've been hitting the mailing lists for the various implementations
> > already, but I thought I should run it by people here at least once.
> >
> > Anyway, here it is:
> >
> > http://stromberg.dnsalias.org/~strombrg/pybrowser/python-browser.html
> >
> > If you see something inaccurate or omitted, please let me know.
> >
> >
> > -- http://mail.python.org/mailman/listinfo/python-list
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From carlosnepomuceno at outlook.com  Fri May 24 20:38:10 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 03:38:10 +0300
Subject: Survey of Python-in-browser technologies
In-Reply-To: <CAGGBd_qZzrB0YhcZXUsn=LQ4EfavfCjBgO7Kmr5FfOO+P95HGg@mail.gmail.com>
References: <CAGGBd_r=xyfLDsk30NNoywQqJBOmDw2L3BXSCjp=vO6k-ALQDA@mail.gmail.com>,
	<BLU176-W44F92487804B7791EB0AB5D7AB0@phx.gbl>,
	<CAGGBd_qZzrB0YhcZXUsn=LQ4EfavfCjBgO7Kmr5FfOO+P95HGg@mail.gmail.com>
Message-ID: <BLU176-W10CFA75E2D9011EFCAA12BD7940@phx.gbl>

________________________________
> Date: Fri, 24 May 2013 17:11:18 -0700 
> Subject: Re: Survey of Python-in-browser technologies 
> From: drsalists at gmail.com 
> To: carlosnepomuceno at outlook.com 
> CC: python-list at python.org 
>  
>  
> Security is an important topic... but I'm not sure how I could gather  
> info about the security of these implementations.  Still, it's an idea  
> worth at least keeping in the back of my mind. 

Security specialists opinions and facts about known vulnerabilities would be a start, although it may be time consuming to gather all data.

Just a thought! ;) 		 	   		  

From davea at davea.name  Fri May 24 21:29:21 2013
From: davea at davea.name (Dave Angel)
Date: Sat, 25 May 2013 01:29:21 -0000
Subject: Survey of Python-in-browser technologies
In-Reply-To: <BLU176-W10CFA75E2D9011EFCAA12BD7940@phx.gbl>
References: <CAGGBd_r=xyfLDsk30NNoywQqJBOmDw2L3BXSCjp=vO6k-ALQDA@mail.gmail.com>,
	<BLU176-W44F92487804B7791EB0AB5D7AB0@phx.gbl>,
	<CAGGBd_qZzrB0YhcZXUsn=LQ4EfavfCjBgO7Kmr5FfOO+P95HGg@mail.gmail.com>
	<BLU176-W10CFA75E2D9011EFCAA12BD7940@phx.gbl>
Message-ID: <51A012AF.6040003@davea.name>

On 05/24/2013 08:38 PM, Carlos Nepomuceno wrote:
> ________________________________
>> Date: Fri, 24 May 2013 17:11:18 -0700
>> Subject: Re: Survey of Python-in-browser technologies
>> From: drsalists at gmail.com
>> To: carlosnepomuceno at outlook.com
>> CC: python-list at python.org
>>
>>
>> Security is an important topic... but I'm not sure how I could gather
>> info about the security of these implementations.  Still, it's an idea
>> worth at least keeping in the back of my mind.
>
> Security specialists opinions and facts about known vulnerabilities would be a start, although it may be time consuming to gather all data.
>
> Just a thought! ;) 		 	   		
>

Thank you for putting your response after the part you're quoting.  And 
for trimming out the irrelevant parts.

-- 
DaveA


From yoursurrogategod at gmail.com  Fri May 24 20:59:22 2013
From: yoursurrogategod at gmail.com (Yves S. Garret)
Date: Fri, 24 May 2013 20:59:22 -0400
Subject: Why won't Python 2/3 compile when I have valgrind installed?
Message-ID: <CAJ=2b07-6Pe2gJ_bC3180TOZ_UYDOL+cNR2i9BD8ePS2nH0iDg@mail.gmail.com>

This isn't a huge issue, but I'm wondering.  I'm running
Mac OS X, I tried to configure with --with-valgrind and
this is the error that I got:

configure: error: Valgrind support requested but headers not available

Now, I have valgrind installed, so it should work, yes?
If someone has any extra info on this, I'd appreciate it.
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From carlosnepomuceno at outlook.com  Fri May 24 21:07:33 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 04:07:33 +0300
Subject: Why won't Python 2/3 compile when I have valgrind installed?
In-Reply-To: <CAJ=2b07-6Pe2gJ_bC3180TOZ_UYDOL+cNR2i9BD8ePS2nH0iDg@mail.gmail.com>
References: <CAJ=2b07-6Pe2gJ_bC3180TOZ_UYDOL+cNR2i9BD8ePS2nH0iDg@mail.gmail.com>
Message-ID: <BLU176-W381B4A1E4A0132D9B5604ED7940@phx.gbl>

You probably need 'valgrind-devel' package installed.

________________________________
> Date: Fri, 24 May 2013 20:59:22 -0400 
> Subject: Why won't Python 2/3 compile when I have valgrind installed? 
> From: yoursurrogategod at gmail.com 
> To: python-list at python.org 
>  
> This isn't a huge issue, but I'm wondering.  I'm running 
> Mac OS X, I tried to configure with --with-valgrind and 
> this is the error that I got: 
>  
> configure: error: Valgrind support requested but headers not available 
>  
> Now, I have valgrind installed, so it should work, yes? 
> If someone has any extra info on this, I'd appreciate it. 
>  
> -- http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From carlosnepomuceno at outlook.com  Fri May 24 22:08:36 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 05:08:36 +0300
Subject: Is python.org powered by CPython?
Message-ID: <BLU176-W964412BFD2E5188E8078BD7940@phx.gbl>

Is python.org powered by CPython?

Is it using WSGI?

What Python version is been used?

I already checked it's using Apache. Is it using mod_wsgi?

Thanks in advance. 		 	   		  

From nad at acm.org  Fri May 24 22:58:12 2013
From: nad at acm.org (Ned Deily)
Date: Fri, 24 May 2013 19:58:12 -0700
Subject: Is python.org powered by CPython?
References: <BLU176-W964412BFD2E5188E8078BD7940@phx.gbl>
Message-ID: <nad-289F3A.19581224052013@news.gmane.org>

In article <BLU176-W964412BFD2E5188E8078BD7940 at phx.gbl>,
 Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> Is python.org powered by CPython?

Like many websites, the python.org domain consists of a number of 
subdomains with several different webservers on various hosts.  AFAIK, 
the main www.python.org server is currently all (or mainly) static 
content served by Apache, although the static files are, in part, 
generated by a home-grown content management system powered by CPython.  
I'm not sure about the details of the other servers.  For example, both 
bugs.python.org and hg.python.org have CPython applications behind them: 
Roundup and Mercurial.

FTR, the whole python.org web domain is being redesigned so the details 
of what is under the covers will be changing.  Jesse Noller posted about 
the redesign process some months ago:

http://jessenoller.com/blog/2012/11/28/the-great-python-org-redesign

-- 
 Ned Deily,
 nad at acm.org



From roy at panix.com  Fri May 24 23:12:17 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 24 May 2013 23:12:17 -0400
Subject: Preventing nose from finding setup.py
Message-ID: <roy-51D3E2.23121724052013@news.panix.com>

We've got a package (with an empty __init__.py), which contains a 
setup.py file.  When I run nosetests, the test discovery code finds 
setup.py, thinks it's a test, and tries to run it (with predictably poor 
results).

Is there some way to mark this file as not a test? If it was a method in 
a file, I would decorate it with @nottest, but that doesn't work here.


From roy at panix.com  Fri May 24 23:16:57 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 24 May 2013 23:16:57 -0400
Subject: Preventing nose from finding setup.py
References: <roy-51D3E2.23121724052013@news.panix.com>
Message-ID: <roy-FAD9B3.23165724052013@news.panix.com>

In article <roy-51D3E2.23121724052013 at news.panix.com>,
 Roy Smith <roy at panix.com> wrote:

> We've got a package (with an empty __init__.py), which contains a 
> setup.py file.  When I run nosetests, the test discovery code finds 
> setup.py, thinks it's a test, and tries to run it (with predictably poor 
> results).

Ugh, I described that wrong.  Setup is also a package (with it's own 
empty __init__.py file).  But, the same problem applies.  Nosetests 
discovers it, tries to run it, and barfs with:

TypeError: Attribute setup of <module 'djsite.songza_web' from 
'/home/roy/songza/djsite/songza_web/__init__.pyc'> is not a python 
function. Only functions or callables may be used as fixtures.


From rama29065 at gmail.com  Fri May 24 23:19:06 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Fri, 24 May 2013 20:19:06 -0700 (PDT)
Subject: Python Magazine
Message-ID: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>

Planning to start a python online chronicle.What you want to see in it. :)


From dreamingforward at gmail.com  Fri May 24 23:38:28 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Fri, 24 May 2013 20:38:28 -0700
Subject: Python Magazine
In-Reply-To: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
Message-ID: <CAMjeLr8_TFS-CTP0LXxuck2cmNObvUndWiM5GESM6A8HttLqbw@mail.gmail.com>

I always liked the daily Python-URL from Dr. Dobbs.

Summaries of salient discussions on python-dev, ideas, list.

interviews with devs on philosophies.

quote of the week

--m

On 5/24/13, DRJ Reddy <rama29065 at gmail.com> wrote:
> Planning to start a python online chronicle.What you want to see in it. :)
> --
> http://mail.python.org/mailman/listinfo/python-list
>


-- 
MarkJ
Tacoma, Washington


From carlosnepomuceno at outlook.com  Fri May 24 23:43:56 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 06:43:56 +0300
Subject: Python Magazine
In-Reply-To: <CAMjeLr8_TFS-CTP0LXxuck2cmNObvUndWiM5GESM6A8HttLqbw@mail.gmail.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>,
	<CAMjeLr8_TFS-CTP0LXxuck2cmNObvUndWiM5GESM6A8HttLqbw@mail.gmail.com>
Message-ID: <BLU176-W1903CEB3352836E3B3534CD7940@phx.gbl>

In-depth articles about Python! Like security analisys of modules, packages, frameworks, everything Python related.

Performance benchmarks. How a Python technology/solution compares to other competitor technologies.

Python competitions/contests/challenges!


----------------------------------------
> Date: Fri, 24 May 2013 20:38:28 -0700
> Subject: Re: Python Magazine
> From: dreamingforward at gmail.com
> To: rama29065 at gmail.com
> CC: python-list at python.org
>
> I always liked the daily Python-URL from Dr. Dobbs.
>
> Summaries of salient discussions on python-dev, ideas, list.
>
> interviews with devs on philosophies.
>
> quote of the week
>
> --m
>
> On 5/24/13, DRJ Reddy <rama29065 at gmail.com> wrote:
>> Planning to start a python online chronicle.What you want to see in it. :)
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>>
>
>
> --
> MarkJ
> Tacoma, Washington
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rama29065 at gmail.com  Sat May 25 00:10:02 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Fri, 24 May 2013 21:10:02 -0700 (PDT)
Subject: Python Magazine
In-Reply-To: <mailman.2101.1369453439.3114.python-list@python.org>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>,>
	<CAMjeLr8_TFS-CTP0LXxuck2cmNObvUndWiM5GESM6A8HttLqbw@mail.gmail.com>
	<mailman.2101.1369453439.3114.python-list@python.org>
Message-ID: <bab8868b-b5e2-472f-8d55-ccaee5bce1ce@googlegroups.com>

On Saturday, May 25, 2013 9:13:56 AM UTC+5:30, Carlos Nepomuceno wrote:
> In-depth articles about Python! Like security analisys of modules, packages, frameworks, everything Python related.
> 
> Performance benchmarks. How a Python technology/solution compares to other competitor technologies.
> 
> Python competitions/contests/challenges!

Thankyou for your suggestions. :)


From carlosnepomuceno at outlook.com  Sat May 25 00:22:51 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 07:22:51 +0300
Subject: Python Magazine
In-Reply-To: <bab8868b-b5e2-472f-8d55-ccaee5bce1ce@googlegroups.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>, >,
	<CAMjeLr8_TFS-CTP0LXxuck2cmNObvUndWiM5GESM6A8HttLqbw@mail.gmail.com>,
	<mailman.2101.1369453439.3114.python-list@python.org>,
	<bab8868b-b5e2-472f-8d55-ccaee5bce1ce@googlegroups.com>
Message-ID: <BLU176-W228D4B9D8AB942EFBB1879D7940@phx.gbl>

----------------------------------------
> Date: Fri, 24 May 2013 21:10:02 -0700
> Subject: Re: Python Magazine
> From: rama29065 at gmail.com
> To: python-list at python.org
>
> On Saturday, May 25, 2013 9:13:56 AM UTC+5:30, Carlos Nepomuceno wrote:
>> In-depth articles about Python! Like security analisys of modules, packages, frameworks, everything Python related.
>>
>> Performance benchmarks. How a Python technology/solution compares to other competitor technologies.
>>
>> Python competitions/contests/challenges!
>
> Thankyou for your suggestions. :)
> --
> http://mail.python.org/mailman/listinfo/python-list

Also, comparison of Python flavors (CPython, PyPy, Cython, Stackles, etc.) -- How do they differ? What's the benefits and hindrances? 		 	   		  

From rosuav at gmail.com  Sat May 25 00:25:52 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 14:25:52 +1000
Subject: Python Magazine
In-Reply-To: <BLU176-W228D4B9D8AB942EFBB1879D7940@phx.gbl>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<CAMjeLr8_TFS-CTP0LXxuck2cmNObvUndWiM5GESM6A8HttLqbw@mail.gmail.com>
	<mailman.2101.1369453439.3114.python-list@python.org>
	<bab8868b-b5e2-472f-8d55-ccaee5bce1ce@googlegroups.com>
	<BLU176-W228D4B9D8AB942EFBB1879D7940@phx.gbl>
Message-ID: <CAPTjJmqhmZOEv1NFxyxXsaz9XA-L2OcPRSZ7dvmF+vLri2f9Gw@mail.gmail.com>

On Sat, May 25, 2013 at 2:22 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> Also, comparison of Python flavors (CPython, PyPy, Cython, Stackles, etc.) -- How do they differ? What's the benefits and hindrances?

Good point. Could go even more general than that: Just highlight some
lesser-known Python and show it off.

ChrisA


From roy at panix.com  Sat May 25 11:24:03 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 25 May 2013 11:24:03 -0400
Subject: Python Magazine
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<CAMjeLr8_TFS-CTP0LXxuck2cmNObvUndWiM5GESM6A8HttLqbw@mail.gmail.com>
	<mailman.2101.1369453439.3114.python-list@python.org>
	<bab8868b-b5e2-472f-8d55-ccaee5bce1ce@googlegroups.com>
	<BLU176-W228D4B9D8AB942EFBB1879D7940@phx.gbl>
	<mailman.2108.1369455962.3114.python-list@python.org>
Message-ID: <roy-D5BD61.11240325052013@news.panix.com>

In article <mailman.2108.1369455962.3114.python-list at python.org>,
 Chris Angelico <rosuav at gmail.com> wrote:

> > Also, comparison of Python flavors (CPython, PyPy, Cython, Stackles, etc.) 

Stackles?  That sounds like breakfast cereal.

"New all-natural stackles, with 12 essential vitamins, plus fiber!"


From rosuav at gmail.com  Sat May 25 11:30:56 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 01:30:56 +1000
Subject: Python Magazine
In-Reply-To: <roy-D5BD61.11240325052013@news.panix.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<CAMjeLr8_TFS-CTP0LXxuck2cmNObvUndWiM5GESM6A8HttLqbw@mail.gmail.com>
	<mailman.2101.1369453439.3114.python-list@python.org>
	<bab8868b-b5e2-472f-8d55-ccaee5bce1ce@googlegroups.com>
	<BLU176-W228D4B9D8AB942EFBB1879D7940@phx.gbl>
	<mailman.2108.1369455962.3114.python-list@python.org>
	<roy-D5BD61.11240325052013@news.panix.com>
Message-ID: <CAPTjJmrDHCYW2P5YMmATJ0VCKPszoN4RvvODiGimOSw9b2=hzQ@mail.gmail.com>

On Sun, May 26, 2013 at 1:24 AM, Roy Smith <roy at panix.com> wrote:
> In article <mailman.2108.1369455962.3114.python-list at python.org>,
>  Chris Angelico <rosuav at gmail.com> wrote:
>
>> > Also, comparison of Python flavors (CPython, PyPy, Cython, Stackles, etc.)
>
> Stackles?  That sounds like breakfast cereal.
>
> "New all-natural stackles, with 12 essential vitamins, plus fiber!"

Heh!! But watch the citations please, I didn't say that - my email was
quoting Carlos.

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 13:28:08 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 20:28:08 +0300
Subject: Python Magazine
In-Reply-To: <roy-D5BD61.11240325052013@news.panix.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>,
	<CAMjeLr8_TFS-CTP0LXxuck2cmNObvUndWiM5GESM6A8HttLqbw@mail.gmail.com>,
	<mailman.2101.1369453439.3114.python-list@python.org>,
	<bab8868b-b5e2-472f-8d55-ccaee5bce1ce@googlegroups.com>,
	<BLU176-W228D4B9D8AB942EFBB1879D7940@phx.gbl>,
	<mailman.2108.1369455962.3114.python-list@python.org>,
	<roy-D5BD61.11240325052013@news.panix.com>
Message-ID: <BLU176-W1254457475EAC19A076113D7940@phx.gbl>

----------------------------------------
> From: roy at panix.com
> Subject: Re: Python Magazine
> Date: Sat, 25 May 2013 11:24:03 -0400
> To: python-list at python.org
>
> In article <mailman.2108.1369455962.3114.python-list at python.org>,
> Chris Angelico <rosuav at gmail.com> wrote:
>
>>> Also, comparison of Python flavors (CPython, PyPy, Cython, Stackles, etc.)
>
> Stackles? That sounds like breakfast cereal.
>
> "New all-natural stackles, with 12 essential vitamins, plus fiber!"
> --
> http://mail.python.org/mailman/listinfo/python-list

lol pardon my typo! I'm really considering that cereal! lol 		 	   		  

From roy at panix.com  Fri May 24 23:35:32 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 24 May 2013 23:35:32 -0400
Subject: Python Magazine
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
Message-ID: <roy-73518B.23353224052013@news.panix.com>

In article <27969350-4dd8-4afa-881a-b4a2364b3cf1 at googlegroups.com>,
 DRJ Reddy <rama29065 at gmail.com> wrote:

> Planning to start a python online chronicle.What you want to see in it. :)

Issue 1:

"Whitespace as syntax: mistake or magic?"

"Python 3 vs. IPv6: who will win the race for early adoption?"

"Did Python 3 break unicode?  The true story"

"Tuplemania: 100 things you can do with immutable lists"


From rama29065 at gmail.com  Fri May 24 23:38:50 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Fri, 24 May 2013 20:38:50 -0700 (PDT)
Subject: Python Magazine
In-Reply-To: <roy-73518B.23353224052013@news.panix.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
Message-ID: <456f63a0-a515-493a-9565-5f3d79cd5ec2@googlegroups.com>


> Issue 1:

> "Whitespace as syntax: mistake or magic?"
Thanks Roy :)



From rosuav at gmail.com  Fri May 24 23:48:40 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 13:48:40 +1000
Subject: Python Magazine
In-Reply-To: <roy-73518B.23353224052013@news.panix.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
Message-ID: <CAPTjJmr=+dbcW0tULw=q+PBown1Jy+on+rknUpEKb8tzTwrUSQ@mail.gmail.com>

On Sat, May 25, 2013 at 1:35 PM, Roy Smith <roy at panix.com> wrote:
> "Python 3 vs. IPv6: who will win the race for early adoption?"

I think Py3 is winning that one so far. But really, both need to get
moving. Neither of my ISPs does IPv6 :(

Seconding the recommendation for QOTW, that's good fun.

ChrisA


From rama29065 at gmail.com  Sat May 25 00:11:11 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Fri, 24 May 2013 21:11:11 -0700 (PDT)
Subject: Python Magazine
In-Reply-To: <mailman.2102.1369453723.3114.python-list@python.org>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
Message-ID: <09c52944-9e80-4ae1-8490-c6451c95b17d@googlegroups.com>

This is what i love with python community faster responses. :)


From zoom at yahoo.com  Sat May 25 02:38:23 2013
From: zoom at yahoo.com (zoom)
Date: Sat, 25 May 2013 08:38:23 +0200
Subject: Python Magazine
In-Reply-To: <mailman.2102.1369453723.3114.python-list@python.org>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
Message-ID: <knpm5i$qls$1@news1.carnet.hr>

But why would anyone want to use IPv6?

On 05/25/2013 05:48 AM, Chris Angelico wrote:
> On Sat, May 25, 2013 at 1:35 PM, Roy Smith<roy at panix.com>  wrote:
>> "Python 3 vs. IPv6: who will win the race for early adoption?"
>
> I think Py3 is winning that one so far. But really, both need to get
> moving. Neither of my ISPs does IPv6 :(
>
> Seconding the recommendation for QOTW, that's good fun.
>
> ChrisA



From rosuav at gmail.com  Sat May 25 02:41:58 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 16:41:58 +1000
Subject: Python Magazine
In-Reply-To: <knpm5i$qls$1@news1.carnet.hr>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
Message-ID: <CAPTjJmqmow7ByRNU+q9JsKQHHpzq41sOujGWgFt=8XzuYm=_Zg@mail.gmail.com>

On Sat, May 25, 2013 at 4:38 PM, zoom <zoom at yahoo.com> wrote:
> But why would anyone want to use IPv6?

I hope you're not serious :)

ChrisA


From steve+comp.lang.python at pearwood.info  Sat May 25 10:29:00 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 25 May 2013 14:29:00 GMT
Subject: Python Magazine
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
Message-ID: <51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Sat, 25 May 2013 16:41:58 +1000, Chris Angelico wrote:

> On Sat, May 25, 2013 at 4:38 PM, zoom <zoom at yahoo.com> wrote:
>> But why would anyone want to use IPv6?
> 
> I hope you're not serious :)

He's planning to drop off the Internet once the IP address run out.


-- 
Steven


From roy at panix.com  Sat May 25 11:30:19 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 25 May 2013 11:30:19 -0400
Subject: Python Magazine
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-3B8F45.11301825052013@news.panix.com>

In article <51a0caac$0$30002$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> On Sat, 25 May 2013 16:41:58 +1000, Chris Angelico wrote:
> 
> > On Sat, May 25, 2013 at 4:38 PM, zoom <zoom at yahoo.com> wrote:
> >> But why would anyone want to use IPv6?
> > 
> > I hope you're not serious :)
> 
> He's planning to drop off the Internet once the IP address run out.

We already have run out.  People have gotten so used to being behind NAT 
gateways they don't even understand how evil it is.  From my phone, I 
can call any other phone anywhere in the world.  But I can't talk 
directly to the file server in my neighbor's house across the street?


From rosuav at gmail.com  Sat May 25 11:46:44 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 25 May 2013 15:46:44 -0000
Subject: Python Magazine
In-Reply-To: <roy-3B8F45.11301825052013@news.panix.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
Message-ID: <CAPTjJmrdJwThQiciJMpyf0rN=9Z+S2Taf5ZZnKbNkO6XYuobzg@mail.gmail.com>

On Sun, May 26, 2013 at 1:30 AM, Roy Smith <roy at panix.com> wrote:
> In article <51a0caac$0$30002$c3e8da3$5496439d at news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>
>> On Sat, 25 May 2013 16:41:58 +1000, Chris Angelico wrote:
>>
>> > On Sat, May 25, 2013 at 4:38 PM, zoom <zoom at yahoo.com> wrote:
>> >> But why would anyone want to use IPv6?
>> >
>> > I hope you're not serious :)
>>
>> He's planning to drop off the Internet once the IP address run out.
>
> We already have run out.  People have gotten so used to being behind NAT
> gateways they don't even understand how evil it is.  From my phone, I
> can call any other phone anywhere in the world.  But I can't talk
> directly to the file server in my neighbor's house across the street?

Of course, the shift from IPv4 and NAT to IPv6 and direct addressing
does shift the firewalling burden somewhat. Instead of "I'll forward
whatever ports I choose", it becomes "alright let's think about this
whole firewall thang". I'm not 100% confident that home-grade routers
will have proper firewall facilities in them; I suspect that moving
home users onto IPv6 may result in a spate of attacks. On the flip
side, it becomes less useful to simply port-scan across huge IP blocks
- bulk-attacking an IPv4 /24 block is easy, but spamming even a single
IPv6 /64 is practically impossible.

ChrisA


From john_ladasky at sbcglobal.net  Sat May 25 21:28:58 2013
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Sat, 25 May 2013 18:28:58 -0700 (PDT)
Subject: Python Magazine
In-Reply-To: <roy-3B8F45.11301825052013@news.panix.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
Message-ID: <7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>

On Saturday, May 25, 2013 8:30:19 AM UTC-7, Roy Smith wrote:
> From my phone, I 
> can call any other phone anywhere in the world.  But I can't talk  
> directly to the file server in my neighbor's house across the street?

Hmmm... I've been an advocate of IPv6, but... now you've got me thinking of what Iran's new cadre of hackers might do with it!  :^)


From roy at panix.com  Sat May 25 21:54:43 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 25 May 2013 21:54:43 -0400
Subject: Python Magazine
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
Message-ID: <roy-3B69E7.21544325052013@news.panix.com>

In article <7cd17be8-d455-4db8-b8d0-ccc757db5cff at googlegroups.com>,
 John Ladasky <john_ladasky at sbcglobal.net> wrote:

> On Saturday, May 25, 2013 8:30:19 AM UTC-7, Roy Smith wrote:
> > From my phone, I 
> > can call any other phone anywhere in the world.  But I can't talk  
> > directly to the file server in my neighbor's house across the street?
> 
> Hmmm... I've been an advocate of IPv6, but... now you've got me thinking of 
> what Iran's new cadre of hackers might do with it!  :^)

You (like many people) are confusing universal addressability with 
universal connectivity.  The converse of that is people confusing NAT 
with security.

Of course not every IPv6 endpoint will be able to talk to every other 
IPv6 endpoint, even if the both have globally unique addresses.  But, 
the access controls will be implemented in firewalls with appropriately 
coded security policies.  Not as an accident of being behind a NAT box.


From rosuav at gmail.com  Sat May 25 21:58:09 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 11:58:09 +1000
Subject: Python Magazine
In-Reply-To: <roy-3B69E7.21544325052013@news.panix.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
Message-ID: <CAPTjJmrEV6OdEmhE6ne_y7ExgUwr6BtN1uHeBFqTFFe7-6b29g@mail.gmail.com>

On Sun, May 26, 2013 at 11:54 AM, Roy Smith <roy at panix.com> wrote:
> In article <7cd17be8-d455-4db8-b8d0-ccc757db5cff at googlegroups.com>,
>  John Ladasky <john_ladasky at sbcglobal.net> wrote:
>
>> On Saturday, May 25, 2013 8:30:19 AM UTC-7, Roy Smith wrote:
>> > From my phone, I
>> > can call any other phone anywhere in the world.  But I can't talk
>> > directly to the file server in my neighbor's house across the street?
>>
>> Hmmm... I've been an advocate of IPv6, but... now you've got me thinking of
>> what Iran's new cadre of hackers might do with it!  :^)
>
> You (like many people) are confusing universal addressability with
> universal connectivity.  The converse of that is people confusing NAT
> with security.
>
> Of course not every IPv6 endpoint will be able to talk to every other
> IPv6 endpoint, even if the both have globally unique addresses.  But,
> the access controls will be implemented in firewalls with appropriately
> coded security policies.  Not as an accident of being behind a NAT box.

To be more specific: The control of who can talk to whom is in the
hands of the admins of the two endpoints and the nodes in between,
rather than being arbitrarily in the hands of the technology. So I
would be able to talk to the file server across the street, but only
IF its admin lets me.

ChrisA


From carlosnepomuceno at outlook.com  Sat May 25 22:14:50 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 02:14:50 -0000
Subject: Python Magazine
In-Reply-To: <CAPTjJmrEV6OdEmhE6ne_y7ExgUwr6BtN1uHeBFqTFFe7-6b29g@mail.gmail.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>,
	<roy-73518B.23353224052013@news.panix.com>,
	<mailman.2102.1369453723.3114.python-list@python.org>,
	<knpm5i$qls$1@news1.carnet.hr>,
	<mailman.2115.1369464127.3114.python-list@python.org>,
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<roy-3B8F45.11301825052013@news.panix.com>,
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>,
	<roy-3B69E7.21544325052013@news.panix.com>,
	<CAPTjJmrEV6OdEmhE6ne_y7ExgUwr6BtN1uHeBFqTFFe7-6b29g@mail.gmail.com>
Message-ID: <BLU176-W40E94D3CF0739BFFA18746D7950@phx.gbl>

I don't think IPv6 will change anything about NAPT usage. In fact, I guess, it will probably will make NAPT usage even more important and needed. 		 	   		  

From breamoreboy at yahoo.co.uk  Sat May 25 23:20:27 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 04:20:27 +0100
Subject: Python Magazine
In-Reply-To: <CAPTjJmrEV6OdEmhE6ne_y7ExgUwr6BtN1uHeBFqTFFe7-6b29g@mail.gmail.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
	<CAPTjJmrEV6OdEmhE6ne_y7ExgUwr6BtN1uHeBFqTFFe7-6b29g@mail.gmail.com>
Message-ID: <knrv0i$bvr$2@ger.gmane.org>

On 26/05/2013 02:58, Chris Angelico wrote:
> On Sun, May 26, 2013 at 11:54 AM, Roy Smith <roy at panix.com> wrote:
>> In article <7cd17be8-d455-4db8-b8d0-ccc757db5cff at googlegroups.com>,
>>   John Ladasky <john_ladasky at sbcglobal.net> wrote:
>>
>>> On Saturday, May 25, 2013 8:30:19 AM UTC-7, Roy Smith wrote:
>>>>  From my phone, I
>>>> can call any other phone anywhere in the world.  But I can't talk
>>>> directly to the file server in my neighbor's house across the street?
>>>
>>> Hmmm... I've been an advocate of IPv6, but... now you've got me thinking of
>>> what Iran's new cadre of hackers might do with it!  :^)
>>
>> You (like many people) are confusing universal addressability with
>> universal connectivity.  The converse of that is people confusing NAT
>> with security.
>>
>> Of course not every IPv6 endpoint will be able to talk to every other
>> IPv6 endpoint, even if the both have globally unique addresses.  But,
>> the access controls will be implemented in firewalls with appropriately
>> coded security policies.  Not as an accident of being behind a NAT box.
>
> To be more specific: The control of who can talk to whom is in the
> hands of the admins of the two endpoints and the nodes in between,
> rather than being arbitrarily in the hands of the technology. So I
> would be able to talk to the file server across the street, but only
> IF its admin lets me.
>
> ChrisA
>

By such means as leaving the top level admin password set to the factory 
default? :)

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From john_ladasky at sbcglobal.net  Sat May 25 23:04:28 2013
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Sat, 25 May 2013 20:04:28 -0700 (PDT)
Subject: Python Magazine
In-Reply-To: <roy-3B69E7.21544325052013@news.panix.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
Message-ID: <8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>

A perfectly fair point, Roy.  It's just when you started suggesting connecting to your neighbor's file server -- well, that's not something that many people would ordinarily do.  So, my mind leaped to the possibility of uninvited connections.

Related question: would denial-of-service attacks be more pernicious without a NAT?


From roy at panix.com  Sat May 25 23:24:39 2013
From: roy at panix.com (Roy Smith)
Date: Sat, 25 May 2013 23:24:39 -0400
Subject: Python Magazine
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
	<8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>
Message-ID: <roy-E09DD5.23243925052013@news.panix.com>

In article <8f19e20c-4f77-43dc-a732-4169e482d2b2 at googlegroups.com>,
 John Ladasky <john_ladasky at sbcglobal.net> wrote:

> A perfectly fair point, Roy.  It's just when you started suggesting 
> connecting to your neighbor's file server -- well, that's not something that 
> many people would ordinarily do.  So, my mind leaped to the possibility of 
> uninvited connections.
> 
> Related question: would denial-of-service attacks be more pernicious without 
> a NAT?

Not really.  If I know the external IP address of your NAT box, I can 
throw as much traffic at it as your internet connection will deliver.  
Assuming you have sufficient bandwidth, eventually I'll melt down your 
router.  This is equally true with NAT or without it.


From rosuav at gmail.com  Sat May 25 23:45:29 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 13:45:29 +1000
Subject: Python Magazine
In-Reply-To: <8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
	<8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>
Message-ID: <CAPTjJmqqFLjWv4Dz57EycO5DJaOYZ1E_rq7cVv2bxKkeQyXEPQ@mail.gmail.com>

On Sun, May 26, 2013 at 1:04 PM, John Ladasky
<john_ladasky at sbcglobal.net> wrote:
> A perfectly fair point, Roy.  It's just when you started suggesting connecting to your neighbor's file server -- well, that's not something that many people would ordinarily do.  So, my mind leaped to the possibility of uninvited connections.
>
> Related question: would denial-of-service attacks be more pernicious without a NAT?

Not sure what you mean. If we assume that network topology doesn't
change, then what we have is a single uplink (say, an ADSL connection,
given that most home users don't have luxuries) going to a router
(let's be generous here and say that's a Linux box with two NICs, and
you have a smart admin in charge of it), behind which is a set of
switches and computers making up a LAN of peers. On IPv4, the LAN
would operate on one of the RFC 1918 address blocks - say, 192.168.0.x
- and all external communication would be through one single IP
address - 203.0.113.47 will do for the purposes of discussion.

As far as other hosts on the internet are concerned, that entire
network is one single host, with address 203.0.113.47. It's unaware of
the three computers 192.168.0.4, .0.87, and .0.92; they merge into
one. This means they share the 65536 ports, they share entries on
blacklists, etc, etc.

With IPv6, that ADSL connection would come with a /64 block - say,
2001:db8:142:857::/64. Within that block, each computer would be
assigned a single address - perhaps 2001:db8:142:857::4,
2001:db8:142:857::87, and 2001:db8:142:857::92, or perhaps they'd be
assigned them by their MAC addresses eg
2001:db8:142:857:200:5eff:fe00:531a, which can be done automatically.
Now all your computers (including the router) are individually
addressable; they can be identified separately, or treated as a group
(the /64 representing the whole group). Their ports, blacklist
entries, etc, are all unique. This means you can run three servers on
port 80, etc.

The question now is: What sort of DOS attack are you fearing? If it's
a simple matter of saturating the connection, it makes absolutely no
difference. As Roy said, that's just a question of overloading. If I
command more bandwidth than you do, I can saturate you. Easy. (Very
easy if I have a botnet, for instance.) Harder to judge are the
amplifying attacks; a half-open-connection attack, for instance,
attacks a TCP server's RAM allocation. It's possible that some attacks
will be easier or harder with NAT than without, but you'd have to
evaluate a specific attack technique.

ChrisA


From carlosnepomuceno at outlook.com  Sun May 26 00:01:35 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 07:01:35 +0300
Subject: Python Magazine
In-Reply-To: <8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>,
	<roy-73518B.23353224052013@news.panix.com>,
	<mailman.2102.1369453723.3114.python-list@python.org>,
	<knpm5i$qls$1@news1.carnet.hr>,
	<mailman.2115.1369464127.3114.python-list@python.org>,
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<roy-3B8F45.11301825052013@news.panix.com>,
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>,
	<roy-3B69E7.21544325052013@news.panix.com>,
	<8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>
Message-ID: <BLU176-W1954E65198FBD15D34EFCBD7950@phx.gbl>

----------------------------------------
> Date: Sat, 25 May 2013 20:04:28 -0700
> Subject: Re: Python Magazine
> From: john_ladasky at sbcglobal.net
> To: python-list at python.org
>
> A perfectly fair point, Roy. It's just when you started suggesting connecting to your neighbor's file server -- well, that's not something that many people would ordinarily do. So, my mind leaped to the possibility of uninvited connections.
>
> Related question: would denial-of-service attacks be more pernicious without a NAT?
> --
> http://mail.python.org/mailman/listinfo/python-list

I don't think so.

IP blocking still a very common mitigation approach to DDoS, but it may cause denial of service to legitimate clients who share the same blocked public IP address used by the malicious clients. So, NAPT will still benefit DDoS attackers, at least temporarily (until the IP is unblocked). 		 	   		  

From rosuav at gmail.com  Sun May 26 00:31:57 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 14:31:57 +1000
Subject: Python Magazine
In-Reply-To: <BLU176-W1954E65198FBD15D34EFCBD7950@phx.gbl>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
	<8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>
	<BLU176-W1954E65198FBD15D34EFCBD7950@phx.gbl>
Message-ID: <CAPTjJmpQLO+=reaKMHLTx0YsJ5BN0iNZiyeJG6MTE1PYa_gQ6g@mail.gmail.com>

On Sun, May 26, 2013 at 2:01 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> ----------------------------------------
>> Date: Sat, 25 May 2013 20:04:28 -0700
>> Subject: Re: Python Magazine
>> From: john_ladasky at sbcglobal.net
>> To: python-list at python.org
>>
>> A perfectly fair point, Roy. It's just when you started suggesting connecting to your neighbor's file server -- well, that's not something that many people would ordinarily do. So, my mind leaped to the possibility of uninvited connections.
>>
>> Related question: would denial-of-service attacks be more pernicious without a NAT?
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
> I don't think so.
>
> IP blocking still a very common mitigation approach to DDoS, but it may cause denial of service to legitimate clients who share the same blocked public IP address used by the malicious clients. So, NAPT will still benefit DDoS attackers, at least temporarily (until the IP is unblocked).

I expect that IP blocks will be upgraded to /64 block blocks, if that
starts being a problem. But it often won't, and specific IP address
blocks will still be the norm.

ChrisA


From carlosnepomuceno at outlook.com  Sun May 26 01:00:08 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 08:00:08 +0300
Subject: Python Magazine
In-Reply-To: <CAPTjJmpQLO+=reaKMHLTx0YsJ5BN0iNZiyeJG6MTE1PYa_gQ6g@mail.gmail.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>,
	<roy-73518B.23353224052013@news.panix.com>,
	<mailman.2102.1369453723.3114.python-list@python.org>,
	<knpm5i$qls$1@news1.carnet.hr>,
	<mailman.2115.1369464127.3114.python-list@python.org>,
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<roy-3B8F45.11301825052013@news.panix.com>,
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>,
	<roy-3B69E7.21544325052013@news.panix.com>,
	<8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>,
	<BLU176-W1954E65198FBD15D34EFCBD7950@phx.gbl>,
	<CAPTjJmpQLO+=reaKMHLTx0YsJ5BN0iNZiyeJG6MTE1PYa_gQ6g@mail.gmail.com>
Message-ID: <BLU176-W14311D85344D3ED6CC31FBD7950@phx.gbl>

----------------------------------------
> Date: Sun, 26 May 2013 14:31:57 +1000
> Subject: Re: Python Magazine
> From: rosuav at gmail.com
> To: python-list at python.org
[...]
> I expect that IP blocks will be upgraded to /64 block blocks, if that
> starts being a problem. But it often won't, and specific IP address
> blocks will still be the norm.
>
> ChrisA


Blocking a whole network (/65) is totally undesirable and may even become illegal.

Currently it may not only happen at the target of the DDoS attack, but be spread all over the internet where block lists are enforced.

I don't expect that to happen and if it happens I'm surely in favor of protection against this type of 'solution' because it will block not only malicious clients but potentially many other legitimate clients. 		 	   		  

From rosuav at gmail.com  Sun May 26 01:17:11 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 15:17:11 +1000
Subject: Python Magazine
In-Reply-To: <BLU176-W14311D85344D3ED6CC31FBD7950@phx.gbl>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
	<8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>
	<BLU176-W1954E65198FBD15D34EFCBD7950@phx.gbl>
	<CAPTjJmpQLO+=reaKMHLTx0YsJ5BN0iNZiyeJG6MTE1PYa_gQ6g@mail.gmail.com>
	<BLU176-W14311D85344D3ED6CC31FBD7950@phx.gbl>
Message-ID: <CAPTjJmqMeVHq+gcX44=9=FFGuCszAD4rndDZnXEwXddW8+i3OQ@mail.gmail.com>

On Sun, May 26, 2013 at 3:00 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> ----------------------------------------
>> Date: Sun, 26 May 2013 14:31:57 +1000
>> Subject: Re: Python Magazine
>> From: rosuav at gmail.com
>> To: python-list at python.org
> [...]
>> I expect that IP blocks will be upgraded to /64 block blocks, if that
>> starts being a problem. But it often won't, and specific IP address
>> blocks will still be the norm.
>>
>> ChrisA
>
>
> Blocking a whole network (/65) is totally undesirable and may even become illegal.

Blocking a /64 is exactly the same as blocking a /32 with NAT behind
it. And how could it be illegal? I provide service to those I choose
to provide to.

> Currently it may not only happen at the target of the DDoS attack, but be spread all over the internet where block lists are enforced.
>
> I don't expect that to happen and if it happens I'm surely in favor of protection against this type of 'solution' because it will block not only malicious clients but potentially many other legitimate clients.

Banning a wide netblock is of course going to lock out legit clients.
But IP rotation means that can happen anyway. You block a single IPv4
address that right now represents an abusive user; that user
disconnects and reconnects, gets a new IP, and someone else gets the
other one. Can happen all too easily. That's why IP-banning is at best
a temporary solution anyway.

ChrisA


From carlosnepomuceno at outlook.com  Sun May 26 01:44:10 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 05:44:10 -0000
Subject: Python Magazine
In-Reply-To: <CAPTjJmqMeVHq+gcX44=9=FFGuCszAD4rndDZnXEwXddW8+i3OQ@mail.gmail.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>,
	<roy-73518B.23353224052013@news.panix.com>,
	<mailman.2102.1369453723.3114.python-list@python.org>,
	<knpm5i$qls$1@news1.carnet.hr>,
	<mailman.2115.1369464127.3114.python-list@python.org>,
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<roy-3B8F45.11301825052013@news.panix.com>,
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>,
	<roy-3B69E7.21544325052013@news.panix.com>,
	<8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>,
	<BLU176-W1954E65198FBD15D34EFCBD7950@phx.gbl>,
	<CAPTjJmpQLO+=reaKMHLTx0YsJ5BN0iNZiyeJG6MTE1PYa_gQ6g@mail.gmail.com>,
	<BLU176-W14311D85344D3ED6CC31FBD7950@phx.gbl>,
	<CAPTjJmqMeVHq+gcX44=9=FFGuCszAD4rndDZnXEwXddW8+i3OQ@mail.gmail.com>
Message-ID: <BLU176-W11B37D1D31D8A66EC593B1D7950@phx.gbl>

----------------------------------------
> Date: Sun, 26 May 2013 15:17:11 +1000
> Subject: Re: Python Magazine
> From: rosuav at gmail.com
[...]
>> Blocking a whole network (/65) is totally undesirable and may even become illegal.
>
> Blocking a /64 is exactly the same as blocking a /32 with NAT behind
> it. And how could it be illegal? I provide service to those I choose
> to provide to.

I'm not a lawyer, so what I say about the IP blocking legal matter is just an opinion. I'm not responsible for any damages it may cause to anyone!!! lol

It just looks like those damn software disclaimers, doesn't it? ;)

Depending on the jurisdiction things maybe very different.

I've been told that in California it is really illegal to block IP addresses without a court order. Any Californians available to confirm that?

"The sender of information over the Internet is the "owner" of both the information and the IP address attached to the information. The practice of IP address blocking "records" the IP address and "destroys" the information in the message "without the intent or permission of the owner of the information," and "usurp[s] the normal operation of the . . computer network." Software designed to record IP addresses and use them to block messages is thus a "computer contaminant" according to the above definition. "

Source: http://im-from-missouri.blogspot.com.br/2007/05/ip-address-blocking-is-illegal-in.html


Also check California Penal Code Section 502, "Unauthorized Access To Computers, Computer Systems and Computer Data":
http://www.leginfo.ca.gov/cgi-bin/displaycode?section=pen&group=00001-01000&file=484-502.9


The problem is serious and there are many cases, such as:
http://www.theregister.co.uk/2011/10/13/dutch_isp_accuses_spamhaus/


>> Currently it may not only happen at the target of the DDoS attack, but be spread all over the internet where block lists are enforced.
>>
>> I don't expect that to happen and if it happens I'm surely in favor of protection against this type of 'solution' because it will block not only malicious clients but potentially many other legitimate clients.
>
> Banning a wide netblock is of course going to lock out legit clients.
> But IP rotation means that can happen anyway. You block a single IPv4
> address that right now represents an abusive user; that user
> disconnects and reconnects, gets a new IP, and someone else gets the
> other one. Can happen all too easily. That's why IP-banning is at best
> a temporary solution anyway.

IP blocking isn't a perfect solution as you have confirmed. That's why using it is so problematic. It may hurt legitimate clients and other unrelated ones, while the "abusive user" as you said gets out unharmed. 		 	   		  

From rama29065 at gmail.com  Fri May 31 07:11:06 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Fri, 31 May 2013 04:11:06 -0700 (PDT)
Subject: Python Magazine
In-Reply-To: <mailman.2167.1369545433.3114.python-list@python.org>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
	<8f19e20c-4f77-43dc-a732-4169e482d2b2@googlegroups.com>
	<BLU176-W1954E65198FBD15D34EFCBD7950@phx.gbl>
	<CAPTjJmpQLO+=reaKMHLTx0YsJ5BN0iNZiyeJG6MTE1PYa_gQ6g@mail.gmail.com>
	<BLU176-W14311D85344D3ED6CC31FBD7950@phx.gbl>
	<mailman.2167.1369545433.3114.python-list@python.org>
Message-ID: <29be50bf-b77c-4450-9d7c-026bfaf7fe89@googlegroups.com>

Hello all,
    Was busy with work. Finally finished the job of registering the domain name.
Will be live soon. The url is http://pythonmagazine.org. Hope we will be live soon.
Regards,
DRJ.


From steve+comp.lang.python at pearwood.info  Sat May 25 23:50:31 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 26 May 2013 03:50:31 GMT
Subject: Python Magazine
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
Message-ID: <51a18686$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Sat, 25 May 2013 21:54:43 -0400, Roy Smith wrote:

> Of course not every IPv6 endpoint will be able to talk to every other
> IPv6 endpoint, even if the both have globally unique addresses.  But,
> the access controls will be implemented in firewalls with appropriately
> coded security policies.

Or, more likely, *not* implemented in firewalls with *inappropriately* 
coded security policies.



-- 
Steven


From steve+comp.lang.python at pearwood.info  Sun May 26 00:03:18 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 26 May 2013 04:03:18 GMT
Subject: Python Magazine
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
	<mailman.2155.1369533497.3114.python-list@python.org>
Message-ID: <51a18986$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Sun, 26 May 2013 11:58:09 +1000, Chris Angelico wrote:

> On Sun, May 26, 2013 at 11:54 AM, Roy Smith <roy at panix.com> wrote:

>> Of course not every IPv6 endpoint will be able to talk to every other
>> IPv6 endpoint, even if the both have globally unique addresses.  But,
>> the access controls will be implemented in firewalls with appropriately
>> coded security policies.  Not as an accident of being behind a NAT box.
> 
> To be more specific: The control of who can talk to whom is in the hands
> of the admins of the two endpoints and the nodes in between, rather than
> being arbitrarily in the hands of the technology. So I would be able to
> talk to the file server across the street, but only IF its admin lets
> me.

Or when (not if) you find a vulnerability in the particular firewall. 
Make no mistake: the most secure entry point is the one that isn't there.



-- 
Steven


From rosuav at gmail.com  Sun May 26 00:37:21 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 14:37:21 +1000
Subject: Python Magazine
In-Reply-To: <51a18986$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<roy-73518B.23353224052013@news.panix.com>
	<mailman.2102.1369453723.3114.python-list@python.org>
	<knpm5i$qls$1@news1.carnet.hr>
	<mailman.2115.1369464127.3114.python-list@python.org>
	<51a0caac$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<roy-3B8F45.11301825052013@news.panix.com>
	<7cd17be8-d455-4db8-b8d0-ccc757db5cff@googlegroups.com>
	<roy-3B69E7.21544325052013@news.panix.com>
	<mailman.2155.1369533497.3114.python-list@python.org>
	<51a18986$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmqihObqw+r-_MzmOOjU0g07HhG9O5j--W6=CtckNOZ5Qg@mail.gmail.com>

On Sun, May 26, 2013 at 2:03 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Sun, 26 May 2013 11:58:09 +1000, Chris Angelico wrote:
>
>> On Sun, May 26, 2013 at 11:54 AM, Roy Smith <roy at panix.com> wrote:
>
>>> Of course not every IPv6 endpoint will be able to talk to every other
>>> IPv6 endpoint, even if the both have globally unique addresses.  But,
>>> the access controls will be implemented in firewalls with appropriately
>>> coded security policies.  Not as an accident of being behind a NAT box.
>>
>> To be more specific: The control of who can talk to whom is in the hands
>> of the admins of the two endpoints and the nodes in between, rather than
>> being arbitrarily in the hands of the technology. So I would be able to
>> talk to the file server across the street, but only IF its admin lets
>> me.
>
> Or when (not if) you find a vulnerability in the particular firewall.
> Make no mistake: the most secure entry point is the one that isn't there.

Packets have to get somewhere. If they come into this computer, it has
to deliberately forward them to that computer or they won't get there.
Same thing. All it takes is

# ip6tables -p FORWARD DROP

and you have a "secure unless I specifically permit it" router.
Obviously an attacker can target the router itself (which is exactly
the same as current situation), but can't attack anything beyond it
without an explicit forwarding rule (which is also exactly the same).

ChrisA


From rama29065 at gmail.com  Fri May 24 23:41:55 2013
From: rama29065 at gmail.com (DRJ Reddy)
Date: Fri, 24 May 2013 20:41:55 -0700 (PDT)
Subject: Python Magazine
In-Reply-To: <mailman.2100.1369453117.3114.python-list@python.org>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<mailman.2100.1369453117.3114.python-list@python.org>
Message-ID: <1db38d4f-55a3-41c5-9f72-194458f90f9f@googlegroups.com>

On Saturday, May 25, 2013 9:08:28 AM UTC+5:30, zipher wrote:
> I always liked the daily Python-URL from Dr. Dobbs.
 
> quote of the week

Thanks zipher we have already planned to continue Python-URL and quote of the week.
We will plan for other things that you have mentioned.
Thanks again :)



From michael.poeltl at univie.ac.at  Sat May 25 01:29:37 2013
From: michael.poeltl at univie.ac.at (Michael Poeltl)
Date: Sat, 25 May 2013 07:29:37 +0200
Subject: Python Magazine
In-Reply-To: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
Message-ID: <20130525052937.GE1537@horus.cms.at>

* DRJ Reddy <rama29065 at gmail.com> [2013-05-25 05:26]:
> Planning to start a python online chronicle.What you want to see in it. :)
- idiomatic python (common mistakes; do it 'pythonically')
- interviews
- challenge of the week (how would you solve that?)
- python for kids
- scientific python news
- new python-books

- 


> -- 
> http://mail.python.org/mailman/listinfo/python-list

-- 
  Michael Poeltl <michael.poeltl at univie.ac.at>
  Computational Materials Physics at University
  Wien, Sensengasse 8/12, A-1090 Wien, AUSTRIA
  http://cmp.univie.ac.at/
  http://homepage.univie.ac.at/michael.poeltl/
  using elinks-0.12, mutt-1.5.21, and vim-7.3,
  with python-3.2.3, on slackware-13.37   :-)
  fon: +43-1-4277-51409


From danielrr2 at gmail.com  Sat May 25 10:56:21 2013
From: danielrr2 at gmail.com (Daniel)
Date: Sat, 25 May 2013 16:56:21 +0200
Subject: Python Magazine
In-Reply-To: <20130525052937.GE1537@horus.cms.at>
References: <27969350-4dd8-4afa-881a-b4a2364b3cf1@googlegroups.com>
	<20130525052937.GE1537@horus.cms.at>
Message-ID: <217502BF-6086-4102-98A6-51C9030D4F8D@gmail.com>

All of the above, plus:

- Best Pythonic tools for GUI

- notorious projects (in science, education, NGOs, etc) using python

Please keep us informed, and best wishes

Daniel

El 25/05/2013, a las 07:29, Michael Poeltl <michael.poeltl at univie.ac.at> escribi?:

> * DRJ Reddy <rama29065 at gmail.com> [2013-05-25 05:26]:
>> Planning to start a python online chronicle.What you want to see in it. :)
> - idiomatic python (common mistakes; do it 'pythonically')
> - interviews
> - challenge of the week (how would you solve that?)
> - python for kids
> - scientific python news
> - new python-books
> 
> - 
> 
> 
>> -- 
>> http://mail.python.org/mailman/listinfo/python-list
> 
> -- 
>  Michael Poeltl <michael.poeltl at univie.ac.at>
>  Computational Materials Physics at University
>  Wien, Sensengasse 8/12, A-1090 Wien, AUSTRIA
>  http://cmp.univie.ac.at/
>  http://homepage.univie.ac.at/michael.poeltl/
>  using elinks-0.12, mutt-1.5.21, and vim-7.3,
>  with python-3.2.3, on slackware-13.37   :-)
>  fon: +43-1-4277-51409
> -- 
> http://mail.python.org/mailman/listinfo/python-list


From carlosnepomuceno at outlook.com  Fri May 24 23:59:52 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 06:59:52 +0300
Subject: Source code as text/plain
Message-ID: <BLU176-W34BC973BB636120A850895D7940@phx.gbl>

I'd like to have the option to download the source code as text/plain from the docs.python.org pages.

For example: when I'm a docs page, such as:

http://docs.python.org/2/library/string.html

and I click the source code link I'm taken to a Mercurial page:

http://hg.python.org/cpython/file/2.7/Lib/string.py

but over there there's no way to get a clean text/plain version of the code because the line numbers are included.

A link to the text/plain version on that page would be nice! 		 	   		  

From clp2 at rebertia.com  Sat May 25 00:06:05 2013
From: clp2 at rebertia.com (Chris Rebert)
Date: Fri, 24 May 2013 21:06:05 -0700
Subject: Source code as text/plain
In-Reply-To: <BLU176-W34BC973BB636120A850895D7940@phx.gbl>
References: <BLU176-W34BC973BB636120A850895D7940@phx.gbl>
Message-ID: <CAMZYqRQjsoKxU25Wt3gWefumTh=_sFogf38B9z4vGXrQXcFCgQ@mail.gmail.com>

On May 24, 2013 9:02 PM, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
wrote:
>
> I'd like to have the option to download the source code as text/plain
from the docs.python.org pages.
>
> For example: when I'm a docs page, such as:
>
> http://docs.python.org/2/library/string.html
>
> and I click the source code link I'm taken to a Mercurial page:
>
> http://hg.python.org/cpython/file/2.7/Lib/string.py
>
> but over there there's no way to get a clean text/plain version of the
code because the line numbers are included.
>
> A link to the text/plain version on that page would be nice!

It's already there. Click the "raw" link in the sidebar. In this case, at
this moment, it sends you to
http://hg.python.org/cpython/raw-file/f4981d8eb401/Lib/string.py
-------------- next part --------------
An HTML attachment was scrubbed...
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From carlosnepomuceno at outlook.com  Sat May 25 00:12:05 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 07:12:05 +0300
Subject: Source code as text/plain
In-Reply-To: <CAMZYqRQjsoKxU25Wt3gWefumTh=_sFogf38B9z4vGXrQXcFCgQ@mail.gmail.com>
References: <BLU176-W34BC973BB636120A850895D7940@phx.gbl>,
	<CAMZYqRQjsoKxU25Wt3gWefumTh=_sFogf38B9z4vGXrQXcFCgQ@mail.gmail.com>
Message-ID: <BLU176-W13D5A9D2D46DA08969398DD7940@phx.gbl>

Oh great! Thank you!

________________________________
> Date: Fri, 24 May 2013 21:06:05 -0700 
> Subject: Re: Source code as text/plain 
> From: clp2 at rebertia.com 
> To: carlosnepomuceno at outlook.com 
> CC: python-list at python.org 
>  
>  
> On May 24, 2013 9:02 PM, "Carlos Nepomuceno"  
> <carlosnepomuceno at outlook.com<mailto:carlosnepomuceno at outlook.com>>  
> wrote: 
> > 
> > I'd like to have the option to download the source code as text/plain  
> from the docs.python.org<http://docs.python.org> pages. 
> > 
> > For example: when I'm a docs page, such as: 
> > 
> > http://docs.python.org/2/library/string.html 
> > 
> > and I click the source code link I'm taken to a Mercurial page: 
> > 
> > http://hg.python.org/cpython/file/2.7/Lib/string.py 
> > 
> > but over there there's no way to get a clean text/plain version of  
> the code because the line numbers are included. 
> > 
> > A link to the text/plain version on that page would be nice! 
>  
> It's already there. Click the "raw" link in the sidebar. In this case,  
> at this moment, it sends you to 
> http://hg.python.org/cpython/raw-file/f4981d8eb401/Lib/string.py 		 	   		  

From as at sci.fi  Tue May 28 09:31:33 2013
From: as at sci.fi (Anssi Saari)
Date: Tue, 28 May 2013 16:31:33 +0300
Subject: Source code as text/plain
References: <mailman.2104.1369454400.3114.python-list@python.org>
Message-ID: <vg338t7i62y.fsf@coffee.modeemi.fi>

Carlos Nepomuceno <carlosnepomuceno at outlook.com> writes:

> I'd like to have the option to download the source code as text/plain from the docs.python.org pages.
>
> For example: when I'm a docs page, such as:
>
> http://docs.python.org/2/library/string.html
>
> and I click the source code link I'm taken to a Mercurial page:

> http://hg.python.org/cpython/file/2.7/Lib/string.py
>
> but over there there's no way to get a clean text/plain version of the code because the line numbers are included.
>
> A link to the text/plain version on that page would be nice! 		 	   		  

The 'raw' link on the left spews the source as application/binary so
most likely your browser will download it instead of showing it. Which
is what you asked but if you wanted to view in browser sans the line
numbers, there doesn't seem to be a way.


From renegrothmann at gmail.com  Sat May 25 05:52:08 2013
From: renegrothmann at gmail.com (Rene Grothmann)
Date: Sat, 25 May 2013 02:52:08 -0700 (PDT)
Subject: Py_Initialize and Py_Finalize and MatPlotlib
Message-ID: <5c9913be-5a59-4a78-a85d-ac87e7c0dd15@googlegroups.com>

This is a known problem, but I want to ask the experts for the best way to solve it for me.

I have a project (Euler Math Toolbox), which runs Python as a script language. For this, a library module "python.dll" is loaded at run time, which is linked against "python27.lib". Then Py_Initialize is called. This all works well.

But Euler can be restarted by the user with a new session and notebook. Then I want Python to clear all variables and imports. For this, I call Py_Finalize and unload "python.dll". When Python is needed, loading and initializing starts Python again.

This works. But Python crashes at the first call, if MatPlotlib is imported in the previous session. It seems that Py_Finalize does not completely clear Python, nor does unloading my "python.dll". I tried unloading "python27.dll" (the Python DLL), but this does not help. Most likey, another DLL remains active, but corrupts during Py_Finalize.

To solve this, it would suffice to clear all variables and imports. I could live with not calling Py_Finalize. But how?

PS: You may wonder, why I do not directly link euler.exe to Python. The reason is that this prevents Euler form starting, if Python is not installed, even if it is never needed.

Thanks for any answers! You duplicate your answer to renegrothmann at gmail, if you like. That would help me.


From rnyk1991 at gmail.com  Sat May 25 06:52:24 2013
From: rnyk1991 at gmail.com (Rakshith Nayak)
Date: Sat, 25 May 2013 03:52:24 -0700 (PDT)
Subject: Text-to-Sound or Vice Versa (Method NOT the source code)
Message-ID: <02102fc9-9826-4f0f-be77-8809ea179226@googlegroups.com>

Always wondered how sound is generated from text. Googling couldn't help. Devs having knowledge about this could provide, the information, Links, URLs or anything that could help. 

<Helpful for those who want to dig to basics first before Coding>


From gd.usenet at spamfence.net  Sat May 25 08:30:18 2013
From: gd.usenet at spamfence.net (=?ISO-8859-1?Q?G=FCnther?= Dietrich)
Date: Sat, 25 May 2013 14:30:18 +0200
Subject: Text-to-Sound or Vice Versa (Method NOT the source code)
References: <02102fc9-9826-4f0f-be77-8809ea179226@googlegroups.com>
Message-ID: <gd.usenet-869230.14301825052013@dwarf.main.lan>

Rakshith Nayak <rnyk1991 at gmail.com> wrote:

>Always wondered how sound is generated from text. Googling couldn't help. Devs 
>having knowledge about this could provide, the information, Links, URLs or 
>anything that could help. 

Perhaps try 'text to speech' instead of 'text to sound'?



Best regards,

G?nther


From rustompmody at gmail.com  Sat May 25 12:29:18 2013
From: rustompmody at gmail.com (rusi)
Date: Sat, 25 May 2013 09:29:18 -0700 (PDT)
Subject: Text-to-Sound or Vice Versa (Method NOT the source code)
References: <02102fc9-9826-4f0f-be77-8809ea179226@googlegroups.com>
Message-ID: <45040d72-c611-43c9-b23e-8d536ff72800@wg15g2000pbb.googlegroups.com>

On May 25, 3:52?pm, Rakshith Nayak <rnyk1... at gmail.com> wrote:
> Always wondered how sound is generated from text. Googling couldn't help. Devs having knowledge about this could provide, the information, Links, URLs or anything that could help.
>
> <Helpful for those who want to dig to basics first before Coding>

look for speech synthesis

http://en.wikipedia.org/wiki/Speech_synthesis


From invalid at invalid.invalid  Tue May 28 11:10:03 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 15:10:03 +0000 (UTC)
Subject: Text-to-Sound or Vice Versa (Method NOT the source code)
References: <02102fc9-9826-4f0f-be77-8809ea179226@googlegroups.com>
Message-ID: <ko2hcb$i4q$1@reader1.panix.com>

On 2013-05-25, Rakshith Nayak <rnyk1991 at gmail.com> wrote:

> Always wondered how sound is generated from text. Googling couldn't
> help. Devs having knowledge about this could provide, the
> information, Links, URLs or anything that could help. 
>
><Helpful for those who want to dig to basics first before Coding>

http://www.cstr.ed.ac.uk/projects/festival/
http://code.google.com/p/pyfestival/
http://machakux.appspot.com/blog/44003/making_speech_with_python

-- 
Grant Edwards               grant.b.edwards        Yow!
                                  at               BI-BI-BI-BI-BI-BI
                              gmail.com            


From rustompmody at gmail.com  Wed May 29 06:08:54 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 29 May 2013 03:08:54 -0700 (PDT)
Subject: Text-to-Sound or Vice Versa (Method NOT the source code)
References: <02102fc9-9826-4f0f-be77-8809ea179226@googlegroups.com>
	<ko2hcb$i4q$1@reader1.panix.com>
	<mailman.2333.1369783862.3114.python-list@python.org>
Message-ID: <3460cbe9-8270-4634-9b47-18a7dc580588@li6g2000pbb.googlegroups.com>

On May 29, 4:30?am, Dennis Lee Bieber <wlfr... at ix.netcom.com> wrote:
> On Tue, 28 May 2013 15:10:03 +0000 (UTC), Grant Edwards
> <inva... at invalid.invalid> declaimed the following in
> gmane.comp.python.general:
>
> > On 2013-05-25, Rakshith Nayak <rnyk1... at gmail.com> wrote:
>
> > > Always wondered how sound is generated from text. Googling couldn't
> > > help. Devs having knowledge about this could provide, the
> > > information, Links, URLs or anything that could help.
>
> > ><Helpful for those who want to dig to basics first before Coding>
>
> >http://www.cstr.ed.ac.uk/projects/festival/
> >http://code.google.com/p/pyfestival/
> >http://machakux.appspot.com/blog/44003/making_speech_with_python
>
> ? ? ? ? I suppose one could go for archaic and complex...
>
> ? ? ? ? Obtain a working Amiga computer, install whatever the last Python
> version was available pre-built. Then write a server application which
> would take text over the net, and feed it to the appropriate Amiga
> libraries -- translator and narrator as I recall (one converted plain
> text to phoneme codings, the other then converted phonemes to sound, and
> could return values for "mouth shape" to sync animation) [history: the
> Amiga had text to speech in the late 80s -- it even allowed for
> adjusting some formant parameters so one could create pseudo accents].

If venerable history is wanted, there is (always?!) emacs:
http://emacspeak.sourceforge.net/
This seems to go back to version 19 of emacs which is (c) mid-
nineties


From pythonasad at gmail.com  Sat May 25 08:41:11 2013
From: pythonasad at gmail.com (Asad Hasan)
Date: Sat, 25 May 2013 18:11:11 +0530
Subject: Learning Python
Message-ID: <CAJS9rc5hPtNB8ZeZQrbD_D6ErByGOWvy2BkA_P+osPMfK7naLA@mail.gmail.com>

Hi All ,

         I have started leaning Python through web . Would like to know if
I should follow any book so that basics become clear with examples also
want to know like in perl i use to invoke perl -d to get a debugged output
is there any option in python.

THanks,
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From steve+comp.lang.python at pearwood.info  Sat May 25 10:35:47 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 25 May 2013 14:35:47 GMT
Subject: Learning Python
References: <mailman.2131.1369486567.3114.python-list@python.org>
Message-ID: <51a0cc42$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Sat, 25 May 2013 18:11:11 +0530, Asad Hasan wrote:

> I have started leaning Python through web . Would like to know
> if I should follow any book so that basics become clear with examples 

Reading books is a good thing to do.


> also
> want to know like in perl i use to invoke perl -d to get a debugged
> output is there any option in python.

Yes. Instead of calling your script like this:

    python myscript.py

call it like this:

    python -m pdb myscript.py



-- 
Steven


From carlosnepomuceno at outlook.com  Sat May 25 13:26:53 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sat, 25 May 2013 20:26:53 +0300
Subject: Learning Python
In-Reply-To: <CAJS9rc5hPtNB8ZeZQrbD_D6ErByGOWvy2BkA_P+osPMfK7naLA@mail.gmail.com>
References: <CAJS9rc5hPtNB8ZeZQrbD_D6ErByGOWvy2BkA_P+osPMfK7naLA@mail.gmail.com>
Message-ID: <BLU176-W12792DABFBA7F838363E9AD7940@phx.gbl>

________________________________
> Date: Sat, 25 May 2013 18:11:11 +0530 
> Subject: Learning Python 
> From: pythonasad at gmail.com 
> To: Python-list at python.org 
>  
> Hi All , 
>  
>           I have started leaning Python through web . Would like to know  
> if I should follow any book so that basics become clear with examples  
> also want to know like in perl i use to invoke perl -d to get a  
> debugged output is there any option in python. 
>  
> THanks, 
>  
> -- http://mail.python.org/mailman/listinfo/python-list


I have used those:

"Dive into Python" (2004)[1]
"Python Programming" (2012)[2]
"Programming Python, 3rd Ed" (2006) [print]
? 
[1] http://www.diveintopython.net/
[1] http://en.wikibooks.org/wiki/Python_Programming 		 	   		  

From darin.hensley at gmail.com  Sat May 25 23:09:08 2013
From: darin.hensley at gmail.com (darin.hensley at gmail.com)
Date: Sat, 25 May 2013 20:09:08 -0700 (PDT)
Subject: Automate Grabbing Email From Outlook On Shared Folder
Message-ID: <d031b8c2-0936-4cdf-af53-eb46847351a3@googlegroups.com>

I am trying to automate Outlook mail client by retrieving a message with an attachment, using win32com. The message box is a shared folder that is not really underneath root folder inbox, so I had no success with inbox = mapi.GetDefaultFolder(6). However, I did have some success with:

    import win32com.client
    outlook = win32com.client.Dispatch("Outlook.Application")
    mapi = outlook.GetNamespace("MAPI").Folders
    print mapi[7]

In which the output is "Mailbox - Foo Operations"--- the folder I want.

However, if I tried:
import win32com.client
outlook = win32com.client.Dispatch("Outlook.Application")
mapi = outlook.GetNamespace("MAPI").Folders
messages = mapi[7].Items
message = messages.getLast()
body_content = message.body
print body_content

I get no success. So I am pretty much stuck. I googled many things but no success. I prefer to win32com since I don't have to use a login in the script. But if this is possible with another Python module with no login requirement that would be great also.



From cdorm245 at gmail.com  Sat May 25 23:55:42 2013
From: cdorm245 at gmail.com (cdorm245 at gmail.com)
Date: Sat, 25 May 2013 20:55:42 -0700 (PDT)
Subject: CrazyHTTPd - HTTP Daemon in Python
Message-ID: <ba07afc2-41c7-4c42-b4e7-75f39bf7bda0@googlegroups.com>

This is a small little Project that I have started. Its a light little Web Server (HTTPd) coded in python. Requirements: Python 2.7 =< And Linux / BSD. I believe this could work in a CLI Emulator in windows too.
Welcome to check out the website powered by CrazyHTTPd: http://web.crazycoder.me:14081/index.html

Please Email me with any bugs, errors, and/or comments about my little project: cdorm245 at gmail.com


From breamoreboy at yahoo.co.uk  Sun May 26 00:06:50 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 05:06:50 +0100
Subject: CrazyHTTPd - HTTP Daemon in Python
In-Reply-To: <ba07afc2-41c7-4c42-b4e7-75f39bf7bda0@googlegroups.com>
References: <ba07afc2-41c7-4c42-b4e7-75f39bf7bda0@googlegroups.com>
Message-ID: <kns1ne$2kr$1@ger.gmane.org>

On 26/05/2013 04:55, cdorm245 at gmail.com wrote:
> This is a small little Project that I have started. Its a light little Web Server (HTTPd) coded in python. Requirements: Python 2.7 =< And Linux / BSD. I believe this could work in a CLI Emulator in windows too.
> Welcome to check out the website powered by CrazyHTTPd: http://web.crazycoder.me:14081/index.html
>
> Please Email me with any bugs, errors, and/or comments about my little project: cdorm245 at gmail.com
>

IMHO writing a project right now that is limited to Python 2 is about as 
much use as a chocolate teapot.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From carlosnepomuceno at outlook.com  Sun May 26 00:21:46 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 07:21:46 +0300
Subject: CrazyHTTPd - HTTP Daemon in Python
In-Reply-To: <kns1ne$2kr$1@ger.gmane.org>
References: <ba07afc2-41c7-4c42-b4e7-75f39bf7bda0@googlegroups.com>,
	<kns1ne$2kr$1@ger.gmane.org>
Message-ID: <BLU176-W314461E41BF583C9DB527D7950@phx.gbl>

Your code isn't threaded. I suggest you consider[1] and take that road! ;) Good luck!

[1] http://bulk.fefe.de/scalable-networking.pdf

----------------------------------------
> To: python-list at python.org
> From: breamoreboy at yahoo.co.uk
> Subject: Re: CrazyHTTPd - HTTP Daemon in Python
> Date: Sun, 26 May 2013 05:06:50 +0100
>
> On 26/05/2013 04:55, cdorm245 at gmail.com wrote:
>> This is a small little Project that I have started. Its a light little Web Server (HTTPd) coded in python. Requirements: Python 2.7 =< And Linux / BSD. I believe this could work in a CLI Emulator in windows too.
>> Welcome to check out the website powered by CrazyHTTPd: http://web.crazycoder.me:14081/index.html
>>
>> Please Email me with any bugs, errors, and/or comments about my little project: cdorm245 at gmail.com
>>
>
> IMHO writing a project right now that is limited to Python 2 is about as
> much use as a chocolate teapot.
>
> --
> If you're using GoogleCrap? please read this
> http://wiki.python.org/moin/GoogleGroupsPython.
>
> Mark Lawrence
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From cdorm245 at gmail.com  Sun May 26 00:58:13 2013
From: cdorm245 at gmail.com (cdorm245 at gmail.com)
Date: Sat, 25 May 2013 21:58:13 -0700 (PDT)
Subject: CrazyHTTPd - HTTP Daemon in Python
In-Reply-To: <mailman.2161.1369542110.3114.python-list@python.org>
References: <ba07afc2-41c7-4c42-b4e7-75f39bf7bda0@googlegroups.com>,>
	<kns1ne$2kr$1@ger.gmane.org>
	<mailman.2161.1369542110.3114.python-list@python.org>
Message-ID: <16df12e2-f8c4-4551-bbb0-702056274914@googlegroups.com>

On Sunday, May 26, 2013 12:21:46 PM UTC+8, Carlos Nepomuceno wrote:
> Your code isn't threaded. I suggest you consider[1] and take that road! ;) Good luck!
> 
> [1] http://bulk.fefe.de/scalable-networking.pdf
> 
> ----------------------------------------
> > To: python-list at python.org
> > From: breamoreboy at yahoo.co.uk
> > Subject: Re: CrazyHTTPd - HTTP Daemon in Python
> > Date: Sun, 26 May 2013 05:06:50 +0100
> >
> > On 26/05/2013 04:55, cdorm245 at gmail.com wrote:
> >> This is a small little Project that I have started. Its a light little Web Server (HTTPd) coded in python. Requirements: Python 2.7 =< And Linux / BSD. I believe this could work in a CLI Emulator in windows too.
> >> Welcome to check out the website powered by CrazyHTTPd: http://web.crazycoder.me:14081/index.html
> >>
> >> Please Email me with any bugs, errors, and/or comments about my little project: cdorm245 at gmail.com
> >>
> >
> > IMHO writing a project right now that is limited to Python 2 is about as
> > much use as a chocolate teapot.
> >
> > --
> > If you're using GoogleCrap? please read this
> > http://wiki.python.org/moin/GoogleGroupsPython.
> >
> > Mark Lawrence
> >
> > --
> > http://mail.python.org/mailman/listinfo/python-list

Thanks, I plan on doing this. Then CrazyHTTPd will support bigger file downloading and multiple network connections at once. Thanks Again!


From fabiosantosart at gmail.com  Sun May 26 05:21:19 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Sun, 26 May 2013 10:21:19 +0100
Subject: CrazyHTTPd - HTTP Daemon in Python
In-Reply-To: <kns1ne$2kr$1@ger.gmane.org>
References: <ba07afc2-41c7-4c42-b4e7-75f39bf7bda0@googlegroups.com>
	<kns1ne$2kr$1@ger.gmane.org>
Message-ID: <CAA=1kxQq8P4k-CuzBmTrcEiASyeAkcaJxJvvry55wURcVjEqqA@mail.gmail.com>

On 26 May 2013 05:18, "Mark Lawrence" <breamoreboy at yahoo.co.uk> wrote:
>
> On 26/05/2013 04:55, cdorm245 at gmail.com wrote:
>>
>> This is a small little Project that I have started. Its a light little
Web Server (HTTPd) coded in python. Requirements: Python 2.7 =< And Linux /
BSD. I believe this could work in a CLI Emulator in windows too.
>> Welcome to check out the website powered by CrazyHTTPd:
http://web.crazycoder.me:14081/index.html
>>
>> Please Email me with any bugs, errors, and/or comments about my little
project: cdorm245 at gmail.com
>>
>
> IMHO writing a project right now that is limited to Python 2 is about as
much use as a chocolate teapot.
>
> --
> If you're using GoogleCrap? please read this
http://wiki.python.org/moin/GoogleGroupsPython.
>
> Mark Lawrence
>
> --
> http://mail.python.org/mailman/listinfo/python-list

Agreed. And you should work on WSGI support too.
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From usenetmail at solar-empire.de  Sun May 26 06:06:39 2013
From: usenetmail at solar-empire.de (Marc Christiansen)
Date: Sun, 26 May 2013 12:06:39 +0200
Subject: CrazyHTTPd - HTTP Daemon in Python
References: <ba07afc2-41c7-4c42-b4e7-75f39bf7bda0@googlegroups.com>
	<mailman.2160.1369541183.3114.python-list@python.org>
Message-ID: <fe397a-87s.ln1@pluto.solar-empire.de>

Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 26/05/2013 04:55, cdorm245 at gmail.com wrote:
>> This is a small little Project that I have started. Its a light
>> little Web Server (HTTPd) coded in python. Requirements: Python 2.7
>> =< And Linux / BSD. I believe this could work in a CLI Emulator in
>> windows too.
>> Welcome to check out the website powered by CrazyHTTPd:
>> http://web.crazycoder.me:14081/index.html
>>
>> Please Email me with any bugs, errors, and/or comments about my
>> little project: cdorm245 at gmail.com
>>
> 
> IMHO writing a project right now that is limited to Python 2 is about as 
> much use as a chocolate teapot.

I.e. not very useful, but slightly more so than you would expect:
http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/how-useless-is-a-chocolate-teapot/

Adia?
Marc


From nikos.gr33k at gmail.com  Sun May 26 04:08:39 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 01:08:39 -0700 (PDT)
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and 'tuple'
Message-ID: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>

Hello this is the following snippet that is causing me the error i mention in the Subject:


	try:
		cur.execute( '''SELECT url, hits FROM counters ORDER BY hits DESC''' )

		data = cur.fetchall()
		for row in data:
			(url, hits) = row
			
			print( "<tr><td><center><a href='http://superhost.gr/?show=log&page=%s'><font color=tomato size=5> %s </a></td>" ) % (url, url)
			print( "<td><center><font color=cyan size=5> %s </a></td></tr>" ) % (hits)
	except pymysql.ProgrammingError as e:
		print( repr(e) )


you can slso see it at:

http://superhost.gr/?show=stats


From __peter__ at web.de  Sun May 26 04:23:40 2013
From: __peter__ at web.de (Peter Otten)
Date: Sun, 26 May 2013 10:23:40 +0200
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
Message-ID: <knsgp0$mvh$1@ger.gmane.org>

????? ???33? wrote:

> Hello this is the following snippet that is causing me the error i mention
> in the Subject:

> print( "<tr><td><center><a href='http://superhost.gr/?show=log&page=%s'><font color=tomato size=5> %s </a></td>" ) % (url, url)

Hint (Python 3):

>>> print("a=%s, b=%s") % (1, 2)
a=%s, b=%s
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for %: 'NoneType' and 'tuple'

>>> print("a=%s, b=%s" % (1, 2))
a=1, b=2




From nikos.gr33k at gmail.com  Sun May 26 05:12:51 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 02:12:51 -0700 (PDT)
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <mailman.2169.1369556595.3114.python-list@python.org>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<mailman.2169.1369556595.3114.python-list@python.org>
Message-ID: <eb43bee9-199b-49ec-a257-c72c9fc9ebce@googlegroups.com>

?? ???????, 26 ????? 2013 11:23:40 ?.?. UTC+3, ? ??????? Peter Otten ??????:
> ????? ???33? wrote:
> 
> 
> 
> > Hello this is the following snippet that is causing me the error i mention
> 
> > in the Subject:
> 
> 
> 
> > print( "<tr><td><center><a href='http://superhost.gr/?show=log&page=%s'><font color=tomato size=5> %s </a></td>" ) % (url, url)
> 
> 
> 
> Hint (Python 3):
> 
> 
> 
> >>> print("a=%s, b=%s") % (1, 2)
> 
> a=%s, b=%s
> 
> Traceback (most recent call last):
> 
>   File "<stdin>", line 1, in <module>
> 
> TypeError: unsupported operand type(s) for %: 'NoneType' and 'tuple'

> >>> print("a=%s, b=%s" % (1, 2))
> 
> a=1, b=2

Thank you very much Peter, so as it seems in Python 3.3.1 all substitutuons must be nested in print().


From __peter__ at web.de  Sun May 26 05:25:17 2013
From: __peter__ at web.de (Peter Otten)
Date: Sun, 26 May 2013 11:25:17 +0200
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<mailman.2169.1369556595.3114.python-list@python.org>
	<eb43bee9-199b-49ec-a257-c72c9fc9ebce@googlegroups.com>
Message-ID: <knskcg$jsi$1@ger.gmane.org>

????? ???33? wrote:

> Thank you very much Peter, so as it seems in Python 3.3.1 all
> substitutuons must be nested in print().

Yes; in other words: 

In Python 3 print() is a function.




From nikos.gr33k at gmail.com  Sun May 26 06:32:18 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 03:32:18 -0700 (PDT)
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <mailman.2171.1369560291.3114.python-list@python.org>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<mailman.2169.1369556595.3114.python-list@python.org>
	<eb43bee9-199b-49ec-a257-c72c9fc9ebce@googlegroups.com>
	<mailman.2171.1369560291.3114.python-list@python.org>
Message-ID: <09f62f17-9a36-4b8c-a7db-e0dfd95ec5c4@googlegroups.com>

Perhaps cna you help a bit with tha too:
used to work in 2.6 but not with 3.3.1

#!/usr/bin/python3
# coding=utf-8

import cgitb; cgitb.enable()
import cgi, os, sys
from http import cookies


# initialize cookie
cookie = cookies.SimpleCookie( os.environ.get('HTTP_COOKIE') )
cookie.load( cookie )
nikos = cookie.get('nikos')


# if visitor cookie does exist
if nikos:
	msg = "??? ??? ??????? ???????? ??? ?? ?? ????????? ?? ????????? ?????????? ??? ???????!"
	cookie['nikos'] = 'admin'
	cookie['nikos']['path'] = '/'
	cookie['nikos']['expires'] = -1		#this cookie will expire now
else:
	msg = "??? ?? ??? ??? ???? ??? ?? ????, ??? ?? ????, ??? ?? ??????! ?? ????? ????? ? ??????? ??????????!!"
	cookie['nikos'] = 'admin'
	cookie['nikos']['path'] = '/'
	cookie['nikos']['expires'] = 60*60*24*30*12		#this cookie will expire in a year


print ( "Content-type: text/html; charset=utf-8\n" )
print( cookie, msg )
sys.exit(0)

ima getting internal server error.


From nikos.gr33k at gmail.com  Sun May 26 09:00:51 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 06:00:51 -0700 (PDT)
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
Message-ID: <dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>

Anyone seeign somethign wrong?


From rosuav at gmail.com  Sun May 26 09:10:02 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 23:10:02 +1000
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
Message-ID: <CAPTjJmooVCP=FgyF7DDAtY-YESLY_q6mGc0CFefM2H5TtauuHA@mail.gmail.com>

On Sun, May 26, 2013 at 11:00 PM, ????? ???33? <nikos.gr33k at gmail.com> wrote:
> Anyone seeign somethign wrong?

Yes. You're posting requests, then bumping the thread two hours later
as though you're entitled to a response quicker than that. Plus, the
problems you're seeing ought to be solved by the 2to3 utility. Use it.
Look at its output.

ChrisA


From carlosnepomuceno at outlook.com  Sun May 26 10:23:59 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 17:23:59 +0300
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>,
	<dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
Message-ID: <BLU176-W1010E70553F6B2949A998BD7950@phx.gbl>

----------------------------------------
> Date: Sun, 26 May 2013 06:00:51 -0700
> Subject: Re: TypeError: unsupported operand type(s) for %: 'NoneType' and 'tuple'
> From: nikos.gr33k at gmail.com
> To: python-list at python.org
>
> Anyone seeign somethign wrong?
> --
> http://mail.python.org/mailman/listinfo/python-list

I don't know any module 'http' in Python standard library.

Think you mean the 'http.cookies' module in Python 3. 		 	   		  

From nagia.retsina at gmail.com  Sun May 26 11:00:18 2013
From: nagia.retsina at gmail.com (nagia.retsina at gmail.com)
Date: Sun, 26 May 2013 08:00:18 -0700 (PDT)
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <mailman.2173.1369573812.3114.python-list@python.org>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
	<mailman.2173.1369573812.3114.python-list@python.org>
Message-ID: <d14aab24-a1c7-43e5-9046-d515858bfd1b@googlegroups.com>

?? ???????, 26 ????? 2013 4:10:02 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
> On Sun, May 26, 2013 at 11:00 PM, ????? ???33? <nikos.gr33k at gmail.com> wrote:
> 
> > Anyone seeign somethign wrong?
> 
> 
> 
> Yes. You're posting requests, then bumping the thread two hours later
> 
> as though you're entitled to a response quicker than that. Plus, the
> 
> problems you're seeing ought to be solved by the 2to3 utility. Use it.
> 
> Look at its output.
> 
> 
> 
> ChrisA

There is a tool that convert python 2.6.x code => python 3.x ?

Can you post a link to that toll plz?


From rosuav at gmail.com  Sun May 26 11:24:55 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 01:24:55 +1000
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <d14aab24-a1c7-43e5-9046-d515858bfd1b@googlegroups.com>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
	<mailman.2173.1369573812.3114.python-list@python.org>
	<d14aab24-a1c7-43e5-9046-d515858bfd1b@googlegroups.com>
Message-ID: <CAPTjJmrK0vCk2_z6bcy_Dt_-op3TvbPMbXjsZhLDJ1FqAeV81g@mail.gmail.com>

On Mon, May 27, 2013 at 1:00 AM,  <nagia.retsina at gmail.com> wrote:
> ?? ???????, 26 ????? 2013 4:10:02 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
>> On Sun, May 26, 2013 at 11:00 PM, ????? ???33? <nikos.gr33k at gmail.com> wrote:
>>
>> > Anyone seeign somethign wrong?
>>
>>
>>
>> Yes. You're posting requests, then bumping the thread two hours later
>>
>> as though you're entitled to a response quicker than that. Plus, the
>>
>> problems you're seeing ought to be solved by the 2to3 utility. Use it.
>>
>> Look at its output.
>>
>>
>>
>> ChrisA
>
> There is a tool that convert python 2.6.x code => python 3.x ?
>
> Can you post a link to that toll plz?

You have its name. You have Google. You have a mailing list that is
getting tired of you not putting in any effort.

ChrisA


From breamoreboy at yahoo.co.uk  Sun May 26 12:43:33 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 17:43:33 +0100
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <CAPTjJmrK0vCk2_z6bcy_Dt_-op3TvbPMbXjsZhLDJ1FqAeV81g@mail.gmail.com>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
	<mailman.2173.1369573812.3114.python-list@python.org>
	<d14aab24-a1c7-43e5-9046-d515858bfd1b@googlegroups.com>
	<CAPTjJmrK0vCk2_z6bcy_Dt_-op3TvbPMbXjsZhLDJ1FqAeV81g@mail.gmail.com>
Message-ID: <knte34$ru8$1@ger.gmane.org>

On 26/05/2013 16:24, Chris Angelico wrote:
> On Mon, May 27, 2013 at 1:00 AM,  <nagia.retsina at gmail.com> wrote:
>> ?? ???????, 26 ????? 2013 4:10:02 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
>>> On Sun, May 26, 2013 at 11:00 PM, ????? ???33? <nikos.gr33k at gmail.com> wrote:
>>>
>>>> Anyone seeign somethign wrong?
>>>
>>>
>>>
>>> Yes. You're posting requests, then bumping the thread two hours later
>>>
>>> as though you're entitled to a response quicker than that. Plus, the
>>>
>>> problems you're seeing ought to be solved by the 2to3 utility. Use it.
>>>
>>> Look at its output.
>>>
>>>
>>>
>>> ChrisA
>>
>> There is a tool that convert python 2.6.x code => python 3.x ?
>>
>> Can you post a link to that toll plz?
>
> You have its name. You have Google. You have a mailing list that is
> getting tired of you not putting in any effort.
>
> ChrisA
>

Not to mention double spaced google crap :(

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From nikos.gr33k at gmail.com  Sun May 26 11:45:59 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 08:45:59 -0700 (PDT)
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <mailman.2176.1369581898.3114.python-list@python.org>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
	<mailman.2173.1369573812.3114.python-list@python.org>
	<d14aab24-a1c7-43e5-9046-d515858bfd1b@googlegroups.com>
	<mailman.2176.1369581898.3114.python-list@python.org>
Message-ID: <7d1d3a51-6f83-4a4e-9083-c60c581af4f1@googlegroups.com>

?? ???????, 26 ????? 2013 6:24:55 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
> On Mon, May 27, 2013 at 1:00 AM,  <nagia.retsina at gmail.com> wrote:
> 
> > ?? ???????, 26 ????? 2013 4:10:02 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
> 
> >> On Sun, May 26, 2013 at 11:00 PM, ????? ???33? <nikos.gr33k at gmail.com> wrote:
> 
> >>
> 
> >> > Anyone seeign somethign wrong?
> 
> >>
> 
> >>
> 
> >>
> 
> >> Yes. You're posting requests, then bumping the thread two hours later
> 
> >>
> 
> >> as though you're entitled to a response quicker than that. Plus, the
> 
> >>
> 
> >> problems you're seeing ought to be solved by the 2to3 utility. Use it.
> 
> >>
> 
> >> Look at its output.
> 
> >>
> 
> >>
> 
> >>
> 
> >> ChrisA
> 
> >
> 
> > There is a tool that convert python 2.6.x code => python 3.x ?
> 
> >
> 
> > Can you post a link to that toll plz?
> 
> 
> 
> You have its name. You have Google. You have a mailing list that is
> 
> getting tired of you not putting in any effort.
> 
> 
> 
> ChrisA

Yes i saw it its name is 2to3 conversion but my code is already written in python3

i ahve written in line byu line from sctatrch ,much like pelatologio.py
which when i intreprtet in via cmd i get no errors.

i dont understand why iam receiving  an internal server error for both in browser mdoe though.


From nikos.gr33k at gmail.com  Sun May 26 12:10:10 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 09:10:10 -0700 (PDT)
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <7d1d3a51-6f83-4a4e-9083-c60c581af4f1@googlegroups.com>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
	<mailman.2173.1369573812.3114.python-list@python.org>
	<d14aab24-a1c7-43e5-9046-d515858bfd1b@googlegroups.com>
	<mailman.2176.1369581898.3114.python-list@python.org>
	<7d1d3a51-6f83-4a4e-9083-c60c581af4f1@googlegroups.com>
Message-ID: <6cb9f223-d114-40aa-bf13-314b65c327b7@googlegroups.com>

Here is the live error log coming form apacher when i request the webpage form browser:

==> /usr/local/apache/logs/error_log <==
[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] suexec failure: could not open log file
[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] fopen: Permission denied
[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] fopen: Permission denied
[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py
[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py

what is that suexec?


From breamoreboy at yahoo.co.uk  Sun May 26 12:45:42 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 17:45:42 +0100
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <6cb9f223-d114-40aa-bf13-314b65c327b7@googlegroups.com>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
	<mailman.2173.1369573812.3114.python-list@python.org>
	<d14aab24-a1c7-43e5-9046-d515858bfd1b@googlegroups.com>
	<mailman.2176.1369581898.3114.python-list@python.org>
	<7d1d3a51-6f83-4a4e-9083-c60c581af4f1@googlegroups.com>
	<6cb9f223-d114-40aa-bf13-314b65c327b7@googlegroups.com>
Message-ID: <knte75$ru8$2@ger.gmane.org>

On 26/05/2013 17:10, ????? ???33? wrote:
> Here is the live error log coming form apacher when i request the webpage form browser:
>
> ==> /usr/local/apache/logs/error_log <==
> [Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] suexec failure: could not open log file
> [Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] fopen: Permission denied
> [Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] fopen: Permission denied
> [Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py
> [Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py
>
> what is that suexec?
>

What has this got to do with Python?

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From cs at zip.com.au  Sun May 26 20:26:29 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 27 May 2013 10:26:29 +1000
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <knte75$ru8$2@ger.gmane.org>
References: <knte75$ru8$2@ger.gmane.org>
Message-ID: <20130527002629.GA27910@cskk.homeip.net>

On 26May2013 17:45, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
| On 26/05/2013 17:10, ????? ???33? wrote:
| >Here is the live error log coming form apacher when i request the webpage form browser:
| >
| >==> /usr/local/apache/logs/error_log <==
| >[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] suexec failure: could not open log file
| >[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] fopen: Permission denied
| >[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] fopen: Permission denied
| >[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py
| >[Sun May 26 19:07:41 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py
| >
| >what is that suexec?
| 
| What has this got to do with Python?

Little, and I've already explained what suexec is to him some weeks ago, off list.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

The road less traveled is FASTER !!
        - Luc Marcouiller, marcouil at ireq.hydro.qc.ca


From nikos.gr33k at gmail.com  Tue May 28 02:01:35 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Mon, 27 May 2013 23:01:35 -0700 (PDT)
Subject: TypeError: unsupported operand type(s) for %: 'NoneType' and
	'tuple'
In-Reply-To: <mailman.2182.1369587005.3114.python-list@python.org>
References: <ffb99274-6844-4638-bb4b-4312c0b246c2@googlegroups.com>
	<dd801121-31f6-4df8-a99e-d981bb507c47@googlegroups.com>
	<mailman.2173.1369573812.3114.python-list@python.org>
	<d14aab24-a1c7-43e5-9046-d515858bfd1b@googlegroups.com>
	<mailman.2176.1369581898.3114.python-list@python.org>
	<7d1d3a51-6f83-4a4e-9083-c60c581af4f1@googlegroups.com>
	<6cb9f223-d114-40aa-bf13-314b65c327b7@googlegroups.com>
	<mailman.2182.1369587005.3114.python-list@python.org>
Message-ID: <9e932231-d7e8-439f-84e9-a71246c2b773@googlegroups.com>

?? ???????, 26 ????? 2013 7:45:42 ?.?. UTC+3, ? ??????? Mark Lawrence ??????:

> What has this got to do with Python?

What do your questions have to do with a proper reply?


From abdulshafy at gmail.com  Sun May 26 07:11:56 2013
From: abdulshafy at gmail.com (Ahmed Abdulshafy)
Date: Sun, 26 May 2013 04:11:56 -0700 (PDT)
Subject: Short-circuit Logic
Message-ID: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>

Hi,
I'm having a hard time wrapping my head around short-circuit logic that's used by Python, coming from a C/C++ background; so I don't understand why the following condition is written this way!>

     if not allow_zero and abs(x) < sys.float_info.epsilon:
                print("zero is not allowed")

The purpose of this snippet is to print the given line when allow_zero is False and x is 0.


From roy at panix.com  Sun May 26 07:38:38 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 26 May 2013 07:38:38 -0400
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
Message-ID: <roy-370944.07383826052013@news.panix.com>

In article <5f101d70-e51f-4531-9153-c92ee2486fd9 at googlegroups.com>,
 Ahmed Abdulshafy <abdulshafy at gmail.com> wrote:

> Hi,
> I'm having a hard time wrapping my head around short-circuit logic that's 
> used by Python, coming from a C/C++ background; so I don't understand why the 
> following condition is written this way!>
> 
>      if not allow_zero and abs(x) < sys.float_info.epsilon:
>                 print("zero is not allowed")
> 
> The purpose of this snippet is to print the given line when allow_zero is 
> False and x is 0.

I don't understand your confusion.  Short-circuit evaluation works in 
Python exactly the same way it works in C.  When you have a boolean 
operation, the operands are evaluated left-to-right, and evaluation 
stops as soon as the truth value of the expression is known.

In C, you would write:

   if (p && p->foo) {
        blah();
    }

to make sure that you don't dereference a null pointer.  A similar 
example in Python might be:

    if d and d["foo"]:
        blah()

which protects against trying to access an element of a dictionary if 
the dictionary is None (which might happen if d was an optional argument 
to a method and wasn't passed on this invocation).

But, none of that applies to your example.  The condition is

    not allow_zero and abs(x) < sys.float_info.epsilon:

it's safe to evaluate "abs(x) < sys.float_info.epsilon" no matter what 
the value of "not allow_zero".  For the purposes of understanding your 
code, you can pretend that short-circuit evaluation doesn't exist!

So, what is your code doing that you don't understand?


From steve+comp.lang.python at pearwood.info  Sun May 26 08:13:47 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 26 May 2013 12:13:47 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
Message-ID: <51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Sun, 26 May 2013 04:11:56 -0700, Ahmed Abdulshafy wrote:

> Hi,
> I'm having a hard time wrapping my head around short-circuit logic
> that's used by Python, coming from a C/C++ background; so I don't
> understand why the following condition is written this way!
> 
>      if not allow_zero and abs(x) < sys.float_info.epsilon:
>                 print("zero is not allowed")

Follow the logic.

If allow_zero is a true value, then "not allow_zero" is False, and the 
"and" clause cannot evaluate to true. (False and X is always False.) So 
print is not called.

If allow_zero is a false value, then "not allow_zero" is True, and the 
"and" clause depends on the second argument. (True and X is always X.) So
abs(x) < sys.float_info.epsilon is tested, and if that is True, print is 
called.

By the way, I don't think much of this logic. Values smaller than epsilon 
are not necessarily zero:

py> import sys
py> epsilon = sys.float_info.epsilon
py> x = epsilon/10000
py> x == 0
False
py> x * 3 == 0
False
py> x + epsilon == 0
False
py> x + epsilon == epsilon
False

The above logic throws away many perfectly good numbers and treats them 
as zero even though they aren't.


> The purpose of this snippet is to print the given line when allow_zero
> is False and x is 0.

Then the snippet utterly fails at that, since it prints the line for many 
values of x which can be distinguished from zero. The way to test whether 
x equals zero is:

x == 0

What the above actually tests for is whether x is so small that (1.0+x) 
cannot be distinguished from 1.0, which is not the same thing. It is also 
quite arbitrary. Why 1.0? Why not (0.0001+x)? Or (0.00000001+x)? Or 
(10000.0+x)?



-- 
Steven


From abdulshafy at gmail.com  Mon May 27 16:11:28 2013
From: abdulshafy at gmail.com (Ahmed Abdulshafy)
Date: Mon, 27 May 2013 13:11:28 -0700 (PDT)
Subject: Short-circuit Logic
In-Reply-To: <51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>

On Sunday, May 26, 2013 2:13:47 PM UTC+2, Steven D'Aprano wrote:
> On Sun, 26 May 2013 04:11:56 -0700, Ahmed Abdulshafy wrote:
> 
> 
> 
> > Hi,
> 
> > I'm having a hard time wrapping my head around short-circuit logic
> 
> > that's used by Python, coming from a C/C++ background; so I don't
> 
> > understand why the following condition is written this way!
> 
> > 
> 
> >      if not allow_zero and abs(x) < sys.float_info.epsilon:
> 
> >                 print("zero is not allowed")
> 
> 
> 
> Follow the logic.
> 
> 
> 
> If allow_zero is a true value, then "not allow_zero" is False, and the 
> 
> "and" clause cannot evaluate to true. (False and X is always False.) So 
> 
> print is not called.
> 
> 
> 
> If allow_zero is a false value, then "not allow_zero" is True, and the 
> 
> "and" clause depends on the second argument. (True and X is always X.) So
> 
> abs(x) < sys.float_info.epsilon is tested, and if that is True, print is 
> 
> called.
> 
> 
> 
> By the way, I don't think much of this logic. Values smaller than epsilon 
> 
> are not necessarily zero:
> 
> 
> 
> py> import sys
> 
> py> epsilon = sys.float_info.epsilon
> 
> py> x = epsilon/10000
> 
> py> x == 0
> 
> False
> 
> py> x * 3 == 0
> 
> False
> 
> py> x + epsilon == 0
> 
> False
> 
> py> x + epsilon == epsilon
> 
> False
> 
> 
> 
> The above logic throws away many perfectly good numbers and treats them 
> 
> as zero even though they aren't.
> 
> 
> 
> 
> 
> > The purpose of this snippet is to print the given line when allow_zero
> 
> > is False and x is 0.
> 
> 
> 
> Then the snippet utterly fails at that, since it prints the line for many 
> 
> values of x which can be distinguished from zero. The way to test whether 
> 
> x equals zero is:
> 
> 
> 
> x == 0
> 
> 
> 
> What the above actually tests for is whether x is so small that (1.0+x) 
> 
> cannot be distinguished from 1.0, which is not the same thing. It is also 
> 
> quite arbitrary. Why 1.0? Why not (0.0001+x)? Or (0.00000001+x)? Or 
> 
> (10000.0+x)?
> 
> 
> 
> 
> 
> 
> 
> -- 
> 
> Steven

That may be true for integers, but for floats, testing for equality is not always precise


From nobody at nowhere.com  Mon May 27 20:10:05 2013
From: nobody at nowhere.com (Nobody)
Date: Tue, 28 May 2013 01:10:05 +0100
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
Message-ID: <pan.2013.05.28.00.10.04.235000@nowhere.com>

On Mon, 27 May 2013 13:11:28 -0700, Ahmed Abdulshafy wrote:

> On Sunday, May 26, 2013 2:13:47 PM UTC+2, Steven D'Aprano wrote:
>
>> What the above actually tests for is whether x is so small that (1.0+x)
>> cannot be distinguished from 1.0, which is not the same thing. It is
>> also quite arbitrary. Why 1.0? Why not (0.0001+x)? Or (0.00000001+x)?
>> Or (10000.0+x)?
> 
> That may be true for integers,

What may be true for integers?

> but for floats, testing for equality is not always precise

And your point is?

What Steven wrote is entirely correct: sys.float_info.epsilon is the
smallest value x such that 1.0 and 1.0+x have distinct floating-point
representations. It has no relevance for comparing to zero.



From abdulshafy at gmail.com  Tue May 28 04:39:09 2013
From: abdulshafy at gmail.com (Ahmed Abdulshafy)
Date: Tue, 28 May 2013 01:39:09 -0700 (PDT)
Subject: Short-circuit Logic
In-Reply-To: <pan.2013.05.28.00.10.04.235000@nowhere.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<pan.2013.05.28.00.10.04.235000@nowhere.com>
Message-ID: <48a99056-fa56-4352-b8b4-f52d3467ac96@googlegroups.com>

On Tuesday, May 28, 2013 2:10:05 AM UTC+2, Nobody wrote:
> On Mon, 27 May 2013 13:11:28 -0700, Ahmed Abdulshafy wrote:
> 
> 
> 
> > On Sunday, May 26, 2013 2:13:47 PM UTC+2, Steven D'Aprano wrote:
> 
> >
> 
> >> What the above actually tests for is whether x is so small that (1.0+x)
> 
> >> cannot be distinguished from 1.0, which is not the same thing. It is
> 
> >> also quite arbitrary. Why 1.0? Why not (0.0001+x)? Or (0.00000001+x)?
> 
> >> Or (10000.0+x)?
> 
> > 
> 
> > That may be true for integers,
> 
> 
> 
> What may be true for integers?
> 
> 
> 
> > but for floats, testing for equality is not always precise
> 
> 
> 
> And your point is?
> 
> 
> 
> What Steven wrote is entirely correct: sys.float_info.epsilon is the
> 
> smallest value x such that 1.0 and 1.0+x have distinct floating-point
> 
> representations. It has no relevance for comparing to zero.

He just said that the way to test for zero equality is x == 0, and I meant that this is true for integers but not necessarily for floats. And that's not specific to Python.


From carlosnepomuceno at outlook.com  Tue May 28 05:32:20 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 12:32:20 +0300
Subject: Short-circuit Logic
In-Reply-To: <48a99056-fa56-4352-b8b4-f52d3467ac96@googlegroups.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>,
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>,
	<pan.2013.05.28.00.10.04.235000@nowhere.com>,
	<48a99056-fa56-4352-b8b4-f52d3467ac96@googlegroups.com>
Message-ID: <BLU176-W39A26F8276C497ED3A2C98D7970@phx.gbl>

----------------------------------------
> Date: Tue, 28 May 2013 01:39:09 -0700
> Subject: Re: Short-circuit Logic
> From: abdulshafy at gmail.com
[...]
>> What Steven wrote is entirely correct: sys.float_info.epsilon is the
>>
>> smallest value x such that 1.0 and 1.0+x have distinct floating-point
>>
>> representations. It has no relevance for comparing to zero.
>
> He just said that the way to test for zero equality is x == 0, and I meant that this is true for integers but not necessarily for floats. And that's not specific to Python.


Have you read [1]? There's a section "Infernal Zero" that discuss this problem. I think it's very interesting to know! ;)

Just my 49.99999999999998?! lol


[1] http://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/ 		 	   		  

From breamoreboy at yahoo.co.uk  Tue May 28 07:45:21 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 28 May 2013 12:45:21 +0100
Subject: Short-circuit Logic
In-Reply-To: <48a99056-fa56-4352-b8b4-f52d3467ac96@googlegroups.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<pan.2013.05.28.00.10.04.235000@nowhere.com>
	<48a99056-fa56-4352-b8b4-f52d3467ac96@googlegroups.com>
Message-ID: <ko25br$8fq$1@ger.gmane.org>

On 28/05/2013 09:39, Ahmed Abdulshafy wrote:
>
> And that's not specific to Python.
>

Using google products is also not specific to Python.  However whereever 
it's used it's a PITA as people are forced into reading double spaced 
crap.  Please check out the link in my signature.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Tue May 28 09:51:37 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 28 May 2013 13:51:37 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<pan.2013.05.28.00.10.04.235000@nowhere.com>
	<48a99056-fa56-4352-b8b4-f52d3467ac96@googlegroups.com>
Message-ID: <51a4b669$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Tue, 28 May 2013 01:39:09 -0700, Ahmed Abdulshafy wrote:

> He just said that the way to test for zero equality is x == 0, and I
> meant that this is true for integers but not necessarily for floats. And
> that's not specific to Python.

Can you show me a value of x where x == 0.0 returns False, but x actually 
isn't zero?

Built-in floats only, if you subclass you can do anything you like:

class Cheating(float):
    def __eq__(self, other):
        return False


-- 
Steven



From invalid at invalid.invalid  Tue May 28 11:14:03 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 15:14:03 +0000 (UTC)
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<pan.2013.05.28.00.10.04.235000@nowhere.com>
	<48a99056-fa56-4352-b8b4-f52d3467ac96@googlegroups.com>
	<51a4b669$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ko2hjr$i4q$2@reader1.panix.com>

On 2013-05-28, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> On Tue, 28 May 2013 01:39:09 -0700, Ahmed Abdulshafy wrote:
>
>> He just said that the way to test for zero equality is x == 0, and I
>> meant that this is true for integers but not necessarily for floats. And
>> that's not specific to Python.
>
> Can you show me a value of x where x == 0.0 returns False, but x actually 
> isn't zero?

I'm confused.  Don't all non-zero values satisfy your conditions?

>>> x = 1.0
>>> x == 0.0
False
>>> x is 0.0
False



-- 
Grant Edwards               grant.b.edwards        Yow! I'm dressing up in
                                  at               an ill-fitting IVY-LEAGUE
                              gmail.com            SUIT!!  Too late...


From steve+comp.lang.python at pearwood.info  Tue May 28 11:55:42 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 28 May 2013 15:55:42 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<pan.2013.05.28.00.10.04.235000@nowhere.com>
	<48a99056-fa56-4352-b8b4-f52d3467ac96@googlegroups.com>
	<51a4b669$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<ko2hjr$i4q$2@reader1.panix.com>
Message-ID: <51a4d37e$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Tue, 28 May 2013 15:14:03 +0000, Grant Edwards wrote:

> On 2013-05-28, Steven D'Aprano <steve+comp.lang.python at pearwood.info>
> wrote:
>> On Tue, 28 May 2013 01:39:09 -0700, Ahmed Abdulshafy wrote:
>>
>>> He just said that the way to test for zero equality is x == 0, and I
>>> meant that this is true for integers but not necessarily for floats.
>>> And that's not specific to Python.
>>
>> Can you show me a value of x where x == 0.0 returns False, but x
>> actually isn't zero?
> 
> I'm confused.  Don't all non-zero values satisfy your conditions?

Of course they do :-(

I meant "but x actually *is* zero". Sorry for the confusion. I blame the 
terrists.



-- 
Steven


From steve+comp.lang.python at pearwood.info  Tue May 28 09:48:17 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 28 May 2013 13:48:17 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
Message-ID: <51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Mon, 27 May 2013 13:11:28 -0700, Ahmed Abdulshafy wrote:

> That may be true for integers, but for floats, testing for equality is
> not always precise

Incorrect. Testing for equality is always precise, and exact. The problem 
is not the *equality test*, but that you don't always have the number 
that you think you have. The problem lies elsewhere, not equality!
Unfortunately, people who say "never test floats for equality" have 
misdiagnosed the problem, or they are giving a simple work-around which 
can be misleading to those who don't understand what is actually going on.

Any floating point libraries that support IEEE-754 semantics can 
guarantee a few things, including:

x == 0.0 if, and only if, x actually equals zero.

This was not always the case for all floating point systems prior to 
IEEE-754. In his forward to the Apple Numerics Manual, William Kahan 
describes a Capriciously Designed Computer where 1/x can give a Division 
By Zero error even though x != 0. Fortunately, if you are programming in 
Python on Intel-compatible hardware, you do not have to worry about 
nightmares like that.

Let me repeat that: in Python, you can trust that if x == 0.0 returns 
False, then x is definitely not zero.

In any case, the test that you show is not a good test. I have already 
shown that it wrongly treats many non-zero numbers which can be 
distinguished from zero as if they were zero. But worse, it also fails as 
a guard against numbers which cannot be distinguished from zero!

py> import sys
py> epsilon = sys.float_info.epsilon
py> x < epsilon  # Is x so tiny it looks like zero?
False
py> y = 1e17 + x  # x is not zero, so y should be > 1e17
py> 1/(1e17 - y)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ZeroDivisionError: float division by zero


So as you can see, testing for "zero" by comparing to machine epsilon 
does not save you from Zero Division errors.


-- 
Steven


From rosuav at gmail.com  Tue May 28 10:01:01 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 29 May 2013 00:01:01 +1000
Subject: Short-circuit Logic
In-Reply-To: <51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmoXsK8MvQ4=F-dsLC=8Y27v7Z+5V4UT5cWFWV4vwdDLmA@mail.gmail.com>

On Tue, May 28, 2013 at 11:48 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> py> y = 1e17 + x  # x is not zero, so y should be > 1e17
> py> 1/(1e17 - y)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> ZeroDivisionError: float division by zero

You don't even need to go for 1e17. By definition:

>>> sys.float_info.epsilon+1.0==1.0
False
>>> sys.float_info.epsilon+2.0==2.0
True

Therefore the same can be done with 2 as you did with 1e17.

>>> y = 2 + sys.float_info.epsilon
>>> 1/(2-y)
Traceback (most recent call last):
  File "<pyshell#182>", line 1, in <module>
    1/(2-y)
ZeroDivisionError: float division by zero

Of course, since we're working with a number greater than epsilon, we
need to go a little further, but we can still work with small numbers:

>>> x = sys.float_info.epsilon * 2   # Definitely greater than epsilon
>>> y = 4 + x
>>> 1/(4-y)
Traceback (most recent call last):
  File "<pyshell#191>", line 1, in <module>
    1/(4-y)
ZeroDivisionError: float division by zero


ChrisA


From abdulshafy at gmail.com  Wed May 29 10:27:40 2013
From: abdulshafy at gmail.com (Ahmed Abdulshafy)
Date: Wed, 29 May 2013 07:27:40 -0700 (PDT)
Subject: Short-circuit Logic
In-Reply-To: <51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>

On Tuesday, May 28, 2013 3:48:17 PM UTC+2, Steven D'Aprano wrote:
> On Mon, 27 May 2013 13:11:28 -0700, Ahmed Abdulshafy wrote:
> 
> 
> 
> > That may be true for integers, but for floats, testing for equality is
> 
> > not always precise
> 
> 
> 
> Incorrect. Testing for equality is always precise, and exact. The problem 
> 
> is not the *equality test*, but that you don't always have the number 
> 
> that you think you have. The problem lies elsewhere, not equality!
> 
> 
> Steven

Well, this is taken from my python shell>

>>> 0.33455857352426283 == 0.33455857352426282
True

Anyway, man, those were not my words anyway, most programming books I've read state so. Here's an excerpt from the Python book, I'm currently reading>

">>> 0.0, 5.4, -2.5, 8.9e-4
(0.0, 5.4000000000000004, -2.5, 0.00088999999999999995)


The inexactness is not a problem specific to Python?all programming languages have this problem with floating-point numbers."


From rosuav at gmail.com  Wed May 29 10:32:34 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 00:32:34 +1000
Subject: Short-circuit Logic
In-Reply-To: <04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
Message-ID: <CAPTjJmr9C7dOZ9XcuynQnKx5Ty5nQPLbaG+4jxMJUZYbZ-DNLA@mail.gmail.com>

On Thu, May 30, 2013 at 12:27 AM, Ahmed Abdulshafy <abdulshafy at gmail.com> wrote:
> Well, this is taken from my python shell>
>
>>>> 0.33455857352426283 == 0.33455857352426282
> True


>>> 0.33455857352426283,0.33455857352426282
(0.3345585735242628, 0.3345585735242628)

They're not representably different.

ChrisA


From rustompmody at gmail.com  Wed May 29 10:33:39 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 29 May 2013 07:33:39 -0700 (PDT)
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
Message-ID: <48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>

On May 29, 7:27?pm, Ahmed Abdulshafy <abdulsh... at gmail.com> wrote:
> On Tuesday, May 28, 2013 3:48:17 PM UTC+2, Steven D'Aprano wrote:
> > On Mon, 27 May 2013 13:11:28 -0700, Ahmed Abdulshafy wrote:
>
> > > That may be true for integers, but for floats, testing for equality is
>
> > > not always precise
>
> > Incorrect. Testing for equality is always precise, and exact. The problem
>
> > is not the *equality test*, but that you don't always have the number
>
> > that you think you have. The problem lies elsewhere, not equality!
>
> > Steven
>
> Well, this is taken from my python shell>
>
> >>> 0.33455857352426283 == 0.33455857352426282
>
> True
>
> Anyway, man, those were not my words anyway, most programming books I've read state so. Here's an excerpt from the Python book, I'm currently reading>
>
> ">>> 0.0, 5.4, -2.5, 8.9e-4
> (0.0, 5.4000000000000004, -2.5, 0.00088999999999999995)
>
> The inexactness is not a problem specific to Python?all programming languages have this problem with floating-point numbers."

0.0 == 0.0 implies 5.4 == 5.4
is not a true statement is what (I think) Steven is saying.
0 (or if you prefer 0.0) is special and is treated specially.

Naturally if you reach (nearabout) 0.0 by some numerical process thats
another matter...


From ian.g.kelly at gmail.com  Wed May 29 12:50:47 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 29 May 2013 10:50:47 -0600
Subject: Short-circuit Logic
In-Reply-To: <48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
Message-ID: <CALwzidnB+KeUiNDYQ4Yjtk7-i=h52ZXQ+pv-B0NqUgh3jC1vWA@mail.gmail.com>

On Wed, May 29, 2013 at 8:33 AM, rusi <rustompmody at gmail.com> wrote:
> 0.0 == 0.0 implies 5.4 == 5.4
> is not a true statement is what (I think) Steven is saying.
> 0 (or if you prefer 0.0) is special and is treated specially.

It has nothing to do with 0 being special.  A floating point number
will always equal itself (except for nan, which is even more special),
and in particular 5.4 == 5.4.  But if you have two different
calculations that produce 0, or two different calculations that
produce 5.4, you might actually get two different numbers that
approximate 0 or 5.4 thanks to rounding error.  If you then compare
those two ever-so-slightly different numbers, you will find them
unequal.


From davea at davea.name  Wed May 29 20:23:00 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 29 May 2013 20:23:00 -0400
Subject: Short-circuit Logic
In-Reply-To: <CALwzidnB+KeUiNDYQ4Yjtk7-i=h52ZXQ+pv-B0NqUgh3jC1vWA@mail.gmail.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<CALwzidnB+KeUiNDYQ4Yjtk7-i=h52ZXQ+pv-B0NqUgh3jC1vWA@mail.gmail.com>
Message-ID: <51A69BE4.3060003@davea.name>

On 05/29/2013 12:50 PM, Ian Kelly wrote:
> On Wed, May 29, 2013 at 8:33 AM, rusi <rustompmody at gmail.com> wrote:
>> 0.0 == 0.0 implies 5.4 == 5.4
>> is not a true statement is what (I think) Steven is saying.
>> 0 (or if you prefer 0.0) is special and is treated specially.
>
> It has nothing to do with 0 being special.  A floating point number
> will always equal itself (except for nan, which is even more special),
> and in particular 5.4 == 5.4.  But if you have two different
> calculations that produce 0, or two different calculations that
> produce 5.4, you might actually get two different numbers that
> approximate 0 or 5.4 thanks to rounding error.  If you then compare
> those two ever-so-slightly different numbers, you will find them
> unequal.
>

Rounding error is just one of the problems.  Usually less obvious is 
quantization error.  If you represent a floating number in decimal, but 
you're using a binary floating point representation, it just might change.

Another error is roundoff error.  Even in a pure decimal system of (say) 
40 digits, I could type in a 42 digit number and it would get quantized. 
  So just because two 42 digit numbers are different doesn't imply that 
the 40 digit internal format would be.


-- 
DaveA


From steve+comp.lang.python at pearwood.info  Thu May 30 01:20:42 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 05:20:42 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<CALwzidnB+KeUiNDYQ4Yjtk7-i=h52ZXQ+pv-B0NqUgh3jC1vWA@mail.gmail.com>
	<mailman.2387.1369873394.3114.python-list@python.org>
Message-ID: <51a6e1aa$0$11118$c3e8da3@news.astraweb.com>

On Wed, 29 May 2013 20:23:00 -0400, Dave Angel wrote:

> Even in a pure decimal system of (say)
> 40 digits, I could type in a 42 digit number and it would get quantized.
>   So just because two 42 digit numbers are different doesn't imply that
> the 40 digit internal format would be.

Correct, and we can demonstrate it using Python:

py> from decimal import *
py> getcontext().prec = 3
py> a = +Decimal('1.0000')
py> b = +Decimal('1.0009')
py> a == b
True


(By default, the Decimal constructor does not honour the current 
precision. To force it to do so, use the unary + operator.)
    



-- 
Steven


From steve+comp.lang.python at pearwood.info  Wed May 29 22:28:57 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 02:28:57 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
Message-ID: <51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Wed, 29 May 2013 10:50:47 -0600, Ian Kelly wrote:

> On Wed, May 29, 2013 at 8:33 AM, rusi <rustompmody at gmail.com> wrote:
>> 0.0 == 0.0 implies 5.4 == 5.4
>> is not a true statement is what (I think) Steven is saying. 0 (or if
>> you prefer 0.0) is special and is treated specially.
> 
> It has nothing to do with 0 being special.  A floating point number will
> always equal itself (except for nan, which is even more special), and in
> particular 5.4 == 5.4.  But if you have two different calculations that
> produce 0, or two different calculations that produce 5.4, you might
> actually get two different numbers that approximate 0 or 5.4 thanks to
> rounding error.  If you then compare those two ever-so-slightly
> different numbers, you will find them unequal.

EXACTLY!

The problem does not lie with the *equality operator*, it lies with the 
calculations. And that is an intractable problem -- in general, floating 
point is *hard*. So the problem occurs when we start with a perfectly 
good statement of the facts:

"If you naively test the results of a calculation for equality without 
understanding what you are doing, you will often get surprising results"

which then turns into a general heuristic that is often, but not always, 
reasonable:

"In general, you should test for floating point *approximate* equality, 
in some appropriate sense, rather than exact equality"

which then gets mangled to:

"Never test floating point numbers for equality"

and then implemented badly by people who have no clue what they are doing 
and have misunderstood the nature of the problem, leading to either:

* de facto exact equality testing, only slower and with the *illusion* of 
avoiding equality, e.g. "abs(x-y) < sys.float_info.epsilon" is just a 
long and slow way of saying "x == y" when both numbers are sufficiently 
large;

* incorrectly accepting non-equal numbers as "equal" just because they 
happen to be "close".


The problem is that there is *no one right answer*, except "have everyone 
become an expert in floating point, then judge every case on its merits", 
which will never happen.

But if nothing else, I wish that we can get past the rank superstition 
that you should "never" test floats for equality. That would be a step 
forward.



-- 
Steven


From rosuav at gmail.com  Wed May 29 23:45:13 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 13:45:13 +1000
Subject: Short-circuit Logic
In-Reply-To: <51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmq6nvEV07pO0mZ28n_X7y-=RbtL+=6-F0_4s4yE8rAkLQ@mail.gmail.com>

On Thu, May 30, 2013 at 12:28 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> * de facto exact equality testing, only slower and with the *illusion* of
> avoiding equality, e.g. "abs(x-y) < sys.float_info.epsilon" is just a
> long and slow way of saying "x == y" when both numbers are sufficiently
> large;
>

The problem here, I think, is that "epsilon" has two meanings:

* sys.float_info.epsilon, which is an extremely specific value (the
smallest x such that 1.0+x != x)

* the mathematical concept, which is where the other got its name from.

Let's suppose someone is told to compare floating point numbers by
seeing if the absolute value of the difference is less than some
epsilon. They look up "absolute value" and find abs(); they look up
"epsilon" and think they've found it. Trouble is, they've found the
wrong epsilon... and really, there's an engineering issue here too.
Here's one of my favourite examples of equality comparisons:

http://xkcd.com/1047/

# Let's say we measured this accurately to one part in 40
x = one_light_year_in_meters

y = pow(99,8)
x == y  # False
abs(x-y) < x/40  # True

Measurement accuracy is usually far FAR worse than floating-point
accuracy. It's pretty pointless to compare for some kind of "equality"
that ignores this. Say you measure the diameter and circumference of a
circle, accurate to one meter, and got values of 79 and 248; does this
mean that pi is less than 3.14? No - in fact:

pi = 248/79
# math.pi = 3.141592653589793
abs(pi-math.pi) < pi/79  # True

Worst error is 1 in 79, so all comparisons are done with epsilon
derived from that.

ChrisA


From steve+comp.lang.python at pearwood.info  Thu May 30 01:42:17 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 05:42:17 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
Message-ID: <51a6e6b8$0$11118$c3e8da3@news.astraweb.com>

On Thu, 30 May 2013 13:45:13 +1000, Chris Angelico wrote:

> Let's suppose someone is told to compare floating point numbers by
> seeing if the absolute value of the difference is less than some
> epsilon. 

Which is usually the wrong way to do it! Normally one would prefer 
*relative* error, not absolute:

# absolute error:
abs(a - b) < epsilon


# relative error:
abs(a - b)/a < epsilon


One problem with absolute error is that it can give an entirely spurious 
image of "fuzziness", when in reality it is actually performing the same 
exact equality as == only slower and more verbosely. If a and b are 
sufficiently large, the smallest possible difference between a and b may 
be greater than epsilon (for whichever epsilon you pick). When that 
happens, you might as well just use == and be done with it.

But using relative error also raises questions:

- what if a is negative?

- why relative to a instead of relative to b?

- what if a is zero?

The first, at least, is easy to solve: take the absolute value of a. But 
strangely, you rarely see programming books mention that, so I expect 
that there is a lot of code in the real world that assumes a is positive 
and does the wrong thing when it isn't.

Here's another way, mathematically equivalent (although not necessarily 
equivalent using floating point computations!) which avoids the divide-by-
zero problem:

abs(a - b) < epsilon*a


Whichever method you choose, there are gotchas to watch out for.

> http://xkcd.com/1047/

Nice!


-- 
Steven


From jpiitula at ling.helsinki.fi  Thu May 30 03:22:02 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 30 May 2013 10:22:02 +0300
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
Message-ID: <qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>

Steven D'Aprano writes:

> On Thu, 30 May 2013 13:45:13 +1000, Chris Angelico wrote:
> 
> > Let's suppose someone is told to compare floating point numbers by
> > seeing if the absolute value of the difference is less than some
> > epsilon.
> 
> Which is usually the wrong way to do it! Normally one would prefer
> *relative* error, not absolute:
> 
> # absolute error:
> abs(a - b) < epsilon
> 
> 
> # relative error:
> abs(a - b)/a < epsilon
> 

...

I wonder why floating-point errors are not routinely discussed in
terms of ulps (units in last position). There is a recipe for
calculating the difference of two floating point numbers in ulps, and
it's possible to find the previous or next floating point number, but
I don't know of any programming language having built-in support for
these.

Why isn't this considered the most natural measure of a floating point
result being close to a given value? The meaning is roughly this: how
many floating point numbers there are between these two.

"close enough" if abs(ulps(a, b)) < 3 else "not close enough"

"equal" if ulps(a, b) == 0 else "not equal"

There must be some subtle technical issues here, too, but it puzzles
me that this measure of closeness is not often even discussed when
absolute and relative error are discussed - and computed using the
same approximate arithmetic whose accuracy is being measured. Scary.

Got light?


From steve+comp.lang.python at pearwood.info  Thu May 30 04:29:41 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 08:29:41 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>
Message-ID: <51a70df4$0$11118$c3e8da3@news.astraweb.com>

On Thu, 30 May 2013 10:22:02 +0300, Jussi Piitulainen wrote:

> I wonder why floating-point errors are not routinely discussed in terms
> of ulps (units in last position). There is a recipe for calculating the
> difference of two floating point numbers in ulps, and it's possible to
> find the previous or next floating point number, but I don't know of any
> programming language having built-in support for these.

That is an excellent question!

I think it is because the traditional recipes for "close enough" equality 
either pre-date any standardization of floating point types, or because 
they're written by people who are thinking about abstract floating point 
numbers and not considering the implementation.

Prior to most compiler and hardware manufacturers standardizing on IEEE 
754, there was no real way to treat float's implementation  in a machine 
independent way. Every machine laid their floats out differently, or used 
different number of bits. Some even used decimal, and in the case of a 
couple of Russian machines, trinary. (Although that's going a fair way 
back.)

But we now have IEEE 754, and C has conquered the universe, so it's 
reasonable for programming languages to offer an interface for accessing 
floating point objects in terms of ULPs. Especially for a language like 
Python, which only has a single float type.

I have a module that works with ULPs. I may clean it up and publish it. 
Would there be interest in seeing it in the standard library?


> Why isn't this considered the most natural measure of a floating point
> result being close to a given value? The meaning is roughly this: how
> many floating point numbers there are between these two.

There are some subtleties here also. Firstly, how many ULP should you 
care about? Three, as you suggest below, is awfully small, and chances 
are most practical, real-world calculations could not justify 3 ULP. 
Numbers that we normally care about, like "0.01mm", probably can justify 
thousands of ULP when it comes to C-doubles, which Python floats are.

Another subtlety: small-but-positive numbers are millions of ULP away 
from small-but-negative numbers. Also, there are issues to do with +0.0 
and -0.0, NANs and the INFs.


-- 
Steven


From jpiitula at ling.helsinki.fi  Thu May 30 05:07:40 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 30 May 2013 12:07:40 +0300
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>
	<51a70df4$0$11118$c3e8da3@news.astraweb.com>
Message-ID: <qotbo7sygwz.fsf@ruuvi.it.helsinki.fi>

Steven D'Aprano writes:

> On Thu, 30 May 2013 10:22:02 +0300, Jussi Piitulainen wrote:
> 
> > I wonder why floating-point errors are not routinely discussed in
> > terms of ulps (units in last position). There is a recipe for
> > calculating the difference of two floating point numbers in ulps,
> > and it's possible to find the previous or next floating point
> > number, but I don't know of any programming language having
> > built-in support for these.

...

> But we now have IEEE 754, and C has conquered the universe, so it's
> reasonable for programming languages to offer an interface for
> accessing floating point objects in terms of ULPs. Especially for a
> language like Python, which only has a single float type.

Yes, that's what I'm thinking, that there is now a ubiquitous floating
point format or two, so the properties of the format could be used.

> I have a module that works with ULPs. I may clean it up and publish it. 
> Would there be interest in seeing it in the standard library?

Yes, please.

> There are some subtleties here also. Firstly, how many ULP should
> you care about? Three, as you suggest below, is awfully small, and
> chances are most practical, real-world calculations could not
> justify 3 ULP.  Numbers that we normally care about, like "0.01mm",
> probably can justify thousands of ULP when it comes to C-doubles,
> which Python floats are.

I suppose this depends on the complexity of the process and the amount
of data that produced the numbers of interest. Many individual
floating point operations are required to be within an ulp or two of
the mathematically correct result, I think, and the rounding error
when parsing a written representation of a number should be similar.
Either these add up to produce large errors, or the computation is
approximate in other ways in addition to using floating point.

One could develop a kind of sense for such differences. Ulps could be
a tangible measure when comparing different algorithms. (That's what I
tried to do with them in the first place. And that's how I began to
notice their absence when floating point errors are discussed.)

> Another subtlety: small-but-positive numbers are millions of ULP
> away from small-but-negative numbers. Also, there are issues to do
> with +0.0 and -0.0, NANs and the INFs.

The usual suspects ^_^ and no reason to dismiss the ulp when the
competing kinds of error have their corresponding subtleties. A matter
of education, I'd say.

Thank you much for an illuminating discussion.


From nobody at nowhere.com  Thu May 30 18:55:25 2013
From: nobody at nowhere.com (Nobody)
Date: Thu, 30 May 2013 23:55:25 +0100
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>
	<51a70df4$0$11118$c3e8da3@news.astraweb.com>
	<qotbo7sygwz.fsf@ruuvi.it.helsinki.fi>
Message-ID: <pan.2013.05.30.22.55.17.876000@nowhere.com>

On Thu, 30 May 2013 12:07:40 +0300, Jussi Piitulainen wrote:

> I suppose this depends on the complexity of the process and the amount
> of data that produced the numbers of interest. Many individual
> floating point operations are required to be within an ulp or two of
> the mathematically correct result, I think, and the rounding error
> when parsing a written representation of a number should be similar.

Elementary operations (+, -, *, /, %, sqrt) are supposed to be within
+/- 0.5 ULP (for round-to-nearest), i.e. the actual result should be the
closest representable value to the exact result.

Transcendental functions should ideally be within +/- 1 ULP, i.e. the
actual result should be one of the two closest representable values to the
exact result. Determining the closest value isn't always feasible due to
the "table-maker's dilemma", i.e. the fact that regardless of the number
of digits used for intermediate results, the upper and lower bounds
can remain on opposite sides of the dividing line.



From stefan at drees.name  Fri May 31 11:34:36 2013
From: stefan at drees.name (Stefan Drees)
Date: Fri, 31 May 2013 17:34:36 +0200
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>
	<51a70df4$0$11118$c3e8da3@news.astraweb.com>
Message-ID: <koafuc$jdp$1@online.de>

On 2013-05-30 08:29:41 +0000, Steven D'Aprano said:
> On Thu, 30 May 2013 10:22:02 +0300, Jussi Piitulainen wrote:
>> I wonder why floating-point errors are not routinely discussed in terms
>> of ulps (units in last position). ...
> That is an excellent question! ...
> I have a module that works with ULPs. I may clean it up and publish it.
> Would there be interest in seeing it in the standard library? ...

I am definitely interested seeing this in the python standard library.
But as I continued to read the lines following your proposal and the 
excellent article from Bruce pointed to by Carlos on this thread, maybe 
a package on pypi first grounding somewhat the presumably massive 
discussion thread on python-ideas :-?)

All the best,

Stefan.




From roy at panix.com  Thu May 30 08:48:59 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 30 May 2013 08:48:59 -0400
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>
Message-ID: <roy-DD696C.08485830052013@news.panix.com>

In article <qotk3mhx78l.fsf at ruuvi.it.helsinki.fi>,
 Jussi Piitulainen <jpiitula at ling.helsinki.fi> wrote:

> I wonder why floating-point errors are not routinely discussed in
> terms of ulps (units in last position).

Analysis of error is a complicated topic (and is much older than digital 
computers).  These sorts of things come up in the real world, too.  For 
example, let's say I have two stakes driven into the ground 1000 feet 
apart.  One of them is near me and is my measurement datum.

I want to drive a third stake which is 1001 feet away from the datum.  
Do I measure 1 foot from the second stake, or do I take out my 
super-long tape measure and measure 1001 feet from the datum?


From carlosnepomuceno at outlook.com  Thu May 30 20:03:08 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 31 May 2013 03:03:08 +0300
Subject: Short-circuit Logic
In-Reply-To: <4dofq8pjvfbtjlkvks4lolsnltktvbuvf5@invalid.netcom.com>
References: <51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>,
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>,
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>,
	<mailman.2365.1369847746.3114.python-list@python.org>,
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.2392.1369885517.3114.python-list@python.org>,
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>,
	<qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>,
	<roy-DD696C.08485830052013@news.panix.com>,
	<4dofq8pjvfbtjlkvks4lolsnltktvbuvf5@invalid.netcom.com>
Message-ID: <BLU176-W409B0F8863BC79800C5117D7920@phx.gbl>

----------------------------------------
> To: python-list at python.org
> From: wlfraed at ix.netcom.com
> Subject: Re: Short-circuit Logic
> Date: Thu, 30 May 2013 19:38:31 -0400
>
> On Thu, 30 May 2013 08:48:59 -0400, Roy Smith <roy at panix.com> declaimed
> the following in gmane.comp.python.general:
>
>>
>> Analysis of error is a complicated topic (and is much older than digital
>> computers). These sorts of things come up in the real world, too. For
>> example, let's say I have two stakes driven into the ground 1000 feet
>> apart. One of them is near me and is my measurement datum.
>>
>> I want to drive a third stake which is 1001 feet away from the datum.
>> Do I measure 1 foot from the second stake, or do I take out my
>> super-long tape measure and measure 1001 feet from the datum?
>
> On the same azimuth? Using the "super long tape" and ensuring it
> traverses the 1000 foot stake is probably going to be most accurate --
> you only have the uncertainty of the positioning of the tape on the
> datum, and the small uncertainty of azimuth over the 1000 foot stake.
> And even the azimuth error isn't contributing to the distance error.
>
> Measuring 1 foot from the 1000 foot stake leaves you with any error
> from datum to the 1000 foot, plus any error from the 1000 foot, PLUS any
> azimuth error which would contribute to shortening the datum distance.

Just because you have more causes of error doesn't mean you have lesser accurate measures.

If fact, errors may compensate each other. It all depends on the bias (accuracy) and variation (precision) involved in the measurements you are considering.

> --
> Wulfraed Dennis Lee Bieber AF6VN
> wlfraed at ix.netcom.com HTTP://wlfraed.home.netcom.com/
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From nobody at nowhere.com  Thu May 30 21:10:03 2013
From: nobody at nowhere.com (Nobody)
Date: Fri, 31 May 2013 02:10:03 +0100
Subject: Short-circuit Logic
References: <51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>
	<roy-DD696C.08485830052013@news.panix.com>
	<mailman.2464.1369957122.3114.python-list@python.org>
Message-ID: <pan.2013.05.31.01.09.55.109000@nowhere.com>

On Thu, 30 May 2013 19:38:31 -0400, Dennis Lee Bieber wrote:

> 	Measuring 1 foot from the 1000 foot stake leaves you with any error
> from datum to the 1000 foot, plus any error from the 1000 foot, PLUS any
> azimuth error which would contribute to shortening the datum distance.

First, let's ignore azimuthal error.

If you measure both distances from the same origin, and you have a
measurement error of 0.1% (i.e. 1/1000), then the 1000' measurement will
actually be between 999' and 1001', while the 1001' measurement will be
between 1000' and 1002' (to the nearest whole foot).

Meaning that the distance from the 1000' stake to the 1001' stake could be
anywhere between -1' and 3' (i.e. the 1001' stake could be measured as
being closer than the 1000' stake).

This is why technical drawings which include regularly-spaced features
will normally specify the positions of features relative to their
neighbours instead of (or as well as) relative to some origin.

When you're dealing with relative error, the obvious question is
"relative to what?".



From roy at panix.com  Thu May 30 21:21:14 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 30 May 2013 21:21:14 -0400
Subject: Short-circuit Logic
References: <51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>
	<roy-DD696C.08485830052013@news.panix.com>
	<mailman.2464.1369957122.3114.python-list@python.org>
	<pan.2013.05.31.01.09.55.109000@nowhere.com>
Message-ID: <roy-9D5C42.21211430052013@news.panix.com>

In article <pan.2013.05.31.01.09.55.109000 at nowhere.com>,
 Nobody <nobody at nowhere.com> wrote:

> On Thu, 30 May 2013 19:38:31 -0400, Dennis Lee Bieber wrote:
> 
> > 	Measuring 1 foot from the 1000 foot stake leaves you with any error
> > from datum to the 1000 foot, plus any error from the 1000 foot, PLUS any
> > azimuth error which would contribute to shortening the datum distance.
> 
> First, let's ignore azimuthal error.
> 
> If you measure both distances from the same origin, and you have a
> measurement error of 0.1% (i.e. 1/1000), then the 1000' measurement will
> actually be between 999' and 1001', while the 1001' measurement will be
> between 1000' and 1002' (to the nearest whole foot).
> 
> Meaning that the distance from the 1000' stake to the 1001' stake could be
> anywhere between -1' and 3' (i.e. the 1001' stake could be measured as
> being closer than the 1000' stake).
> 
> This is why technical drawings which include regularly-spaced features
> will normally specify the positions of features relative to their
> neighbours instead of (or as well as) relative to some origin.

Not to mention "Do not scale drawing" warnings.  Do they still put that 
on drawings?  It was standard practice back when I was learning drafting.

> When you're dealing with relative error, the obvious question is
> "relative to what?".

Exactly.  Most programmers are very poorly training in these sorts of 
things (not to mention crypto, UX, etc).  I put myself in that camp too.  
I know just enough about floating point to understand that I don't 
really know what I'm doing.  I would never write a program where 
numerical accuracy was critical (say, stress analysis of a new airframe 
or a nuclear power plant control system) without having somebody who 
really knew that stuff on the team.


From torriem at gmail.com  Thu May 30 23:33:10 2013
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 30 May 2013 21:33:10 -0600
Subject: Short-circuit Logic
In-Reply-To: <pan.2013.05.31.01.09.55.109000@nowhere.com>
References: <51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<qotk3mhx78l.fsf@ruuvi.it.helsinki.fi>
	<roy-DD696C.08485830052013@news.panix.com>
	<mailman.2464.1369957122.3114.python-list@python.org>
	<pan.2013.05.31.01.09.55.109000@nowhere.com>
Message-ID: <51A819F6.3050605@gmail.com>

On 05/30/2013 07:10 PM, Nobody wrote:
> This is why technical drawings which include regularly-spaced features
> will normally specify the positions of features relative to their
> neighbours instead of (or as well as) relative to some origin.

If I am planting trees, putting in fence posts, or drilling lots of
little holes in steel, I am actually more likely to measure from the
origin (or one arbitrary position).  I trust that the errors
accumulating as the tape measure marks were printed on the tape is less
than the error I'd accumulate by digging a hole, and measuring from
there to the next hole.  And definitely when drilling a series of holes
I'll never measure hole to hole to mark.  If I measure from the origin
than any error for the hole is limited to itself as much as possible
rather than passing on the error to subsequent hole positions.  If I was
making a server rack, for example, having the holes consistently near
their desired position is necessary.  Tolerances are such that my hole
can be off by as much as a 1/16" of inch of my desired position and it
would still be fine, but not if each hole was off by an additional
1/16".  I guess what I've described is accuracy vs precision.  In the
case of the server rack accuracy is important, and precision can be more
coarse depending on the screw size and the mount type (threaded hole vs
square hole with snap-in nut).


From rosuav at gmail.com  Thu May 30 04:29:23 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 18:29:23 +1000
Subject: Short-circuit Logic
In-Reply-To: <51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
Message-ID: <CAPTjJmqMjv1NUiWpy6LF1mObE7OXXWd-uybBsnfZ1U-3OcNC0A@mail.gmail.com>

On Thu, May 30, 2013 at 3:42 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Thu, 30 May 2013 13:45:13 +1000, Chris Angelico wrote:
>
>> Let's suppose someone is told to compare floating point numbers by
>> seeing if the absolute value of the difference is less than some
>> epsilon.
>
> Which is usually the wrong way to do it! Normally one would prefer
> *relative* error, not absolute:
>
> # absolute error:
> abs(a - b) < epsilon
>
>
> # relative error:
> abs(a - b)/a < epsilon

I was picking an epsilon based on a, though, which comes to pretty
much the same thing as the relative error calculation you're using.

> But using relative error also raises questions:
>
> - what if a is negative?
>
> - why relative to a instead of relative to b?
>
> - what if a is zero?
>
> The first, at least, is easy to solve: take the absolute value of a.

One technique I saw somewhere is to use the average of a and b. But
probably better is to take the lower absolute value (ie the larger
epsilon). However, there's still the question of what epsilon should
be - what percentage of a or b you take to mean equal - and that one
is best answered by looking at the original inputs.

Take these guys, for instance. Doing the same thing I was, only with
more accuracy.

http://www.youtube.com/watch?v=ZNiRzZ66YN0

ChrisA


From carlosnepomuceno at outlook.com  Thu May 30 17:03:13 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 31 May 2013 00:03:13 +0300
Subject: Short-circuit Logic
In-Reply-To: <51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>,
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>,
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>,
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>,
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>,
	<mailman.2365.1369847746.3114.python-list@python.org>,
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.2392.1369885517.3114.python-list@python.org>,
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
Message-ID: <BLU176-W45076512CD28A83230E3CD7910@phx.gbl>

----------------------------------------
> From: steve+comp.lang.python at pearwood.info
> Subject: Re: Short-circuit Logic
> Date: Thu, 30 May 2013 05:42:17 +0000
> To: python-list at python.org
[...]
> Here's another way, mathematically equivalent (although not necessarily
> equivalent using floating point computations!) which avoids the divide-by-
> zero problem:
>
> abs(a - b) < epsilon*a

That's wrong! If abs(a) < abs(a-b)/epsilon you will break the commutative law. For example:

import sys
eps = sys.float_info.epsilon
def almost_equalSD(a,b):
??? return abs(a-b) < eps*a

#special case
a=1
b=1/(1-eps)
almost_equalSD(a,b) == almost_equalSD(b,a)

Returns False.

This discussion reminded me of TAOCP and I paid a visit and bring the following functions:


#Floating Point Comparison Operations
#Knuth, Donald (1981). The Art of Computer Programming. 2nd ed. Vol. 2. p. 218. Addison-Wesley. ISBN 0-201-03822-6.
import sys

#floating point comparison: u ? v(?) "definitely less than" (definition 21)
def fpc_dlt(u,v,eps=sys.float_info.epsilon):
??? au=abs(u)
??? av=abs(v)
??? return (v-u)> (eps*(au if au>av else av))? # v-u> ?*max(|u|,|v|)

#floating point comparison: u ~ v(?) "approximately equal to" (definition 22)
def fpc_aeq(u,v,eps=sys.float_info.epsilon):
??? au=abs(u)
??? av=abs(v)
??? return abs(v-u) <= (eps*(au if au>av else av))? # |v-u| <= ?*max(|u|,|v|)

#floating point comparison: u ? v(?) "definitely greater than" (definition 23)
def fpc_dgt(u,v,eps=sys.float_info.epsilon):
??? au=abs(u)
??? av=abs(v)
??? return (u-v)> (eps*(au if au>av else av))? # u-v> ?*max(|u|,|v|)

#floating point comparison: u ? v(?) "essentially equal to" (definition 24)
def fpc_eeq(u,v,eps=sys.float_info.epsilon):
??? au=abs(u)
??? av=abs(v)
??? return abs(v-u) <= (eps*(au if au<av else av))? # |v-u| <= ?*min(|u|,|v|)


I've tried to make it look a bit pythonic. Please let me know if it can be improved. ;)

So, if you try the following you get the correct answer:

#special case
a=1
b=1/(1-eps)
fpc_aeq(a,b) == fpc_aeq(b,a)


>
> Whichever method you choose, there are gotchas to watch out for.
>
>> http://xkcd.com/1047/
>
> Nice!
>
>
> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From oscar.j.benjamin at gmail.com  Thu May 30 18:57:28 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 30 May 2013 23:57:28 +0100
Subject: Short-circuit Logic
In-Reply-To: <BLU176-W45076512CD28A83230E3CD7910@phx.gbl>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<BLU176-W45076512CD28A83230E3CD7910@phx.gbl>
Message-ID: <CAHVvXxTPwCCYGR8w3cbE4sKBsfYgTkcOWa5i4M5FvwXb6B0qGg@mail.gmail.com>

On 30 May 2013 22:03, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
>> Here's another way, mathematically equivalent (although not necessarily
>> equivalent using floating point computations!) which avoids the divide-by-
>> zero problem:
>>
>> abs(a - b) < epsilon*a
>
> That's wrong! If abs(a) < abs(a-b)/epsilon you will break the commutative law.

There is no commutative law for relative tolerance floating point
comparisons. If you want to compare with a relative tolerance then you
you should choose carefully what your tolerance is to be relative to
(and how big your relative tolerance should be).

In some applications it's obvious which of a or b you should use to
scale the tolerance but in others it is not or you should compare with
something more complex. For an example where it is obvious, when
testing numerical code I might write something like:

eps = 1e-7
true_answer = 123.4567879
estimate = myfunc(5)
assert abs(estimate - true_answer) < eps * abs(true_answer)


Oscar


From carlosnepomuceno at outlook.com  Thu May 30 19:06:09 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 31 May 2013 02:06:09 +0300
Subject: Short-circuit Logic
In-Reply-To: <CAHVvXxTPwCCYGR8w3cbE4sKBsfYgTkcOWa5i4M5FvwXb6B0qGg@mail.gmail.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>,
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>,
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>,
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>,
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>,
	<BLU176-W45076512CD28A83230E3CD7910@phx.gbl>,
	<CAHVvXxTPwCCYGR8w3cbE4sKBsfYgTkcOWa5i4M5FvwXb6B0qGg@mail.gmail.com>
Message-ID: <BLU176-W240AAF0EEDD0A7F3F9C1C2D7910@phx.gbl>

----------------------------------------
> From: oscar.j.benjamin at gmail.com
> Date: Thu, 30 May 2013 23:57:28 +0100
> Subject: Re: Short-circuit Logic
> To: carlosnepomuceno at outlook.com
> CC: python-list at python.org
>
> On 30 May 2013 22:03, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
>>> Here's another way, mathematically equivalent (although not necessarily
>>> equivalent using floating point computations!) which avoids the divide-by-
>>> zero problem:
>>>
>>> abs(a - b) < epsilon*a
>>
>> That's wrong! If abs(a) < abs(a-b)/epsilon you will break the commutative law.
>
> There is no commutative law for relative tolerance floating point
> comparisons. If you want to compare with a relative tolerance then you
> you should choose carefully what your tolerance is to be relative to
> (and how big your relative tolerance should be).

Off course there is! It might not suite your specific needs though.

I'll just quote Knuth because it's pretty damn good:

"A. An axiomatic approach. Although the associative law is not valid, the commutative law

u (+) v == v (+) u???? (2)

does hold, and this law can be a valuable conceptual asset in programming and in the analysis of programs. This example suggests that we should look for
important laws that are satified by (+), (-), (*), and (/); it is not unreasonable to say that floating point routines should be designed to preserve as many of the ordinary mathematical laws as possible. If more axioms are valid, it becomes easier to write good programs, and programs also become more portable from
machine to machine."
TAOCP, Vol .2, p. 214


> In some applications it's obvious which of a or b you should use to
> scale the tolerance but in others it is not or you should compare with
> something more complex. For an example where it is obvious, when
> testing numerical code I might write something like:
>
> eps = 1e-7
> true_answer = 123.4567879
> estimate = myfunc(5)
> assert abs(estimate - true_answer) < eps * abs(true_answer)
>
>
> Oscar 		 	   		  

From steve+comp.lang.python at pearwood.info  Fri May 31 01:13:51 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 31 May 2013 05:13:51 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2452.1369947802.3114.python-list@python.org>
Message-ID: <51a8318e$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Fri, 31 May 2013 00:03:13 +0300, Carlos Nepomuceno wrote:

> ----------------------------------------
>> From: steve+comp.lang.python at pearwood.info Subject: Re: Short-circuit
>> Logic
>> Date: Thu, 30 May 2013 05:42:17 +0000 To: python-list at python.org
> [...]
>> Here's another way, mathematically equivalent (although not necessarily
>> equivalent using floating point computations!) which avoids the
>> divide-by- zero problem:
>>
>> abs(a - b) < epsilon*a
> 
> That's wrong! If abs(a) < abs(a-b)/epsilon you will break the
> commutative law. For example:

What makes you think that the commutative law is relevant here?

Many things break the commutative law, starting with division and 
subtraction:

    20 - 10 != 10 - 20

    1/2 != 2/1

Most comparison operators other than equality and inequality:

    (23 < 42) != (42 < 23)

String concatenation:

    "Hello" + "World" != "World" + "Hello"

Many operations in the real world:

    put on socks, then shoes != put on shoes, then socks.


But you are correct that approximately-equal using *relative* error is 
not commutative. (Absolute error, on the other hand, is commutative.) As 
I said, any form of "approximate equality" has gotchas. But this gotcha 
is simple to overcome: 

    abs(a -b) < eps*max(abs(a), abs(b))

(Knuth's "approximately equal to" which you give.)


> This discussion reminded me of TAOCP and I paid a visit and bring the
> following functions:

"TAOCP"?


-- 
Steven


From carlosnepomuceno at outlook.com  Fri May 31 02:42:38 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 31 May 2013 09:42:38 +0300
Subject: Short-circuit Logic
In-Reply-To: <51a8318e$0$29966$c3e8da3$5496439d@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>,
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>,
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>,
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>,
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>,
	<mailman.2365.1369847746.3114.python-list@python.org>,
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>,
	<mailman.2392.1369885517.3114.python-list@python.org>,
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>,
	<mailman.2452.1369947802.3114.python-list@python.org>,
	<51a8318e$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <BLU176-W28A61653403AEE96A39A0D7920@phx.gbl>

----------------------------------------
> From: steve+comp.lang.python at pearwood.info
> Subject: Re: Short-circuit Logic
> Date: Fri, 31 May 2013 05:13:51 +0000
> To: python-list at python.org
>
> On Fri, 31 May 2013 00:03:13 +0300, Carlos Nepomuceno wrote:
>
>> ----------------------------------------
>>> From: steve+comp.lang.python at pearwood.info Subject: Re: Short-circuit
>>> Logic
>>> Date: Thu, 30 May 2013 05:42:17 +0000 To: python-list at python.org
>> [...]
>>> Here's another way, mathematically equivalent (although not necessarily
>>> equivalent using floating point computations!) which avoids the
>>> divide-by- zero problem:
>>>
>>> abs(a - b) < epsilon*a
>>
>> That's wrong! If abs(a) < abs(a-b)/epsilon you will break the
>> commutative law. For example:
>
> What makes you think that the commutative law is relevant here?

How can't you see?

I'll requote a previous message:

}On Thu, 30 May 2013 13:45:13 +1000, Chris Angelico wrote:
} 
}> Let's suppose someone is told to compare floating point numbers by
}> seeing if the absolute value of the difference is less than some
}> epsilon. 
} 
}Which is usually the wrong way to do it! Normally one would prefer 
}*relative* error, not absolute:
?
Since we are considering Chris's supposition ("to compare floating point numbers") it's totally relevant to understand how that operation can be correctly implemented.


> Many things break the commutative law, starting with division and
> subtraction:
>
> 20 - 10 != 10 - 20
>
> 1/2 != 2/1
>
> Most comparison operators other than equality and inequality:
>
> (23 < 42) != (42 < 23)
>
> String concatenation:
>
> "Hello" + "World" != "World" + "Hello"
>
> Many operations in the real world:
>
> put on socks, then shoes != put on shoes, then socks.
>

That's is totally irrelevant in this case. The commutative law is essential to the equality operation.

> But you are correct that approximately-equal using *relative* error is
> not commutative. (Absolute error, on the other hand, is commutative.) As
> I said, any form of "approximate equality" has gotchas. But this gotcha
> is simple to overcome:
>
> abs(a -b) < eps*max(abs(a), abs(b))
>
> (Knuth's "approximately equal to" which you give.)
>
>
>> This discussion reminded me of TAOCP and I paid a visit and bring the
>> following functions:
>
> "TAOCP"?

The Art of Computer Programming[1]! An old book full of excellent stuff! A MUST READ!!!! ;)

http://www-cs-faculty.stanford.edu/~uno/taocp.html

[1] Knuth, Donald (1981). The Art of Computer Programming. 2nd ed. Vol. 2. p. 218. Addison-Wesley. ISBN 0-201-03822-6.

>
>
> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rosuav at gmail.com  Fri May 31 03:09:01 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 17:09:01 +1000
Subject: Short-circuit Logic
In-Reply-To: <51a8318e$0$29966$c3e8da3$5496439d@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2452.1369947802.3114.python-list@python.org>
	<51a8318e$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmo=ea-KAnc-X4DkMVrxEYUkPOBH-KWgGU+Kg0Eud1p7Mg@mail.gmail.com>

On Fri, May 31, 2013 at 3:13 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> What makes you think that the commutative law is relevant here?
>

Equality should be commutative. If a == b, then b == a. Also, it's
generally understood that if a == c and b == c, then a == b, though
there are more exceptions to that (especially in loosely-typed
languages).

ChrisA


From steve+comp.lang.python at pearwood.info  Fri May 31 04:11:30 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 31 May 2013 08:11:30 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2452.1369947802.3114.python-list@python.org>
	<51a8318e$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2473.1369982567.3114.python-list@python.org>
Message-ID: <51a85b31$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Fri, 31 May 2013 09:42:38 +0300, Carlos Nepomuceno wrote:

>> From: steve+comp.lang.python at pearwood.info Subject: Re: Short-circuit
>> Logic
>> Date: Fri, 31 May 2013 05:13:51 +0000 To: python-list at python.org
>>
>> On Fri, 31 May 2013 00:03:13 +0300, Carlos Nepomuceno wrote:
>>>> From: steve+comp.lang.python at pearwood.info Subject: Re: Short-circuit
>>>> Logic
>>>> Date: Thu, 30 May 2013 05:42:17 +0000 To: python-list at python.org
>>> [...]
>>>> Here's another way, mathematically equivalent (although not
>>>> necessarily equivalent using floating point computations!) which
>>>> avoids the divide-by- zero problem:
>>>>
>>>> abs(a - b) < epsilon*a
>>>
>>> That's wrong! If abs(a) < abs(a-b)/epsilon you will break the
>>> commutative law. For example:
>>
>> What makes you think that the commutative law is relevant here?
> 
> How can't you see?

I can ask the same thing about you. How can you see that it is not 
relevant?


> I'll requote a previous message:

Thanks, but that's entirely irrelevant. It says nothing about the 
commutative law.

[...]
> Since we are considering Chris's supposition ("to compare floating point
> numbers") it's totally relevant to understand how that operation can be
> correctly implemented.

Of course! But what does that have to do with the commutative law?


>> Many things break the commutative law, starting with division and
>> subtraction:
>>
>> 20 - 10 != 10 - 20
>>
>> 1/2 != 2/1
>>
>> Most comparison operators other than equality and inequality:
>>
>> (23 < 42) != (42 < 23)
[...]
> That's is totally irrelevant in this case. The commutative law is
> essential to the equality operation.

That's fine, but we're not talking about equality, we're talking about 
*approximately equality* or *almost equal*. Given the simple definition 
of relative error under discussion, the commutative law does not hold. 
The mere fact that it does not hold is no big deal. It doesn't hold for 
many comparison operators.

Nor does the transitive law hold, even using absolute epsilon:

eps = 0.5
a = 1.1
b = 1.5
c = 1.9

then a ? b, and b ? c, but a ? c.


-- 
Steven


From steve+comp.lang.python at pearwood.info  Fri May 31 04:45:13 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 31 May 2013 08:45:13 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2452.1369947802.3114.python-list@python.org>
	<51a8318e$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2474.1369984150.3114.python-list@python.org>
Message-ID: <51a86319$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Fri, 31 May 2013 17:09:01 +1000, Chris Angelico wrote:

> On Fri, May 31, 2013 at 3:13 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> What makes you think that the commutative law is relevant here?
>>
>>
> Equality should be commutative. If a == b, then b == a. Also, it's
> generally understood that if a == c and b == c, then a == b, though
> there are more exceptions to that (especially in loosely-typed
> languages).

Who is talking about equality? Did I just pass through the Looking Glass 
into Wonderland again? *wink*

We're talking about *approximate equality*, which is not the same thing, 
despite the presence of the word "equality" in it. It is non-commutative, 
just like other comparisons like "less than" and "greater than or equal 
to". Nobody gets their knickers in a twist because the >= operator is non-
commutative.

Approximate equality is not just non-commutative, it's also intransitive. 
I'm reminded of a story about Ken Iverson, the creator of APL. Iverson 
was a strong proponent of what he called "tolerant equality", and APL 
defined the = operator as a relative approximate equal, rather than the 
more familiar exactly-equal operator most programming languages use.

    In an early talk Ken was explaining the advantages of tolerant
    comparison. A member of the audience asked incredulously, 
    ?Surely you don?t mean that when A=B and B=C, A may not equal C??
    Without skipping a beat, Ken replied, ?Any carpenter knows that!?
    and went on to the next question. ? Paul Berry

 
    The intransitivity of [tolerant] equality is well known in
    practical situations and can be easily demonstrated by sawing
    several pieces of wood of equal length. In one case, use the
    first piece to measure subsequent lengths; in the second case,
    use the last piece cut to measure the next. Compare the lengths
    of the two final pieces.
    ? Richard Lathwell, APL Comparison Tolerance, APL76, 1976 


See also here:

http://www.jsoftware.com/papers/APLEvol.htm

(search for "fuzz" or "tolerance".



-- 
Steven


From roy at panix.com  Fri May 31 09:20:02 2013
From: roy at panix.com (Roy Smith)
Date: Fri, 31 May 2013 09:20:02 -0400
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2392.1369885517.3114.python-list@python.org>
	<51a6e6b8$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2452.1369947802.3114.python-list@python.org>
	<51a8318e$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<mailman.2474.1369984150.3114.python-list@python.org>
	<51a86319$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-19C815.09200231052013@news.panix.com>

In article <51a86319$0$29966$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

>     In an early talk Ken was explaining the advantages of tolerant
>     comparison. A member of the audience asked incredulously, 
>     ???Surely you don???t mean that when A=B and B=C, A may not equal C????
>     Without skipping a beat, Ken replied, ???Any carpenter knows that!???
>     and went on to the next question. ??? Paul Berry

Any any good carpenter also knows it's better to copy than to measure.  
Let's say I have a door frame and I need to trim a door to fit it 
exactly.  I can do one of two things.

First, I could take out my tape measure and measure that the frame is 29 
and 11/32 inches wide.  Then, carry that tape measure to the door, 
measure off 29 and 11/32 inches, and make a mark.

Or, I could take a handy stick of wood which is 30-something inches 
long, lay it down at the bottom of the door frame with one end up snug 
against one side, and make a mark at the other side of the frame.  Then 
carry my stick to the door and keep trimming until it's the same width 
as the marked section on the stick.

Google for "story stick".

The tape measure is like digital floating point.  It introduces all 
sorts of ways for errors to creep in and people who care about getting 
doors to properly fit into door frames understand all that.


From dihedral88888 at gmail.com  Thu May 30 23:11:38 2013
From: dihedral88888 at gmail.com (88888 Dihedral)
Date: Thu, 30 May 2013 20:11:38 -0700 (PDT)
Subject: Short-circuit Logic
In-Reply-To: <51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<48519aa0-d0cd-4ffc-a2f5-2107465321d8@qn4g2000pbc.googlegroups.com>
	<mailman.2365.1369847746.3114.python-list@python.org>
	<51a6b969$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <987fed2a-e7c7-4bcc-8aaf-9608e21eff26@googlegroups.com>

Steven D'Aprano? 2013?5?30????UTC+8??10?28?57????
> On Wed, 29 May 2013 10:50:47 -0600, Ian Kelly wrote:
> 
> 
> 
> > On Wed, May 29, 2013 at 8:33 AM, rusi <rustompmody at gmail.com> wrote:
> 
> >> 0.0 == 0.0 implies 5.4 == 5.4
> 
> >> is not a true statement is what (I think) Steven is saying. 0 (or if
> 
> >> you prefer 0.0) is special and is treated specially.
> 
> > 
> 
> > It has nothing to do with 0 being special.  A floating point number will
> 
> > always equal itself (except for nan, which is even more special), and in
> 
> > particular 5.4 == 5.4.  But if you have two different calculations that
> 
> > produce 0, or two different calculations that produce 5.4, you might
> 
> > actually get two different numbers that approximate 0 or 5.4 thanks to
> 
> > rounding error.  If you then compare those two ever-so-slightly
> 
> > different numbers, you will find them unequal.
> 
> 
> 
> EXACTLY!
> 
> 
> 
> The problem does not lie with the *equality operator*, it lies with the 
> 
> calculations. And that is an intractable problem -- in general, floating 
> 
> point is *hard*. So the problem occurs when we start with a perfectly 
> 
> good statement of the facts:
> 
> 
> 
> "If you naively test the results of a calculation for equality without 
> 
> understanding what you are doing, you will often get surprising results"
> 
> 
> 
> which then turns into a general heuristic that is often, but not always, 
> 
> reasonable:
> 
> 
> 
> "In general, you should test for floating point *approximate* equality, 
> 
> in some appropriate sense, rather than exact equality"
> 
> 
> 
> which then gets mangled to:
> 
> 
> 
> "Never test floating point numbers for equality"
> 
> 
> 
> and then implemented badly by people who have no clue what they are doing 
> 
> and have misunderstood the nature of the problem, leading to either:
> 
> 
> 
> * de facto exact equality testing, only slower and with the *illusion* of 
> 
> avoiding equality, e.g. "abs(x-y) < sys.float_info.epsilon" is just a 
> 
> long and slow way of saying "x == y" when both numbers are sufficiently 
> 
> large;
> 
> 
> 
> * incorrectly accepting non-equal numbers as "equal" just because they 
> 
> happen to be "close".
> 
> 
> 
> 
> 
> The problem is that there is *no one right answer*, except "have everyone 
> 
> become an expert in floating point, then judge every case on its merits", 
> 
> which will never happen.
> 
> 
> 
> But if nothing else, I wish that we can get past the rank superstition 
> 
> that you should "never" test floats for equality. That would be a step 
> 
> forward.
> 
> 
> 
> 
> 
> 
> 
> -- 
> 
> Steven

The string used to represent a floating number
in a computer language is normally in the decimal base of very 
some limited digits.

Anyway with the advances of A/D-converters in the past 10 years
which are reflected in the anttena- transmitter parts in phones, 
the long integer part in Python can really beat the low cost 
32- 64 bit floating computations in scientific calculations.


From steve+comp.lang.python at pearwood.info  Thu May 30 01:10:49 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 05:10:49 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
Message-ID: <51a6df59$0$11118$c3e8da3@news.astraweb.com>

On Wed, 29 May 2013 07:27:40 -0700, Ahmed Abdulshafy wrote:

> On Tuesday, May 28, 2013 3:48:17 PM UTC+2, Steven D'Aprano wrote:
>> On Mon, 27 May 2013 13:11:28 -0700, Ahmed Abdulshafy wrote:
>> 
>> 
>> 
>> > That may be true for integers, but for floats, testing for equality
>> > is
>> 
>> > not always precise
>> 
>> 
>> 
>> Incorrect. Testing for equality is always precise, and exact. The
>> problem
>> 
>> is not the *equality test*, but that you don't always have the number
>> 
>> that you think you have. The problem lies elsewhere, not equality!
>> 
>> 
>> Steven
> 
> Well, this is taken from my python shell>
> 
>>>> 0.33455857352426283 == 0.33455857352426282
> True

This is an excellent example of misunderstanding what you are seeing. 
Both 0.33455857352426283 and 0.33455857352426282 represent the same 
float, so it is hardly a surprise that they compare equal -- they compare 
equal because they are equal.

py> a, b = 0.33455857352426283, 0.33455857352426282
py> a.as_integer_ratio()
(6026871468229899, 18014398509481984)
py> b.as_integer_ratio()
(6026871468229899, 18014398509481984)

You've made a common error: neglecting to take into account the finite 
precision of floats. Floats are not mathematical "real numbers", with 
infinite precision. The error is more obvious if we exaggerate it:

py> 0.3 == 0.300000000000000000000000000000000000000000000000000001
True

Most people who have seen an ordinary four-function calculator will 
realise that the issue here is *not* that the equality operator == is 
wrongly stating that two unequal numbers are equal, but that just because 
you enter 0.300...00001 doesn't mean that all those decimal places are 
actually used.


> Anyway, man, those were not my words anyway, most programming books I've
> read state so. Here's an excerpt from the Python book, I'm currently
> reading>
> 
> ">>> 0.0, 5.4, -2.5, 8.9e-4
> (0.0, 5.4000000000000004, -2.5, 0.00088999999999999995)
> 
> 
> The inexactness is not a problem specific to Python?all programming
> languages have this problem with floating-point numbers."

I'm not denying that floats are tricky to use correctly, or that testing 
for exact equality is *sometimes* the wrong thing to do:

# Wrong, don't do this!
x = 0.1
while x != 17.3:
    print(x)
    x += 0.1


I'm just saying that a simple minded comparison with 
sys.float_info.epsilon is *also* often wrong.


-- 
Steven


From rosuav at gmail.com  Thu May 30 01:22:23 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 15:22:23 +1000
Subject: Short-circuit Logic
In-Reply-To: <51a6df59$0$11118$c3e8da3@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
Message-ID: <CAPTjJmqfcdV2dSd4DWp=kh2rJNUD8bFbBjGPyn_nR97dz+uoiA@mail.gmail.com>

On Thu, May 30, 2013 at 3:10 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> # Wrong, don't do this!
> x = 0.1
> while x != 17.3:
>     print(x)
>     x += 0.1
>

Actually, I wouldn't do that with integers either. There are too many
ways that a subsequent edit could get it wrong and go infinite, so I'd
*always* use an inequality for that:

x = 1
while x < 173:
    print(x)
    x += 1

Well, in Python I'd use for/range, but the equivalent still applies. A
range() is still based on an inequality:

>>> list(range(1,6))
[1, 2, 3, 4, 5]
>>> list(range(1,6,3))
[1, 4]

Stops once it's no longer less than the end. That's safe, since Python
can't do integer wraparound.

ChrisA


From roy at panix.com  Thu May 30 08:40:16 2013
From: roy at panix.com (Roy Smith)
Date: Thu, 30 May 2013 08:40:16 -0400
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
Message-ID: <roy-B251F4.08401630052013@news.panix.com>

In article <mailman.2395.1369891346.3114.python-list at python.org>,
 Chris Angelico <rosuav at gmail.com> wrote:

> On Thu, May 30, 2013 at 3:10 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
> > # Wrong, don't do this!
> > x = 0.1
> > while x != 17.3:
> >     print(x)
> >     x += 0.1
> >
> 
> Actually, I wouldn't do that with integers either. There are too many
> ways that a subsequent edit could get it wrong and go infinite, so I'd
> *always* use an inequality for that:
> 
> x = 1
> while x < 173:
>     print(x)
>     x += 1

There's a big difference between these two.  In the first case, using 
less-than instead of testing for equality, you are protecting against 
known and expected floating point behavior.

In the second case, you're protecting against some vague, unknown, 
speculative future programming botch.  So, what *is* the right behavior 
if somebody were to accidentally drop three zeros into the source code:

> x = 1000
> while x < 173:
>     print(x)
>     x += 1

should the loop just quietly not execute (which is what it will do 
here)?  Will that make your program correct again, or will it simply 
turn this into a difficult to find bug?  If you're really worried about 
that, why not:

> x = 1
> while x != 173:
>     assert < 172
>     print(x)
>     x += 1


From rosuav at gmail.com  Thu May 30 08:58:27 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 22:58:27 +1000
Subject: Short-circuit Logic
In-Reply-To: <roy-B251F4.08401630052013@news.panix.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
Message-ID: <CAPTjJmoqjTyaoO0fiN13JNiFNstWSwzOVnS2YoXT7_OyaTxuFQ@mail.gmail.com>

On Thu, May 30, 2013 at 10:40 PM, Roy Smith <roy at panix.com> wrote:
> if somebody were to accidentally drop three zeros into the source code:
>
>> x = 1000
>> while x < 173:
>>     print(x)
>>     x += 1
>
> should the loop just quietly not execute (which is what it will do
> here)?  Will that make your program correct again, or will it simply
> turn this into a difficult to find bug?  If you're really worried about
> that, why not:

If you iterate from 1000 to 173, you get nowhere. This is the expected
behaviour; this is what a C-style for loop would be written as, it's
what range() does, it's the normal thing. Going from a particular
starting point to a particular ending point that's earlier than the
start results in no iterations. The alternative would be an infinite
number of iterations, which is far far worse.

ChrisA


From ethan at stoneleaf.us  Thu May 30 11:02:10 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Thu, 30 May 2013 08:02:10 -0700
Subject: Short-circuit Logic
In-Reply-To: <CAPTjJmoqjTyaoO0fiN13JNiFNstWSwzOVnS2YoXT7_OyaTxuFQ@mail.gmail.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<CAPTjJmoqjTyaoO0fiN13JNiFNstWSwzOVnS2YoXT7_OyaTxuFQ@mail.gmail.com>
Message-ID: <51A769F2.1050702@stoneleaf.us>

On 05/30/2013 05:58 AM, Chris Angelico wrote:
> On Thu, May 30, 2013 at 10:40 PM, Roy Smith <roy at panix.com> wrote:
>> if somebody were to accidentally drop three zeros into the source code:
>>
>>> x = 1000
>>> while x < 173:
>>>      print(x)
>>>      x += 1
>>
>> should the loop just quietly not execute (which is what it will do
>> here)?  Will that make your program correct again, or will it simply
>> turn this into a difficult to find bug?  If you're really worried about
>> that, why not:
>
> If you iterate from 1000 to 173, you get nowhere. This is the expected
> behaviour; this is what a C-style for loop would be written as, it's
> what range() does, it's the normal thing. Going from a particular
> starting point to a particular ending point that's earlier than the
> start results in no iterations. The alternative would be an infinite
> number of iterations, which is far far worse.

If the bug is the extra three zeros (maybe it should have been two), 
then silently skipping the loop is the "far, far worse" scenario.  With 
the infinite loop you at least know something went wrong, and you know 
it pretty darn quick (since you are testing, right? ;).

--
~Ethan~


From rosuav at gmail.com  Thu May 30 11:56:09 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 01:56:09 +1000
Subject: Short-circuit Logic
In-Reply-To: <51A769F2.1050702@stoneleaf.us>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<CAPTjJmoqjTyaoO0fiN13JNiFNstWSwzOVnS2YoXT7_OyaTxuFQ@mail.gmail.com>
	<51A769F2.1050702@stoneleaf.us>
Message-ID: <CAPTjJmoKPccw=ZpA_02m5HAwO1KtfLBQW-D-Lt-fuBzDCC0Qmw@mail.gmail.com>

On Fri, May 31, 2013 at 1:02 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
> On 05/30/2013 05:58 AM, Chris Angelico wrote:
>> If you iterate from 1000 to 173, you get nowhere. This is the expected
>> behaviour; this is what a C-style for loop would be written as, it's
>> what range() does, it's the normal thing. Going from a particular
>> starting point to a particular ending point that's earlier than the
>> start results in no iterations. The alternative would be an infinite
>> number of iterations, which is far far worse.
>
> If the bug is the extra three zeros (maybe it should have been two), then
> silently skipping the loop is the "far, far worse" scenario.  With the
> infinite loop you at least know something went wrong, and you know it pretty
> darn quick (since you are testing, right? ;).

You're assuming you can casually hit Ctrl-C to stop an infinite loop,
meaning that it's trivial. It's not. Not everything lets you do that;
or possibly halting the process will halt far more than you intended.
What if you're editing live code in something that's had uninterrupted
uptime for over a year? Doing nothing is much safer than getting stuck
in an infinite loop. And yes, I have done exactly that, though not in
Python. Don't forget, your start/stop figures mightn't be constants,
so you might not see it in testing. I can't imagine ANY scenario where
you'd actually *want* the infinite loop behaviour, while there are
plenty where you want it to skip the loop, and would otherwise have to
guard it with an if.

ChrisA


From ethan at stoneleaf.us  Thu May 30 12:30:11 2013
From: ethan at stoneleaf.us (Ethan Furman)
Date: Thu, 30 May 2013 09:30:11 -0700
Subject: Short-circuit Logic
In-Reply-To: <CAPTjJmoKPccw=ZpA_02m5HAwO1KtfLBQW-D-Lt-fuBzDCC0Qmw@mail.gmail.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<CAPTjJmoqjTyaoO0fiN13JNiFNstWSwzOVnS2YoXT7_OyaTxuFQ@mail.gmail.com>
	<51A769F2.1050702@stoneleaf.us>
	<CAPTjJmoKPccw=ZpA_02m5HAwO1KtfLBQW-D-Lt-fuBzDCC0Qmw@mail.gmail.com>
Message-ID: <51A77E93.9050909@stoneleaf.us>

On 05/30/2013 08:56 AM, Chris Angelico wrote:
> On Fri, May 31, 2013 at 1:02 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>> On 05/30/2013 05:58 AM, Chris Angelico wrote:
>>> If you iterate from 1000 to 173, you get nowhere. This is the expected
>>> behaviour; this is what a C-style for loop would be written as, it's
>>> what range() does, it's the normal thing. Going from a particular
>>> starting point to a particular ending point that's earlier than the
>>> start results in no iterations. The alternative would be an infinite
>>> number of iterations, which is far far worse.
>>
>> If the bug is the extra three zeros (maybe it should have been two), then
>> silently skipping the loop is the "far, far worse" scenario.  With the
>> infinite loop you at least know something went wrong, and you know it pretty
>> darn quick (since you are testing, right? ;).
>
> You're assuming you can casually hit Ctrl-C to stop an infinite loop,
> meaning that it's trivial. It's not. Not everything lets you do that;
> or possibly halting the process will halt far more than you intended.
> What if you're editing live code in something that's had uninterrupted
> uptime for over a year? Doing nothing is much safer than getting stuck
> in an infinite loop. And yes, I have done exactly that, though not in
> Python. Don't forget, your start/stop figures mightn't be constants,
> so you might not see it in testing. I can't imagine ANY scenario where
> you'd actually *want* the infinite loop behaviour, while there are
> plenty where you want it to skip the loop, and would otherwise have to
> guard it with an if.

We're not talking about skipping the loop on purpose, but on accident. 
Sure, taking a system down is no fun -- on the other hand, how much data 
corruption can occur before somebody realises there's a problem, and 
then how long to track it down to a silently, accidently, skipped loop?

--
~Ethan~


From steve+comp.lang.python at pearwood.info  Thu May 30 12:40:52 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 16:40:52 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<CAPTjJmoqjTyaoO0fiN13JNiFNstWSwzOVnS2YoXT7_OyaTxuFQ@mail.gmail.com>
	<51A769F2.1050702@stoneleaf.us>
	<mailman.2429.1369929372.3114.python-list@python.org>
Message-ID: <51a78113$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Fri, 31 May 2013 01:56:09 +1000, Chris Angelico wrote:

> On Fri, May 31, 2013 at 1:02 AM, Ethan Furman <ethan at stoneleaf.us>
> wrote:
>> On 05/30/2013 05:58 AM, Chris Angelico wrote:
>>> If you iterate from 1000 to 173, you get nowhere. This is the expected
>>> behaviour; this is what a C-style for loop would be written as, it's
>>> what range() does, it's the normal thing. Going from a particular
>>> starting point to a particular ending point that's earlier than the
>>> start results in no iterations. The alternative would be an infinite
>>> number of iterations, which is far far worse.
>>
>> If the bug is the extra three zeros (maybe it should have been two),
>> then silently skipping the loop is the "far, far worse" scenario.  With
>> the infinite loop you at least know something went wrong, and you know
>> it pretty darn quick (since you are testing, right? ;).
> 
> You're assuming you can casually hit Ctrl-C to stop an infinite loop,
> meaning that it's trivial. It's not. Not everything lets you do that; or
> possibly halting the process will halt far more than you intended. What
> if you're editing live code in something that's had uninterrupted uptime
> for over a year? 

Then more fool you for editing live code.

By the way, this is Python. Editing live code is not easy, if it's 
possible at all.

But even when possible, it's certainly not sensible. You don't insist on 
your car mechanic giving your car a grease and oil change while you're 
driving at 100kmh down the freeway, and you shouldn't insist that your 
developers modify your code while it runs.

In any case, your arguing about such abstract, hypothetical ideas that, 
frankly, *anything at all* might be said about it. "What if Ctrl-C causes 
some great disaster?" can be answered with an equally hypothetical "What 
if Ctrl-C prevents some great disaster?"


> Doing nothing is much safer than getting stuck in an
> infinite loop. 

I disagree. And I agree. It all depends on the circumstances. But, given 
that we are talking about Python where infinite loops can be trivially 
broken out of, *in my experience* they are less-worse than silently doing 
nothing.

I've occasionally written faulty code that enters an infinite loop. When 
that happens, it's normally pretty obvious: something which should 
complete in a millisecond is still running after ten minutes. That's a 
clear, obvious, *immediate* sign that I've screwed up, which leads to me 
fixing the problem.

On the other hand, I've occasionally written faulty code that does 
nothing at all. The specific incident I am thinking of, I wrote a bunch 
of doctests which *weren't being run at all*. For nearly two weeks (not 
full time, but elapsed time) I was developing this code, before I started 
to get suspicious that *none* of the tests had failed, not even once. I 
mean, I'm not that good a programmer. Eventually I put in some deliberate 
errors, and they still didn't fail. 

In actuality, nearly every test was failing, my entire code base was 
rubbish, and I just didn't know it.

So, in this specific case, I would have *much* preferred an obvious 
failure (such as an infinite loop) than code that silently does the wrong 
thing.

We've drifted far from the original topic. There is a distinct difference 
between guarding against inaccuracies in floating point calculations:

# Don't do this!
total = 0.0
while total != 1.0:
    total += 0.1

and guarding against typos in source code:

total = 90  # Oops, I meant 0
while total != 10:
    total += 1

The second case is avoidable by paying attention when you code. The first 
case is not easily avoidable, because it reflects a fundamental 
difficulty with floating point types.

As a general rule, "defensive coding" does not extend to the idea of 
defending against mistakes in your code. The compiler, linter or unit 
tests are supposed to do that. Occasionally, I will code defensively when 
initialising tedious data sets:

prefixes = ['y', 'z', 'a', 'f', 'p', 'n', '?', 'm', 
            'k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y']
assert len(prefixes) == 16


but that's about as far as I go.


-- 
Steven


From steve+comp.lang.python at pearwood.info  Thu May 30 15:22:46 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 19:22:46 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<CAPTjJmoqjTyaoO0fiN13JNiFNstWSwzOVnS2YoXT7_OyaTxuFQ@mail.gmail.com>
	<51A769F2.1050702@stoneleaf.us>
	<mailman.2429.1369929372.3114.python-list@python.org>
	<51a78113$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <51a7a706$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Thu, 30 May 2013 16:40:52 +0000, Steven D'Aprano wrote:

> On Fri, 31 May 2013 01:56:09 +1000, Chris Angelico wrote:

>> You're assuming you can casually hit Ctrl-C to stop an infinite loop,
>> meaning that it's trivial. It's not. Not everything lets you do that;
>> or possibly halting the process will halt far more than you intended.
>> What if you're editing live code in something that's had uninterrupted
>> uptime for over a year?
> 
> Then more fool you for editing live code.

Ouch! That came out much harsher than it sounded in my head :(

Sorry Chris, that wasn't intended as a personal attack against you, just 
as a comment on the general inadvisability of modifying code on the fly 
while it is being run.


-- 
Steven


From rosuav at gmail.com  Thu May 30 17:46:04 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 07:46:04 +1000
Subject: Short-circuit Logic
In-Reply-To: <51a7a706$0$29966$c3e8da3$5496439d@news.astraweb.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<CAPTjJmoqjTyaoO0fiN13JNiFNstWSwzOVnS2YoXT7_OyaTxuFQ@mail.gmail.com>
	<51A769F2.1050702@stoneleaf.us>
	<mailman.2429.1369929372.3114.python-list@python.org>
	<51a78113$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<51a7a706$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmoSZVxxb6i_GXkqDEkaOdUtOCcO6MqJEHCrcLBqNgahwQ@mail.gmail.com>

On Fri, May 31, 2013 at 5:22 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Thu, 30 May 2013 16:40:52 +0000, Steven D'Aprano wrote:
>
>> On Fri, 31 May 2013 01:56:09 +1000, Chris Angelico wrote:
>
>>> You're assuming you can casually hit Ctrl-C to stop an infinite loop,
>>> meaning that it's trivial. It's not. Not everything lets you do that;
>>> or possibly halting the process will halt far more than you intended.
>>> What if you're editing live code in something that's had uninterrupted
>>> uptime for over a year?
>>
>> Then more fool you for editing live code.
>
> Ouch! That came out much harsher than it sounded in my head :(
>
> Sorry Chris, that wasn't intended as a personal attack against you, just
> as a comment on the general inadvisability of modifying code on the fly
> while it is being run.

Apology accepted :)

You're right that, in theory, a staging area is a Good Thing. But it's
not always feasible. At work, we have a lot of Pike code that really
does keep running indefinitely (okay, we have yet to get anywhere near
a year's uptime for administrative reasons, but it'll be plausible
once we go live; the >1year figure came from one of my personal
projects). While all's going well, code changes follow a sane
progression:

dev -> alpha -> beta -> live

with testing at every stage. What happens when we get a problem,
though? Maybe some process is leaking resources, maybe we come under
some kind of crazy DOS attack, whatever. We need a solution, and we
need to not break things for the currently-connected clients. That
means editing the live code. Of course, there are *some* protections;
the new code won't be switched in unless it passes the compilation
phase (think "except ImportError: keep_existing_code", kinda), and
hopefully I would at least spin it up on my dev box before pushing it
to live, but even so, there's every possibility that there'll be a
specific case that I didn't think of - remembering that we're not
talking about iteration from constant to constant, but from variable
to constant or constant to variable or variable to variable. That's
why I would prefer, in language design, for a 'failed loop' to result
in no iterations than an infinite number of them. The infinite loop
might be easily caught on my dev test - but only if I pass the code
through that exact code path.

But to go back to your point about editing live code: You backed down
from the implication that it's *foolish*, but I would maintain it at a
weaker level. Editing code in a running process is a *rare* thing to
do. MOST programming is not done that way. It's like the old joke
about the car mechanic and the heart surgeon (see eg
http://www.medindia.net/jokes/viewjokes.asp?hid=200 if you haven't
heard it, and I will be spoiling the punch line in the next line or
so); most programmers are mechanics, shutting down the system to do
any work on it, but very occasionally there are times when you need to
do it with the engine running. It's like C compilers. Most of us never
write them, but a few people (relatively) actually need to drop to the
uber-low-level coding and think about how it all works in assembly
language. For everyone else, thinking about machine code is an utter
waste of time/effort, but that doesn't mean that it's folly for a
compiler writer. Does that make sense?

ChrisA


From rustompmody at gmail.com  Thu May 30 12:58:44 2013
From: rustompmody at gmail.com (rusi)
Date: Thu, 30 May 2013 09:58:44 -0700 (PDT)
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<mailman.2415.1369918710.3114.python-list@python.org>
Message-ID: <578a8e7f-4358-40ba-bcf8-d3a81b37c0d2@vy4g2000pbc.googlegroups.com>

On May 30, 5:58?pm, Chris Angelico <ros... at gmail.com> wrote:
> The alternative would be an infinite number of iterations, which is far far worse.

There was one heavyweight among programming teachers -- E.W. Dijkstra
-- who had some rather extreme views on this.

He taught that when writing a loop of the form

i = 0
while i < n:
  some code
  i += 1

one should write the loop test as i != n rather than i < n, precisely
because if i got erroneously initialized to some value greater than n,
(and thereby broke the loop invariant), it would loop infinitely
rather than stop with a wrong result.


From rosuav at gmail.com  Thu May 30 13:23:11 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 03:23:11 +1000
Subject: Short-circuit Logic
In-Reply-To: <578a8e7f-4358-40ba-bcf8-d3a81b37c0d2@vy4g2000pbc.googlegroups.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<mailman.2415.1369918710.3114.python-list@python.org>
	<578a8e7f-4358-40ba-bcf8-d3a81b37c0d2@vy4g2000pbc.googlegroups.com>
Message-ID: <CAPTjJmpoFn=DtMzceWwR3RsWpyOSMmxK0-0PEUkf4sw6D56Ahg@mail.gmail.com>

On Fri, May 31, 2013 at 2:58 AM, rusi <rustompmody at gmail.com> wrote:
> On May 30, 5:58 pm, Chris Angelico <ros... at gmail.com> wrote:
>> The alternative would be an infinite number of iterations, which is far far worse.
>
> There was one heavyweight among programming teachers -- E.W. Dijkstra
> -- who had some rather extreme views on this.
>
> He taught that when writing a loop of the form
>
> i = 0
> while i < n:
>   some code
>   i += 1
>
> one should write the loop test as i != n rather than i < n, precisely
> because if i got erroneously initialized to some value greater than n,
> (and thereby broke the loop invariant), it would loop infinitely
> rather than stop with a wrong result.

And do you agree or disagree with him? :)

I disagree with Dijkstra on a number of points, and this might be one of them.

When you consider that the obvious Pythonic version of that code:

for i in range(n,m):
    some code

loops over nothing and does not go into an infinite loop (or throw an
exception) when n >= m, you have to at least acknowledge that I'm in
agreement with Python core code here :) That doesn't mean it's right,
of course, but it's at least a viewpoint that someone has seen fit to
enshrine in important core functionality.

ChrisA


From rantingrickjohnson at gmail.com  Thu May 30 20:13:25 2013
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 30 May 2013 17:13:25 -0700 (PDT)
Subject: Short-circuit Logic
In-Reply-To: <578a8e7f-4358-40ba-bcf8-d3a81b37c0d2@vy4g2000pbc.googlegroups.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<mailman.2415.1369918710.3114.python-list@python.org>
	<578a8e7f-4358-40ba-bcf8-d3a81b37c0d2@vy4g2000pbc.googlegroups.com>
Message-ID: <9e4d113b-23ec-4eb3-836a-fc80c505c846@googlegroups.com>

> On Fri, May 31, 2013 at 2:58 AM, rusi wrote:
> > On May 30, 5:58 pm, Chris Angelico wrote:
> > > The alternative would be an infinite number of iterations, which is far far worse.
> >
> > There was one heavyweight among programming teachers -- E.W. Dijkstra
> > -- who had some rather extreme views on this.
> > 
> > He taught that when writing a loop of the form
> >
> > i = 0
> > while i < n:
> >   some code
> >   i += 1
> >
> > one should write the loop test as i != n rather than i <
> > n, precisely because if i got erroneously initialized to
> > some value greater than n, (and thereby broke the loop
> > invariant), it would loop infinitely rather than stop
> > with a wrong result.
> > 
> 
> And do you agree or disagree with him? :) I disagree with
> Dijkstra on a number of points, and this might be one of
> them. When you consider that the obvious Pythonic version
> of that code:
> 
> for i in range(n,m):
>     some code

Maybe from your limited view point. What if you need to perform operations on a sequence (more than once) in a non-linear fashion? What if you need to modify the sequence whilst looping? In many cases your simplistic "for loop" will fail miserably. 

py> lst = range(5)
py> for n in lst:
...     print lst.pop()
4
3
2

Oops, can't do that with a for loop!

py> lst = range(5)
py> while len(lst):
...     print lst.pop()
4
3
2
1
0


From rosuav at gmail.com  Thu May 30 22:29:26 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 12:29:26 +1000
Subject: Short-circuit Logic
In-Reply-To: <9e4d113b-23ec-4eb3-836a-fc80c505c846@googlegroups.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<roy-B251F4.08401630052013@news.panix.com>
	<mailman.2415.1369918710.3114.python-list@python.org>
	<578a8e7f-4358-40ba-bcf8-d3a81b37c0d2@vy4g2000pbc.googlegroups.com>
	<9e4d113b-23ec-4eb3-836a-fc80c505c846@googlegroups.com>
Message-ID: <CAPTjJmoqRyMyX0QbOBNe+NBy1x8P73WV8G02o=Hx3ci3mu_tAQ@mail.gmail.com>

On Fri, May 31, 2013 at 10:13 AM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
> What if you need to perform operations on a sequence (more than once) in a non-linear fashion? What if you need to modify the sequence whilst looping? In many cases your simplistic "for loop" will fail miserably.


What has this to do with the original question of iterating across
integers? What you're now saying is that both the meaning of the
current index and the top boundary can change during iteration; that's
unrelated to whether to use equality or inequality for comparisons.

Oh wait. Rick's back. He's been away so long that I stopped looking
for his name in the headers.

ChrisA


From neilc at norwich.edu  Thu May 30 15:30:41 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 30 May 2013 19:30:41 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
Message-ID: <b0pnn1F6r6uU1@mid.individual.net>

On 2013-05-30, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, May 30, 2013 at 3:10 PM, Steven D'Aprano
><steve+comp.lang.python at pearwood.info> wrote:
>> # Wrong, don't do this!
>> x = 0.1
>> while x != 17.3:
>>     print(x)
>>     x += 0.1
>
> Actually, I wouldn't do that with integers either.

I propose borrowing the concept of significant digits from the
world of Physics.

The above has at least three significant digits. With that scheme
x would approximately equal 17.3 when 17.25 <= x < 17.35.

But I don't see immediately how to calculate 17.25 and 17.35 from
17.3, 00.1 and 3 significant digits.

-- 
Neil Cerutti


From ian.g.kelly at gmail.com  Thu May 30 15:49:43 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 30 May 2013 13:49:43 -0600
Subject: Short-circuit Logic
In-Reply-To: <b0pnn1F6r6uU1@mid.individual.net>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com>
	<51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com>
	<04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com>
	<51a6df59$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2395.1369891346.3114.python-list@python.org>
	<b0pnn1F6r6uU1@mid.individual.net>
Message-ID: <CALwzidk4LDUpdLX9kHsjZHQYMFq+DzPGg7WunhNu8i_Rz2cF3g@mail.gmail.com>

On Thu, May 30, 2013 at 1:30 PM, Neil Cerutti <neilc at norwich.edu> wrote:
> On 2013-05-30, Chris Angelico <rosuav at gmail.com> wrote:
>> On Thu, May 30, 2013 at 3:10 PM, Steven D'Aprano
>><steve+comp.lang.python at pearwood.info> wrote:
>>> # Wrong, don't do this!
>>> x = 0.1
>>> while x != 17.3:
>>>     print(x)
>>>     x += 0.1
>>
>> Actually, I wouldn't do that with integers either.
>
> I propose borrowing the concept of significant digits from the
> world of Physics.
>
> The above has at least three significant digits. With that scheme
> x would approximately equal 17.3 when 17.25 <= x < 17.35.
>
> But I don't see immediately how to calculate 17.25 and 17.35 from
> 17.3, 00.1 and 3 significant digits.

How about this:

while round(x, 1) != round(17.3, 1):
    pass

The second round call may be unnecessary.  I would expect the parser
to ensure that round(17.3, 1) == 17.3, but I'm not certain that is the
case.


From tjreedy at udel.edu  Sun May 26 16:19:17 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 26 May 2013 16:19:17 -0400
Subject: Short-circuit Logic
In-Reply-To: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
Message-ID: <kntqnn$l49$1@ger.gmane.org>

On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote:

>       if not allow_zero and abs(x) < sys.float_info.epsilon:
>                  print("zero is not allowed")

The reason for the order is to do the easy calculation first and the 
harder one only if the first passes.





From roy at panix.com  Sun May 26 16:22:26 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 26 May 2013 16:22:26 -0400
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<mailman.2196.1369599562.3114.python-list@python.org>
Message-ID: <roy-31D5CD.16222626052013@news.panix.com>

In article <mailman.2196.1369599562.3114.python-list at python.org>,
 Terry Jan Reedy <tjreedy at udel.edu> wrote:

> On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote:
> 
> >       if not allow_zero and abs(x) < sys.float_info.epsilon:
> >                  print("zero is not allowed")
> 
> The reason for the order is to do the easy calculation first and the 
> harder one only if the first passes.

This is a particularly egregious case of premature optimization.  You're 
worried about how long it takes to execute abs(x)?  That's silly.


From roy at panix.com  Sun May 26 16:22:26 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 26 May 2013 16:22:26 -0400
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<mailman.2196.1369599562.3114.python-list@python.org>
Message-ID: <roy-31D5CD.16222626052013@news.panix.com>

In article <mailman.2196.1369599562.3114.python-list at python.org>,
 Terry Jan Reedy <tjreedy at udel.edu> wrote:

> On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote:
> 
> >       if not allow_zero and abs(x) < sys.float_info.epsilon:
> >                  print("zero is not allowed")
> 
> The reason for the order is to do the easy calculation first and the 
> harder one only if the first passes.

This is a particularly egregious case of premature optimization.  You're 
worried about how long it takes to execute abs(x)?  That's silly.


From tjreedy at udel.edu  Sun May 26 17:28:56 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 26 May 2013 17:28:56 -0400
Subject: Short-circuit Logic
In-Reply-To: <roy-31D5CD.16222626052013@news.panix.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<mailman.2196.1369599562.3114.python-list@python.org>
	<roy-31D5CD.16222626052013@news.panix.com>
Message-ID: <kntuqb$sp7$1@ger.gmane.org>

On 5/26/2013 4:22 PM, Roy Smith wrote:
> In article <mailman.2196.1369599562.3114.python-list at python.org>,
>   Terry Jan Reedy <tjreedy at udel.edu> wrote:
>
>> On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote:
>>
>>>        if not allow_zero and abs(x) < sys.float_info.epsilon:
>>>                   print("zero is not allowed")
>>
>> The reason for the order is to do the easy calculation first and the
>> harder one only if the first passes.
>
> This is a particularly egregious case of premature optimization.  You're
> worried about how long it takes to execute abs(x)?  That's silly.

This is a particularly egregious case of premature response. You're 
ignoring an extra name lookup and two extra attribute lookups. That's silly.

That's beside the fact that one *must* choose, so any difference is a 
reason to act rather than being frozen like Buridan's ass.
http://en.wikipedia.org/wiki/Buridan%27s_ass

If you wish, replace 'The reason' with 'A reason'. I also the logical 
flow as better with the order given.







From steve+comp.lang.python at pearwood.info  Sun May 26 20:40:07 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 27 May 2013 00:40:07 GMT
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<mailman.2196.1369599562.3114.python-list@python.org>
	<roy-31D5CD.16222626052013@news.panix.com>
Message-ID: <51a2ab67$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Sun, 26 May 2013 16:22:26 -0400, Roy Smith wrote:

> In article <mailman.2196.1369599562.3114.python-list at python.org>,
>  Terry Jan Reedy <tjreedy at udel.edu> wrote:
> 
>> On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote:
>> 
>> >       if not allow_zero and abs(x) < sys.float_info.epsilon:
>> >                  print("zero is not allowed")
>> 
>> The reason for the order is to do the easy calculation first and the
>> harder one only if the first passes.
> 
> This is a particularly egregious case of premature optimization.  You're
> worried about how long it takes to execute abs(x)?  That's silly.

I don't think it's a matter of premature optimization so much as the 
general principle "run code only if it needs to run". Hence, first you 
check the flag to decide whether or not you care whether x is near zero, 
and *only if you care* do you then check whether x is near zero.

# This is silly:
if x is near zero:
    if we care:
        handle near zero condition()

# This is better:
if we care:
    if x is near zero
        handle near zero condition()


Not only is this easier to understand because it matches how we do things 
in the real life, but it has the benefit that if the "near zero" 
condition ever changes to become much more expensive, you don't have to 
worry about reordering the tests because they're already in the right 
order.



-- 
Steven


From cs at zip.com.au  Sun May 26 21:57:54 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 27 May 2013 11:57:54 +1000
Subject: Short-circuit Logic
In-Reply-To: <51a2ab67$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <51a2ab67$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20130527015754.GA81324@cskk.homeip.net>

On 27May2013 00:40, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
| On Sun, 26 May 2013 16:22:26 -0400, Roy Smith wrote:
| 
| > In article <mailman.2196.1369599562.3114.python-list at python.org>,
| >  Terry Jan Reedy <tjreedy at udel.edu> wrote:
| > 
| >> On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote:
| >> 
| >> >       if not allow_zero and abs(x) < sys.float_info.epsilon:
| >> >                  print("zero is not allowed")
| >> 
| >> The reason for the order is to do the easy calculation first and the
| >> harder one only if the first passes.
| > 
| > This is a particularly egregious case of premature optimization.  You're
| > worried about how long it takes to execute abs(x)?  That's silly.
| 
| I don't think it's a matter of premature optimization so much as the 
| general principle "run code only if it needs to run". Hence, first you 
| check the flag to decide whether or not you care whether x is near zero, 
| and *only if you care* do you then check whether x is near zero.
| 
| # This is silly:
| if x is near zero:
|     if we care:
|         handle near zero condition()
| 
| # This is better:
| if we care:
|     if x is near zero
|         handle near zero condition()
| 
| 
| Not only is this easier to understand because it matches how we do things 
| in the real life, but it has the benefit that if the "near zero" 
| condition ever changes to become much more expensive, you don't have to 
| worry about reordering the tests because they're already in the right 
| order.

I wouldn't even go that far, though nothing you say above is wrong.

Terry's assertion "The reason for the order is to do the easy
calculation first and the harder one only if the first passes" is
only sometimes that case, though well worth considering if the
second test _is_ expensive.

There are other reasons also. The first is of course your response,
that if the first test fails there's no need to even bother with
the second one. Faster, for free!

The second is that sometimes the first test is a guard against even
being able to perform the second test. Example:

  if s is not None and len(s) > 0:
    ... do something with the non-empty string `s` ...

In this example, None is a sentinel value for "no valid string" and
calling "len(s)" would raise an exception because None doesn't have
a length.

With short circuiting logic you can write this clearly and intuitively in one line
without extra control structure like the nested ifs above.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Who are all you people and why are you in my computer?  - Kibo


From vito.detullio at gmail.com  Mon May 27 00:59:13 2013
From: vito.detullio at gmail.com (Vito De Tullio)
Date: Mon, 27 May 2013 06:59:13 +0200
Subject: Short-circuit Logic
References: <51a2ab67$0$30002$c3e8da3$5496439d@news.astraweb.com>
	<20130527015754.GA81324@cskk.homeip.net>
Message-ID: <knup72$juf$1@ger.gmane.org>

Cameron Simpson wrote:

>   if s is not None and len(s) > 0:
>     ... do something with the non-empty string `s` ...
> 
> In this example, None is a sentinel value for "no valid string" and
> calling "len(s)" would raise an exception because None doesn't have
> a length.

obviously in this case an `if s: ...` is more than sufficient :P

-- 
ZeD



From cs at zip.com.au  Mon May 27 02:13:20 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 27 May 2013 16:13:20 +1000
Subject: Short-circuit Logic
In-Reply-To: <knup72$juf$1@ger.gmane.org>
References: <knup72$juf$1@ger.gmane.org>
Message-ID: <20130527061320.GA44368@cskk.homeip.net>

On 27May2013 06:59, Vito De Tullio <vito.detullio at gmail.com> wrote:
| Cameron Simpson wrote:
| >   if s is not None and len(s) > 0:
| >     ... do something with the non-empty string `s` ...
| > 
| > In this example, None is a sentinel value for "no valid string" and
| > calling "len(s)" would raise an exception because None doesn't have
| > a length.
| 
| obviously in this case an `if s: ...` is more than sufficient :P

:P

My fault for picking too similar a test.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Death is life's way of telling you you've been fired.   - R. Geis


From rustompmody at gmail.com  Mon May 27 00:44:30 2013
From: rustompmody at gmail.com (rusi)
Date: Sun, 26 May 2013 21:44:30 -0700 (PDT)
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
	<mailman.2196.1369599562.3114.python-list@python.org>
	<roy-31D5CD.16222626052013@news.panix.com>
	<51a2ab67$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <80c667ec-429d-469d-b69f-1b3effc4a0ef@zo5g2000pbb.googlegroups.com>

On May 27, 5:40?am, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
> On Sun, 26 May 2013 16:22:26 -0400, Roy Smith wrote:
> > In article <mailman.2196.1369599562.3114.python-l... at python.org>,
> > ?Terry Jan Reedy <tjre... at udel.edu> wrote:
>
> >> On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote:
>
> >> > ? ? ? if not allow_zero and abs(x) < sys.float_info.epsilon:
> >> > ? ? ? ? ? ? ? ? ?print("zero is not allowed")
>
> >> The reason for the order is to do the easy calculation first and the
> >> harder one only if the first passes.
>
> > This is a particularly egregious case of premature optimization. ?You're
> > worried about how long it takes to execute abs(x)? ?That's silly.
>
> I don't think it's a matter of premature optimization so much as the
> general principle "run code only if it needs to run". Hence, first you
> check the flag to decide whether or not you care whether x is near zero,
> and *only if you care* do you then check whether x is near zero.
>
> # This is silly:
> if x is near zero:
> ? ? if we care:
> ? ? ? ? handle near zero condition()
>
> # This is better:
> if we care:
> ? ? if x is near zero
> ? ? ? ? handle near zero condition()
>
> Not only is this easier to understand because it matches how we do things
> in the real life, but it has the benefit that if the "near zero"
> condition ever changes to become much more expensive, you don't have to
> worry about reordering the tests because they're already in the right
> order.
>
> --
> Steven

Three points:

3. These arguments are based on a certain assumption: that the inputs
are evenly distributed statistically.
If however that is not so, ie say:
"We-care" is mostly true
and
"x-is-near-zero" is more often false
then doing the near-zero test first would be advantageous

Well thats the 3rd point...

2. Nikalus Wirth deliberately did not use short-circuit boolean
operators in his languages because he found these kind of distinctions
to deteriorate into irrelevance and miss out the more crucial
questions of correctness

1. As Roy pointed out in his initial response to the OP:
"I dont understand your confusion... None of <the above> applies to
your example"
its not at all clear to me that anything being said has anything to do
with what the OP asked!


From nobody at nowhere.com  Mon May 27 13:52:15 2013
From: nobody at nowhere.com (Nobody)
Date: Mon, 27 May 2013 18:52:15 +0100
Subject: Short-circuit Logic
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
Message-ID: <pan.2013.05.27.17.52.14.263000@nowhere.com>

On Sun, 26 May 2013 04:11:56 -0700, Ahmed Abdulshafy wrote:

> I'm having a hard time wrapping my head around short-circuit logic that's
> used by Python, coming from a C/C++ background; so I don't understand why
> the following condition is written this way!>
> 
>      if not allow_zero and abs(x) < sys.float_info.epsilon:
>                 print("zero is not allowed")
> 
> The purpose of this snippet is to print the given line when allow_zero is
> False and x is 0.

I don't understand your confusion. The above is directly equivalent to the
following C code:

	if (!allow_zero && fabs(x) < DBL_EPSILON)
	    printf("zero is not allowed\n");

In either case, the use of short-circuit evaluation isn't necessary here;
it would work just as well with a strict[1] "and" operator.

Short-circuit evaluation is useful if the second argument is expensive to
compute, or (more significantly) if the second argument should not be
evaluated if the first argument is false; e.g. if x is a pointer then:

	if (x && *x) ...

relies upon short-circuit evaluation to avoid dereferencing a null pointer.

On an unrelated note: the use of the "epsilon" value here is
almost certainly wrong. If the intention is to determine if the result of
a calculation is zero to within the limits of floating-point accuracy,
then it should use a value which is proportional to the values used in
the calculation.



From abdulshafy at gmail.com  Mon May 27 16:08:34 2013
From: abdulshafy at gmail.com (Ahmed Abdulshafy)
Date: Mon, 27 May 2013 13:08:34 -0700 (PDT)
Subject: Short-circuit Logic
In-Reply-To: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
References: <5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com>
Message-ID: <e49eb37c-a11f-4280-9aad-82056b30347c@googlegroups.com>

On Sunday, May 26, 2013 1:11:56 PM UTC+2, Ahmed Abdulshafy wrote:
> Hi,
> 
> I'm having a hard time wrapping my head around short-circuit logic that's used by Python, coming from a C/C++ background; so I don't understand why the following condition is written this way!>
> 
> 
> 
>      if not allow_zero and abs(x) < sys.float_info.epsilon:
> 
>                 print("zero is not allowed")
> 
> 
> 
> The purpose of this snippet is to print the given line when allow_zero is False and x is 0.

Thank you guys! you gave me valuable insights! But regarding my original post, I don't know why for the past two days I was looking at the code *only* this way>
     if ( not allow_zero and abs(x) ) < sys.float_info.epsilon:

I feel so stupid now :-/, may be it's the new syntax confusing me :)! Thanks again guys.


From nikos.gr33k at gmail.com  Sun May 26 07:11:56 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 04:11:56 -0700 (PDT)
Subject: Error when trying to sort and presnt a dictionary in python 3.3.1
Message-ID: <95e674bf-0d96-479c-b7a4-9242768a7a46@googlegroups.com>

python3 pelatologio.py gives  me error in this line:

Traceback (most recent call last):
  File "pelatologio.py", line 283, in &lt;module&gt;
    ''' % (months[key], key) )
KeyError: 1

The code is:

#populating months into a dropdown menu
years = ( 2010, 2011, 2012, 2013 )
months = { '??????????':1, '???????????':2, '???????':3, '????????':4, '?????':5, '???????':6, \
	   '???????':7, '?????????':8, '???????????':9, '?????????':10, '?????????':11, '??????????':12 }

print('''
<form method="post" action="">
	<select name="month">
''')
	
for key in sorted( months.values() ):
	print('''
		<option value="%s"> %s </option>
	''' % (months[key], key) )


From __peter__ at web.de  Sun May 26 08:20:19 2013
From: __peter__ at web.de (Peter Otten)
Date: Sun, 26 May 2013 14:20:19 +0200
Subject: Error when trying to sort and presnt a dictionary in python 3.3.1
References: <95e674bf-0d96-479c-b7a4-9242768a7a46@googlegroups.com>
Message-ID: <knsukm$e4n$1@ger.gmane.org>

????? ???33? wrote:

> python3 pelatologio.py gives  me error in this line:
> 
> Traceback (most recent call last):
>   File "pelatologio.py", line 283, in &lt;module&gt;
>     ''' % (months[key], key) )
> KeyError: 1
> 
> The code is:
> 
> #populating months into a dropdown menu
> years = ( 2010, 2011, 2012, 2013 )
> months = { '??????????':1, '???????????':2, '???????':3, '????????':4,
> '?????':5, '???????':6, \ '???????':7, '?????????':8, '???????????':9,
> '?????????':10, '?????????':11, '??????????':12 }

You have keys and values mixed up...
 
> print('''
> <form method="post" action="">
> <select name="month">
> ''')
> 
> for key in sorted( months.values() ):

and calling the value key doesn't help there.

> print('''
> <option value="%s"> %s </option>
> ''' % (months[key], key) )

At some point you have to admit that coding isn't your cup of tea.
Or Ouzo ;(



From nikos.gr33k at gmail.com  Sun May 26 08:58:12 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 05:58:12 -0700 (PDT)
Subject: Error when trying to sort and presnt a dictionary in python 3.3.1
In-Reply-To: <mailman.2172.1369570798.3114.python-list@python.org>
References: <95e674bf-0d96-479c-b7a4-9242768a7a46@googlegroups.com>
	<mailman.2172.1369570798.3114.python-list@python.org>
Message-ID: <9ea1331c-2c23-43db-a4d0-68f6cdd5f321@googlegroups.com>

?? ???????, 26 ????? 2013 3:20:19 ?.?. UTC+3, ? ??????? Peter Otten ??????:

> At some point you have to admit that coding isn't your cup of tea.
> Or Ouzo ;(

And i didn't evne drank anyhting, iam sober! Imagine what i would have written if i had some shots of Ouzo :-)

I chnage my code to:

months = { '??????????':1, '???????????':2, '???????':3, '????????':4, '?????':5, '???????':6, \
	   '???????':7, '?????????':8, '???????????':9, '?????????':10, '?????????':11, '??????????':12 }

print('''
<form method="post" action="">
	<select name="month">
''')
	
for key in sorted( months.keys() ):
	print('''
		<option value="%s"> %s </option>
	''' % (months[key], key) )
				
print('''
	</select> '''


Now, iam not getting any eroor from cmd when i 'python3 pelatologio.py' verythign interprets normally wiyohut an error.

BUT i kepp getting an internal server error when i try to run the script via a browser (Chrome).

python3 path is ok
uploaded as ascii
chmoded to 755 ok.

How in cmd i get no error while on browser i get internal server error?


From nikos.gr33k at gmail.com  Sun May 26 12:09:11 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 09:09:11 -0700 (PDT)
Subject: Error when trying to sort and presnt a dictionary in python 3.3.1
In-Reply-To: <9ea1331c-2c23-43db-a4d0-68f6cdd5f321@googlegroups.com>
References: <95e674bf-0d96-479c-b7a4-9242768a7a46@googlegroups.com>
	<mailman.2172.1369570798.3114.python-list@python.org>
	<9ea1331c-2c23-43db-a4d0-68f6cdd5f321@googlegroups.com>
Message-ID: <d99cbc52-d2c4-4ace-9be7-c13f43bfab73@googlegroups.com>

?? ???????, 26 ????? 2013 3:58:12 ?.?. UTC+3, ? ??????? ????? ???33? ??????:
> ?? ???????, 26 ????? 2013 3:20:19 ?.?. UTC+3, ? ??????? Peter Otten ??????:
> 
> 
> 
> > At some point you have to admit that coding isn't your cup of tea.
> 
> > Or Ouzo ;(
> 
> 
> 
> And i didn't evne drank anyhting, iam sober! Imagine what i would have written if i had some shots of Ouzo :-)
> 
> 
> 
> I chnage my code to:
> 
> 
> 
> months = { '??????????':1, '???????????':2, '???????':3, '????????':4, '?????':5, '???????':6, \
> 
> 	   '???????':7, '?????????':8, '???????????':9, '?????????':10, '?????????':11, '??????????':12 }
> 
> 
> 
> print('''
> 
> <form method="post" action="">
> 
> 	<select name="month">
> 
> ''')
> 
> 	
> 
> for key in sorted( months.keys() ):
> 
> 	print('''
> 
> 		<option value="%s"> %s </option>
> 
> 	''' % (months[key], key) )
> 
> 				
> 
> print('''
> 
> 	</select> '''
> 
> 
> 
> 
> 
> Now, iam not getting any eroor from cmd when i 'python3 pelatologio.py' verythign interprets normally wiyohut an error.
> 
> 
> 
> BUT i kepp getting an internal server error when i try to run the script via a browser (Chrome).
> 
> 
> 
> python3 path is ok
> 
> uploaded as ascii
> 
> chmoded to 755 ok.
> 
> 
> 
> How in cmd i get no error while on browser i get internal server error?

Its okey i made it work, it wasnt an actuap python issue but an .htaccess and .htpasswd problem.

All fine now!


From peter.h.m.brooks at gmail.com  Sun May 26 07:49:57 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Sun, 26 May 2013 04:49:57 -0700 (PDT)
Subject: Solving the problem of mutual recursion
Message-ID: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>

I'm not sure if this'll interest anybody, but I expect that I'm going
to get some mutual recursion in my simulation, so I needed to see how
python handled it. Unfortunately, it falls over once it detects a
certain level of recursion. This is reasonable as, otherwise, the
stack eventually over-fills.

Mostly the recommendation, when this happens, is to re-write the code
as loops. Of course, that's not as satisfactory as using recursion.

The problem really is that the methods or functions called recursively
never exit because they're waiting for the return of the function
they've called. Now, if your recursion relies upon knowing what's
returned, then this solution won't help you. Often, though, you're not
interested in what's returned and would just like the routine to exit
once it's called itself, or another process, recursively.

If that's the case, this solution, using threads, allows you to have
functions call themselves, or each other, indefinitely. It works OK on
a macbook pro and the thread count varies from 2-3, so it handles the
thread queuing well. I'm not sure how well this will work on other
architecture - it'd be interesting to know if anybody tries it.

#!/usr/bin/python
# Two functions, Jim and Fred, call each other recursively and
indefinitely, while the main program continues to execute as well
import threading, time

def jim(arg,count):
        print "Running jim:", arg,count," Thread Count
",threading.active_count()
        thread = threading.Thread(target=fred, args=(" From Jim ",count
+1))
        thread.start()
        print count," Jim complete. Thread
Count",threading.active_count()

def fred(arg,counter):
        print "Running fred:", arg,counter
        thread = threading.Thread(target=jim, args=(" From Fred
",counter+1))
        thread.start()
        print counter,"Fred complete",threading.currentThread()


thread = threading.Thread(target=jim, args=(" From Main",0))
thread.start()
print "Jim run from main"
count = 0
while True:
        count += 1
        print 'In main program',count


From jpiitula at ling.helsinki.fi  Sun May 26 11:09:27 2013
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 26 May 2013 18:09:27 +0300
Subject: Solving the problem of mutual recursion
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
Message-ID: <qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>

Peter Brooks writes:

> I'm not sure if this'll interest anybody, but I expect that I'm
> going to get some mutual recursion in my simulation, so I needed to
...
> returned, then this solution won't help you. Often, though, you're
> not interested in what's returned and would just like the routine to
> exit once it's called itself, or another process, recursively.
> 
> If that's the case, this solution, using threads, allows you to have
> functions call themselves, or each other, indefinitely. It works OK
> on a macbook pro and the thread count varies from 2-3, so it handles

... hard to resist ... but somehow I manage ... whew ...

A light-weighter way is to have each task end by assigning the next
task and returning, instead of calling the next task directly. When a
task returns, a driver loop will call the assigned task, which again
does a bounded amount of work, assigns the next task, and returns.
Tasks can even pass parameters in the same way.

Like so, Dr. Fred keeps adding to a pile as long as there is a pile,
and Mr. Jim keeps taking from it as long as it's there to take from:

from random import choice

def fred():
    global fun, arg
    print('Fred adds 1')
    fun, arg = choice((fred, jim)), arg + 1

def jim():
    global fun, arg
    print('Jim takes 1')
    fun, arg = choice((fred, jim)), arg - 1

if __name__ == '__main__':
    fun, arg = choice((fred, jim)), 3
    while arg:
        print('Pile is', arg, end = '\t')
        fun()
    else:
        print('Pile is gone')


From roy at panix.com  Sun May 26 11:23:04 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 26 May 2013 11:23:04 -0400
Subject: Solving the problem of mutual recursion
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>
Message-ID: <roy-D330DF.11230426052013@news.panix.com>

In article <qota9nhu6ag.fsf at ruuvi.it.helsinki.fi>,
 Jussi Piitulainen <jpiitula at ling.helsinki.fi> wrote:

> A light-weighter way is to have each task end by assigning the next
> task and returning, instead of calling the next task directly. When a
> task returns, a driver loop will call the assigned task, which again
> does a bounded amount of work, assigns the next task, and returns.
> Tasks can even pass parameters in the same way.

Yup.  I've used this pattern for building state machines.  Each state is 
a function which returns the next state (or, sometimes, a (next_state, 
output) tuple).  The top level loop ends up looking very much like yours:

state = start
while state != end:
   state, output = state(get_next_input())
   print output


> 
> Like so, Dr. Fred keeps adding to a pile as long as there is a pile,
> and Mr. Jim keeps taking from it as long as it's there to take from:
> 
> from random import choice
> 
> def fred():
>     global fun, arg
>     print('Fred adds 1')
>     fun, arg = choice((fred, jim)), arg + 1
> 
> def jim():
>     global fun, arg
>     print('Jim takes 1')
>     fun, arg = choice((fred, jim)), arg - 1
> 
> if __name__ == '__main__':
>     fun, arg = choice((fred, jim)), 3
>     while arg:
>         print('Pile is', arg, end = '\t')
>         fun()
>     else:
>         print('Pile is gone')


From peter.h.m.brooks at gmail.com  Sun May 26 13:21:05 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Sun, 26 May 2013 10:21:05 -0700 (PDT)
Subject: Solving the problem of mutual recursion
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>
Message-ID: <d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>

On May 26, 5:09?pm, Jussi Piitulainen <jpiit... at ling.helsinki.fi>
wrote:
>
> A light-weighter way is to have each task end by assigning the next
> task and returning, instead of calling the next task directly. When a
> task returns, a driver loop will call the assigned task, which again
> does a bounded amount of work, assigns the next task, and returns.
> Tasks can even pass parameters in the same way.
>
Yes, that's true - there are a number of ways of making it linear.

What I'm particularly pleased about with my method is the parallelism
that it achieves - with so little effort! The simulation is going to
be computationally intense and this is going to make sure that the
CPUs are all giving it their best shot. When I run this on my macbook,
the python interpreter takes over 140% of CPU - with a bit of fine-
tuning, it should be possible to have more concurrent threads and to
use the four cores optimally.

Naturally I'll need to be careful with the concurrency, but this is so
simple and clean that it should be easy to avoid the main problems
with accessing the same variables.


From carlosnepomuceno at outlook.com  Sun May 26 14:09:29 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 21:09:29 +0300
Subject: Solving the problem of mutual recursion
In-Reply-To: <d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>,
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>,
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
Message-ID: <BLU176-W28AC6BD8FE1DDD7431A353D7950@phx.gbl>

----------------------------------------
> Date: Sun, 26 May 2013 10:21:05 -0700
> Subject: Re: Solving the problem of mutual recursion
> From: peter.h.m.brooks at gmail.com
> To: python-list at python.org
>
> On May 26, 5:09 pm, Jussi Piitulainen <jpiit... at ling.helsinki.fi>
> wrote:
>>
>> A light-weighter way is to have each task end by assigning the next
>> task and returning, instead of calling the next task directly. When a
>> task returns, a driver loop will call the assigned task, which again
>> does a bounded amount of work, assigns the next task, and returns.
>> Tasks can even pass parameters in the same way.
>>
> Yes, that's true - there are a number of ways of making it linear.
>
> What I'm particularly pleased about with my method is the parallelism
> that it achieves - with so little effort! The simulation is going to
> be computationally intense and this is going to make sure that the
> CPUs are all giving it their best shot. When I run this on my macbook,
> the python interpreter takes over 140% of CPU - with a bit of fine-
> tuning, it should be possible to have more concurrent threads and to
> use the four cores optimally.
>
> Naturally I'll need to be careful with the concurrency, but this is so
> simple and clean that it should be easy to avoid the main problems
> with accessing the same variables.
> --
> http://mail.python.org/mailman/listinfo/python-list

Python threads run in the same process and won't run concurrently:

"CPython implementation detail: In CPython, due to the Global Interpreter Lock, only one thread can execute Python code at once (even though certain performance-oriented libraries might overcome this limitation). If you want your application to make better use of the computational resources of multi-core machines, you are advised to use multiprocessing. However, threading is still an appropriate model if you want to run multiple I/O-bound tasks simultaneously."[1]

How can you get 140% of CPU? IS that a typo??

[1] http://docs.python.org/2/library/threading.html 		 	   		  

From peter.h.m.brooks at gmail.com  Sun May 26 14:13:12 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Sun, 26 May 2013 11:13:12 -0700 (PDT)
Subject: Solving the problem of mutual recursion
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>,
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>,
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
	<mailman.2185.1369591777.3114.python-list@python.org>
Message-ID: <074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>

On 26 May, 20:09, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
wrote:
> ----------------------------------------
>
>
>
>
>
>
>
>
>
> > Date: Sun, 26 May 2013 10:21:05 -0700
> > Subject: Re: Solving the problem of mutual recursion
> > From: peter.h.m.bro... at gmail.com
> > To: python-l... at python.org
>
> > On May 26, 5:09 pm, Jussi Piitulainen <jpiit... at ling.helsinki.fi>
> > wrote:
>
> >> A light-weighter way is to have each task end by assigning the next
> >> task and returning, instead of calling the next task directly. When a
> >> task returns, a driver loop will call the assigned task, which again
> >> does a bounded amount of work, assigns the next task, and returns.
> >> Tasks can even pass parameters in the same way.
>
> > Yes, that's true - there are a number of ways of making it linear.
>
> > What I'm particularly pleased about with my method is the parallelism
> > that it achieves - with so little effort! The simulation is going to
> > be computationally intense and this is going to make sure that the
> > CPUs are all giving it their best shot. When I run this on my macbook,
> > the python interpreter takes over 140% of CPU - with a bit of fine-
> > tuning, it should be possible to have more concurrent threads and to
> > use the four cores optimally.
>
> > Naturally I'll need to be careful with the concurrency, but this is so
> > simple and clean that it should be easy to avoid the main problems
> > with accessing the same variables.
> > --
> >http://mail.python.org/mailman/listinfo/python-list
>
> Python threads run in the same process and won't run concurrently:
>
> "CPython implementation detail: In CPython, due to the Global Interpreter Lock, only one thread can execute Python code at once (even though certain performance-oriented libraries might overcome this limitation). If you want your application to make better use of the computational resources of multi-core machines, you are advised to use multiprocessing. However, threading is still an appropriate model if you want to run multiple I/O-bound tasks simultaneously."[1]
>
> How can you get 140% of CPU? IS that a typo??
>
No, on a multi-core machine it's normal. The machine shows python
running multiple threads - and the number of threads change as the
program runs. Perhaps the OS/X implementation of python does allow
concurrency when others don't. It certainly looks like it!




From carlosnepomuceno at outlook.com  Sun May 26 14:22:19 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 21:22:19 +0300
Subject: Solving the problem of mutual recursion
In-Reply-To: <074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>,
	, <qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>, ,
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>,
	<mailman.2185.1369591777.3114.python-list@python.org>,
	<074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
Message-ID: <BLU176-W12B02BE931AE460D8F66B8D7950@phx.gbl>

----------------------------------------
> Date: Sun, 26 May 2013 11:13:12 -0700
> Subject: Re: Solving the problem of mutual recursion
> From: peter.h.m.brooks at gmail.com
> To: python-list at python.org
[...]
>> How can you get 140% of CPU? IS that a typo??
>>
> No, on a multi-core machine it's normal. The machine shows python
> running multiple threads - and the number of threads change as the
> program runs. Perhaps the OS/X implementation of python does allow
> concurrency when others don't. It certainly looks like it!


I pretty sure it doesn't run on multiple cores on Linux and Windows.

I've tested it and have been trying to find a better way achieve concurrency in Python. One of the ways is the multiprocessing module[1].

Do Mac OS shows "140%" CPU load when more than a single core is been used? lol Apple sucks!!! lol


[1] http://docs.python.org/2/library/multiprocessing.html 		 	   		  

From peter.h.m.brooks at gmail.com  Sun May 26 15:05:02 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Sun, 26 May 2013 12:05:02 -0700 (PDT)
Subject: Solving the problem of mutual recursion
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>,
	, <qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>, ,
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>,
	<mailman.2185.1369591777.3114.python-list@python.org>,
	<074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
	<mailman.2187.1369592548.3114.python-list@python.org>
Message-ID: <569927ff-876b-499f-99f8-7d27ccb27809@l3g2000vbl.googlegroups.com>

On 26 May, 20:22, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
wrote:
> ----------------------------------------
>
> > Date: Sun, 26 May 2013 11:13:12 -0700
> > Subject: Re: Solving the problem of mutual recursion
> > From: peter.h.m.bro... at gmail.com
> > To: python-l... at python.org
> [...]
> >> How can you get 140% of CPU? IS that a typo??
>
> > No, on a multi-core machine it's normal. The machine shows python
> > running multiple threads - and the number of threads change as the
> > program runs. Perhaps the OS/X implementation of python does allow
> > concurrency when others don't. It certainly looks like it!
>
> I pretty sure it doesn't run on multiple cores on Linux and Windows.
>
> I've tested it and have been trying to find a better way achieve concurrency in Python. One of the ways is the multiprocessing module[1].
>
> Do Mac OS shows "140%" CPU load when more than a single core is been used? lol Apple sucks!!! lol
>
It's not uncommon - HP-UX does exactly the same thing.


From ian.g.kelly at gmail.com  Sun May 26 15:35:52 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sun, 26 May 2013 13:35:52 -0600
Subject: Solving the problem of mutual recursion
In-Reply-To: <074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
	<mailman.2185.1369591777.3114.python-list@python.org>
	<074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
Message-ID: <CALwzidkUtWZvVvdKhU7usYw2e926z4XT_hvHTKOQbDGmmLMCQg@mail.gmail.com>

On Sun, May 26, 2013 at 12:13 PM, Peter Brooks
<peter.h.m.brooks at gmail.com> wrote:
> No, on a multi-core machine it's normal. The machine shows python
> running multiple threads - and the number of threads change as the
> program runs. Perhaps the OS/X implementation of python does allow
> concurrency when others don't. It certainly looks like it!

I'm pretty sure that CPython uses the GIL regardless of platform.  And
yes you can have multiple OS-level threads, but because of the GIL
only one will actually be running at a time.  Other possibilities
include:

1) You're using a different implementation of Python that does not
have a GIL, e.g. Jython or IronPython (well, probably not the latter).
 I believe PyPy also has a GIL-less version, although I don't think
this is in the current release yet.

2) You're using a fork of CPython that removes the GIL.  There are a
number of these, but none to my knowledge that are able to maintain
the performance of CPython for a single thread.

3) You're mistakenly looking at multiple Python processes that are
running simultaneously and adding their usages together.

4) The utility you're using is reporting the process CPU usage incorrectly.

5) Maybe for some reason the Mac OS X build of CPython is using
spin-locks in the GIL.  I can't imagine why this would be the case.


From rosuav at gmail.com  Sun May 26 18:16:34 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 08:16:34 +1000
Subject: Solving the problem of mutual recursion
In-Reply-To: <CALwzidkUtWZvVvdKhU7usYw2e926z4XT_hvHTKOQbDGmmLMCQg@mail.gmail.com>
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
	<mailman.2185.1369591777.3114.python-list@python.org>
	<074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
	<CALwzidkUtWZvVvdKhU7usYw2e926z4XT_hvHTKOQbDGmmLMCQg@mail.gmail.com>
Message-ID: <CAPTjJmrN_FHKUhq37xUnMCu+P7N6j5Pde8P8qMpDXpovTMp77w@mail.gmail.com>

On Mon, May 27, 2013 at 5:35 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> I'm pretty sure that CPython uses the GIL regardless of platform.  And
> yes you can have multiple OS-level threads, but because of the GIL
> only one will actually be running at a time.  Other possibilities
> include:

6) It's spinning in a function that has released the GIL. Python
threads can certainly execute concurrently; they just can't be
manipulating Python objects. Most of the I/O functions will release
the GIL before doing a potentially-blocking operation, and some
CPU-heavy functions can do the same (I'm given to understand that
numpy does this) - just depends on having a long job that involves no
refcounted objects.

ChrisA


From ian.g.kelly at gmail.com  Mon May 27 02:19:30 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 27 May 2013 00:19:30 -0600
Subject: Solving the problem of mutual recursion
In-Reply-To: <CAPTjJmrN_FHKUhq37xUnMCu+P7N6j5Pde8P8qMpDXpovTMp77w@mail.gmail.com>
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
	<mailman.2185.1369591777.3114.python-list@python.org>
	<074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
	<CALwzidkUtWZvVvdKhU7usYw2e926z4XT_hvHTKOQbDGmmLMCQg@mail.gmail.com>
	<CAPTjJmrN_FHKUhq37xUnMCu+P7N6j5Pde8P8qMpDXpovTMp77w@mail.gmail.com>
Message-ID: <CALwzidnAAQrLGWwkZf9O7w6V1CY-5jh6KFLJdP7eY9R3aOy7kA@mail.gmail.com>

On Sun, May 26, 2013 at 4:16 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Mon, May 27, 2013 at 5:35 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>> I'm pretty sure that CPython uses the GIL regardless of platform.  And
>> yes you can have multiple OS-level threads, but because of the GIL
>> only one will actually be running at a time.  Other possibilities
>> include:
>
> 6) It's spinning in a function that has released the GIL. Python
> threads can certainly execute concurrently; they just can't be
> manipulating Python objects. Most of the I/O functions will release
> the GIL before doing a potentially-blocking operation, and some
> CPU-heavy functions can do the same (I'm given to understand that
> numpy does this) - just depends on having a long job that involves no
> refcounted objects.

7) Since the program being tested does basically nothing except start
and exit threads, the extra 40% probably represents the overhead of
all that starting and stopping, which would be done outside the GIL.


From ian.g.kelly at gmail.com  Mon May 27 03:04:26 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 27 May 2013 01:04:26 -0600
Subject: Solving the problem of mutual recursion
In-Reply-To: <CALwzidnAAQrLGWwkZf9O7w6V1CY-5jh6KFLJdP7eY9R3aOy7kA@mail.gmail.com>
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
	<mailman.2185.1369591777.3114.python-list@python.org>
	<074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
	<CALwzidkUtWZvVvdKhU7usYw2e926z4XT_hvHTKOQbDGmmLMCQg@mail.gmail.com>
	<CAPTjJmrN_FHKUhq37xUnMCu+P7N6j5Pde8P8qMpDXpovTMp77w@mail.gmail.com>
	<CALwzidnAAQrLGWwkZf9O7w6V1CY-5jh6KFLJdP7eY9R3aOy7kA@mail.gmail.com>
Message-ID: <CALwzidnD+sKX2FLzGnPdwiAb9vARWa51fdtzpb+nNQndwKniQA@mail.gmail.com>

On Mon, May 27, 2013 at 12:19 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> 7) Since the program being tested does basically nothing except start
> and exit threads, the extra 40% probably represents the overhead of
> all that starting and stopping, which would be done outside the GIL.

To test this, I tried running the script in Python 2.7 in Linux with
the print statements removed and verified that it was using about 135%
of the CPU.  However, top also told me that only about 95% of that was
user processes; the other 40% was kernel usage.  The 40% doesn't seem
to be threading overhead though, because I tried adding large xrange
loops to slow down the thread creation process and it had no effect on
the stats.

Then I tried running the same program in Python 3.2, and I got the
more expected 100% CPU usage with minimal kernel time.  So I'm
thinking now that the extra 40% may actually be overhead induced by
the GIL.  If that's the case then wow, the old GIL really did suck.


From peter.h.m.brooks at gmail.com  Mon May 27 00:36:39 2013
From: peter.h.m.brooks at gmail.com (Peter Brooks)
Date: Sun, 26 May 2013 21:36:39 -0700 (PDT)
Subject: Solving the problem of mutual recursion
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
	<mailman.2185.1369591777.3114.python-list@python.org>
	<074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
	<CALwzidkUtWZvVvdKhU7usYw2e926z4XT_hvHTKOQbDGmmLMCQg@mail.gmail.com>
	<mailman.2209.1369606596.3114.python-list@python.org>
Message-ID: <9890fd93-fd9b-4865-a01e-4cd1d558d5fc@w15g2000vbn.googlegroups.com>

On May 27, 12:16?am, Chris Angelico <ros... at gmail.com> wrote:
> On Mon, May 27, 2013 at 5:35 AM, Ian Kelly <ian.g.ke... at gmail.com> wrote:
> > I'm pretty sure that CPython uses the GIL regardless of platform. ?And
> > yes you can have multiple OS-level threads, but because of the GIL
> > only one will actually be running at a time. ?Other possibilities
> > include:
>
> 6) It's spinning in a function that has released the GIL. Python
> threads can certainly execute concurrently; they just can't be
> manipulating Python objects. Most of the I/O functions will release
> the GIL before doing a potentially-blocking operation, and some
> CPU-heavy functions can do the same (I'm given to understand that
> numpy does this) - just depends on having a long job that involves no
> refcounted objects.
>
This makes complete sense - any atomic action should be atomic, so two
threads can't be doing it at the same time. They can be doing anything
else though.

If two threads create a new object at the same time, for example,
there's potentially the problem that they'll get the same space, so
the object will be owned by both. To prevent this, the new object call
should be run in only one thread.

If you have two objects running their methods on their own local
variables, then there's no potential for conflict, so there's no need
for them to be blocked.

This is an interesting subject.. There's nothing wrong with the tool
I'm using to report threads - 'Activity Monitor' is the standard
process monitor. It counts cores as 'CPUs', which seems perfectly
reasonable to me. As I said, other Unixes, such as HP-UX, do the same
thing.

I'm not quite sure of the best way to examine the exact behaviour.
Since the blocking works at the level of atomic operations, it's
difficult to detect - a call to an atomic operation may block all
other threads, but any snapshot of the number of active threads won't
be running at this time, so will only report when there are multiple
threads active.


From ian.g.kelly at gmail.com  Mon May 27 02:07:23 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 27 May 2013 00:07:23 -0600
Subject: Solving the problem of mutual recursion
In-Reply-To: <9890fd93-fd9b-4865-a01e-4cd1d558d5fc@w15g2000vbn.googlegroups.com>
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
	<mailman.2185.1369591777.3114.python-list@python.org>
	<074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
	<CALwzidkUtWZvVvdKhU7usYw2e926z4XT_hvHTKOQbDGmmLMCQg@mail.gmail.com>
	<mailman.2209.1369606596.3114.python-list@python.org>
	<9890fd93-fd9b-4865-a01e-4cd1d558d5fc@w15g2000vbn.googlegroups.com>
Message-ID: <CALwzidnz1Fnrg1W3AtF+WLk7hX88N=4A4_NK4dKV1UfWZhYMig@mail.gmail.com>

On Sun, May 26, 2013 at 10:36 PM, Peter Brooks
<peter.h.m.brooks at gmail.com> wrote:
> This makes complete sense - any atomic action should be atomic, so two
> threads can't be doing it at the same time. They can be doing anything
> else though.
>
> If two threads create a new object at the same time, for example,
> there's potentially the problem that they'll get the same space, so
> the object will be owned by both. To prevent this, the new object call
> should be run in only one thread.
>
> If you have two objects running their methods on their own local
> variables, then there's no potential for conflict, so there's no need
> for them to be blocked.

That's not the way it works.  The CPython interpreter always runs with
the GIL held; the alternative would be to have individual mutex locks
on every Python object, which is expensive for performance due to the
reference counting mechanism.  Python functions can't release the GIL.
 C functions that are called from the interpreter *can* release the
GIL to allow concurrency, but are only permitted to do so as long as
they're not working with Python objects, e.g. waiting on I/O or
performing a long calculation on C data.

There are some more detailed slides on how the GIL works at:

http://www.dabeaz.com/python/UnderstandingGIL.pdf

Note that the description in Part 1 describes how the GIL worked prior
to Python 3.2.  The new GIL is described in Part 4, but the basic
underlying concept is the same.

> This is an interesting subject.. There's nothing wrong with the tool
> I'm using to report threads - 'Activity Monitor' is the standard
> process monitor. It counts cores as 'CPUs', which seems perfectly
> reasonable to me. As I said, other Unixes, such as HP-UX, do the same
> thing.

I have no problem with that.  It's also the default in Linux, where I
believe it is called "IRIX mode" (as opposed to "Solaris mode", where
the difference is just a factor equal to the number of cores).  What I
was questioning was whether the actual number being reported was
correct.  If it's the standard tool for the OS, then it probably is.


From rosuav at gmail.com  Mon May 27 03:37:21 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 17:37:21 +1000
Subject: Solving the problem of mutual recursion
In-Reply-To: <CALwzidnz1Fnrg1W3AtF+WLk7hX88N=4A4_NK4dKV1UfWZhYMig@mail.gmail.com>
References: <55942e65-e4a5-45fc-b2fc-ceb4020959dd@k4g2000vba.googlegroups.com>
	<qota9nhu6ag.fsf@ruuvi.it.helsinki.fi>
	<d54dff54-73cc-4b90-8a85-bafd5118489f@cl9g2000vbb.googlegroups.com>
	<mailman.2185.1369591777.3114.python-list@python.org>
	<074eac8a-1bc4-4fe0-afa9-1f52405f81d5@k3g2000vbn.googlegroups.com>
	<CALwzidkUtWZvVvdKhU7usYw2e926z4XT_hvHTKOQbDGmmLMCQg@mail.gmail.com>
	<mailman.2209.1369606596.3114.python-list@python.org>
	<9890fd93-fd9b-4865-a01e-4cd1d558d5fc@w15g2000vbn.googlegroups.com>
	<CALwzidnz1Fnrg1W3AtF+WLk7hX88N=4A4_NK4dKV1UfWZhYMig@mail.gmail.com>
Message-ID: <CAPTjJmr2_n01mtRzLyCCH_+MEAkCiLOBpcwpCcYMrJ9Af2oJ5Q@mail.gmail.com>

On Mon, May 27, 2013 at 4:07 PM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Sun, May 26, 2013 at 10:36 PM, Peter Brooks
> <peter.h.m.brooks at gmail.com> wrote:
>> This makes complete sense - any atomic action should be atomic, so two
>> threads can't be doing it at the same time. They can be doing anything
>> else though.
>>
>> If two threads create a new object at the same time, for example,
>> there's potentially the problem that they'll get the same space, so
>> the object will be owned by both. To prevent this, the new object call
>> should be run in only one thread.
>>
>> If you have two objects running their methods on their own local
>> variables, then there's no potential for conflict, so there's no need
>> for them to be blocked.
>
> That's not the way it works. [snip details]

You're actually both saying the same thing, except that Peter went for
finer granularity than Ian and CPython did. CPython figures that, with
a refcounted heap, there's not a lot of point having separate mutex
locks for different operations. Other language interpreters have made
other choices. But Peter's analysis is still correct; it's just that
guarding it is simplified down to a binary state: either you have the
GIL, or you don't.

ChrisA


From mok-kong.shen at t-online.de  Sun May 26 08:02:39 2013
From: mok-kong.shen at t-online.de (Mok-Kong Shen)
Date: Sun, 26 May 2013 14:02:39 +0200
Subject: Output from to_bytes
Message-ID: <knstkh$74a$1@news.albasani.net>

I don't understand why with the code:

    for k in range(8,12,1):
      print(k.to_bytes(2,byteorder='big'))

one gets the following output:

    b'\x00\x08'
    b'\x00\t'
    b'\x00\n'
    b'\x00\x0b'

I mean the 2nd and 3rd should be b'\x00\x09' and b'x00\x0a'.
Anyway, how could I get the output in the forms I want?

Thanks in advance.

M. K. Shen




From rosuav at gmail.com  Sun May 26 09:26:33 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 23:26:33 +1000
Subject: Output from to_bytes
In-Reply-To: <knstkh$74a$1@news.albasani.net>
References: <knstkh$74a$1@news.albasani.net>
Message-ID: <CAPTjJmqRYMstS7p+SNQ+tG5f=m1rzWZdTZt8y32ObKp6ZDLAAg@mail.gmail.com>

On Sun, May 26, 2013 at 10:02 PM, Mok-Kong Shen
<mok-kong.shen at t-online.de> wrote:
> I don't understand why with the code:
>
>    for k in range(8,12,1):
>      print(k.to_bytes(2,byteorder='big'))
>
> one gets the following output:
>
>    b'\x00\x08'
>    b'\x00\t'
>    b'\x00\n'
>    b'\x00\x0b'
>
> I mean the 2nd and 3rd should be b'\x00\x09' and b'x00\x0a'.
> Anyway, how could I get the output in the forms I want?

They are. If you compare them, you'll find they're identical:

>>> b'\x00\t' == b'\x00\x09'
True
>>> b'\x00\n' == b'\x00\x0a'
True

It's just a representation issue. The repr() of a bytes tries to go
for the shorter representation \n rather than the more verbose \x0a.
(Though I'm not sure why it doesn't also shorten \x00 to \0 - maybe
the \0 notation isn't deemed Pythonic, even though it does work just
fine.) So what you want is a more fixed representation.

What you may find useful here is that iterating over the bytes object
produces integers:

>>> list(b'\0\t')
[0, 9]

So you might be able to do something like this:

>>> print(''.join(('\\x%02x'%x for x in b'\0\t')))
\x00\x09

Or, in your whole loop:

>>> for k in range(8,12,1):
	print(''.join(('\\x%02x'%x for x in k.to_bytes(2,byteorder='big'))))

\x00\x08
\x00\x09
\x00\x0a
\x00\x0b

Does that help?

ChrisA


From tjreedy at udel.edu  Sun May 26 16:45:50 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 26 May 2013 16:45:50 -0400
Subject: Output from to_bytes
In-Reply-To: <knstkh$74a$1@news.albasani.net>
References: <knstkh$74a$1@news.albasani.net>
Message-ID: <knts9h$5ka$1@ger.gmane.org>

On 5/26/2013 8:02 AM, Mok-Kong Shen wrote:
>     for k in range(8,12,1):
>       print(k.to_bytes(2,byteorder='big'))

http://bugs.python.org/issue9951
http://bugs.python.org/issue3532

import binascii as ba
for k in range(8,12,1):
     print(ba.hexlify(k.to_bytes(2,byteorder='big')))
 >>>
b'0008'
b'0009'
b'000a'
b'000b'




From invalid at invalid.invalid  Tue May 28 11:35:19 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 15:35:19 +0000 (UTC)
Subject: Output from to_bytes
References: <knstkh$74a$1@news.albasani.net>
Message-ID: <ko2irn$9oh$1@reader1.panix.com>

On 2013-05-26, Mok-Kong Shen <mok-kong.shen at t-online.de> wrote:
> I don't understand why with the code:
>
>     for k in range(8,12,1):
>       print(k.to_bytes(2,byteorder='big'))
>
> one gets the following output:
>
>     b'\x00\x08'
>     b'\x00\t'
>     b'\x00\n'
>     b'\x00\x0b'
>
> I mean the 2nd and 3rd should be b'\x00\x09' and b'x00\x0a'.
> Anyway, how could I get the output in the forms I want?

Well, it would help if you told us what output form you want.

-- 
Grant Edwards               grant.b.edwards        Yow! I'm gliding over a
                                  at               NUCLEAR WASTE DUMP near
                              gmail.com            ATLANTA, Georgia!!


From nikos.gr33k at gmail.com  Sun May 26 12:36:29 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 09:36:29 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
Message-ID: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>

This is the code that although correct becaus it works with englisg(standARD ASCII letters) it wont with Greek:

if( log ):
	name = log
	# print specific client header info
	cur.execute('''SELECT hits, money FROM clients WHERE name = %s''', (name,) )
	data = cur.fetchone()
=======================

The following is the live output of: tail -F /usr/local/apache/logs/error_log &


[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] Error in sys.excepthook:, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] UnicodeEncodeError: 'ascii' codec can't encode characters in position 2050-2056: ordinal not in range(128), referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] , referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] Original exception was:, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] Traceback (most recent call last):, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11]   File "pelatologio.py", line 122, in <module>, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11]     cur.execute('''SELECT hits, money FROM clients WHERE name = %s''', (name,) ), referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11]   File "/opt/python3/lib/python3.3/site-packages/pymysql/cursors.py", line 108, in execute, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11]     query = query.encode(charset), referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] UnicodeEncodeError: 'latin-1' codec can't encode characters in position 46-52: ordinal not in range(256), referer: http://superhost.gr/cgi-bin/pelatologio.py


I can udnerstand that this is an encoding issue but i dont knwo how to fix this.
please help.

The search works only for english letters as expected but my cleints have Greek name and surnames.


From nikos.gr33k at gmail.com  Sun May 26 14:20:19 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 11:20:19 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
Message-ID: <435277a8-2821-4927-9c99-548d75600f9a@googlegroups.com>

Any idea how to correct this encoding issue?


From tjreedy at udel.edu  Sun May 26 16:53:56 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 26 May 2013 16:53:56 -0400
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
Message-ID: <kntson$al1$1@ger.gmane.org>

On 5/26/2013 12:36 PM, ????? ???33? wrote:
> This is the code that although correct becaus it works with englisg(standARD ASCII letters) it wont with Greek:
>
> if( log ):
> 	name = log
> 	# print specific client header info
> 	cur.execute('''SELECT hits, money FROM clients WHERE name = %s''', (name,) )
> 	data = cur.fetchone()
> =======================
>
> The following is the live output of: tail -F /usr/local/apache/logs/error_log &
>
>
> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] Error in sys.excepthook:, referer: http://superhost.gr/cgi-bin/pelatologio.py
> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] UnicodeEncodeError: 'ascii' codec can't encode characters in position 2050-2056: ordinal not in range(128), referer: http://superhost.gr/cgi-bin/pelatologio.py
> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] , referer: http://superhost.gr/cgi-bin/pelatologio.py
> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] Original exception was:, referer: http://superhost.gr/cgi-bin/pelatologio.py
> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] Traceback (most recent call last):, referer: http://superhost.gr/cgi-bin/pelatologio.py
> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11]   File "pelatologio.py", line 122, in <module>, referer: http://superhost.gr/cgi-bin/pelatologio.py
> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11]     cur.execute('''SELECT hits, money FROM clients WHERE name = %s''', (name,) ), referer: http://superhost.gr/cgi-bin/pelatologio.py

> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11]   File "/opt/python3/lib/python3.3/site-packages/pymysql/cursors.py", line 108, in execute, referer: http://superhost.gr/cgi-bin/pelatologio.py
> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11]     query = query.encode(charset), referer: http://superhost.gr/cgi-bin/pelatologio.py
> [Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] UnicodeEncodeError: 'latin-1' codec can't encode characters in position 46-52: ordinal not in range(256), referer: http://superhost.gr/cgi-bin/pelatologio.py

This appears to be an issue with your mysql database and how you set it 
up.. It is using charset='latin-1' whereas you need it to consistently 
use charset='utf8' both for storing strings and for retrieval. Check the 
mysql manual or ask on a mysql list for how to do that. I have no idea 
so don't ask me, or send mail to my emall address.




From nikos.gr33k at gmail.com  Sun May 26 17:26:34 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 14:26:34 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2199.1369601640.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<mailman.2199.1369601640.3114.python-list@python.org>
Message-ID: <afb5c351-3ffe-49cf-bc3e-aca5107ad6f4@googlegroups.com>

No thi is not a mysql issue becaus ei have this line above for storing and retrieval form database.

con = pymysql.connect( db = 'metrites', host = 'localhost', user = 'me', passwd = 'somepass', init_command='SET NAMES UTF8' )


From rosuav at gmail.com  Sun May 26 17:44:57 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 07:44:57 +1000
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <afb5c351-3ffe-49cf-bc3e-aca5107ad6f4@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<mailman.2199.1369601640.3114.python-list@python.org>
	<afb5c351-3ffe-49cf-bc3e-aca5107ad6f4@googlegroups.com>
Message-ID: <CAPTjJmqEp53oq8nqxA3eud+rmH29KWmL3kywS7+KC3nmniXXWw@mail.gmail.com>

On Mon, May 27, 2013 at 7:26 AM, ????? ???33? <nikos.gr33k at gmail.com> wrote:
> No thi is not a mysql issue becaus ei have this line above for storing and retrieval form database.
>
> con = pymysql.connect( db = 'metrites', host = 'localhost', user = 'me', passwd = 'somepass', init_command='SET NAMES UTF8' )

Research MySQL and UTF-8, then see how your command is actually
flawed. Then research ESR and asking questions the smart way, and see
how your post is also flawed.

ChrisA


From breamoreboy at yahoo.co.uk  Sun May 26 18:21:25 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 23:21:25 +0100
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <afb5c351-3ffe-49cf-bc3e-aca5107ad6f4@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<mailman.2199.1369601640.3114.python-list@python.org>
	<afb5c351-3ffe-49cf-bc3e-aca5107ad6f4@googlegroups.com>
Message-ID: <knu1sk$egq$3@ger.gmane.org>

On 26/05/2013 22:26, ????? ???33? wrote:
> No thi is not a mysql issue becaus ei have this line above for storing and retrieval form database.
>
> con = pymysql.connect( db = 'metrites', host = 'localhost', user = 'me', passwd = 'somepass', init_command='SET NAMES UTF8' )
>

No wonder the Greek economy is so screwed up.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From carlosnepomuceno at outlook.com  Sun May 26 18:31:57 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 27 May 2013 01:31:57 +0300
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <knu1sk$egq$3@ger.gmane.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>,
	<mailman.2199.1369601640.3114.python-list@python.org>,
	<afb5c351-3ffe-49cf-bc3e-aca5107ad6f4@googlegroups.com>,
	<knu1sk$egq$3@ger.gmane.org>
Message-ID: <BLU176-W25A34062E1E8969DE7840BD7950@phx.gbl>

----------------------------------------
> To: python-list at python.org
> From: breamoreboy at yahoo.co.uk
[...]
> No wonder the Greek economy is so screwed up.
>
> --
> If you're using GoogleCrap? please read this
> http://wiki.python.org/moin/GoogleGroupsPython.
>
> Mark Lawrence

LOL LOL LOL LOL LOL LOL HAHAHAHAHA!!!! 		 	   		  

From rosuav at gmail.com  Sun May 26 18:32:12 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 08:32:12 +1000
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <knu1sk$egq$3@ger.gmane.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<mailman.2199.1369601640.3114.python-list@python.org>
	<afb5c351-3ffe-49cf-bc3e-aca5107ad6f4@googlegroups.com>
	<knu1sk$egq$3@ger.gmane.org>
Message-ID: <CAPTjJmrRs2v925yNg+gYJypFSjsu1rw7W40uTo3jgezt8G7ZvQ@mail.gmail.com>

On Mon, May 27, 2013 at 8:21 AM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 26/05/2013 22:26, ????? ???33? wrote:
>>
>> No thi is not a mysql issue becaus ei have this line above for storing and
>> retrieval form database.
>>
>> con = pymysql.connect( db = 'metrites', host = 'localhost', user = 'me',
>> passwd = 'somepass', init_command='SET NAMES UTF8' )
>>
>
> No wonder the Greek economy is so screwed up.

Do you think the Greek economy would be improved by Python coming with
PostgreSQL bindings? That'd push a lot of people onto a better
database engine than MySQL.

ChrisA


From breamoreboy at yahoo.co.uk  Sun May 26 18:51:41 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 23:51:41 +0100
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <CAPTjJmrRs2v925yNg+gYJypFSjsu1rw7W40uTo3jgezt8G7ZvQ@mail.gmail.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<mailman.2199.1369601640.3114.python-list@python.org>
	<afb5c351-3ffe-49cf-bc3e-aca5107ad6f4@googlegroups.com>
	<knu1sk$egq$3@ger.gmane.org>
	<CAPTjJmrRs2v925yNg+gYJypFSjsu1rw7W40uTo3jgezt8G7ZvQ@mail.gmail.com>
Message-ID: <knu3lc$6ph$1@ger.gmane.org>

On 26/05/2013 23:32, Chris Angelico wrote:
> On Mon, May 27, 2013 at 8:21 AM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>> On 26/05/2013 22:26, ????? ???33? wrote:
>>>
>>> No thi is not a mysql issue becaus ei have this line above for storing and
>>> retrieval form database.
>>>
>>> con = pymysql.connect( db = 'metrites', host = 'localhost', user = 'me',
>>> passwd = 'somepass', init_command='SET NAMES UTF8' )
>>>
>>
>> No wonder the Greek economy is so screwed up.
>
> Do you think the Greek economy would be improved by Python coming with
> PostgreSQL bindings? That'd push a lot of people onto a better
> database engine than MySQL.
>
> ChrisA
>

Even the best economies would be improved by Python coming with 
PostgreSQL bindings, but if and only if the user knew how to use them :)

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From timr at probo.com  Sun May 26 22:01:17 2013
From: timr at probo.com (Tim Roberts)
Date: Sun, 26 May 2013 19:01:17 -0700
Subject: Encodign  issue in Python 3.3.1 (once again)
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
Message-ID: <69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>

????? ???33? <nikos.gr33k at gmail.com> wrote:
>
>This is the code that although correct becaus it works with englisg(standARD ASCII letters) it wont with Greek:
>...
>if( log ):
>	name = log
>	# print specific client header info
>	cur.execute('''SELECT hits, money FROM clients WHERE name = %s''', (name,) )
>	data = cur.fetchone()
>=======================
>
>The following is the live output of: tail -F /usr/local/apache/logs/error_log &
>...
>   File "/opt/python3/lib/python3.3/site-packages/pymysql/cursors.py", line 108, in execute, referer: http://superhost.gr/cgi-bin/pelatologio.py
>     query = query.encode(charset), referer: http://superhost.gr/cgi-bin/pelatologio.py
> UnicodeEncodeError: 'latin-1' codec can't encode characters in position 46-52: ordinal not in range(256), referer: http://superhost.gr/cgi-bin/pelatologio.py
>
>I can udnerstand that this is an encoding issue but i dont knwo how to fix this.
>please help.

While the other responders have a good laugh at your expense, let me
actually point you toward a solution.

The traceback line I left above is the key.  It shows that the pymysql
module is trying to encode your Unicode string into an 8-bit character set
in order to send it to the MySQL server.  It is THAT conversion that
failed; this has nothing to do with the server (yet).

So, why did it choose 'latin-1'?  Because that's the default character set
for pymysql.  You could have learned this yourself -- you have the full
source code for pymysql on your machine.

You can override the default character set:

    con = pymysql.connect( db = 'metrites', host = 'localhost', user =
'me', passwd = 'somepass', charset='utf-8', init_command='SET NAMES UTF8' )
-- 
Tim Roberts, timr at probo.com
Providenza & Boekelheide, Inc.


From nikos.gr33k at gmail.com  Mon May 27 01:06:22 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Sun, 26 May 2013 22:06:22 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
Message-ID: <9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>

But iu have it set up for 'utf-8' as seen in this statement.

con = pymysql.connect( db = 'metrites', host = 'localhost', user = 
'me', passwd = 'somepass', charset='utf-8', init_command='SET NAMES UTF8' ) 

Yoiu mean i shoudl chnag eit to greek isoo= (iso-8859-7)

but then i store english names and greek names as well, so it has to be a utf-8.


From nikos.gr33k at gmail.com  Mon May 27 10:16:42 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Mon, 27 May 2013 07:16:42 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
Message-ID: <d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>

I cant solve this plz help!


From breamoreboy at yahoo.co.uk  Mon May 27 10:45:25 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 27 May 2013 15:45:25 +0100
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>
Message-ID: <knvrhi$l5a$1@ger.gmane.org>

On 27/05/2013 15:16, ????? ???33? wrote:
> I cant solve this plz help!
>

Sure, all you need do is get your cheque book out.  Also have you ever 
heard the expression "patience is a virtue"?

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From nikos.gr33k at gmail.com  Mon May 27 11:37:52 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Mon, 27 May 2013 08:37:52 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2252.1369665933.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>
	<mailman.2252.1369665933.3114.python-list@python.org>
Message-ID: <529f6d18-65a3-437a-944c-890bbacd9212@googlegroups.com>

?? ???????, 27 ????? 2013 5:45:25 ?.?. UTC+3, ? ??????? Mark Lawrence ??????:

> Sure, all you need do is get your cheque book out.  Also have you ever 
> heard the expression "patience is a virtue"?

Well, if i'am gonna pay someone and i will at some point because i want my script to be also re-written using a web framework(Django) it will certainly be someone that can actually provide a so;lution instead of aksing for cheque books.



From rosuav at gmail.com  Mon May 27 11:52:32 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 28 May 2013 01:52:32 +1000
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <529f6d18-65a3-437a-944c-890bbacd9212@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>
	<mailman.2252.1369665933.3114.python-list@python.org>
	<529f6d18-65a3-437a-944c-890bbacd9212@googlegroups.com>
Message-ID: <CAPTjJmpnRYQxT_K3U1CD7JGa9jHivGu6pStONkAp4YhbC=9MyA@mail.gmail.com>

On Tue, May 28, 2013 at 1:37 AM, ????? ???33? <nikos.gr33k at gmail.com> wrote:
> ?? ???????, 27 ????? 2013 5:45:25 ?.?. UTC+3, ? ??????? Mark Lawrence ??????:
>
>> Sure, all you need do is get your cheque book out.  Also have you ever
>> heard the expression "patience is a virtue"?
>
> Well, if i'am gonna pay someone and i will at some point because i want my script to be also re-written using a web framework(Django) it will certainly be someone that can actually provide a so;lution instead of aksing for cheque books.

So you want to pay someone who won't ask for money?

It may be sordid, but you're going to have to discuss money at some
point if you're serious about paying someone.

Oh, and you may want to hire a typist, too. At the moment, your posts
make you appear not to care about the job.

ChrisA


From nikos.gr33k at gmail.com  Mon May 27 12:56:37 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Mon, 27 May 2013 09:56:37 -0700 (PDT)
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2254.1369670419.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>
	<mailman.2252.1369665933.3114.python-list@python.org>
	<529f6d18-65a3-437a-944c-890bbacd9212@googlegroups.com>
	<mailman.2254.1369670419.3114.python-list@python.org>
Message-ID: <9d0cfcdd-0644-4d15-8165-5452c19e57a3@googlegroups.com>

?? ???????, 27 ????? 2013 6:52:32 ?.?. UTC+3, ? ??????? Chris Angelico ??????:

> So you want to pay someone who won't ask for money?
> It may be sordid, but you're going to have to discuss money at some
> point if you're serious about paying someone.
> Oh, and you may want to hire a typist, too. At the moment, your posts 
> make you appear not to care about the job.

I always make typos when iam typing fast.
And yes at some point i will pay a person from this groups to alter my scripts to utilize web frameworks.
To answer your question yes, i will be paying a person from this group that have been providing me solutions to previous questions without laughing at my expense and without requiring money frome to do so.
I have 2-3 people in mind.
I have managed to turn ALL my python 2.6 scripts to python 3.3.1 except this last problem i have to deal with.

http://superhost.gr/?page=pelatologio.py works partiall but only displays info when i click on person names in English, not with Greek names.

If someone want to give me a hand with this, please do.


From rosuav at gmail.com  Mon May 27 18:18:06 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 28 May 2013 08:18:06 +1000
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <9d0cfcdd-0644-4d15-8165-5452c19e57a3@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>
	<mailman.2252.1369665933.3114.python-list@python.org>
	<529f6d18-65a3-437a-944c-890bbacd9212@googlegroups.com>
	<mailman.2254.1369670419.3114.python-list@python.org>
	<9d0cfcdd-0644-4d15-8165-5452c19e57a3@googlegroups.com>
Message-ID: <CAPTjJmqYLiZfxLO4sb2RruSLj1K6HEnK-W57TC2ULvVq5siH+Q@mail.gmail.com>

On Tue, May 28, 2013 at 2:56 AM, ????? ???33? <nikos.gr33k at gmail.com> wrote:
> ?? ???????, 27 ????? 2013 6:52:32 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
>
>> Oh, and you may want to hire a typist, too. At the moment, your posts
>> make you appear not to care about the job.
>
> I always make typos when iam typing fast.

Yes, but then you don't go back and correct them before hitting Send,
which is what makes you appear to care very little. Typos in real-time
chat are understandable (though even on MUDs, most people tend to
broadcast less typos than your posts have, because even there there's
time to edit before hitting Enter), but with email, it's very easy to
spend 60 seconds glancing over your post before you send it. You're
using gmail, so chances are all you need to do is use a web browser
with a spellchecker and you'll catch all of the typos; I use Google
Chrome, and it has the now-prevalent red squiggly lines under all
suspected errors. (It's not perfect, of course; quite a few
correctly-spelled words are mistakenly flagged. But it's still pretty
effective at catching typos.)

You're effectively asking people to put in a few minutes' work,
sometimes quite a few minutes, to help you. Is it too much to hope
that you'll spend one more minute on your posts?

This is something that's utterly trivial, yet a window to your mind.
It's like boarding an airliner and finding coffee stains on the
flip-down trays - the plane flies just fine with those stains, yet the
impression they give is that the crew don't care about engine
maintenance either.

ChrisA


From carlosnepomuceno at outlook.com  Mon May 27 21:00:19 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 01:00:19 -0000
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <CAPTjJmqYLiZfxLO4sb2RruSLj1K6HEnK-W57TC2ULvVq5siH+Q@mail.gmail.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>,
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>,
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>,
	<d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>,
	<mailman.2252.1369665933.3114.python-list@python.org>,
	<529f6d18-65a3-437a-944c-890bbacd9212@googlegroups.com>,
	<mailman.2254.1369670419.3114.python-list@python.org>,
	<9d0cfcdd-0644-4d15-8165-5452c19e57a3@googlegroups.com>,
	<CAPTjJmqYLiZfxLO4sb2RruSLj1K6HEnK-W57TC2ULvVq5siH+Q@mail.gmail.com>
Message-ID: <BLU176-W42F61EFC466B438BA8179DD7970@phx.gbl>

----------------------------------------
> Date: Tue, 28 May 2013 08:18:06 +1000
> Subject: Re: Encodign issue in Python 3.3.1 (once again)
> From: rosuav at gmail.com
> To: python-list at python.org
[...]
>
> This is something that's utterly trivial, yet a window to your mind.
> It's like boarding an airliner and finding coffee stains on the
> flip-down trays - the plane flies just fine with those stains, yet the
> impression they give is that the crew don't care about engine
> maintenance either.
>
> ChrisA


Stain Is Too Damn High!!! lol

That's my party man!!! :) 		 	   		  

From nikos.gr33k at gmail.com  Tue May 28 01:55:52 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Mon, 27 May 2013 22:55:52 -0700 (PDT)
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2264.1369693095.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>
	<mailman.2252.1369665933.3114.python-list@python.org>
	<529f6d18-65a3-437a-944c-890bbacd9212@googlegroups.com>
	<mailman.2254.1369670419.3114.python-list@python.org>
	<9d0cfcdd-0644-4d15-8165-5452c19e57a3@googlegroups.com>
	<mailman.2264.1369693095.3114.python-list@python.org>
Message-ID: <8d7651bd-a4f7-4f8f-bba8-99f5aee6f6b4@googlegroups.com>

?? ?????, 28 ????? 2013 1:18:06 ?.?. UTC+3, ? ??????? Chris Angelico ??????:

> You're effectively asking people to put in a few minutes' work, 
> sometimes quite a few minutes, to help you. Is it too much to hope
> that you'll spend one more minute on your posts?

No it is not, you are right, i should be more careful when typing and spend some time to correct before i send my responses. I promise i will not overlook this as well as the blank line google imposes.

As fo my initial question any comments-remarks?


From rustompmody at gmail.com  Tue May 28 07:56:57 2013
From: rustompmody at gmail.com (rusi)
Date: Tue, 28 May 2013 04:56:57 -0700 (PDT)
Subject: Encodign issue in Python 3.3.1 (once again)
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>
	<mailman.2252.1369665933.3114.python-list@python.org>
	<529f6d18-65a3-437a-944c-890bbacd9212@googlegroups.com>
	<mailman.2254.1369670419.3114.python-list@python.org>
	<9d0cfcdd-0644-4d15-8165-5452c19e57a3@googlegroups.com>
	<mailman.2264.1369693095.3114.python-list@python.org>
	<8d7651bd-a4f7-4f8f-bba8-99f5aee6f6b4@googlegroups.com>
Message-ID: <39469c94-ddef-4492-ab6f-db2a6c61db49@vy4g2000pbc.googlegroups.com>

On May 28, 10:55?am, ????? ???33? <nikos.gr... at gmail.com> wrote:
> ?? ?????, 28 ????? 2013 1:18:06 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
>
> > You're effectively asking people to put in a few minutes' work,
> > sometimes quite a few minutes, to help you. Is it too much to hope
> > that you'll spend one more minute on your posts?
>
> No it is not, you are right, i should be more careful when typing and spend some time to correct before i send my responses. I promise i will not overlook this as well as the blank line google imposes.
>
> As fo my initial question any comments-remarks?

You say you should be more careful to correct your typing and
'promise' to not overlook this.
Your next line has a 'fo' instead of a 'for'


From danielgagliardiramos at gmail.com  Tue May 28 09:49:59 2013
From: danielgagliardiramos at gmail.com (Daniel Gagliardi Ramos)
Date: Tue, 28 May 2013 10:49:59 -0300
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <39469c94-ddef-4492-ab6f-db2a6c61db49@vy4g2000pbc.googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<d852ad8c-3be5-4659-a005-ac30f2be3eb8@googlegroups.com>
	<mailman.2252.1369665933.3114.python-list@python.org>
	<529f6d18-65a3-437a-944c-890bbacd9212@googlegroups.com>
	<mailman.2254.1369670419.3114.python-list@python.org>
	<9d0cfcdd-0644-4d15-8165-5452c19e57a3@googlegroups.com>
	<mailman.2264.1369693095.3114.python-list@python.org>
	<8d7651bd-a4f7-4f8f-bba8-99f5aee6f6b4@googlegroups.com>
	<39469c94-ddef-4492-ab6f-db2a6c61db49@vy4g2000pbc.googlegroups.com>
Message-ID: <CAGpAtSFWTExJeL=0DXhu1W=ZyxHgoNFKnqXp_Z4tsvDUrcbzCQ@mail.gmail.com>

don't ya have something intelligent to say motherfucker?


2013/5/28 rusi <rustompmody at gmail.com>

> On May 28, 10:55 am, ????? ???33? <nikos.gr... at gmail.com> wrote:
> > ?? ?????, 28 ????? 2013 1:18:06 ?.?. UTC+3, ? ??????? Chris Angelico
> ??????:
> >
> > > You're effectively asking people to put in a few minutes' work,
> > > sometimes quite a few minutes, to help you. Is it too much to hope
> > > that you'll spend one more minute on your posts?
> >
> > No it is not, you are right, i should be more careful when typing and
> spend some time to correct before i send my responses. I promise i will not
> overlook this as well as the blank line google imposes.
> >
> > As fo my initial question any comments-remarks?
>
> You say you should be more careful to correct your typing and
> 'promise' to not overlook this.
> Your next line has a 'fo' instead of a 'for'
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From torriem at gmail.com  Mon May 27 10:42:56 2013
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 27 May 2013 08:42:56 -0600
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
Message-ID: <51A370F0.8090909@gmail.com>

On 05/26/2013 11:06 PM, ????? ???33? wrote:
> But iu have it set up for 'utf-8' as seen in this statement.
> 
> con = pymysql.connect( db = 'metrites', host = 'localhost', user = 
> 'me', passwd = 'somepass', charset='utf-8', init_command='SET NAMES UTF8' ) 

That might not help... see below.

> 
> Yoiu mean i shoudl chnag eit to greek isoo= (iso-8859-7)
> but then i store english names and greek names as well, so it has to be a utf-8.

Right.  UTF-8 is the encoding you want.

I think your problem is that when the MySQL database was created, it was
not created using the UTF-8 mode, but rather latin-1 (despite your
init_command which has nothing to do with database creation).  You'll
want to recreate the database and make double sure you've selected the
right character set and collation:

http://dev.mysql.com/doc/refman/5.0/en/charset-applications.html

At least that should be your first step in debugging this problem.

If the database is indeed utf-8, then you can move on to debugging why
the python code is choosing latin-1 to encode your query string.

That's my two-cents for today.


From nikos.gr33k at gmail.com  Mon May 27 16:17:54 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Mon, 27 May 2013 13:17:54 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2251.1369665785.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
Message-ID: <f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>

I have checked the database through phpMyAdmin and it is indeed UTF-8.

I have no idea why python 3.3.1 chooses to work with latin-iso only....


From torriem at gmail.com  Tue May 28 10:34:25 2013
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 28 May 2013 08:34:25 -0600
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
Message-ID: <51A4C071.80609@gmail.com>

On 05/27/2013 02:17 PM, ????? ???33? wrote:
> I have checked the database through phpMyAdmin and it is indeed UTF-8.
> 
> I have no idea why python 3.3.1 chooses to work with latin-iso only....

It's not python that is doing this here...

If you look at the source code to pymysql, I'm sure you will identify
the problem.  In fact I'll even walk you through things.

The traceback you posted tells you what's going on and why, with
superfluous details removed for clarity:

File "/opt/python3/lib/python3.3/site-packages/pymysql/cursors.py", line
108, in execute:
     query = query.encode(charset)
UnicodeEncodeError: 'latin-1' codec can't encode characters in position
46-52: ordinal not in range(256)

So there we have it.  pymysql is actually explicitly calling .encode()
on a string and is using whatever character set is specified by the
local variable charset.  If you look in cursors.py at that line, and
then a few lines above, you will find that charset is assigned to
conn.charset.  This means that the charset is actually defined in the
connection object.  So go look at connections.py.  Sure enough, it shows
that charset is defined by default as "latin-1."  That's no good for
you.  So take a look at the __init__ method in connections.py.  In there
you should find the necessary keyword argument you need to use when
creating the mysql connection to make sure the charset is utf-8.



From nikos.gr33k at gmail.com  Tue May 28 12:00:18 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Tue, 28 May 2013 09:00:18 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2299.1369751680.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
Message-ID: <a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>

I do not know here to find connections.py Michael.

But i do not understand since iam suing the following 2 statements, why a unicode error remains.

#needed line, script does *not* work without it
sys.stdout = os.fdopen(1, 'w', encoding='utf-8')

# connect to database
con = pymysql.connect( db = 'pelatologio', host = 'localhost', user = 'myself', passwd = 'mypass', init_command='SET NAMES UTF8' )
cur = con.cursor()

Shall i chnage the connector form 'pymysql' => 'MySQLdb' ?


From python at mrabarnett.plus.com  Tue May 28 12:26:07 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 28 May 2013 17:26:07 +0100
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
Message-ID: <51A4DA9F.1040306@mrabarnett.plus.com>

On 28/05/2013 17:00, ????? ???33? wrote:
> I do not know here to find connections.py Michael.
>
> But i do not understand since iam suing the following 2 statements, why a unicode error remains.
>
> #needed line, script does *not* work without it
> sys.stdout = os.fdopen(1, 'w', encoding='utf-8')
>
> # connect to database
> con = pymysql.connect( db = 'pelatologio', host = 'localhost', user = 'myself', passwd = 'mypass', init_command='SET NAMES UTF8' )
> cur = con.cursor()
>
> Shall i chnage the connector form 'pymysql' => 'MySQLdb' ?
>
A quick look at the documentation tells me that the charset can be
specified in the 'connect' call, something like this:

con = pymysql.connect( db = 'pelatologio', host = 'localhost', user = 
'myself', passwd = 'mypass', init_command='SET NAMES UTF8', charset = 
'utf-8' )



From torriem at gmail.com  Tue May 28 12:40:09 2013
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 28 May 2013 10:40:09 -0600
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
Message-ID: <51A4DDE9.4010607@gmail.com>

On 05/28/2013 10:00 AM, ????? ???33? wrote:
> I do not know here to find connections.py Michael.

It's part of the pymysql package that you installed.  Look in there (the
traceback even shows you where the file is).  But you actually don't
even need to look at it on your server.  You can see the source code for
it here:

https://github.com/petehunt/PyMySQL/tree/master/pymysql

> But i do not understand since iam suing the following 2 statements,
> why a unicode error remains.

The traceback told you why the error is happening.  inside the pymysql
library, there is a call to .encode(charset) on your query string.  And
the default charset is latin-1.  You've got to work out a way to change
that and I've already told you exactly how to find out what you need to
do.

> #needed line, script does *not* work without it sys.stdout =
> os.fdopen(1, 'w', encoding='utf-8')
> 
> # connect to database con = pymysql.connect( db = 'pelatologio', host
> = 'localhost', user = 'myself', passwd = 'mypass', init_command='SET
> NAMES UTF8' ) cur = con.cursor()

HINT: this line ^^^^^^ is what you have to modify by passing in a
particular keyword argument that sets the character set (no it's not the
init_command one).  You will have to look at connections.py's __init__
declaration and you should see what you need to pass in.

Yes I could have saved myself a lot of time and typing by giving you the
answer, but that isn't going to help you.  On the other hand, if you
want the easy way out, paypal some money to me and I'll just give you
the answer instead of trying to give you the tools you need to debug
this issue.  The answers are all in the source code to pymysql, which is
open source so you can always read (either on your own server file
system or on the git repository).

> 
> Shall i chnage the connector form 'pymysql' => 'MySQLdb' ?

No.



From support at superhost.gr  Tue May 28 12:45:24 2013
From: support at superhost.gr (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Tue, 28 May 2013 09:45:24 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2305.1369759217.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
Message-ID: <d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>

con = pymysql.connect( db = 'pelatologio', host = 'localhost', user = 'blabla', passwd = 'blabla', init_command='SET NAMES UTF8', charset = 'utf-8' )

produces this "God knows what" error traceback....

 /home/nikos/public_html/cgi-bin/metrites.py in ()
    217                 template = htmldata + counter
    218         elif page.endswith('.py'):
=>  219                 htmldata = subprocess.check_output( '/home/nikos/public_html/cgi-bin/' + page )
    220                 template = htmldata.decode('utf-8').replace( 'Content-type: text/html; charset=utf-8', '' ) + counter
    221                 
htmldata undefined, subprocess = <module 'subprocess' from '/opt/python3/lib/python3.3/subprocess.py'>, subprocess.check_output = <function check_output>, page = 'pelatologio.py'
 /opt/python3/lib/python3.3/subprocess.py in check_output(timeout=None, *popenargs=('/home/nikos/public_html/cgi-bin/pelatologio.py',), **kwargs={})
    584         retcode = process.poll()
    585         if retcode:
=>  586             raise CalledProcessError(retcode, process.args, output=output)
    587     return output
    588 
global CalledProcessError = <class 'subprocess.CalledProcessError'>, retcode = 1, process = <subprocess.Popen object>, process.args = '/home/nikos/public_html/cgi-bin/pelatologio.py', output = b'<!--: spam\nContent-Type: text/html\n\n<body b...Type\' object has no attribute \'id\'\n\n-->\n\n'
CalledProcessError: Command '/home/nikos/public_html/cgi-bin/pelatologio.py' returned non-zero exit status 1 
      args = (1, '/home/nikos/public_html/cgi-bin/pelatologio.py') 
      cmd = '/home/nikos/public_html/cgi-bin/pelatologio.py' 
      output = b'<!--: spam\nContent-Type: text/html\n\n<body b...Type\' object has no attribute \'id\'\n\n-->\n\n' 
      returncode = 1 
      with_traceback = <built-in method with_traceback of CalledProcessError object>


From torriem at gmail.com  Tue May 28 13:17:05 2013
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 28 May 2013 11:17:05 -0600
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
Message-ID: <51A4E691.8050808@gmail.com>

On 05/28/2013 10:45 AM, ????? ???33? wrote:
> con = pymysql.connect( db = 'pelatologio', host = 'localhost', user = 'blabla', passwd = 'blabla', init_command='SET NAMES UTF8', charset = 'utf-8' )
> 
> produces this "God knows what" error traceback....

Hey at least your database code is now working.

>     /home/nikos/public_html/cgi-bin/metrites.py in ()
>     217                 template = htmldata + counter
>     218         elif page.endswith('.py'):
> =>  219                 htmldata = subprocess.check_output( '/home/nikos/public_html/cgi-bin/' + page )
>     220                 template = htmldata.decode('utf-8').replace( 'Content-type: text/html; charset=utf-8', '' ) + counter
>     221                 
> htmldata undefined, subprocess = <module 'subprocess' from '/opt/python3/lib/python3.3/subprocess.py'>, subprocess.check_output = <function check_output>, page = 'pelatologio.py'
>  /opt/python3/lib/python3.3/subprocess.py in check_output(timeout=None, *popenargs=('/home/nikos/public_html/cgi-bin/pelatologio.py',), **kwargs={})
>     584         retcode = process.poll()
>     585         if retcode:
> =>  586             raise CalledProcessError(retcode, process.args, output=output)
>     587     return output
>     588 
> global CalledProcessError = <class 'subprocess.CalledProcessError'>, retcode = 1, process = <subprocess.Popen object>, process.args = '/home/nikos/public_html/cgi-bin/pelatologio.py', output = b'<!--: spam\nContent-Type: text/html\n\n<body b...Type\' object has no attribute \'id\'\n\n-->\n\n'
> CalledProcessError: Command '/home/nikos/public_html/cgi-bin/pelatologio.py' returned non-zero exit status 1 
>       args = (1, '/home/nikos/public_html/cgi-bin/pelatologio.py') 
>       cmd = '/home/nikos/public_html/cgi-bin/pelatologio.py' 
>       output = b'<!--: spam\nContent-Type: text/html\n\n<body b...Type\' object has no attribute \'id\'\n\n-->\n\n' 
>       returncode = 1 
>       with_traceback = <built-in method with_traceback of CalledProcessError object>

Again the traceback is telling you where to look for the problem.  And
the problem is in your own script, pelatologio.py, though the line
number that's causing the problem is obscured.

Basically you want pelatologio.py to run and then you process the output
through a template, correct?

Well the traceback is telling you that pelatologio.py is erroring out.
In fact, subprocess is telling you that this process (your script) quit
with an error.  Though the line number in pelatologio.py is unknown (the
traceback is obscured by your html processing code in your template
processor), the error message itself is not.  Inside pelatologio.py
there is some object that you are trying to reference the "id" attribute
on it does not contain id.

So the problem is in pelatologio.py.  Double check your code there.  Try
to make a standalone test file you can run locally.


From nagia.retsina at gmail.com  Tue May 28 14:08:51 2013
From: nagia.retsina at gmail.com (nagia.retsina at gmail.com)
Date: Tue, 28 May 2013 11:08:51 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2307.1369761431.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
Message-ID: <0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>

?? ?????, 28 ????? 2013 8:17:05 ?.?. UTC+3, ? ??????? Michael Torrie ??????:

> Basically you want pelatologio.py to run and then you process the output
> through a template, correct?

That is correct.

> Inside pelatologio.py
> there is some object that you are trying to reference the "id" attribute
> on it does not contain id.
> So the problem is in pelatologio.py.  Double check your code there.  Try
> to make a standalone test file you can run locally.

I have, i see no error, the error appears only when i append the charset directive into the connector, if i remove it the error dissapears.


From joel.goldstick at gmail.com  Tue May 28 14:14:29 2013
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Tue, 28 May 2013 14:14:29 -0400
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
Message-ID: <CAPM-O+zpL0CG+4innodtSvMRW6Wph01L6eBzNWjRMDMuhBaQ-Q@mail.gmail.com>

On Tue, May 28, 2013 at 2:08 PM, <nagia.retsina at gmail.com> wrote:

> ?? ?????, 28 ????? 2013 8:17:05 ?.?. UTC+3, ? ??????? Michael Torrie
> ??????:
>
> > Basically you want pelatologio.py to run and then you process the output
> > through a template, correct?
>
> That is correct.
>
> > Inside pelatologio.py
> > there is some object that you are trying to reference the "id" attribute
> > on it does not contain id.
> > So the problem is in pelatologio.py.  Double check your code there.  Try
> > to make a standalone test file you can run locally.
>
> I have, i see no error, the error appears only when i append the charset
> directive into the connector, if i remove it the error dissapears.
> --
> http://mail.python.org/mailman/listinfo/python-list
>

http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect

Could this be the problem? ;)

-- 
Joel Goldstick
http://joelgoldstick.com
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From torriem at gmail.com  Tue May 28 14:19:21 2013
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 28 May 2013 12:19:21 -0600
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
Message-ID: <51A4F529.6090801@gmail.com>

On 05/28/2013 12:08 PM, nagia.retsina at gmail.com wrote:
> ?? ?????, 28 ????? 2013 8:17:05 ?.?. UTC+3, ? ??????? Michael Torrie
> ??????:
> 
>> Basically you want pelatologio.py to run and then you process the
>> output through a template, correct?
> 
> That is correct.
> 
>> Inside pelatologio.py there is some object that you are trying to
>> reference the "id" attribute on it does not contain id. So the
>> problem is in pelatologio.py.  Double check your code there.  Try 
>> to make a standalone test file you can run locally.
> 
> I have, i see no error, the error appears only when i append the
> charset directive into the connector, if i remove it the error
> dissapears.

No, when you remove the charset directive your database call fails and
thus things fail even earlier.


From nagia.retsina at gmail.com  Tue May 28 15:03:48 2013
From: nagia.retsina at gmail.com (nagia.retsina at gmail.com)
Date: Tue, 28 May 2013 12:03:48 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2313.1369765168.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
Message-ID: <2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>

?? ?????, 28 ????? 2013 9:19:21 ?.?. UTC+3, ? ??????? Michael Torrie ??????:
> On 05/28/2013 12:08 PM, nagia.retsina at gmail.com wrote:
> 
> > ?? ?????, 28 ????? 2013 8:17:05 ?.?. UTC+3, ? ??????? Michael Torrie
> 
> > ??????:
> 
> > 
> 
> >> Basically you want pelatologio.py to run and then you process the
> 
> >> output through a template, correct?
> 
> > 
> 
> > That is correct.
> 
> > 
> 
> >> Inside pelatologio.py there is some object that you are trying to
> 
> >> reference the "id" attribute on it does not contain id. So the
> 
> >> problem is in pelatologio.py.  Double check your code there.  Try 
> 
> >> to make a standalone test file you can run locally.
> 
> > 
> 
> > I have, i see no error, the error appears only when i append the
> 
> > charset directive into the connector, if i remove it the error
> 
> > dissapears.
> 
> 
> 
> No, when you remove the charset directive your database call fails and
> 
> thus things fail even earlier.

Yes, it does create issues.
i just tried to add it to metrites.py for testing and it breaks too.

https://github.com/petehunt/PyMySQL/issues/38

Switching back to MySQLdb.


From nagia.retsina at gmail.com  Tue May 28 15:48:38 2013
From: nagia.retsina at gmail.com (nagia.retsina at gmail.com)
Date: Tue, 28 May 2013 12:48:38 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
Message-ID: <332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>

But i think iam gonna fight it some more because mysqldb in python 3 has issues too :(


From nagia.retsina at gmail.com  Wed May 29 06:30:15 2013
From: nagia.retsina at gmail.com (nagia.retsina at gmail.com)
Date: Wed, 29 May 2013 03:30:15 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
Message-ID: <65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>

What makes us o sure it is a pymysql issue and not python's encoding issue?


From nagia.retsina at gmail.com  Thu May 30 04:16:46 2013
From: nagia.retsina at gmail.com (nagia.retsina at gmail.com)
Date: Thu, 30 May 2013 01:16:46 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <84fc3a0c-16d3-493e-bf65-217e9995ab26@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<84fc3a0c-16d3-493e-bf65-217e9995ab26@googlegroups.com>
Message-ID: <6e432384-1ae4-418a-82c3-6e3f4664666b@googlegroups.com>

Can ypou tell me how to install MySQLdb in python 3 using pip?

pip install MySQLdb doesnt find the module.


From torriem at gmail.com  Thu May 30 05:29:56 2013
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 30 May 2013 03:29:56 -0600
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
Message-ID: <51A71C14.5010009@gmail.com>

On 05/29/2013 04:30 AM, nagia.retsina at gmail.com wrote:
> What makes us o sure it is a pymysql issue and not python's encoding
> issue?

The original traceback, which showed that the encoding error was
happening in
"/opt/python3/lib/python3.3/site-packages/pymysql/cursors.py", line 108.
 As was said, you solve that by passing a charset="utf-8" to the
connection string.

So doing that solved the encoding problem (a query is now being
successfully built and sent to mysql) and went on to expose another
problem (bug) in your code, but I cannot tell what that is, since the
error happened in a subprocess and the traceback got sent to /dev/null.
 I suspect is has something to do with how the query results are being
returned, or it could have something to do with the query itself.
Python DB API does not specify exactly which style of prepared
statements should be used by a given third-party module.  So differences
in syntax between how pymysql and MysqlDB define the variables could be
the problem.

In any case your course is clear.  Run pelatologio.py outside of your
templating system and see what the traceback says exactly now that the
charset issue is fixed.



From nagia.retsina at gmail.com  Thu May 30 06:53:33 2013
From: nagia.retsina at gmail.com (nagia.retsina at gmail.com)
Date: Thu, 30 May 2013 03:53:33 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2398.1369906211.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<mailman.2398.1369906211.3114.python-list@python.org>
Message-ID: <626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>

?? ??????, 30 ????? 2013 12:29:56 ?.?. UTC+3, ? ??????? Michael Torrie ??????:
> On 05/29/2013 04:30 AM, nagia.retsina at gmail.com wrote:
> 
> > What makes us o sure it is a pymysql issue and not python's encoding
> 
> > issue?
> 
> 
> 
> The original traceback, which showed that the encoding error was
> 
> happening in
> 
> "/opt/python3/lib/python3.3/site-packages/pymysql/cursors.py", line 108.
> 
>  As was said, you solve that by passing a charset="utf-8" to the
> 
> connection string.
> 
> 
> 
> So doing that solved the encoding problem (a query is now being
> 
> successfully built and sent to mysql) and went on to expose another
> 
> problem (bug) in your code, but I cannot tell what that is, since the
> 
> error happened in a subprocess and the traceback got sent to /dev/null.
> 
>  I suspect is has something to do with how the query results are being
> 
> returned, or it could have something to do with the query itself.
> 
> Python DB API does not specify exactly which style of prepared
> 
> statements should be used by a given third-party module.  So differences
> 
> in syntax between how pymysql and MysqlDB define the variables could be
> 
> the problem.
> 
> 
> 
> In any case your course is clear.  Run pelatologio.py outside of your
> 
> templating system and see what the traceback says exactly now that the
> 
> charset issue is fixed.

Good morning Michael,

I'am afraid as much as you dont want to admin it that the moment i append the charset directive into the connections tring i receive a huge error which it can be displayed in:

http://superhost.gr/cgi-bin/pelatologio.py

This is run directly isolated form the templating system.


From nagia.retsina at gmail.com  Thu May 30 06:56:03 2013
From: nagia.retsina at gmail.com (nagia.retsina at gmail.com)
Date: Thu, 30 May 2013 03:56:03 -0700 (PDT)
Subject: Encodign  issue in Python 3.3.1 (once again)
In-Reply-To: <626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<mailman.2398.1369906211.3114.python-list@python.org>
	<626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
Message-ID: <34e69a6d-83a8-420a-a2a2-2a9ef64601ba@googlegroups.com>

?? ??????, 30 ????? 2013 1:53:33 ?.?. UTC+3, ? ??????? nagia.... at gmail.com ??????:
> ?? ??????, 30 ????? 2013 12:29:56 ?.?. UTC+3, ? ??????? Michael Torrie ??????:
> 
> > On 05/29/2013 04:30 AM, nagia.retsina at gmail.com wrote:
> 
> > 
> 
> > > What makes us o sure it is a pymysql issue and not python's encoding
> 
> > 
> 
> > > issue?
> 
> > 
> 
> > 
> 
> > 
> 
> > The original traceback, which showed that the encoding error was
> 
> > 
> 
> > happening in
> 
> > 
> 
> > "/opt/python3/lib/python3.3/site-packages/pymysql/cursors.py", line 108.
> 
> > 
> 
> >  As was said, you solve that by passing a charset="utf-8" to the
> 
> > 
> 
> > connection string.
> 
> > 
> 
> > 
> 
> > 
> 
> > So doing that solved the encoding problem (a query is now being
> 
> > 
> 
> > successfully built and sent to mysql) and went on to expose another
> 
> > 
> 
> > problem (bug) in your code, but I cannot tell what that is, since the
> 
> > 
> 
> > error happened in a subprocess and the traceback got sent to /dev/null.
> 
> > 
> 
> >  I suspect is has something to do with how the query results are being
> 
> > 
> 
> > returned, or it could have something to do with the query itself.
> 
> > 
> 
> > Python DB API does not specify exactly which style of prepared
> 
> > 
> 
> > statements should be used by a given third-party module.  So differences
> 
> > 
> 
> > in syntax between how pymysql and MysqlDB define the variables could be
> 
> > 
> 
> > the problem.
> 
> > 
> 
> > 
> 
> > 
> 
> > In any case your course is clear.  Run pelatologio.py outside of your
> 
> > 
> 
> > templating system and see what the traceback says exactly now that the
> 
> > 
> 
> > charset issue is fixed.
> 
> 
> 
> Good morning Michael,
> 
> 
> 
> I'am afraid as much as you dont want to admin it that the moment i append the charset directive into the connections tring i receive a huge error which it can be displayed in:
> 
> 
> 
> http://superhost.gr/cgi-bin/pelatologio.py
> 
> 
> 
> This is run directly isolated form the templating system.

AttributeError: 'NoneType' object has no attribute 'id' 
      args = ("'NoneType' object has no attribute 'id'",) 
      with_traceback = <built-in method with_traceback of AttributeError object>

is the error while i have no id varibale just an 'ID' inside:

cur.execute('''SELECT ID FROM clients WHERE name = %s''', (name,) )


From rosuav at gmail.com  Thu May 30 07:33:56 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 21:33:56 +1000
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<mailman.2398.1369906211.3114.python-list@python.org>
	<626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
Message-ID: <CAPTjJmqxpT8=S4EzYrOc+vBj-7_em1AD2C8PePjAKsFibkR9vA@mail.gmail.com>

On Thu, May 30, 2013 at 8:53 PM,  <nagia.retsina at gmail.com> wrote:
> Good morning Michael,
>
> I'am afraid as much as you dont want to admin it that the moment i append the charset directive into the connections tring i receive a huge error which it can be displayed in:
>
> http://superhost.gr/cgi-bin/pelatologio.py
>
> This is run directly isolated form the templating system.

Your valid character set names can be found here:

https://github.com/petehunt/PyMySQL/blob/master/pymysql/charset.py

I found this simply by googling 'pymysql' and working through the call tree.

Find what you want. Use it.

You can probably get this information from the docs, too. Read them.

ChrisA


From support at superhost.gr  Thu May 30 07:47:35 2013
From: support at superhost.gr (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Thu, 30 May 2013 04:47:35 -0700 (PDT)
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2405.1369913639.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<69f5q8hkra42rvpfmbng4f0airgikqf5js@4ax.com>
	<9560d43f-8100-4914-9a71-c30ab479ec35@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<mailman.2398.1369906211.3114.python-list@python.org>
	<626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
	<mailman.2405.1369913639.3114.python-list@python.org>
Message-ID: <56a24a19-e3ca-4188-a617-63da252917f3@googlegroups.com>

?? ??????, 30 ????? 2013 2:33:56 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
> On Thu, May 30, 2013 at 8:53 PM,  <nagia.retsina at gmail.com> wrote:
> 
> > Good morning Michael,
> 
> >
> 
> > I'am afraid as much as you dont want to admin it that the moment i append the charset directive into the connections tring i receive a huge error which it can be displayed in:
> 
> >
> 
> > http://superhost.gr/cgi-bin/pelatologio.py
> 
> >
> 
> > This is run directly isolated form the templating system.
> 
> 
> 
> Your valid character set names can be found here:
> 
> 
> 
> https://github.com/petehunt/PyMySQL/blob/master/pymysql/charset.py
> 
> 
> 
> I found this simply by googling 'pymysql' and working through the call tree.
> 
> 
> 
> Find what you want. Use it.
> 
> 
> 
> You can probably get this information from the docs, too. Read them.
> 
> 
> 
> ChrisA

I cant "fucking believe it".

The moen i switched "charset = 'utf-8'" => "charset = 'utf8'" all started to work properly!

Thank you very much Chris, i cnat belive i was lookign 3 days for that error and it was a matter of a dash removal.....My God!


From torriem at gmail.com  Thu May 30 10:35:09 2013
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 30 May 2013 08:35:09 -0600
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <56a24a19-e3ca-4188-a617-63da252917f3@googlegroups.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<mailman.2398.1369906211.3114.python-list@python.org>
	<626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
	<mailman.2405.1369913639.3114.python-list@python.org>
	<56a24a19-e3ca-4188-a617-63da252917f3@googlegroups.com>
Message-ID: <51A7639D.4000104@gmail.com>

On 05/30/2013 05:47 AM, ????? ???33? wrote:
> The moen i switched "charset = 'utf-8'" => "charset = 'utf8'" all
> started to work properly!

Glad you have it working.

Perhaps this should be a lesson to you, Nick.  Chris was able to spot
your problem by READING THE DOCUMENTATION, which he probably found
through some quick searching on Google.  These are things you can and
should do too.  As well as looking at the source code of the modules you
may have downloaded and are using, and understanding how the code works
(or fits together) and how to debug.  You seem to have a tendency to try
to attack your problems with rather blunt instruments, and then come to
the list where one of the list members invariable does the footwork for you.


From rosuav at gmail.com  Thu May 30 10:40:01 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 00:40:01 +1000
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <51A7639D.4000104@gmail.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<mailman.2251.1369665785.3114.python-list@python.org>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<mailman.2398.1369906211.3114.python-list@python.org>
	<626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
	<mailman.2405.1369913639.3114.python-list@python.org>
	<56a24a19-e3ca-4188-a617-63da252917f3@googlegroups.com>
	<51A7639D.4000104@gmail.com>
Message-ID: <CAPTjJmrkCC1geJqF8CMRBMmDfYqu5V8+rWjZujLZxkxJ37Sbgg@mail.gmail.com>

On Fri, May 31, 2013 at 12:35 AM, Michael Torrie <torriem at gmail.com> wrote:
> On 05/30/2013 05:47 AM, ????? ???33? wrote:
>> The moen i switched "charset = 'utf-8'" => "charset = 'utf8'" all
>> started to work properly!
>
> Glad you have it working.
>
> Perhaps this should be a lesson to you, Nick.  Chris was able to spot
> your problem by READING THE DOCUMENTATION, which he probably found
> through some quick searching on Google.  These are things you can and
> should do too.  As well as looking at the source code of the modules you
> may have downloaded and are using, and understanding how the code works
> (or fits together) and how to debug.

Well, actually I didn't find the documentation when I did those quick
web searches, which is why I ended up looking at the source. That
probably doubled the time requirement, and roughly doubled the minimum
skill points to cast this spell (programming is an RPG, right?), but
if he's actively using the module, he probably knows where to find its
docs.

ChrisA


From torriem at gmail.com  Thu May 30 13:01:25 2013
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 30 May 2013 11:01:25 -0600
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <CAPTjJmrkCC1geJqF8CMRBMmDfYqu5V8+rWjZujLZxkxJ37Sbgg@mail.gmail.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<mailman.2398.1369906211.3114.python-list@python.org>
	<626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
	<mailman.2405.1369913639.3114.python-list@python.org>
	<56a24a19-e3ca-4188-a617-63da252917f3@googlegroups.com>
	<51A7639D.4000104@gmail.com>
	<CAPTjJmrkCC1geJqF8CMRBMmDfYqu5V8+rWjZujLZxkxJ37Sbgg@mail.gmail.c
	om>
Message-ID: <51A785E5.7060509@gmail.com>

On 05/30/2013 08:40 AM, Chris Angelico wrote:
> but if he's actively using the module, he probably knows where to
> find its docs.

One would hope, but alas one probably hopes in vain.  I'm not sure he
wants to spend the time to read the code he's using and understand.
He's in too much of a hurry to simply get a result.



From rosuav at gmail.com  Thu May 30 13:28:56 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 03:28:56 +1000
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <51A785E5.7060509@gmail.com>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<mailman.2398.1369906211.3114.python-list@python.org>
	<626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
	<mailman.2405.1369913639.3114.python-list@python.org>
	<56a24a19-e3ca-4188-a617-63da252917f3@googlegroups.com>
	<51A7639D.4000104@gmail.com>
	<CAPTjJmrkCC1geJqF8CMRBMmDfYqu5V8+rWjZujLZxkxJ37Sbgg@mail.gmail.com>
	<51A785E5.7060509@gmail.com>
Message-ID: <CAPTjJmpXQ61nOdMW7Bzt-dpi_qgw=MXpjigt9W-=JXmqNtbtgQ@mail.gmail.com>

On Fri, May 31, 2013 at 3:01 AM, Michael Torrie <torriem at gmail.com> wrote:
> On 05/30/2013 08:40 AM, Chris Angelico wrote:
>> but if he's actively using the module, he probably knows where to
>> find its docs.
>
> One would hope, but alas one probably hopes in vain.  I'm not sure he
> wants to spend the time to read the code he's using and understand.
> He's in too much of a hurry to simply get a result.

Wonder how much less exciting this mailing list would be if he
switched to decaf...

*ducks for cover*

ChrisA


From nikos.gr33k at gmail.com  Fri May 31 11:13:09 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 08:13:09 -0700 (PDT)
Subject: Encodign issue in Python 3.3.1 (once again)
In-Reply-To: <mailman.2435.1369934945.3114.python-list@python.org>
References: <7823093c-2c07-4fa0-ae97-960c62f8ff9d@googlegroups.com>
	<f4c1b04a-7a50-418a-8be9-8a24609e261d@googlegroups.com>
	<mailman.2299.1369751680.3114.python-list@python.org>
	<a3405148-c74b-49d9-a37f-5fc19e7434f4@googlegroups.com>
	<mailman.2305.1369759217.3114.python-list@python.org>
	<d325d18f-9bb0-4a2e-9eb6-63d56c5aacbf@googlegroups.com>
	<mailman.2307.1369761431.3114.python-list@python.org>
	<0e3ef4e1-800f-40fc-8cdb-f9d1467266b0@googlegroups.com>
	<mailman.2313.1369765168.3114.python-list@python.org>
	<2217da95-178b-4af1-b816-af3ac5cb5f07@googlegroups.com>
	<332e8acf-7484-49ba-b2e9-5861a001c2e6@googlegroups.com>
	<65dff60d-5b85-47ab-8f9b-f5578998e807@googlegroups.com>
	<mailman.2398.1369906211.3114.python-list@python.org>
	<626eb9fc-3d4c-4818-8ce0-67562c9ed5b7@googlegroups.com>
	<mailman.2405.1369913639.3114.python-list@python.org>
	<56a24a19-e3ca-4188-a617-63da252917f3@googlegroups.com>
	<51A7639D.4000104@gmail.com>
	<CAPTjJmrkCC1geJqF8CMRBMmDfYqu5V8+rWjZujLZxkxJ37Sbgg@mail.gmail.com>
	<51A785E5.7060509@gmail.com>
	<mailman.2435.1369934945.3114.python-list@python.org>
Message-ID: <8572c6d7-0e3a-4147-be2a-9c890e1e6671@googlegroups.com>

?? ??????, 30 ????? 2013 8:28:56 ?.?. UTC+3, ? ??????? Chris Angelico ??????:

> Wonder how much less exciting this mailing list would be if he
> switched to decaf...

decaf is like tasting coffee without coffee!
Caffeine gives the coffee a nice taste and make me sweaty and panik too if when i struggle to find something :)

> *ducks for cover*

You don't have to hide :) I'am not after you yet!


From rvince99 at gmail.com  Sun May 26 13:52:14 2013
From: rvince99 at gmail.com (RVic)
Date: Sun, 26 May 2013 10:52:14 -0700 (PDT)
Subject: Cutting a deck of cards
Message-ID: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>

Suppose I have a deck of cards, and I shuffle them

import random
cards = []
decks = 6
cards = list(range(13 * 4 * decks))
random.shuffle(cards)

So now I have an array of cards. I would like to cut these cards at some random point (between 1 and 13 * 4 * decks - 1, moving the lower half of that to the top half of the cards array.

For some reason, I can't see how this can be done (I know that it must be a simple line or two in Python, but I am really stuck here). Anyone have any direction they can give me on this? Thanks, RVic, python newbie



From python at mrabarnett.plus.com  Sun May 26 14:04:52 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 26 May 2013 19:04:52 +0100
Subject: Cutting a deck of cards
In-Reply-To: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
Message-ID: <51A24EC4.7030904@mrabarnett.plus.com>

On 26/05/2013 18:52, RVic wrote:
> Suppose I have a deck of cards, and I shuffle them
>
> import random
> cards = []
> decks = 6
> cards = list(range(13 * 4 * decks))
> random.shuffle(cards)
>
> So now I have an array of cards. I would like to cut these cards at some random point (between 1 and 13 * 4 * decks - 1, moving the lower half of that to the top half of the cards array.
>
> For some reason, I can't see how this can be done (I know that it must be a simple line or two in Python, but I am really stuck here). Anyone have any direction they can give me on this? Thanks, RVic, python newbie
>
The list from its start up to, but excluding, index 'i' is cards[ : i],
and the list from index 'i' to its end is cards[i : ].

Now concatenate them those slices.


From mkamlesh at gmail.com  Sun May 26 14:05:51 2013
From: mkamlesh at gmail.com (Kamlesh Mutha)
Date: Sun, 26 May 2013 23:35:51 +0530
Subject: Cutting a deck of cards
In-Reply-To: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
Message-ID: <CADg3d1Pxrm8XWJxFKiiOAz5afcrXgA3_3OvKNvX2YKYFbcniPA@mail.gmail.com>

I guess, you will have to use list slicing mechanism to achieve the desired
result.

Hope this helps,

Cheers,
Kamlesh





On Sun, May 26, 2013 at 11:22 PM, RVic <rvince99 at gmail.com> wrote:

> Suppose I have a deck of cards, and I shuffle them
>
> import random
> cards = []
> decks = 6
> cards = list(range(13 * 4 * decks))
> random.shuffle(cards)
>
> So now I have an array of cards. I would like to cut these cards at some
> random point (between 1 and 13 * 4 * decks - 1, moving the lower half of
> that to the top half of the cards array.
>
> For some reason, I can't see how this can be done (I know that it must be
> a simple line or two in Python, but I am really stuck here). Anyone have
> any direction they can give me on this? Thanks, RVic, python newbie
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>



-- 
Faith waiting in the heart of a seed promises a miracle of life which it
can not prove!
-Ravindranath Tagore
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From carlosnepomuceno at outlook.com  Sun May 26 14:16:22 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 21:16:22 +0300
Subject: Cutting a deck of cards
In-Reply-To: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
Message-ID: <BLU176-W31C60A8378253850DA11CD7950@phx.gbl>

----------------------------------------
> Date: Sun, 26 May 2013 10:52:14 -0700
> Subject: Cutting a deck of cards
> From: rvince99 at gmail.com
> To: python-list at python.org
>
> Suppose I have a deck of cards, and I shuffle them
>
> import random
> cards = []
> decks = 6
> cards = list(range(13 * 4 * decks))
> random.shuffle(cards)
>
> So now I have an array of cards. I would like to cut these cards at some random point (between 1 and 13 * 4 * decks - 1, moving the lower half of that to the top half of the cards array.
>
> For some reason, I can't see how this can be done (I know that it must be a simple line or two in Python, but I am really stuck here). Anyone have any direction they can give me on this? Thanks, RVic, python newbie
>
> --
> http://mail.python.org/mailman/listinfo/python-list


list(range(13 * 4 * decks)) == range(13 * 4 * decks)

;) 		 	   		  

From ian.g.kelly at gmail.com  Sun May 26 14:47:02 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sun, 26 May 2013 18:47:02 -0000
Subject: Cutting a deck of cards
In-Reply-To: <BLU176-W31C60A8378253850DA11CD7950@phx.gbl>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<BLU176-W31C60A8378253850DA11CD7950@phx.gbl>
Message-ID: <CALwzid=tNvXMYQdx5RHqGqrJ5S_O5eh2TD19aacK6hZjjxxgVA@mail.gmail.com>

On Sun, May 26, 2013 at 12:16 PM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> list(range(13 * 4 * decks)) == range(13 * 4 * decks)

Not in Python 3.


From rosuav at gmail.com  Sun May 26 15:04:25 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 26 May 2013 19:04:25 -0000
Subject: Cutting a deck of cards
In-Reply-To: <BLU176-W31C60A8378253850DA11CD7950@phx.gbl>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<BLU176-W31C60A8378253850DA11CD7950@phx.gbl>
Message-ID: <CAPTjJmo_5g_vAe00SBpasFZ8j6toR-4=oTcJrt7PR=aGcWzcqQ@mail.gmail.com>

On Mon, May 27, 2013 at 4:16 AM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> list(range(13 * 4 * decks)) == range(13 * 4 * decks)
>
> ;)

Not in Python 3.

ChrisA


From breamoreboy at yahoo.co.uk  Sun May 26 18:17:56 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 23:17:56 +0100
Subject: Cutting a deck of cards
In-Reply-To: <BLU176-W31C60A8378253850DA11CD7950@phx.gbl>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<BLU176-W31C60A8378253850DA11CD7950@phx.gbl>
Message-ID: <knu1m3$egq$2@ger.gmane.org>

On 26/05/2013 19:16, Carlos Nepomuceno wrote:
> ----------------------------------------
>> Date: Sun, 26 May 2013 10:52:14 -0700
>> Subject: Cutting a deck of cards
>> From: rvince99 at gmail.com
>> To: python-list at python.org
>>
>> Suppose I have a deck of cards, and I shuffle them
>>
>> import random
>> cards = []
>> decks = 6
>> cards = list(range(13 * 4 * decks))
>> random.shuffle(cards)
>>
>> So now I have an array of cards. I would like to cut these cards at some random point (between 1 and 13 * 4 * decks - 1, moving the lower half of that to the top half of the cards array.
>>
>> For some reason, I can't see how this can be done (I know that it must be a simple line or two in Python, but I am really stuck here). Anyone have any direction they can give me on this? Thanks, RVic, python newbie
>>
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
>
> list(range(13 * 4 * decks)) == range(13 * 4 * decks)
>
> ;) 		 	   		
>

Wrong if you're using Python 3 :(

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From carlosnepomuceno at outlook.com  Sun May 26 18:30:53 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 27 May 2013 01:30:53 +0300
Subject: Cutting a deck of cards
In-Reply-To: <knu1m3$egq$2@ger.gmane.org>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>,
	<BLU176-W31C60A8378253850DA11CD7950@phx.gbl>,
	<knu1m3$egq$2@ger.gmane.org>
Message-ID: <BLU176-W25F96CC129855259547269D7950@phx.gbl>

----------------------------------------
> To: python-list at python.org
> From: breamoreboy at yahoo.co.uk
[...]
> Wrong if you're using Python 3 :(
>
> --
> If you're using GoogleCrap? please read this
> http://wiki.python.org/moin/GoogleGroupsPython.
>
> Mark Lawrence


Thanks guys! I've been delaying my dive into Python 3 (because I don't need it for now) but I'd like to run some code just to learn how different it is from Python 2 and even other Python flavors.

So, I'd like to know if it's possible to have multiple Python installations on the same machine (Windows 7 in my particular case) without messing one with each other. What care must I take not to mess up with them?

I've just found this[1] awesome service, but ridiculously it's PHP powered!!! lol Come on!!!

Why there aren't more Python powered websites available? What's the catch?


[1] http://www.compileonline.com/execute_python3_online.php 		 	   		  

From rosuav at gmail.com  Sun May 26 18:42:56 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 08:42:56 +1000
Subject: Cutting a deck of cards
In-Reply-To: <BLU176-W25F96CC129855259547269D7950@phx.gbl>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<BLU176-W31C60A8378253850DA11CD7950@phx.gbl>
	<knu1m3$egq$2@ger.gmane.org>
	<BLU176-W25F96CC129855259547269D7950@phx.gbl>
Message-ID: <CAPTjJmoZ+WbihideOdm2tfnu7ocuQCQYXfBTRRD697wDiuXgRQ@mail.gmail.com>

On Mon, May 27, 2013 at 8:30 AM, Carlos Nepomuceno
<carlosnepomuceno at outlook.com> wrote:
> Thanks guys! I've been delaying my dive into Python 3 (because I don't need it for now) but I'd like to run some code just to learn how different it is from Python 2 and even other Python flavors.
>
> So, I'd like to know if it's possible to have multiple Python installations on the same machine (Windows 7 in my particular case) without messing one with each other. What care must I take not to mess up with them?

Easy. Just grab the standard installer and hit it. You'll get two
separate directories (or more; I have \Python26, \Python27, \Python32,
\Python33 on this box), and you can run whichever you want. The one
thing to take care of is .py associations; I haven't actually done it
(on here, all I actually do is IDLE, pretty much), but as of 3.3, you
should be able to use a Unix-style shebang to indicate which Python
you want to invoke.

ChrisA


From carlosnepomuceno at outlook.com  Sun May 26 18:51:25 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 27 May 2013 01:51:25 +0300
Subject: Cutting a deck of cards
In-Reply-To: <CAPTjJmoZ+WbihideOdm2tfnu7ocuQCQYXfBTRRD697wDiuXgRQ@mail.gmail.com>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>,
	<BLU176-W31C60A8378253850DA11CD7950@phx.gbl>,
	<knu1m3$egq$2@ger.gmane.org>,
	<BLU176-W25F96CC129855259547269D7950@phx.gbl>,
	<CAPTjJmoZ+WbihideOdm2tfnu7ocuQCQYXfBTRRD697wDiuXgRQ@mail.gmail.com>
Message-ID: <BLU176-W912CC7830DE6108D118DFD7950@phx.gbl>

----------------------------------------
> Date: Mon, 27 May 2013 08:42:56 +1000
> Subject: Re: Cutting a deck of cards
> From: rosuav at gmail.com
[...]
> Easy. Just grab the standard installer and hit it. You'll get two
> separate directories (or more; I have \Python26, \Python27, \Python32,
> \Python33 on this box), and you can run whichever you want. The one
> thing to take care of is .py associations; I haven't actually done it
> (on here, all I actually do is IDLE, pretty much), but as of 3.3, you
> should be able to use a Unix-style shebang to indicate which Python
> you want to invoke.
>
> ChrisA

I'm not even using shebangs in Windows because I thought it wouldn't make any difference. I'm used to run scripts like "python filename.py" from the command line. No problem!

So, Python 3.3 will honor if I insert "#!C:\Python27\python.exe"? if I install it after Python 2.7? Cool!!! 		 	   		  

From breamoreboy at yahoo.co.uk  Sun May 26 18:56:37 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 23:56:37 +0100
Subject: Cutting a deck of cards
In-Reply-To: <CAPTjJmoZ+WbihideOdm2tfnu7ocuQCQYXfBTRRD697wDiuXgRQ@mail.gmail.com>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<BLU176-W31C60A8378253850DA11CD7950@phx.gbl>
	<knu1m3$egq$2@ger.gmane.org>
	<BLU176-W25F96CC129855259547269D7950@phx.gbl>
	<CAPTjJmoZ+WbihideOdm2tfnu7ocuQCQYXfBTRRD697wDiuXgRQ@mail.gmail.com>
Message-ID: <knu3um$agd$1@ger.gmane.org>

On 26/05/2013 23:42, Chris Angelico wrote:
> On Mon, May 27, 2013 at 8:30 AM, Carlos Nepomuceno
> <carlosnepomuceno at outlook.com> wrote:
>> Thanks guys! I've been delaying my dive into Python 3 (because I don't need it for now) but I'd like to run some code just to learn how different it is from Python 2 and even other Python flavors.
>>
>> So, I'd like to know if it's possible to have multiple Python installations on the same machine (Windows 7 in my particular case) without messing one with each other. What care must I take not to mess up with them?
>
> Easy. Just grab the standard installer and hit it. You'll get two
> separate directories (or more; I have \Python26, \Python27, \Python32,
> \Python33 on this box), and you can run whichever you want. The one
> thing to take care of is .py associations; I haven't actually done it
> (on here, all I actually do is IDLE, pretty much), but as of 3.3, you
> should be able to use a Unix-style shebang to indicate which Python
> you want to invoke.
>
> ChrisA
>

See this 
http://docs.python.org/3/whatsnew/3.3.html#pep-397-python-launcher-for-windows

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From carlosnepomuceno at outlook.com  Sun May 26 19:07:13 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 23:07:13 -0000
Subject: Cutting a deck of cards
In-Reply-To: <knu3um$agd$1@ger.gmane.org>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>,
	<BLU176-W31C60A8378253850DA11CD7950@phx.gbl>,
	<knu1m3$egq$2@ger.gmane.org>,
	<BLU176-W25F96CC129855259547269D7950@phx.gbl>,
	<CAPTjJmoZ+WbihideOdm2tfnu7ocuQCQYXfBTRRD697wDiuXgRQ@mail.gmail.com>,
	<knu3um$agd$1@ger.gmane.org>
Message-ID: <BLU176-W341E27DB7E195558604C3FD7950@phx.gbl>

----------------------------------------
> To: python-list at python.org
> From: breamoreboy at yahoo.co.uk
[...]
> See this
> http://docs.python.org/3/whatsnew/3.3.html#pep-397-python-launcher-for-windows
>
> --
> If you're using GoogleCrap? please read this
> http://wiki.python.org/moin/GoogleGroupsPython.
>
> Mark Lawrence

Piece of cake! So, is there any risk of breaking anything if I install a new package after having both Puthon 2 and 3 installed?

How do I choose which one will run the package? Will the package handle the settings accordingly or will I need to setup manually? 		 	   		  

From rvince99 at gmail.com  Sun May 26 14:17:36 2013
From: rvince99 at gmail.com (RVic)
Date: Sun, 26 May 2013 11:17:36 -0700 (PDT)
Subject: Cutting a deck of cards
In-Reply-To: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
Message-ID: <db53cc7f-3a99-4e12-84d1-dbd05aeb1e5f@googlegroups.com>

Ah, brilliant -- yes, this is so much more elegant in Python:

#now cut the cards
x = random.randrange(2,range(13 * 4 * decks))
cards = cards[x:]+cards[:x]


From ian.g.kelly at gmail.com  Sun May 26 14:28:59 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sun, 26 May 2013 18:28:59 -0000
Subject: Cutting a deck of cards
In-Reply-To: <db53cc7f-3a99-4e12-84d1-dbd05aeb1e5f@googlegroups.com>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<db53cc7f-3a99-4e12-84d1-dbd05aeb1e5f@googlegroups.com>
Message-ID: <CALwzidkii6+oMuN8GyAzFJa2ezFKO-4hjV7gfN+6e22gyXC3nQ@mail.gmail.com>

On Sun, May 26, 2013 at 12:17 PM, RVic <rvince99 at gmail.com> wrote:
> Ah, brilliant -- yes, this is so much more elegant in Python:
>
> #now cut the cards
> x = random.randrange(2,range(13 * 4 * decks))
> cards = cards[x:]+cards[:x]

Or if for some reason you want to do it in place:

cards[x:], cards[:x] = cards[:x], cards[x:]

But note that the order of assignments is subtly important there, so
unless you have a good reason for doing that, it's probably better
just to create a new list for clarity.


From roy at panix.com  Sun May 26 14:21:29 2013
From: roy at panix.com (Roy Smith)
Date: Sun, 26 May 2013 14:21:29 -0400
Subject: Cutting a deck of cards
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
Message-ID: <roy-C7646D.14212926052013@news.panix.com>

In article <4d02f46f-8264-41bf-a254-d1c20469626e at googlegroups.com>,
 RVic <rvince99 at gmail.com> wrote:

> Suppose I have a deck of cards, and I shuffle them
> 
> import random
> cards = []
> decks = 6
> cards = list(range(13 * 4 * decks))
> random.shuffle(cards)
> 
> So now I have an array of cards. I would like to cut these cards at some 
> random point (between 1 and 13 * 4 * decks - 1, moving the lower half of that 
> to the top half of the cards array.
> 
> For some reason, I can't see how this can be done (I know that it must be a 
> simple line or two in Python, but I am really stuck here). Anyone have any 
> direction they can give me on this? Thanks, RVic, python newbie

import random
i = random.randrange(len(cards))
cut1 = cards[:i]
cut2 = cards[i:]

I haven't thought too much about the boundary conditions, but that's the 
general idea.


From usenetmail at solar-empire.de  Sun May 26 15:36:42 2013
From: usenetmail at solar-empire.de (Marc Christiansen)
Date: Sun, 26 May 2013 21:36:42 +0200
Subject: Cutting a deck of cards
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<mailman.2186.1369592184.3114.python-list@python.org>
Message-ID: <ar4a7a-cmt.ln1@pluto.solar-empire.de>

Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> ----------------------------------------
>> Date: Sun, 26 May 2013 10:52:14 -0700
>> Subject: Cutting a deck of cards
>> From: rvince99 at gmail.com
>> To: python-list at python.org
>>
>> Suppose I have a deck of cards, and I shuffle them
>>
>> import random
>> cards = []
>> decks = 6
>> cards = list(range(13 * 4 * decks))
>> random.shuffle(cards)
>>
>> So now I have an array of cards. I would like to cut these cards at
>> some random point (between 1 and 13 * 4 * decks - 1, moving the lower
>> half of that to the top half of the cards array.
>>
>> For some reason, I can't see how this can be done (I know that it
>> must be a simple line or two in Python, but I am really stuck here).
>> Anyone have any direction they can give me on this? Thanks, RVic,
>> python newbie
>>
>> --
>> http://mail.python.org/mailman/listinfo/python-list
> 
> 
> list(range(13 * 4 * decks)) == range(13 * 4 * decks)
> 
> ;)                                        

Not in Python3.x
>>> decks = 6
>>> list(range(13 * 4 * decks)) == range(13 * 4 * decks)
False

Adia?
Marc


From carlosnepomuceno at outlook.com  Sun May 26 15:54:44 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 22:54:44 +0300
Subject: Cutting a deck of cards
In-Reply-To: <ar4a7a-cmt.ln1@pluto.solar-empire.de>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>,
	<mailman.2186.1369592184.3114.python-list@python.org>,
	<ar4a7a-cmt.ln1@pluto.solar-empire.de>
Message-ID: <BLU176-W159F0EA24AACCE98C68A2AD7950@phx.gbl>

----------------------------------------
> From: usenetmail at solar-empire.de
[...]
> Not in Python3.x
>>>> decks = 6
>>>> list(range(13 * 4 * decks)) == range(13 * 4 * decks)
> False
>
> Adia?
> Marc


What does "list(range(13 * 4 * decks))" returns in Python 3? 		 	   		  

From tjreedy at udel.edu  Sun May 26 17:03:39 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Sun, 26 May 2013 17:03:39 -0400
Subject: Cutting a deck of cards
In-Reply-To: <BLU176-W159F0EA24AACCE98C68A2AD7950@phx.gbl>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>,
	<mailman.2186.1369592184.3114.python-list@python.org>,
	<ar4a7a-cmt.ln1@pluto.solar-empire.de>
	<BLU176-W159F0EA24AACCE98C68A2AD7950@phx.gbl>
Message-ID: <knttau$f50$1@ger.gmane.org>

On 5/26/2013 3:54 PM, Carlos Nepomuceno wrote:
> ----------------------------------------
>> From: usenetmail at solar-empire.de
> [...]
>> Not in Python3.x
>>>>> decks = 6
>>>>> list(range(13 * 4 * decks)) == range(13 * 4 * decks)
>> False
>>
>> Adia?
>> Marc
>
>
> What does "list(range(13 * 4 * decks))" returns in Python 3? 	

A list, obviously. What you should ask is what range returns in Python 
3, and you should install python 3 and try it, and list its attributes.
	 	   		




From usenetmail at solar-empire.de  Sun May 26 16:13:55 2013
From: usenetmail at solar-empire.de (Marc Christiansen)
Date: Sun, 26 May 2013 22:13:55 +0200
Subject: Cutting a deck of cards
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<mailman.2186.1369592184.3114.python-list@python.org>
	<ar4a7a-cmt.ln1@pluto.solar-empire.de>
	<mailman.2194.1369598093.3114.python-list@python.org>
Message-ID: <317a7a-jot.ln1@pluto.solar-empire.de>

Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> ----------------------------------------
>> From: usenetmail at solar-empire.de
> [...]
>> Not in Python3.x
>>>>> decks = 6
>>>>> list(range(13 * 4 * decks)) == range(13 * 4 * decks)
>> False
> 
> What does "list(range(13 * 4 * decks))" returns in Python 3?                                      

A list of course. But Py3 range is very similar to Py2 xrange, it
returns a range object.

Adia?
Marc


From usenetmail at solar-empire.de  Sun May 26 16:13:55 2013
From: usenetmail at solar-empire.de (Marc Christiansen)
Date: Sun, 26 May 2013 22:13:55 +0200
Subject: Cutting a deck of cards
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<mailman.2186.1369592184.3114.python-list@python.org>
	<ar4a7a-cmt.ln1@pluto.solar-empire.de>
	<mailman.2194.1369598093.3114.python-list@python.org>
Message-ID: <317a7a-jot.ln1@pluto.solar-empire.de>

Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> ----------------------------------------
>> From: usenetmail at solar-empire.de
> [...]
>> Not in Python3.x
>>>>> decks = 6
>>>>> list(range(13 * 4 * decks)) == range(13 * 4 * decks)
>> False
> 
> What does "list(range(13 * 4 * decks))" returns in Python 3?                                      

A list of course. But Py3 range is very similar to Py2 xrange, it
returns a range object.

Adia?
Marc


From carlosnepomuceno at outlook.com  Sun May 26 16:35:51 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Sun, 26 May 2013 20:35:51 -0000
Subject: Cutting a deck of cards
In-Reply-To: <317a7a-jot.ln1@pluto.solar-empire.de>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>,
	<mailman.2186.1369592184.3114.python-list@python.org>,
	<ar4a7a-cmt.ln1@pluto.solar-empire.de>,
	<mailman.2194.1369598093.3114.python-list@python.org>,
	<317a7a-jot.ln1@pluto.solar-empire.de>
Message-ID: <BLU176-W231B1E4B8E6914B5DB6C2DD7950@phx.gbl>

----------------------------------------
> From: usenetmail at solar-empire.de
> Subject: Re: Cutting a deck of cards
> Date: Sun, 26 May 2013 22:13:55 +0200
> To: python-list at python.org
>
> Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
>> ----------------------------------------
>>> From: usenetmail at solar-empire.de
>> [...]
>>> Not in Python3.x
>>>>>> decks = 6
>>>>>> list(range(13 * 4 * decks)) == range(13 * 4 * decks)
>>> False
>>
>> What does "list(range(13 * 4 * decks))" returns in Python 3?
>
> A list of course. But Py3 range is very similar to Py2 xrange, it
> returns a range object.
>
> Adia?
> Marc

What list? '[[0,1,2,...]]' or '[0,1,2,...]'? If it's the later then it's no different than what range() returns in Python 2.7.5! 		 	   		  

From leedanielcrocker at gmail.com  Fri May 31 07:56:50 2013
From: leedanielcrocker at gmail.com (Lee Crocker)
Date: Fri, 31 May 2013 04:56:50 -0700 (PDT)
Subject: Cutting a deck of cards
In-Reply-To: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
Message-ID: <4286e1af-f97c-4111-ab3d-cdf2e2fa5fa8@googlegroups.com>

Why on Earth would you want to? "Cutting" a deck makes no sense in software. Randomize the deck properly (Google "Fisher-Yates") and start dealing. Cutting the deck will not make it any more random, and in fact will probably make it worse depending on how you choose the cutpoint.

The purpose of "cutting" cards is to make it more difficult for human dealers to stack a deck. Simulating it in software makes no more sense than simulating the cigars you smoke while playing.


From modulok at gmail.com  Fri May 31 14:54:22 2013
From: modulok at gmail.com (Modulok)
Date: Fri, 31 May 2013 12:54:22 -0600
Subject: Cutting a deck of cards
In-Reply-To: <4286e1af-f97c-4111-ab3d-cdf2e2fa5fa8@googlegroups.com>
References: <4d02f46f-8264-41bf-a254-d1c20469626e@googlegroups.com>
	<4286e1af-f97c-4111-ab3d-cdf2e2fa5fa8@googlegroups.com>
Message-ID: <CAN2+EpZAULLK+9sQ02L+ccYt=dkW6XCnrpTPqXTGdBwiFK2_Eg@mail.gmail.com>

> Why on Earth would you want to? "Cutting" a deck makes no sense in
> software. Randomize the deck properly (Google "Fisher-Yates") and start
> dealing. Cutting the deck will not make it any more random, and in fact
> will probably make it worse depending on how you choose the cutpoint.
>
> The purpose of "cutting" cards is to make it more difficult for human
> dealers to stack a deck. Simulating it in software makes no more sense than
> simulating the cigars you smoke while playing.
>
>
Perhaps the OP wanted to study the efficiency and affect of a real-world
shuffling algorithm :-p Maybe he was designing a probabilistic magic trick
and
needed to evaluate how a cut would modify the outcome of a particular stack.
Maybe it was a school assignment. Who knows?

(But yeah if the purpose was for pure randomization then there's no real
point.)

There could be a lot of legitimate reasons though.
-Modulok-
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From danielgagliardiramos at gmail.com  Sun May 26 15:10:28 2013
From: danielgagliardiramos at gmail.com (Daniel Gagliardi)
Date: Sun, 26 May 2013 16:10:28 -0300
Subject: I want to know how to implement concurrent threads in Python
Message-ID: <CAGpAtSFH5Gn1xWuPKhGm-Bo0OZi0PgOD+9O-KC=MpCXJ20bC6w@mail.gmail.com>

I want to know how to implement concurrent threads in Python
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From bahamutzero8825 at gmail.com  Sun May 26 17:10:51 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Sun, 26 May 2013 16:10:51 -0500
Subject: I want to know how to implement concurrent threads in Python
In-Reply-To: <CAGpAtSFH5Gn1xWuPKhGm-Bo0OZi0PgOD+9O-KC=MpCXJ20bC6w@mail.gmail.com>
References: <CAGpAtSFH5Gn1xWuPKhGm-Bo0OZi0PgOD+9O-KC=MpCXJ20bC6w@mail.gmail.com>
Message-ID: <51A27A5B.1030304@gmail.com>

On 2013.05.26 14:10, Daniel Gagliardi wrote:
> I want to know how to implement concurrent threads in Python
With the threading module in the standard library.
http://docs.python.org/3.3/library/threading.html

There are plenty of tutorials on this out there; we'll be happy to help if you're stuck on something specific.
-- 
CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1


From bahamutzero8825 at gmail.com  Sun May 26 17:27:16 2013
From: bahamutzero8825 at gmail.com (Andrew Berg)
Date: Sun, 26 May 2013 16:27:16 -0500
Subject: I want to know how to implement concurrent threads in Python
In-Reply-To: <CAGpAtSGQ1dS=EjDGzgZxcO40dwMqhMsQ+yy_xiFqid4zHMeXsw@mail.gmail.com>
References: <CAGpAtSFH5Gn1xWuPKhGm-Bo0OZi0PgOD+9O-KC=MpCXJ20bC6w@mail.gmail.com>
	<51A27A5B.1030304@gmail.com>
	<CAGpAtSGQ1dS=EjDGzgZxcO40dwMqhMsQ+yy_xiFqid4zHMeXsw@mail.gmail.com>
Message-ID: <51A27E34.2020406@gmail.com>

On 2013.05.26 16:21, Daniel Gagliardi wrote:
> shutup bitch! i do know python cannot concurrent threads. want a workaround
You're a charming fellow. I'm sure everyone will flock to help you.


From breamoreboy at yahoo.co.uk  Sun May 26 18:24:45 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 23:24:45 +0100
Subject: I want to know how to implement concurrent threads in Python
In-Reply-To: <51A27E34.2020406@gmail.com>
References: <CAGpAtSFH5Gn1xWuPKhGm-Bo0OZi0PgOD+9O-KC=MpCXJ20bC6w@mail.gmail.com>
	<51A27A5B.1030304@gmail.com>
	<CAGpAtSGQ1dS=EjDGzgZxcO40dwMqhMsQ+yy_xiFqid4zHMeXsw@mail.gmail.com>
	<51A27E34.2020406@gmail.com>
Message-ID: <knu22t$egq$4@ger.gmane.org>

On 26/05/2013 22:27, Andrew Berg wrote:
> On 2013.05.26 16:21, Daniel Gagliardi wrote:
>> shutup bitch! i do know python cannot concurrent threads. want a workaround
> You're a charming fellow. I'm sure everyone will flock to help you.
>

So "How to win friends and influence people" had two authors.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Sun May 26 18:25:42 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 26 May 2013 23:25:42 +0100
Subject: I want to know how to implement concurrent threads in Python
In-Reply-To: <CAGpAtSFH5Gn1xWuPKhGm-Bo0OZi0PgOD+9O-KC=MpCXJ20bC6w@mail.gmail.com>
References: <CAGpAtSFH5Gn1xWuPKhGm-Bo0OZi0PgOD+9O-KC=MpCXJ20bC6w@mail.gmail.com>
Message-ID: <knu24m$egq$5@ger.gmane.org>

On 26/05/2013 20:10, Daniel Gagliardi wrote:
> I want to know how to implement concurrent threads in Python
>

google, bing, duckduckgo, yahoo...

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From danielgagliardiramos at gmail.com  Mon May 27 23:58:58 2013
From: danielgagliardiramos at gmail.com (Daniel Gagliardi)
Date: Tue, 28 May 2013 00:58:58 -0300
Subject: I want to know how to implement concurrent threads in Python
In-Reply-To: <knu24m$egq$5@ger.gmane.org>
References: <CAGpAtSFH5Gn1xWuPKhGm-Bo0OZi0PgOD+9O-KC=MpCXJ20bC6w@mail.gmail.com>
	<knu24m$egq$5@ger.gmane.org>
Message-ID: <CAGpAtSGJNVniWdoJsFPaFNSndCTB55CteAbjYxEpMWvXZf-uFg@mail.gmail.com>

fuck! fuck! i'm gonna be fired if i didnt get this shit! i told my boss id
do it. fuck! im gonna pipe some crakc. fuck...


2013/5/26 Mark Lawrence <breamoreboy at yahoo.co.uk>

> On 26/05/2013 20:10, Daniel Gagliardi wrote:
>
>> I want to know how to implement concurrent threads in Python
>>
>>
> google, bing, duckduckgo, yahoo...
>
>
> --
> If you're using GoogleCrap? please read this http://wiki.python.org/moin/*
> *GoogleGroupsPython <http://wiki.python.org/moin/GoogleGroupsPython>.
>
> Mark Lawrence
>
> --
> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>
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From fabiosantosart at gmail.com  Tue May 28 02:02:23 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 28 May 2013 07:02:23 +0100
Subject: I want to know how to implement concurrent threads in Python
In-Reply-To: <CAGpAtSGJNVniWdoJsFPaFNSndCTB55CteAbjYxEpMWvXZf-uFg@mail.gmail.com>
References: <CAGpAtSFH5Gn1xWuPKhGm-Bo0OZi0PgOD+9O-KC=MpCXJ20bC6w@mail.gmail.com>
	<knu24m$egq$5@ger.gmane.org>
	<CAGpAtSGJNVniWdoJsFPaFNSndCTB55CteAbjYxEpMWvXZf-uFg@mail.gmail.com>
Message-ID: <CAA=1kxTPEhBELB4FCzYfpziarJF93CY+MFN1RLLKymv-E+OUtQ@mail.gmail.com>

On 28 May 2013 05:06, "Daniel Gagliardi" <danielgagliardiramos at gmail.com>
wrote:
>
> fuck! fuck! i'm gonna be fired if i didnt get this shit! i told my boss
id do it. fuck! im gonna pipe some crakc. fuck...

So do it. You've already been told how to.

It's true that python does not do real concurrent execution, but if most of
your threads spend most time sleeping, waiting on a socket or doing IO,
those are opportunities for other threads to cut in and execute
concurrently and the threading module is your best choice.

If you need to do cpu-intensive tasks concurrently, use the multiprocessing
module.
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From ulrich.eckhardt at dominolaser.com  Tue May 28 03:49:50 2013
From: ulrich.eckhardt at dominolaser.com (Ulrich Eckhardt)
Date: Tue, 28 May 2013 09:49:50 +0200
Subject: I want to know how to implement concurrent threads in Python
In-Reply-To: <mailman.2195.1369599054.3114.python-list@python.org>
References: <mailman.2195.1369599054.3114.python-list@python.org>
Message-ID: <u54e7a-s6f.ln1@satorlaser.homedns.org>

Am 26.05.2013 21:10, schrieb Daniel Gagliardi:
> I want to know how to implement concurrent threads in Python

Have you tried searching the web or maybe looked on docs.python.org? 
Seriously, show at least some effort before asking here.

Uli



From carlosnepomuceno at outlook.com  Sun May 26 19:13:54 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 27 May 2013 02:13:54 +0300
Subject: Python error codes and messages location
Message-ID: <BLU176-W7E060AF58550322F411D2D7950@phx.gbl>

Where can I find all error codes and messages that Python throws (actual codes and messages from exceptions raised by stdlib)?

I've already found the module 'errno' and got a dictionary (errno.errorcode) and some system error messages (os.strerror(errno.ENAMETOOLONG)) but there's more I couldn't find. 		 	   		  

From steve+comp.lang.python at pearwood.info  Sun May 26 20:53:41 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 27 May 2013 00:53:41 GMT
Subject: Python error codes and messages location
References: <mailman.2221.1369610041.3114.python-list@python.org>
Message-ID: <51a2ae95$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Mon, 27 May 2013 02:13:54 +0300, Carlos Nepomuceno wrote:

> Where can I find all error codes and messages that Python throws (actual
> codes and messages from exceptions raised by stdlib)?

There is no list. It is subject to change from version to version, 
including point releases.

Many functions and methods document which exceptions they can be expected 
to raise, or at least the *usual* exceptions, but many more do not. And 
the error messages themselves are implementation details and are subject 
to change without notice, even if the exception type is a documented part 
of the API.

You can see a full list of built-in exception types in the docs:

http://docs.python.org/3/library/exceptions.html

but of course since they are classes, they can be subclassed, and in 
principle a function that raises (say) ValueError might sometimes raise a 
subclass of ValueError without documenting it.

So the actual answer to your question is:

"Read the source code."


Sorry :-(


> I've already found the module 'errno' and got a dictionary
> (errno.errorcode) and some system error messages
> (os.strerror(errno.ENAMETOOLONG)) but there's more I couldn't find.

These are the standard C operating system and file system error codes, 
not Python exceptions.


-- 
Steven


From carlosnepomuceno at outlook.com  Sun May 26 21:49:28 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 27 May 2013 04:49:28 +0300
Subject: Python error codes and messages location
In-Reply-To: <51a2ae95$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.2221.1369610041.3114.python-list@python.org>,
	<51a2ae95$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>

----------------------------------------
> From: steve+comp.lang.python at pearwood.info
> Subject: Re: Python error codes and messages location
> Date: Mon, 27 May 2013 00:53:41 +0000
> To: python-list at python.org
>
> On Mon, 27 May 2013 02:13:54 +0300, Carlos Nepomuceno wrote:
>
>> Where can I find all error codes and messages that Python throws (actual
>> codes and messages from exceptions raised by stdlib)?
>
> There is no list. It is subject to change from version to version,
> including point releases.
>
> Many functions and methods document which exceptions they can be expected
> to raise, or at least the *usual* exceptions, but many more do not. And
> the error messages themselves are implementation details and are subject
> to change without notice, even if the exception type is a documented part
> of the API.
>
> You can see a full list of built-in exception types in the docs:
>
> http://docs.python.org/3/library/exceptions.html
>
> but of course since they are classes, they can be subclassed, and in
> principle a function that raises (say) ValueError might sometimes raise a
> subclass of ValueError without documenting it.
>
> So the actual answer to your question is:
>
> "Read the source code."
>
>
> Sorry :-(

That's bad! I'd like to check all the IOError codes that may be raised by a function/method but the information isn't there.

Take open() for example[1]. It only says it raises an IOError exception.

I've had to try "open('','r')" to discover that Errno 22 is the one "IOError: [Errno 22] invalid mode ('r') or filename: ''"

Will I only be able to get all error codes reading the source code of open()?

Is there a way to simulate the errors instead of actually causing them? I mean not raising an instance of IOError that I create (like "raise IOError(666,'Hell happens')"), but one with the actual contents 'args = (errno, strerr)' that open() would raise?

Something like:

f=open('filename','r')
for x in range(25):
??? try:
??????? f.raise_errno(x)
??? except IOError, e:
??????? if?? e.errno == 1:
??????????? treat_err1()
??????????? continue
??????? elif e.errno == 2:
??????????? treat_err2()
??????????? continue
...



[1] http://docs.python.org/2/library/functions.html#open

>> I've already found the module 'errno' and got a dictionary
>> (errno.errorcode) and some system error messages
>> (os.strerror(errno.ENAMETOOLONG)) but there's more I couldn't find.
>
> These are the standard C operating system and file system error codes,
> not Python exceptions.

Yes, the docs say it's from "linux/include/errno.h". 		 	   		  

From cs at zip.com.au  Mon May 27 02:11:54 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 27 May 2013 16:11:54 +1000
Subject: Python error codes and messages location
In-Reply-To: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
Message-ID: <20130527061154.GA3301@cskk.homeip.net>

On 27May2013 04:49, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
| > From: steve+comp.lang.python at pearwood.info
| > On Mon, 27 May 2013 02:13:54 +0300, Carlos Nepomuceno wrote:
| >> Where can I find all error codes and messages that Python throws (actual
| >> codes and messages from exceptions raised by stdlib)?
| >
| > There is no list. It is subject to change from version to version,
| > including point releases.
[...]
| > "Read the source code."
[...]
| 
| That's bad! I'd like to check all the IOError codes that may be
| raised by a function/method but the information isn't there.

No, you really don't.

There are particular, expected, errors you know what to do with
and can proceed in the face of.

And there will often be errors you _don't_ know what to do with.
With the latter, what is your program going to do? You often can't
proceed, so all you can do is log the error and cancel, cleaning
up as you back out. In that circumstance, how will knowing the name
of the error help? You've logged it, and hopefully the exception
message is sufficient.

| Take open() for example[1]. It only says it raises an IOError exception.
| 
| I've had to try "open('','r')" to discover that Errno 22 is the one "IOError: [Errno 22] invalid mode ('r') or filename: ''"

It is vague because that is an OS level error, and errno 22 is
EINVAL. For example, MacOSX says (in "man 2 intro"):

     22 EINVAL Invalid argument.  Some invalid argument was supplied. (For
             example, specifying an undefined signal to a signal or kill func?
             tion).

It happens that above, the filename '' is invalid.

But so what? That call is _never_ going to work because the arguments
are invalid. So you response will be the same, programmatically,
as with many other errors: log and abort.

| Will I only be able to get all error codes reading the source code of open()?

Nope. Well, not directly.

Python open call's the OS' open. If that succeeds, Python does some
more housekeeping and hands you a "file" python object. But if the
OS open fails, Python reports the OS error.

From the Python source you will see that the OS open is called. So
you must then go to the OS docuemntation for further information.

| Is there a way to simulate the errors instead of actually causing
| them? I mean not raising an instance of IOError that I create (like
| "raise IOError(666,'Hell happens')"), but one with the actual
| contents 'args = (errno, strerr)' that open() would raise?
| 
| Something like:
| 
| f=open('filename','r')
| for x in range(25):
| ??? try:
| ??????? f.raise_errno(x)
| ??? except IOError, e:
| ??????? if?? e.errno == 1:
| ??????????? treat_err1()
| ??????????? continue
| ??????? elif e.errno == 2:
| ??????????? treat_err2()
| ??????????? continue

Well, maybe this (untested):

  for x in range(25):
  ??? try:
  ??????? exc = OSError(os.strerror(x))
          exc.errno = x
          raise exc
  ??? except IOError, e:
  ??????? if?? e.errno == 1:
  ??????????? treat_err1()
  ??????????? continue
  ??????? elif e.errno == 2:
  ??????????? treat_err2()
  ??????????? continue

BTW, I recommend importing "errno" and using symbolic names. It makes things much more readable, and accomodates the situation where the symbols map to different numbers on different platforms. And have a catch-all. For example:

  import errno
  ...
  try:
    f = open(filename, .....)
  except OSError, e:
    if e.errno == errno.EPERM:
      ... Operation not permitted ...
    elif e.errno == errno.ENOENT:
      ... No such file or directory ...
    else:
      # surprise!
      # log message, let the exception get out
      # callers can catch things in turn
      logging.error("open(%s) fails: %s" % (filename, e))
      raise

| >> I've already found the module 'errno' and got a dictionary
| >> (errno.errorcode) and some system error messages
| >> (os.strerror(errno.ENAMETOOLONG)) but there's more I couldn't find.
| >
| > These are the standard C operating system and file system error codes,
| > not Python exceptions.
| 
| Yes, the docs say it's from "linux/include/errno.h". 		 	   		  

On Linux, yes. In general, on any UNIX system the command "man 2
intro" lists the errors that system calls like open may return. And
"man 2 open" should list the particular errors that open can return.
_On that platform_.

The platform variation is a major reason why you should not hope
to enumerate all the errors; the other reason is that you can't
treat every error individually in a fine grained fashion without
making your code hard to read and maintain: the core logic of the
program is hidden behind a forest of tiny little special cases.

Your code will be clearer if you handle the errors that are expected
and that permit the program to proceed sensible. Other errors should
elicit a log message of course, but if you can't proceed with the
task at hand you can almost certainly only abort and try to tidy
up while doing so.

Cheers,
-- 

Processes are like potatoes.    - NCR device driver manual


From rosuav at gmail.com  Mon May 27 03:47:45 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 27 May 2013 17:47:45 +1000
Subject: Python error codes and messages location
In-Reply-To: <20130527061154.GA3301@cskk.homeip.net>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
Message-ID: <CAPTjJmo91BKfM40ifwyATX8TbPECKM=hQJ6kG9MnKQkwh-eg+g@mail.gmail.com>

On Mon, May 27, 2013 at 4:11 PM, Cameron Simpson <cs at zip.com.au> wrote:
> On 27May2013 04:49, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:
> | That's bad! I'd like to check all the IOError codes that may be
> | raised by a function/method but the information isn't there.
>
> No, you really don't.

Heh. I concur. Opening a file can generate roughly forty-two million
different errors. Here's a smattering that you might not be expecting:

* The path points somewhere that's not currently mounted
* The path represents a device that is not properly working
* It's over a network and the server at the far end is down
* It's over a network and the server sends back maliciously crafted data
* It's over a network and the server sends back an incorrect error code
* You tried to open something that doesn't exist, and your disk quota is used up
* The system has run out of handles
* You're trying to create something in the root directory of a FAT
volume that already has too many root directory entries

And plenty more besides. Those are just a few that I could come up
with off the top of my head.

Just catch whatever makes sense (IOError maybe), and don't sweat the details.

ChrisA


From breamoreboy at yahoo.co.uk  Mon May 27 07:37:12 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 27 May 2013 12:37:12 +0100
Subject: Python error codes and messages location
In-Reply-To: <20130527061154.GA3301@cskk.homeip.net>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
Message-ID: <knvggn$sjn$1@ger.gmane.org>

On 27/05/2013 07:11, Cameron Simpson wrote:
>
> BTW, I recommend importing "errno" and using symbolic names. It makes things much more readable, and accomodates the situation where the symbols map to different numbers on different platforms. And have a catch-all. For example:
>
> Cheers,
>

This should make life easier for us 
http://docs.python.org/3/whatsnew/3.3.html#pep-3151-reworking-the-os-and-io-exception-hierarchy

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From fabiosantosart at gmail.com  Mon May 27 08:46:50 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 27 May 2013 13:46:50 +0100
Subject: Python error codes and messages location
In-Reply-To: <knvggn$sjn$1@ger.gmane.org>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
Message-ID: <CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>

On 27 May 2013 12:41, "Mark Lawrence" <breamoreboy at yahoo.co.uk> wrote:
> This should make life easier for us
http://docs.python.org/3/whatsnew/3.3.html#pep-3151-reworking-the-os-and-io-exception-hierarchy

Speaking of PEPs and exceptions. When do we get localized exceptions?
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From vito.detullio at gmail.com  Mon May 27 14:19:33 2013
From: vito.detullio at gmail.com (Vito De Tullio)
Date: Mon, 27 May 2013 20:19:33 +0200
Subject: Python error codes and messages location
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
Message-ID: <ko083m$udv$1@ger.gmane.org>

F?bio Santos wrote:

>> This should make life easier for us
> http://docs.python.org/3/whatsnew/3.3.html#pep-3151-reworking-the-os-and-io-exception-hierarchy
> 
> Speaking of PEPs and exceptions. When do we get localized exceptions?

What do you mean by "localized exceptions"?

Please, tell me it's *NOT* a proposal to send the exception message in the 
locale language!

-- 
By ZeD



From fabiosantosart at gmail.com  Mon May 27 14:36:26 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 27 May 2013 19:36:26 +0100
Subject: Python error codes and messages location
In-Reply-To: <ko083m$udv$1@ger.gmane.org>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
Message-ID: <CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>

On 27 May 2013 19:23, "Vito De Tullio" <vito.detullio at gmail.com> wrote:
>
> F?bio Santos wrote:
>
> >> This should make life easier for us
> >
http://docs.python.org/3/whatsnew/3.3.html#pep-3151-reworking-the-os-and-io-exception-hierarchy
> >
> > Speaking of PEPs and exceptions. When do we get localized exceptions?
>
> What do you mean by "localized exceptions"?
>
> Please, tell me it's *NOT* a proposal to send the exception message in the
> locale language!
>
> --
> By ZeD
>
> --
> http://mail.python.org/mailman/listinfo/python-list

It is. I think I read it mentioned in python-dev or this list.
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From fabiosantosart at gmail.com  Mon May 27 19:44:22 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 28 May 2013 00:44:22 +0100
Subject: Python error codes and messages location
In-Reply-To: <CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
Message-ID: <CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>

On 27 May 2013 19:36, "F?bio Santos" <fabiosantosart at gmail.com> wrote:
>
>
> On 27 May 2013 19:23, "Vito De Tullio" <vito.detullio at gmail.com> wrote:
> >
> > F?bio Santos wrote:
> >
> > >> This should make life easier for us
> > >
http://docs.python.org/3/whatsnew/3.3.html#pep-3151-reworking-the-os-and-io-exception-hierarchy
> > >
> > > Speaking of PEPs and exceptions. When do we get localized exceptions?
> >
> > What do you mean by "localized exceptions"?
> >
> > Please, tell me it's *NOT* a proposal to send the exception message in
the
> > locale language!
> >
> > --
> > By ZeD
> >
> > --
> > http://mail.python.org/mailman/listinfo/python-list
>
> It is. I think I read it mentioned in python-dev or this list.

Here is what I read.

http://mail.python.org/pipermail/python-dev/2013-April/125364.html

It wasn't only about exceptions after all. And it seems like something that
will only happen far into the future.
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From vito.detullio at gmail.com  Tue May 28 00:13:18 2013
From: vito.detullio at gmail.com (Vito De Tullio)
Date: Tue, 28 May 2013 06:13:18 +0200
Subject: Python error codes and messages location
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
	<CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>
Message-ID: <ko1asv$tgg$1@ger.gmane.org>

F?bio Santos wrote:

>> > > Speaking of PEPs and exceptions. When do we get localized exceptions?
>> >
>> > What do you mean by "localized exceptions"?
>> >
>> > Please, tell me it's *NOT* a proposal to send the exception message in
>> > the
>> > locale language!
>> It is. I think I read it mentioned in python-dev or this list.
> 
> Here is what I read.
> 
> http://mail.python.org/pipermail/python-dev/2013-April/125364.html
> 
> It wasn't only about exceptions after all. And it seems like something
> that will only happen far into the future.

I really hope really far... have you never tried to google a localized error 
message? :\

-- 
By ZeD



From fabiosantosart at gmail.com  Tue May 28 02:57:14 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 28 May 2013 07:57:14 +0100
Subject: Python error codes and messages location
In-Reply-To: <ko1asv$tgg$1@ger.gmane.org>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
	<CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>
	<ko1asv$tgg$1@ger.gmane.org>
Message-ID: <CAA=1kxSmg3r=wL3acL0fFD8E+G1OzPWYySdLco25Ex91oLkfPQ@mail.gmail.com>

On 28 May 2013 05:17, "Vito De Tullio" <vito.detullio at gmail.com> wrote:
>
> F?bio Santos wrote:
>
> >> > > Speaking of PEPs and exceptions. When do we get localized
exceptions?
> >> >
> >> > What do you mean by "localized exceptions"?
> >> >
> >> > Please, tell me it's *NOT* a proposal to send the exception message
in
> >> > the
> >> > locale language!
> >> It is. I think I read it mentioned in python-dev or this list.
> >
> > Here is what I read.
> >
> > http://mail.python.org/pipermail/python-dev/2013-April/125364.html
> >
> > It wasn't only about exceptions after all. And it seems like something
> > that will only happen far into the future.
>
> I really hope really far... have you never tried to google a localized
error
> message? :\
>
> --
> By ZeD
>

Never. I don't even try.

I still think this is a good idea. Not for debugging though.

For UI (and error logs if your requirements include writing them in the
user language), it could simplify all the
user-facing-unexpected-error-reporting into an except hook, or a
try..except high up in your call stack.

It would be a pretty big step towards RAD. But it had to be made optional
somehow.

Maybe using errno and existing exception messages together with gettext?
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From rosuav at gmail.com  Tue May 28 03:15:51 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 28 May 2013 17:15:51 +1000
Subject: Python error codes and messages location
In-Reply-To: <CAA=1kxSmg3r=wL3acL0fFD8E+G1OzPWYySdLco25Ex91oLkfPQ@mail.gmail.com>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
	<CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>
	<ko1asv$tgg$1@ger.gmane.org>
	<CAA=1kxSmg3r=wL3acL0fFD8E+G1OzPWYySdLco25Ex91oLkfPQ@mail.gmail.com>
Message-ID: <CAPTjJmpeq1Wq8-+11eiwZjwnYApHubMeNSBRW3yynFyWNQw87w@mail.gmail.com>

On Tue, May 28, 2013 at 4:57 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
>
> On 28 May 2013 05:17, "Vito De Tullio" <vito.detullio at gmail.com> wrote:
>> I really hope really far... have you never tried to google a localized
>> error
>> message? :\
>
> Never. I don't even try.

Same happens when someone pastes an error onto a mailing list like
this. Unless there's some easily-identifiable token (maybe the
exception type doesn't get localized, though that has its own
consequences) by which everyone world-over can recognize the
exception, this would be a major nuisance. Also, once the interpreter
core and a few parts of the stdlib get localized, this would add a
barrier to entry for new modules... not sure this is a good thing.

Can we internationalize English instead of localizing Python?

Not-entirely-joking-ly yours,

ChrisA


From fabiosantosart at gmail.com  Tue May 28 04:10:51 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 28 May 2013 09:10:51 +0100
Subject: Python error codes and messages location
In-Reply-To: <CAPTjJmpeq1Wq8-+11eiwZjwnYApHubMeNSBRW3yynFyWNQw87w@mail.gmail.com>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
	<CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>
	<ko1asv$tgg$1@ger.gmane.org>
	<CAA=1kxSmg3r=wL3acL0fFD8E+G1OzPWYySdLco25Ex91oLkfPQ@mail.gmail.com>
	<CAPTjJmpeq1Wq8-+11eiwZjwnYApHubMeNSBRW3yynFyWNQw87w@mail.gmail.com>
Message-ID: <CAA=1kxQHTLe7vwXfSQx_oaFkDJy1wqpdQzu2=BZeGpPNimMPmA@mail.gmail.com>

On 28 May 2013 08:19, "Chris Angelico" <rosuav at gmail.com> wrote:
>
> On Tue, May 28, 2013 at 4:57 PM, F?bio Santos <fabiosantosart at gmail.com>
wrote:
> >
> > On 28 May 2013 05:17, "Vito De Tullio" <vito.detullio at gmail.com> wrote:
> >> I really hope really far... have you never tried to google a localized
> >> error
> >> message? :\
> >
> > Never. I don't even try.
>
> Same happens when someone pastes an error onto a mailing list like
> this. Unless there's some easily-identifiable token (maybe the
> exception type doesn't get localized, though that has its own
> consequences) by which everyone world-over can recognize the
> exception, this would be a major nuisance.

Just to clarify, I am suggesting to have the unchanged messages in
tracebacks, but having some methods in the exception to get the exception
and message localised. Just like repr() and str() are directed at different
audiences (the programmer vs. The user), so is a traceback vs a message box.

In English, we could "translate" the exception name (which is limited as a
python name). EG. RuntimeError -> Runtime error. Of course, this is not a
big deal, but it would let us show the error message to the user, together
with the exception.

It would be much harder to search for an error or ask for help if it was a
message written by some random developer.

OpenERP for example shows stack traces to the user. It could show a shorter
message in the user's language.

> Also, once the interpreter
> core and a few parts of the stdlib get localized, this would add a
> barrier to entry for new modules... not sure this is a good thing.

I think that would be a job for a per-language team as opposed to someone
implementing a bug fix or pushing a PEP? Even that would only be necessary
for the exceptions a module raises.

> Can we internationalize English instead of localizing Python?
>

That is worse than saying, "why don't we all just code in python?". Or c.
Or java. Or JavaScript.

Let's not get into that. I prefer len() to new
LengthCalculatorFactoryBuilder().createLengthCalculatorFactory().createLengthCalculator().calculateLengthOf().
And a good old Python list or JavaScript array to a collection of segfaults.
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From rosuav at gmail.com  Tue May 28 04:17:54 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 28 May 2013 18:17:54 +1000
Subject: Python error codes and messages location
In-Reply-To: <CAA=1kxQHTLe7vwXfSQx_oaFkDJy1wqpdQzu2=BZeGpPNimMPmA@mail.gmail.com>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
	<CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>
	<ko1asv$tgg$1@ger.gmane.org>
	<CAA=1kxSmg3r=wL3acL0fFD8E+G1OzPWYySdLco25Ex91oLkfPQ@mail.gmail.com>
	<CAPTjJmpeq1Wq8-+11eiwZjwnYApHubMeNSBRW3yynFyWNQw87w@mail.gmail.com>
	<CAA=1kxQHTLe7vwXfSQx_oaFkDJy1wqpdQzu2=BZeGpPNimMPmA@mail.gmail.com>
Message-ID: <CAPTjJmopdEXydmO6oGpm0RzoPUPKaX8DBzXvcpOs5sc1uwqH3A@mail.gmail.com>

On Tue, May 28, 2013 at 6:10 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
> Just to clarify, I am suggesting to have the unchanged messages in
> tracebacks, but having some methods in the exception to get the exception
> and message localised. Just like repr() and str() are directed at different
> audiences (the programmer vs. The user), so is a traceback vs a message box.

There's no particular reason for that to be a method on the exception,
then. You're just asking to localize a text string, and I think that
functionality already exists someplace :)

> OpenERP for example shows stack traces to the user. It could show a shorter
> message in the user's language.

Sounds like an OpenERP feature request, then.

> On 28 May 2013 08:19, "Chris Angelico" <rosuav at gmail.com> wrote:
>> Can we internationalize English instead of localizing Python?
>>
>
> That is worse than saying, "why don't we all just code in python?". Or c. Or
> java. Or JavaScript.
>
> Let's not get into that. I prefer len() to new
> LengthCalculatorFactoryBuilder().createLengthCalculatorFactory().createLengthCalculator().calculateLengthOf().
> And a good old Python list or JavaScript array to a collection of segfaults.

Yeah, like I said, that wasn't a serious suggestion :)

ChrisA


From storchaka at gmail.com  Tue May 28 09:11:54 2013
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Tue, 28 May 2013 16:11:54 +0300
Subject: Python error codes and messages location
In-Reply-To: <CAPTjJmopdEXydmO6oGpm0RzoPUPKaX8DBzXvcpOs5sc1uwqH3A@mail.gmail.com>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
	<CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>
	<ko1asv$tgg$1@ger.gmane.org>
	<CAA=1kxSmg3r=wL3acL0fFD8E+G1OzPWYySdLco25Ex91oLkfPQ@mail.gmail.com>
	<CAPTjJmpeq1Wq8-+11eiwZjwnYApHubMeNSBRW3yynFyWNQw87w@mail.gmail.com>
	<CAA=1kxQHTLe7vwXfSQx_oaFkDJy1wqpdQzu2=BZeGpPNimMPmA@mail.gmail.com>
	<CAPTjJmopdEXydmO6oGpm0RzoPUPKaX8DBzXvcpOs5sc1uwqH3A@mail.gmail.com>
Message-ID: <ko2ael$r4o$2@ger.gmane.org>

28.05.13 11:17, Chris Angelico ???????(??):
> On Tue, May 28, 2013 at 6:10 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
>> Just to clarify, I am suggesting to have the unchanged messages in
>> tracebacks, but having some methods in the exception to get the exception
>> and message localised. Just like repr() and str() are directed at different
>> audiences (the programmer vs. The user), so is a traceback vs a message box.
>
> There's no particular reason for that to be a method on the exception,
> then. You're just asking to localize a text string, and I think that
> functionality already exists someplace :)

It will be very helpful in case of KeyError for example.




From fabiosantosart at gmail.com  Tue May 28 11:26:01 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 28 May 2013 16:26:01 +0100
Subject: Python error codes and messages location
In-Reply-To: <CAPTjJmopdEXydmO6oGpm0RzoPUPKaX8DBzXvcpOs5sc1uwqH3A@mail.gmail.com>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
	<CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>
	<ko1asv$tgg$1@ger.gmane.org>
	<CAA=1kxSmg3r=wL3acL0fFD8E+G1OzPWYySdLco25Ex91oLkfPQ@mail.gmail.com>
	<CAPTjJmpeq1Wq8-+11eiwZjwnYApHubMeNSBRW3yynFyWNQw87w@mail.gmail.com>
	<CAA=1kxQHTLe7vwXfSQx_oaFkDJy1wqpdQzu2=BZeGpPNimMPmA@mail.gmail.com>
	<CAPTjJmopdEXydmO6oGpm0RzoPUPKaX8DBzXvcpOs5sc1uwqH3A@mail.gmail.com>
Message-ID: <CAA=1kxRB_G7qkRPwQOpcq6G=c4TjSQ8DSuroTcNwsAK1V_UZ1g@mail.gmail.com>

On 28 May 2013 09:22, "Chris Angelico" <rosuav at gmail.com> wrote:
>
> On Tue, May 28, 2013 at 6:10 PM, F?bio Santos <fabiosantosart at gmail.com>
wrote:
> > Just to clarify, I am suggesting to have the unchanged messages in
> > tracebacks, but having some methods in the exception to get the
exception
> > and message localised. Just like repr() and str() are directed at
different
> > audiences (the programmer vs. The user), so is a traceback vs a message
box.
>
> There's no particular reason for that to be a method on the exception,
> then. You're just asking to localize a text string, and I think that
> functionality already exists someplace :)

Yes :) what we don't have is a translation string for every exception that
Python could raise. Or at least some of them.

> > OpenERP for example shows stack traces to the user. It could show a
shorter
> > message in the user's language.
>
> Sounds like an OpenERP feature request, then.

No, it's just something that OpenERP would obviously do if it had a library
to, or language support :) this could be the One Obvious Way To Do It for
displaying error messages in localised applications.

That said, I'm going to think about this and maybe write a library for
localising exceptions and a portuguese translation pack.

PS. FWIW I'm rather stubborn sometimes. Sorry if I bothered you in any way.
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From fabiosantosart at gmail.com  Wed May 29 02:45:42 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Wed, 29 May 2013 07:45:42 +0100
Subject: Python error codes and messages location
In-Reply-To: <5vfaq8tfcoigfij2og8hinr7inlvahssdm@invalid.netcom.com>
References: <20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
	<CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>
	<ko1asv$tgg$1@ger.gmane.org>
	<CAA=1kxSmg3r=wL3acL0fFD8E+G1OzPWYySdLco25Ex91oLkfPQ@mail.gmail.com>
	<CAPTjJmpeq1Wq8-+11eiwZjwnYApHubMeNSBRW3yynFyWNQw87w@mail.gmail.com>
	<5vfaq8tfcoigfij2og8hinr7inlvahssdm@invalid.netcom.com>
Message-ID: <CAA=1kxSqCPTjRYXTuGPOia2n54Bv_wUtOCmMZ1r05DBsLi1hMQ@mail.gmail.com>

On 29 May 2013 00:44, "Dennis Lee Bieber" <wlfraed at ix.netcom.com> wrote:
>
> On Tue, 28 May 2013 17:15:51 +1000, Chris Angelico <rosuav at gmail.com>
> declaimed the following in gmane.comp.python.general:
>
>
> > Can we internationalize English instead of localizing Python?
> >
> > Not-entirely-joking-ly yours,
> >
>         All that is required is to get Python declared a valid air traffic
> control communication (all international air traffic control uses
> English)
>
> Totally-joking-I-suspect
>
> --
>         Wulfraed                 Dennis Lee Bieber         AF6VN
>         wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/
>

with import mangoes as cargo:
     allow()
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From steve+comp.lang.python at pearwood.info  Tue May 28 04:38:35 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 28 May 2013 08:38:35 GMT
Subject: Python error codes and messages location
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net> <knvggn$sjn$1@ger.gmane.org>
	<CAA=1kxTjywHHbUeRbpJS86vh5r0toAhvMghLNLh+xbsYzYu9Sg@mail.gmail.com>
	<ko083m$udv$1@ger.gmane.org>
	<CAA=1kxT7AAMJcm9hokgtisFSjMi_5v=w+zesh-i2VgaYFochKg@mail.gmail.com>
	<CAA=1kxTucYUr0++Y10y3npj2MSnLtQ6MvAsaS3SkqF4U3Bbnpw@mail.gmail.com>
	<ko1asv$tgg$1@ger.gmane.org>
	<CAA=1kxSmg3r=wL3acL0fFD8E+G1OzPWYySdLco25Ex91oLkfPQ@mail.gmail.com>
	<mailman.2285.1369725359.3114.python-list@python.org>
Message-ID: <51a46d0b$0$11118$c3e8da3@news.astraweb.com>

On Tue, 28 May 2013 17:15:51 +1000, Chris Angelico wrote:

> Can we internationalize English instead of localizing Python?

We have. English is the primary international language for programmers. 
(For which I am profoundly grateful.)

Japanese is also a pretty important language, but mostly in Japan. And 
China would like Chinese to be, in fact there is even a version of Python 
localised to Chinese:

http://www.chinesepython.org/


I have no objection to people creating their own, localised, 
implementation or fork of Python, in which case good luck to them but 
they're on their own. But I don't think that exceptions should otherwise 
be localised.



-- 
Steven


From steve+comp.lang.python at pearwood.info  Mon May 27 09:11:46 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 27 May 2013 13:11:46 GMT
Subject: Python error codes and messages location
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net> <knvggn$sjn$1@ger.gmane.org>
	<mailman.2248.1369658818.3114.python-list@python.org>
Message-ID: <51a35b92$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Mon, 27 May 2013 13:46:50 +0100, F?bio Santos wrote:

> Speaking of PEPs and exceptions. When do we get localized exceptions? 


We're waiting for you to volunteer. When can you start?


-- 
Steven


From fabiosantosart at gmail.com  Mon May 27 09:26:01 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Mon, 27 May 2013 14:26:01 +0100
Subject: Python error codes and messages location
In-Reply-To: <51a35b92$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>
	<20130527061154.GA3301@cskk.homeip.net>
	<knvggn$sjn$1@ger.gmane.org>
	<mailman.2248.1369658818.3114.python-list@python.org>
	<51a35b92$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAA=1kxR=05RbcbR8s1rzfdQBGXGRRx2j=O8NpcEFB-_GiZBJPg@mail.gmail.com>

On Mon, May 27, 2013 at 2:11 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Mon, 27 May 2013 13:46:50 +0100, F?bio Santos wrote:
>
>> Speaking of PEPs and exceptions. When do we get localized exceptions?
>
>
> We're waiting for you to volunteer. When can you start?

I'd love to work on that but my C is too shabby to say the least.

--
F?bio Santos


From carlosnepomuceno at outlook.com  Mon May 27 12:54:59 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Mon, 27 May 2013 19:54:59 +0300
Subject: Python error codes and messages location
In-Reply-To: <CAA=1kxR=05RbcbR8s1rzfdQBGXGRRx2j=O8NpcEFB-_GiZBJPg@mail.gmail.com>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>,
	<20130527061154.GA3301@cskk.homeip.net>,
	<knvggn$sjn$1@ger.gmane.org>,
	<mailman.2248.1369658818.3114.python-list@python.org>,
	<51a35b92$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<CAA=1kxR=05RbcbR8s1rzfdQBGXGRRx2j=O8NpcEFB-_GiZBJPg@mail.gmail.com>
Message-ID: <BLU176-W1180C2F2FA4801E4EB5FEBD7960@phx.gbl>

Thanks so much guys!

I'm not planning to prepare for every possible situation, but I certainly am responsible to handle most common errors. So it's really important to know what a function/method returns when called.

Exception handling may take lots of code, but I'm used to it. It's much better to have a graceful shutdown than a data/time loss. ;)

I think PEP 3151 is a step ahead! That's almost exactly what I was looking for. Why did it take so long to have that implemented? 		 	   		  

From breamoreboy at yahoo.co.uk  Mon May 27 13:14:21 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 27 May 2013 18:14:21 +0100
Subject: Python error codes and messages location
In-Reply-To: <BLU176-W1180C2F2FA4801E4EB5FEBD7960@phx.gbl>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>,
	<20130527061154.GA3301@cskk.homeip.net>,
	<knvggn$sjn$1@ger.gmane.org>,
	<mailman.2248.1369658818.3114.python-list@python.org>,
	<51a35b92$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<CAA=1kxR=05RbcbR8s1rzfdQBGXGRRx2j=O8NpcEFB-_GiZBJPg@mail.gmail.com>
	<BLU176-W1180C2F2FA4801E4EB5FEBD7960@phx.gbl>
Message-ID: <ko048j$kte$1@ger.gmane.org>

On 27/05/2013 17:54, Carlos Nepomuceno wrote:
>
> I think PEP 3151 is a step ahead! That's almost exactly what I was looking for. Why did it take so long to have that implemented? 		 	   		
>

Lack of volunteers.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From tjreedy at udel.edu  Mon May 27 13:52:42 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Mon, 27 May 2013 13:52:42 -0400
Subject: Python error codes and messages location
In-Reply-To: <BLU176-W1180C2F2FA4801E4EB5FEBD7960@phx.gbl>
References: <BLU176-W2F86295ACD2E1CD29375BD7960@phx.gbl>,
	<20130527061154.GA3301@cskk.homeip.net>,
	<knvggn$sjn$1@ger.gmane.org>,
	<mailman.2248.1369658818.3114.python-list@python.org>,
	<51a35b92$0$30002$c3e8da3$5496439d@news.astraweb.com>,
	<CAA=1kxR=05RbcbR8s1rzfdQBGXGRRx2j=O8NpcEFB-_GiZBJPg@mail.gmail.com>
	<BLU176-W1180C2F2FA4801E4EB5FEBD7960@phx.gbl>
Message-ID: <ko06gr$e48$1@ger.gmane.org>

On 5/27/2013 12:54 PM, Carlos Nepomuceno wrote:

> I think PEP 3151 is a step ahead! That's almost exactly what I was looking for. Why did it take so long to have that implemented? 		 	   		

Since this PEP involved changing existing features, rather than adding 
something mew, it probably took moe time and discussion to get consensus 
on details of the change.



From cs at zip.com.au  Sun May 26 22:02:41 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 27 May 2013 12:02:41 +1000
Subject: Python error codes and messages location
In-Reply-To: <51a2ae95$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <51a2ae95$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20130527020241.GA85366@cskk.homeip.net>

On 27May2013 00:53, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
| On Mon, 27 May 2013 02:13:54 +0300, Carlos Nepomuceno wrote:
| > Where can I find all error codes and messages that Python throws (actual
| > codes and messages from exceptions raised by stdlib)?
| 
| There is no list. It is subject to change from version to version, 
| including point releases.

And better still, it is platform specific too.

[...]
| > I've already found the module 'errno' and got a dictionary
| > (errno.errorcode) and some system error messages
| > (os.strerror(errno.ENAMETOOLONG)) but there's more I couldn't find.
| 
| These are the standard C operating system and file system error codes, 
| not Python exceptions.

And the poster boy example for platform dependence.

Besides, knowing the exact errors that may occur is not the Python Way, it is
the Java Way.

Run it. if it goes bang, handle the errors you expect and understand.
If you get something else, go bang for real because you _don't_
know what should happen, and proceeding is probably insane.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Motorcycles are like peanuts... who can stop at just one?
- Zebee Johnstone <zebee at zip.com.au> aus.motorcycles Poser Permit #1


From avnesh.nitk at gmail.com  Mon May 27 00:32:40 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Sun, 26 May 2013 21:32:40 -0700 (PDT)
Subject: how to compare two json file line by line using python?
Message-ID: <355f934e-bda0-4316-96bb-583c498ecb1a@googlegroups.com>

hi,
   how to compare two json file line by line using python? Actually I am doing it in this way..

import simplejson as json
def compare():
    newJsonFile= open('newData.json')
    lastJsonFile= open('version1.json')
    newLines = newJsonFile.readlines()
    print newLines
    sortedNew = sorted([repr(x) for x in newJsonFile])
    sortedLast = sorted([repr(x) for x in lastJsonFile])
    print(sortedNew == sortedLast)

compare()

But I want to compare line by line and value by value. but i found that json data is unordered data, so how can i compare them without sorting it. please give me some idea about it. I am new for it.
I want to check every value line by line.

Thanks


From rustompmody at gmail.com  Mon May 27 00:51:59 2013
From: rustompmody at gmail.com (rusi)
Date: Sun, 26 May 2013 21:51:59 -0700 (PDT)
Subject: how to compare two json file line by line using python?
References: <355f934e-bda0-4316-96bb-583c498ecb1a@googlegroups.com>
Message-ID: <bb5d992b-4592-4777-ae47-3b3e090703a1@d8g2000pbe.googlegroups.com>

On May 27, 9:32?am, Avnesh Shakya <avnesh.n... at gmail.com> wrote:
> hi,
> ? ?how to compare two json file line by line using python? Actually I am doing it in this way..
>
> import simplejson as json
> def compare():
> ? ? newJsonFile= open('newData.json')
> ? ? lastJsonFile= open('version1.json')
> ? ? newLines = newJsonFile.readlines()
> ? ? print newLines
> ? ? sortedNew = sorted([repr(x) for x in newJsonFile])
> ? ? sortedLast = sorted([repr(x) for x in lastJsonFile])
> ? ? print(sortedNew == sortedLast)
>
> compare()
>
> But I want to compare line by line and value by value. but i found that json data is unordered data, so how can i compare them without sorting it. please give me some idea about it. I am new for it.
> I want to check every value line by line.
>
> Thanks

It really depends on what is your notion that the two files are same
or not.

For example does extra/deleted non-significant white-space matter?

By and large there are two approaches:
1. Treat json as serialized python data-structures, (and so) read in
the data-structures into python and compare there

2. Ignore the fact that the json file is a json file; just treat it as
text and use string compare operations

Naturally there could be other considerations: the files could be huge
and so you might want some hybrid of json and text approaches
etc etc


From avnesh.nitk at gmail.com  Mon May 27 01:05:39 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Mon, 27 May 2013 10:35:39 +0530
Subject: how to compare two json file line by line using python?
In-Reply-To: <bb5d992b-4592-4777-ae47-3b3e090703a1@d8g2000pbe.googlegroups.com>
References: <355f934e-bda0-4316-96bb-583c498ecb1a@googlegroups.com>
	<bb5d992b-4592-4777-ae47-3b3e090703a1@d8g2000pbe.googlegroups.com>
Message-ID: <CAEA17EK16ETu_HxqfB48mxyTdJN5jUxF0FfBkEMu9bQM7o25XA@mail.gmail.com>

Actually, I am extracting data from other site in json format and I want to
put it in my database and when I extract data again then I want to compare
last json file, if these are same then no issue otherwise i will add new
data in database, so here may be every time data can be changed or may be
not so I think sorting is required, but if i compare line by line that will
be good, I am thinking in this way...


On Mon, May 27, 2013 at 10:21 AM, rusi <rustompmody at gmail.com> wrote:

> On May 27, 9:32 am, Avnesh Shakya <avnesh.n... at gmail.com> wrote:
> > hi,
> >    how to compare two json file line by line using python? Actually I am
> doing it in this way..
> >
> > import simplejson as json
> > def compare():
> >     newJsonFile= open('newData.json')
> >     lastJsonFile= open('version1.json')
> >     newLines = newJsonFile.readlines()
> >     print newLines
> >     sortedNew = sorted([repr(x) for x in newJsonFile])
> >     sortedLast = sorted([repr(x) for x in lastJsonFile])
> >     print(sortedNew == sortedLast)
> >
> > compare()
> >
> > But I want to compare line by line and value by value. but i found that
> json data is unordered data, so how can i compare them without sorting it.
> please give me some idea about it. I am new for it.
> > I want to check every value line by line.
> >
> > Thanks
>
> It really depends on what is your notion that the two files are same
> or not.
>
> For example does extra/deleted non-significant white-space matter?
>
> By and large there are two approaches:
> 1. Treat json as serialized python data-structures, (and so) read in
> the data-structures into python and compare there
>
> 2. Ignore the fact that the json file is a json file; just treat it as
> text and use string compare operations
>
> Naturally there could be other considerations: the files could be huge
> and so you might want some hybrid of json and text approaches
> etc etc
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From steve+comp.lang.python at pearwood.info  Mon May 27 01:33:11 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 27 May 2013 05:33:11 GMT
Subject: how to compare two json file line by line using python?
References: <355f934e-bda0-4316-96bb-583c498ecb1a@googlegroups.com>
Message-ID: <51a2f016$0$1744$c3e8da3$76491128@news.astraweb.com>

On Sun, 26 May 2013 21:32:40 -0700, Avnesh Shakya wrote:

> But I want to compare line by line and value by value. but i found that
> json data is unordered data, so how can i compare them without sorting
> it. please give me some idea about it. I am new for it. I want to check
> every value line by line.

Why do you care about checking every value line by line? As you say 
yourself, JSON data is unordered, so "line by line" is the wrong way to 
compare it.


The right way is to decode the JSON data, and then compare whether it 
gives you the result you expect:

a = json.load("file-a")
b = json.load("file-b")
if a == b:
    print("file-a and file-b contain the same JSON data")

If what you care about is the *data* stored in the JSON file, this is the 
correct way to check it.

On the other hand, if you don't care about the data, but you want to 
detect changes to whitespace, blank lines, or other changes that make no 
difference to the JSON data, then there is no need to care that this is 
JSON data. Just treat it as text, and use the difflib library.

http://docs.python.org/2/library/difflib.html


-- 
Steven


From avnesh.nitk at gmail.com  Mon May 27 02:28:42 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Mon, 27 May 2013 11:58:42 +0530
Subject: how to compare two json file line by line using python?
In-Reply-To: <51a2f016$0$1744$c3e8da3$76491128@news.astraweb.com>
References: <355f934e-bda0-4316-96bb-583c498ecb1a@googlegroups.com>
	<51a2f016$0$1744$c3e8da3$76491128@news.astraweb.com>
Message-ID: <CAEA17EKVV8pLQBvThc14_ZaKQfurgk9zb5X82UvaM45HFyzt6A@mail.gmail.com>

Thanks a lot, I got it.


On Mon, May 27, 2013 at 11:03 AM, Steven D'Aprano <
steve+comp.lang.python at pearwood.info> wrote:

> On Sun, 26 May 2013 21:32:40 -0700, Avnesh Shakya wrote:
>
> > But I want to compare line by line and value by value. but i found that
> > json data is unordered data, so how can i compare them without sorting
> > it. please give me some idea about it. I am new for it. I want to check
> > every value line by line.
>
> Why do you care about checking every value line by line? As you say
> yourself, JSON data is unordered, so "line by line" is the wrong way to
> compare it.
>
>
> The right way is to decode the JSON data, and then compare whether it
> gives you the result you expect:
>
> a = json.load("file-a")
> b = json.load("file-b")
> if a == b:
>     print("file-a and file-b contain the same JSON data")
>
> If what you care about is the *data* stored in the JSON file, this is the
> correct way to check it.
>
> On the other hand, if you don't care about the data, but you want to
> detect changes to whitespace, blank lines, or other changes that make no
> difference to the JSON data, then there is no need to care that this is
> JSON data. Just treat it as text, and use the difflib library.
>
> http://docs.python.org/2/library/difflib.html
>
>
> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From invalid at invalid.invalid  Tue May 28 12:00:14 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 16:00:14 +0000 (UTC)
Subject: how to compare two json file line by line using python?
References: <355f934e-bda0-4316-96bb-583c498ecb1a@googlegroups.com>
	<51a2f016$0$1744$c3e8da3$76491128@news.astraweb.com>
Message-ID: <ko2kae$9oh$3@reader1.panix.com>

On 2013-05-27, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> On Sun, 26 May 2013 21:32:40 -0700, Avnesh Shakya wrote:
>
>> But I want to compare line by line and value by value. but i found that
>> json data is unordered data, so how can i compare them without sorting
>> it. please give me some idea about it. I am new for it. I want to check
>> every value line by line.
>
> Why do you care about checking every value line by line? As you say 
> yourself, JSON data is unordered, so "line by line" is the wrong way to 
> compare it.

There's no such thing as "lines" in JSON anyway. Outside of string
literals, all whitespace is equivalent, so replacing all newlines with
space characters results in equivalent blobs of JSON -- but one is a
single line, and the other is multiple lines.

> The right way is to decode the JSON data, and then compare whether it 
> gives you the result you expect:
>
> a = json.load("file-a")
> b = json.load("file-b")
> if a == b:
>     print("file-a and file-b contain the same JSON data")
>
> If what you care about is the *data* stored in the JSON file, this is
> the correct way to check it.

Yup.

-- 
Grant Edwards               grant.b.edwards        Yow! Are we laid back yet?
                                  at               
                              gmail.com            


From denismfmcmahon at gmail.com  Mon May 27 06:50:16 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Mon, 27 May 2013 10:50:16 +0000 (UTC)
Subject: how to compare two json file line by line using python?
References: <355f934e-bda0-4316-96bb-583c498ecb1a@googlegroups.com>
Message-ID: <knvdp8$gvn$4@dont-email.me>

On Sun, 26 May 2013 21:32:40 -0700, Avnesh Shakya wrote:

>    how to compare two json file line by line using python? Actually I am
>    doing it in this way..

Oh what a lot of homework you have today.

Did you ever stop to think what the easiest way to compare two json 
datasets is?

-- 
Denis McMahon, denismfmcmahon at gmail.com


From lokeshkoppaka at gmail.com  Mon May 27 00:48:34 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Sun, 26 May 2013 21:48:34 -0700 (PDT)
Subject: help?? on functions
Message-ID: <dcc5e15d-fc93-4ad7-9522-b5621d1bec44@googlegroups.com>

def shuffle(input, i, j):
    pass
    input = input[i:j+1] +input[0:i] + input[j+1:]
def test_shuffle():
    input = [1, 2, 3, 4, 5, 6]
    shuffle(input, 1, 2)
    assert [2, 3, 1, 4, 5, 6] == input


i had done the above code but the problem is i had manipulated the "input" in function shuffle(input, i, j) but once i get back to the test_shuffle() function again the variable "input" does not reflect the changes made in shuffle(input, i, j) why ,please can any one describe why . and help how to reflect that change to the variable "input".


From steve+comp.lang.python at pearwood.info  Mon May 27 01:48:34 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 27 May 2013 05:48:34 GMT
Subject: help?? on functions
References: <dcc5e15d-fc93-4ad7-9522-b5621d1bec44@googlegroups.com>
Message-ID: <51a2f3b2$0$1744$c3e8da3$76491128@news.astraweb.com>

On Sun, 26 May 2013 21:48:34 -0700, lokeshkoppaka wrote:

> def shuffle(input, i, j):
>     pass
>     input = input[i:j+1] +input[0:i] + input[j+1:]

"pass" does nothing. Take it out.



> def test_shuffle():
>     input = [1, 2, 3, 4, 5, 6]
>     shuffle(input, 1, 2)
>     assert [2, 3, 1, 4, 5, 6] == input
> 
> 
> i had done the above code but the problem is i had manipulated the
> "input" in function shuffle(input, i, j) but once i get back to the
> test_shuffle() function again the variable "input" does not reflect the
> changes made in shuffle(input, i, j) why ,please can any one describe
> why . and help how to reflect that change to the variable "input".

The line of code:

    input = input[i:j+1] +input[0:i] + input[j+1:]


takes the input list, makes three slices from that list, creates a new 
list, and then reassigns the LOCAL variable "input". This does not touch 
the variable on the outside of the function.

This will be more clear if you use different names:

# Outside the function.
mylist = [1, 2, 3, 4, 5, 6]
shuffle(mylist, 1, 2)


Inside the function "shuffle", "input" is a local variable, and when you 
reassign to it, the variable "mylist" on the outside is not changed. Try 
this small function to see what I mean:

def demo(input):
    print('local variable, before:', input)
    input = 100
    print('local variable, after:', input)
    print('non-local variable', mylist)


mylist = [1, 2, 3, 4, 5, 6]
demo(mylist)



So, what can you do to fix this? You have two choices:


1) You can return the shuffled list. Add this line to the end of your 
shuffle function:

    return input


and then inside the test function, do this:

def test_shuffle():
    input = [1, 2, 3, 4, 5, 6]
    input = shuffle(input, 1, 2)
    assert [2, 3, 1, 4, 5, 6] == input


2) You can modify the input list in place.

In this case, instead of reassigning the local variable "input" with the 
new list, you simply tell Python to stuff the new list inside the 
original list. You do that with a slice:


    input[:] = input[i:j+1] + input[0:i] + input[j+1:]


That's a small difference from what you wrote, just three characters [:], 
but it makes a big difference in the effect. Instead of reassigning the 
local variable to the new list, it takes the existing list, and replaces 
each value inside it with the values taken from the new list. For example:


py> mylist = [100, 200, 300, 400, 500, 600]
py> mylist[3:5] = ['A', 'B', 'C']
py> mylist
[100, 200, 300, 'A', 'B', 'C', 600]

py> mylist[1:] = [99, 98, 97]
py> mylist
[100, 99, 98, 97]


Any questions?


-- 
Steven


From lokeshkoppaka at gmail.com  Mon May 27 03:20:47 2013
From: lokeshkoppaka at gmail.com (lokeshkoppaka at gmail.com)
Date: Mon, 27 May 2013 00:20:47 -0700 (PDT)
Subject: help?? on functions
In-Reply-To: <51a2f3b2$0$1744$c3e8da3$76491128@news.astraweb.com>
References: <dcc5e15d-fc93-4ad7-9522-b5621d1bec44@googlegroups.com>
	<51a2f3b2$0$1744$c3e8da3$76491128@news.astraweb.com>
Message-ID: <d4d9741a-7390-4461-b244-c0a83c153bdc@googlegroups.com>

On Monday, May 27, 2013 11:18:34 AM UTC+5:30, Steven D'Aprano wrote:
> On Sun, 26 May 2013 21:48:34 -0700, lokeshkoppaka wrote:
> 
> 
> 
> > def shuffle(input, i, j):
> 
> >     pass
> 
> >     input = input[i:j+1] +input[0:i] + input[j+1:]
> 
> 
> 
> "pass" does nothing. Take it out.
> 
> 
> 
> 
> 
> 
> 
> > def test_shuffle():
> 
> >     input = [1, 2, 3, 4, 5, 6]
> 
> >     shuffle(input, 1, 2)
> 
> >     assert [2, 3, 1, 4, 5, 6] == input
> 
> > 
> 
> > 
> 
> > i had done the above code but the problem is i had manipulated the
> 
> > "input" in function shuffle(input, i, j) but once i get back to the
> 
> > test_shuffle() function again the variable "input" does not reflect the
> 
> > changes made in shuffle(input, i, j) why ,please can any one describe
> 
> > why . and help how to reflect that change to the variable "input".
> 
> 
> 
> The line of code:
> 
> 
> 
>     input = input[i:j+1] +input[0:i] + input[j+1:]
> 
> 
> 
> 
> 
> takes the input list, makes three slices from that list, creates a new 
> 
> list, and then reassigns the LOCAL variable "input". This does not touch 
> 
> the variable on the outside of the function.
> 
> 
> 
> This will be more clear if you use different names:
> 
> 
> 
> # Outside the function.
> 
> mylist = [1, 2, 3, 4, 5, 6]
> 
> shuffle(mylist, 1, 2)
> 
> 
> 
> 
> 
> Inside the function "shuffle", "input" is a local variable, and when you 
> 
> reassign to it, the variable "mylist" on the outside is not changed. Try 
> 
> this small function to see what I mean:
> 
> 
> 
> def demo(input):
> 
>     print('local variable, before:', input)
> 
>     input = 100
> 
>     print('local variable, after:', input)
> 
>     print('non-local variable', mylist)
> 
> 
> 
> 
> 
> mylist = [1, 2, 3, 4, 5, 6]
> 
> demo(mylist)
> 
> 
> 
> 
> 
> 
> 
> So, what can you do to fix this? You have two choices:
> 
> 
> 
> 
> 
> 1) You can return the shuffled list. Add this line to the end of your 
> 
> shuffle function:
> 
> 
> 
>     return input
> 
> 
> 
> 
> 
> and then inside the test function, do this:
> 
> 
> 
> def test_shuffle():
> 
>     input = [1, 2, 3, 4, 5, 6]
> 
>     input = shuffle(input, 1, 2)
> 
>     assert [2, 3, 1, 4, 5, 6] == input
> 
> 
> 
> 
> 
> 2) You can modify the input list in place.
> 
> 
> 
> In this case, instead of reassigning the local variable "input" with the 
> 
> new list, you simply tell Python to stuff the new list inside the 
> 
> original list. You do that with a slice:
> 
> 
> 
> 
> 
>     input[:] = input[i:j+1] + input[0:i] + input[j+1:]
> 
> 
> 
> 
> 
> That's a small difference from what you wrote, just three characters [:], 
> 
> but it makes a big difference in the effect. Instead of reassigning the 
> 
> local variable to the new list, it takes the existing list, and replaces 
> 
> each value inside it with the values taken from the new list. For example:
> 
> 
> 
> 
> 
> py> mylist = [100, 200, 300, 400, 500, 600]
> 
> py> mylist[3:5] = ['A', 'B', 'C']
> 
> py> mylist
> 
> [100, 200, 300, 'A', 'B', 'C', 600]
> 
> 
> 
> py> mylist[1:] = [99, 98, 97]
> 
> py> mylist
> 
> [100, 99, 98, 97]
> 
> 
> 
> 
> 
> Any questions?
> 
> 
> 
> 
> 
> -- 
> 
> Steven

Steven 
wow, wonderful explanation ,i got it thanks a lot 


From john_ladasky at sbcglobal.net  Mon May 27 04:03:46 2013
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Mon, 27 May 2013 01:03:46 -0700 (PDT)
Subject: help?? on functions
In-Reply-To: <dcc5e15d-fc93-4ad7-9522-b5621d1bec44@googlegroups.com>
References: <dcc5e15d-fc93-4ad7-9522-b5621d1bec44@googlegroups.com>
Message-ID: <d0e1bae5-fca9-4723-97d1-68e55a06c944@googlegroups.com>

Steven gave you a lot of good advice.  Let me add just one remark.

Python already has a builtin function called "input."  If you define a variable with the same name as a builtin and then you try to use that builtin, you will be in for a (usually unpleasant) surprise.


From silusilusilu at gmail.com  Mon May 27 05:26:37 2013
From: silusilusilu at gmail.com (silusilusilu at gmail.com)
Date: Mon, 27 May 2013 02:26:37 -0700 (PDT)
Subject: Problems with python and pyQT
Message-ID: <8d8fd7fc-2509-457e-a4c9-0a1ac1f65c02@googlegroups.com>

Hi, 
i'm new with python: so excuse me for my questions....
i have this code:

    def updateLog(self, text):
        self.ui.logTextEdit.moveCursor(QTextCursor.End)
        self.ui.logTextEdit.insertHtml("<font color=\"Black\">"+text)
        self.ui.logTextEdit.moveCursor(QTextCursor.End)

logTextEdit is a QTextEdit object.With this code,i can display only ascii characters: how can i diplay text as hex and binary values?
Thanks


From kwpolska at gmail.com  Mon May 27 09:10:24 2013
From: kwpolska at gmail.com (=?UTF-8?B?Q2hyaXMg4oCcS3dwb2xza2HigJ0gV2Fycmljaw==?=)
Date: Mon, 27 May 2013 15:10:24 +0200
Subject: Problems with python and pyQT
In-Reply-To: <8d8fd7fc-2509-457e-a4c9-0a1ac1f65c02@googlegroups.com>
References: <8d8fd7fc-2509-457e-a4c9-0a1ac1f65c02@googlegroups.com>
Message-ID: <CAMw+j7KNj23-t82aBcouCzqcE6PfznMG79NdGBWOhJVuV_k7eA@mail.gmail.com>

On Mon, May 27, 2013 at 11:26 AM,  <silusilusilu at gmail.com> wrote:
> Hi,
> i'm new with python: so excuse me for my questions....
> i have this code:
>
>     def updateLog(self, text):
>         self.ui.logTextEdit.moveCursor(QTextCursor.End)
>         self.ui.logTextEdit.insertHtml("<font color=\"Black\">"+text)
>         self.ui.logTextEdit.moveCursor(QTextCursor.End)
>
> logTextEdit is a QTextEdit object.With this code,i can display only ascii characters: how can i diplay text as hex and binary values?
> Thanks
> --
> http://mail.python.org/mailman/listinfo/python-list

You would need to convert them to strings first.  You may want bin()
and hex() for that.  And if you want to convert 'q' to 0x71,
hex(ord("q")).  And if you want to turn 'hello' into 0x68656c6c6f, you
would need to iterate over 'hello' and run the above function over
every letter.

Also, you are able to display Unicode characters, too.

--
Kwpolska <http://kwpolska.tk> | GPG KEY: 5EAAEA16
stop html mail                | always bottom-post
http://asciiribbon.org        | http://caliburn.nl/topposting.html


From silusilusilu at gmail.com  Tue May 28 05:41:56 2013
From: silusilusilu at gmail.com (silusilusilu at gmail.com)
Date: Tue, 28 May 2013 02:41:56 -0700 (PDT)
Subject: Problems with python and pyQT
In-Reply-To: <mailman.2249.1369660253.3114.python-list@python.org>
References: <8d8fd7fc-2509-457e-a4c9-0a1ac1f65c02@googlegroups.com>
	<mailman.2249.1369660253.3114.python-list@python.org>
Message-ID: <646e6bae-b0fc-46fe-bf60-23ec9b4958a3@googlegroups.com>

Thanks for your reply: very useful!!
I have another question: with hex command i display (for example)

0x1

is it possible to display 0x01?
Thanks

Il giorno luned? 27 maggio 2013 15:10:24 UTC+2, Chris ?Kwpolska? Warrick ha scritto:
> On Mon, May 27, 2013 at 11:26 AM,  <silusilusilu at gmail.com> wrote:
> 
> > Hi,
> 
> > i'm new with python: so excuse me for my questions....
> 
> > i have this code:
> 
> >
> 
> >     def updateLog(self, text):
> 
> >         self.ui.logTextEdit.moveCursor(QTextCursor.End)
> 
> >         self.ui.logTextEdit.insertHtml("<font color=\"Black\">"+text)
> 
> >         self.ui.logTextEdit.moveCursor(QTextCursor.End)
> 
> >
> 
> > logTextEdit is a QTextEdit object.With this code,i can display only ascii characters: how can i diplay text as hex and binary values?
> 
> > Thanks
> 
> > --
> 
> > http://mail.python.org/mailman/listinfo/python-list
> 
> 
> 
> You would need to convert them to strings first.  You may want bin()
> 
> and hex() for that.  And if you want to convert 'q' to 0x71,
> 
> hex(ord("q")).  And if you want to turn 'hello' into 0x68656c6c6f, you
> 
> would need to iterate over 'hello' and run the above function over
> 
> every letter.
> 
> 
> 
> Also, you are able to display Unicode characters, too.




From davea at davea.name  Tue May 28 06:59:27 2013
From: davea at davea.name (Dave Angel)
Date: Tue, 28 May 2013 06:59:27 -0400
Subject: Problems with python and pyQT
In-Reply-To: <646e6bae-b0fc-46fe-bf60-23ec9b4958a3@googlegroups.com>
References: <8d8fd7fc-2509-457e-a4c9-0a1ac1f65c02@googlegroups.com>
	<mailman.2249.1369660253.3114.python-list@python.org>
	<646e6bae-b0fc-46fe-bf60-23ec9b4958a3@googlegroups.com>
Message-ID: <51A48E0F.4070803@davea.name>

On 05/28/2013 05:41 AM, silusilusilu at gmail.com wrote:
> Thanks for your reply: very useful!!
> I have another question: with hex command i display (for example)
>
> 0x1
>
> is it possible to display 0x01?

hex() is a function, not a command.  And it only takes the one 
parameter, the int to be converted.

For more generality, try the str.format() method.  The x type converts 
to hex without any prefix, and then you can add the width and fill field.

http://docs.python.org/2/library/stdtypes.html#str.format
http://docs.python.org/2/library/string.html#formatstrings
http://docs.python.org/2/library/string.html#format-specification-mini-language

For starters, try:

print "0x{0:0>2x}".format(12)
or
print "0x{0:0>2X}".format(12)
     if you like uppercase hex characters

-- 
DaveA


From avnesh.nitk at gmail.com  Mon May 27 05:27:59 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Mon, 27 May 2013 02:27:59 -0700 (PDT)
Subject: How to create new python file with increament number,
	if doesn't exist?
Message-ID: <3c99daa0-6f30-4cbf-b107-56021a324f7c@googlegroups.com>

hi,
   I want to create a new python file like 'data0.0.5', but if it is already exist then it should create 'data0.0.6', if it's also exist then next like 'data0.0.7'. I have done, but with range, please give me suggestion so that I can do it with specifying range.
I was trying this way and it's working also..

     i = 0
    for i in range(100):
        try:
            with open('Data%d.%d.%d.json'%(0,0,i,)): pass
            continue
        except IOError:
            edxCorrectDataFile = file('Data%d.%d.%d.json'%(0,0,i,), 'a+')
            break

But here I have defined range 100, Is it possible without range it create many required files?

Thanks


From denismfmcmahon at gmail.com  Mon May 27 06:49:00 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Mon, 27 May 2013 10:49:00 +0000 (UTC)
Subject: How to create new python file with increament number, if
	doesn't exist?
References: <3c99daa0-6f30-4cbf-b107-56021a324f7c@googlegroups.com>
Message-ID: <knvdms$gvn$3@dont-email.me>

On Mon, 27 May 2013 02:27:59 -0700, Avnesh Shakya wrote:

> I want to create a new python file like 'data0.0.5', but if it is
> already exist then it should create 'data0.0.6', if it's also exist
> then next like 'data0.0.7'. I have done, but with range, please give
> me suggestion so that I can do it with specifying range.

Try and put your description into the sequence of instructions you want 
the computer follow.

For this problem, my sequence of instructions would be:

1) Find the highest numbered existing file that matches the filename 
data0.0.[number]

2) Create a new file that is one number higher.

Now the solution is easy. Find the list of filenames in the directory 
that match a suitable regular expression, take the numeric value of a 
substring of the filename for each file and find the highest, add one to 
it, then create the new file name.

Something like the following (untested) with the relevant imports etc:

nfn="data0.0."+str(max([int(f[8:])for f in os.listdir(p)if re.match
('^data0.0.[0-9]+$',f)])+1)

-- 
Denis McMahon, denismfmcmahon at gmail.com


From avnesh.nitk at gmail.com  Mon May 27 07:00:26 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Mon, 27 May 2013 16:30:26 +0530
Subject: How to create new python file with increament number,
	if doesn't exist?
In-Reply-To: <knvdms$gvn$3@dont-email.me>
References: <3c99daa0-6f30-4cbf-b107-56021a324f7c@googlegroups.com>
	<knvdms$gvn$3@dont-email.me>
Message-ID: <CAEA17E+7CU56=6CJBU=YqNtDBbgeV32rPH9-4fz_CEtMNhhb3g@mail.gmail.com>

Thanks


On Mon, May 27, 2013 at 4:19 PM, Denis McMahon <denismfmcmahon at gmail.com>wrote:

> On Mon, 27 May 2013 02:27:59 -0700, Avnesh Shakya wrote:
>
> > I want to create a new python file like 'data0.0.5', but if it is
> > already exist then it should create 'data0.0.6', if it's also exist
> > then next like 'data0.0.7'. I have done, but with range, please give
> > me suggestion so that I can do it with specifying range.
>
> Try and put your description into the sequence of instructions you want
> the computer follow.
>
> For this problem, my sequence of instructions would be:
>
> 1) Find the highest numbered existing file that matches the filename
> data0.0.[number]
>
> 2) Create a new file that is one number higher.
>
> Now the solution is easy. Find the list of filenames in the directory
> that match a suitable regular expression, take the numeric value of a
> substring of the filename for each file and find the highest, add one to
> it, then create the new file name.
>
> Something like the following (untested) with the relevant imports etc:
>
> nfn="data0.0."+str(max([int(f[8:])for f in os.listdir(p)if re.match
> ('^data0.0.[0-9]+$',f)])+1)
>
> --
> Denis McMahon, denismfmcmahon at gmail.com
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From jt at toerring.de  Mon May 27 07:13:19 2013
From: jt at toerring.de (Jens Thoms Toerring)
Date: 27 May 2013 11:13:19 GMT
Subject: How to create new python file with increament number,
	if doesn't exist?
References: <3c99daa0-6f30-4cbf-b107-56021a324f7c@googlegroups.com>
Message-ID: <b0gtefF8i5vU1@mid.uni-berlin.de>

Avnesh Shakya <avnesh.nitk at gmail.com> wrote:
>    I want to create a new python file like 'data0.0.5', but if it is already
> exist then it should create 'data0.0.6', if it's also exist then next like
> 'data0.0.7'. I have done, but with range, please give me suggestion so that
> I can do it with specifying range.
> I was trying this way and it's working also..

>     i = 0
>     for i in range(100):
>         try:
>             with open('Data%d.%d.%d.json'%(0,0,i,)): pass
>             continue
>         except IOError:
>             edxCorrectDataFile = file('Data%d.%d.%d.json'%(0,0,i,), 'a+')
>             break

> But here I have defined range 100, Is it possible without range it create
> many required files?

What about something as simple as this?

  i = 0
  while os.path.exists( 'Data{0}.{1}.{2}.json'.format( 0, 0, i ) ) :
      i += 1
  f = open( 'Data{0}.{1}.{2}.json'.format( 0, 0, i ), 'w' )

For your code you'ld make it e.g.

  i = 0
  try:
      while True :
          with open('Data%d.%d.%d.json'%(0,0,i)):
              i += 1
  except IOError:
      edxCorrectDataFile = file('Data%d.%d.%d.json'%(0,0,i), 'a+')

Note that I don't see how all this trying to open a file and
catching an exeception if it doesn't exist is any better
than simply using os.path.exists(). You may have read some-
where that it avoids a race condition and would thus be more
secure. That's not the case here, an attacker still could
create e.g. a symbolic link with the name of the file you're
going to open between the time the exception is thrown and your
program getting around to open the file you expect not to exist,
so nothing is gained by using this somewhat convoluted method.
What would be needed for avoiding a race condition is an addi-
tional flag to be passed to open() like the for example the
O_EXCL flag that can be passed to Unix' open() system function.
But that isn't supported by Pythons open() function which
rather likeky is based on C's fopen() function). The best
advice to avoid such problems is probably not to open files
with a predictable name (or better to use one of the methods
to create files with names guaranteed to be unique by the
system) in directories to which other users than you also
have write permission.
                            Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de


From livewebcamsexs at gmail.com  Mon May 27 07:43:59 2013
From: livewebcamsexs at gmail.com (MoneyMaker)
Date: Mon, 27 May 2013 04:43:59 -0700 (PDT)
Subject: Scary Pranks
Message-ID: <d4ab32bc-3df8-4efb-8225-28bbbab87a9f@googlegroups.com>

http://horrorhorrorhorror.webs.com/scary-pranks


From mok-kong.shen at t-online.de  Mon May 27 10:45:05 2013
From: mok-kong.shen at t-online.de (Mok-Kong Shen)
Date: Mon, 27 May 2013 16:45:05 +0200
Subject: How to get an integer from a sequence of bytes
Message-ID: <knvrhf$n5n$1@news.albasani.net>

 From an int one can use to_bytes to get its individual bytes,
but how can one reconstruct the int from the sequence of bytes?

Thanks in advance.

M. K. Shen


From steve+comp.lang.python at pearwood.info  Mon May 27 11:00:39 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 27 May 2013 15:00:39 GMT
Subject: How to get an integer from a sequence of bytes
References: <knvrhf$n5n$1@news.albasani.net>
Message-ID: <51a37516$0$30002$c3e8da3$5496439d@news.astraweb.com>

On Mon, 27 May 2013 16:45:05 +0200, Mok-Kong Shen wrote:

> From an int one can use to_bytes to get its individual bytes, but how
> can one reconstruct the int from the sequence of bytes?

Here's one way:

py> n = 11999102937234
py> m = 0
py> for b in n.to_bytes(6, 'big'):
...     m = 256*m + b
...
py> m == n
True


-- 
Steven



From carlosnepomuceno at outlook.com  Mon May 27 20:37:37 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 03:37:37 +0300
Subject: How to get an integer from a sequence of bytes
In-Reply-To: <51a37516$0$30002$c3e8da3$5496439d@news.astraweb.com>
References: <knvrhf$n5n$1@news.albasani.net>,
	<51a37516$0$30002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <BLU176-W8970A68A3C0DD6F76F325D7970@phx.gbl>

----------------------------------------
> From: steve+comp.lang.python at pearwood.info
> Subject: Re: How to get an integer from a sequence of bytes
> Date: Mon, 27 May 2013 15:00:39 +0000
> To: python-list at python.org
>
> On Mon, 27 May 2013 16:45:05 +0200, Mok-Kong Shen wrote:
>
>> From an int one can use to_bytes to get its individual bytes, but how
>> can one reconstruct the int from the sequence of bytes?
>
> Here's one way:
>
> py> n = 11999102937234
> py> m = 0
> py> for b in n.to_bytes(6, 'big'):
> ... m = 256*m + b
> ...
> py> m == n
> True
>
>
> --
> Steven
>
> --
> http://mail.python.org/mailman/listinfo/python-list

Python 2 doesn't have to_bytes()! :(

# Python 2, LSB 1st
def to_lil_bytes(x):
??? r = []
??? while x != 0:
??????? r.append(int(x & 0b11111111))
??????? x>>= 8
??? return r

# Python 2, LSB 1st
def from_lil_bytes(l):
??? x = 0
??? for i in range(len(l)-1, -1, -1):
??????? x <<= 8
??????? x |= l[i]
??? return x

# Python 2, MSB 1st
def to_big_bytes(x):
??? r = []
??? while x != 0:
??????? r.insert(0, int(x & 0b11111111))
??????? x>>= 8
??? return r

# Python 2, MSB 1st
def from_big_bytes(l):
??? x = 0
??? for i in range(len(l)):
??????? x <<= 8
??????? x |= l[i]
??? return x

Can it be faster? 		 	   		  

From ned at nedbatchelder.com  Mon May 27 11:30:18 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Mon, 27 May 2013 11:30:18 -0400
Subject: How to get an integer from a sequence of bytes
In-Reply-To: <knvrhf$n5n$1@news.albasani.net>
References: <knvrhf$n5n$1@news.albasani.net>
Message-ID: <51A37C0A.1030608@nedbatchelder.com>

On 5/27/2013 10:45 AM, Mok-Kong Shen wrote:
> From an int one can use to_bytes to get its individual bytes,
> but how can one reconstruct the int from the sequence of bytes?
>

The next thing in the docs after int.to_bytes is int.from_bytes: 
http://docs.python.org/3.3/library/stdtypes.html#int.from_bytes

--Ned.

> Thanks in advance.
>
> M. K. Shen



From steve+comp.lang.python at pearwood.info  Mon May 27 20:31:07 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 28 May 2013 00:31:07 GMT
Subject: How to get an integer from a sequence of bytes
References: <knvrhf$n5n$1@news.albasani.net>
	<mailman.2253.1369668622.3114.python-list@python.org>
Message-ID: <51a3faca$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Mon, 27 May 2013 11:30:18 -0400, Ned Batchelder wrote:

> On 5/27/2013 10:45 AM, Mok-Kong Shen wrote:
>> From an int one can use to_bytes to get its individual bytes, but how
>> can one reconstruct the int from the sequence of bytes?
>>
>>
> The next thing in the docs after int.to_bytes is int.from_bytes:

And I can't believe I missed that too :-(


-- 
Steven


From davea at davea.name  Mon May 27 20:41:59 2013
From: davea at davea.name (Dave Angel)
Date: Mon, 27 May 2013 20:41:59 -0400
Subject: How to get an integer from a sequence of bytes
In-Reply-To: <51a3faca$0$29966$c3e8da3$5496439d@news.astraweb.com>
References: <knvrhf$n5n$1@news.albasani.net>
	<mailman.2253.1369668622.3114.python-list@python.org>
	<51a3faca$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <51A3FD57.1030905@davea.name>

On 05/27/2013 08:31 PM, Steven D'Aprano wrote:
> On Mon, 27 May 2013 11:30:18 -0400, Ned Batchelder wrote:
>
>> On 5/27/2013 10:45 AM, Mok-Kong Shen wrote:
>>>  From an int one can use to_bytes to get its individual bytes, but how
>>> can one reconstruct the int from the sequence of bytes?
>>>
>>>
>> The next thing in the docs after int.to_bytes is int.from_bytes:
>
> And I can't believe I missed that too :-(
>
>
And that approach probably works for negative ints too.


-- 
DaveA


From mok-kong.shen at t-online.de  Thu May 30 14:26:10 2013
From: mok-kong.shen at t-online.de (Mok-Kong Shen)
Date: Thu, 30 May 2013 20:26:10 +0200
Subject: How to get an integer from a sequence of bytes
In-Reply-To: <mailman.2253.1369668622.3114.python-list@python.org>
References: <knvrhf$n5n$1@news.albasani.net>
	<mailman.2253.1369668622.3114.python-list@python.org>
Message-ID: <ko85jp$vn3$1@news.albasani.net>

Am 27.05.2013 17:30, schrieb Ned Batchelder:
> On 5/27/2013 10:45 AM, Mok-Kong Shen wrote:
>> From an int one can use to_bytes to get its individual bytes,
>> but how can one reconstruct the int from the sequence of bytes?
>>
> The next thing in the docs after int.to_bytes is int.from_bytes:
> http://docs.python.org/3.3/library/stdtypes.html#int.from_bytes

I am sorry to have overlooked that. But one thing I yet wonder is why
there is no direct possibilty of converting a byte to an int in [0,255],
i.e. with a constrct int(b), where b is a byte.

M. K. Shen



From ian.g.kelly at gmail.com  Thu May 30 14:42:24 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 30 May 2013 12:42:24 -0600
Subject: How to get an integer from a sequence of bytes
In-Reply-To: <ko85jp$vn3$1@news.albasani.net>
References: <knvrhf$n5n$1@news.albasani.net>
	<mailman.2253.1369668622.3114.python-list@python.org>
	<ko85jp$vn3$1@news.albasani.net>
Message-ID: <CALwzidmY8ZH2Bp4L9uikdM_hOM0PfWDFVt7rZ+Rn_Ehiz6QUOA@mail.gmail.com>

On Thu, May 30, 2013 at 12:26 PM, Mok-Kong Shen
<mok-kong.shen at t-online.de> wrote:
> Am 27.05.2013 17:30, schrieb Ned Batchelder:
>>
>> On 5/27/2013 10:45 AM, Mok-Kong Shen wrote:
>>>
>>> From an int one can use to_bytes to get its individual bytes,
>>> but how can one reconstruct the int from the sequence of bytes?
>>>
>> The next thing in the docs after int.to_bytes is int.from_bytes:
>> http://docs.python.org/3.3/library/stdtypes.html#int.from_bytes
>
>
> I am sorry to have overlooked that. But one thing I yet wonder is why
> there is no direct possibilty of converting a byte to an int in [0,255],
> i.e. with a constrct int(b), where b is a byte.

The bytes object can be viewed as a sequence of ints.  So if b is a
bytes object of non-zero length, then b[0] is an int in range(0, 256).


From wxjmfauth at gmail.com  Thu May 30 14:53:15 2013
From: wxjmfauth at gmail.com (jmfauth)
Date: Thu, 30 May 2013 11:53:15 -0700 (PDT)
Subject: How to get an integer from a sequence of bytes
References: <knvrhf$n5n$1@news.albasani.net>
	<mailman.2253.1369668622.3114.python-list@python.org>
	<ko85jp$vn3$1@news.albasani.net>
	<mailman.2444.1369939393.3114.python-list@python.org>
Message-ID: <e5ef97fb-1449-4e92-af16-08305648fc2d@l5g2000vbn.googlegroups.com>

On 30 mai, 20:42, Ian Kelly <ian.g.ke... at gmail.com> wrote:
> On Thu, May 30, 2013 at 12:26 PM, Mok-Kong Shen
>
> <mok-kong.s... at t-online.de> wrote:
> > Am 27.05.2013 17:30, schrieb Ned Batchelder:
>
> >> On 5/27/2013 10:45 AM, Mok-Kong Shen wrote:
>
> >>> From an int one can use to_bytes to get its individual bytes,
> >>> but how can one reconstruct the int from the sequence of bytes?
>
> >> The next thing in the docs after int.to_bytes is int.from_bytes:
> >>http://docs.python.org/3.3/library/stdtypes.html#int.from_bytes
>
> > I am sorry to have overlooked that. But one thing I yet wonder is why
> > there is no direct possibilty of converting a byte to an int in [0,255],
> > i.e. with a constrct int(b), where b is a byte.
>
> The bytes object can be viewed as a sequence of ints. ?So if b is a
> bytes object of non-zero length, then b[0] is an int in range(0, 256).

----

Well, Python now "speaks" only "integer", the rest is
commodity and there is a good coherency.

>>> bin(255)
'0b11111111'
>>> oct(255)
'0o377'
>>> 255
255
>>> hex(255)
'0xff'
>>>
>>> int('0b11111111', 2)
255
>>> int('0o377', 8)
255
>>> int('255')
255
>>> int('0xff', 16)
255
>>>
>>> 0b11111111
255
>>> 0o377
255
>>> 255
255
>>> 0xff
255
>>>
>>> type(0b11111111)
<class 'int'>
>>> type(0o377)
<class 'int'>
>>> type(255)
<class 'int'>
>>> type(0xff)
<class 'int'>

jmf


From ned at nedbatchelder.com  Thu May 30 15:22:26 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Thu, 30 May 2013 15:22:26 -0400
Subject: How to get an integer from a sequence of bytes
In-Reply-To: <ko85jp$vn3$1@news.albasani.net>
References: <knvrhf$n5n$1@news.albasani.net>
	<mailman.2253.1369668622.3114.python-list@python.org>
	<ko85jp$vn3$1@news.albasani.net>
Message-ID: <51A7A6F2.3070007@nedbatchelder.com>


On 5/30/2013 2:26 PM, Mok-Kong Shen wrote:
> Am 27.05.2013 17:30, schrieb Ned Batchelder:
>> On 5/27/2013 10:45 AM, Mok-Kong Shen wrote:
>>> From an int one can use to_bytes to get its individual bytes,
>>> but how can one reconstruct the int from the sequence of bytes?
>>>
>> The next thing in the docs after int.to_bytes is int.from_bytes:
>> http://docs.python.org/3.3/library/stdtypes.html#int.from_bytes
>
> I am sorry to have overlooked that. But one thing I yet wonder is why
> there is no direct possibilty of converting a byte to an int in [0,255],
> i.e. with a constrct int(b), where b is a byte.
>

Presumably you want this to work:

     >>> int(b'\x03')
     3

But you also want this to work:

     >>> int(b'7')
     7

These two interpretations are incompatible.  If b'\x03' becomes 3, then 
shouldn't b'\x37' become 55?  But b'\x37' is b'7', and you want that to 
be 7.

--Ned.

> M. K. Shen
>



From invalid at invalid.invalid  Tue May 28 12:04:01 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 16:04:01 +0000 (UTC)
Subject: How to get an integer from a sequence of bytes
References: <knvrhf$n5n$1@news.albasani.net>
Message-ID: <ko2khh$9oh$5@reader1.panix.com>

On 2013-05-27, Mok-Kong Shen <mok-kong.shen at t-online.de> wrote:
>  From an int one can use to_bytes to get its individual bytes,
> but how can one reconstruct the int from the sequence of bytes?

One way is using the struct module.

-- 
Grant Edwards               grant.b.edwards        Yow! Uh-oh!!  I forgot
                                  at               to submit to COMPULSORY
                              gmail.com            URINALYSIS!


From phd at phdru.name  Sun May 26 13:37:03 2013
From: phd at phdru.name (Oleg Broytman)
Date: Sun, 26 May 2013 21:37:03 +0400
Subject: SQLObject 1.3.3 and 1.4.1
Message-ID: <20130526173703.GC14598@iskra.aviel.ru>

Hello!

I'm pleased to announce bugfix releases 1.3.3 and 1.4.1.


What's new in SQLObject
=======================

* Fixed bugs in pickling and unpickling (remove/restore a weak proxy to self,
  fixed cache handling).

* Added an example of using SQLObject with web.py to the links page.

Contributors for this release are Andrew Trusty and Rhubarb Sin.

For a more complete list, please see the news:
http://sqlobject.org/News.html


What is SQLObject
=================

SQLObject is an object-relational mapper.  Your database tables are described
as classes, and rows are instances of those classes.  SQLObject is meant to be
easy to use and quick to get started with.

SQLObject supports a number of backends: MySQL, PostgreSQL, SQLite,
Firebird, Sybase, MSSQL and MaxDB (also known as SAPDB).


Where is SQLObject
==================

Site:
http://sqlobject.org

Development:
http://sqlobject.org/devel/

Mailing list:
https://lists.sourceforge.net/mailman/listinfo/sqlobject-discuss

Archives:
http://news.gmane.org/gmane.comp.python.sqlobject

Download:
https://pypi.python.org/pypi/SQLObject/1.3.3
https://pypi.python.org/pypi/SQLObject/1.4.1

News and changes:
http://sqlobject.org/News.html

Oleg.
-- 
     Oleg Broytman            http://phdru.name/            phd at phdru.name
           Programmers don't die, they just GOSUB without RETURN.


From britten.bryan at gmail.com  Mon May 27 16:47:40 2013
From: britten.bryan at gmail.com (Bryan Britten)
Date: Mon, 27 May 2013 13:47:40 -0700 (PDT)
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
Message-ID: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>

Hey, everyone! 

I'm very new to Python and have only been using it for a couple of days, but have some experience in programming (albeit mostly statistical programming in SAS or R) so I'm hoping someone can answer this question in a technical way, but without using an abundant amount of jargon.

The issue I'm having is that I'm trying to pull information from a website to practice Python with, but I'm having trouble getting the data in a timely fashion. If I use the following code:

<code>
import json
import urllib

urlStr = "https://stream.twitter.com/1/statuses/sample.json"

twtrDict = [json.loads(line) for line in urllib.urlopen(urlStr)]
</code>

I get a memory issue. I'm running 32-bit Python 2.7 with 4 gigs of RAM if that helps at all.

If I use the following code:

<code>
import urllib

urlStr = "https://stream.twitter.com/1/statuses/sample.json"

fileHandle = urllib.urlopen(urlStr)

twtrText = fileHandle.readlines()
</code>

It takes hours (upwards of 6 or 7, if not more) to finish computing the last command.

With that being said, my question is whether there is a more efficient manner to do this. I'm worried that if it's taking this long to process the .readlines() command, trying to work with the data is going to be a computational nightmare.

Thanks in advance for any insights or advice!


From roy at panix.com  Mon May 27 16:56:31 2013
From: roy at panix.com (Roy Smith)
Date: Mon, 27 May 2013 16:56:31 -0400
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
References: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
Message-ID: <roy-E04E0C.16563127052013@news.panix.com>

In article <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e at googlegroups.com>,
 Bryan Britten <britten.bryan at gmail.com> wrote:

> If I use the following code:
> 
> <code>
> import urllib
> 
> urlStr = "https://stream.twitter.com/1/statuses/sample.json"
> 
> fileHandle = urllib.urlopen(urlStr)
> 
> twtrText = fileHandle.readlines()
> </code>
> 
> It takes hours (upwards of 6 or 7, if not more) to finish computing the last 
> command.

I'm not surprised!  readlines() reads in the ENTIRE file in one gulp.  
That a lot of tweets!

> With that being said, my question is whether there is a more efficient manner 
> to do this.

In general, when reading a large file, you want to iterate over lines of 
the file and process each one.  Something like:

for line in urllib.urlopen(urlStr):
   twtrDict = json.loads(line)

You still need to download and process all the data, but at least you 
don't need to store it in memory all at once.  There is an assumption 
here that there's exactly one json object per line.  If that's not the 
case, things might get a little more complicated.


From britten.bryan at gmail.com  Mon May 27 17:29:38 2013
From: britten.bryan at gmail.com (Bryan Britten)
Date: Mon, 27 May 2013 14:29:38 -0700 (PDT)
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
In-Reply-To: <roy-E04E0C.16563127052013@news.panix.com>
References: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
	<roy-E04E0C.16563127052013@news.panix.com>
Message-ID: <a35f5ef7-d458-4ae6-a64a-2690a335b0f4@googlegroups.com>

Try to not sigh audibly as I ask what I'm sure are two asinine questions. 

1) How is this approach different from twtrDict = [json.loads(line) for line in urllib.urlopen(urlStr)]?

2) How do I tell how many JSON objects are on each line?





From denismfmcmahon at gmail.com  Mon May 27 17:35:22 2013
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Mon, 27 May 2013 21:35:22 +0000 (UTC)
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
References: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
	<roy-E04E0C.16563127052013@news.panix.com>
	<a35f5ef7-d458-4ae6-a64a-2690a335b0f4@googlegroups.com>
Message-ID: <ko0jiq$a5h$3@dont-email.me>

On Mon, 27 May 2013 14:29:38 -0700, Bryan Britten wrote:

> Try to not sigh audibly as I ask what I'm sure are two asinine
> questions.
> 
> 1) How is this approach different from twtrDict = [json.loads(line) for
> line in urllib.urlopen(urlStr)]?
> 
> 2) How do I tell how many JSON objects are on each line?

Your code at (1) creates a single list of all the json objects

The code you replied to loaded each object, assumed you did something 
with it, and then over-wrote it with the next one.

As for (2) - either inspection, or errors from the json parser.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From fabiosantosart at gmail.com  Mon May 27 19:36:54 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 28 May 2013 00:36:54 +0100
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
In-Reply-To: <a35f5ef7-d458-4ae6-a64a-2690a335b0f4@googlegroups.com>
References: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
	<roy-E04E0C.16563127052013@news.panix.com>
	<a35f5ef7-d458-4ae6-a64a-2690a335b0f4@googlegroups.com>
Message-ID: <CAA=1kxR+cMi_TNRe1ZfgPzVQhN71bqAydiNkuP0+_4BRxwc0yw@mail.gmail.com>

On 27 May 2013 22:36, "Bryan Britten" <britten.bryan at gmail.com> wrote:
>
> Try to not sigh audibly as I ask what I'm sure are two asinine questions.
>
> 1) How is this approach different from twtrDict = [json.loads(line) for
line in urllib.urlopen(urlStr)]?
>

The suggested approach made use of generators. Just because you can iterate
over something, that doesn't mean it is all in memory ;)

Check out the difference between range() and xrange() in python 2
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From davea at davea.name  Mon May 27 19:58:05 2013
From: davea at davea.name (Dave Angel)
Date: Mon, 27 May 2013 19:58:05 -0400
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
In-Reply-To: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
References: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
Message-ID: <51A3F30D.5070800@davea.name>

On 05/27/2013 04:47 PM, Bryan Britten wrote:
> Hey, everyone!
>
> I'm very new to Python and have only been using it for a couple of days, but have some experience in programming (albeit mostly statistical programming in SAS or R) so I'm hoping someone can answer this question in a technical way, but without using an abundant amount of jargon.
>
> The issue I'm having is that I'm trying to pull information from a website to practice Python with, but I'm having trouble getting the data in a timely fashion. If I use the following code:
>
> <code>
> import json
> import urllib
>
> urlStr = "https://stream.twitter.com/1/statuses/sample.json"
>
> twtrDict = [json.loads(line) for line in urllib.urlopen(urlStr)]
> </code>
>
> I get a memory issue. I'm running 32-bit Python 2.7 with 4 gigs of RAM if that helps at all.

Which OS?

The first question I'd ask is how big this file is.  I can't tell, since 
it needs a user name & password to actually get the file.  But it's not 
unusual to need at least double that space in memory, and in Windoze 
you're limited to two gig max, regardless of how big your hardware might be.

If you separately fetch the file, then you can experiment with it, 
including cutting it down to a dozen lines, and see if you can deal with 
that much.

How could you fetch it?  With wget, with a browser (and saveAs), with a 
simple loop which uses read(4096) repeatedly and writes each block to a 
local file.  Don't forget to use 'wb', as you don't know yet what line 
endings it might use.

Once you have an idea what the data looks like, you can answer such 
questions as whether it's json at all, whether the lines each contain a 
single json record, or what.

For all we know, the file might be a few terabytes in size.


-- 
DaveA


From britten.bryan at gmail.com  Mon May 27 23:11:34 2013
From: britten.bryan at gmail.com (Bryan Britten)
Date: Mon, 27 May 2013 20:11:34 -0700 (PDT)
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
In-Reply-To: <mailman.2268.1369699108.3114.python-list@python.org>
References: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
	<mailman.2268.1369699108.3114.python-list@python.org>
Message-ID: <4db5a3be-d9dc-455c-8e3b-5adebad2dcdd@googlegroups.com>

On Monday, May 27, 2013 7:58:05 PM UTC-4, Dave Angel wrote:
> On 05/27/2013 04:47 PM, Bryan Britten wrote:
> 
> > Hey, everyone!
> 
> >
> 
> > I'm very new to Python and have only been using it for a couple of days, but have some experience in programming (albeit mostly statistical programming in SAS or R) so I'm hoping someone can answer this question in a technical way, but without using an abundant amount of jargon.
> 
> >
> 
> > The issue I'm having is that I'm trying to pull information from a website to practice Python with, but I'm having trouble getting the data in a timely fashion. If I use the following code:
> 
> >
> 
> > <code>
> 
> > import json
> 
> > import urllib
> 
> >
> 
> > urlStr = "https://stream.twitter.com/1/statuses/sample.json"
> 
> >
> 
> > twtrDict = [json.loads(line) for line in urllib.urlopen(urlStr)]
> 
> > </code>
> 
> >
> 
> > I get a memory issue. I'm running 32-bit Python 2.7 with 4 gigs of RAM if that helps at all.
> 
> 
> 
> Which OS?

I'm operating on Windows 7.

> 
> The first question I'd ask is how big this file is.  I can't tell, since 
> 
> it needs a user name & password to actually get the file.  

If you have Twitter, you can just use your log-in information to access the file.

> But it's not unusual to need at least double that space in memory, and in Windoze 
> 
> you're limited to two gig max, regardless of how big your hardware might be.
> 
> 
> 
> If you separately fetch the file, then you can experiment with it, 
> 
> including cutting it down to a dozen lines, and see if you can deal with 
> 
> that much.
> 
> 
> 
> How could you fetch it?  With wget, with a browser (and saveAs), with a 
> 
> simple loop which uses read(4096) repeatedly and writes each block to a 
> 
> local file.  Don't forget to use 'wb', as you don't know yet what line 
> 
> endings it might use.
> 
I'm not familiar with using read(4096), I'll have to look into that. When I tried to just save the file, my computer just sat in limbo for some time and didn't seem to want to process the command. 
> 
> Once you have an idea what the data looks like, you can answer such 
> 
> questions as whether it's json at all, whether the lines each contain a 
> 
> single json record, or what.
> 
Based on my *extremely* limited knowledge of JSON, that's definitely the type of file this is. Here is a snippet of what is seen when you log in:

{"created_at":"Tue May 28 03:09:23 +0000 2013","id":339216806461972481,"id_str":"339216806461972481","text":"RT @aleon_11: Sigo creyendo que las noches lluviosas me acercan mucho m\u00e1s a ti!","source":"\u003ca href=\"http:\/\/blackberry.com\/twitter\" rel=\"nofollow\"\u003eTwitter for BlackBerry\u00ae\u003c\/a\u003e","truncated":false,"in_reply_to_status_id":null,"in_reply_to_status_id_str":null,"in_reply_to_user_id":null,"in_reply_to_user_id_str":null,"in_reply_to_screen_name":null,"user":{"id":310910123,"id_str":"310910123","name":"\u2661","screen_name":"LaMarielita_","location":"","url":null,"description":"MERCADOLOGA & PUBLICISTA EN PROCESO, AMO A MI DIOS & MI FAMILIA\u2665 ME ENCANTA REIRME , MOLESTAR & HABLAR :D BFF, pancho, ale & china :) LY\u2661","protected":false,"followers_count":506,"friends_count":606,"listed_count":1,"created_at":"Sat Jun 04 15:24:19 +0000 2011","favourites_count":207,"utc_offset":-25200,"time_zone":"Mountain Time (US & Canada)","geo_enabled":false,"verified":false,"statuses_count":17241,"lang":"es","contributors_enabled":false,"is_translator":false,"profile_background_color":"FF6699","profile_background_image_url":"http:\/\/a0.twimg.com\/images\/themes\/theme11\/bg.gif","profile_background_image_url_https":"https:\/\/si0.twimg.com\/images\/themes\/theme11\/bg.gif","profile_background_tile":true,"profile_image_url":"http:\/\/a0.twimg.com\/profile_images\/3720425493\/13a48910e56ca34edeea07ff04075c77_normal.jpeg","profile_image_url_https":"https:\/\/si0.twimg.com\/profile_images\/3720425493\/13a48910e56ca34edeea07ff04075c77_normal.jpeg","profile_link_color":"B40B43","profile_sidebar_border_color":"CC3366","profile_sidebar_fill_color":"E5507E","profile_text_color":"362720","profile_use_background_image":true,"default_profile":false,"default_profile_image":false,"following":null,"follow_request_sent":null,"notifications":null},"geo":null,"coordinates":null,"place":null,"contributors":null,"retweeted_status":{"created_at":"Tue May 28 02:57:40 +0000 2013","id":339213856922537984,"id_str":"339213856922537984","text":"Sigo creyendo que las noches lluviosas me acercan mucho m\u00e1s a ti!","source":"web","truncated":false,"in_reply_to_status_id":null,"in_reply_to_status_id_str":null,"in_reply_to_user_id":null,"in_reply_to_user_id_str":null,"in_reply_to_screen_name":null,"user":{"id":105252134,"id_str":"105252134","name":"Alejandra Le\u00f3n","screen_name":"aleon_11","location":"Guatemala","url":null,"description":"La vida se disfruta m\u00e1s, cuando no se le pone tanta importancia.","protected":false,"followers_count":143,"friends_count":251,"listed_count":0,"created_at":"Fri Jan 15 20:49:38 +0000 2010","favourites_count":83,"utc_offset":-28800,"time_zone":"Pacific Time (US & Canada)","geo_enabled":false,"verified":false,"statuses_count":1863,"lang":"es","contributors_enabled":false,"is_translator":false,"profile_background_color":"F8F2FC","profile_background_image_url":"http:\/\/a0.twimg.com\/profile_background_images\/811443451\/81abf2f37ee3e37deda396befa7fb557.jpeg","profile_background_image_url_https":"https:\/\/si0.twimg.com\/profile_background_images\/811443451\/81abf2f37ee3e37deda396befa7fb557.jpeg","profile_background_tile":true,"profile_image_url":"http:\/\/a0.twimg.com\/profile_images\/3578979563\/e973196904e25af5d960f2971616eb61_normal.jpeg","profile_image_url_https":"https:\/\/si0.twimg.com\/profile_images\/3578979563\/e973196904e25af5d960f2971616eb61_normal.jpeg","profile_banner_url":"https:\/\/pbs.twimg.com\/profile_banners\/105252134\/1364957374","profile_link_color":"F01A1A","profile_sidebar_border_color":"000000","profile_sidebar_fill_color":"7AC3EE","profile_text_color":"3D1957","profile_use_background_image":true,"default_profile":false,"default_profile_image":false,"following":null,"follow_request_sent":null,"notifications":null},"geo":null,"coordinates":null,"place":null,"contributors":null,"retweet_count":2,"favorite_count":0,"entities":{"hashtags":[],"symbols":[],"urls":[],"user_mentions":[]},"favorited":false,"retweeted":false,"lang":"es"},"retweet_count":0,"favorite_count":0,"entities":{"hashtags":[],"symbols":[],"urls":[],"user_mentions":[{"screen_name":"aleon_11","name":"Alejandra Le\u00f3n","id":105252134,"id_str":"105252134","indices":[3,12]}]},"favorited":false,"retweeted":false,"filter_level":"low"}

> 
> For all we know, the file might be a few terabytes in size.
> 
> 
> 
> 
> 
> -- 
> 
> DaveA


From fabiosantosart at gmail.com  Tue May 28 03:31:35 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 28 May 2013 08:31:35 +0100
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
In-Reply-To: <4db5a3be-d9dc-455c-8e3b-5adebad2dcdd@googlegroups.com>
References: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
	<mailman.2268.1369699108.3114.python-list@python.org>
	<4db5a3be-d9dc-455c-8e3b-5adebad2dcdd@googlegroups.com>
Message-ID: <CAA=1kxSMK=DYySzddKB-amGfG6_zk=jq0ZvYrL6WP9BKL1kctw@mail.gmail.com>

On 28 May 2013 04:19, "Bryan Britten" <britten.bryan at gmail.com> wrote:
> I'm not familiar with using read(4096), I'll have to look into that. When
I tried to just save the file, my computer just sat in limbo for some time
and didn't seem to want to process the command.

That's just file.read with an integer argument. You can read a file by
chunks by repeatedly calling that function until you get the empty string.

> Based on my *extremely* limited knowledge of JSON, that's definitely the
type of file this is. Here is a snippet of what is seen when you log in:
...
That's json. It's pretty big, but not big enough to stall a slow computer
more than half a second.

-

I've looked for documentation on that method on twitter.

It seems that it's part of the twitter streaming api.

https://dev.twitter.com/docs/streaming-apis

What this means is that the requests aren't supposed to end. They are
supposed to be read gradually, using the lines to split the response into
meaningful chunks. That's why you can't read the data and why your browser
never gets around to download it. Both urlopen and your browser block while
waiting for the request to end.

Here's more info on streaming requests on their docs:

https://dev.twitter.com/docs/streaming-apis/processing

For streaming requests in python, I would point you to the requests
library, but I am not sure it handles streaming requests.
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From britten.bryan at gmail.com  Tue May 28 10:32:20 2013
From: britten.bryan at gmail.com (Bryan Britten)
Date: Tue, 28 May 2013 07:32:20 -0700 (PDT)
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
In-Reply-To: <mailman.2286.1369726304.3114.python-list@python.org>
References: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
	<mailman.2268.1369699108.3114.python-list@python.org>
	<4db5a3be-d9dc-455c-8e3b-5adebad2dcdd@googlegroups.com>
	<mailman.2286.1369726304.3114.python-list@python.org>
Message-ID: <31d86773-88d4-43e2-8699-39021a5f27b8@googlegroups.com>

Thanks to everyone for the help and insight. I think for now I'll just back away from this file and go back to something much easier to practice with. 


From alister.ware at ntlworld.com  Tue May 28 13:52:28 2013
From: alister.ware at ntlworld.com (Alister)
Date: Tue, 28 May 2013 17:52:28 GMT
Subject: Reading *.json from URL - json.loads() versus
	urllib.urlopen.readlines()
References: <10be5c62-4c58-4b4f-b00a-82d85ee4ef8e@googlegroups.com>
	<mailman.2268.1369699108.3114.python-list@python.org>
	<4db5a3be-d9dc-455c-8e3b-5adebad2dcdd@googlegroups.com>
	<mailman.2286.1369726304.3114.python-list@python.org>
Message-ID: <w96pt.47153$0L6.13686@fx20.am4>

On Tue, 28 May 2013 08:31:35 +0100, F?bio Santos wrote:

> On 28 May 2013 04:19, "Bryan Britten" <britten.bryan at gmail.com> wrote:
>> I'm not familiar with using read(4096), I'll have to look into that.
>> When
> I tried to just save the file, my computer just sat in limbo for some
> time and didn't seem to want to process the command.
> 
> That's just file.read with an integer argument. You can read a file by
> chunks by repeatedly calling that function until you get the empty
> string.
> 
>> Based on my *extremely* limited knowledge of JSON, that's definitely
>> the
> type of file this is. Here is a snippet of what is seen when you log in:
> ...
> That's json. It's pretty big, but not big enough to stall a slow
> computer more than half a second.
> 
> -
> 
> I've looked for documentation on that method on twitter.
> 
> It seems that it's part of the twitter streaming api.
> 
> https://dev.twitter.com/docs/streaming-apis
> 
> What this means is that the requests aren't supposed to end. They are
> supposed to be read gradually, using the lines to split the response
> into meaningful chunks. That's why you can't read the data and why your
> browser never gets around to download it. Both urlopen and your browser
> block while waiting for the request to end.

Are we overlooking the obvious
why not use one of the Python twitter modules to isolate your app from 
the nitty-gritty details of the twitter stream 

https://dev.twitter.com/docs/twitter-libraries

-- 
Given sufficient time, what you put off doing today will get done by 
itself.


From romila.anamaria at yahoo.com  Mon May 27 16:50:24 2013
From: romila.anamaria at yahoo.com (Romila Anamaria)
Date: Mon, 27 May 2013 20:50:24 -0000
Subject: .mat files processing in Python
Message-ID: <1369687416.80604.YahooMailNeo@web161705.mail.bf1.yahoo.com>

Hello,


I am beginner
in Python programming and I want to make an application (GUI) in Python 2.6 +
wxPython for process data stored in? .mat
files .
?
(I make such
data? processing in MatLAB.)
?
My application
consists in:
??????????????? -selecting the path of the files
process? and? the file i want to process
?
The .mat files
contain several variables:
??????????????? -each variable corresponds to a
key
?
-when I select one key (or
multiple keys) I want process only values ?? of variable(variables) that i
have?? selected
??
- I want to check if each
value is within the limits specified by me (minimum and maximum? given in interactively mode from the
interface- for example a textbox) and show me status of comparison:? passed (if all values ??are in range) or
failed (if one or more values are ??out of range) + the ?values ??that are out of limits
??
- after comparison, the
results should be saved in a template( excel file) which I want to complete in
the interface with the name of the person who makes the"test", time,
file name, name of the variable / variables, and for variables? specify status:? passed / failed, and for ? failed?? speify the values ??that came out of limits
?
?-I want to do graphics
(plots) of variation of values ??in time, and there should be a different
colored line on both sides of the graph to be one line with different color-the
lines mark the boundaries? of values
- I want to make a
comparison between two measurements of values that belong to the same variable,
within the same graphic
-I want to save these
graphics in. jpeg or . png format, and integrated these graphics in the excel
template?


Can someone help me to make this application?



Thanks!
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From dwight.guth at gmail.com  Mon May 27 17:22:17 2013
From: dwight.guth at gmail.com (dwight.guth at gmail.com)
Date: Mon, 27 May 2013 14:22:17 -0700 (PDT)
Subject: Minor consistency question in io.IOBase
Message-ID: <b2c97ef7-dafe-415c-9793-aeb24f3f691d@googlegroups.com>

Hi, so, I don't necessarily know if this is the right place to ask this question since it's kindof a rather technical one which gets into details of the python interpreter itself, but I thought I'd start here and if nobody knew the answer, they could let me know if it makes sense to ask on python-dev.

I am wondering why it is that the default implementations of certain of the "mixin" methods on IOBase seem to behave somewhat inconsistently. Specifically, the behavior of precisely when in the pipeline a method checks to see whether the object is already closed seems to be inconsistent.

In the following methods:

IOBase.__next__
IOBase.readline
IOBase.tell

In each case, these methods never check to see whether the file is closed. __next__ immediately calls readline(), readline(limit) calls read(1) at most limit times, and tell calls seek(0, 1). It is relying on the underlying method to raise a ValueError if the file is already closed. Otherwise, __next__ and readline will raise AttributeErrors on unreadable files, and tell will raise an UnsupportedOperation on unseekable files. A side effect of this is that readline(0) on a closed file will succeed.

In the following methods, however:

IOBase.writelines
IOBase.readlines

In each case, the methods will check to determine whether the file has been closed before ever calling their underlying method. Thus, calling writelines([]) will raise a ValueError on a closed file, though it never calls write. Similarly, readlines() will raise a ValueError on a closed file before ever calling readline() even once.

Can someone explain to me if there's some kind of consistent logic that explains the differing behaviors of these functions? Or is it simply an oversight on the part of the people who wrote Modules/_io/iobase.c?


From carlosnepomuceno at outlook.com  Mon May 27 21:59:33 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 04:59:33 +0300
Subject: Minor consistency question in io.IOBase
In-Reply-To: <b2c97ef7-dafe-415c-9793-aeb24f3f691d@googlegroups.com>
References: <b2c97ef7-dafe-415c-9793-aeb24f3f691d@googlegroups.com>
Message-ID: <BLU176-W2798D05A76EFBE313F57F9D7970@phx.gbl>

----------------------------------------
> Date: Mon, 27 May 2013 14:22:17 -0700
> Subject: Minor consistency question in io.IOBase
> From: dwight.guth at gmail.com
> To: python-list at python.org
>
> Hi, so, I don't necessarily know if this is the right place to ask this question since it's kindof a rather technical one which gets into details of the python interpreter itself, but I thought I'd start here and if nobody knew the answer, they could let me know if it makes sense to ask on python-dev.
>
> I am wondering why it is that the default implementations of certain of the "mixin" methods on IOBase seem to behave somewhat inconsistently. Specifically, the behavior of precisely when in the pipeline a method checks to see whether the object is already closed seems to be inconsistent.
>
> In the following methods:
>
> IOBase.__next__
> IOBase.readline
> IOBase.tell
>
> In each case, these methods never check to see whether the file is closed. __next__ immediately calls readline(), readline(limit) calls read(1) at most limit times, and tell calls seek(0, 1). It is relying on the underlying method to raise a ValueError if the file is already closed. Otherwise, __next__ and readline will raise AttributeErrors on unreadable files, and tell will raise an UnsupportedOperation on unseekable files. A side effect of this is that readline(0) on a closed file will succeed.

According to [1] & [2] it's a bug! Report the issue: http://bugs.python.org/

"close()
Flush and close this stream. This method has no effect if the file is already closed. Once the file is closed, any operation on the file (e.g. reading or writing) will raise a ValueError."

[1] http://docs.python.org/2/library/io.html#i-o-base-classes
[2] http://docs.python.org/3.3/library/io.html#i-o-base-classes 		 	   		  

From ray at aarden.us  Mon May 27 21:32:43 2013
From: ray at aarden.us (ray)
Date: Mon, 27 May 2013 18:32:43 -0700 (PDT)
Subject: How to:  Setuptools
Message-ID: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>

I would like to use easy_install, but can't figure out how to install it.

I have 64-bit Python 2.7.5 on Windows 7.  

Following the instructions on https://pypi.python.org/pypi/setuptools, it says:
Download ez_setup.py and run it; it will download the appropriate .egg file and install it for you. (Currently, the provided .exe installer does not support 64-bit versions of Python for Windows, due to a distutils installer compatibility issue

Being new to Python, I don't know what it means to "run it".  I am not sure what I am looking at when I open it as the first line is "#!python".

Looking down into the content of ez_setup.py, I find:
'setuptools-0.6c10-py2.6.egg':
but there is no entry
'setuptools-0.6c10-py2.7.egg':

Searching for it, I found a version at:
https://pypi.python.org/packages/2.7/s/setuptools/

This appeared to be a linux version, the first line is:
#!/bin/sh
and the content seems to be encoded.

There is an exe at https://pypi.python.org/pypi/setuptools, but the 
instructions on the page state the .exe won't work for 64-bit installs.

Ray



From carlosnepomuceno at outlook.com  Mon May 27 21:45:03 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 04:45:03 +0300
Subject: How to:  Setuptools
In-Reply-To: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
Message-ID: <BLU176-W177F0C686A5ABF4A48CC81D7970@phx.gbl>

curl -O http://peak.telecommunity.com/dist/ez_setup.py
python ez_setup.py

----------------------------------------
> Date: Mon, 27 May 2013 18:32:43 -0700
> Subject: How to: Setuptools
> From: ray at aarden.us
> To: python-list at python.org
>
> I would like to use easy_install, but can't figure out how to install it.
>
> I have 64-bit Python 2.7.5 on Windows 7.
>
> Following the instructions on https://pypi.python.org/pypi/setuptools, it says:
> Download ez_setup.py and run it; it will download the appropriate .egg file and install it for you. (Currently, the provided .exe installer does not support 64-bit versions of Python for Windows, due to a distutils installer compatibility issue
>
> Being new to Python, I don't know what it means to "run it". I am not sure what I am looking at when I open it as the first line is "#!python".
>
> Looking down into the content of ez_setup.py, I find:
> 'setuptools-0.6c10-py2.6.egg':
> but there is no entry
> 'setuptools-0.6c10-py2.7.egg':
>
> Searching for it, I found a version at:
> https://pypi.python.org/packages/2.7/s/setuptools/
>
> This appeared to be a linux version, the first line is:
> #!/bin/sh
> and the content seems to be encoded.
>
> There is an exe at https://pypi.python.org/pypi/setuptools, but the
> instructions on the page state the .exe won't work for 64-bit installs.
>
> Ray
>
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rustompmody at gmail.com  Mon May 27 22:57:47 2013
From: rustompmody at gmail.com (rusi)
Date: Mon, 27 May 2013 19:57:47 -0700 (PDT)
Subject: How to: Setuptools
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
	<mailman.2275.1369705511.3114.python-list@python.org>
Message-ID: <88d4a817-f991-4599-927f-5b1f9804aa49@ve4g2000pbb.googlegroups.com>

On May 28, 6:45?am, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
wrote:
> curl -Ohttp://peak.telecommunity.com/dist/ez_setup.py
> python ez_setup.py

Curl comes built into windows??
Does not seem so...
http://serverfault.com/questions/483754/is-there-a-built-in-command-line-tool-under-windows-like-wget-curl

Also given that the question clearly says 'I dont know what it means
to "run it" '
I think your two lines could be too cryptic :-)

To the OP: Sorry I am not being very helpful to you -- I am not on
windows now and dont know these commands offhand

I am sure someone else will chime in..


From carlosnepomuceno at outlook.com  Mon May 27 23:06:23 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 06:06:23 +0300
Subject: How to: Setuptools
In-Reply-To: <88d4a817-f991-4599-927f-5b1f9804aa49@ve4g2000pbb.googlegroups.com>
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>,
	<mailman.2275.1369705511.3114.python-list@python.org>,
	<88d4a817-f991-4599-927f-5b1f9804aa49@ve4g2000pbb.googlegroups.com>
Message-ID: <BLU176-W31CFBC1E7B7721BE7B690DD7970@phx.gbl>

----------------------------------------
> Date: Mon, 27 May 2013 19:57:47 -0700
> Subject: Re: How to: Setuptools
> From: rustompmody at gmail.com
> To: python-list at python.org
>
> On May 28, 6:45 am, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
> wrote:
>> curl -Ohttp://peak.telecommunity.com/dist/ez_setup.py
>> python ez_setup.py
>
> Curl comes built into windows??

No, but you can get it from http://curl.haxx.se/download.html

> Does not seem so...
> http://serverfault.com/questions/483754/is-there-a-built-in-command-line-tool-under-windows-like-wget-curl
>
> Also given that the question clearly says 'I dont know what it means
> to "run it" '
> I think your two lines could be too cryptic :-)

Perhaps, my grandma used to think English is very cryptic. ;)

> To the OP: Sorry I am not being very helpful to you -- I am not on
> windows now and dont know these commands offhand
>
> I am sure someone else will chime in..
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From rustompmody at gmail.com  Mon May 27 23:54:53 2013
From: rustompmody at gmail.com (rusi)
Date: Mon, 27 May 2013 20:54:53 -0700 (PDT)
Subject: How to: Setuptools
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>,
	<mailman.2275.1369705511.3114.python-list@python.org>,
	<88d4a817-f991-4599-927f-5b1f9804aa49@ve4g2000pbb.googlegroups.com>
	<mailman.2277.1369710387.3114.python-list@python.org>
Message-ID: <452a2e20-6c64-4761-9da0-41ccf9a4fa6c@z10g2000pbn.googlegroups.com>

On May 28, 8:06?am, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
wrote:
> ----------------------------------------
>
> > Date: Mon, 27 May 2013 19:57:47 -0700
> > Subject: Re: How to: Setuptools
> > From: rustompm... at gmail.com
> > To: python-l... at python.org
>
> > On May 28, 6:45 am, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
> > wrote:
> >> curl -Ohttp://peak.telecommunity.com/dist/ez_setup.py
> >> python ez_setup.py
>
> > Curl comes built into windows??
>
> No, but you can get it fromhttp://curl.haxx.se/download.html

Oooff! Talk of using sledgehammers to crack nuts...

All that is needed is to visit http://peak.telecommunity.com/dist/ez_setup.py
with the browser and to save the file!!


From carlosnepomuceno at outlook.com  Tue May 28 00:09:39 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 07:09:39 +0300
Subject: How to: Setuptools
In-Reply-To: <452a2e20-6c64-4761-9da0-41ccf9a4fa6c@z10g2000pbn.googlegroups.com>
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>, ,
	<mailman.2275.1369705511.3114.python-list@python.org>, ,
	<88d4a817-f991-4599-927f-5b1f9804aa49@ve4g2000pbb.googlegroups.com>,
	<mailman.2277.1369710387.3114.python-list@python.org>,
	<452a2e20-6c64-4761-9da0-41ccf9a4fa6c@z10g2000pbn.googlegroups.com>
Message-ID: <BLU176-W7E6EB2CDCC53CC2A9283DD7970@phx.gbl>

----------------------------------------
> Date: Mon, 27 May 2013 20:54:53 -0700
> Subject: Re: How to: Setuptools
> From: rustompmody at gmail.com
[...]
>
> Oooff! Talk of using sledgehammers to crack nuts...
>
> All that is needed is to visit http://peak.telecommunity.com/dist/ez_setup.py
> with the browser and to save the file!!

Can you show me how to do that from a batch file? Please... 		 	   		  

From rustompmody at gmail.com  Tue May 28 00:26:21 2013
From: rustompmody at gmail.com (rusi)
Date: Mon, 27 May 2013 21:26:21 -0700 (PDT)
Subject: How to: Setuptools
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>, ,
	<mailman.2275.1369705511.3114.python-list@python.org>, ,
	<88d4a817-f991-4599-927f-5b1f9804aa49@ve4g2000pbb.googlegroups.com>,
	<mailman.2277.1369710387.3114.python-list@python.org>,
	<452a2e20-6c64-4761-9da0-41ccf9a4fa6c@z10g2000pbn.googlegroups.com>
	<mailman.2279.1369714182.3114.python-list@python.org>
Message-ID: <5d03e793-4df0-47b8-ac7f-85ab57fc752d@z10g2000pbn.googlegroups.com>

On May 28, 9:09?am, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
wrote:
> ----------------------------------------
>
> > Date: Mon, 27 May 2013 20:54:53 -0700
> > Subject: Re: How to: Setuptools
> > From: rustompm... at gmail.com
> [...]
>
> > Oooff! Talk of using sledgehammers to crack nuts...
>
> > All that is needed is to visithttp://peak.telecommunity.com/dist/ez_setup.py
> > with the browser and to save the file!!
>
> Can you show me how to do that from a batch file? Please...

What in the OP's question translates into a need for a batch-file?

And you are proposing that he downloads curl just to write that batch-
file?!?!

How come that proposal is not subject to the same requirement, viz. I
dont see in your recipe any:
"Here-is-a-batchfile-to-download-curl-without-curl?"


From carlosnepomuceno at outlook.com  Tue May 28 00:59:25 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 04:59:25 -0000
Subject: How to: Setuptools
In-Reply-To: <5d03e793-4df0-47b8-ac7f-85ab57fc752d@z10g2000pbn.googlegroups.com>
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>,
	,,<mailman.2275.1369705511.3114.python-list@python.org>,
	, , <88d4a817-f991-4599-927f-5b1f9804aa49@ve4g2000pbb.googlegroups.com>,
	, <mailman.2277.1369710387.3114.python-list@python.org>, ,
	<452a2e20-6c64-4761-9da0-41ccf9a4fa6c@z10g2000pbn.googlegroups.com>,
	<mailman.2279.1369714182.3114.python-list@python.org>,
	<5d03e793-4df0-47b8-ac7f-85ab57fc752d@z10g2000pbn.googlegroups.com>
Message-ID: <BLU176-W186CE04271EA363417F46DD7970@phx.gbl>

----------------------------------------
> Date: Mon, 27 May 2013 21:26:21 -0700
> Subject: Re: How to: Setuptools
> From: rustompmody at gmail.com
> To: python-list at python.org
>
> On May 28, 9:09 am, Carlos Nepomuceno <carlosnepomuc... at outlook.com>
> wrote:
>> ----------------------------------------
>>
>>> Date: Mon, 27 May 2013 20:54:53 -0700
>>> Subject: Re: How to: Setuptools
>>> From: rustompm... at gmail.com
>> [...]
>>
>>> Oooff! Talk of using sledgehammers to crack nuts...
>>
>>> All that is needed is to visithttp://peak.telecommunity.com/dist/ez_setup.py
>>> with the browser and to save the file!!
>>
>> Can you show me how to do that from a batch file? Please...
>
> What in the OP's question translates into a need for a batch-file?
>
> And you are proposing that he downloads curl just to write that batch-
> file?!?!
>
> How come that proposal is not subject to the same requirement, viz. I
> dont see in your recipe any:
> "Here-is-a-batchfile-to-download-curl-without-curl?"
> --
> http://mail.python.org/mailman/listinfo/python-list

So, you don't know how to download from a batch file? 		 	   		  

From rustompmody at gmail.com  Tue May 28 08:03:53 2013
From: rustompmody at gmail.com (rusi)
Date: Tue, 28 May 2013 05:03:53 -0700 (PDT)
Subject: How to: Setuptools
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
Message-ID: <22b6ddfe-100f-4ff5-853b-9ec4e2232e7a@h9g2000pbr.googlegroups.com>

On May 28, 6:32?am, ray <r... at aarden.us> wrote:
> I would like to use easy_install, but can't figure out how to install it.
>
> I have 64-bit Python 2.7.5 on Windows 7.
>
> Following the instructions onhttps://pypi.python.org/pypi/setuptools, it says:
> Download ez_setup.py and run it; it will download the appropriate .egg file and install it for you. (Currently, the provided .exe installer does not support 64-bit versions of Python for Windows, due to a distutils installer compatibility issue
>
> Being new to Python, I don't know what it means to "run it". ?I am not sure what I am looking at when I open it as the first line is "#!python".
>
> Looking down into the content of ez_setup.py, I find:
> 'setuptools-0.6c10-py2.6.egg':
> but there is no entry
> 'setuptools-0.6c10-py2.7.egg':
>
> Searching for it, I found a version at:https://pypi.python.org/packages/2.7/s/setuptools/
>
> This appeared to be a linux version, the first line is:
> #!/bin/sh
> and the content seems to be encoded.
>
> There is an exe athttps://pypi.python.org/pypi/setuptools, but the
> instructions on the page state the .exe won't work for 64-bit installs.
>
> Ray

Since there seems to be no response to this, let me try (even though I
am not on windows)
Just point your browser at the link
http://peak.telecommunity.com/dist/ez_setup.py
And save the file ez_setup.py

The more windows-y way of running this is to right-click this and edit
the run-with in some way that I dont have at my finger-tips.

The more old-fashioned way is to start a dos-box (run cmd.exe)
navigate to the directory where the ez_setup.py is saved
from there run the command:
python ez_setup.py

Do that and report back on what happened



From breamoreboy at yahoo.co.uk  Tue May 28 08:26:22 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 28 May 2013 13:26:22 +0100
Subject: How to: Setuptools
In-Reply-To: <22b6ddfe-100f-4ff5-853b-9ec4e2232e7a@h9g2000pbr.googlegroups.com>
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
	<22b6ddfe-100f-4ff5-853b-9ec4e2232e7a@h9g2000pbr.googlegroups.com>
Message-ID: <ko27oo$249$1@ger.gmane.org>

On 28/05/2013 13:03, rusi wrote:
> On May 28, 6:32 am, ray <r... at aarden.us> wrote:
>> I would like to use easy_install, but can't figure out how to install it.
>>
>> I have 64-bit Python 2.7.5 on Windows 7.
>>
>> Following the instructions onhttps://pypi.python.org/pypi/setuptools, it says:
>> Download ez_setup.py and run it; it will download the appropriate .egg file and install it for you. (Currently, the provided .exe installer does not support 64-bit versions of Python for Windows, due to a distutils installer compatibility issue
>>
>> Being new to Python, I don't know what it means to "run it".  I am not sure what I am looking at when I open it as the first line is "#!python".
>>
>> Looking down into the content of ez_setup.py, I find:
>> 'setuptools-0.6c10-py2.6.egg':
>> but there is no entry
>> 'setuptools-0.6c10-py2.7.egg':
>>
>> Searching for it, I found a version at:https://pypi.python.org/packages/2.7/s/setuptools/
>>
>> This appeared to be a linux version, the first line is:
>> #!/bin/sh
>> and the content seems to be encoded.
>>
>> There is an exe athttps://pypi.python.org/pypi/setuptools, but the
>> instructions on the page state the .exe won't work for 64-bit installs.
>>
>> Ray
>
> Since there seems to be no response to this, let me try (even though I
> am not on windows)
> Just point your browser at the link
> http://peak.telecommunity.com/dist/ez_setup.py
> And save the file ez_setup.py
>
> The more windows-y way of running this is to right-click this and edit
> the run-with in some way that I dont have at my finger-tips.

Do this, something goes wrong, no output to see.

>
> The more old-fashioned way is to start a dos-box (run cmd.exe)
> navigate to the directory where the ez_setup.py is saved
> from there run the command:
> python ez_setup.py

Do this, something goes wrong, output in front of you.

>
> Do that and report back on what happened
>

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From ray at aarden.us  Tue May 28 09:05:51 2013
From: ray at aarden.us (ray)
Date: Tue, 28 May 2013 06:05:51 -0700 (PDT)
Subject: How to: Setuptools
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
	<22b6ddfe-100f-4ff5-853b-9ec4e2232e7a@h9g2000pbr.googlegroups.com>
	<mailman.2294.1369743978.3114.python-list@python.org>
Message-ID: <1495a8dd-bbf5-4dda-8733-89d6db0240f1@g8g2000yqa.googlegroups.com>

On May 28, 7:26?am, Mark Lawrence <breamore... at yahoo.co.uk> wrote:
> On 28/05/2013 13:03, rusi wrote:
>
>
>
>
>
> > On May 28, 6:32 am, ray <r... at aarden.us> wrote:
> >> I would like to use easy_install, but can't figure out how to install it.
>
> >> I have 64-bit Python 2.7.5 on Windows 7.
>
> >> Following the instructions onhttps://pypi.python.org/pypi/setuptools, it says:
> >> Download ez_setup.py and run it; it will download the appropriate .egg file and install it for you. (Currently, the provided .exe installer does not support 64-bit versions of Python for Windows, due to a distutils installer compatibility issue
>
> >> Being new to Python, I don't know what it means to "run it". ?I am not sure what I am looking at when I open it as the first line is "#!python".
>
> >> Looking down into the content of ez_setup.py, I find:
> >> 'setuptools-0.6c10-py2.6.egg':
> >> but there is no entry
> >> 'setuptools-0.6c10-py2.7.egg':
>
> >> Searching for it, I found a version at:https://pypi.python.org/packages/2.7/s/setuptools/
>
> >> This appeared to be a linux version, the first line is:
> >> #!/bin/sh
> >> and the content seems to be encoded.
>
> >> There is an exe athttps://pypi.python.org/pypi/setuptools, but the
> >> instructions on the page state the .exe won't work for 64-bit installs.
>
> >> Ray
>
> > Since there seems to be no response to this, let me try (even though I
> > am not on windows)
> > Just point your browser at the link
> >http://peak.telecommunity.com/dist/ez_setup.py
> > And save the file ez_setup.py
>
> > The more windows-y way of running this is to right-click this and edit
> > the run-with in some way that I dont have at my finger-tips.
>
> Do this, something goes wrong, no output to see.
>
>
>
> > The more old-fashioned way is to start a dos-box (run cmd.exe)
> > navigate to the directory where the ez_setup.py is saved
> > from there run the command:
> > python ez_setup.py
>
> Do this, something goes wrong, output in front of you.
>
>
>
> > Do that and report back on what happened
>
> --
> If you're using GoogleCrap??? please read thishttp://wiki.python.org/moin/GoogleGroupsPython.
>
> Mark Lawrence
>
>

The installation fails.  The report stated it could not find the file.
Per:
Looking down into the content of ez_setup.py, I find:
'setuptools-0.6c10-py2.6.egg':
but there is no entry
'setuptools-0.6c10-py2.7.egg':

Since I am trying to install this for Python 2.7, it fails.

Any suggestions?

Ray





From rustompmody at gmail.com  Tue May 28 09:35:23 2013
From: rustompmody at gmail.com (rusi)
Date: Tue, 28 May 2013 06:35:23 -0700 (PDT)
Subject: How to: Setuptools
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
	<22b6ddfe-100f-4ff5-853b-9ec4e2232e7a@h9g2000pbr.googlegroups.com>
	<mailman.2294.1369743978.3114.python-list@python.org>
	<1495a8dd-bbf5-4dda-8733-89d6db0240f1@g8g2000yqa.googlegroups.com>
Message-ID: <c2915aee-a930-4857-9891-697c89889442@be10g2000pbd.googlegroups.com>

On May 28, 6:05?pm, ray <r... at aarden.us> wrote:
> On May 28, 7:26?am, Mark Lawrence <breamore... at yahoo.co.uk> wrote:
>
>
>
>
>
>
>
>
>
> > On 28/05/2013 13:03, rusi wrote:
>
> > > On May 28, 6:32 am, ray <r... at aarden.us> wrote:
> > >> I would like to use easy_install, but can't figure out how to install it.
>
> > >> I have 64-bit Python 2.7.5 on Windows 7.
>
> > >> Following the instructions onhttps://pypi.python.org/pypi/setuptools, it says:
> > >> Download ez_setup.py and run it; it will download the appropriate .egg file and install it for you. (Currently, the provided .exe installer does not support 64-bit versions of Python for Windows, due to a distutils installer compatibility issue
>
> > >> Being new to Python, I don't know what it means to "run it". ?I am not sure what I am looking at when I open it as the first line is "#!python".
>
> > >> Looking down into the content of ez_setup.py, I find:
> > >> 'setuptools-0.6c10-py2.6.egg':
> > >> but there is no entry
> > >> 'setuptools-0.6c10-py2.7.egg':
>
> > >> Searching for it, I found a version at:https://pypi.python.org/packages/2.7/s/setuptools/
>
> > >> This appeared to be a linux version, the first line is:
> > >> #!/bin/sh
> > >> and the content seems to be encoded.
>
> > >> There is an exe athttps://pypi.python.org/pypi/setuptools, but the
> > >> instructions on the page state the .exe won't work for 64-bit installs.
>
> > >> Ray
>
> > > Since there seems to be no response to this, let me try (even though I
> > > am not on windows)
> > > Just point your browser at the link
> > >http://peak.telecommunity.com/dist/ez_setup.py
> > > And save the file ez_setup.py
>
> > > The more windows-y way of running this is to right-click this and edit
> > > the run-with in some way that I dont have at my finger-tips.
>
> > Do this, something goes wrong, no output to see.
>
> > > The more old-fashioned way is to start a dos-box (run cmd.exe)
> > > navigate to the directory where the ez_setup.py is saved
> > > from there run the command:
> > > python ez_setup.py
>
> > Do this, something goes wrong, output in front of you.
>
> > > Do that and report back on what happened
>
> > --
> > If you're using GoogleCrap??? please read thishttp://wiki.python.org/moin/GoogleGroupsPython.
>
> > Mark Lawrence
>
> The installation fails. ?The report stated it could not find the file.
> Per:
> Looking down into the content of ez_setup.py, I find:
> 'setuptools-0.6c10-py2.6.egg':
> but there is no entry
> 'setuptools-0.6c10-py2.7.egg':
>
> Since I am trying to install this for Python 2.7, it fails.
>
> Any suggestions?
>
> Ray

Mysterious...

If you are in hack mode you could try patching that file with the 2.7
egg name and md5
Both of them here https://pypi.python.org/pypi/setuptools

ie after this line
'setuptools-0.6c11-py2.6.egg': 'bfa92100bd772d5a213eedd356d64086',

add this line
'setuptools-0.6c11-py2.7.egg': 'fe1f997bc722265116870bc7919059ea',

However it maybe a better idea to ask on the distutils mailing list
http://mail.python.org/pipermail/distutils-sig/

[And let us know how/what happened!]


From breamoreboy at yahoo.co.uk  Tue May 28 09:40:05 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 28 May 2013 14:40:05 +0100
Subject: How to: Setuptools
In-Reply-To: <1495a8dd-bbf5-4dda-8733-89d6db0240f1@g8g2000yqa.googlegroups.com>
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
	<22b6ddfe-100f-4ff5-853b-9ec4e2232e7a@h9g2000pbr.googlegroups.com>
	<mailman.2294.1369743978.3114.python-list@python.org>
	<1495a8dd-bbf5-4dda-8733-89d6db0240f1@g8g2000yqa.googlegroups.com>
Message-ID: <ko2c30$n1t$1@ger.gmane.org>

On 28/05/2013 14:05, ray wrote:
>
> The installation fails.  The report stated it could not find the file.
> Per:
> Looking down into the content of ez_setup.py, I find:
> 'setuptools-0.6c10-py2.6.egg':
> but there is no entry
> 'setuptools-0.6c10-py2.7.egg':
>
> Since I am trying to install this for Python 2.7, it fails.
>
> Any suggestions?
>
> Ray
>

Try reading this 
http://stackoverflow.com/questions/3652625/installing-setuptools-on-64-bit-windows 
which refers to this http://www.lfd.uci.edu/~gohlke/pythonlibs/ where 
you can get pip which is an easy_install replacement.  You pays your 
money, you takes your choice :)

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From rustompmody at gmail.com  Tue May 28 09:54:28 2013
From: rustompmody at gmail.com (rusi)
Date: Tue, 28 May 2013 06:54:28 -0700 (PDT)
Subject: How to: Setuptools
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
	<22b6ddfe-100f-4ff5-853b-9ec4e2232e7a@h9g2000pbr.googlegroups.com>
	<mailman.2294.1369743978.3114.python-list@python.org>
	<1495a8dd-bbf5-4dda-8733-89d6db0240f1@g8g2000yqa.googlegroups.com>
	<mailman.2296.1369748403.3114.python-list@python.org>
Message-ID: <739c5344-65d8-4587-a002-83cb66fd797e@pd6g2000pbc.googlegroups.com>

On May 28, 6:40?pm, Mark Lawrence <breamore... at yahoo.co.uk> wrote:
> On 28/05/2013 14:05, ray wrote:
>
>
>
> > The installation fails. ?The report stated it could not find the file.
> > Per:
> > Looking down into the content of ez_setup.py, I find:
> > 'setuptools-0.6c10-py2.6.egg':
> > but there is no entry
> > 'setuptools-0.6c10-py2.7.egg':
>
> > Since I am trying to install this for Python 2.7, it fails.
>
> > Any suggestions?
>
> > Ray
>
> Try reading thishttp://stackoverflow.com/questions/3652625/installing-setuptools-on-6...
> which refers to thishttp://www.lfd.uci.edu/~gohlke/pythonlibs/where
> you can get pip which is an easy_install replacement. ?You pays your
> money, you takes your choice :)

Hmm...
Something new (for me)
Last I knew, pip was the supposed replacement for setuptools and you
had to install setuptools to install pip!!!
Maybe this has changed?? Or its different on windows??


From hermanmu at gmail.com  Tue May 28 16:59:56 2013
From: hermanmu at gmail.com (Michael Herman)
Date: Tue, 28 May 2013 13:59:56 -0700
Subject: How to: Setuptools
In-Reply-To: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
Message-ID: <CA+f8p+zXOv8znG8q5D++jzqo+wPbgKCtifGfeHdq25eXUkfMKg@mail.gmail.com>

I have a great video on how to setup Easy_Install via setuptools as
well as pip - http://www.youtube.com/watch?v=MIHYflJwyLk

On Mon, May 27, 2013 at 6:32 PM, ray <ray at aarden.us> wrote:
>
> I would like to use easy_install, but can't figure out how to install it.
>
> I have 64-bit Python 2.7.5 on Windows 7.
>
> Following the instructions on https://pypi.python.org/pypi/setuptools, it
> says:
> Download ez_setup.py and run it; it will download the appropriate .egg
> file and install it for you. (Currently, the provided .exe installer does
> not support 64-bit versions of Python for Windows, due to a distutils
> installer compatibility issue
>
> Being new to Python, I don't know what it means to "run it".  I am not
> sure what I am looking at when I open it as the first line is "#!python".
>
> Looking down into the content of ez_setup.py, I find:
> 'setuptools-0.6c10-py2.6.egg':
> but there is no entry
> 'setuptools-0.6c10-py2.7.egg':
>
> Searching for it, I found a version at:
> https://pypi.python.org/packages/2.7/s/setuptools/
>
> This appeared to be a linux version, the first line is:
> #!/bin/sh
> and the content seems to be encoded.
>
> There is an exe at https://pypi.python.org/pypi/setuptools, but the
> instructions on the page state the .exe won't work for 64-bit installs.
>
> Ray
>
> --
> http://mail.python.org/mailman/listinfo/python-list


From ray at aarden.us  Tue May 28 22:11:10 2013
From: ray at aarden.us (ray)
Date: Tue, 28 May 2013 19:11:10 -0700 (PDT)
Subject: How to:  Setuptools
In-Reply-To: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
References: <bf45fdb5-e980-4828-b664-86093c030cc9@googlegroups.com>
Message-ID: <9e1a70de-85d8-4f73-b0ad-8f0babcdca84@googlegroups.com>

On Monday, May 27, 2013 8:32:43 PM UTC-5, ray wrote:
> I would like to use easy_install, but can't figure out how to install it.
> 
> 
> 
> I have 64-bit Python 2.7.5 on Windows 7.  
> 
> 
> 
> Following the instructions on https://pypi.python.org/pypi/setuptools, it says:
> 
> Download ez_setup.py and run it; it will download the appropriate .egg file and install it for you. (Currently, the provided .exe installer does not support 64-bit versions of Python for Windows, due to a distutils installer compatibility issue
> 
> 
> 
> Being new to Python, I don't know what it means to "run it".  I am not sure what I am looking at when I open it as the first line is "#!python".
> 
> 
> 
> Looking down into the content of ez_setup.py, I find:
> 
> 'setuptools-0.6c10-py2.6.egg':
> 
> but there is no entry
> 
> 'setuptools-0.6c10-py2.7.egg':
> 
> 
> 
> Searching for it, I found a version at:
> 
> https://pypi.python.org/packages/2.7/s/setuptools/
> 
> 
> 
> This appeared to be a linux version, the first line is:
> 
> #!/bin/sh
> 
> and the content seems to be encoded.
> 
> 
> 
> There is an exe at https://pypi.python.org/pypi/setuptools, but the 
> 
> instructions on the page state the .exe won't work for 64-bit installs.
> 
> 
> 
> Ray


I looked through distutils-sig/ .  There were many finding the problem.  There is a solution using Setuptools 2.7 bdist_wininst - http://groups.google.com/group/distutils-sig/browse_thread/thread/6107d5c9044c3f37/4d1a53f9e8fb7d20?hl=en&lnk=gst&q=Setuptools+2.7+bdist_wininst> 

It wasn't clear on where to run things from nor did it address the missing 2.7 reference.

The reference - http://www.lfd.uci.edu/~gohlke/pythonlibs/ 
has a 64 bit installer -  distribute-0.6.43.win-amd64-py2.7.exe.  It ran without error reports.

This all was to install netwokx.  That installed without error.

Ray


From dia.sussex at gmail.com  Tue May 28 06:00:42 2013
From: dia.sussex at gmail.com (Debbie)
Date: Tue, 28 May 2013 03:00:42 -0700 (PDT)
Subject: Python for IPSA (Power flow analysis)
Message-ID: <6288a409-db46-4987-91a7-2f3dd65b42dc@googlegroups.com>

Hi there,
I am new to Python, and wondering if you could help me with python based coding for the IPSA (Power system analysis software). I have a electrical distribution network with generators, buses and loads, on which I am performing the load flow analysis every 1 hour for a period of 1 year. 

The code to perform instantaneous load/power flow analysis is given below. I need to modify it such that I can perform this load flow analysis every 1 hour for a period of 1 year. Please help.

from ipsa import *

ipsasys = IscInterface()
net = ipsasys.ReadFile("refinery.iif")
bok = net.DoLoadFlow();
if bok:
    busbars = net.GetBusbars()
    print "Load Flow results:"
    print ""
    print "BusName     Vmag(kV)"
    print "===================="
    for bus in busbars.itervalues():
        name = bus.GetName()
        vm = bus.GetVoltageMagnitudekV()
        res = "%-8s  %10.5f" % (name, vm)
        print res
else:
    print "Load Flow failed!"

Regards,
Debbie



From davea at davea.name  Tue May 28 07:14:37 2013
From: davea at davea.name (Dave Angel)
Date: Tue, 28 May 2013 07:14:37 -0400
Subject: Python for IPSA (Power flow analysis)
In-Reply-To: <6288a409-db46-4987-91a7-2f3dd65b42dc@googlegroups.com>
References: <6288a409-db46-4987-91a7-2f3dd65b42dc@googlegroups.com>
Message-ID: <51A4919D.7090200@davea.name>

On 05/28/2013 06:00 AM, Debbie wrote:
> Hi there,
> I am new to Python,

Welcome.  Could you tell us a little about yourself, such as whether 
you've experience in a few other languages, or if Python is your first 
programming experience?  Also, what version of Python (presumably 2.7 or 
2.6) and what OS ?

> and wondering if you could help me with python based coding for the IPSA (Power system analysis software). I have a electrical distribution network with generators, buses and loads, on which I am performing the load flow analysis every 1 hour for a period of 1 year.
>
> The code to perform instantaneous load/power flow analysis is given below. I need to modify it such that I can perform this load flow analysis every 1 hour for a period of 1 year. Please help.
>
> from ipsa import *

I have no idea what functionality is in ipsa, so this whole message is a 
guess.  First question is whether the ReadFile() below and the 
DoLoadFlow() read the whole year's data, or data for a particular hour. 
  And if the latter, how do you get the next set of data?


>
> ipsasys = IscInterface()
> net = ipsasys.ReadFile("refinery.iif")
> bok = net.DoLoadFlow();
> if bok:
>      busbars = net.GetBusbars()
>      print "Load Flow results:"
>      print ""
>      print "BusName     Vmag(kV)"
>      print "===================="
>      for bus in busbars.itervalues():
>          name = bus.GetName()
>          vm = bus.GetVoltageMagnitudekV()
>          res = "%-8s  %10.5f" % (name, vm)
>          print res
> else:
>      print "Load Flow failed!"
>
> Regards,
> Debbie
>

First you want to make a function to print out a particular hour's data. 
  That might turn out to be something like:

def one_hour(net):
     busbars = net.GetBusbars()
     print "Load Flow results:"
     print ""
     print "BusName     Vmag(kV)"
     print "===================="
     for bus in busbars.itervalues():
         name = bus.GetName()
         vm = bus.GetVoltageMagnitudekV()
         res = "%-8s  %10.5f" % (name, vm)
         print res

(Just pasted from your code, I added in the probable parameter to the 
definition)

Now your main function might be something like:


def main(filename):
     ipsasys = IscInterface()
     net = ipsasys.ReadFile(filename)

     #if net gets you data for one hour, figure out how
     #to get the data for the whole year, in the form
     #of a list or an iterator called nets

     bok = net.DoLoadFlow();
     if bok:
         for net in nets:
             one_hour(net)

     else:
         print "Load Flow failed!"


#and your top-level code is:
main("refinery.iif")


As to ordering in the source file, put the import first:
    from ipsa import *

then your function definitions one_hour() and main(), then
your top-level code.

-- 
DaveA


From spam at capuchin.co.uk  Tue May 28 08:08:32 2013
From: spam at capuchin.co.uk (Robert Marshall)
Date: Tue, 28 May 2013 13:08:32 +0100
Subject: Python for IPSA (Power flow analysis)
References: <6288a409-db46-4987-91a7-2f3dd65b42dc@googlegroups.com>
Message-ID: <87zjvfnw73.fsf@capuchin.co.uk>

On Tue, May 28 2013, Debbie <dia.sussex at gmail.com> wrote:

> Hi there, I am new to Python, and wondering if you could help me with
> python based coding for the IPSA (Power system analysis software). I
> have a electrical distribution network with generators, buses and
> loads, on which I am performing the load flow analysis every 1 hour
> for a period of 1 year.
>
> The code to perform instantaneous load/power flow analysis is given
> below. I need to modify it such that I can perform this load flow
> analysis every 1 hour for a period of 1 year. Please help.
>
> from ipsa import *
>
> ipsasys = IscInterface()
> net = ipsasys.ReadFile("refinery.iif")
> bok = net.DoLoadFlow();
> if bok:
>     busbars = net.GetBusbars()
...
>     for bus in busbars.itervalues():
>         name = bus.GetName()
..
> else:
>     print "Load Flow failed!"
>

I think Dave's suggestions are useful, a few years ago I was one of the
developers for the IPSA python API, I'm not sure how things have moved
on since then but you need somewhere to incorporate some time modelling
- at the moment I'm not sure how and if that was done. In any case I
doubt if the simulation would give rigourous results over a simulation
period of that length

Is what you really have  a set of iif files with current voltages over a
set of periods within that year, if so you need to iterate though those,
loading each one and doing individual load flows.

IPSA has a linkedin discussion group and current IPSA developers will I
think respond to you there (if you have an account)

Robert
-- 
La grenouille songe..dans son ch?teau d'eau
Links and things http://rmstar.blogspot.com/


From steve.ingram at tnei.co.uk  Wed May 29 04:51:36 2013
From: steve.ingram at tnei.co.uk (steve.ingram at tnei.co.uk)
Date: Wed, 29 May 2013 01:51:36 -0700 (PDT)
Subject: Python for IPSA (Power flow analysis)
In-Reply-To: <6288a409-db46-4987-91a7-2f3dd65b42dc@googlegroups.com>
References: <6288a409-db46-4987-91a7-2f3dd65b42dc@googlegroups.com>
Message-ID: <09f09e22-626c-4b49-a80f-8259bdf2adac@googlegroups.com>

On Tuesday, May 28, 2013 11:00:42 AM UTC+1, Debbie wrote:
> Hi there,
> 
> I am new to Python, and wondering if you could help me with python based coding for the IPSA (Power system analysis software). I have a electrical distribution network with generators, buses and loads, on which I am performing the load flow analysis every 1 hour for a period of 1 year. 
> 
> 
> 
> The code to perform instantaneous load/power flow analysis is given below. I need to modify it such that I can perform this load flow analysis every 1 hour for a period of 1 year. Please help.
> 
> 
> 
> from ipsa import *
> 
> 
> 
> ipsasys = IscInterface()
> 
> net = ipsasys.ReadFile("refinery.iif")
> 
> bok = net.DoLoadFlow();
> 
> if bok:
> 
>     busbars = net.GetBusbars()
> 
>     print "Load Flow results:"
> 
>     print ""
> 
>     print "BusName     Vmag(kV)"
> 
>     print "===================="
> 
>     for bus in busbars.itervalues():
> 
>         name = bus.GetName()
> 
>         vm = bus.GetVoltageMagnitudekV()
> 
>         res = "%-8s  %10.5f" % (name, vm)
> 
>         print res
> 
> else:
> 
>     print "Load Flow failed!"
> 
> 
> 
> Regards,
> 
> Debbie

Hi Debbie,

Just found your question. I work for Ipsa and, among other things, provide support for the scripting side.

The quickest way to achieve what you want is to adjust the loads on the network and perform a load flow. The sequence would be roughly as follows;

for hours in year():
    # set load values
    loads = net.GetLoads()
    for load in loads().itervalues:
        # set new value for each load to represent the next hour of data
        load.SetDValue(IscLoad.ReactiveMVAr, next_MVAr_value)
        load.SetDValue(IscLoad.RealMW, next_MW_value)

        net.DoLoadFlow()
        # do something with these results
 
The above code obviously won't work and will need tweaking, but should give you the idea. The next version of Ipsa (2.3.2) will have load profiles in so will give a different way of achieving the same results, as well as speed improvements.

As Robert mentioned, the best place for Ipsa support is to go onto the website (www.ipsa-power.com) and check the Support of Education pages or check the LinkedIn group Ipsa Power Software Group at http://www.linkedin.com/groups/IPSA-Power-Software-4860907

Hope this helps,

Steve


From notreal at earthlink.net  Tue May 28 11:32:06 2013
From: notreal at earthlink.net (JackM)
Date: Tue, 28 May 2013 11:32:06 -0400
Subject: IndentationError: expected an indented block but it's there
Message-ID: <V54pt.161708$Zp1.55817@en-nntp-15.dc1.easynews.com>

Having a problem getting a py script to execute. Got this error:

File "/scripts/blockIPv4.py", line 19
     ip = line.split(';')[0]
      ^
IndentationError: expected an indented block


I'm perplexed because the code that the error refers to *is* indented:



with open('/var/www/html/mydomain.com/banlist.txt','r') as inFile:
     for line in inFile.readlines():
         ip = line.split(';')[0]
         output = os.popen( '/etc/sysconfig/iptables -A INPUT -s ' + ip 
+ ' -j REJECT' )
         logFile.write(ip+' - Has been blocked\n')


What am I missing here?




-- 
My email address on the header is a non-monitored spam catching account. 
I can be reached via http://www.wvnh.net/contact.htm


From torriem at gmail.com  Tue May 28 11:55:52 2013
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 28 May 2013 09:55:52 -0600
Subject: IndentationError: expected an indented block but it's there
In-Reply-To: <V54pt.161708$Zp1.55817@en-nntp-15.dc1.easynews.com>
References: <V54pt.161708$Zp1.55817@en-nntp-15.dc1.easynews.com>
Message-ID: <51A4D388.8090109@gmail.com>

On 05/28/2013 09:32 AM, JackM wrote:
> Having a problem getting a py script to execute. Got this error:
> 
> File "/scripts/blockIPv4.py", line 19
>      ip = line.split(';')[0]
>       ^
> IndentationError: expected an indented block
> I'm perplexed because the code that the error refers to *is* indented:
> with open('/var/www/html/mydomain.com/banlist.txt','r') as inFile:
>      for line in inFile.readlines():
>          ip = line.split(';')[0]
>          output = os.popen( '/etc/sysconfig/iptables -A INPUT -s ' + ip 
> + ' -j REJECT' )
>          logFile.write(ip+' - Has been blocked\n')
> 
> 
> What am I missing here?

Indentation has to be consistent.  likely the for line is indented with
spaces and the next line with a tab.  You can use tabs and spaces, but
you have to be consistent with how you use them.  IE if level 1 is
indented with spaces, then level 2 has to be indented with spaces up to
level 1 as well.  Hope that makes sense.





From steve+comp.lang.python at pearwood.info  Tue May 28 12:01:14 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 28 May 2013 16:01:14 GMT
Subject: IndentationError: expected an indented block but it's there
References: <V54pt.161708$Zp1.55817@en-nntp-15.dc1.easynews.com>
Message-ID: <51a4d4ca$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Tue, 28 May 2013 11:32:06 -0400, JackM wrote:

> Having a problem getting a py script to execute. Got this error:
> 
> File "/scripts/blockIPv4.py", line 19
>      ip = line.split(';')[0]
>       ^
> IndentationError: expected an indented block
> 
> 
> I'm perplexed because the code that the error refers to *is* indented:

Whenever you get perplexing indentation errors, suspect an inconsistency 
due to mixed tabs and spaces.

Tabs good. Spaces good. Tabs and spaces together, bad.

You can run the tabnanny module over your source code:

python -m tabnanny  <file-or-directory>


to convert indentation to all spaces.


-- 
Steven


From __peter__ at web.de  Tue May 28 12:19:47 2013
From: __peter__ at web.de (Peter Otten)
Date: Tue, 28 May 2013 18:19:47 +0200
Subject: IndentationError: expected an indented block but it's there
References: <V54pt.161708$Zp1.55817@en-nntp-15.dc1.easynews.com>
Message-ID: <ko2let$73u$1@ger.gmane.org>

JackM wrote:

> Having a problem getting a py script to execute. Got this error:
> 
> File "/scripts/blockIPv4.py", line 19
>      ip = line.split(';')[0]
>       ^
> IndentationError: expected an indented block
> 
> 
> I'm perplexed because the code that the error refers to *is* indented:
> 
> 
> 
> with open('/var/www/html/mydomain.com/banlist.txt','r') as inFile:
>      for line in inFile.readlines():
>          ip = line.split(';')[0]
>          output = os.popen( '/etc/sysconfig/iptables -A INPUT -s ' + ip
> + ' -j REJECT' )
>          logFile.write(ip+' - Has been blocked\n')
> 
> 
> What am I missing here?

If you are mixing tabs and spaces to indent your code and have your editor 
configured with a tab width other than eight your code may look correct when 
it isn't. A simulation in the interactive interpreter:

The actual file contents:

>>> s = "if 1:\n\tif 2:\n    \tprint 'hi'"

What you see:

>>> print s.expandtabs(4)
if 1:
    if 2:
        print 'hi'
>>> exec s.expandtabs(4)
hi

What Python "sees":

>>> print s.expandtabs(8)
if 1:
        if 2:
        print 'hi'
>>> exec s
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 3
    print 'hi'
        ^
IndentationError: expected an indented block

Solution: configure your editor to use four spaces for indentation.



From rosuav at gmail.com  Tue May 28 12:31:47 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 29 May 2013 02:31:47 +1000
Subject: IndentationError: expected an indented block but it's there
In-Reply-To: <ko2let$73u$1@ger.gmane.org>
References: <V54pt.161708$Zp1.55817@en-nntp-15.dc1.easynews.com>
	<ko2let$73u$1@ger.gmane.org>
Message-ID: <CAPTjJmod5Yus_bOfONBysO=P3Wq4AUskKY0wMyP4NgHR6xE6zw@mail.gmail.com>

On Wed, May 29, 2013 at 2:19 AM, Peter Otten <__peter__ at web.de> wrote:
> Solution: configure your editor to use four spaces for indentation.

ITYM eight spaces. But the real solution is to not mix tabs and
spaces. Stick to one or the other and you're safe.

ChrisA


From __peter__ at web.de  Tue May 28 12:53:17 2013
From: __peter__ at web.de (Peter Otten)
Date: Tue, 28 May 2013 18:53:17 +0200
Subject: IndentationError: expected an indented block but it's there
References: <V54pt.161708$Zp1.55817@en-nntp-15.dc1.easynews.com>
	<ko2let$73u$1@ger.gmane.org>
	<CAPTjJmod5Yus_bOfONBysO=P3Wq4AUskKY0wMyP4NgHR6xE6zw@mail.gmail.com>
Message-ID: <ko2ndo$105$1@ger.gmane.org>

Chris Angelico wrote:

> On Wed, May 29, 2013 at 2:19 AM, Peter Otten <__peter__ at web.de> wrote:
>> Solution: configure your editor to use four spaces for indentation.
> 
> ITYM eight spaces. 

I meant: one hit of the Tab key should add spaces up to the next multiple of 
four. Which implies

> But the real solution is to not mix tabs and
> spaces. Stick to one or the other and you're safe.




From rosuav at gmail.com  Wed May 29 03:59:30 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 29 May 2013 17:59:30 +1000
Subject: IndentationError: expected an indented block but it's there
In-Reply-To: <ko2ndo$105$1@ger.gmane.org>
References: <V54pt.161708$Zp1.55817@en-nntp-15.dc1.easynews.com>
	<ko2let$73u$1@ger.gmane.org>
	<CAPTjJmod5Yus_bOfONBysO=P3Wq4AUskKY0wMyP4NgHR6xE6zw@mail.gmail.com>
	<ko2ndo$105$1@ger.gmane.org>
Message-ID: <CAPTjJmqaiUfHWDVD-wLUc=qcgvuiB_08j4F1NBc0YL_2an=ijQ@mail.gmail.com>

On Wed, May 29, 2013 at 2:53 AM, Peter Otten <__peter__ at web.de> wrote:
> Chris Angelico wrote:
>
>> On Wed, May 29, 2013 at 2:19 AM, Peter Otten <__peter__ at web.de> wrote:
>>> Solution: configure your editor to use four spaces for indentation.
>>
>> ITYM eight spaces.
>
> I meant: one hit of the Tab key should add spaces up to the next multiple of
> four. Which implies
>
>> But the real solution is to not mix tabs and
>> spaces. Stick to one or the other and you're safe.

Sure. If you configure your tab *key* to not insert a tab *character*,
then you're fine. Or alternatively, if you always use \t for
indentation, you can tweak the displayed width of it. (Or, as I do,
just let it be eight wide. On today's screens that's not much of a
problem.)

ChrisA


From wolfgang.maier at biologie.uni-freiburg.de  Tue May 28 13:27:04 2013
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Tue, 28 May 2013 17:27:04 +0000 (UTC)
Subject: usage of =?utf-8?b?b3MucG9zaXhfZmFkdmlzZQ==?=
Message-ID: <loom.20130528T191108-707@post.gmane.org>

Dear all,
I was just experimenting for the first time with os.posix_fadvise(), which
is new in Python3.3 . I'm reading from a really huge file (several GB) and I
want to use the data only once, so I don't want OS-level page caching. I
tried os.posix_fadvise with the os.POSIX_FADV_NOREUSE and with the
os.POSIX_FADV_DONTNEED flags, but neither seemed to have any effect on the
caching behaviour of Ubuntu (still uses all available memory to page cache
my I/O).
Specifically, I was trying this:

import os
fd = os.open('myfile', os.O_RDONLY)
# wasn't sure about the len parameter in fadvise,
# so thought I just use it on the first 4GB
os.posix_fadvise(fd, 0, 4000000000, os.POSIX_FADV_NOREUSE) # or DONTNEED

then reading from the file with os.read() .

By its very nature, I suppose posix_fadvise's effects will be OS-dependent,
so my question is whether the lack of effect I'm observing is something
Ubuntu-specific, or if I'm just using it in a wrong way.

Any help is greatly appreciated!
Best,
Wolfgang 



From solipsis at pitrou.net  Wed May 29 06:51:58 2013
From: solipsis at pitrou.net (Antoine Pitrou)
Date: Wed, 29 May 2013 10:51:58 +0000 (UTC)
Subject: usage of =?utf-8?b?b3MucG9zaXhfZmFkdmlzZQ==?=
References: <loom.20130528T191108-707@post.gmane.org>
Message-ID: <loom.20130529T124827-932@post.gmane.org>


Hi,

Wolfgang Maier <wolfgang.maier <at> biologie.uni-freiburg.de> writes:
> 
> Dear all,
> I was just experimenting for the first time with os.posix_fadvise(), which
> is new in Python3.3 . I'm reading from a really huge file (several GB) and I
> want to use the data only once, so I don't want OS-level page caching. I
> tried os.posix_fadvise with the os.POSIX_FADV_NOREUSE and with the
> os.POSIX_FADV_DONTNEED flags, but neither seemed to have any effect on the
> caching behaviour of Ubuntu (still uses all available memory to page cache
> my I/O).
> Specifically, I was trying this:
> 
> import os
> fd = os.open('myfile', os.O_RDONLY)
> # wasn't sure about the len parameter in fadvise,
> # so thought I just use it on the first 4GB
> os.posix_fadvise(fd, 0, 4000000000, os.POSIX_FADV_NOREUSE) # or DONTNEED

The Linux version of "man posix_fadvise" probably holds the answer:

"In kernels before 2.6.18, POSIX_FADV_NOREUSE had the same semantics
as POSIX_FADV_WILLNEED.  This was probably a bug; since kernel
2.6.18, this flag is a no-op."

"POSIX_FADV_DONTNEED attempts to free cached pages associated with the
specified region.  This is useful, for example, while streaming large
files.  A program may periodically request the kernel to free cached
data that has already been used, so that more useful cached pages  are
not discarded instead."

So, in summary:

- POSIX_FADV_NOREUSE doesn't do anything on (modern) Linux kernels
- POSIX_FADV_DONTNEED must be called *after* you are done with a range of
  data, not before you read it (note that I haven't tested to confirm it :-))

Regards

Antoine.




From michael at stroeder.com  Mon May 27 04:10:58 2013
From: michael at stroeder.com (=?ISO-8859-1?Q?Michael_Str=F6der?=)
Date: Mon, 27 May 2013 10:10:58 +0200
Subject: ANN: python-ldap 2.4.11
Message-ID: <mailman.2309.1369763784.3114.python-announce-list@python.org>

Find a new release of python-ldap:

  http://pypi.python.org/pypi/python-ldap/2.4.11

python-ldap provides an object-oriented API to access LDAP directory
servers from Python programs. It mainly wraps the OpenLDAP 2.x libs for
that purpose. Additionally it contains modules for other LDAP-related
stuff (e.g. processing LDIF, LDAP URLs and LDAPv3 schema).

Project's web site:

  http://www.python-ldap.org/

Ciao, Michael.

----------------------------------------------------------------
Released 2.4.11 2013-05-27

Changes since 2.4.10:

Lib/
* ldap.controls.DecodeControlTuples() now simply ignores
  PyAsn1Error exception raised during decoding malformed
  response control values in case of non-critical controls.
* ldif.LDIFWriter.unparse() does not simply skip empty
  records anymore.


From tunacubes at gmail.com  Tue May 28 14:25:30 2013
From: tunacubes at gmail.com (Matt Graves)
Date: Tue, 28 May 2013 11:25:30 -0700 (PDT)
Subject: String object has no attribute "append"
Message-ID: <8d8143e8-74f3-43a0-9a52-06b60e857984@googlegroups.com>

I receive this error while toying around with Functions...

def pulldata(speclist,speccolumn):
    with open('profiles.csv', 'r') as f:
              reader = csv.reader(f)
              for column in reader:
                 (speclist).append(column[('speccolumn')])

pulldata(speclist = 'numbers', speccolumn = "0")


>Traceback (most recent call last):
>  File "C:\Desktop\Python\CFI\Devices V2\users.py", line 17, in <module>
>    pulldata(speclist = 'numbers', speccolumn = "0")
>  File "C:\Desktop\Python\CFI\Devices V2\users.py", line 16, in pulldata
>    (speclist).append(column[('speccolumn')])
>AttributeError: 'str' object has no attribute 'append'

I'm getting the error because it should say "numbers.append", but it is reading it as "(speclist).append".

This is my first time playing with functions, so be gentle. 


From marduk at python.net  Tue May 28 14:40:05 2013
From: marduk at python.net (marduk at python.net)
Date: Tue, 28 May 2013 14:40:05 -0400
Subject: String object has no attribute "append"
In-Reply-To: <8d8143e8-74f3-43a0-9a52-06b60e857984@googlegroups.com>
References: <8d8143e8-74f3-43a0-9a52-06b60e857984@googlegroups.com>
Message-ID: <1369766405.4997.140661236763125.530A41E5@webmail.messagingengine.com>



On Tue, May 28, 2013, at 02:25 PM, Matt Graves wrote:
> I receive this error while toying around with Functions...
> 
> def pulldata(speclist,speccolumn):
>     with open('profiles.csv', 'r') as f:
>               reader = csv.reader(f)
>               for column in reader:
>                  (speclist).append(column[('speccolumn')])
> 
> pulldata(speclist = 'numbers', speccolumn = "0")
> 
> 
> >Traceback (most recent call last):
> >  File "C:\Desktop\Python\CFI\Devices V2\users.py", line 17, in <module>
> >    pulldata(speclist = 'numbers', speccolumn = "0")
> >  File "C:\Desktop\Python\CFI\Devices V2\users.py", line 16, in pulldata
> >    (speclist).append(column[('speccolumn')])
> >AttributeError: 'str' object has no attribute 'append'
> 
> I'm getting the error because it should say "numbers.append", but it is
> reading it as "(speclist).append".

Because it indeed says "(speclist).append"... am I missing something?



From ian.g.kelly at gmail.com  Tue May 28 14:41:37 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 28 May 2013 12:41:37 -0600
Subject: String object has no attribute "append"
In-Reply-To: <8d8143e8-74f3-43a0-9a52-06b60e857984@googlegroups.com>
References: <8d8143e8-74f3-43a0-9a52-06b60e857984@googlegroups.com>
Message-ID: <CALwzidkQgVG9=NyNnOz1x-irtg1rYcr4eU3q82GpyC0LuLsq-g@mail.gmail.com>

On Tue, May 28, 2013 at 12:25 PM, Matt Graves <tunacubes at gmail.com> wrote:
> I receive this error while toying around with Functions...
>
> def pulldata(speclist,speccolumn):
>     with open('profiles.csv', 'r') as f:
>               reader = csv.reader(f)
>               for column in reader:
>                  (speclist).append(column[('speccolumn')])
>
> pulldata(speclist = 'numbers', speccolumn = "0")
>
>
>>Traceback (most recent call last):
>>  File "C:\Desktop\Python\CFI\Devices V2\users.py", line 17, in <module>
>>    pulldata(speclist = 'numbers', speccolumn = "0")
>>  File "C:\Desktop\Python\CFI\Devices V2\users.py", line 16, in pulldata
>>    (speclist).append(column[('speccolumn')])
>>AttributeError: 'str' object has no attribute 'append'
>
> I'm getting the error because it should say "numbers.append", but it is reading it as "(speclist).append".
>
> This is my first time playing with functions, so be gentle.

It looks like you're trying to pass in a list called 'numbers' into
the pulldata function, but that is not what's happening.  Because of
the single quotes you have around numbers, you are passing in the
/string/ 'numbers' and calling it 'speclist' instead.  The same goes
for speccolumn as well; I think you mean to pass in the integer 0, but
you're passing in the string "0" instead.  Try it without the quotes:

pulldata(speclist = numbers, speccolumn = 0)


From ian.g.kelly at gmail.com  Tue May 28 14:43:10 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 28 May 2013 12:43:10 -0600
Subject: String object has no attribute "append"
In-Reply-To: <CALwzidkQgVG9=NyNnOz1x-irtg1rYcr4eU3q82GpyC0LuLsq-g@mail.gmail.com>
References: <8d8143e8-74f3-43a0-9a52-06b60e857984@googlegroups.com>
	<CALwzidkQgVG9=NyNnOz1x-irtg1rYcr4eU3q82GpyC0LuLsq-g@mail.gmail.com>
Message-ID: <CALwzidneOw5PRpMu8yh1+0zxbEyEGcgO7qqbf3ktg+7eY4Xw+g@mail.gmail.com>

On Tue, May 28, 2013 at 12:41 PM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Tue, May 28, 2013 at 12:25 PM, Matt Graves <tunacubes at gmail.com> wrote:
>> I receive this error while toying around with Functions...
>>
>> def pulldata(speclist,speccolumn):
>>     with open('profiles.csv', 'r') as f:
>>               reader = csv.reader(f)
>>               for column in reader:
>>                  (speclist).append(column[('speccolumn')])
>>
>> pulldata(speclist = 'numbers', speccolumn = "0")
>>
>>
>>>Traceback (most recent call last):
>>>  File "C:\Desktop\Python\CFI\Devices V2\users.py", line 17, in <module>
>>>    pulldata(speclist = 'numbers', speccolumn = "0")
>>>  File "C:\Desktop\Python\CFI\Devices V2\users.py", line 16, in pulldata
>>>    (speclist).append(column[('speccolumn')])
>>>AttributeError: 'str' object has no attribute 'append'
>>
>> I'm getting the error because it should say "numbers.append", but it is reading it as "(speclist).append".
>>
>> This is my first time playing with functions, so be gentle.
>
> It looks like you're trying to pass in a list called 'numbers' into
> the pulldata function, but that is not what's happening.  Because of
> the single quotes you have around numbers, you are passing in the
> /string/ 'numbers' and calling it 'speclist' instead.  The same goes
> for speccolumn as well; I think you mean to pass in the integer 0, but
> you're passing in the string "0" instead.  Try it without the quotes:
>
> pulldata(speclist = numbers, speccolumn = 0)

And along the same lines, the expression column[('speccolumn')] should
just be column[speccolumn].


From rosuav at gmail.com  Wed May 29 03:54:38 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 29 May 2013 17:54:38 +1000
Subject: String object has no attribute "append"
In-Reply-To: <8d8143e8-74f3-43a0-9a52-06b60e857984@googlegroups.com>
References: <8d8143e8-74f3-43a0-9a52-06b60e857984@googlegroups.com>
Message-ID: <CAPTjJmqzhdhfJTFgABoE-LNPJ_=V4jo_f5EtNoUqLSDM+KB8BA@mail.gmail.com>

On Wed, May 29, 2013 at 4:25 AM, Matt Graves <tunacubes at gmail.com> wrote:
> I receive this error while toying around with Functions...
>
> def pulldata(speclist,speccolumn):
>                  (speclist).append(column[('speccolumn')])
>
> pulldata(speclist = 'numbers', speccolumn = "0")
>
> I'm getting the error because it should say "numbers.append", but it is reading it as "(speclist).append".

Others have answered the immediate problem, but you may find this a
worthwhile read:

http://mail.python.org/pipermail/tutor/2010-December/080505.html

It's an excellent explanation of the way Python passes arguments to functions.

ChrisA


From carlosnepomuceno at outlook.com  Tue May 28 15:46:37 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 22:46:37 +0300
Subject: Python #ifdef
Message-ID: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>

Are there Python 'preprocessor directives'?

I'd like to have something like '#ifdef' to mix code from Python 2 and 3 in a single file.

Is that possible? How? 		 	   		  

From joel.goldstick at gmail.com  Tue May 28 15:49:03 2013
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Tue, 28 May 2013 15:49:03 -0400
Subject: Python #ifdef
In-Reply-To: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
Message-ID: <CAPM-O+x4BdVCD0O3PD+yUwYFNCQpo-xWEz0BP-fWYAsE9a+U_g@mail.gmail.com>

No
On May 28, 2013 3:48 PM, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
wrote:

> Are there Python 'preprocessor directives'?
>
> I'd like to have something like '#ifdef' to mix code from Python 2 and 3
> in a single file.
>
> Is that possible? How?
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From davea at davea.name  Tue May 28 15:57:49 2013
From: davea at davea.name (Dave Angel)
Date: Tue, 28 May 2013 15:57:49 -0400
Subject: Python #ifdef
In-Reply-To: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
Message-ID: <51A50C3D.1090309@davea.name>

On 05/28/2013 03:46 PM, Carlos Nepomuceno wrote:
> Are there Python 'preprocessor directives'?

Python doesn't define a preprocessor, and CPYthon doesn't implement one. 
  Nothing to stop you from doing so, however.
>
> I'd like to have something like '#ifdef' to mix code from Python 2 and 3 in a single file.
>
> Is that possible? How? 		 	   		
>

It's quite possible that you don't need a preprocessor do what you want, 
since Python does much less compile-time checking than C.  Also, it's 
possible to store function objects and module objects in variables, and 
thus to hide many things from the body of the code.

One biggie is print, since that's a reserved word (and a statement) in 
Python 2.x.  But if you're using 2.7 you can use from __future__ import 
print, or something like that, and just use 3.x function semantics.


-- 
DaveA


From neilc at norwich.edu  Tue May 28 16:00:04 2013
From: neilc at norwich.edu (Neil Cerutti)
Date: 28 May 2013 20:00:04 GMT
Subject: Python #ifdef
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2318.1369770916.3114.python-list@python.org>
Message-ID: <b0kgm4F3gs4U1@mid.individual.net>

On 2013-05-28, Joel Goldstick <joel.goldstick at gmail.com> wrote:
>
> No

Yes. More below.

> On May 28, 2013 3:48 PM, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
> wrote:
>> Are there Python 'preprocessor directives'?
>>
>> I'd like to have something like '#ifdef' to mix code from Python 2 and 3
>> in a single file.
>>
>> Is that possible? How?

You need sys.version_info.

For more, see http://python3porting.com/noconv.html

-- 
Neil Cerutti


From carlosnepomuceno at outlook.com  Tue May 28 16:07:39 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 23:07:39 +0300
Subject: Python #ifdef
In-Reply-To: <b0kgm4F3gs4U1@mid.individual.net>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>,
	<mailman.2318.1369770916.3114.python-list@python.org>,
	<b0kgm4F3gs4U1@mid.individual.net>
Message-ID: <BLU176-W47EB6E75063FE93256EAE8D7970@phx.gbl>

Thank you! I made it run like the following. What do you think about that? IS there a better way?



#The following runs on Python 2.7
sc3='''
# Python 3
def original(n):
??? m = 0
??? for b in n.to_bytes(6, 'big'):
??????? m = 256*m + b
??? return m
'''
if sys.version_info[0] == 3:
??? exec(sc3) 		 	   		  

From benjamin.kaplan at case.edu  Tue May 28 16:14:57 2013
From: benjamin.kaplan at case.edu (Benjamin Kaplan)
Date: Tue, 28 May 2013 13:14:57 -0700
Subject: Python #ifdef
In-Reply-To: <BLU176-W47EB6E75063FE93256EAE8D7970@phx.gbl>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2318.1369770916.3114.python-list@python.org>
	<b0kgm4F3gs4U1@mid.individual.net>
	<BLU176-W47EB6E75063FE93256EAE8D7970@phx.gbl>
Message-ID: <CAMuTYXjjPCVMSJU4cfGA-t6LdB7i6R5ATi3c6rFExEhGUKWv1w@mail.gmail.com>

On May 28, 2013 1:10 PM, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
wrote:
>
> Thank you! I made it run like the following. What do you think about
that? IS there a better way?
>
>
>
> #The following runs on Python 2.7
> sc3='''
> # Python 3
> def original(n):
>     m = 0
>     for b in n.to_bytes(6, 'big'):
>         m = 256*m + b
>     return m
> '''
> if sys.version_info[0] == 3:
>     exec(sc3)
> --

No need for exec.

if sys.version_info[0] >= 3:
    def original(n) :
       ...
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From invalid at invalid.invalid  Tue May 28 16:12:59 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 20:12:59 +0000 (UTC)
Subject: Python #ifdef
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2318.1369770916.3114.python-list@python.org>
	<b0kgm4F3gs4U1@mid.individual.net>
	<mailman.2320.1369771667.3114.python-list@python.org>
Message-ID: <ko334b$83c$1@reader1.panix.com>

On 2013-05-28, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:

> Thank you! I made it run like the following. What do you think about
> that? IS there a better way?
>
> #The following runs on Python 2.7
> sc3='''
> # Python 3
> def original(n):
> ??? m = 0
> ??? for b in n.to_bytes(6, 'big'):
> ??????? m = 256*m + b
> ??? return m
> '''
> if sys.version_info[0] == 3:
> ??? exec(sc3) 		 	   		  

You're trying to make this a lot harder than it really is:

if sys.version_info[0] == 3:
    def original(n):
        m = 0
        for b in n.to_bytes(6, 'big'):
            m = 256*m + b
        return m
else:
    def original(n):
        <something else?>
        

-- 
Grant Edwards               grant.b.edwards        Yow! Am I having fun yet?
                                  at               
                              gmail.com            


From carlosnepomuceno at outlook.com  Tue May 28 16:22:40 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 23:22:40 +0300
Subject: Python #ifdef
In-Reply-To: <ko334b$83c$1@reader1.panix.com>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>,
	<mailman.2318.1369770916.3114.python-list@python.org>,
	<b0kgm4F3gs4U1@mid.individual.net>,
	<mailman.2320.1369771667.3114.python-list@python.org>,
	<ko334b$83c$1@reader1.panix.com>
Message-ID: <BLU176-W163A3FC339C409E765BA5DD7970@phx.gbl>

----------------------------------------
> From: invalid at invalid.invalid
> Subject: Re: Python #ifdef
[...]
> You're trying to make this a lot harder than it really is:
>
> if sys.version_info[0] == 3:
> def original(n):
> m = 0
> for b in n.to_bytes(6, 'big'):
> m = 256*m + b
> return m
> else:
> def original(n):
> <something else?>
>
>
> --
> Grant Edwards grant.b.edwards Yow! Am I having fun yet?
> at
> gmail.com

Haha! That's it!!!

Just realized how funny this can be: ;)

### never to be opened ###
def pandoras_box(v):
??? return v/0.0

if customer_didnt_pay():
??? pandoras_box()

#lol 		 	   		  

From fabiosantosart at gmail.com  Tue May 28 16:34:36 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 28 May 2013 21:34:36 +0100
Subject: Python #ifdef
In-Reply-To: <BLU176-W163A3FC339C409E765BA5DD7970@phx.gbl>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2318.1369770916.3114.python-list@python.org>
	<b0kgm4F3gs4U1@mid.individual.net>
	<mailman.2320.1369771667.3114.python-list@python.org>
	<ko334b$83c$1@reader1.panix.com>
	<BLU176-W163A3FC339C409E765BA5DD7970@phx.gbl>
Message-ID: <CAA=1kxS04Rtr_guJ_HWBOZMaK76capatJ4L2Xdjh0fkjGo_4Gw@mail.gmail.com>

On 28 May 2013 21:26, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
wrote:
> Haha! That's it!!!
>
> Just realized how funny this can be: ;)
>
> ### never to be opened ###
> def pandoras_box(v):
>     return v/0.0
>
> if customer_didnt_pay():
>     pandoras_box()
>
> #lol

1/0 is, after print, my most common debug statement.
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From carlosnepomuceno at outlook.com  Tue May 28 16:48:32 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 23:48:32 +0300
Subject: Python #ifdef
In-Reply-To: <CAA=1kxS04Rtr_guJ_HWBOZMaK76capatJ4L2Xdjh0fkjGo_4Gw@mail.gmail.com>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>,
	<mailman.2318.1369770916.3114.python-list@python.org>,
	<b0kgm4F3gs4U1@mid.individual.net>,
	<mailman.2320.1369771667.3114.python-list@python.org>,
	<ko334b$83c$1@reader1.panix.com>,
	<BLU176-W163A3FC339C409E765BA5DD7970@phx.gbl>,
	<CAA=1kxS04Rtr_guJ_HWBOZMaK76capatJ4L2Xdjh0fkjGo_4Gw@mail.gmail.com>
Message-ID: <BLU176-W31553A9641A2CD141B167D7970@phx.gbl>

________________________________
> Date: Tue, 28 May 2013 21:34:36 +0100 
> Subject: RE: Python #ifdef 
> From: fabiosantosart at gmail.com 
> To: carlosnepomuceno at outlook.com 
> CC: python-list at python.org 
>  
>  
> On 28 May 2013 21:26, "Carlos Nepomuceno"  
> <carlosnepomuceno at outlook.com<mailto:carlosnepomuceno at outlook.com>>  
> wrote: 
> > Haha! That's it!!! 
> > 
> > Just realized how funny this can be: ;) 
> > 
> > ### never to be opened ### 
> > def pandoras_box(v): 
> >     return v/0.0 
> > 
> > if customer_didnt_pay(): 
> >     pandoras_box() 
> > 
> > #lol 
>  
> 1/0 is, after print, my most common debug statement.

What's the best debugger for Python? Have you tried HAP[1]?

[1] http://hapdebugger.sourceforge.net/ 		 	   		  

From fabiosantosart at gmail.com  Tue May 28 18:51:08 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Tue, 28 May 2013 23:51:08 +0100
Subject: Python #ifdef
In-Reply-To: <BLU176-W31553A9641A2CD141B167D7970@phx.gbl>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2318.1369770916.3114.python-list@python.org>
	<b0kgm4F3gs4U1@mid.individual.net>
	<mailman.2320.1369771667.3114.python-list@python.org>
	<ko334b$83c$1@reader1.panix.com>
	<BLU176-W163A3FC339C409E765BA5DD7970@phx.gbl>
	<CAA=1kxS04Rtr_guJ_HWBOZMaK76capatJ4L2Xdjh0fkjGo_4Gw@mail.gmail.com>
	<BLU176-W31553A9641A2CD141B167D7970@phx.gbl>
Message-ID: <CAA=1kxQEatWDvLwwjQZ=-E=TRQF-FvGR2O70Vy3WnWoyaACygQ@mail.gmail.com>

On 28 May 2013 21:53, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
wrote:
>
> ________________________________
> > Date: Tue, 28 May 2013 21:34:36 +0100
> > Subject: RE: Python #ifdef
> > From: fabiosantosart at gmail.com
> > To: carlosnepomuceno at outlook.com
> > CC: python-list at python.org
> >
> >
> > On 28 May 2013 21:26, "Carlos Nepomuceno"
> > <carlosnepomuceno at outlook.com<mailto:carlosnepomuceno at outlook.com>>
> > wrote:
> > > Haha! That's it!!!
> > >
> > > Just realized how funny this can be: ;)
> > >
> > > ### never to be opened ###
> > > def pandoras_box(v):
> > >     return v/0.0
> > >
> > > if customer_didnt_pay():
> > >     pandoras_box()
> > >
> > > #lol
> >
> > 1/0 is, after print, my most common debug statement.
>
> What's the best debugger for Python? Have you tried HAP[1]?
>
> [1] http://hapdebugger.sourceforge.net/

Never saw that, but the remote debugging looks like it adds some
flexibility. That said, I don't often use a debugger. When I do, it's pdb.
Pdb is not bad at all, and it comes in the stdlib, which makes it readily
available in a virtualenv. It's impractical to set more than a breakpoint,
but then again I only use a breakpoint at a time.
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From invalid at invalid.invalid  Tue May 28 16:42:34 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Tue, 28 May 2013 20:42:34 +0000 (UTC)
Subject: Python #ifdef
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2318.1369770916.3114.python-list@python.org>
	<b0kgm4F3gs4U1@mid.individual.net>
	<mailman.2320.1369771667.3114.python-list@python.org>
	<ko334b$83c$1@reader1.panix.com>
	<mailman.2322.1369772569.3114.python-list@python.org>
Message-ID: <ko34rq$m2s$1@reader1.panix.com>

On 2013-05-28, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:

> [...]
>> You're trying to make this a lot harder than it really is:
>>
>> if sys.version_info[0] == 3:
>> def original(n):
>> m = 0
>> for b in n.to_bytes(6, 'big'):
>> m = 256*m + b
>> return m
>> else:
>> def original(n):
>> <something else?>
>
> Haha! That's it!!!
>
> Just realized how funny this can be: ;)

Here's the important lesson from this thread:

Instead of asking "how do I write X in Python" where yoy've assumed X
is the solution to your problem, you're usually better off asking how
to solve the underlying problem in a Pythonic way.

IOW, instead of asking about a Python preprocessor (which you have
assumed is the solution to the problem because that's how you would do
it in C), ask about the actual problem (how to define a function
differently depending on Python version).

People on this list are very inventive and will expend a surprising
amount of time to figure out often too-clever ways to do X because you
asked how to do X -- even if doing X is a lousy way to solve your
actual problem...

When asking how do I solve a problem, it's OK to illustrate that
question with an example X of how you would solve it in C or Java or
Ruby or Perl or whatever, but remember

  1) Not everybody here knows C or Java or Ruby or Perl or whatever,
     and the person who _does_ know everyting there is to know about
     solving some particular underlying problem isn't going to go
     learn a new language so that they can understand your example and
     figure out what you're trying to accomplish.

  2) Programming languages differ. X may be the best way to solve the
     problem in one language, but it might be an awful way to do it in
     another language.

-- 
Grant Edwards               grant.b.edwards        Yow! I'm ANN LANDERS!!
                                  at               I can SHOPLIFT!!
                              gmail.com            


From carlosnepomuceno at outlook.com  Tue May 28 16:54:46 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Tue, 28 May 2013 23:54:46 +0300
Subject: Python #ifdef
In-Reply-To: <ko34rq$m2s$1@reader1.panix.com>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>,
	<mailman.2318.1369770916.3114.python-list@python.org>,
	<b0kgm4F3gs4U1@mid.individual.net>,
	<mailman.2320.1369771667.3114.python-list@python.org>,
	<ko334b$83c$1@reader1.panix.com>,
	<mailman.2322.1369772569.3114.python-list@python.org>,
	<ko34rq$m2s$1@reader1.panix.com>
Message-ID: <BLU176-W277649029AA72F62A488CDD7970@phx.gbl>

----------------------------------------
> From: invalid at invalid.invalid
> Subject: Re: Python #ifdef
> Date: Tue, 28 May 2013 20:42:34 +0000
> To: python-list at python.org
[...]
> Here's the important lesson from this thread:
>
> Instead of asking "how do I write X in Python" where yoy've assumed X
> is the solution to your problem, you're usually better off asking how
> to solve the underlying problem in a Pythonic way.
>
> IOW, instead of asking about a Python preprocessor (which you have
> assumed is the solution to the problem because that's how you would do
> it in C), ask about the actual problem (how to define a function
> differently depending on Python version).
>
> People on this list are very inventive and will expend a surprising
> amount of time to figure out often too-clever ways to do X because you
> asked how to do X -- even if doing X is a lousy way to solve your
> actual problem...
>
> When asking how do I solve a problem, it's OK to illustrate that
> question with an example X of how you would solve it in C or Java or
> Ruby or Perl or whatever, but remember
>
> 1) Not everybody here knows C or Java or Ruby or Perl or whatever,
> and the person who _does_ know everyting there is to know about
> solving some particular underlying problem isn't going to go
> learn a new language so that they can understand your example and
> figure out what you're trying to accomplish.
>
> 2) Programming languages differ. X may be the best way to solve the
> problem in one language, but it might be an awful way to do it in
> another language.
>
> --
> Grant Edwards grant.b.edwards Yow! I'm ANN LANDERS!!
> at I can SHOPLIFT!!
> gmail.com


You're right! Sometimes I hate myself for doing exactly the opposite of what I would like to do!

Unfortunately I can't change the thread subject.

How do you have "invalid at invalid.invalid" instead of your email address? 		 	   		  

From invalid at invalid.invalid  Wed May 29 10:45:37 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 29 May 2013 14:45:37 +0000 (UTC)
Subject: Python #ifdef
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2318.1369770916.3114.python-list@python.org>
	<b0kgm4F3gs4U1@mid.individual.net>
	<mailman.2320.1369771667.3114.python-list@python.org>
	<ko334b$83c$1@reader1.panix.com>
	<mailman.2322.1369772569.3114.python-list@python.org>
	<ko34rq$m2s$1@reader1.panix.com>
	<mailman.2326.1369774488.3114.python-list@python.org>
Message-ID: <ko54ah$c5b$1@reader1.panix.com>

On 2013-05-28, Carlos Nepomuceno <carlosnepomuceno at outlook.com> wrote:

> How do you have "invalid at invalid.invalid" instead of your email address?

I have this in my .slrnrc:

 set hostname "invalid.invalid"
 set username "grant"
 set realname "Grant Edwards"

I'm not sure why it doesn't show up as grant at invalid.invalid -- I
think it used to.

Since I'm this as a Usenet news group using the slrn newsreader
program, there's no need to make my email address visible in the
message headers in a usable form.  I originally did this long ago
(probably 20 years) to avoid spam.  I'm pretty sure that it's all in
vain these days, and the spam filters at Google are what's keeping me
from drowning.

-- 
Grant Edwards               grant.b.edwards        Yow! Gee, I feel kind of
                                  at               LIGHT in the head now,
                              gmail.com            knowing I can't make my
                                                   satellite dish PAYMENTS!


From breamoreboy at yahoo.co.uk  Tue May 28 18:18:34 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 28 May 2013 23:18:34 +0100
Subject: Python #ifdef
In-Reply-To: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
Message-ID: <ko3af7$ar9$1@ger.gmane.org>

On 28/05/2013 20:46, Carlos Nepomuceno wrote:
> Are there Python 'preprocessor directives'?
>
> I'd like to have something like '#ifdef' to mix code from Python 2 and 3 in a single file.
>
> Is that possible? How? 		 	   		
>

https://pypi.python.org/pypi/six/1.3.0

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From joel.goldstick at gmail.com  Tue May 28 18:25:59 2013
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Tue, 28 May 2013 18:25:59 -0400
Subject: Python #ifdef
In-Reply-To: <ko3af7$ar9$1@ger.gmane.org>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<ko3af7$ar9$1@ger.gmane.org>
Message-ID: <CAPM-O+wBX54-K-U=Nkd8rirc3YOMTHcnEfkZAnm=76MdSQ7-gQ@mail.gmail.com>

On Tue, May 28, 2013 at 6:18 PM, Mark Lawrence <breamoreboy at yahoo.co.uk>wrote:

> On 28/05/2013 20:46, Carlos Nepomuceno wrote:
>
>> Are there Python 'preprocessor directives'?
>>
>> I'd like to have something like '#ifdef' to mix code from Python 2 and 3
>> in a single file.
>>
>> Is that possible? How?
>>
>>
> https://pypi.python.org/pypi/**six/1.3.0<https://pypi.python.org/pypi/six/1.3.0>
>
> --
> If you're using GoogleCrap? please read this http://wiki.python.org/moin/*
> *GoogleGroupsPython <http://wiki.python.org/moin/GoogleGroupsPython>.
>
> Mark Lawrence
>
> --
> http://mail.python.org/**mailman/listinfo/python-list<http://mail.python.org/mailman/listinfo/python-list>
>

my original response was from cell phone.  I just answered that you can't
do ifdefs, implying that there is no preprocessor in python.  I learned a
lot of things I didn't know reading the thread, but I wonder if it is a
good idea in general to try to write code like this.  -- combined 2.x/3.x
codebase can be a bear to maintain.  I wouldn't do it unless there was some
imposing reason that I must.  Its not just print() -- that isn't bad, but
changes in module names (urllib), arithmetic, and unicode especially make
this idea in general, very tricky.  Pity the next developer who needs to
try to maintain it.

So, maybe you CAN do it, but SHOULD you want to do it?

-- 
Joel Goldstick
http://joelgoldstick.com
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From carlosnepomuceno at outlook.com  Tue May 28 18:50:35 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Wed, 29 May 2013 01:50:35 +0300
Subject: Python #ifdef
In-Reply-To: <CAPM-O+wBX54-K-U=Nkd8rirc3YOMTHcnEfkZAnm=76MdSQ7-gQ@mail.gmail.com>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>,
	<ko3af7$ar9$1@ger.gmane.org>,
	<CAPM-O+wBX54-K-U=Nkd8rirc3YOMTHcnEfkZAnm=76MdSQ7-gQ@mail.gmail.com>
Message-ID: <BLU176-W250E9022F2F1F8CBFB667BD7970@phx.gbl>

________________________________
> Date: Tue, 28 May 2013 18:25:59 -0400 
> Subject: Re: Python #ifdef 
> From: joel.goldstick at gmail.com 
> To: breamoreboy at yahoo.co.uk 
> CC: python-list at python.org 
[...]
>  
> my original response was from cell phone.  I just answered that you  
> can't do ifdefs, implying that there is no preprocessor in python.  I  
> learned a lot of things I didn't know reading the thread, but I wonder  
> if it is a good idea in general to try to write code like this.  --  
> combined 2.x/3.x codebase can be a bear to maintain.  I wouldn't do it  
> unless there was some imposing reason that I must.  Its not just  
> print() -- that isn't bad, but changes in module names (urllib),  
> arithmetic, and unicode especially make this idea in general, very  
> tricky.  Pity the next developer who needs to try to maintain it. 
>  
> So, maybe you CAN do it, but SHOULD you want to do it? 
>  
> --  
> Joel Goldstick 
> http://joelgoldstick.com 


Thanks Joel! In this case I think it does because I would like to have the same short benchmarking script to be runnable by Python 2 and Python 3.

The only piece of code that doesn't run on Python 2 is a to_bytes() single call. So it's not a huge maintenance load. ;)

I didn't try to write 'portable' code to Python 3 yet. What's the catch? 		 	   		  

From tjreedy at udel.edu  Tue May 28 20:31:39 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Tue, 28 May 2013 20:31:39 -0400
Subject: Python #ifdef
In-Reply-To: <CAPM-O+wBX54-K-U=Nkd8rirc3YOMTHcnEfkZAnm=76MdSQ7-gQ@mail.gmail.com>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<ko3af7$ar9$1@ger.gmane.org>
	<CAPM-O+wBX54-K-U=Nkd8rirc3YOMTHcnEfkZAnm=76MdSQ7-gQ@mail.gmail.com>
Message-ID: <ko3i8r$992$1@ger.gmane.org>

On 5/28/2013 6:25 PM, Joel Goldstick wrote:
> On Tue, May 28, 2013 at 6:18 PM, Mark Lawrence <breamoreboy at yahoo.co.uk
> <mailto:breamoreboy at yahoo.co.uk>> wrote:

>     On 28/05/2013 20:46, Carlos Nepomuceno wrote:
>         I'd like to have something like '#ifdef' to mix code from Python
>         2 and 3 in a single file.

>     https://pypi.python.org/pypi/__six/1.3.0
>     <https://pypi.python.org/pypi/six/1.3.0>

> my original response was from cell phone.  I just answered that you
> can't do ifdefs, implying that there is no preprocessor in python.  I
> learned a lot of things I didn't know reading the thread, but I wonder
> if it is a good idea in general to try to write code like this.  --
> combined 2.x/3.x codebase can be a bear to maintain.

Many people have come to prefer a) a single 2&3 codebase over b) 
separate 2 and 3 codebases or c) a single 2 codebase repeatedly 
converted to a 3 codebase with 2to3.

They use 2to3 once (well, a few times) to discover differences that need 
to be considered.

For 2.7 and 3.x, the future imports are enough for some code. The six 
module handles harder cases.

> I wouldn't do it
> unless there was some imposing reason that I must.  Its not just print()
> -- that isn't bad, but changes in module names (urllib),

I believe six handles that

 > arithmetic, and

from __future__ import integer_division  # spelling?
handles the only change

> unicode

Use unicode consistently and
from __future__ import unicode_literals  # spelling?
or the re-addition u'' prefix do quite well.

Otherwise, do not use things that evaporated, like apply() and classic 
classes. (Inherit from object if nothing else.)

This is all hearsay coming from me ;-).

Terry




From steve+comp.lang.python at pearwood.info  Tue May 28 20:57:10 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 29 May 2013 00:57:10 GMT
Subject: Supporting both 2.x and 3.x in one code base [was Re: Python #ifdef]
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<ko3af7$ar9$1@ger.gmane.org>
	<mailman.2330.1369779961.3114.python-list@python.org>
Message-ID: <51a55265$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Tue, 28 May 2013 18:25:59 -0400, Joel Goldstick wrote:

> I wonder
> if it is a good idea in general to try to write code like this.  --
> combined 2.x/3.x codebase can be a bear to maintain.

Not so much a bear as a tiny little kitten.


> I wouldn't do it
> unless there was some imposing reason that I must.  Its not just print()
> -- that isn't bad, but changes in module names (urllib), arithmetic, and
> unicode especially make this idea in general, very tricky.  Pity the
> next developer who needs to try to maintain it.

It's not that hard really. Well, like all things, it depends on the 
circumstances. If you're reliant on external modules, you *may* have a 
bad time if those modules are 2.x only or 3.x only, but the standard 
library and built-ins don't provide too much of a challenge.

There's no doubt that supporting 2.x and 3.x in one code base is more 
difficult that just supporting one or the other, but the difficulty is 
much less than often supposed. Python 2.7, and to a lesser extent, 2.6, 
are designed to be as easy to port to 3.x as possible, which has the 
happy side-effect that they are also relatively easy to write code for 
them that will also run under 3.x.

Many of the differences can be eliminated with a few __future__ imports:

from __future__ import division, print_function


Differences in behaviour of the built-ins can be eliminated:

from future_builtins import *


Built-ins such as reduce and cmp that have been moved, or eliminated, can 
easily be restored:

if sys.version >= '3':
    from functools import reduce


Or if you prefer a "Better To Ask Forgiveness Than Permission" approach:

try:
    reduce
except NameError:
    from functools import reduce


Name changes of modules are easy to deal with:

try:
    import configparser
except ImportError:
    import ConfigParser as configparser


The most difficult difference is the difference between strings in 2.x 
and 3.x, but if you drop support for Python 3.1 and 3.2, you can write 
code that works in both 2.7 and 3.3 by using the u"" syntax. Or just use 
ASCII literals, which work perfectly in both.

There are really only a very few things that cannot be shared between 2.x 
and 3.x: syntactical features that are only supported by 3.x. So if 
you're planning on writing code that runs in both 2.x and 3.x, you need 
to eschew the 3-only features like keyword-only function arguments and 
function annotations.

But that's no different than writing code to support *any* two versions 
that don't have identical syntax. E.g. 2.4 and 2.5: 2.5 supports ternary 
if, `a if condition else b`, while 2.4 does not, so if you need to 
support both, you can't use ternary if. Nearly all the code I write is 
for 2.4 or better, and I can assure you that the hardest part is 
supporting 2.4. Adding 3.x doesn't make it much harder.

(My hat goes off to those supporting 2.3 through 3.3 in one code base. 
That is, frankly, astonishing.)

Nobody *likes* to have to support really old versions missing the cool 
syntax that you want to use, but nobody says that you should even try. 
3.x doesn't change that.



-- 
Steven


From dihedral88888 at gmail.com  Tue May 28 19:04:25 2013
From: dihedral88888 at gmail.com (88888 Dihedral)
Date: Tue, 28 May 2013 16:04:25 -0700 (PDT)
Subject: Python #ifdef
In-Reply-To: <mailman.2317.1369770400.3114.python-list@python.org>
References: <mailman.2317.1369770400.3114.python-list@python.org>
Message-ID: <aabfb355-7210-44a5-9576-357bc82abb47@googlegroups.com>

Carlos Nepomuceno? 2013?5?29????UTC+8??3?46?37????
> Are there Python 'preprocessor directives'?
> 
> I'd like to have something like '#ifdef' to mix code from Python 2 and 3 in a single file.
> 
> Is that possible? How?

Use execfile(filename) at the beginning to get what you want.
The .pyc version is preferred.


From drsalists at gmail.com  Tue May 28 21:23:33 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Tue, 28 May 2013 18:23:33 -0700
Subject: Python #ifdef
In-Reply-To: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
Message-ID: <CAGGBd_qOZpb102J1ZznNN7tz+T4XUy5Co+21kmFJvHZDR5bXig@mail.gmail.com>

Here're slides from a presentation about writing code that runs on 2.x and
3.x: http://stromberg.dnsalias.org/~dstromberg/Intro-to-Python/

And in case you still want a preprocessor for Python (you likely don't need
one this time), here's an example of doing this using the venerable m4:
https://pypi.python.org/pypi/red-black-tree-mod .  Note the many comments
added to keep line numbers consistent.

Sent from my android phone.
On May 28, 2013 12:47 PM, "Carlos Nepomuceno" <carlosnepomuceno at outlook.com>
wrote:

> Are there Python 'preprocessor directives'?
>
> I'd like to have something like '#ifdef' to mix code from Python 2 and 3
> in a single file.
>
> Is that possible? How?
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From invalid at invalid.invalid  Wed May 29 10:55:18 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 29 May 2013 14:55:18 +0000 (UTC)
Subject: Python #ifdef
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2336.1369790616.3114.python-list@python.org>
Message-ID: <ko54sm$c5b$2@reader1.panix.com>

On 2013-05-29, Dan Stromberg <drsalists at gmail.com> wrote:

> And in case you still want a preprocessor for Python (you likely don't need
> one this time), here's an example of doing this using the venerable m4:
> https://pypi.python.org/pypi/red-black-tree-mod .  Note the many comments
> added to keep line numbers consistent.

I was wondering whether or not to mention m4.  Since m4 is (in my
mind) inextricably linked to RATFOR and sendmail config files I try
to avoid thinking about it lest the flashbacks start again...

-- 
Grant Edwards               grant.b.edwards        Yow! Hmmm ... a CRIPPLED
                                  at               ACCOUNTANT with a FALAFEL
                              gmail.com            sandwich is HIT by a
                                                   TROLLEY-CAR ...


From rosuav at gmail.com  Wed May 29 11:05:35 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 01:05:35 +1000
Subject: Python #ifdef
In-Reply-To: <ko54sm$c5b$2@reader1.panix.com>
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2336.1369790616.3114.python-list@python.org>
	<ko54sm$c5b$2@reader1.panix.com>
Message-ID: <CAPTjJmo=jLq4bX=JLJAjhutkxVaohfD30i7Ya9NQVVhK+re22A@mail.gmail.com>

On Thu, May 30, 2013 at 12:55 AM, Grant Edwards <invalid at invalid.invalid> wrote:
> On 2013-05-29, Dan Stromberg <drsalists at gmail.com> wrote:
>
>> And in case you still want a preprocessor for Python (you likely don't need
>> one this time), here's an example of doing this using the venerable m4:
>> https://pypi.python.org/pypi/red-black-tree-mod .  Note the many comments
>> added to keep line numbers consistent.
>
> I was wondering whether or not to mention m4.  Since m4 is (in my
> mind) inextricably linked to RATFOR and sendmail config files I try
> to avoid thinking about it lest the flashbacks start again...

It's not a bad tool. I used it as a sort of PHP preprocessor, because
requirements at work had me wanting to have a source file defining a
PHP class and having an autogenerated section in the middle of that
class. PHP's 'include' directive doesn't work for that. Of course, had
we been using a better language, that wouldn't have been an issue (and
it stopped being an issue when we improved the design and stopped
using that class system, too, though I retained the makefile
directives about building .php.m4 -> .php files). But still, GNU M4 is
a decent piece of technology.

ChrisA


From invalid at invalid.invalid  Wed May 29 11:25:56 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 29 May 2013 15:25:56 +0000 (UTC)
Subject: Python #ifdef
References: <BLU176-W12FAFEA3C7AFD687855E04D7970@phx.gbl>
	<mailman.2336.1369790616.3114.python-list@python.org>
	<ko54sm$c5b$2@reader1.panix.com>
	<mailman.2361.1369839938.3114.python-list@python.org>
Message-ID: <ko56m4$e4j$1@reader1.panix.com>

On 2013-05-29, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, May 30, 2013 at 12:55 AM, Grant Edwards <invalid at invalid.invalid> wrote:
>> On 2013-05-29, Dan Stromberg <drsalists at gmail.com> wrote:
>>
>>> And in case you still want a preprocessor for Python (you likely don't need
>>> one this time), here's an example of doing this using the venerable m4:
>>> https://pypi.python.org/pypi/red-black-tree-mod .  Note the many comments
>>> added to keep line numbers consistent.
>>
>> I was wondering whether or not to mention m4.  Since m4 is (in my
>> mind) inextricably linked to RATFOR and sendmail config files I try
>> to avoid thinking about it lest the flashbacks start again...
>
> It's not a bad tool. I used it as a sort of PHP preprocessor, 
> [...]
> But still, GNU M4 is a decent piece of technology.

I didn't mean to disparage m4 -- it always seemed well thought out and
useful.  It just happens to be associated with unpleasant things for
me.  [And it didn't really seem like a good option for the OP's
problem.]

Still, if one really did want a preprocessor for Python programs, m4
would be the first thing I'd look at.

-- 
Grant Edwards               grant.b.edwards        Yow! I wonder if I ought
                                  at               to tell them about my
                              gmail.com            PREVIOUS LIFE as a COMPLETE
                                                   STRANGER?


From fabiofz at gmail.com  Tue May 28 16:28:31 2013
From: fabiofz at gmail.com (Fabio Zadrozny)
Date: Tue, 28 May 2013 17:28:31 -0300
Subject: PyDev 2.7.5 Released
Message-ID: <CANXBEFofDo39Qi68T+MuQ9EWCzvcQYx7nHx-UEjGGr-cU5o0XQ@mail.gmail.com>

Hi All,

PyDev 2.7.5 has been released

Details on PyDev: http://pydev.org
Details on its development: http://pydev.blogspot.com

Release Highlights:
-------------------------------

* Icons in the outline are now correct.

* Fixed deadlock found on code analysis.

* Project-related error markers no longer created in the main thread.

* Showing a dialog to select template when a new module is created.

* PyUnit view output font uses the same font as the console

* New option in auto-formatting to auto-format only workspace files.

* Auto-formatting with only deleted lines no longer changes everything.

* PyUnit view orientation menu is now properly shown.

* Fixed interaction with external files on pydev package explorer.

What is PyDev?
---------------------------

PyDev is a plugin that enables users to use Eclipse for Python, Jython and
IronPython development -- making Eclipse a first class Python IDE -- It
comes with many goodies such as code completion, syntax highlighting,
syntax analysis, refactor, debug and many others.


Cheers,

-- 
Fabio Zadrozny
------------------------------------------------------
Software Developer

PyDev - Python Development Environment for Eclipse
http://pydev.org
http://pydev.blogspot.com
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From ralf at systemexit.de  Tue May 28 19:32:41 2013
From: ralf at systemexit.de (Ralf Schmitt)
Date: Wed, 29 May 2013 01:32:41 +0200
Subject: [ANN] pypiserver 1.1.1 - minimal private pypi server
Message-ID: <87ip227k9y.fsf@myhost.lan>

Hi,

I've just uploaded pypiserver 1.1.1 to the python package index.

pypiserver is a minimal PyPI compatible server. It can be used to serve
a set of packages and eggs to easy_install or pip.

pypiserver is easy to install (i.e. just 'pip install pypiserver'). It
doesn't have any external dependencies.

https://pypi.python.org/pypi/pypiserver/ should contain enough
information to easily get you started running your own PyPI server in a
few minutes.

The code is available on github: https://github.com/schmir/pypiserver

Changes in this version
-----------------------
- add 'overwrite' option to allow overwriting existing package
  files (default: false)
- show names with hyphens instead of underscores on the "/simple"
  listing
- make the standalone version work with jython 2.5.3
- upgrade waitress to 0.8.5 in the standalone version
- workaround broken xmlrpc api on pypi.python.org by using HTTPS

-- 
Cheers
Ralf


From omrahulrajcse at gmail.com  Wed May 29 05:09:05 2013
From: omrahulrajcse at gmail.com (RAHUL RAJ)
Date: Wed, 29 May 2013 02:09:05 -0700 (PDT)
Subject: MySQL dymanic query in Python
Message-ID: <2fd0cae6-6cfe-4163-964e-2aa863e65f5e@googlegroups.com>

Can anyone tell me the proper way in which I can execute dynamic MySQL queries in Python?

I want to do dynamic queries for both CREATE and INSERT statement.

Here is my attempted code:


sql="create table %s (%%s, %%s, %%s ... )" % (tablename,''.join(fields)+' '.join(types))
cur.execute(sql)  


where 'field' is the fieldnames stored in a list and 'types' are the fieldtypes stored in a list. 



From fabiosantosart at gmail.com  Wed May 29 06:02:51 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Wed, 29 May 2013 11:02:51 +0100
Subject: MySQL dymanic query in Python
In-Reply-To: <2fd0cae6-6cfe-4163-964e-2aa863e65f5e@googlegroups.com>
References: <2fd0cae6-6cfe-4163-964e-2aa863e65f5e@googlegroups.com>
Message-ID: <CAA=1kxQmuh9c2QqNbC3LVnLBPtfRbmoQpg-u3dscDCkPeMme5A@mail.gmail.com>

On 29 May 2013 10:13, "RAHUL RAJ" <omrahulrajcse at gmail.com> wrote:
>
> Can anyone tell me the proper way in which I can execute dynamic MySQL
queries in Python?
>
> I want to do dynamic queries for both CREATE and INSERT statement.
>
> Here is my attempted code:
>
>
> sql="create table %s (%%s, %%s, %%s ... )" % (tablename,''.join(fields)+'
'.join(types))
> cur.execute(sql)
>
>
> where 'field' is the fieldnames stored in a list and 'types' are the
fieldtypes stored in a list.

You need to join the fields and the field types. Use zip().

Then join with commas.

fields_and_types = ['%s %s' % (field, type) for field, type in zip(fields,
types)]

what_goes_between_the_parens = ', '.join(fields_and_types)

sql = 'create table %s (%s)' % (tablename, what_goes_between_the_parens)

See where that gets you.
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From omrahulrajcse at gmail.com  Thu May 30 08:22:52 2013
From: omrahulrajcse at gmail.com (RAHUL RAJ)
Date: Thu, 30 May 2013 05:22:52 -0700 (PDT)
Subject: MySQL dymanic query in Python
In-Reply-To: <mailman.2345.1369821775.3114.python-list@python.org>
References: <2fd0cae6-6cfe-4163-964e-2aa863e65f5e@googlegroups.com>
	<mailman.2345.1369821775.3114.python-list@python.org>
Message-ID: <9f07fb7a-4d37-47cb-be22-67245dd73d1f@googlegroups.com>

On Wednesday, May 29, 2013 3:32:51 PM UTC+5:30, F?bio Santos wrote:
> On 29 May 2013 10:13, "RAHUL RAJ" <omrahu... at gmail.com> wrote:
> 
> >
> 
> > Can anyone tell me the proper way in which I can execute dynamic MySQL queries in Python?
> 
> >
> 
> > I want to do dynamic queries for both CREATE and INSERT statement.
> 
> >
> 
> > Here is my attempted code:
> 
> >
> 
> >
> 
> > sql="create table %s (%%s, %%s, %%s ... )" % (tablename,''.join(fields)+' '.join(types))
> 
> > cur.execute(sql)
> 
> >
> 
> >
> 
> > where 'field' is the fieldnames stored in a list and 'types' are the fieldtypes stored in a list.
> 
> You need to join the fields and the field types. Use zip().
> 
> Then join with commas.
> 
> fields_and_types = ['%s %s' % (field, type) for field, type in zip(fields, types)]
> 
> what_goes_between_the_parens = ', '.join(fields_and_types)
> 
> sql = 'create table %s (%s)' % (tablename, what_goes_between_the_parens)
> 
> See where that gets you.

Fantastic! It worked, Thanks :)


From jabba.laci at gmail.com  Wed May 29 07:16:59 2013
From: jabba.laci at gmail.com (Jabba Laci)
Date: Wed, 29 May 2013 13:16:59 +0200
Subject: detect key conflict in a JSON file
Message-ID: <CAOuJsMn38V2Gw3s=KMLJ+t4uFyu3GdzYyA-_TNiEqn7hWxNEjA@mail.gmail.com>

Hi,

How can you detect if a key is duplicated in a JSON file? Example:

{
    "something": [...],
    ...
    "something": [...]
}

I have a growing JSON file that I edit manually and it might happen
that I repeat a key. If this happens, I would like to get notified.
Currently the value of the second key silently overwrites the value of
the first.

Do you know about a command line JSON validator?

Thanks,

Laszlo


From roy at panix.com  Wed May 29 09:25:39 2013
From: roy at panix.com (Roy Smith)
Date: Wed, 29 May 2013 09:25:39 -0400
Subject: detect key conflict in a JSON file
References: <mailman.2347.1369826248.3114.python-list@python.org>
Message-ID: <roy-5C9415.09253929052013@news.panix.com>

In article <mailman.2347.1369826248.3114.python-list at python.org>,
 Jabba Laci <jabba.laci at gmail.com> wrote:
 
> I have a growing JSON file that I edit manually and it might happen
> that I repeat a key. If this happens, I would like to get notified.

The real answer here is that JSON is probably not the best choice for 
large files that get hand-edited.  For data that you intend to hand-edit 
a lot, YAML might be a better choice.

> Currently the value of the second key silently overwrites the value of
> the first.

Yeah, that's what I would expect.  http://www.json.org/ is mute on the 
question of what to do with duplicate keys, but I would be quite 
surprised to discover any implementation which behaved differently.

> Do you know about a command line JSON validator?

All JSON implementations validate their input.  You are assuming that 
having duplicate keys is "invalid".  I would think it falls more into 
the category of "undefined behavior".


From jabba.laci at gmail.com  Wed May 29 09:41:50 2013
From: jabba.laci at gmail.com (Jabba Laci)
Date: Wed, 29 May 2013 15:41:50 +0200
Subject: detect key conflict in a JSON file
In-Reply-To: <roy-5C9415.09253929052013@news.panix.com>
References: <mailman.2347.1369826248.3114.python-list@python.org>
	<roy-5C9415.09253929052013@news.panix.com>
Message-ID: <CAOuJsMkzEZGEK0gVDMYNk3y3PDgn7+nYxwur_U6=_kaUMKSGUw@mail.gmail.com>

> The real answer here is that JSON is probably not the best choice for
> large files that get hand-edited.  For data that you intend to hand-edit
> a lot, YAML might be a better choice.
>
>> Currently the value of the second key silently overwrites the value of
>> the first.

Thanks but how would it be different with YAML? Can YAML check duplicate keys?

How to process (read) YAML files in Python? Can you give me some hints
how to get started? All I need is read it in and create a dictionary
of it.

Thanks,

Laszlo


From airween at gmail.com  Wed May 29 10:04:00 2013
From: airween at gmail.com (Ervin =?utf-8?Q?Heged=C3=BCs?=)
Date: Wed, 29 May 2013 16:04:00 +0200
Subject: detect key conflict in a JSON file
In-Reply-To: <CAOuJsMkzEZGEK0gVDMYNk3y3PDgn7+nYxwur_U6=_kaUMKSGUw@mail.gmail.com>
References: <mailman.2347.1369826248.3114.python-list@python.org>
	<roy-5C9415.09253929052013@news.panix.com>
	<CAOuJsMkzEZGEK0gVDMYNk3y3PDgn7+nYxwur_U6=_kaUMKSGUw@mail.gmail.com>
Message-ID: <20130529140359.GA6033@arxnet.hu>

Hello,

On Wed, May 29, 2013 at 03:41:50PM +0200, Jabba Laci wrote:
> > The real answer here is that JSON is probably not the best choice for
> > large files that get hand-edited.  For data that you intend to hand-edit
> > a lot, YAML might be a better choice.
> >
> >> Currently the value of the second key silently overwrites the value of
> >> the first.
> 
> Thanks but how would it be different with YAML? Can YAML check duplicate keys?

no, I think it can't,

I'm using yaml a few months ago, as I noticed, the last key
prevail.


> How to process (read) YAML files in Python? Can you give me some hints
> how to get started? All I need is read it in and create a dictionary
> of it.


import yaml


struct = yaml.load(file("yamlfile.yml" 'r'))



and struct will be a Python dictionary,



As I know, yaml modul is not part of standard Python library, but
most Linux systems has package, eg. Debian/Ubuntu has a
"python-yaml".



Cheers:


a.



From roy at panix.com  Wed May 29 11:20:59 2013
From: roy at panix.com (Roy Smith)
Date: Wed, 29 May 2013 11:20:59 -0400
Subject: detect key conflict in a JSON file
In-Reply-To: <CAOuJsMkzEZGEK0gVDMYNk3y3PDgn7+nYxwur_U6=_kaUMKSGUw@mail.gmail.com>
References: <mailman.2347.1369826248.3114.python-list@python.org>
	<roy-5C9415.09253929052013@news.panix.com>
	<CAOuJsMkzEZGEK0gVDMYNk3y3PDgn7+nYxwur_U6=_kaUMKSGUw@mail.gmail.com>
Message-ID: <FE93A38C-F002-498A-83E2-54839D679791@panix.com>

On May 29, 2013, at 9:41 AM, Jabba Laci wrote:

>> The real answer here is that JSON is probably not the best choice for
>> large files that get hand-edited.  For data that you intend to hand-edit
>> a lot, YAML might be a better choice.
>> 
>>> Currently the value of the second key silently overwrites the value of
>>> the first.
> 
> Thanks but how would it be different with YAML? Can YAML check duplicate keys?

Oh, I didn't mean to imply that.  I was just pointing out that in general, YAML is more friendly for hand-editing than JSON.  They both have the same GIGO issue.

> How to process (read) YAML files in Python?

Take a look at http://pyyaml.org/


---
Roy Smith
roy at panix.com



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From steve+comp.lang.python at pearwood.info  Wed May 29 23:10:03 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 03:10:03 GMT
Subject: detect key conflict in a JSON file
References: <mailman.2347.1369826248.3114.python-list@python.org>
	<roy-5C9415.09253929052013@news.panix.com>
	<CAOuJsMkzEZGEK0gVDMYNk3y3PDgn7+nYxwur_U6=_kaUMKSGUw@mail.gmail.com>
	<mailman.2363.1369840867.3114.python-list@python.org>
Message-ID: <51a6c30b$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Wed, 29 May 2013 11:20:59 -0400, Roy Smith wrote:

>> How to process (read) YAML files in Python?
> 
> Take a look at http://pyyaml.org/

Beware that pyaml suffers from the same issue as pickle, namely that it 
can execute arbitrary code when reading untrusted data.


-- 
Steven


From rustompmody at gmail.com  Wed May 29 10:36:02 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 29 May 2013 07:36:02 -0700 (PDT)
Subject: detect key conflict in a JSON file
References: <mailman.2347.1369826248.3114.python-list@python.org>
	<roy-5C9415.09253929052013@news.panix.com>
	<mailman.2357.1369834941.3114.python-list@python.org>
Message-ID: <3ec122c1-2968-4fe4-859c-2f7a5a089958@vy4g2000pbc.googlegroups.com>

On May 29, 6:41?pm, Jabba Laci <jabba.l... at gmail.com> wrote:
> > The real answer here is that JSON is probably not the best choice for
> > large files that get hand-edited. ?For data that you intend to hand-edit
> > a lot, YAML might be a better choice.
>
> >> Currently the value of the second key silently overwrites the value of
> >> the first.
>
> Thanks but how would it be different with YAML? Can YAML check duplicate keys?
>
> How to process (read) YAML files in Python? Can you give me some hints
> how to get started? All I need is read it in and create a dictionary
> of it.
>
> Thanks,
>
> Laszlo

There seems to be a suggested patch for duplicate-detection here
http://pyyaml.org/ticket/128


From clp2 at rebertia.com  Wed May 29 13:10:26 2013
From: clp2 at rebertia.com (Chris Rebert)
Date: Wed, 29 May 2013 10:10:26 -0700
Subject: detect key conflict in a JSON file
In-Reply-To: <CAOuJsMn38V2Gw3s=KMLJ+t4uFyu3GdzYyA-_TNiEqn7hWxNEjA@mail.gmail.com>
References: <CAOuJsMn38V2Gw3s=KMLJ+t4uFyu3GdzYyA-_TNiEqn7hWxNEjA@mail.gmail.com>
Message-ID: <CAMZYqRT0F6i72Wozw8q3vfgi4xo7-ZtUEMJ6Q=9=ypRGvH_vQw@mail.gmail.com>

On Wed, May 29, 2013 at 4:16 AM, Jabba Laci <jabba.laci at gmail.com> wrote:
> Hi,
>
> How can you detect if a key is duplicated in a JSON file? Example:
>
> {
>     "something": [...],
>     ...
>     "something": [...]
> }
>
> I have a growing JSON file that I edit manually and it might happen
> that I repeat a key. If this happens, I would like to get notified.
> Currently the value of the second key silently overwrites the value of
> the first.

You can pass an appropriate object_pairs_hook function to json.load():
http://docs.python.org/2/library/json.html#repeated-names-within-an-object
http://docs.python.org/2/library/json.html#json.load

Cheers,
Chris


From malaclypse2 at gmail.com  Wed May 29 23:43:18 2013
From: malaclypse2 at gmail.com (Jerry Hill)
Date: Wed, 29 May 2013 23:43:18 -0400
Subject: detect key conflict in a JSON file
In-Reply-To: <CAMZYqRT0F6i72Wozw8q3vfgi4xo7-ZtUEMJ6Q=9=ypRGvH_vQw@mail.gmail.com>
References: <CAOuJsMn38V2Gw3s=KMLJ+t4uFyu3GdzYyA-_TNiEqn7hWxNEjA@mail.gmail.com>
	<CAMZYqRT0F6i72Wozw8q3vfgi4xo7-ZtUEMJ6Q=9=ypRGvH_vQw@mail.gmail.com>
Message-ID: <CADwdpybODrhTL7hVj+3r+EZ40XteWQRxs9QxsYHkoC+DgNPNxA@mail.gmail.com>

On Wed, May 29, 2013 at 1:10 PM, Chris Rebert <clp2 at rebertia.com> wrote:

> On Wed, May 29, 2013 at 4:16 AM, Jabba Laci <jabba.laci at gmail.com> wrote:
> > I have a growing JSON file that I edit manually and it might happen
> > that I repeat a key. If this happens, I would like to get notified.
> > Currently the value of the second key silently overwrites the value of
> > the first.
>
> You can pass an appropriate object_pairs_hook function to json.load():
> http://docs.python.org/2/library/json.html#repeated-names-within-an-object
> http://docs.python.org/2/library/json.html#json.load
>

?That makes it pretty easy to provide any validation you might like to your
JSON data. Here's a quick example that raises ValueError on duplicate keys,
since the docs didn't have any examples.

Python 3.2.2 (default, Sep  4 2011, 09:51:08) [MSC v.1500 32 bit (Intel)]
on win32

?>>> s = '{"x": 1, "x": 2, "x": 3}'
>>> def json_checker(seq):
    d = {}
    for key, value in seq:
        if key in d:
            raise ValueError("Duplicate key %r in json document" % key)
        else:
            d[key]=value
    return d

>>> json.loads(s, object_pairs_hook=json_checker)
Traceback (most recent call last):
  File "<pyshell#31>", line 1, in <module>
    json.loads(s, object_pairs_hook=checker)
  File "C:\Python32\lib\json\__init__.py", line 320, in loads
    return cls(**kw).decode(s)
  File "C:\Python32\lib\json\decoder.py", line 351, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "C:\Python32\lib\json\decoder.py", line 367, in raw_decode
    obj, end = self.scan_once(s, idx)
  File "<pyshell#30>", line 5, in json_checker
    raise ValueError("Duplicate key %r in json document" % key)
ValueError: Duplicate key 'x' in json document

--
?
Jerry?
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From avnesh.nitk at gmail.com  Wed May 29 07:14:57 2013
From: avnesh.nitk at gmail.com (Avnesh Shakya)
Date: Wed, 29 May 2013 04:14:57 -0700 (PDT)
Subject: Output is not coming with defined color
Message-ID: <0965b949-8bf4-4105-aa8a-17cfd0d22aa4@googlegroups.com>

hi,
   I am trying to display my output with different colour on terminal, but it's
coming with that colour code.
Please help me how is it possible?

my code is - 
from fabric.colors import green, red, blue
def colorr():
    a = red('This is red')
    b = green('This is green')
    c = blue('This is blue')
    d = {a, b, c}
    print d
colorr()

output - 
set(['\x1b[32mThis is green\x1b[0m', '\x1b[34mThis is blue\x1b[0m', '\x1b[31mThis is red\x1b[0m'])

Thanks


From fabiosantosart at gmail.com  Wed May 29 08:11:17 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Wed, 29 May 2013 13:11:17 +0100
Subject: Output is not coming with defined color
In-Reply-To: <0965b949-8bf4-4105-aa8a-17cfd0d22aa4@googlegroups.com>
References: <0965b949-8bf4-4105-aa8a-17cfd0d22aa4@googlegroups.com>
Message-ID: <CAA=1kxR5C+sPcA5Hf54bohM20e8GMVK3jfhi_dmS9oBTapuneA@mail.gmail.com>

On 29 May 2013 12:25, "Avnesh Shakya" <avnesh.nitk at gmail.com> wrote:
>
> hi,
>    I am trying to display my output with different colour on terminal,
but it's
> coming with that colour code.
> Please help me how is it possible?
>
> my code is -
> from fabric.colors import green, red, blue
> def colorr():
>     a = red('This is red')
>     b = green('This is green')
>     c = blue('This is blue')
>     d = {a, b, c}
>     print d
> colorr()
>
> output -
> set(['\x1b[32mThis is green\x1b[0m', '\x1b[34mThis is blue\x1b[0m',
'\x1b[31mThis is red\x1b[0m'])
>
> Thanks

You are printing the {a, b, c} set. That ends up printing the repr of all
of its contents. The repr breaks the desired output. Try to just

print a, b, c
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From rustompmody at gmail.com  Wed May 29 10:09:44 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 29 May 2013 07:09:44 -0700 (PDT)
Subject: Output is not coming with defined color
References: <0965b949-8bf4-4105-aa8a-17cfd0d22aa4@googlegroups.com>
	<mailman.2349.1369829480.3114.python-list@python.org>
Message-ID: <ea907a83-e2a6-4654-858d-7e96b6733bf7@be10g2000pbd.googlegroups.com>

On May 29, 5:11?pm, F?bio Santos <fabiosantos... at gmail.com> wrote:
> On 29 May 2013 12:25, "Avnesh Shakya" <avnesh.n... at gmail.com> wrote:
>
>
>
>
>
>
>
>
>
> > hi,
> > ? ?I am trying to display my output with different colour on terminal,
> but it's
> > coming with that colour code.
> > Please help me how is it possible?
>
> > my code is -
> > from fabric.colors import green, red, blue
> > def colorr():
> > ? ? a = red('This is red')
> > ? ? b = green('This is green')
> > ? ? c = blue('This is blue')
> > ? ? d = {a, b, c}
> > ? ? print d
> > colorr()
>
> > output -
> > set(['\x1b[32mThis is green\x1b[0m', '\x1b[34mThis is blue\x1b[0m',
>
> '\x1b[31mThis is red\x1b[0m'])
>
>
>
> > Thanks
>
> You are printing the {a, b, c} set. That ends up printing the repr of all
> of its contents. The repr breaks the desired output. Try to just
>
> print a, b, c

Or

for x in d: print x
should work


From joshua.landau.ws at gmail.com  Wed May 29 07:48:39 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Wed, 29 May 2013 12:48:39 +0100
Subject: Fatal Python error
Message-ID: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>

Hello all, again. Instead of revising like I'm meant to be, I've been
delving into a bit of Python and I've come up with this code:

class ClassWithProperty:
 @property
def property(self):
pass

thingwithproperty = ClassWithProperty()

def loop():
try:
thingwithproperty.property
 except:
pass

loop()

try:
loop()
except RuntimeError:
pass

As you will expect, this does nothing... on Python2.7 and PyPy. Python3.3
prefers to spit out a "Fatal Python error: Cannot recover from stack
overflow.", which seems a bit unexpected.

Wuzzup with that?
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From davea at davea.name  Wed May 29 08:25:13 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 29 May 2013 08:25:13 -0400
Subject: Fatal Python error
In-Reply-To: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
Message-ID: <51A5F3A9.3050709@davea.name>

On 05/29/2013 07:48 AM, Joshua Landau wrote:
> Hello all, again. Instead of revising like I'm meant to be, I've been
> delving into a bit of Python and I've come up with this code:
>

To start with, please post in text mode.  By using html, you've 
completely messed up any indentation you presumably had.

> class ClassWithProperty:
>   @property
> def property(self):
> pass

Did you really mean to hide the built-in property?  I don't know if this 
does that, but it's certainly confusing.  And perhaps that's a 
difference between 2.x and 3.x

>
> thingwithproperty = ClassWithProperty()
>
> def loop():
> try:
> thingwithproperty.property
>   except:
> pass
>
> loop()
>
> try:
> loop()
> except RuntimeError:
> pass
>
> As you will expect, this does nothing... on Python2.7 and PyPy. Python3.3
> prefers to spit out a "Fatal Python error: Cannot recover from stack
> overflow.", which seems a bit unexpected.
>

A stack overflow means you have infinite recursion.  Try fixing the 
property name above, and see if that makes a difference.



-- 
DaveA


From joshua.landau.ws at gmail.com  Wed May 29 08:43:48 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Wed, 29 May 2013 13:43:48 +0100
Subject: Fatal Python error
In-Reply-To: <51A5F3A9.3050709@davea.name>
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
	<51A5F3A9.3050709@davea.name>
Message-ID: <CAN1F8qVPY4=TgUdcM=p9gGnO_r70i23FZU0iL7Yn57FAHev7Qg@mail.gmail.com>

On 29 May 2013 13:25, Dave Angel <davea at davea.name> wrote:

> On 05/29/2013 07:48 AM, Joshua Landau wrote:
>
>> Hello all, again. Instead of revising like I'm meant to be, I've been
>> delving into a bit of Python and I've come up with this code:
>>
>>
> To start with, please post in text mode.  By using html, you've completely
> messed up any indentation you presumably had.


Appologies, I use GMail and I don't know how to force text-only


>  class ClassWithProperty:
>>   @property
>> def property(self):
>> pass
>>
>
> Did you really mean to hide the built-in property?  I don't know if this
> does that, but it's certainly confusing.  And perhaps that's a difference
> between 2.x and 3.x


I'm not. That goes to self.property, whilst the normal function isn't. I
guess it does locally hide it, but who really cares? :P

You can rename it if you want. Anything will do. Obviously this is a
minimal example code, and not the real thing.

 As you will expect, this does nothing... on Python2.7 and PyPy. Python3.3
>> prefers to spit out a "Fatal Python error: Cannot recover from stack
>> overflow.", which seems a bit unexpected.
>>
>>
> A stack overflow means you have infinite recursion.


I realise, but I was hoping to catch that with the "except RuntimeError".


> Try fixing the property name above, and see if that makes a difference.


It does not make a difference.
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From rustompmody at gmail.com  Wed May 29 10:47:15 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 29 May 2013 07:47:15 -0700 (PDT)
Subject: Fatal Python error
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
	<51A5F3A9.3050709@davea.name>
	<mailman.2352.1369831470.3114.python-list@python.org>
Message-ID: <ebe97e33-7a88-43a9-9e3f-a06ac644f795@bw5g2000pbd.googlegroups.com>

On May 29, 5:43?pm, Joshua Landau <joshua.landau... at gmail.com> wrote:
> On 29 May 2013 13:25, Dave Angel <da... at davea.name> wrote:
>
> > On 05/29/2013 07:48 AM, Joshua Landau wrote:
>
> >> Hello all, again. Instead of revising like I'm meant to be, I've been
> >> delving into a bit of Python and I've come up with this code:
>
> > To start with, please post in text mode. ?By using html, you've completely
> > messed up any indentation you presumably had.
>
> Appologies, I use GMail and I don't know how to force text-only

In gmail
New interface:
There should be a down arrow next to the trash-can right bottom of
posting-screen
Click the down-arrow. YOu should see a 'choose text-only' option

Old interface:
When posting a new message, right at the top next to all the
formatting icons is a text-only link


From marcelgmr at gmail.com  Wed May 29 08:30:58 2013
From: marcelgmr at gmail.com (Marcel Rodrigues)
Date: Wed, 29 May 2013 09:30:58 -0300
Subject: Fatal Python error
In-Reply-To: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
Message-ID: <CAFEv2m6DdXK-c1YLn+6D5E1RHZ+p-AQ=2eqEh7c6Ls61+=ZAhQ@mail.gmail.com>

I just tried your code with similar results: it does nothing on PyPy
2.0.0-beta2 and Python 2.7.4. But on Python 3.3.1 it caused core dump.
It's a little weird but so is the code. You have defined a function that
calls itself unconditionally. This will cause a stack overflow, which is a
RuntimeError.
 Since you are handling this very exception with a pass statement, we would
expect that no error occurs. But the fatal error message seems pretty
informative at this point: "Cannot recover from stack overflow.".

One thing to note is that while it's reasonable to handle exceptions that
happens at the level of your Python code, like a ValueError, it's not so
reasonable to try to handle something that may disturb the interpreter
itself in a lower level, like a stack overflow (I think that the stack used
by your code is the same stack used by the interpreter code, but I'm not
sure).


2013/5/29 Joshua Landau <joshua.landau.ws at gmail.com>

> Hello all, again. Instead of revising like I'm meant to be, I've been
> delving into a bit of Python and I've come up with this code:
>
> class ClassWithProperty:
>  @property
> def property(self):
> pass
>
> thingwithproperty = ClassWithProperty()
>
> def loop():
> try:
> thingwithproperty.property
>  except:
> pass
>
> loop()
>
> try:
> loop()
> except RuntimeError:
> pass
>
> As you will expect, this does nothing... on Python2.7 and PyPy. Python3.3
> prefers to spit out a "Fatal Python error: Cannot recover from stack
> overflow.", which seems a bit unexpected.
>
> Wuzzup with that?
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>
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From joshua.landau.ws at gmail.com  Wed May 29 09:02:54 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Wed, 29 May 2013 14:02:54 +0100
Subject: Fatal Python error
In-Reply-To: <CAFEv2m6DdXK-c1YLn+6D5E1RHZ+p-AQ=2eqEh7c6Ls61+=ZAhQ@mail.gmail.com>
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
	<CAFEv2m6DdXK-c1YLn+6D5E1RHZ+p-AQ=2eqEh7c6Ls61+=ZAhQ@mail.gmail.com>
Message-ID: <CAN1F8qU0hF2pBqDt5xRP_Gg7kqpbeFGkuLftX2a5b21ibB1o-g@mail.gmail.com>

On 29 May 2013 13:30, Marcel Rodrigues <marcelgmr at gmail.com> wrote:
>
> I just tried your code with similar results: it does nothing on PyPy
2.0.0-beta2 and Python 2.7.4. But on Python 3.3.1 it caused core dump.
> It's a little weird but so is the code. You have defined a function that
calls itself unconditionally. This will cause a stack overflow, which is a
RuntimeError.


The weirdness of the code is simply as I've taken all the logic and
conditionality away, since it was irrelevant. Why, though, does removing
any one element make it fail properly? That's what's confusing, largely.

>
>  Since you are handling this very exception with a pass statement, we
would expect that no error occurs. But the fatal error message seems pretty
informative at this point: "Cannot recover from stack overflow.".
>
> One thing to note is that while it's reasonable to handle exceptions that
happens at the level of your Python code, like a ValueError, it's not so
reasonable to try to handle something that may disturb the interpreter
itself in a lower level, like a stack overflow (I think that the stack used
by your code is the same stack used by the interpreter code, but I'm not
sure).


What is the expected response here then? Should I ever feel justified in
catching a Stack Overflow error? This code was extracted from a file
manager after much difficulty, but it should have been "caught" by a global
try...except and not crashed the whole program immediately. I'd imagine
that's a good enough reason to bring this up.



Also;
This works for the code:

def loop():
    thingwithproperty.prop
    loop()

This does not:

def loop():
    try:
        thingwithproperty.prop
    except:
        pass
loop()

thingwithproperty.prop NEVER creates an error.
(.prop is the new .property)
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From marcelgmr at gmail.com  Wed May 29 09:22:23 2013
From: marcelgmr at gmail.com (Marcel Rodrigues)
Date: Wed, 29 May 2013 10:22:23 -0300
Subject: Fatal Python error
In-Reply-To: <CAN1F8qU0hF2pBqDt5xRP_Gg7kqpbeFGkuLftX2a5b21ibB1o-g@mail.gmail.com>
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
	<CAFEv2m6DdXK-c1YLn+6D5E1RHZ+p-AQ=2eqEh7c6Ls61+=ZAhQ@mail.gmail.com>
	<CAN1F8qU0hF2pBqDt5xRP_Gg7kqpbeFGkuLftX2a5b21ibB1o-g@mail.gmail.com>
Message-ID: <CAFEv2m7Y96NcXTJnirH6ZxxLWuZ+UNpFW59ZqySBUUPEKWt+aQ@mail.gmail.com>

I think the issue here has little to do with classes/objects/properties.
See, for example, the code posted by Oscar Benjamin.

What that code is trying to do is similar to responding to an "Out Of
Memory" error with something that might require more memory allocation.

Even if we consider the Py3 behavior here a bug, that code is unreliable by
design. It's an infinite loop at the best.


2013/5/29 Joshua Landau <joshua.landau.ws at gmail.com>

> On 29 May 2013 13:30, Marcel Rodrigues <marcelgmr at gmail.com> wrote:
> >
> > I just tried your code with similar results: it does nothing on PyPy
> 2.0.0-beta2 and Python 2.7.4. But on Python 3.3.1 it caused core dump.
> > It's a little weird but so is the code. You have defined a function that
> calls itself unconditionally. This will cause a stack overflow, which is a
> RuntimeError.
>
>
> The weirdness of the code is simply as I've taken all the logic and
> conditionality away, since it was irrelevant. Why, though, does removing
> any one element make it fail properly? That's what's confusing, largely.
>
>
> >
> >  Since you are handling this very exception with a pass statement, we
> would expect that no error occurs. But the fatal error message seems pretty
> informative at this point: "Cannot recover from stack overflow.".
> >
> > One thing to note is that while it's reasonable to handle exceptions
> that happens at the level of your Python code, like a ValueError, it's not
> so reasonable to try to handle something that may disturb the interpreter
> itself in a lower level, like a stack overflow (I think that the stack used
> by your code is the same stack used by the interpreter code, but I'm not
> sure).
>
>
> What is the expected response here then? Should I ever feel justified in
> catching a Stack Overflow error? This code was extracted from a file
> manager after much difficulty, but it should have been "caught" by a global
> try...except and not crashed the whole program immediately. I'd imagine
> that's a good enough reason to bring this up.
>
>
>
> Also;
> This works for the code:
>
> def loop():
>     thingwithproperty.prop
>     loop()
>
> This does not:
>
> def loop():
>     try:
>         thingwithproperty.prop
>     except:
>         pass
> loop()
>
> thingwithproperty.prop NEVER creates an error.
> (.prop is the new .property)
>
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From oscar.j.benjamin at gmail.com  Wed May 29 08:45:14 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Wed, 29 May 2013 13:45:14 +0100
Subject: Fatal Python error
In-Reply-To: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
Message-ID: <CAHVvXxTxzZjhsmDw3x0Wm-wyLmdx5VehzKahnfkTSNrmigKMUA@mail.gmail.com>

On 29 May 2013 12:48, Joshua Landau <joshua.landau.ws at gmail.com> wrote:
> Hello all, again. Instead of revising like I'm meant to be, I've been
> delving into a bit of Python and I've come up with this code:

Here's a simpler example that gives similar results:

$ py -3.3
Python 3.3.2 (v3.3.2:d047928ae3f6, May 16 2013, 00:03:43) [MSC v.1600
32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> def broken():
...   try:
...     broken()
...   except RuntimeError:
...     broken()
...
>>> broken()
Fatal Python error: Cannot recover from stack overflow.

Current thread 0x0000058c:
  File "<stdin>", line 3 in broken
  File "<stdin>", line 3 in broken
...

Under Python 2.7.5 it just goes into an infinite loop. Under Python
3.2.5 and 3.3.2 it crashes the interpreter as shown above.

What the broken() function is doing is totally stupid: responding to a
recursion error with more recursion. However this may indicate or be
considered a bug in the 3.x interpreter.


Oscar


From davea at davea.name  Wed May 29 09:02:53 2013
From: davea at davea.name (Dave Angel)
Date: Wed, 29 May 2013 09:02:53 -0400
Subject: Fatal Python error
In-Reply-To: <CAHVvXxTxzZjhsmDw3x0Wm-wyLmdx5VehzKahnfkTSNrmigKMUA@mail.gmail.com>
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
	<CAHVvXxTxzZjhsmDw3x0Wm-wyLmdx5VehzKahnfkTSNrmigKMUA@mail.gmail.com>
Message-ID: <51A5FC7D.8080202@davea.name>

On 05/29/2013 08:45 AM, Oscar Benjamin wrote:
> On 29 May 2013 12:48, Joshua Landau <joshua.landau.ws at gmail.com> wrote:
>> Hello all, again. Instead of revising like I'm meant to be, I've been
>> delving into a bit of Python and I've come up with this code:
>
> Here's a simpler example that gives similar results:
>
> $ py -3.3
> Python 3.3.2 (v3.3.2:d047928ae3f6, May 16 2013, 00:03:43) [MSC v.1600
> 32 bit (Intel)] on win32
> Type "help", "copyright", "credits" or "license" for more information.
>>>> def broken():
> ...   try:
> ...     broken()
> ...   except RuntimeError:
> ...     broken()
> ...
>>>> broken()
> Fatal Python error: Cannot recover from stack overflow.
>
> Current thread 0x0000058c:
>    File "<stdin>", line 3 in broken
>    File "<stdin>", line 3 in broken
> ...
>
> Under Python 2.7.5 it just goes into an infinite loop. Under Python
> 3.2.5 and 3.3.2 it crashes the interpreter as shown above.
>
> What the broken() function is doing is totally stupid: responding to a
> recursion error with more recursion. However this may indicate or be
> considered a bug in the 3.x interpreter.
>
>
> Oscar
>

More likely a bug in the 2.x interpreter.  Once inside an exception 
handler, that frame must be held somehow.  If not on the stack, then in 
some separate list.  So the logic will presumably fill memory, it just 
may take longer on 2.x .

Joshua:  Avoid doing anything complex inside an exception handler.  If 
nothing else, the exception frame is huge.  I probably would have 
spotted it except for the indentation problem triggered by html.  The 
top level code following your function didn't have any loops, so it 
wasn't a problem.

Can anyone help Joshua put his gmail into text mode?




-- 
DaveA


From joshua.landau.ws at gmail.com  Wed May 29 10:05:52 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Wed, 29 May 2013 15:05:52 +0100
Subject: Fatal Python error
In-Reply-To: <51A5FC7D.8080202@davea.name>
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
	<CAHVvXxTxzZjhsmDw3x0Wm-wyLmdx5VehzKahnfkTSNrmigKMUA@mail.gmail.com>
	<51A5FC7D.8080202@davea.name>
Message-ID: <CAN1F8qUZ1+BxGPDzFjWrgz7RwQxuaWfgitsYgH9novThed=gXQ@mail.gmail.com>

On 29 May 2013 14:02, Dave Angel <davea at davea.name> wrote:

> On 05/29/2013 08:45 AM, Oscar Benjamin wrote:
> Joshua:  Avoid doing anything complex inside an exception handler.


Unfortunately, Ranger (the file manager in question) wraps a lot of stuff
in one big exception handler. Hence there isn't much choice. The original
wasn't actually in an infinite recursion, too, but just a recursion over a
large directory.

Is there a reason that Python 3 can't be made to work like Python 2 and
PyPy, and -if not- should it? The catchable fail would be much nicer than
just bombing the program.

In the meantime the algorithm should just be reworked, but it seems like a
larger step than should be needed.

If nothing else, the exception frame is huge.  I probably would have
> spotted it except for the indentation problem triggered by html.  The top
> level code following your function didn't have any loops, so it wasn't a
> problem.
>
> Can anyone help Joshua put his gmail into text mode?


I've found a new option. As a test, here's a simplified version without the
property:

def loop():
    try:
        (lambda: None)()
    except:
        pass

    loop()

try:
    loop()
except RuntimeError:
    pass

which is pretty much Oscar Benjamin's, but less stupid.
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From oscar.j.benjamin at gmail.com  Wed May 29 11:17:58 2013
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Wed, 29 May 2013 16:17:58 +0100
Subject: Fatal Python error
In-Reply-To: <51A5FC7D.8080202@davea.name>
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
	<CAHVvXxTxzZjhsmDw3x0Wm-wyLmdx5VehzKahnfkTSNrmigKMUA@mail.gmail.com>
	<51A5FC7D.8080202@davea.name>
Message-ID: <CAHVvXxRtGBgM6w3ry75_21yFxvQ6YKx4qqpBasy5tUspsbZUFQ@mail.gmail.com>

On 29 May 2013 14:02, Dave Angel <davea at davea.name> wrote:
> On 05/29/2013 08:45 AM, Oscar Benjamin wrote:
>
> More likely a bug in the 2.x interpreter.  Once inside an exception handler,
> that frame must be held somehow.  If not on the stack, then in some separate
> list.  So the logic will presumably fill memory, it just may take longer on
> 2.x .

I'm not so sure. The following gives the same behaviour in 2.7, 3.2 and 3.3:

$ cat tmp.py
def loop():
    loop()

loop()

$ py -3.2 tmp.py
Traceback (most recent call last):
  File "tmp.py", line 4, in <module>
    loop()
  File "tmp.py", line 2, in loop
    loop()
  File "tmp.py", line 2, in loop
    loop()
  File "tmp.py", line 2, in loop
    loop()
  File "tmp.py", line 2, in loop
...

However the following leads to a RuntimeError in 2.7 but different
stack overflow errors in 3.2 and 3.3:

$ cat tmp.py
def loop():
    try:
        (lambda: None)()
    except RuntimeError:
        pass
    loop()

loop()

$ py -2.7 tmp.py
Traceback (most recent call last):
  File "tmp.py", line 8, in <module>
    loop()
  File "tmp.py", line 6, in loop
    loop()
  File "tmp.py", line 6, in loop
    loop()
  File "tmp.py", line 6, in loop
    loop()
  File "tmp.py", line 6, in loop
...
RuntimeError: maximum recursion depth exceeded

$ py -3.2 tmp.py
Fatal Python error: Cannot recover from stack overflow.

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.

$ py -3.3 tmp.py
Fatal Python error: Cannot recover from stack overflow.

Current thread 0x000005c4:
  File "tmp.py", line 3 in loop
  File "tmp.py", line 6 in loop
  File "tmp.py", line 6 in loop
  File "tmp.py", line 6 in loop
  File "tmp.py", line 6 in loop
  File "tmp.py", line 6 in loop
  File "tmp.py", line 6 in loop
...

I would expect this to give "RuntimeError: maximum recursion depth
exceeded" in all three cases.


Oscar


From pruebauno at latinmail.com  Fri May 31 10:31:44 2013
From: pruebauno at latinmail.com (nn)
Date: Fri, 31 May 2013 07:31:44 -0700 (PDT)
Subject: Fatal Python error
References: <CAN1F8qXPEM4B=2e7KOhWeTKzxmeeb_w_S97wYiHCMXH3jfzL6g@mail.gmail.com>
	<CAHVvXxTxzZjhsmDw3x0Wm-wyLmdx5VehzKahnfkTSNrmigKMUA@mail.gmail.com>
	<51A5FC7D.8080202@davea.name>
	<mailman.2358.1369836402.3114.python-list@python.org>
Message-ID: <25cc650c-9047-4533-bf8d-cf5b8dcf6a05@v2g2000yqa.googlegroups.com>

On May 29, 10:05?am, Joshua Landau <joshua.landau... at gmail.com> wrote:
> On 29 May 2013 14:02, Dave Angel <da... at davea.name> wrote:
>
> > On 05/29/2013 08:45 AM, Oscar Benjamin wrote:
> > Joshua: ?Avoid doing anything complex inside an exception handler.
>
> Unfortunately, Ranger (the file manager in question) wraps a lot of stuff
> in one big exception handler. Hence there isn't much choice. The original
> wasn't actually in an infinite recursion, too, but just a recursion over a
> large directory.
>
> Is there a reason that Python 3 can't be made to work like Python 2 and
> PyPy, and -if not- should it? The catchable fail would be much nicer than
> just bombing the program.
>
> In the meantime the algorithm should just be reworked, but it seems like a
> larger step than should be needed.
>
> If nothing else, the exception frame is huge. ?I probably would have
>
> > spotted it except for the indentation problem triggered by html. ?The top
> > level code following your function didn't have any loops, so it wasn't a
> > problem.
>
> > Can anyone help Joshua put his gmail into text mode?
>
> I've found a new option. As a test, here's a simplified version without the
> property:
>
> def loop():
> ? ? try:
> ? ? ? ? (lambda: None)()
> ? ? except:
> ? ? ? ? pass
>
> ? ? loop()
>
> try:
> ? ? loop()
> except RuntimeError:
> ? ? pass
>
> which is pretty much Oscar Benjamin's, but less stupid.

If nobody else has, I would recommend you submit a bug at
bugs.python.org.


From croepha at gmail.com  Wed May 29 13:46:19 2013
From: croepha at gmail.com (Croepha)
Date: Wed, 29 May 2013 12:46:19 -0500
Subject: Getting a callable for any value?
Message-ID: <CANm61jeHSZL1FQvTr9FS0QKEhFPXug0fibXBEA-4guYF1Lf7UQ@mail.gmail.com>

Is there anything like this in the standard library?

class AnyFactory(object):
def __init__(self, anything):
self.product = anything
def __call__(self):
return self.product
def __repr__(self):
return "%s.%s(%r)" % (self.__class__.__module__, self.__class__.__name__,
self.product)

my use case is:
collections.defaultdict(AnyFactory(collections.defaultdict(AnyFactory(None))))

And I think lambda expressions are not preferable...

I found itertools.repeat(anything).next and functools.partial(copy.copy,
anything)

but both of those don't repr well... and are confusing...

I think AnyFactory is the most readable, but is confusing if the reader
doesn't know what it is, am I missing a standard implementation of this?
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From andrea.crotti.0 at gmail.com  Wed May 29 13:55:51 2013
From: andrea.crotti.0 at gmail.com (andrea crotti)
Date: Wed, 29 May 2013 18:55:51 +0100
Subject: Getting a callable for any value?
In-Reply-To: <CANm61jeHSZL1FQvTr9FS0QKEhFPXug0fibXBEA-4guYF1Lf7UQ@mail.gmail.com>
References: <CANm61jeHSZL1FQvTr9FS0QKEhFPXug0fibXBEA-4guYF1Lf7UQ@mail.gmail.com>
Message-ID: <51A64127.2020600@gmail.com>

On 05/29/2013 06:46 PM, Croepha wrote:
> Is there anything like this in the standard library?
>
> class AnyFactory(object):
> def __init__(self, anything):
> self.product = anything
> def __call__(self):
> return self.product
> def __repr__(self):
> return "%s.%s(%r)" % (self.__class__.__module__, 
> self.__class__.__name__, self.product)
>
> my use case is: 
> collections.defaultdict(AnyFactory(collections.defaultdict(AnyFactory(None))))
>

I think I would scratch my head for a good half an hour if I see a 
string like this, so I hope there isn't anything in the standard library 
to do that :D
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From ned at nedbatchelder.com  Wed May 29 14:10:58 2013
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Wed, 29 May 2013 14:10:58 -0400
Subject: Getting a callable for any value?
In-Reply-To: <CANm61jeHSZL1FQvTr9FS0QKEhFPXug0fibXBEA-4guYF1Lf7UQ@mail.gmail.com>
References: <CANm61jeHSZL1FQvTr9FS0QKEhFPXug0fibXBEA-4guYF1Lf7UQ@mail.gmail.com>
Message-ID: <51A644B2.6090800@nedbatchelder.com>

On 5/29/2013 1:46 PM, Croepha wrote:
> Is there anything like this in the standard library?
>
> class AnyFactory(object):
> def __init__(self, anything):
> self.product = anything
> def __call__(self):
> return self.product
> def __repr__(self):
> return "%s.%s(%r)" % (self.__class__.__module__, 
> self.__class__.__name__, self.product)
>
> my use case is: 
> collections.defaultdict(AnyFactory(collections.defaultdict(AnyFactory(None))))
>
> And I think lambda expressions are not preferable...
>

It's not clear to me that this does what you want.  Won't your 
defaultdict use the same defaultdict for all of its default values? This 
is hard to describe in English but:

     d = collections.defaultdict(AnyFactory(collections.defaultdict(AnyFactory(None))))

     d[1][1] = 1
     d[2][2] = 2

     print d[1]
     #->  defaultdict(__main__.AnyFactory(None), {1: 1, 2: 2})
     print d[1] is d[2]
     #->  True

It might not be possible to get this right without lambdas:

     d = collections.defaultdict(lambda: collections.defaultdict(lambda: None))

     d[1][1] = 1
     d[2][2] = 2

     print d[1]
     #->  defaultdict(<function <lambda> at 0x02091D70>, {1: 1})
     print d[1] is d[2]
     #->  False


--Ned.

> I found itertools.repeat(anything).next and 
> functools.partial(copy.copy, anything)
>
> but both of those don't repr well... and are confusing...
>
> I think AnyFactory is the most readable, but is confusing if the 
> reader doesn't know what it is, am I missing a standard implementation 
> of this?
>
>
>

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From fabiosantosart at gmail.com  Wed May 29 14:19:28 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Wed, 29 May 2013 19:19:28 +0100
Subject: Getting a callable for any value?
Message-ID: <CAA=1kxRDu5CCL-MNj-K4hG2Xrex5tM6x-C=U+h5-Mwy3dqDuOw@mail.gmail.com>

On 29 May 2013 18:51, "Croepha" <croepha at gmail.com> wrote:
>
> Is there anything like this in the standard library?
>
> class AnyFactory(object):
> def __init__(self, anything):
> self.product = anything
> def __call__(self):
> return self.product
> def __repr__(self):
> return "%s.%s(%r)" % (self.__class__.__module__, self.__class__.__name__,
self.product)
>
> my use case is:
collections.defaultdict(AnyFactory(collections.defaultdict(AnyFactory(None))))
>
> And I think lambda expressions are not preferable...
>
> I found itertools.repeat(anything).next and functools.partial(copy.copy,
anything)
>
> but both of those don't repr well... and are confusing...
>
> I think AnyFactory is the most readable, but is confusing if the reader
doesn't know what it is, am I missing a standard implementation of this?
>
>

Are you sure you don't want to use a lambda expression? They are pretty
pythonic.

none_factory = lambda: None
defaultdict_none_factory = lambda: defaultdict(none_factory)

collections.defaultdict(defaultdict_none_factory)

Just what are you trying to do?
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From ian.g.kelly at gmail.com  Wed May 29 14:24:31 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 29 May 2013 12:24:31 -0600
Subject: Getting a callable for any value?
In-Reply-To: <CAA=1kxRDu5CCL-MNj-K4hG2Xrex5tM6x-C=U+h5-Mwy3dqDuOw@mail.gmail.com>
References: <CAA=1kxRDu5CCL-MNj-K4hG2Xrex5tM6x-C=U+h5-Mwy3dqDuOw@mail.gmail.com>
Message-ID: <CALwzidkPzXBM9EH8Rd7S9rTqXHgvC4W+yywmBgerVp_bOO+iOQ@mail.gmail.com>

On Wed, May 29, 2013 at 12:19 PM, F?bio Santos <fabiosantosart at gmail.com> wrote:
> Are you sure you don't want to use a lambda expression? They are pretty
> pythonic.
>
> none_factory = lambda: None
> defaultdict_none_factory = lambda: defaultdict(none_factory)
>
> collections.defaultdict(defaultdict_none_factory)

Gah.  If you're going to go to the trouble of assigning a name to the
lambda, then just use a def statement:

def none_factory: return None
def defaultdict_none_factory: return defaultdict(none_factory)

collections.defaultdict(defaultdict_none_factory)


From ian.g.kelly at gmail.com  Wed May 29 14:20:02 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 29 May 2013 12:20:02 -0600
Subject: Getting a callable for any value?
In-Reply-To: <CANm61jeHSZL1FQvTr9FS0QKEhFPXug0fibXBEA-4guYF1Lf7UQ@mail.gmail.com>
References: <CANm61jeHSZL1FQvTr9FS0QKEhFPXug0fibXBEA-4guYF1Lf7UQ@mail.gmail.com>
Message-ID: <CALwzidmONKYaMw-m2ScSBW2rfGrfn0Zet6jAzVT7S0nvCfGyAw@mail.gmail.com>

On Wed, May 29, 2013 at 11:46 AM, Croepha <croepha at gmail.com> wrote:
> Is there anything like this in the standard library?
>
> class AnyFactory(object):
> def __init__(self, anything):
> self.product = anything
> def __call__(self):
> return self.product
> def __repr__(self):
> return "%s.%s(%r)" % (self.__class__.__module__, self.__class__.__name__,
> self.product)

In other words, the function (lambda: x) with a repr that tells you
what x is?  Not that I'm aware of, but you could just do something
like:

def return_x(): return x

And then the repr will include the name "return_x", which will give
you a hint as to what it does.

Also, "AnyFactory" is a misleading name because the class above is not
a factory.

> my use case is:
> collections.defaultdict(AnyFactory(collections.defaultdict(AnyFactory(None))))
>
> And I think lambda expressions are not preferable...

What you have above is actually buggy.  Your "AnyFactory" will always
return the *same instance* of the passed in defaultdict, which means
that no matter what key you give to the outer defaultdict, you always
get the same inner defaultdict.

Anyway, I think it's clearer with lambdas:

defaultdict(lambda: defaultdict(lambda: None))

But I can see your point about the repr.  You could do something like this:

class NoneDefaultDict(dict):
    def __missing__(self, key):
        return None
    def __repr__(self):
        return "NoneDefaultDict(%s)" % super(NoneDefaultDict, self).__repr__()

some_dict = defaultdict(NoneDefaultDict)


From steve+comp.lang.python at pearwood.info  Thu May 30 02:41:01 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 06:41:01 GMT
Subject: Getting a callable for any value?
References: <mailman.2367.1369849583.3114.python-list@python.org>
Message-ID: <51a6f47d$0$11118$c3e8da3@news.astraweb.com>

On Wed, 29 May 2013 12:46:19 -0500, Croepha wrote:

> Is there anything like this in the standard library?
> 
> class AnyFactory(object):
>     def __init__(self, anything):
>         self.product = anything
>     def __call__(self):
>         return self.product
>     def __repr__(self):
>         return "%s.%s(%r)" % (self.__class__.__module__,
>         self.__class__.__name__, self.product)
> 
> my use case is:
> collections.defaultdict(AnyFactory(collections.defaultdict(
> AnyFactory(None))))

That's not a use-case. That's a code snippet. What does it mean? Why 
would you write such an ugly thing? What does it do? I get a headache 
just looking at it.

I *think* it's a defaultdict that returns a defaultdict on KeyError, 
where the *second* defaultdict returns None.

from collections import defaultdict
defaultdict(lambda: defaultdict(lambda: None))

looks more reasonable to me. I don't know why you need to wrap such a 
simple pair of functions in a class. This is not Java.


http://steve-yegge.blogspot.com.au/2006/03/execution-in-kingdom-of-nouns.html

(Twice in one day I have linked to this.)


I'm not sure why you care about the repr of the "AnythingFactory" object. 
You stuff it directly into the defaultdict, where you are very unlikely 
to need to inspect it. You only ever see the defaultdicts they return, 
and they already have a nice repr.



-- 
Steven


From damage3025 at gmail.com  Wed May 29 14:23:28 2013
From: damage3025 at gmail.com (Ma Xiaojun)
Date: Thu, 30 May 2013 02:23:28 +0800
Subject: The state of pySerial
Message-ID: <CAGVx7UVrvZUzwYAyj8Yj+1wOm9q_jf_UDwYLgx2u1w+Vv1-rLQ@mail.gmail.com>

Hi, all.

pySerial is probably "the solution" for serial port programming.
Physical serial port is dead on PC but USB-to-Serial give it a second
life. Serial port stuff won't interest end users at all. But it is
still used in the EE world and so on. Arduino uses it to upload
programs. Sensors may use serial port to communicate with PC. GSM
Modem also uses serial port to communicate with PC.

Unforunately, pySerial project doesn't seem to have a good state. I
find pySerial + Python 3.3 broken on my machine (Python 2.7 is OK) .
There are unanswered outstanding bugs, PyPI page has 2.6 while SF
homepage still gives 2.5.

Any idea?


From invalid at invalid.invalid  Wed May 29 15:47:30 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 29 May 2013 19:47:30 +0000 (UTC)
Subject: The state of pySerial
References: <mailman.2372.1369851830.3114.python-list@python.org>
Message-ID: <ko5m0i$o5u$1@reader1.panix.com>

On 2013-05-29, Ma Xiaojun <damage3025 at gmail.com> wrote:

> pySerial is probably "the solution" for serial port programming.
> Physical serial port is dead on PC but USB-to-Serial give it a second
> life. Serial port stuff won't interest end users at all. But it is
> still used in the EE world and so on. Arduino uses it to upload
> programs. Sensors may use serial port to communicate with PC. GSM
> Modem also uses serial port to communicate with PC.
>
> Unforunately, pySerial project doesn't seem to have a good state. I
> find pySerial + Python 3.3 broken on my machine (Python 2.7 is OK) .
> There are unanswered outstanding bugs, PyPI page has 2.6 while SF
> homepage still gives 2.5.
>
> Any idea?

Volunteer as a maintainer and start fixing bugs?

I use pyserial regularly, and the current version works fine for me,
but I'm using Python 2.7. There are still too many libraries that
don't support 3.x for me to consider using 3.x for real work.

-- 
Grant Edwards               grant.b.edwards        Yow! They collapsed
                                  at               ... like nuns in the
                              gmail.com            street ... they had no
                                                   teen appeal!


From tjreedy at udel.edu  Wed May 29 17:46:25 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Wed, 29 May 2013 17:46:25 -0400
Subject: The state of pySerial
In-Reply-To: <ko5m0i$o5u$1@reader1.panix.com>
References: <mailman.2372.1369851830.3114.python-list@python.org>
	<ko5m0i$o5u$1@reader1.panix.com>
Message-ID: <ko5suv$hhv$1@ger.gmane.org>

On 5/29/2013 3:47 PM, Grant Edwards wrote:
> On 2013-05-29, Ma Xiaojun <damage3025 at gmail.com> wrote:
>
>> pySerial is probably "the solution" for serial port programming.
>> Physical serial port is dead on PC but USB-to-Serial give it a second
>> life. Serial port stuff won't interest end users at all. But it is
>> still used in the EE world and so on. Arduino uses it to upload
>> programs. Sensors may use serial port to communicate with PC. GSM
>> Modem also uses serial port to communicate with PC.
>>
>> Unforunately, pySerial project doesn't seem to have a good state. I
>> find pySerial + Python 3.3 broken on my machine (Python 2.7 is OK) .
>> There are unanswered outstanding bugs, PyPI page has 2.6 while SF
>> homepage still gives 2.5.
>>
>> Any idea?
>
> Volunteer as a maintainer and start fixing bugs?

It seems to be getting around 200 downloands a day. Quite worth someone 
supporting it.

> I use pyserial regularly, and the current version works fine for me,
> but I'm using Python 2.7. There are still too many libraries that
> don't support 3.x for me to consider using 3.x for real work.

The only download is a .exe. It it just the executable binary or is that 
a zip unpacker with source?





From invalid at invalid.invalid  Wed May 29 23:59:16 2013
From: invalid at invalid.invalid (Grant Edwards)
Date: Thu, 30 May 2013 03:59:16 +0000 (UTC)
Subject: The state of pySerial
References: <mailman.2372.1369851830.3114.python-list@python.org>
	<ko5m0i$o5u$1@reader1.panix.com>
	<mailman.2382.1369863984.3114.python-list@python.org>
Message-ID: <ko6iqk$31n$1@reader1.panix.com>

On 2013-05-29, Terry Jan Reedy <tjreedy at udel.edu> wrote:
> On 5/29/2013 3:47 PM, Grant Edwards wrote:
>> On 2013-05-29, Ma Xiaojun <damage3025 at gmail.com> wrote:
[...]
>>> Unforunately, pySerial project doesn't seem to have a good state. I
>>> find pySerial + Python 3.3 broken on my machine (Python 2.7 is OK) .
>>> There are unanswered outstanding bugs, PyPI page has 2.6 while SF
>>> homepage still gives 2.5.
>>>
>>> Any idea?
>>
>> Volunteer as a maintainer and start fixing bugs?
>
> It seems to be getting around 200 downloands a day. Quite worth
> someone supporting it.

Chris has a day job, just like the rest of us.  He might even have a
family and hobbies other than supporting pyserial. ;)

Everybody should feel free to submit patches for open bugs and to test
any patches waiting to be accepted.

>> I use pyserial regularly, and the current version works fine for me,
>> but I'm using Python 2.7. There are still too many libraries that
>> don't support 3.x for me to consider using 3.x for real work.
>
> The only download is a .exe. It it just the executable binary or is that 
> a zip unpacker with source?

http://pyserial.sourceforge.net/pyserial.html#from-source-tar-gz-or-checkout

https://pypi.python.org/packages/source/p/pyserial/pyserial-2.6.tar.gz#md5=cde799970b7c1ce1f7d6e9ceebe64c98

-- 
Grant



From wrw at mac.com  Wed May 29 16:00:58 2013
From: wrw at mac.com (William Ray Wing)
Date: Wed, 29 May 2013 16:00:58 -0400
Subject: The state of pySerial
In-Reply-To: <CAGVx7UVrvZUzwYAyj8Yj+1wOm9q_jf_UDwYLgx2u1w+Vv1-rLQ@mail.gmail.com>
References: <CAGVx7UVrvZUzwYAyj8Yj+1wOm9q_jf_UDwYLgx2u1w+Vv1-rLQ@mail.gmail.com>
Message-ID: <A979E66F-ACC8-4116-8F21-8F971545DCB8@mac.com>

On May 29, 2013, at 2:23 PM, Ma Xiaojun <damage3025 at gmail.com> wrote:

> Hi, all.
> 
> pySerial is probably "the solution" for serial port programming.
> Physical serial port is dead on PC but USB-to-Serial give it a second
> life. Serial port stuff won't interest end users at all. But it is
> still used in the EE world and so on. Arduino uses it to upload
> programs. Sensors may use serial port to communicate with PC. GSM
> Modem also uses serial port to communicate with PC.
> 
> Unforunately, pySerial project doesn't seem to have a good state. I
> find pySerial + Python 3.3 broken on my machine (Python 2.7 is OK) .
> There are unanswered outstanding bugs, PyPI page has 2.6 while SF
> homepage still gives 2.5.
> 
> Any idea?
> -- 
> http://mail.python.org/mailman/listinfo/python-list

Let me add another vote/request for pySerial support.  I've been using it with python 2.7 on OS-X, unaware that there wasn't a path forward to python 3.x.  If an external sensor absolutely positively has to be readable, then RS-232 is the only way to go.  USB interfaces can and do lock up if recovery from a power failure puts power on the external side before the computer has finished initializing the CPU side.  RS-232, bless its primitive heart, could care less.

Thanks,
Bill

From tjreedy at udel.edu  Wed May 29 17:38:33 2013
From: tjreedy at udel.edu (Terry Jan Reedy)
Date: Wed, 29 May 2013 17:38:33 -0400
Subject: The state of pySerial
In-Reply-To: <A979E66F-ACC8-4116-8F21-8F971545DCB8@mac.com>
References: <CAGVx7UVrvZUzwYAyj8Yj+1wOm9q_jf_UDwYLgx2u1w+Vv1-rLQ@mail.gmail.com>
	<A979E66F-ACC8-4116-8F21-8F971545DCB8@mac.com>
Message-ID: <ko5sg7$css$1@ger.gmane.org>

On 5/29/2013 4:00 PM, William Ray Wing wrote:
> On May 29, 2013, at 2:23 PM, Ma Xiaojun <damage3025 at gmail.com> wrote:
>
>> Hi, all.
>>
>> pySerial is probably "the solution" for serial port programming.
>> Physical serial port is dead on PC but USB-to-Serial give it a second
>> life. Serial port stuff won't interest end users at all. But it is
>> still used in the EE world and so on. Arduino uses it to upload
>> programs. Sensors may use serial port to communicate with PC. GSM
>> Modem also uses serial port to communicate with PC.
>>
>> Unforunately, pySerial project doesn't seem to have a good state. I
>> find pySerial + Python 3.3 broken on my machine (Python 2.7 is OK) .
>> There are unanswered outstanding bugs, PyPI page has 2.6 while SF
>> homepage still gives 2.5.
>>
>> Any idea?
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
> Let me add another vote/request for pySerial support.  I've been using it with python 2.7 on OS-X, unaware that there wasn't a path forward to python 3.x.  If an external sensor absolutely positively has to be readable, then RS-232 is the only way to go.  USB interfaces can and do lock up if recovery from a power failure puts power on the external side before the computer has finished initializing the CPU side.  RS-232, bless its primitive heart, could care less.

Then 'someone' should ask the author his intentions and offer to help or 
take over.

I did some RS-232 interfacing in the  1980s, and once past the fiddly 
start/stop/parity bit, baud rate, and wiring issues, I had a program run 
connected to multiple machines for years with no more interface problems.

Terry




From python at mrabarnett.plus.com  Wed May 29 18:34:47 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 29 May 2013 23:34:47 +0100
Subject: The state of pySerial
In-Reply-To: <ko5sg7$css$1@ger.gmane.org>
References: <CAGVx7UVrvZUzwYAyj8Yj+1wOm9q_jf_UDwYLgx2u1w+Vv1-rLQ@mail.gmail.com>
	<A979E66F-ACC8-4116-8F21-8F971545DCB8@mac.com>
	<ko5sg7$css$1@ger.gmane.org>
Message-ID: <51A68287.1010505@mrabarnett.plus.com>

On 29/05/2013 22:38, Terry Jan Reedy wrote:
> On 5/29/2013 4:00 PM, William Ray Wing wrote:
>> On May 29, 2013, at 2:23 PM, Ma Xiaojun <damage3025 at gmail.com> wrote:
>>
>>> Hi, all.
>>>
>>> pySerial is probably "the solution" for serial port programming.
>>> Physical serial port is dead on PC but USB-to-Serial give it a second
>>> life. Serial port stuff won't interest end users at all. But it is
>>> still used in the EE world and so on. Arduino uses it to upload
>>> programs. Sensors may use serial port to communicate with PC. GSM
>>> Modem also uses serial port to communicate with PC.
>>>
>>> Unforunately, pySerial project doesn't seem to have a good state. I
>>> find pySerial + Python 3.3 broken on my machine (Python 2.7 is OK) .
>>> There are unanswered outstanding bugs, PyPI page has 2.6 while SF
>>> homepage still gives 2.5.
>>>
>>> Any idea?
>>> --
>>> http://mail.python.org/mailman/listinfo/python-list
>>
>> Let me add another vote/request for pySerial support.  I've been using it with python 2.7 on OS-X, unaware that there wasn't a path forward to python 3.x.  If an external sensor absolutely positively has to be readable, then RS-232 is the only way to go.  USB interfaces can and do lock up if recovery from a power failure puts power on the external side before the computer has finished initializing the CPU side.  RS-232, bless its primitive heart, could care less.
>
> Then 'someone' should ask the author his intentions and offer to help or
> take over.
>
This page:

     http://pyserial.sourceforge.net/pyserial.html#requirements

says:

     "Python 2.3 or newer, including Python 3.x"

> I did some RS-232 interfacing in the  1980s, and once past the fiddly
> start/stop/parity bit, baud rate, and wiring issues, I had a program run
> connected to multiple machines for years with no more interface problems.
>



From damage3025 at gmail.com  Wed May 29 21:32:48 2013
From: damage3025 at gmail.com (Ma Xiaojun)
Date: Thu, 30 May 2013 09:32:48 +0800
Subject: The state of pySerial
In-Reply-To: <51A68287.1010505@mrabarnett.plus.com>
References: <CAGVx7UVrvZUzwYAyj8Yj+1wOm9q_jf_UDwYLgx2u1w+Vv1-rLQ@mail.gmail.com>
	<A979E66F-ACC8-4116-8F21-8F971545DCB8@mac.com>
	<ko5sg7$css$1@ger.gmane.org> <51A68287.1010505@mrabarnett.plus.com>
Message-ID: <CAGVx7UXEP2-FQdvbeYw_npvz6jJNbkD4KwY-ckz-DjHczQiRcA@mail.gmail.com>

I've already mailed the author, waiting for reply.

For Windows people, downloading a exe get you pySerial 2.5, which
list_ports and miniterm feature seems not included. To use 2.6,
download the tar.gz and use standard "setup.py install" to install it
(assume you have .py associated) . There is no C compiling involved in
the installation process.

For whether Python 3.3 is supported or not. I observed something like:
http://paste.ubuntu.com/5715275/ .

miniterm works for Python 3.3 at this time.


From python at mrabarnett.plus.com  Thu May 30 11:45:16 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 30 May 2013 16:45:16 +0100
Subject: The state of pySerial
In-Reply-To: <CAGVx7UXEP2-FQdvbeYw_npvz6jJNbkD4KwY-ckz-DjHczQiRcA@mail.gmail.com>
References: <CAGVx7UVrvZUzwYAyj8Yj+1wOm9q_jf_UDwYLgx2u1w+Vv1-rLQ@mail.gmail.com>
	<A979E66F-ACC8-4116-8F21-8F971545DCB8@mac.com>
	<ko5sg7$css$1@ger.gmane.org> <51A68287.1010505@mrabarnett.plus.com>
	<CAGVx7UXEP2-FQdvbeYw_npvz6jJNbkD4KwY-ckz-DjHczQiRcA@mail.gmail.com>
Message-ID: <51A7740C.9080402@mrabarnett.plus.com>

On 30/05/2013 02:32, Ma Xiaojun wrote:
> I've already mailed the author, waiting for reply.
>
> For Windows people, downloading a exe get you pySerial 2.5, which
> list_ports and miniterm feature seems not included. To use 2.6,
> download the tar.gz and use standard "setup.py install" to install it
> (assume you have .py associated) . There is no C compiling involved in
> the installation process.
>
> For whether Python 3.3 is supported or not. I observed something like:
> http://paste.ubuntu.com/5715275/ .
>
> miniterm works for Python 3.3 at this time.
>
The problem there is that 'desc' is a bytestring, but the regex pattern
can match only a Unicode string (Python 3 doesn't let you mix
bytestrings and Unicode string like a Python 2).

The simplest fix would probably be to decode 'desc' to Unicode.


From steve at terrafirma.us  Wed May 29 14:33:07 2013
From: steve at terrafirma.us (alcyon)
Date: Wed, 29 May 2013 11:33:07 -0700 (PDT)
Subject: python b'...' notation
Message-ID: <17dc2765-bc59-407a-9227-d67572411ad1@googlegroups.com>

This notation displays hex values except when they are 'printable', in which case it displays that printable character.  How do I get it to force hex for all bytes?  Thanks, Steve


From ian.g.kelly at gmail.com  Wed May 29 15:14:03 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 29 May 2013 13:14:03 -0600
Subject: python b'...' notation
In-Reply-To: <17dc2765-bc59-407a-9227-d67572411ad1@googlegroups.com>
References: <17dc2765-bc59-407a-9227-d67572411ad1@googlegroups.com>
Message-ID: <CALwzid=mdbD5n2-08uAsD5eRub3FadEOBYVS4NWmCQy7W+-XXQ@mail.gmail.com>

On Wed, May 29, 2013 at 12:33 PM, alcyon <steve at terrafirma.us> wrote:
> This notation displays hex values except when they are 'printable', in which case it displays that printable character.  How do I get it to force hex for all bytes?  Thanks, Steve

Is this what you want?

>>> ''.join('%02x' % x for x in b'hello world')
'68656c6c6f20776f726c64'


From cs at zip.com.au  Wed May 29 18:19:42 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Thu, 30 May 2013 08:19:42 +1000
Subject: python b'...' notation
In-Reply-To: <CALwzid=mdbD5n2-08uAsD5eRub3FadEOBYVS4NWmCQy7W+-XXQ@mail.gmail.com>
References: <CALwzid=mdbD5n2-08uAsD5eRub3FadEOBYVS4NWmCQy7W+-XXQ@mail.gmail.com>
Message-ID: <20130529221942.GA55776@cskk.homeip.net>

On 29May2013 13:14, Ian Kelly <ian.g.kelly at gmail.com> wrote:
| On Wed, May 29, 2013 at 12:33 PM, alcyon <steve at terrafirma.us> wrote:
| > This notation displays hex values except when they are 'printable', in which case it displays that printable character.  How do I get it to force hex for all bytes?  Thanks, Steve
| 
| Is this what you want?
| 
| >>> ''.join('%02x' % x for x in b'hello world')
| '68656c6c6f20776f726c64'

Not to forget binascii.hexlify.
-- 
Cameron Simpson <cs at zip.com.au>

Every particle continues in its state of rest or uniform motion in a straight
line except insofar as it doesn't.      - Sir Arther Eddington


From steve at terrafirma.us  Thu May 30 18:19:38 2013
From: steve at terrafirma.us (alcyon)
Date: Thu, 30 May 2013 15:19:38 -0700 (PDT)
Subject: python b'...' notation
In-Reply-To: <mailman.2384.1369866008.3114.python-list@python.org>
References: <CALwzid=mdbD5n2-08uAsD5eRub3FadEOBYVS4NWmCQy7W+-XXQ@mail.gmail.com>
	<mailman.2384.1369866008.3114.python-list@python.org>
Message-ID: <94eb93eb-3f95-448c-979a-5bfc4da9ef06@googlegroups.com>

On Wednesday, May 29, 2013 3:19:42 PM UTC-7, Cameron Simpson wrote:
> On 29May2013 13:14, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> 
> | On Wed, May 29, 2013 at 12:33 PM, alcyon <steve at terrafirma.us> wrote:
> 
> | > This notation displays hex values except when they are 'printable', in which case it displays that printable character.  How do I get it to force hex for all bytes?  Thanks, Steve
> 
> | 
> 
> | Is this what you want?
> 
> | 
> 
> | >>> ''.join('%02x' % x for x in b'hello world')
> 
> | '68656c6c6f20776f726c64'
> 
> 
> 
> Not to forget binascii.hexlify.
> 
> -- 
> 
> Cameron Simpson <cs at zip.com.au>
> 
> 
> 
> Every particle continues in its state of rest or uniform motion in a straight
> 
> line except insofar as it doesn't.      - Sir Arther Eddington

Thanks for the binascii.hexlify tip. I was able to make it work but I did have to write a function to get it exactly the string I wanted.  I wanted, for example, <b'\n\x00'> to display as <0x0A 0x00> or <b'!\xff(\xc0'> to display as <0x21 0xFF 0x28 0xC0>.  



From wxjmfauth at gmail.com  Fri May 31 03:51:55 2013
From: wxjmfauth at gmail.com (jmfauth)
Date: Fri, 31 May 2013 00:51:55 -0700 (PDT)
Subject: python b'...' notation
References: <CALwzid=mdbD5n2-08uAsD5eRub3FadEOBYVS4NWmCQy7W+-XXQ@mail.gmail.com>
	<mailman.2384.1369866008.3114.python-list@python.org>
	<94eb93eb-3f95-448c-979a-5bfc4da9ef06@googlegroups.com>
Message-ID: <bf0cc4f9-5535-4174-b0e3-e265701c0e9b@k3g2000vbn.googlegroups.com>

On 31 mai, 00:19, alcyon <st... at terrafirma.us> wrote:
> On Wednesday, May 29, 2013 3:19:42 PM UTC-7, Cameron Simpson wrote:
> > On 29May2013 13:14, Ian Kelly <ian.g.ke... at gmail.com> wrote:
>
> > | On Wed, May 29, 2013 at 12:33 PM, alcyon <st... at terrafirma.us> wrote:
>
> > | > This notation displays hex values except when they are 'printable', in which case it displays that printable character. ?How do I get it to force hex for all bytes? ?Thanks, Steve
>
> > |
>
> > | Is this what you want?
>
> > |
>
> > | >>> ''.join('%02x' % x for x in b'hello world')
>
> > | '68656c6c6f20776f726c64'
>
> > Not to forget binascii.hexlify.
>
> > --
>
> > Cameron Simpson <c... at zip.com.au>
>
> > Every particle continues in its state of rest or uniform motion in a straight
>
> > line except insofar as it doesn't. ? ? ?- Sir Arther Eddington
>
> Thanks for the binascii.hexlify tip. I was able to make it work but I did have to write a function to get it exactly the string I wanted. ?I wanted, for example, <b'\n\x00'> to display as <0x0A 0x00> or <b'!\xff(\xc0'> to display as <0x21 0xFF 0x28 0xC0>.

--------

>>> a = b'!\xff(\xc0\n\x00'
>>> z = ['0x{:02X}'.format(c) for c in b]
>>> z
['0x21', '0xFF', '0x28', '0xC0', '0x0A', '0x00']
>>> s = ' '.join(z)
>>> s
'0x21 0xFF 0x28 0xC0 0x0A 0x00'
>>>

jmf



From damage3025 at gmail.com  Wed May 29 14:13:23 2013
From: damage3025 at gmail.com (Ma Xiaojun)
Date: Thu, 30 May 2013 02:13:23 +0800
Subject: How clean/elegant is Python's syntax?
Message-ID: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>

Hi, list.

I hope this is not a duplicate of older question. If so, drop me a
link is enough.

I've used Python here and there, just for the sweet libraries though.

For the core language, I have mixed feeling. On one hand, I find that
Python has some sweet feature that is quite useful. On the other hand,
I often find Pyhton snippets around hard to understand. I admit that I
never learned Python very formally; I've programmed in many other
languages already.

Code snippets in BASIC or Pascal seems quite obvious to understand
(Unless I don't understand the algorithm) .

Can someone inspire me?


From damage3025 at gmail.com  Wed May 29 14:37:35 2013
From: damage3025 at gmail.com (Ma Xiaojun)
Date: Thu, 30 May 2013 02:37:35 +0800
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
Message-ID: <CAGVx7UXHfdMSL18q1bz4OWyz_rYirogJa7++VarBfDSd0BReQw@mail.gmail.com>

A bit more context.

If visiting z.cn (Amazon China), one can see that there are plenty of
new (published in 2010 or later) books on QBASIC, Visual Basic, Visual
Foxpro.

This is weird, if one want to do development legally these tools won't
be a option for new programmers.

However, I also like to know whether there are any technical arguments
that Python is superior in the context of education.

For pure procedural paradigm, I haven't seen much advantages of Python.
Yes, Python has true OOP but I don't like this argument since I don't
like Java-ism true OOP.
Yes, Python has much more libraries. But it seems that Python is more
useful and suitable in CLI and Web applications. People are still
discussing whether to replace tkinter with wxPython or not. VB and VFP
people are never bothered with such issue.


From rosuav at gmail.com  Wed May 29 14:54:44 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 04:54:44 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAGVx7UXHfdMSL18q1bz4OWyz_rYirogJa7++VarBfDSd0BReQw@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGVx7UXHfdMSL18q1bz4OWyz_rYirogJa7++VarBfDSd0BReQw@mail.gmail.com>
Message-ID: <CAPTjJmrCU+Em0vVJnhipEWiMEreEcnV1YHxZYpw+T_srEQ-G=A@mail.gmail.com>

On Thu, May 30, 2013 at 4:37 AM, Ma Xiaojun <damage3025 at gmail.com> wrote:
> Yes, Python has much more libraries. But it seems that Python is more
> useful and suitable in CLI and Web applications. People are still
> discussing whether to replace tkinter with wxPython or not. VB and VFP
> people are never bothered with such issue.

Let me put this debate in context by giving an analogous example. A
while back, it was loudly proclaimed that it was far easier to write
iPhone apps than Android ones, because Android apps had to worry about
a variety of different screen resolutions/sizes, while iPhone ones
could be certain of what they were going to get. But what this really
meant was that writing for iPhone was equivalent to writing for
"Android on phone model XYZ", and that you could, by targeting
Android, also then make your app available on a bunch of other phone
models by simply dealing with the differences.

Python gives you a lot more choice than VB does. With Visual BASIC, if
you don't like the windowing toolkit, tough. You don't have any
alternative. With Python, you can pretend it's like VB by simply
picking one toolkit and ignoring all the others; it'll be exactly the
same. But the benefit is that, if you decide you want one of the
others, it's relatively cheap to switch.

That said, though, GUIs and databasing are two of the areas where I
think Python's standard library could stand to be improved a bit.
There are definitely some rough edges there.

ChrisA


From walterhurry at lavabit.com  Wed May 29 17:01:34 2013
From: walterhurry at lavabit.com (Walter Hurry)
Date: Wed, 29 May 2013 21:01:34 +0000 (UTC)
Subject: How clean/elegant is Python's syntax?
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGVx7UXHfdMSL18q1bz4OWyz_rYirogJa7++VarBfDSd0BReQw@mail.gmail.com>
	<mailman.2376.1369853687.3114.python-list@python.org>
Message-ID: <ko5qbe$816$1@news.albasani.net>

On Thu, 30 May 2013 04:54:44 +1000, Chris Angelico wrote:

<snip>
> GUIs and databasing are two of the areas where I
> think Python's standard library could stand to be improved a bit.
> There are definitely some rough edges there.

Dunno what you mean about "standard library", but I'm very happy with 
wxPython and psycopg2 for GUIs and databasing respectively.



From rosuav at gmail.com  Wed May 29 23:57:49 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 13:57:49 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <ko5qbe$816$1@news.albasani.net>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGVx7UXHfdMSL18q1bz4OWyz_rYirogJa7++VarBfDSd0BReQw@mail.gmail.com>
	<mailman.2376.1369853687.3114.python-list@python.org>
	<ko5qbe$816$1@news.albasani.net>
Message-ID: <CAPTjJmqQSdx=PW2KJGyE++EFDwO2+QT4Tac1dSXjMVwWxr702g@mail.gmail.com>

On Thu, May 30, 2013 at 7:01 AM, Walter Hurry <walterhurry at lavabit.com> wrote:
> On Thu, 30 May 2013 04:54:44 +1000, Chris Angelico wrote:
>
> <snip>
>> GUIs and databasing are two of the areas where I
>> think Python's standard library could stand to be improved a bit.
>> There are definitely some rough edges there.
>
> Dunno what you mean about "standard library", but I'm very happy with
> wxPython and psycopg2 for GUIs and databasing respectively.

They are not part of the standard library. Yes, Python is strongly
enhanced by additional packages off PyPI, but that's not the same
thing; if I publish a program that requires psycopg2, I can't simply
say "go get Python from your OS's repository or python.org", I have to
also instruct people to install another package. On Debian, I can
simply apt-get python-psycopg2, which I would trust to be (a) a stable
build, (b) compatible with the apt-gettable python (which is 2.7.3;
ditto python3-psycopg2 and python3, for 3.2.3), and (c) from an
authoritative source. There's probably a way to do this for other
Linuxes too, but I don't know the exact package names everywhere. And
on Windows, I have no idea what the best way would be.

These days, networking is considered essential. Python's standard
library includes basic sockets, HTTP (client and server), etc. AFAIK
Python doesn't have obscurities like DNS (obviously you can connect a
socket by hostname, but you can't look up an SPF record, nor can you
write a DNS server), but networking generally is considered important
enough to be inbuilt. Why is databasing second-class?

ChrisA


From dreamingforward at gmail.com  Wed May 29 17:13:12 2013
From: dreamingforward at gmail.com (Mark Janssen)
Date: Wed, 29 May 2013 14:13:12 -0700
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAGVx7UXHfdMSL18q1bz4OWyz_rYirogJa7++VarBfDSd0BReQw@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGVx7UXHfdMSL18q1bz4OWyz_rYirogJa7++VarBfDSd0BReQw@mail.gmail.com>
Message-ID: <CAMjeLr8YUhyAj-iFcA1U+KUGYwRRUz3=r9oS-zikzWyO2Z+YyA@mail.gmail.com>

You might try http://wiki.python.org/moin/BeginnersGuide

-- 
MarkJ
Tacoma, Washington


From cs at zip.com.au  Wed May 29 18:12:07 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Thu, 30 May 2013 08:12:07 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
Message-ID: <20130529221207.GA44756@cskk.homeip.net>

On 30May2013 02:13, Ma Xiaojun <damage3025 at gmail.com> wrote:
| For the core language, I have mixed feeling. On one hand, I find that
| Python has some sweet feature that is quite useful. On the other hand,
| I often find Pyhton snippets around hard to understand.

I think you will find that is lack of practice. I find Python far
far easier to read, even in snippet form. BUT, for years I found
it obtuse because I hadn't learnt it. Now that I have, I rarely
want to use other things (if Python is apt; often but not always).

| I admit that I
| never learned Python very formally; I've programmed in many other
| languages already.

Me too. Use it some more.

| Code snippets in BASIC or Pascal seems quite obvious to understand
| (Unless I don't understand the algorithm) .

Code in BASIC is generally lower level than python; it is less
expressive.  Because of this, it will be more obvious in terms of
being more direct. But it will be less expressive because you will
often need more BASIC to do something than you would with Python.
So python is usually more succinct, and therefore more more expressive:
a shorter but very readable way to do the same thing.

Comparison: your English is excellent. Presuming from context that
you're in China, many of your compatriots do not speak fluent English
(and why should they?) For those speaking English as a second
language there are difficulties; English grammar I gather is very
different, and it has a fine suite of irregular forms. (Let me say
up front that I do not speak Chinese at all.)

Anyway, would you rather converse with someone fluent, or not? I
would expect you would far rather deal with a fluent English speaker
or a fluent Chinese speaker than a speaker using English badly.

Python code is a lot like written English. BASIC is like badly
written English.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

Helicopters are considerably more expensive [than fixed wing aircraft],
which is only right because they don't actually fly, but just beat
the air into submission.        - Paul Tomblin


From drsalists at gmail.com  Wed May 29 20:24:48 2013
From: drsalists at gmail.com (Dan Stromberg)
Date: Wed, 29 May 2013 17:24:48 -0700
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
Message-ID: <CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>

On Wed, May 29, 2013 at 11:13 AM, Ma Xiaojun <damage3025 at gmail.com> wrote:

> Hi, list.
>
> For the core language, I have mixed feeling. On one hand, I find that
> Python has some sweet feature that is quite useful. On the other hand,
> I often find Pyhton snippets around hard to understand. I admit that I
> never learned Python very formally; I've programmed in many other
> languages already.
>
> Code snippets in BASIC or Pascal seems quite obvious to understand
> (Unless I don't understand the algorithm) .
>

I'm finding it kind of hard to imagine not finding Python's syntax and
semantics pretty graceful.

About the only thing I don't like is:

   var = 1,

That binds var to a tuple (singleton) value, instead of 1.

Oh, and method decorators seem much more complex than they should've been.

But on the whole, python is a pretty beautiful language.  It's not just
another rehash of Pascal though; if that's what you want you might be
better off looking elsewhere.
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From damage3025 at gmail.com  Wed May 29 21:14:06 2013
From: damage3025 at gmail.com (Ma Xiaojun)
Date: Thu, 30 May 2013 09:14:06 +0800
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
Message-ID: <CAGVx7UV1GcTBc91w_=cm8OFYzAfJTAb7pyo6=9pccJQwkWkYzQ@mail.gmail.com>

On Thu, May 30, 2013 at 8:24 AM, Dan Stromberg <drsalists at gmail.com> wrote:
> I'm finding it kind of hard to imagine not finding Python's syntax and
> semantics pretty graceful.
>
> About the only thing I don't like is:
>
>    var = 1,
>
> That binds var to a tuple (singleton) value, instead of 1.
>
> Oh, and method decorators seem much more complex than they should've been.

Yes, you touched something. IMHO, Python has far more built-in
features so it looks at least complicated from time to time.

For example, some people use "generating 9x9 multiplication table" as
an programming exercise.

What interest me is a one liner:
print '\n'.join(['\t'.join(['%d*%d=%d' % (j,i,i*j) for i in
range(1,10)]) for j in range(1,10)])

I don't like code like this. But Python at least allow such practise.

> But on the whole, python is a pretty beautiful language.  It's not just
> another rehash of Pascal though; if that's what you want you might be better
> off looking elsewhere.

That's a fair point.


From rustompmody at gmail.com  Wed May 29 22:49:19 2013
From: rustompmody at gmail.com (rusi)
Date: Wed, 29 May 2013 19:49:19 -0700 (PDT)
Subject: How clean/elegant is Python's syntax?
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
Message-ID: <851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>

On May 30, 6:14?am, Ma Xiaojun <damage3... at gmail.com> wrote:
> What interest me is a one liner:
> print '\n'.join(['\t'.join(['%d*%d=%d' % (j,i,i*j) for i in
> range(1,10)]) for j in range(1,10)])

Ha,Ha! The join method is one of the (for me) ugly features of python.
You can sweep it under the carpet with a one-line join function and
then write clean and pretty code:

#joinwith
def joinw(l,sep): return sep.join(l)

def mktable(m,n):
    return [[(j,i,i*j) for i in range(1,m+1)] for j in range(1,n+1)]

def prettyrow(r):
    return joinw(['%d*%d=%d' % ele for ele in r],'\t')

def prettytable(t):
    return joinw([prettyrow(r) for r in t],'\n')

> I don't like code like this. But Python at least allow such practise.

Are you saying VB etc disallow dirty code??  Dirty code is always
possible in all languages. Of course the shape and size and smell of
the dirt will differ


From ian.g.kelly at gmail.com  Thu May 30 14:36:54 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 30 May 2013 12:36:54 -0600
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
	<851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
Message-ID: <CALwzidkvPJFWh1csV+sC6mFb9bZFaft_T5e+5E49eHucBTf-hQ@mail.gmail.com>

On Wed, May 29, 2013 at 8:49 PM, rusi <rustompmody at gmail.com> wrote:
> On May 30, 6:14 am, Ma Xiaojun <damage3... at gmail.com> wrote:
>> What interest me is a one liner:
>> print '\n'.join(['\t'.join(['%d*%d=%d' % (j,i,i*j) for i in
>> range(1,10)]) for j in range(1,10)])
>
> Ha,Ha! The join method is one of the (for me) ugly features of python.
> You can sweep it under the carpet with a one-line join function and
> then write clean and pretty code:
>
> #joinwith
> def joinw(l,sep): return sep.join(l)

I don't object to changing the join method (one of the more
shoe-horned string methods) back into a function, but to my eyes
you've got the arguments backward.  It should be:

def join(sep, iterable): return sep.join(iterable)

Putting the separator first feels more natural to me because I expect
the separator to usually be short as compared to the iterable, which
is often a longer expression (as is the case in both of your
subsequent usages).  Placing the separator first also preserves
consistency of interface with the str.join and bytes.join functions,
as well as the older string.join function.


From rosuav at gmail.com  Thu May 30 14:44:42 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 04:44:42 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CALwzidkvPJFWh1csV+sC6mFb9bZFaft_T5e+5E49eHucBTf-hQ@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
	<851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
	<CALwzidkvPJFWh1csV+sC6mFb9bZFaft_T5e+5E49eHucBTf-hQ@mail.gmail.com>
Message-ID: <CAPTjJmqHE_Ctyn5dEL3TeXaan4_cF9JUWHi_hMb2nyafhpn5CQ@mail.gmail.com>

On Fri, May 31, 2013 at 4:36 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Wed, May 29, 2013 at 8:49 PM, rusi <rustompmody at gmail.com> wrote:
>> On May 30, 6:14 am, Ma Xiaojun <damage3... at gmail.com> wrote:
>>> What interest me is a one liner:
>>> print '\n'.join(['\t'.join(['%d*%d=%d' % (j,i,i*j) for i in
>>> range(1,10)]) for j in range(1,10)])
>>
>> Ha,Ha! The join method is one of the (for me) ugly features of python.
>> You can sweep it under the carpet with a one-line join function and
>> then write clean and pretty code:
>>
>> #joinwith
>> def joinw(l,sep): return sep.join(l)
>
> I don't object to changing the join method (one of the more
> shoe-horned string methods) back into a function, but to my eyes
> you've got the arguments backward.  It should be:
>
> def join(sep, iterable): return sep.join(iterable)

Trouble is, it makes some sense either way. I often put the larger
argument first - for instance, I would write 123412341324*5 rather
than the other way around - and in this instance, it hardly seems as
clear-cut as you imply. But the function can't be written to take them
in either order, because strings are iterable too. (And functions that
take args either way around aren't better than those that make a
decision.)

ChrisA


From ian.g.kelly at gmail.com  Thu May 30 14:51:14 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 30 May 2013 12:51:14 -0600
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAPTjJmqHE_Ctyn5dEL3TeXaan4_cF9JUWHi_hMb2nyafhpn5CQ@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
	<851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
	<CALwzidkvPJFWh1csV+sC6mFb9bZFaft_T5e+5E49eHucBTf-hQ@mail.gmail.com>
	<CAPTjJmqHE_Ctyn5dEL3TeXaan4_cF9JUWHi_hMb2nyafhpn5CQ@mail.gmail.com>
Message-ID: <CALwzid=Y9gWBOjEHeE=M6q8Gx0bW=qqR15AeVg+nQf8E0_KEEg@mail.gmail.com>

On Thu, May 30, 2013 at 12:44 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Fri, May 31, 2013 at 4:36 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>> I don't object to changing the join method (one of the more
>> shoe-horned string methods) back into a function, but to my eyes
>> you've got the arguments backward.  It should be:
>>
>> def join(sep, iterable): return sep.join(iterable)
>
> Trouble is, it makes some sense either way. I often put the larger
> argument first - for instance, I would write 123412341324*5 rather
> than the other way around - and in this instance, it hardly seems as
> clear-cut as you imply. But the function can't be written to take them
> in either order, because strings are iterable too. (And functions that
> take args either way around aren't better than those that make a
> decision.)

The reason I like having the shorter argument first (at least for
function calls) is for when I'm reading the code.  If I'm interested
in the second argument, then to find it I have to scan over the first
argument.  I would rather scan over something short like '\n' than
something longer like a list comprehension.  It sounds like a trivial
thing, but it really does make it easier to find where an expression
starts and ends when the expression is short.


From rosuav at gmail.com  Thu May 30 17:28:17 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 07:28:17 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CALwzid=Y9gWBOjEHeE=M6q8Gx0bW=qqR15AeVg+nQf8E0_KEEg@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
	<851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
	<CALwzidkvPJFWh1csV+sC6mFb9bZFaft_T5e+5E49eHucBTf-hQ@mail.gmail.com>
	<CAPTjJmqHE_Ctyn5dEL3TeXaan4_cF9JUWHi_hMb2nyafhpn5CQ@mail.gmail.com>
	<CALwzid=Y9gWBOjEHeE=M6q8Gx0bW=qqR15AeVg+nQf8E0_KEEg@mail.gmail.com>
Message-ID: <CAPTjJmp37Wtm5Czc+PiSYPfg57wCRohhDXdej0qxQ-rHgHE1GQ@mail.gmail.com>

On Fri, May 31, 2013 at 4:51 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Thu, May 30, 2013 at 12:44 PM, Chris Angelico <rosuav at gmail.com> wrote:
>> On Fri, May 31, 2013 at 4:36 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>>> I don't object to changing the join method (one of the more
>>> shoe-horned string methods) back into a function, but to my eyes
>>> you've got the arguments backward.  It should be:
>>>
>>> def join(sep, iterable): return sep.join(iterable)
>>
>> Trouble is, it makes some sense either way. I often put the larger
>> argument first - for instance, I would write 123412341324*5 rather
>> than the other way around - and in this instance, it hardly seems as
>> clear-cut as you imply. But the function can't be written to take them
>> in either order, because strings are iterable too. (And functions that
>> take args either way around aren't better than those that make a
>> decision.)
>
> The reason I like having the shorter argument first (at least for
> function calls) is for when I'm reading the code.  If I'm interested
> in the second argument, then to find it I have to scan over the first
> argument.  I would rather scan over something short like '\n' than
> something longer like a list comprehension.  It sounds like a trivial
> thing, but it really does make it easier to find where an expression
> starts and ends when the expression is short.

Yes, I do agree with that argument. But there's more to picking
argument order than simply "sort by predicted length" :) I'm not
saying it's *wrong* to put sep first, just that it's not as
clearly-and-obviously-the-one-right-way as you suggested.

ChrisA


From python at mrabarnett.plus.com  Thu May 30 15:38:40 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 30 May 2013 20:38:40 +0100
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAPTjJmqHE_Ctyn5dEL3TeXaan4_cF9JUWHi_hMb2nyafhpn5CQ@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
	<851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
	<CALwzidkvPJFWh1csV+sC6mFb9bZFaft_T5e+5E49eHucBTf-hQ@mail.gmail.com>
	<CAPTjJmqHE_Ctyn5dEL3TeXaan4_cF9JUWHi_hMb2nyafhpn5CQ@mail.gmail.com>
Message-ID: <51A7AAC0.6080509@mrabarnett.plus.com>

On 30/05/2013 19:44, Chris Angelico wrote:
> On Fri, May 31, 2013 at 4:36 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>> On Wed, May 29, 2013 at 8:49 PM, rusi <rustompmody at gmail.com> wrote:
>>> On May 30, 6:14 am, Ma Xiaojun <damage3... at gmail.com> wrote:
>>>> What interest me is a one liner:
>>>> print '\n'.join(['\t'.join(['%d*%d=%d' % (j,i,i*j) for i in
>>>> range(1,10)]) for j in range(1,10)])
>>>
>>> Ha,Ha! The join method is one of the (for me) ugly features of python.
>>> You can sweep it under the carpet with a one-line join function and
>>> then write clean and pretty code:
>>>
>>> #joinwith
>>> def joinw(l,sep): return sep.join(l)
>>
>> I don't object to changing the join method (one of the more
>> shoe-horned string methods) back into a function, but to my eyes
>> you've got the arguments backward.  It should be:
>>
>> def join(sep, iterable): return sep.join(iterable)
>
> Trouble is, it makes some sense either way. I often put the larger
> argument first - for instance, I would write 123412341324*5 rather
> than the other way around - and in this instance, it hardly seems as
> clear-cut as you imply. But the function can't be written to take them
> in either order, because strings are iterable too. (And functions that
> take args either way around aren't better than those that make a
> decision.)
>
And additional argument (pun not intended) for putting sep second is
that you can give it a default value:

    def join(iterable, sep=""): return sep.join(iterable)



From ian.g.kelly at gmail.com  Fri May 31 11:43:54 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 31 May 2013 09:43:54 -0600
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <51A7AAC0.6080509@mrabarnett.plus.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
	<851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
	<CALwzidkvPJFWh1csV+sC6mFb9bZFaft_T5e+5E49eHucBTf-hQ@mail.gmail.com>
	<CAPTjJmqHE_Ctyn5dEL3TeXaan4_cF9JUWHi_hMb2nyafhpn5CQ@mail.gmail.com>
	<51A7AAC0.6080509@mrabarnett.plus.com>
Message-ID: <CALwzid=kRrojg6B6uy_PYiYrcm9tsGbKZrSF7eMuGOt89UFJTQ@mail.gmail.com>

On Thu, May 30, 2013 at 1:38 PM, MRAB <python at mrabarnett.plus.com> wrote:
> And additional argument (pun not intended) for putting sep second is
> that you can give it a default value:
>
>    def join(iterable, sep=""): return sep.join(iterable)

One argument against the default is that it is specific to the str
type.  If you then tried to use join with an iterable of bytes objects
and the default sep argument, you would get a TypeError.  At least not
having the default forces you to be explicit about which string type
you're joining.


From rosuav at gmail.com  Fri May 31 14:52:53 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 1 Jun 2013 04:52:53 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CALwzid=kRrojg6B6uy_PYiYrcm9tsGbKZrSF7eMuGOt89UFJTQ@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
	<851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
	<CALwzidkvPJFWh1csV+sC6mFb9bZFaft_T5e+5E49eHucBTf-hQ@mail.gmail.com>
	<CAPTjJmqHE_Ctyn5dEL3TeXaan4_cF9JUWHi_hMb2nyafhpn5CQ@mail.gmail.com>
	<51A7AAC0.6080509@mrabarnett.plus.com>
	<CALwzid=kRrojg6B6uy_PYiYrcm9tsGbKZrSF7eMuGOt89UFJTQ@mail.gmail.com>
Message-ID: <CAPTjJmqzGnosfz_wJDaWpAjAfZcrOU2Gnpnv97Hy8KkvkUkxAw@mail.gmail.com>

On Sat, Jun 1, 2013 at 1:43 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Thu, May 30, 2013 at 1:38 PM, MRAB <python at mrabarnett.plus.com> wrote:
>> And additional argument (pun not intended) for putting sep second is
>> that you can give it a default value:
>>
>>    def join(iterable, sep=""): return sep.join(iterable)
>
> One argument against the default is that it is specific to the str
> type.  If you then tried to use join with an iterable of bytes objects
> and the default sep argument, you would get a TypeError.  At least not
> having the default forces you to be explicit about which string type
> you're joining.

What about:

def join(iterable, sep=None):
    if sep is not None: return sep.join(iterable)
    iterable=iter(iterable)
    first = next(iterable)
    return first + type(first)().join(iterable)

Granted, it has some odd error messages if you pass it stuff that isn't strings:

>>> join([[1,2,3],[4,5,6]])
Traceback (most recent call last):
  File "<pyshell#241>", line 1, in <module>
    join([[1,2,3],[4,5,6]])
  File "<pyshell#235>", line 5, in join
    return first + type(first)().join(iterable)
AttributeError: 'list' object has no attribute 'join'

but you'd get that sort of thing anyway.

(NOTE: I am *not* advocating this. I just see it as a solution to one
particular objection.)

ChrisA


From rustompmody at gmail.com  Thu May 30 14:47:00 2013
From: rustompmody at gmail.com (rusi)
Date: Thu, 30 May 2013 11:47:00 -0700 (PDT)
Subject: How clean/elegant is Python's syntax?
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
	<851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
	<mailman.2443.1369939057.3114.python-list@python.org>
Message-ID: <0debce7e-f05c-40c4-b688-737e7ad49a40@z10g2000pbn.googlegroups.com>

On May 30, 11:36?pm, Ian Kelly <ian.g.ke... at gmail.com> wrote:
> On Wed, May 29, 2013 at 8:49 PM, rusi <rustompm... at gmail.com> wrote:
> > On May 30, 6:14 am, Ma Xiaojun <damage3... at gmail.com> wrote:
> >> What interest me is a one liner:
> >> print '\n'.join(['\t'.join(['%d*%d=%d' % (j,i,i*j) for i in
> >> range(1,10)]) for j in range(1,10)])
>
> > Ha,Ha! The join method is one of the (for me) ugly features of python.
> > You can sweep it under the carpet with a one-line join function and
> > then write clean and pretty code:
>
> > #joinwith
> > def joinw(l,sep): return sep.join(l)
>
> I don't object to changing the join method (one of the more
> shoe-horned string methods) back into a function, but to my eyes
> you've got the arguments backward. ?It should be:
>
> def join(sep, iterable): return sep.join(iterable)
>
> Putting the separator first feels more natural to me because I expect
> the separator to usually be short as compared to the iterable, which
> is often a longer expression (as is the case in both of your
> subsequent usages). ?Placing the separator first also preserves
> consistency of interface with the str.join and bytes.join functions,
> as well as the older string.join function.

This is a subjective view of course...
My problem is not method vs function but the order.
Ive seen/used join dozens of times. Yet I find
"".join(["apple","bear","cat"])
backkwards as compared to
["apple","bear","cat"].join("")

The consistency is a separate question -- not arguing about that. Just
that I dont like the look


From john_ladasky at sbcglobal.net  Thu May 30 18:01:20 2013
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Thu, 30 May 2013 15:01:20 -0700 (PDT)
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <mailman.2443.1369939057.3114.python-list@python.org>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
	<mailman.2389.1369876474.3114.python-list@python.org>
	<851ce96a-0223-42b0-8d99-902294c71f58@hc4g2000pbb.googlegroups.com>
	<mailman.2443.1369939057.3114.python-list@python.org>
Message-ID: <32d47a30-8b74-41f4-a774-c878c60c7f73@googlegroups.com>

On Thursday, May 30, 2013 11:36:54 AM UTC-7, Ian wrote:

> I don't object to changing the join method (one of the more 
> shoe-horned string methods) back into a function, but to my eyes
> you've got the arguments backward.  It should be:
>
> def join(sep, iterable): return sep.join(iterable)
> 
> Putting the separator first feels more natural to me because I expect
> the separator to usually be short as compared to the iterable, which
> is often a longer expression (as is the case in both of your
> subsequent usages).  Placing the separator first also preserves 
> consistency of interface with the str.join and bytes.join functions,
> as well as the older string.join function.

That may all be true, but the join() function shown will return a sequence starting with iterable[0] (followed by sep, and then iterable[1], then sep, etc.).  I find it more natural to see iterable as the first argument passed to join() for that reason.  Season to taste, I guess.


From rosuav at gmail.com  Wed May 29 23:59:08 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 13:59:08 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<CAGGBd_oT=vqvPGZy+d1H=XHjdPCmYUxJMXAwii7WH845xrYybQ@mail.gmail.com>
Message-ID: <CAPTjJmpVzQA4AcsO3pEMyOsKGZ3BcKxd3XgK+Gz4Pq1MeYZ=MA@mail.gmail.com>

On Thu, May 30, 2013 at 10:24 AM, Dan Stromberg <drsalists at gmail.com> wrote:
> I'm finding it kind of hard to imagine not finding Python's syntax and
> semantics pretty graceful.
>
> About the only thing I don't like is:
>
>    var = 1,
>
> That binds var to a tuple (singleton) value, instead of 1.

I agree, and would write it as:

var = (1,)

for clarity.

ChrisA


From steve+comp.lang.python at pearwood.info  Thu May 30 02:18:43 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 06:18:43 GMT
Subject: How clean/elegant is Python's syntax?
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
Message-ID: <51a6ef42$0$11118$c3e8da3@news.astraweb.com>

On Thu, 30 May 2013 02:37:35 +0800, Ma Xiaojun wrote:


> For pure procedural paradigm, I haven't seen much advantages of Python.

Nice syntax with a minimum of boiler plate -- "executable pseudo-code", 
as they say. Extensive library support -- "batteries included". These are 
both good advantages.


> Yes, Python has true OOP but I don't like this argument since I don't
> like Java-ism true OOP.

Java is not the best example of OOP. In some ways, it is a terrible 
example of OOP: some values are not objects, classes are not first-class 
values, and the language is horribly verbose. There are good reasons for 
some of these things, but good reasons or bad, Java is *not* the exemplar 
of OOP that some Java coders believe.

In some ways, Python is a more pure OOP language than Java: everything in 
Python is an object, including classes themselves.

In other ways, Python is a less pure and more practical language. You 
don't have to wrap every piece of functionality in a class. Python 
encourages you to write mixed procedural, functional and object oriented 
code, whatever is best for the problem you are trying to solve, which is 
very much in contrast to Java:

http://steve-yegge.blogspot.com.au/2006/03/execution-in-kingdom-of-
nouns.html


> Yes, Python has much more libraries. But it seems that Python is more
> useful and suitable in CLI and Web applications. 

That is fair. All languages have their strengths and weaknesses. I 
wouldn't use Python to program low-level device driver code, and I 
wouldn't write a web-app in C.


> People are still
> discussing whether to replace tkinter with wxPython or not. VB and VFP
> people are never bothered with such issue.

Which people? "People" can discuss any rubbish they like. For many 
reasons, tkinter will not be replaced. For the standard library, it is a 
good, stable, powerful but not cutting-edge GUI library. If you don't 
like it, you can install a third-party framework like wxPython. Using 
tkinter is not compulsory.

In the case of VB and VFP, they aren't bothered by such issues because 
they're used to closed-source, proprietary programming where you use what 
you are given and like it. In the open-source world, if you don't like 
what you are given, you find something else, and if you can't find it, 
you make it yourself.



-- 
Steven


From damage3025 at gmail.com  Thu May 30 04:54:14 2013
From: damage3025 at gmail.com (Ma Xiaojun)
Date: Thu, 30 May 2013 16:54:14 +0800
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <51a6ef42$0$11118$c3e8da3@news.astraweb.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
Message-ID: <CAGVx7UXPeJpuCNg0w1jFUz_A1xuSsfGzrX9p19Ke5yVcFkvaNw@mail.gmail.com>

On Thu, May 30, 2013 at 2:18 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Which people? "People" can discuss any rubbish they like. For many
> reasons, tkinter will not be replaced. For the standard library, it is a
> good, stable, powerful but not cutting-edge GUI library. If you don't
> like it, you can install a third-party framework like wxPython. Using
> tkinter is not compulsory.

I'm new to tkinter and find tkdocs.com seems quite good.
But tkdocs.com's Python code sample is in Python 3.
And wxPython doesn't support Python 3 yet.
( May not be big issue but it's kind of bad. )

I observation about tkinter is that it seems lack of sophisticated features.
For example, there is nothing like DataWindow in PowerBuilder?

Python's IDLE is written in tkinter.
But anyone willing to use IDLE is a successful example of tkinter?
I actually use Gedit more than PyDev, etc.
But the non-fancy state of IDLE does reflect something, I guess.

> In the case of VB and VFP, they aren't bothered by such issues because
> they're used to closed-source, proprietary programming where you use what
> you are given and like it. In the open-source world, if you don't like
> what you are given, you find something else, and if you can't find it,
> you make it yourself.

I doesn't mean that choices are bad. I just kind of doubt that whether
Python with a open source GUI toolkit can cover the features provided
by VB standard controls and some external Windows built-in controls.
I'm almost sure that tkinter lacks the features provided by
sophisticated controls.
I have limited knowledge to VFP.


From rustompmody at gmail.com  Thu May 30 13:12:22 2013
From: rustompmody at gmail.com (rusi)
Date: Thu, 30 May 2013 10:12:22 -0700 (PDT)
Subject: How clean/elegant is Python's syntax?
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2397.1369904083.3114.python-list@python.org>
Message-ID: <503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>

On Thu, May 30, 2013 at 9:34 AM, Ma Xiaojun <damage3025 at gmail.com>
wrote:
>
> On Thu, May 30, 2013 at 10:49 AM, rusi <rustompmody at gmail.com> wrote:
> > Ha,Ha! The join method is one of the (for me) ugly features of python.
> > You can sweep it under the carpet with a one-line join function and
> > then write clean and pretty code:
> >
> > #joinwith
> > def joinw(l,sep): return sep.join(l)
> >
> > def mktable(m,n):
> >     return [[(j,i,i*j) for i in range(1,m+1)] for j in range(1,n+1)]
> >
> > def prettyrow(r):
> >     return joinw(['%d*%d=%d' % ele for ele in r],'\t')
> >
> > def prettytable(t):
> >     return joinw([prettyrow(r) for r in t],'\n')
>
> Wait a minute! Isn't the most nature way of doing/thinking "generating
> 9x9 multiplication table" two nested loop?

Thats like saying that the most natur(al) way of using a car is to
attach a horse to it.
Sure if all you've seen are horse-carriages then a horseless carriage
will seem nonsensical.  Once you get used to horseless carriages the
horsed ones would seem quite a nuisance [global warming aside!!]

The only problem with this analogy is that you have to imagine the
world of horse/horseless 'cars' in 1900 and not 2013.

Likewise in the world of programming, 90% of programmers think
imperative/OO programming is natural while functional programming is
strange.  Just wait 10 years and see if things are not drastically
different!

>
> I understand that using "join", we don't need to worry about "one
> element doesn't need white space" issue. And that's it.

More evidence of the above!
join like list-comprehensions are tools for functional programming and
not merely ways of writing loops in short.

The key difference between the two is seen not in the code you write
but in the natural language (English) you use to describe it:

> Wait a minute! Isn't the most nature way of doing/thinking "generating
> 9x9 multiplication table" two nested loop?

You associate the primal (f)act of thinking about programming with
*doing* the generating.
By contrast the functional programmer thinks about what *is* the
result.

Please also note the difference in emphasis in your code and mine.
Rewriting to make it more obvious:

# The main multiplication table building function
def multtable(m,n):
    return [[(j,i,i*j) for i in range(1,m+1)] for j in range(1,n+1)]

# The 'icing' to get it into the shape you want
def joinw(l,sep): return sep.join(l)
def prettytable(t):
    return joinw([joinw(['%d*%d=%d' % ele for ele in r],'\t') for r in
t],'\n')

The call that puts them together:
>>> print prettytable(multtable(6,7))

The nice thing about the last is that it separates three things:
1. Computing the actual table
2. The string form of that table that looks the way we want
3. Printing that string

And I can see each of these separately:

In [2]: multtable(2,3)
Out[2]: [[(1, 1, 1), (1, 2, 2)], [(2, 1, 2), (2, 2, 4)], [(3, 1, 3),
(3, 2, 6)]]

In [3]: prettytable(_)
Out[3]: '1*1=1\t1*2=2\n2*1=2\t2*2=4\n3*1=3\t3*2=6'

In [4]: print _
1*1=1	1*2=2
2*1=2	2*2=4
3*1=3	3*2=6

-------------------
I would be pleasantly surprised if the double nested loop you think
natural, allowed for such a modular separation!


From rosuav at gmail.com  Thu May 30 13:28:10 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 03:28:10 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2397.1369904083.3114.python-list@python.org>
	<503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>
Message-ID: <CAPTjJmp=5radGce2qEUHRvw1VTk51aj1b6rwgP8fa7BGGrN3aA@mail.gmail.com>

On Fri, May 31, 2013 at 3:12 AM, rusi <rustompmody at gmail.com> wrote:
> You associate the primal (f)act of thinking about programming with
> *doing* the generating.
> By contrast the functional programmer thinks about what *is* the
> result.

I wish you'd explain that to my boss :) He often has trouble
understanding why sometimes I put two syntactic statements on one
line, such as:

for (int i=0;i<nfoo;++i) if (foo[i].marker)
{
    //do something with foo[i]
}

In Python, that would probably be done with a list comprehension or
some other form of filtered iteration, and is to my mind a single
operation - "iterate over all the marked foo" is just as much a valid
loop header as "iterate over all the foo". This is a simple example,
and what you say about thinking about what *is* the result doesn't
really translate well into a C++ example, but the broader concept
applies: there's a difference between code as the compiler/interpreter
sees it and code as the programmer sees it, and there is not always a
1:1 correspondence of statements.

ChrisA


From damage3025 at gmail.com  Thu May 30 13:46:17 2013
From: damage3025 at gmail.com (Ma Xiaojun)
Date: Fri, 31 May 2013 01:46:17 +0800
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAPTjJmp=5radGce2qEUHRvw1VTk51aj1b6rwgP8fa7BGGrN3aA@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2397.1369904083.3114.python-list@python.org>
	<503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>
	<CAPTjJmp=5radGce2qEUHRvw1VTk51aj1b6rwgP8fa7BGGrN3aA@mail.gmail.com>
Message-ID: <CAGVx7UWnbvRueE0TrnDnnGKuhcpgQeyXRa8Neb-OfLj3Zo3iRQ@mail.gmail.com>

On Fri, May 31, 2013 at 1:28 AM, Chris Angelico <rosuav at gmail.com> wrote:
> for (int i=0;i<nfoo;++i) if (foo[i].marker)
> {
>     //do something with foo[i]
> }

This is interesting!


From rosuav at gmail.com  Thu May 30 13:50:06 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 03:50:06 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAGVx7UWnbvRueE0TrnDnnGKuhcpgQeyXRa8Neb-OfLj3Zo3iRQ@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2397.1369904083.3114.python-list@python.org>
	<503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>
	<CAPTjJmp=5radGce2qEUHRvw1VTk51aj1b6rwgP8fa7BGGrN3aA@mail.gmail.com>
	<CAGVx7UWnbvRueE0TrnDnnGKuhcpgQeyXRa8Neb-OfLj3Zo3iRQ@mail.gmail.com>
Message-ID: <CAPTjJmpFERboxZwJpq+fdrG4KDfACariW2-gtjrcRMmx=c2h4A@mail.gmail.com>

On Fri, May 31, 2013 at 3:46 AM, Ma Xiaojun <damage3025 at gmail.com> wrote:
> On Fri, May 31, 2013 at 1:28 AM, Chris Angelico <rosuav at gmail.com> wrote:
>> for (int i=0;i<nfoo;++i) if (foo[i].marker)
>> {
>>     //do something with foo[i]
>> }
>
> This is interesting!

Yeah, but that's C++. It won't work in Python without this directive:

from __future__ import braces

ChrisA


From damage3025 at gmail.com  Thu May 30 13:50:58 2013
From: damage3025 at gmail.com (Ma Xiaojun)
Date: Fri, 31 May 2013 01:50:58 +0800
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAGVx7UWnbvRueE0TrnDnnGKuhcpgQeyXRa8Neb-OfLj3Zo3iRQ@mail.gmail.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2397.1369904083.3114.python-list@python.org>
	<503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>
	<CAPTjJmp=5radGce2qEUHRvw1VTk51aj1b6rwgP8fa7BGGrN3aA@mail.gmail.com>
	<CAGVx7UWnbvRueE0TrnDnnGKuhcpgQeyXRa8Neb-OfLj3Zo3iRQ@mail.gmail.com>
Message-ID: <CAGVx7UWRgHoRYvmF+O8=RxoGkF2H37POEyxBvgx7H9DqJ_PAHw@mail.gmail.com>

functional VS imperative?

mechanical thinking VS mathematical thinking?

Sounds interesting.


From rustompmody at gmail.com  Thu May 30 13:59:13 2013
From: rustompmody at gmail.com (rusi)
Date: Thu, 30 May 2013 10:59:13 -0700 (PDT)
Subject: How clean/elegant is Python's syntax?
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2397.1369904083.3114.python-list@python.org>
	<503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>
	<mailman.2434.1369934893.3114.python-list@python.org>
Message-ID: <034f2ffa-6bb3-453a-a0f2-b90ecafcda1e@qn4g2000pbc.googlegroups.com>

On May 30, 10:28?pm, Chris Angelico <ros... at gmail.com> wrote:
> On Fri, May 31, 2013 at 3:12 AM, rusi <rustompm... at gmail.com> wrote:
> > You associate the primal (f)act of thinking about programming with
> > *doing* the generating.
> > By contrast the functional programmer thinks about what *is* the
> > result.
>
> I wish you'd explain that to my boss :) He often has trouble
> understanding why sometimes I put two syntactic statements on one
> line, such as:
>
> for (int i=0;i<nfoo;++i) if (foo[i].marker)
> {
> ? ? //do something with foo[i]
>
> }
>
> In Python, that would probably be done with a list comprehension or
> some other form of filtered iteration, and is to my mind a single
> operation - "iterate over all the marked foo" is just as much a valid
> loop header as "iterate over all the foo". This is a simple example,
> and what you say about thinking about what *is* the result doesn't
> really translate well into a C++ example, but the broader concept
> applies: there's a difference between code as the compiler/interpreter
> sees it and code as the programmer sees it, and there is not always a
> 1:1 correspondence of statements.
>
> ChrisA

I had a blog post about line-length in programs
http://blog.languager.org/2012/10/layout-imperative-in-functional.html

followed by an interesting discussion on the haskell mailing list
http://groups.google.com/group/haskell-cafe/browse_thread/thread/f146ec7753c5db56/09eb73b1efe79fec

The comment by Alexander Solla was insightful and is probably what you
are saying.

[Probably!! I am not sure what you are saying!]


From rosuav at gmail.com  Thu May 30 14:22:50 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 04:22:50 +1000
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <034f2ffa-6bb3-453a-a0f2-b90ecafcda1e@qn4g2000pbc.googlegroups.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2397.1369904083.3114.python-list@python.org>
	<503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>
	<mailman.2434.1369934893.3114.python-list@python.org>
	<034f2ffa-6bb3-453a-a0f2-b90ecafcda1e@qn4g2000pbc.googlegroups.com>
Message-ID: <CAPTjJmrVOQ7rwfM0y2CkPZ_G=oZ9yKp7b7zKrHfwt0Y_3vwd4Q@mail.gmail.com>

On Fri, May 31, 2013 at 3:59 AM, rusi <rustompmody at gmail.com> wrote:
> On May 30, 10:28 pm, Chris Angelico <ros... at gmail.com> wrote:
>> On Fri, May 31, 2013 at 3:12 AM, rusi <rustompm... at gmail.com> wrote:
>> > You associate the primal (f)act of thinking about programming with
>> > *doing* the generating.
>> > By contrast the functional programmer thinks about what *is* the
>> > result.
>>
>> I wish you'd explain that to my boss :) He often has trouble
>> understanding why sometimes I put two syntactic statements on one
>> line, such as:
>>
>> for (int i=0;i<nfoo;++i) if (foo[i].marker)
>> {
>>     //do something with foo[i]
>>
>> }
>>
>> In Python, that would probably be done with a list comprehension or
>> some other form of filtered iteration, and is to my mind a single
>> operation - "iterate over all the marked foo" is just as much a valid
>> loop header as "iterate over all the foo". This is a simple example,
>> and what you say about thinking about what *is* the result doesn't
>> really translate well into a C++ example, but the broader concept
>> applies: there's a difference between code as the compiler/interpreter
>> sees it and code as the programmer sees it, and there is not always a
>> 1:1 correspondence of statements.
>>
>> ChrisA
>
> I had a blog post about line-length in programs
> http://blog.languager.org/2012/10/layout-imperative-in-functional.html
>
> followed by an interesting discussion on the haskell mailing list
> http://groups.google.com/group/haskell-cafe/browse_thread/thread/f146ec7753c5db56/09eb73b1efe79fec
>
> The comment by Alexander Solla was insightful and is probably what you
> are saying.
>
> [Probably!! I am not sure what you are saying!]

Unfortunately a lot of your code specifics don't mean much to me
because I don't speak Haskell, but you are making several similar
points. A line of code should not be defined by the language's syntax,
but by the programmer's intention. A Python example might be:

for x in filter(lambda x: x%5 and x%6,range(40)):
    # do something with the numbers that don't count by 5 or 6

Stupid example, but it still puts the conditional inside the loop
header. I'm sure you can come up with a more useful case!

ChrisA


From steve+comp.lang.python at pearwood.info  Thu May 30 15:36:29 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 19:36:29 GMT
Subject: How clean/elegant is Python's syntax?
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2397.1369904083.3114.python-list@python.org>
	<503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>
Message-ID: <51a7aa3c$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Thu, 30 May 2013 10:12:22 -0700, rusi wrote:

> On Thu, May 30, 2013 at 9:34 AM, Ma Xiaojun <damage3025 at gmail.com>
> wrote:

>> Wait a minute! Isn't the most nature way of doing/thinking "generating
>> 9x9 multiplication table" two nested loop?
> 
> Thats like saying that the most natur(al) way of using a car is to
> attach a horse to it.
>[...]
> Likewise in the world of programming, 90% of programmers think
> imperative/OO programming is natural while functional programming is
> strange.  Just wait 10 years and see if things are not drastically
> different!

It won't be. Functional programming goes back to Lisp, which is nearly as 
old as Fortran and older than Cobol. There have been many decades for 
functional languages to become mainstream, but they've never quite done 
it. There's no reason to think that the next decade will see a change to 
this.

That's not to say that functional programming isn't one of the big three 
programming paradigms. But it's third out of the three, and quite a bit 
behind the other two:

Procedural
OOP
Functional

with Logic programming a distant fourth. Well, perhaps even third, ahead 
of Functional, taking into account that SQL is a form of Logic 
programming.

Some modern Functional languages are really neat, like Haskell, but I 
think the sad truth is that to really master them (and not just make do 
with a small percentage of their functionality) is beyond 90% of 
programmers. I'm not ashamed to admit that I struggle with advanced FP 
concepts.

But even if only a minority of programmers can master languages like 
Lisp, Haskell, or Scheme, doesn't mean that *all* programmers can't learn 
something from them. Functional programming is at least 50% a philosophy:

* pass arguments to functions, and return results, rather than getting 
and setting state from a variable.

This is a good strategy: it makes it easier to reason about the code, 
easier to document, easier to test, and makes it practical to use it in 
threaded code.



-- 
Steven


From rustompmody at gmail.com  Thu May 30 22:59:21 2013
From: rustompmody at gmail.com (rusi)
Date: Thu, 30 May 2013 19:59:21 -0700 (PDT)
Subject: How clean/elegant is Python's syntax?
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
	<mailman.2397.1369904083.3114.python-list@python.org>
	<503a1a1e-9c5c-4c01-929b-673421907ab8@ys5g2000pbc.googlegroups.com>
	<51a7aa3c$0$29966$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <abca1938-98f3-4ff2-b462-5f813d81652a@a15g2000pbu.googlegroups.com>

On May 31, 12:36?am, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
>
> But even if only a minority of programmers can master languages like
> Lisp, Haskell, or Scheme, doesn't mean that *all* programmers can't learn
> something from them. Functional programming is at least 50% a philosophy:
>
> * pass arguments to functions, and return results, rather than getting
> and setting state from a variable.

Yes that's the sense in which I am using the term.
More such ideas of FP that can be used by all sorts of programmers
across the board (not just FPers) is here:
http://blog.languager.org/2012/10/functional-programming-lost-booty.html

> On Thu, 30 May 2013 10:12:22 -0700, rusi wrote:
> > On Thu, May 30, 2013 at 9:34 AM, Ma Xiaojun <damage3... at gmail.com>
> > wrote:
> >> Wait a minute! Isn't the most nature way of doing/thinking "generating
> >> 9x9 multiplication table" two nested loop?
>
> > Thats like saying that the most natur(al) way of using a car is to
> > attach a horse to it.
> >[...]
> > Likewise in the world of programming, 90% of programmers think
> > imperative/OO programming is natural while functional programming is
> > strange. ?Just wait 10 years and see if things are not drastically
> > different!
>
> It won't be. Functional programming goes back to Lisp, which is nearly as
> old as Fortran and older than Cobol. There have been many decades for
> functional languages to become mainstream, but they've never quite done
> it. There's no reason to think that the next decade will see a change to
> this.

Depends on how you define your terms.

Comprehensions and lambdas have come into python. From where? [Lambdas
have even got into C++ !!]
Also LINQ in C# is inspired by comprehensions
Generics were not there in C# and Java early editions.  Now they've
been retrofitted -- Origin SML.
Almost every modern language supports garbage collection. Origin Lisp
Numpy is a rip-off of APL. [Ripping off is a tribute. Non-
acknowledgement is sad...]
TAOCP -Vol 1 is a gigantic exercise on how to do lisp without lisp.
Also called Greenspun's 10th law: http://c2.com/cgi/wiki?GreenspunsTenthRuleOfProgramming

> Some modern Functional languages are really neat, like Haskell, but I
> think the sad truth is that to really master them (and not just make do
> with a small percentage of their functionality) is beyond 90% of
> programmers. I'm not ashamed to admit that I struggle with advanced FP
> concepts.

Yes Haskell is HARD. Gets harder with each new major addition.

Which is why I suggest using Haskell core (ie minus most fancy
features) as an *ideology* rather than as a *technology*.
Which is what I am suggesting in my course proposal
https://moocfellowship.org/submissions/the-dance-of-functional-programming-languaging-with-haskell-and-python

"Think with Haskell --- Code into Python"
Want to contribute <wink>?

Well actually the last applies to anyone who is interested --
suggestions welcome!!


From torriem at gmail.com  Thu May 30 19:30:34 2013
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 30 May 2013 17:30:34 -0600
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <51a6ef42$0$11118$c3e8da3@news.astraweb.com>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2374.1369852683.3114.python-list@python.org>
	<51a6ef42$0$11118$c3e8da3@news.astraweb.com>
Message-ID: <51A7E11A.6080700@gmail.com>

On 05/30/2013 12:18 AM, Steven D'Aprano wrote:
> In some ways, Python is a more pure OOP language than Java: everything in 
> Python is an object, including classes themselves.
> 
> In other ways, Python is a less pure and more practical language. You 
> don't have to wrap every piece of functionality in a class. Python 
> encourages you to write mixed procedural, functional and object oriented 
> code, whatever is best for the problem you are trying to solve, which is 
> very much in contrast to Java.

Depending on your understanding of what object-oriented means,
procedural and functional code is still object-oriented.  In fact
modules (the "file") are in essence singleton objects that define
attributes, but in practice there can only be one instance of this
object (module).  Seems like in Java a lot of code is needed to
implement singletons (factory, etc).  module-level code (procedural
code) could simply be thought of as singleton initialization/constructor
code that's automatically run when the singleton is created, using
import or __import__().

At the function level, a simple function is still an object that
implements callable.

Python's implementation of OO isn't quite smalltalk pure, but it is much
more consistent than in Java or C++.

But yes, Python does not force you to shoe-horn your programming into
one particular pattern.


From rantingrickjohnson at gmail.com  Thu May 30 19:15:50 2013
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 30 May 2013 16:15:50 -0700 (PDT)
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <mailman.2388.1369873497.3114.python-list@python.org>
References: <CAGVx7UWXAFHSHq37Ep-Vk=cM2wYrEGHSUhNc8s43bCvj_VcVow@mail.gmail.com>
	<mailman.2388.1369873497.3114.python-list@python.org>
Message-ID: <259c8152-395f-45ce-9912-45ea80d81f65@googlegroups.com>

On Wednesday, May 29, 2013 7:24:48 PM UTC-5, Dan Stromberg wrote:
> About the only thing I don't like is:
> 
> ?? var = 1,
> 
> That binds var to a tuple (singleton) value, instead of 1.

I don't understand why Python needs tuples anyway; at least not tuple literals!. I mean, i like the idea of a sequence type that is immutable as much as the next fella, however, i just hate the fact that we had to pay for this type with syntactical multiplicity only to be forever a slave to it's resulting quirkiness! Psst: Guido, i think you got screwed! 

(And they thought Jack was a fool for acquiring those beans!) 

With the demand for type literals growing all the larger as time goes on and the ASCII char set remaining static, there must be a better way! (And no folks, I'm not suggesting space cadet keyboards!) 


From alister.ware at ntlworld.com  Fri May 31 05:08:43 2013
From: alister.ware at ntlworld.com (Alister)
Date: Fri, 31 May 2013 09:08:43 GMT
Subject: How clean/elegant is Python's syntax?
Message-ID: <vMZpt.7049$2I2.2738@fx17.am4>

On Thu, 30 May 2013 20:38:40 +0100, MRAB wrote:

> On 30/05/2013 19:44, Chris Angelico wrote:
>> On Fri, May 31, 2013 at 4:36 AM, Ian Kelly <ian.g.kelly at gmail.com>
>> wrote:
>>> On Wed, May 29, 2013 at 8:49 PM, rusi <rustompmody at gmail.com> wrote:
>>>> On May 30, 6:14 am, Ma Xiaojun <damage3... at gmail.com> wrote:
>>>>> What interest me is a one liner:
>>>>> print '\n'.join(['\t'.join(['%d*%d=%d' % (j,i,i*j) for i in
>>>>> range(1,10)]) for j in range(1,10)])
>>>>
>>>> Ha,Ha! The join method is one of the (for me) ugly features of
>>>> python.
>>>> You can sweep it under the carpet with a one-line join function and
>>>> then write clean and pretty code:
>>>>
>>>> #joinwith def joinw(l,sep): return sep.join(l)
>>>
>>> I don't object to changing the join method (one of the more
>>> shoe-horned string methods) back into a function, but to my eyes
>>> you've got the arguments backward.  It should be:
>>>
>>> def join(sep, iterable): return sep.join(iterable)
>>
>> Trouble is, it makes some sense either way. I often put the larger
>> argument first - for instance, I would write 123412341324*5 rather than
>> the other way around - and in this instance, it hardly seems as
>> clear-cut as you imply. But the function can't be written to take them
>> in either order, because strings are iterable too. (And functions that
>> take args either way around aren't better than those that make a
>> decision.)
>>
> And additional argument (pun not intended) for putting sep second is
> that you can give it a default value:
> 
>     def join(iterable, sep=""): return sep.join(iterable)

I think that is the winning argument.
Next question is what should be the default ("", " " or',')?



-- 
Nasrudin walked into a teahouse and declaimed, "The moon is more useful
than the sun."
	"Why?", he was asked.
	"Because at night we need the light more."


From fabiosantosart at gmail.com  Fri May 31 06:16:14 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Fri, 31 May 2013 11:16:14 +0100
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <vMZpt.7049$2I2.2738@fx17.am4>
References: <vMZpt.7049$2I2.2738@fx17.am4>
Message-ID: <CAA=1kxQLRYXcB6te1Xh6EoL6Y8V4NUG3gqKCSR89mEeDUg58Hw@mail.gmail.com>

On Fri, May 31, 2013 at 10:08 AM, Alister <alister.ware at ntlworld.com> wrote:
> I think that is the winning argument.
> Next question is what should be the default ("", " " or',')?

join, comma_join, whitejoin, linejoin variants, with different defaults?

--
F?bio Santos


From ian.g.kelly at gmail.com  Fri May 31 11:39:58 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 31 May 2013 09:39:58 -0600
Subject: How clean/elegant is Python's syntax?
In-Reply-To: <CAA=1kxQLRYXcB6te1Xh6EoL6Y8V4NUG3gqKCSR89mEeDUg58Hw@mail.gmail.com>
References: <vMZpt.7049$2I2.2738@fx17.am4>
	<CAA=1kxQLRYXcB6te1Xh6EoL6Y8V4NUG3gqKCSR89mEeDUg58Hw@mail.gmail.com>
Message-ID: <CALwzidnnp8V2oSCuSbix4r7SaS6G9MkMo8Oyfg4gqJvzJy-f7A@mail.gmail.com>

On Fri, May 31, 2013 at 4:16 AM, F?bio Santos <fabiosantosart at gmail.com> wrote:
> On Fri, May 31, 2013 at 10:08 AM, Alister <alister.ware at ntlworld.com> wrote:
>> I think that is the winning argument.
>> Next question is what should be the default ("", " " or',')?
>
> join, comma_join, whitejoin, linejoin variants, with different defaults?

The more specific versions should not even have the parameter as an
argument that can be supplied.  Otherwise you could do:

comma_join(words, sep=';')

which is just unclear, and there is no reason to allow it.


From rustompmody at gmail.com  Fri May 31 06:27:52 2013
From: rustompmody at gmail.com (rusi)
Date: Fri, 31 May 2013 03:27:52 -0700 (PDT)
Subject: How clean/elegant is Python's syntax?
References: <vMZpt.7049$2I2.2738@fx17.am4>
Message-ID: <51ff2721-d27e-466e-83e4-9ecc877d5583@fq2g2000pbb.googlegroups.com>

On May 31, 2:08?pm, Alister <alister.w... at ntlworld.com> wrote:
> On Thu, 30 May 2013 20:38:40 +0100, MRAB wrote:
> > And additional argument (pun not intended) for putting sep second is
> > that you can give it a default value:
>
> > ? ? def join(iterable, sep=""): return sep.join(iterable)
>
> I think that is the winning argument.

Yes

> Next question is what should be the default ("", " " or',')?

Hmm... Never thought there was any choice here except "".  Yes can see
the case for each.


From alister.ware at ntlworld.com  Fri May 31 07:52:11 2013
From: alister.ware at ntlworld.com (Alister)
Date: Fri, 31 May 2013 11:52:11 GMT
Subject: How clean/elegant is Python's syntax?
References: <vMZpt.7049$2I2.2738@fx17.am4>
	<51ff2721-d27e-466e-83e4-9ecc877d5583@fq2g2000pbb.googlegroups.com>
Message-ID: <L90qt.8321$RF7.3110@fx07.am4>

On Fri, 31 May 2013 03:27:52 -0700, rusi wrote:

> On May 31, 2:08?pm, Alister <alister.w... at ntlworld.com> wrote:
>> On Thu, 30 May 2013 20:38:40 +0100, MRAB wrote:
>> > And additional argument (pun not intended) for putting sep second is
>> > that you can give it a default value:
>>
>> > ? ? def join(iterable, sep=""): return sep.join(iterable)
>>
>> I think that is the winning argument.
> 
> Yes
> 
>> Next question is what should be the default ("", " " or',')?
> 
> Hmm... Never thought there was any choice here except "".  Yes can see
> the case for each.

to be fair "" is probably the most sensible although in my programs most 
joins are using ','



-- 
We are governed not by armies and police but by ideas.
		-- Mona Caird, 1892


From mattjamesfrancis at gmail.com  Thu May 30 00:27:54 2013
From: mattjamesfrancis at gmail.com (Matthew Francis)
Date: Wed, 29 May 2013 21:27:54 -0700 (PDT)
Subject: Building a HPC data assimilation system using Python?
Message-ID: <676e9ba9-c54a-404a-8602-fa078cf19c32@googlegroups.com>

I have a prototype data assimilation code ( an ionospheric nowcast/forecast model driven by GPS data ) that is written in IDL (interactive data language) which is a horrible language choice for scaling the application up to large datasets as IDL is serial and slow (interpreted).

I am embarking on a project to convert this prototype into an operational parallel HPC code. In the past I've used C++ for this kind of project and am comfortable using MPI. On the other hand, I've recently started using python and appreciate the flexibility and speed of development using python compared with C++. I have read that there is a trend to use python as the high level 'glue' for these kind of large number crunching projects, so it would seem appropriate to go down that path. There are a number of C++ and FORTRAN(!) libraries I'd need to incorporate that handle things such as the processing of raw GPS data and computing ionospheric models, so I'd need to be able to make the appropriate interface for these into python.

If anyone uses python is this way, I'd appreciate any tips, hints, things to be careful about and in general any war stories you can relate that you wish you'd heard before making some mistake.

Here are the things I have investigated that it looks like I'd probably need to use:

* scipy/numpy/matplotlib
* Cython (or pyrex?) for speeding up any bottlenecks that occur in python code (as opposed to C++/FORTRAN libraries)
* MPI for Python (mpi4py). Does this play nice with Cython?
* Something to interface python with other language libraries. ctypes, swig, boost? Which would be best for this application?
* Profiling. profile/cprofile are straightforward to use, but how do they cope with a parallel (mpi4py) code?
* If a C++ library call has its own MPI calls, does that work smoothly with mpi4py operating in the python part of the code?

Sorry if some of this is a little basic, I'm trying to get up to speed on this a quick as I can.

Thanks in advance!


From carlosnepomuceno at outlook.com  Thu May 30 18:34:26 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 31 May 2013 01:34:26 +0300
Subject: Building a HPC data assimilation system using Python?
In-Reply-To: <676e9ba9-c54a-404a-8602-fa078cf19c32@googlegroups.com>
References: <676e9ba9-c54a-404a-8602-fa078cf19c32@googlegroups.com>
Message-ID: <BLU176-W144EC6ECBC6A3C8FAAFA67D7910@phx.gbl>

Hi Matthew! I'm on a similar quest!

I'm still learning the basics of Python so I may not be a good source of information.

I'm reading a lot of stuff about how to use Python for the parallelization of code and data and found BSP[1] to be very interesting and perhaps worth the time to learn it! ;)


[1] http://www.multicorebsp.com/



----------------------------------------
> Date: Wed, 29 May 2013 21:27:54 -0700
> Subject: Building a HPC data assimilation system using Python?
> From: mattjamesfrancis at gmail.com
> To: python-list at python.org
>
> I have a prototype data assimilation code ( an ionospheric nowcast/forecast model driven by GPS data ) that is written in IDL (interactive data language) which is a horrible language choice for scaling the application up to large datasets as IDL is serial and slow (interpreted).
>
> I am embarking on a project to convert this prototype into an operational parallel HPC code. In the past I've used C++ for this kind of project and am comfortable using MPI. On the other hand, I've recently started using python and appreciate the flexibility and speed of development using python compared with C++. I have read that there is a trend to use python as the high level 'glue' for these kind of large number crunching projects, so it would seem appropriate to go down that path. There are a number of C++ and FORTRAN(!) libraries I'd need to incorporate that handle things such as the processing of raw GPS data and computing ionospheric models, so I'd need to be able to make the appropriate interface for these into python.
>
> If anyone uses python is this way, I'd appreciate any tips, hints, things to be careful about and in general any war stories you can relate that you wish you'd heard before making some mistake.
>
> Here are the things I have investigated that it looks like I'd probably need to use:
>
> * scipy/numpy/matplotlib
> * Cython (or pyrex?) for speeding up any bottlenecks that occur in python code (as opposed to C++/FORTRAN libraries)
> * MPI for Python (mpi4py). Does this play nice with Cython?
> * Something to interface python with other language libraries. ctypes, swig, boost? Which would be best for this application?
> * Profiling. profile/cprofile are straightforward to use, but how do they cope with a parallel (mpi4py) code?
> * If a C++ library call has its own MPI calls, does that work smoothly with mpi4py operating in the python part of the code?
>
> Sorry if some of this is a little basic, I'm trying to get up to speed on this a quick as I can.
>
> Thanks in advance!
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From bhk755 at gmail.com  Thu May 30 05:48:54 2013
From: bhk755 at gmail.com (bhk755 at gmail.com)
Date: Thu, 30 May 2013 02:48:54 -0700 (PDT)
Subject: Can anyone please help me in understanding the following python code
Message-ID: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>

Code :
-----
def mergeSort(alist):
    print("Splitting ",alist)
    if len(alist)>1:
        mid = len(alist)//2
        lefthalf = alist[:mid]
        righthalf = alist[mid:]

        mergeSort(lefthalf)
        mergeSort(righthalf)

        i=0
        j=0
        k=0
        while i<len(lefthalf) and j<len(righthalf):
            if lefthalf[i]<righthalf[j]:
                alist[k]=lefthalf[i]
                i=i+1
            else:
                alist[k]=righthalf[j]
                j=j+1
            k=k+1

        while i<len(lefthalf):
            alist[k]=lefthalf[i]
            i=i+1
            k=k+1

        while j<len(righthalf):
            alist[k]=righthalf[j]
            j=j+1
            k=k+1
    print("Merging ",alist)

alist = [54,26,93,17,77,31,44,55,20]
mergeSort(alist)
print(alist)

Output:
-------
('Splitting ', [54, 26, 93, 17, 77, 31, 44, 55, 20])
('Splitting ', [54, 26, 93, 17])
('Splitting ', [54, 26])
('Splitting ', [54])
('Merging ', [54])
('Splitting ', [26])
('Merging ', [26])
('Merging ', [26, 54])
('Splitting ', [93, 17])
('Splitting ', [93])
('Merging ', [93])
('Splitting ', [17])
('Merging ', [17])
('Merging ', [17, 93])
('Merging ', [17, 26, 54, 93])
('Splitting ', [77, 31, 44, 55, 20])
('Splitting ', [77, 31])
('Splitting ', [77])
('Merging ', [77])
('Splitting ', [31])
('Merging ', [31])
('Merging ', [31, 77])
('Splitting ', [44, 55, 20])
('Splitting ', [44])
('Merging ', [44])
('Splitting ', [55, 20])
('Splitting ', [55])
('Merging ', [55])
('Splitting ', [20])
('Merging ', [20])
('Merging ', [20, 55])
('Merging ', [20, 44, 55])
('Merging ', [20, 31, 44, 55, 77])
('Merging ', [17, 20, 26, 31, 44, 54, 55, 77, 93])
[17, 20, 26, 31, 44, 54, 55, 77, 93]


Question:
---------
Function mergeSort is called only once, but it is getting recursively executed after the printing the last statement "print("Merging ",alist)". But don't recursion taking place except at these places "mergeSort(lefthalf), mergeSort(righthalf)"

Sometimes the function execution directly starts from i=0,j=0,k=0 . Not sure how.

Can anyone please help me out here?




From rosuav at gmail.com  Thu May 30 06:01:19 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 20:01:19 +1000
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
Message-ID: <CAPTjJmo7vrWJh78wu8Ea_mX2fF3M=D2fLiA29bW1EJF7OHwZ7w@mail.gmail.com>

On Thu, May 30, 2013 at 7:48 PM,  <bhk755 at gmail.com> wrote:
> Function mergeSort is called only once, but it is getting recursively executed after the printing the last statement "print("Merging ",alist)". But don't recursion taking place except at these places "mergeSort(lefthalf), mergeSort(righthalf)"
>
> Sometimes the function execution directly starts from i=0,j=0,k=0 . Not sure how.

When it says "Splitting" with a single-element list, it then
immediately prints "Merging" and returns (because all the rest of the
code is guarded by the 'if'). Execution then continues where it left
off, in the parent.

One good way to get an idea of what's going on is to add a recursion
depth parameter. Keep all the rest of the code the same, but change
the print and recursion lines to be like this:

def mergeSort(alist,depth):
    print("%*cSplitting %r"%(depth*2,' ',alist))
    # ...
        mergeSort(lefthalf,depth+1)
        mergeSort(righthalf,depth+1)
    # ...
    print("%*cMerging %r"%(depth*2,' ',alist))

mergeSort(alist,0)

That'll indent everything according to the depth of the call stack.
(Also, I changed your 'print's to be compatible with Python 2 and
Python 3; you seemed to have Python 3 style function calls and a
Python 2 interpreter.) Hopefully that'll make clearer what's going on!

ChrisA


From wolfgang.maier at biologie.uni-freiburg.de  Thu May 30 06:17:11 2013
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Thu, 30 May 2013 10:17:11 +0000 (UTC)
Subject: Can anyone please help me in understanding the following python
	code
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
Message-ID: <loom.20130530T120207-635@post.gmane.org>

 <bhk755 <at> gmail.com> writes:
>
> 
> Function mergeSort is called only once, but it is getting recursively
executed after the printing the last
> statement "print("Merging ",alist)". But don't recursion taking place
except at these places
> "mergeSort(lefthalf), mergeSort(righthalf)"
> 
> Sometimes the function execution directly starts from i=0,j=0,k=0 . Not
sure how.

Maybe you should tell us first what output you would have expected.
It's not really clear from your question what confuses you. Doesn't the
algorithm do what it's supposed to do? When does the function start from
i=0, j=0, k=0 ? What exactly is the output then ?
Maybe you are confused by the fact that the algorithm is recursive twice. It
first goes through the lefthand branch, then only on its way out it works on
the righthand branch. So the recursion through mergeSort is not started only
once as you say, but twice (after finishing the recursion through
mergeSort(lefthand), another recursion is kicked off by calling
mergeSort(righthand).
Best,
Wolfgang




From bhk755 at gmail.com  Thu May 30 06:19:59 2013
From: bhk755 at gmail.com (bhk755 at gmail.com)
Date: Thu, 30 May 2013 03:19:59 -0700 (PDT)
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
Message-ID: <fd037baa-b5b0-435e-b035-4e25b0d3acbd@googlegroups.com>

Thanks for the reply Chris.

I am newbie to python, so please excuse me if I am asking chilly questions.

Can you please explain more about the following sentence.
"When it says "Splitting" with a single-element list, it then 
immediately prints "Merging" and returns (because all the rest of the 
code is guarded by the 'if'). Execution then continues where it left 
off, in the parent."

Because I am not sure how the control can go back to top of the function unless  there is no loops there.

Also, Can you please let me know how did you found out that I am using Python 2 Interpreter.


Bharath



From wolfgang.maier at biologie.uni-freiburg.de  Thu May 30 06:43:52 2013
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Thu, 30 May 2013 10:43:52 +0000 (UTC)
Subject: Can anyone please help me in understanding the following
	=?utf-8?b?cHl0aG9uCWNvZGU=?=
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
	<fd037baa-b5b0-435e-b035-4e25b0d3acbd@googlegroups.com>
Message-ID: <loom.20130530T123916-790@post.gmane.org>

 <bhk755 <at> gmail.com> writes:

> 
> Thanks for the reply Chris.
> 
> I am newbie to python, so please excuse me if I am asking chilly questions.
> 
> Can you please explain more about the following sentence.
> "When it says "Splitting" with a single-element list, it then 
> immediately prints "Merging" and returns (because all the rest of the 
> code is guarded by the 'if'). Execution then continues where it left 
> off, in the parent."
> 
> Because I am not sure how the control can go back to top of the function
unless  there is no loops there.
>

It doesn't. The function simply returns and execution resumes in the parent,
i.e. in the calling function at depth-1, where it left off. In Python, a
return None is implied when a function falls off its end.

> Also, Can you please let me know how did you found out that I am using
Python 2 Interpreter.

print as a statement (without parentheses) only works in Python 2, in Python
3 print is a function.

> 
> Bharath
> 
> 






From rosuav at gmail.com  Thu May 30 06:47:22 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 20:47:22 +1000
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <fd037baa-b5b0-435e-b035-4e25b0d3acbd@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
	<fd037baa-b5b0-435e-b035-4e25b0d3acbd@googlegroups.com>
Message-ID: <CAPTjJmo4w_TepXtNibcLMP1UE5t-bo=7cGG=h8T6Oq3CGQGAvQ@mail.gmail.com>

On Thu, May 30, 2013 at 8:19 PM,  <bhk755 at gmail.com> wrote:
> Thanks for the reply Chris.
>
> I am newbie to python, so please excuse me if I am asking chilly questions.

All questions are welcome!

> Can you please explain more about the following sentence.
> "When it says "Splitting" with a single-element list, it then
> immediately prints "Merging" and returns (because all the rest of the
> code is guarded by the 'if'). Execution then continues where it left
> off, in the parent."

The code goes like this:

1) Print "Splitting"
2) If there's more than one element in the list:
2a) Divide the list in half
2b) Call self on each half
2c) Merge
3) Print "Merging

In step 2b, all the steps from 1 through 3 are executed again (twice).
Soon, those calls will just output "Splitting" followed by "Merging";
and then we go back to 2c. That's why it *seems* that the code goes
from 3 to 2c. You'll notice that the call depth decreases when this
happens.

> Because I am not sure how the control can go back to top of the function unless  there is no loops there.
>
> Also, Can you please let me know how did you found out that I am using Python 2 Interpreter.

That one is actually based on my crystal ball. Here on python-list, we
issue them to all our top respondents; they're extremely useful. I'll
let you in on part of the secret of how this works, though.

In Python 2, 'print' is (by default) a statement. When you give it
something in parentheses, it sees a tuple:

print("Splitting ",alist)
('Splitting ', [54, 26, 93, 17, 77, 31, 44, 55, 20])

In Python 3, 'print' is a function. It takes arguments, and prints out
each argument, separated by spaces.

print("Splitting ",alist)
Splitting  [17, 20, 26, 31, 44, 54, 55, 77, 93]

You can make Python 2 behave the same way by putting this at the top
of your program:

from __future__ import print_function

ChrisA


From joshua.landau.ws at gmail.com  Thu May 30 07:11:38 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Thu, 30 May 2013 12:11:38 +0100
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <fd037baa-b5b0-435e-b035-4e25b0d3acbd@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
	<fd037baa-b5b0-435e-b035-4e25b0d3acbd@googlegroups.com>
Message-ID: <CAN1F8qV2QbqN79zALMMo1p+SZamscmmKygqBismQdnzeGUEpUw@mail.gmail.com>

On 30 May 2013 11:19,  <bhk755 at gmail.com> wrote:
> Also, Can you please let me know how did you found out that I am using Python 2 Interpreter.

Do you have access to a Python3 interpreter? If so, try running it and
your output will look like:

Splitting  [54, 26, 93, 17, 77, 31, 44, 55, 20]
Splitting  [54, 26, 93, 17]
Splitting  [54, 26]
Splitting  [54]
Merging  [54]
Splitting  [26]
Merging  [26]
... BLAH BLAH BLAH

Which is obviously much nicer. This is how Chris knew the code was
written for Python3. Therefore I would suggest you use Python3 - not
all code runs on both!

The "proper" way to write the prints for Python2 is without the brackets:

print "Merging ",alist

But the methods Chris and I have used work the same on both so are
probably better in this case. They're more complicated, though.


From joshua.landau.ws at gmail.com  Thu May 30 07:03:22 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Thu, 30 May 2013 12:03:22 +0100
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
Message-ID: <CAN1F8qWZwFNXbF9Bp8UpBTjseGNNBu+L4jDfgWpQ-r2N43vxyQ@mail.gmail.com>

On 30 May 2013 10:48,  <bhk755 at gmail.com> wrote:
> Question:
> ---------
> Function mergeSort is called only once, but it is getting recursively executed after the printing the last statement "print("Merging ",alist)". But don't recursion taking place except at these places "mergeSort(lefthalf), mergeSort(righthalf)"
>
> Sometimes the function execution directly starts from i=0,j=0,k=0 . Not sure how.

Here's some different code; it does the same thing but in a less weird way:

##########################
def mergeSort(alist, depth=1):
    # If the piece we have to sort is [i] or [], then we have no sorting to do
    if len(alist) <= 1:
        # Returning what we were given
        # Make a new list from it, though, because we are nice
        print("{padding}return {list}\n".format(padding=" "*depth*8,
list=alist))
        return alist[:]

    # Split along the middle
    mid = len(alist)//2

    # We have two halves
    lefthalf = alist[:mid]
    righthalf = alist[mid:]

    # Which we sort, so we have two sorted halves
    print("{padding}lefthalf  = mergesort({list})\n".format(padding="
"*depth*8, list=lefthalf))
    lefthalf  = mergeSort(lefthalf,  depth+1)

    print("{padding}righthalf = mergesort({list})\n".format(padding="
"*depth*8, list=righthalf))
    righthalf = mergeSort(righthalf, depth+1)


    # We want to return a sorted "alist" from our two lists
    # We'll add the items to here
    new_list = []

    # We'll go through adding the smallest to new_list
    while lefthalf and righthalf:

        # Lefthalf has the smaller item, so we "pop" it off into new_list
        if lefthalf[0] < righthalf[0]:
            new_list.append(lefthalf.pop(0))

        # Righthalf has the smaller item, so we "pop" it off into new_list
        else:
            new_list.append(righthalf.pop(0))

    # One of our lists isn't empty, so just add them on
    new_list += lefthalf + righthalf

    print("{padding}return {list}\n".format(padding=" "*depth*8, list=new_list))
    return new_list

print("Start mergesort({list}):\n".format(list=[2, 4, 0, 1]))

sorted_list = mergeSort([2, 4, 0, 1])

print("Our final result: {list}".format(list=sorted_list))
##########################

And it gives

##########################
Start mergesort([2, 4, 0, 1]):

        lefthalf  = mergesort([2, 4])

                lefthalf  = mergesort([2])

                        return [2]

                righthalf = mergesort([4])

                        return [4]

                return [2, 4]

        righthalf = mergesort([0, 1])

                lefthalf  = mergesort([0])

                        return [0]

                righthalf = mergesort([1])

                        return [1]

                return [0, 1]

        return [0, 1, 2, 4]

Our final result: [0, 1, 2, 4]
##########################

Hopefully this code is a little easier to understand - the original
changes the list while it is running the algorithm and mine makes new
lists. The algorithm is very similar, and what you learn applies to
both.

You can see in the output (thanks Chris Angelico) that the main
function is always running. It runs *two* other instances: lefthalf
and righthalf.

So the "mergesort([2, 4, 0, 1])" runs "lefthalf  = mergesort([2, 4])"

"mergesort([2, 4])" runs "lefthalf  = mergesort([2])"

"mergesort([2])" gives back [2] to "mergesort([2, 4])"

"mergesort([2, 4])" goes "OH! I can continue now" and runs "righthalf
= mergesort([4])"

"mergesort([4])" gives back [4] to "mergesort([2, 4])"

"mergesort([2, 4])" goes "OH! I can continue now" and gives back [2,
4] to "mergesort([2, 4, 0, 1])"

"mergesort([2, 4, 0, 1])" goes "OH! I can continue now" and runs
"righthalf = mergesort([0, 1])"

"mergesort([0, 1])" runs "lefthalf  = mergesort([0])"

"mergesort([0])" gives back [0] to "mergesort([0, 1])"

"mergesort([0, 1])" goes "OH! I can continue now" and runs "righthalf
= mergesort([1])"

"mergesort([1])" gives back [1] to "mergesort([0, 1])"

"mergesort([0, 1])" goes "OH! I can continue now" and gives back [0,
1] to "mergesort([2, 4, 0, 1])"

"mergesort([2, 4, 0, 1])" goes "OH! I can continue now" and gives back
[0, 1, 2, 4]

DONE.

Does that help you see the flow?



Exactly the same flow happens for your code. The difference is that
instead of returning a list, mergesort *sorts* a list, and then that
is used to replace items in the original list. Personally, their way
is a little silly (and mine is inefficient, so use neither).


Question: Why did you rewrite the code?
Answer: Revising is boring.


Question: Sometimes the function execution directly starts from
i=0,j=0,k=0 . Not sure how.
Answer: That's not a question. Anyhow:

i, j and k are LOCAL to a function. "mergesort([2, 4, 0, 1])" has a
different i, j and k than "mergesort([0, 1])", They never use each
other's i, j and k. Hence for each recursion they run "i=0, j=0, k=0"
and they are set to 0 within the function.


Does this help?


From bhk755 at gmail.com  Thu May 30 08:39:20 2013
From: bhk755 at gmail.com (bhk755 at gmail.com)
Date: Thu, 30 May 2013 05:39:20 -0700 (PDT)
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
Message-ID: <384a9b8f-40e0-4c8c-b15f-0c96512f67f1@googlegroups.com>

Thanks Chris, Wolfgang and Joshua for your replies.

---
In step 2b, all the steps from 1 through 3 are executed again (twice). 
Soon, those calls will just output "Splitting" followed by "Merging"; 
and then we go back to 2c. That's why it *seems* that the code goes 
from 3 to 2c. You'll notice that the call depth decreases when this 
happens

Chris, Can you please let me know what makes the control of the program code go to  2c after the output "Merging". 

Also, please look into the following output, 



 before calling main mergesort

 Splitting [54, 26, 93, 17, 77, 31, 44, 55, 20]
left half before split  [54, 26, 93, 17]
right half before split [77, 31, 44, 55, 20]
  Splitting [54, 26, 93, 17]
left half before split  [54, 26]
right half before split [93, 17]
    Splitting [54, 26]
left half before split  [54]
right half before split [26]
      Splitting [54]
      Merging [54]
      Splitting [26]
      Merging [26]

HERE AFTER SPLIT

left half after split [54]
right half after split [26]
    Merging [26, 54]
    Splitting [93, 17]
left half before split  [93]
right half before split [17]
      Splitting [93]
      Merging [93]
      Splitting [17]
      Merging [17]

HERE AFTER SPLIT

left half after split [93]
right half after split [17]
    Merging [17, 93]

HERE AFTER SPLIT

left half after split [26, 54]
right half after split [17, 93]
  Merging [17, 26, 54, 93]
  Splitting [77, 31, 44, 55, 20]
left half before split  [77, 31]
right half before split [44, 55, 20]
    Splitting [77, 31]
left half before split  [77]
right half before split [31]
      Splitting [77]
      Merging [77]
      Splitting [31]
      Merging [31]

HERE AFTER SPLIT

left half after split [77]
right half after split [31]
    Merging [31, 77]
    Splitting [44, 55, 20]
left half before split  [44]
right half before split [55, 20]
      Splitting [44]
      Merging [44]
      Splitting [55, 20]
left half before split  [55]
right half before split [20]
        Splitting [55]
        Merging [55]
        Splitting [20]
        Merging [20]

HERE AFTER SPLIT

left half after split [55]
right half after split [20]
      Merging [20, 55]

HERE AFTER SPLIT

left half after split [44]
right half after split [20, 55]
    Merging [20, 44, 55]

HERE AFTER SPLIT

left half after split [31, 77]
right half after split [20, 44, 55]
  Merging [20, 31, 44, 55, 77]

HERE AFTER SPLIT

left half after split [17, 26, 54, 93]
right half after split [20, 31, 44, 55, 77]
 Merging [17, 20, 26, 31, 44, 54, 55, 77, 93]

 after calling main mergesort

[17, 20, 26, 31, 44, 54, 55, 77, 93]

-----------------------------

In the above output, the control goes to "HERE AFTER SPLIT" after the "Merging" statement which is of-course the last statement in the function.On what condition this is happening.
Ideally as per my understanding, after the last statement of a function the control should come out of the function. 
Please correct me if I am wrong here.
There is something with respect-to functions in python that I am not able to understand.



From bhk755 at gmail.com  Thu May 30 08:42:33 2013
From: bhk755 at gmail.com (bhk755 at gmail.com)
Date: Thu, 30 May 2013 05:42:33 -0700 (PDT)
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <384a9b8f-40e0-4c8c-b15f-0c96512f67f1@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
	<384a9b8f-40e0-4c8c-b15f-0c96512f67f1@googlegroups.com>
Message-ID: <ccb5c332-4b5e-44e3-ab9b-1d815c73548b@googlegroups.com>

On Thursday, May 30, 2013 6:09:20 PM UTC+5:30, bhk... at gmail.com wrote:
> Thanks Chris, Wolfgang and Joshua for your replies.
> 
> 
> 
> ---
> 
> In step 2b, all the steps from 1 through 3 are executed again (twice). 
> 
> Soon, those calls will just output "Splitting" followed by "Merging"; 
> 
> and then we go back to 2c. That's why it *seems* that the code goes 
> 
> from 3 to 2c. You'll notice that the call depth decreases when this 
> 
> happens
> 
> 
> 
> Chris, Can you please let me know what makes the control of the program code go to  2c after the output "Merging". 
> 
> Also, please look into the following output for the same program with more print statements, 
> ---------------------------------------------- 
>  before calling main mergesort 
> 
>  Splitting [54, 26, 93, 17, 77, 31, 44, 55, 20]
> 
> left half before split  [54, 26, 93, 17]
> 
> right half before split [77, 31, 44, 55, 20]
> 
>   Splitting [54, 26, 93, 17]
> 
> left half before split  [54, 26]
> 
> right half before split [93, 17]
> 
>     Splitting [54, 26]
> 
> left half before split  [54]
> 
> right half before split [26]
> 
>       Splitting [54]
> 
>       Merging [54]
> 
>       Splitting [26]
> 
>       Merging [26]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [54]
> 
> right half after split [26]
> 
>     Merging [26, 54]
> 
>     Splitting [93, 17]
> 
> left half before split  [93]
> 
> right half before split [17]
> 
>       Splitting [93]
> 
>       Merging [93]
> 
>       Splitting [17]
> 
>       Merging [17]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [93]
> 
> right half after split [17]
> 
>     Merging [17, 93]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [26, 54]
> 
> right half after split [17, 93]
> 
>   Merging [17, 26, 54, 93]
> 
>   Splitting [77, 31, 44, 55, 20]
> 
> left half before split  [77, 31]
> 
> right half before split [44, 55, 20]
> 
>     Splitting [77, 31]
> 
> left half before split  [77]
> 
> right half before split [31]
> 
>       Splitting [77]
> 
>       Merging [77]
> 
>       Splitting [31]
> 
>       Merging [31]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [77]
> 
> right half after split [31]
> 
>     Merging [31, 77]
> 
>     Splitting [44, 55, 20]
> 
> left half before split  [44]
> 
> right half before split [55, 20]
> 
>       Splitting [44]
> 
>       Merging [44]
> 
>       Splitting [55, 20]
> 
> left half before split  [55]
> 
> right half before split [20]
> 
>         Splitting [55]
> 
>         Merging [55]
> 
>         Splitting [20]
> 
>         Merging [20]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [55]
> 
> right half after split [20]
> 
>       Merging [20, 55]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [44]
> 
> right half after split [20, 55]
> 
>     Merging [20, 44, 55]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [31, 77]
> 
> right half after split [20, 44, 55]
> 
>   Merging [20, 31, 44, 55, 77]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [17, 26, 54, 93]
> 
> right half after split [20, 31, 44, 55, 77]
> 
>  Merging [17, 20, 26, 31, 44, 54, 55, 77, 93]
> 
> 
> 
>  after calling main mergesort
> 
> 
> 
> [17, 20, 26, 31, 44, 54, 55, 77, 93]
> 
> -------------------------------------------------------
>  
> In the above output, the control goes to "HERE AFTER SPLIT" after the "Merging" statement which is of-course the last statement in the function.On what condition this is happening.
> 
> Ideally as per my understanding, after the last statement of a function the control should come out of the function. 
> 
> Please correct me if I am wrong here.
> 
> There is something with respect-to functions in python that I am not able to understand.



From davea at davea.name  Thu May 30 09:29:52 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 30 May 2013 09:29:52 -0400
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <ccb5c332-4b5e-44e3-ab9b-1d815c73548b@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
	<384a9b8f-40e0-4c8c-b15f-0c96512f67f1@googlegroups.com>
	<ccb5c332-4b5e-44e3-ab9b-1d815c73548b@googlegroups.com>
Message-ID: <51A75450.6090903@davea.name>

On 05/30/2013 08:42 AM, bhk755 at gmail.com wrote:

     <SNIP lots of double-spaced googlegroups nonsense.  Please read
              this http://wiki.python.org/moin/GoogleGroupsPython  >


>>
>> In the above output, the control goes to "HERE AFTER SPLIT" after the "Merging" statement which is of-course the last statement in the function.On what condition this is happening.
>>
>> Ideally as per my understanding, after the last statement of a function the control should come out of the function.
>>
>> Please correct me if I am wrong here.
>>
>> There is something with respect-to functions in python that I am not able to understand.
>

I think you misunderstand recursion.  And you should study it in a 
simpler example before trying to tackle that sort function.

After the last statement of a function, or after an explicit return 
statement, the function does indeed return control to whoever called it. 
  And if the call was in the middle of some other function, that's the 
place where execution will continue.  Functions may nest this way to 
pretty large depths of complexity.

If you're not sure you understand that, we should stop here.  So in your 
reply, tell me if you can readily grasp function dfunc() calling 
cfunc(), which calls bfunc(), which calls afunc().  When afunc() 
returns, you'll be right in the middle of bfunc(), right after the call 
was made.

Now to recursion.  One can write a function which solves a particular 
problem by doing some of the work, but by calling on other functions 
which solve simpler subproblems.  Recursion comes in when those other 
functions are simply instances of the same one.  So instead of dfunc() 
calling cfunc(), we have rfunc() calling rfunc() calling rfunc() calling 
rfunc().

Let's take a classic problem for explaining recursion:  factorial.

We can write a simple function that solves the problem for 0:

def afunc(n):
     if n == 0:
          return 1
     else:
          throw-some-exception

Silly function, I know.  Now let's write one that solves it for one.

def bfunc(n):
     if n == 1:
          return 1 * afunc(n-1)
     else:
          throw-some-exception

Now for two:

def bfunc(n):
     if n == 2:
          return 2 * bfunc(n-1)
     else:
          throw-some-exception


Notice that each function calls the one above it to solve the "simpler" 
problem.  Now if we wanted this to work for n=100, it would get really 
tedious.  So let's see if we can write one function that handles all of 
these cases.

def rfunc(n):
     if n == 0:
         return 1
     else:
         return n * rfunc(n-1)

Now if we call this with n==3, it'll make the zero check, then it'll 
call another function with the value 2.  that one will in turn call 
another function with the value 1.  And so on.  So this function calls 
itself, as we say recursively.

Now, for this simple case, we could have used a simple loop, or just 
called the library function.  But it's a simple enough example to follow 
in its entirety (if I've been clear in my writing).

Your mergeSort() function calls itself recursively, and each time it 
does, it passes a *smaller* list to be sorted.  Eventually the calls 
recurse down to a list of size 1, which is already sorted by definition. 
  The check for that is the line

   if len(alist)>1:

near the beginning of the function.  That's analogous to my if n==0 
line, although to match it most directly, I could have reversed the 
if/else and written the test as if n!=0

Chris showed you how to change your output so you could see the nesting 
levels.  I have done that sort of thing in the past, and found it very 
useful.  But first you have to understand nested functions, and simple 
recursion.


-- 
DaveA


From bhk755 at gmail.com  Thu May 30 08:42:46 2013
From: bhk755 at gmail.com (bhk755 at gmail.com)
Date: Thu, 30 May 2013 05:42:46 -0700 (PDT)
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <384a9b8f-40e0-4c8c-b15f-0c96512f67f1@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
	<384a9b8f-40e0-4c8c-b15f-0c96512f67f1@googlegroups.com>
Message-ID: <371ae93a-bc1e-4e79-910d-c7225c35cd9e@googlegroups.com>

On Thursday, May 30, 2013 6:09:20 PM UTC+5:30, bhk... at gmail.com wrote:
> Thanks Chris, Wolfgang and Joshua for your replies.
> 
> 
> 
> ---
> 
> In step 2b, all the steps from 1 through 3 are executed again (twice). 
> 
> Soon, those calls will just output "Splitting" followed by "Merging"; 
> 
> and then we go back to 2c. That's why it *seems* that the code goes 
> 
> from 3 to 2c. You'll notice that the call depth decreases when this 
> 
> happens
> 
> 
> 
> Chris, Can you please let me know what makes the control of the program code go to  2c after the output "Merging". 
> 
> Also, please look into the following output for the same program with more print statements, 
> ---------------------------------------------- 
>  before calling main mergesort 
> 
>  Splitting [54, 26, 93, 17, 77, 31, 44, 55, 20]
> 
> left half before split  [54, 26, 93, 17]
> 
> right half before split [77, 31, 44, 55, 20]
> 
>   Splitting [54, 26, 93, 17]
> 
> left half before split  [54, 26]
> 
> right half before split [93, 17]
> 
>     Splitting [54, 26]
> 
> left half before split  [54]
> 
> right half before split [26]
> 
>       Splitting [54]
> 
>       Merging [54]
> 
>       Splitting [26]
> 
>       Merging [26]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [54]
> 
> right half after split [26]
> 
>     Merging [26, 54]
> 
>     Splitting [93, 17]
> 
> left half before split  [93]
> 
> right half before split [17]
> 
>       Splitting [93]
> 
>       Merging [93]
> 
>       Splitting [17]
> 
>       Merging [17]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [93]
> 
> right half after split [17]
> 
>     Merging [17, 93]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [26, 54]
> 
> right half after split [17, 93]
> 
>   Merging [17, 26, 54, 93]
> 
>   Splitting [77, 31, 44, 55, 20]
> 
> left half before split  [77, 31]
> 
> right half before split [44, 55, 20]
> 
>     Splitting [77, 31]
> 
> left half before split  [77]
> 
> right half before split [31]
> 
>       Splitting [77]
> 
>       Merging [77]
> 
>       Splitting [31]
> 
>       Merging [31]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [77]
> 
> right half after split [31]
> 
>     Merging [31, 77]
> 
>     Splitting [44, 55, 20]
> 
> left half before split  [44]
> 
> right half before split [55, 20]
> 
>       Splitting [44]
> 
>       Merging [44]
> 
>       Splitting [55, 20]
> 
> left half before split  [55]
> 
> right half before split [20]
> 
>         Splitting [55]
> 
>         Merging [55]
> 
>         Splitting [20]
> 
>         Merging [20]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [55]
> 
> right half after split [20]
> 
>       Merging [20, 55]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [44]
> 
> right half after split [20, 55]
> 
>     Merging [20, 44, 55]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [31, 77]
> 
> right half after split [20, 44, 55]
> 
>   Merging [20, 31, 44, 55, 77]
> 
> 
> 
> HERE AFTER SPLIT
> 
> 
> 
> left half after split [17, 26, 54, 93]
> 
> right half after split [20, 31, 44, 55, 77]
> 
>  Merging [17, 20, 26, 31, 44, 54, 55, 77, 93]
> 
> 
> 
>  after calling main mergesort
> 
> 
> 
> [17, 20, 26, 31, 44, 54, 55, 77, 93]
> 
> -------------------------------------------------------
>  
> In the above output, the control goes to "HERE AFTER SPLIT" after the "Merging" statement which is of-course the last statement in the function.On what condition this is happening.
> 
> Ideally as per my understanding, after the last statement of a function the control should come out of the function. 
> 
> Please correct me if I am wrong here.
> 
> There is something with respect-to functions in python that I am not able to understand.



From rosuav at gmail.com  Thu May 30 08:55:38 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 22:55:38 +1000
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <384a9b8f-40e0-4c8c-b15f-0c96512f67f1@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
	<384a9b8f-40e0-4c8c-b15f-0c96512f67f1@googlegroups.com>
Message-ID: <CAPTjJmrd-NSWRKzWkQ=hJjHuH1mfYY=KJXf8c+M2bmR+GKqU8A@mail.gmail.com>

On Thu, May 30, 2013 at 10:39 PM,  <bhk755 at gmail.com> wrote:
> Chris, Can you please let me know what makes the control of the program code go to  2c after the output "Merging".


It goes like this:

1. [eight element list]
2a. [eight element list]
2b.   1. [four element list]
2b.   2a. [four element list]
2b.   2b.    1. [two element list]
2b.   2b.    2a. [two element list]
2b.   2b.    2b. [two element list]
2b.   2b.    2b.    1. [one element list]
2b.   2b.    2b.    2. [one element list]
2b.   2b.    2b.    3. [one element list]
2b.   2b.    2c. [two element list]
2b.   2b.    3. [two element list]
... etc etc etc ...

Notice how control actually flows from 1, to 2a, to 2b, to 2c, but in
between, it goes back to 1? That's recursion. There are four separate
function calls here, which you can see going down the page. Each time
it gets to step 2b, a whole new "thread" starts, and the previous one
doesn't do anything till the inner one reaches step 3 and finishes.

That's why the indented output can help; eyeball them going down and
you'll see that they don't do anything until the inner one finishes.

ChrisA


From bhk755 at gmail.com  Thu May 30 09:01:02 2013
From: bhk755 at gmail.com (bhk755 at gmail.com)
Date: Thu, 30 May 2013 06:01:02 -0700 (PDT)
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
Message-ID: <4cfe27df-b35c-4c3f-a22c-93b29ee26462@googlegroups.com>


Thanks Chris, Wolfgang and Joshua for your replies. 
------------------------

In step 2b, all the steps from 1 through 3 are executed again (twice). 

Soon, those calls will just output "Splitting" followed by "Merging"; 

and then we go back to 2c. That's why it *seems* that the code goes 

from 3 to 2c. You'll notice that the call depth decreases when this 

happens 

Chris, Can you please let me know what makes the control of the program code go to  2c after the output "Merging". 

Also, please look into the following output for the same program with more print statements, 
---------------------------------------------- 
 before calling main mergesort 
 Splitting [54, 26, 93, 17, 77, 31, 44, 55, 20] 
left half before split  [54, 26, 93, 17] 
right half before split [77, 31, 44, 55, 20] 
  Splitting [54, 26, 93, 17] 
left half before split  [54, 26] 
right half before split [93, 17] 
    Splitting [54, 26] 
left half before split  [54] 
right half before split [26] 
      Splitting [54] 
      Merging [54] 
      Splitting [26] 
      Merging [26] 
HERE AFTER SPLIT 
left half after split [54] 
right half after split [26] 
    Merging [26, 54] 
    Splitting [93, 17] 
left half before split  [93] 
right half before split [17] 
      Splitting [93] 
      Merging [93] 
      Splitting [17] 
      Merging [17] 
HERE AFTER SPLIT 
left half after split [93] 
right half after split [17] 
    Merging [17, 93] 
HERE AFTER SPLIT 
left half after split [26, 54] 
right half after split [17, 93] 
  Merging [17, 26, 54, 93] 
  Splitting [77, 31, 44, 55, 20] 
left half before split  [77, 31] 
right half before split [44, 55, 20] 
    Splitting [77, 31] 
left half before split  [77] 
right half before split [31] 
      Splitting [77] 
      Merging [77] 
      Splitting [31] 
      Merging [31] 
HERE AFTER SPLIT 
left half after split [77] 
right half after split [31] 
    Merging [31, 77] 
    Splitting [44, 55, 20] 
ft half before split  [44] 
ght half before split [55, 20] 
     Splitting [44] 
      Merging [44] 
      Splitting [55, 20] 
eft half before split  [55] 
ight half before split [20] 
       Splitting [55] 
       Merging [55] 
       Splitting [20] 
       Merging [20] 
HERE AFTER SPLIT 
left half after split [55] 
right half after split [20] 
      Merging [20, 55] 
HERE AFTER SPLIT 
left half after split [44] 
right half after split [20, 55] 
    Merging [20, 44, 55] 
HERE AFTER SPLIT 
left half after split [31, 77] 
right half after split [20, 44, 55] 
Merging [20, 31, 44, 55, 77] 
HERE AFTER SPLIT 
left half after split [17, 26, 54, 93] 
right half after split [20, 31, 44, 55, 77] 
 Merging [17, 20, 26, 31, 44, 54, 55, 77, 93] 
 after calling main mergesort 
[17, 20, 26, 31, 44, 54, 55, 77, 93] 
------------------------------------------------------- 
   
In the above output, the control goes to "HERE AFTER SPLIT" after the "Merging" statement which is of-course the last statement in the function.On what condition this is happening. 
Ideally as per my understanding, after the last statement of a function the control should come out of the function. 
Please correct me if I am wrong here. 
There is something with respect-to functions in python that I am not able to understand. 


From bhk755 at gmail.com  Fri May 31 00:53:10 2013
From: bhk755 at gmail.com (bhk755 at gmail.com)
Date: Thu, 30 May 2013 21:53:10 -0700 (PDT)
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
Message-ID: <aee367fa-a20c-47b4-9b32-f0561fbcad28@googlegroups.com>

Got It!!!,  Finally.  Thanks Dave

So, the control goes back to the place after the recursive function is called once the no. of element is equal to one and starts merging after which it will again start to split the remaining items.

Thank you Chris for your multiple explanations. It was also very useful.

One final question, Is there a way to edit the message once it has been posted?


From bhk755 at gmail.com  Fri May 31 00:54:35 2013
From: bhk755 at gmail.com (bhk755 at gmail.com)
Date: Thu, 30 May 2013 21:54:35 -0700 (PDT)
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
References: <921173f3-21e7-46b4-a7b1-86660a3ebc72@googlegroups.com>
Message-ID: <c4d87e99-206c-480b-bf5e-2e1fbaa251eb@googlegroups.com>

Got It!!!,  Finally.  Thanks Dave 

So, the control goes back to the place after the recursive function is called once the no. of element is equal to one and starts merging after which it will again start to split the remaining items. 

Thank you Chris for your multiple explanations.

One final question, Is there a way to edit the message once it has been posted? 


From cs at zip.com.au  Fri May 31 01:43:17 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Fri, 31 May 2013 15:43:17 +1000
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <c4d87e99-206c-480b-bf5e-2e1fbaa251eb@googlegroups.com>
References: <c4d87e99-206c-480b-bf5e-2e1fbaa251eb@googlegroups.com>
Message-ID: <20130531054317.GA48344@cskk.homeip.net>

On 30May2013 21:54, bhk755 at gmail.com <bhk755 at gmail.com> wrote:
| One final question, Is there a way to edit the message once it has been posted? 

Essentially, no. If there's some error in a post, reply to it
yourself with a correction. Transparency is a good thing. Revisionist
history pretty much is not.
-- 
Cameron Simpson <cs at zip.com.au>

Well, it's one louder, isn't it?  It's not ten.  You see, most blokes are
gonna be playing at ten, you're on ten here, all the way up, all the way up,
all the way up, you're on ten on your guitar, where can you go from there?
Where?  Nowhere, exactly.  What we do is, if we need that extra push over the
cliff, you know what we do?  Eleven.  Exactly.  One louder.
        - Nigel Tufnel, _This Is Spinal Tap_


From rosuav at gmail.com  Fri May 31 03:13:17 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 17:13:17 +1000
Subject: Can anyone please help me in understanding the following python
	code
In-Reply-To: <20130531054317.GA48344@cskk.homeip.net>
References: <c4d87e99-206c-480b-bf5e-2e1fbaa251eb@googlegroups.com>
	<20130531054317.GA48344@cskk.homeip.net>
Message-ID: <CAPTjJmokXg6T8_tqfN51Yzy0Z1Z2dHFyLoTSCbQ7-J2+Miws_A@mail.gmail.com>

On Fri, May 31, 2013 at 3:43 PM, Cameron Simpson <cs at zip.com.au> wrote:
> On 30May2013 21:54, bhk755 at gmail.com <bhk755 at gmail.com> wrote:
> | One final question, Is there a way to edit the message once it has been posted?
>
> Essentially, no. If there's some error in a post, reply to it
> yourself with a correction. Transparency is a good thing. Revisionist
> history pretty much is not.

Once your email or newsgroup post is sent, assume that it's also been
received; at very least, you won't be far wrong. You'll sometimes see
a response within minutes from someone who saw your post within
seconds.

ChrisA


From eternaltheft at gmail.com  Thu May 30 07:33:41 2013
From: eternaltheft at gmail.com (Eternaltheft)
Date: Thu, 30 May 2013 04:33:41 -0700 (PDT)
Subject: User Input
Message-ID: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>

Hi, I'm having trouble oh how prompt the user to enter a file name and how to set up conditions. For example, if there's no file name input by the user, a default is returned


From fabiosantosart at gmail.com  Thu May 30 07:45:43 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 30 May 2013 12:45:43 +0100
Subject: User Input
In-Reply-To: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
Message-ID: <CAA=1kxRgGT8D9BU-+4F1rhRauUq38U0YsUeJnPbKeN6uQHZ59Q@mail.gmail.com>

On 30 May 2013 12:42, "Eternaltheft" <eternaltheft at gmail.com> wrote:
>
> Hi, I'm having trouble oh how prompt the user to enter a file name and
how to set up conditions. For example, if there's no file name input by the
user, a default is returned

Are you using raw_input? It returns an empty string if the user enters
nothing, so you can just use an if.

filename = raw_input('file name: ')
if not filename:
    filename = 'your default'
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From eternaltheft at gmail.com  Thu May 30 07:48:56 2013
From: eternaltheft at gmail.com (Eternaltheft)
Date: Thu, 30 May 2013 04:48:56 -0700 (PDT)
Subject: User Input
In-Reply-To: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
Message-ID: <7f9b7a2e-3142-468b-a2ce-9434c1ad7989@googlegroups.com>

On Thursday, May 30, 2013 7:33:41 PM UTC+8, Eternaltheft wrote:
> Hi, I'm having trouble oh how prompt the user to enter a file name and how to set up conditions. For example, if there's no file name input by the user, a default is returned

Thanks for such a fast reply! and no im not using raw input, im just using input. does raw_input work on python 3?


From rosuav at gmail.com  Thu May 30 08:06:41 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 22:06:41 +1000
Subject: User Input
In-Reply-To: <7f9b7a2e-3142-468b-a2ce-9434c1ad7989@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<7f9b7a2e-3142-468b-a2ce-9434c1ad7989@googlegroups.com>
Message-ID: <CAPTjJmoKZUzkR9OZUO2mY0BdwjQYS7YCF0sGo9ABuVohTUSqSA@mail.gmail.com>

On Thu, May 30, 2013 at 9:48 PM, Eternaltheft <eternaltheft at gmail.com> wrote:
> On Thursday, May 30, 2013 7:33:41 PM UTC+8, Eternaltheft wrote:
>> Hi, I'm having trouble oh how prompt the user to enter a file name and how to set up conditions. For example, if there's no file name input by the user, a default is returned
>
> Thanks for such a fast reply! and no im not using raw input, im just using input. does raw_input work on python 3?

No, on Python 3 just use input. In Python 2, input() is a dangerous
function that evaluates the entered text and raw_input() is the safe
one; in Python 3, raw_input got renamed to input(). Go ahead and use
input the way Fabio used raw_input.

By the way, there's a handy compact notation for what Fabio wrote:

filename = raw_input('file name: ') or 'your default'

Can be very handy!

ChrisA


From python at mrabarnett.plus.com  Thu May 30 08:08:25 2013
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 30 May 2013 13:08:25 +0100
Subject: User Input
In-Reply-To: <7f9b7a2e-3142-468b-a2ce-9434c1ad7989@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<7f9b7a2e-3142-468b-a2ce-9434c1ad7989@googlegroups.com>
Message-ID: <51A74139.1020508@mrabarnett.plus.com>

On 30/05/2013 12:48, Eternaltheft wrote:
> On Thursday, May 30, 2013 7:33:41 PM UTC+8, Eternaltheft wrote:
>> Hi, I'm having trouble oh how prompt the user to enter a file name
>> and how to set up conditions. For example, if there's no file name
>> input by the user, a default is returned
>
> Thanks for such a fast reply! and no im not using raw input, im just
> using input. does raw_input work on python 3?
>
In Python 2 it's called "raw_input" and in Python 3 it's called "input".

Python 2 does have a function called "input", but it's not recommended
(it's dangerous because it's equivalent to "eval(raw_input())", which
will evaluate _whatever_ is entered).


From fabiosantosart at gmail.com  Thu May 30 08:10:53 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 30 May 2013 13:10:53 +0100
Subject: User Input
In-Reply-To: <7f9b7a2e-3142-468b-a2ce-9434c1ad7989@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<7f9b7a2e-3142-468b-a2ce-9434c1ad7989@googlegroups.com>
Message-ID: <CAA=1kxSFu_Zy51mPBfukrqH4ux3PJm1sH88evbj_ZSTfVO7spw@mail.gmail.com>

On 30 May 2013 12:58, "Eternaltheft" <eternaltheft at gmail.com> wrote:
>
> On Thursday, May 30, 2013 7:33:41 PM UTC+8, Eternaltheft wrote:
> > Hi, I'm having trouble oh how prompt the user to enter a file name and
how to set up conditions. For example, if there's no file name input by the
user, a default is returned
>
> Thanks for such a fast reply! and no im not using raw input, im just
using input. does raw_input work on python 3?

On python 2, the function to prompt the user for input and return a string
is raw_input.

On python 3 that function has been renamed to input.

However on python 2 input is something else. It also evaluates the input as
a python expression. That makes it unsafe to use in most circumstances.
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From eternaltheft at gmail.com  Thu May 30 08:19:08 2013
From: eternaltheft at gmail.com (Eternaltheft)
Date: Thu, 30 May 2013 05:19:08 -0700 (PDT)
Subject: User Input
In-Reply-To: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
Message-ID: <ccfe68ad-4dbf-4d4f-87ab-5b55d5ca0a26@googlegroups.com>

Ok thanks guys. but when i use 

filename = input('file name: ')
if not filename:      #i get filename is not defined
    return(drawBoard) #possible to return function when no file input from user?



From fabiosantosart at gmail.com  Thu May 30 08:27:29 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Thu, 30 May 2013 13:27:29 +0100
Subject: User Input
In-Reply-To: <ccfe68ad-4dbf-4d4f-87ab-5b55d5ca0a26@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<ccfe68ad-4dbf-4d4f-87ab-5b55d5ca0a26@googlegroups.com>
Message-ID: <CAA=1kxTZ4r0K9RO5Jqnd1H65d2QGaLmNSPMODpZ5jdk6ePUjYQ@mail.gmail.com>

On 30 May 2013 13:24, "Eternaltheft" <eternaltheft at gmail.com> wrote:
>
> Ok thanks guys. but when i use
>
> filename = input('file name: ')
> if not filename:      #i get filename is not defined
>     return(drawBoard) #possible to return function when no file input
from user?

I don't really understand what you mean. Do you mean that you're getting a
stack trace?
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From rosuav at gmail.com  Thu May 30 08:28:39 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 22:28:39 +1000
Subject: User Input
In-Reply-To: <ccfe68ad-4dbf-4d4f-87ab-5b55d5ca0a26@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<ccfe68ad-4dbf-4d4f-87ab-5b55d5ca0a26@googlegroups.com>
Message-ID: <CAPTjJmr0zUwxhz47dyMmdpV53OLGOSFb-ZLWLrs9BtNSUuAPwg@mail.gmail.com>

On Thu, May 30, 2013 at 10:19 PM, Eternaltheft <eternaltheft at gmail.com> wrote:
> Ok thanks guys. but when i use
>
> filename = input('file name: ')
> if not filename:      #i get filename is not defined
>     return(drawBoard) #possible to return function when no file input from user?

Do you really want to return there? What function is this defined in?

I think you probably want what Fabio originally said: that "if not
filename" (which, in this context, means "if the user hit Enter
without typing anything"), assign something to filename.

ChrisA


From eternaltheft at gmail.com  Thu May 30 08:37:31 2013
From: eternaltheft at gmail.com (Eternaltheft)
Date: Thu, 30 May 2013 05:37:31 -0700 (PDT)
Subject: User Input
In-Reply-To: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
Message-ID: <864c9d49-9929-43dd-b484-d6be92564cc3@googlegroups.com>

sorry about that, i got confused xD. yeah it works good now. 
what i meant to say was can i return a function that i made, if the user inputs nothing?


From davea at davea.name  Thu May 30 08:58:32 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 30 May 2013 08:58:32 -0400
Subject: User Input
In-Reply-To: <864c9d49-9929-43dd-b484-d6be92564cc3@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<864c9d49-9929-43dd-b484-d6be92564cc3@googlegroups.com>
Message-ID: <51A74CF8.2030708@davea.name>

On 05/30/2013 08:37 AM, Eternaltheft wrote:
> sorry about that, i got confused xD. yeah it works good now.
> what i meant to say was can i return a function that i made, if the user inputs nothing?
>

There wouldn't be anything to stop you.  However, if you have multiple 
returns from the same function, it's usually wise to return the same 
type of information from each of them.  That's why Chris suggested 
simply assigning to filename in the if clause.

But without the whole function, and maybe even a description of what the 
function is expected to do, we can only guess.

Your comments still make no sense to me,

 > filename = input('file name: ')
 > if not filename:      #i get filename is not defined

But filename IS defined, immediately above. If it were undefined, you'd 
not be able to test it here.  Big difference between "not defined" and 
"is empty string".

 >    return(drawBoard) #possible to return function when no file input 
from user?

If drawBoard is a function object, it's certainly possible to return it. 
  But again, without seeing the rest of the function, and maybe how it's 
intended to be used, I can't confirm whether it makes sense.

-- 
DaveA


From rosuav at gmail.com  Thu May 30 08:59:42 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 22:59:42 +1000
Subject: User Input
In-Reply-To: <864c9d49-9929-43dd-b484-d6be92564cc3@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<864c9d49-9929-43dd-b484-d6be92564cc3@googlegroups.com>
Message-ID: <CAPTjJmqgpxn7TXCAbLSkyAZh1V_z8vy77a2J8rgq5-ZnREJ9tw@mail.gmail.com>

On Thu, May 30, 2013 at 10:37 PM, Eternaltheft <eternaltheft at gmail.com> wrote:
> sorry about that, i got confused xD. yeah it works good now.
> what i meant to say was can i return a function that i made, if the user inputs nothing?

Sure! Anything you want to do, you can do :)

ChrisA


From eternaltheft at gmail.com  Thu May 30 09:10:22 2013
From: eternaltheft at gmail.com (Eternaltheft)
Date: Thu, 30 May 2013 06:10:22 -0700 (PDT)
Subject: User Input
In-Reply-To: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
Message-ID: <2eaa39b8-9e87-402a-b0c0-8c8c5d42fed7@googlegroups.com>

yeah i found out why it wasn't defined before because i tried to put it into a function. 

this is my drawBoard function: 

import turtle as Turtle
Turtle.title("Checkers")
b = 75

def drawBoard(b):

    Turtle.speed(0)

    Turtle.up()

    Turtle.goto(-4 * b, 4 * b)
    Turtle.down()

    for i in range (8):
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)

    for i in range (1):
        Turtle.right(90)
        Turtle.forward(b*2)
        Turtle.right(90)

    for i in range(8):
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)

    for i in range(1):
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)

    for i in range (8):
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)

    for i in range (1):
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)

    for i in range(8):
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)

    for i in range(1):
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)

    for i in range (8):
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)

    for i in range (1):
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)

    for i in range(8):
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)

    for i in range(1):
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)

    for i in range (8):
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)
        Turtle.left(90)
        Turtle.forward(b)

    for i in range (1):
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)

    for i in range(8):
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)
        Turtle.right(90)
        Turtle.forward(b)


drawBoard(b)

Turtle.done()

it draws an 8x8 board table. 

what i initially wanted to do was to return this function if nothing was inputted from the user. i hope that makes more sense :S


From davea at davea.name  Thu May 30 09:37:56 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 30 May 2013 09:37:56 -0400
Subject: User Input
In-Reply-To: <2eaa39b8-9e87-402a-b0c0-8c8c5d42fed7@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<2eaa39b8-9e87-402a-b0c0-8c8c5d42fed7@googlegroups.com>
Message-ID: <51A75634.3080505@davea.name>

On 05/30/2013 09:10 AM, Eternaltheft wrote:
> yeah i found out why it wasn't defined before because i tried to put it into a function.

That's not a sentence, and it doesn't make sense in any permutation I 
can do on it.

>
> this is my drawBoard function:
>
> import turtle as Turtle
> Turtle.title("Checkers")
> b = 75
>
> def drawBoard(b):
>
>      Turtle.speed(0)
>
>      Turtle.up()
>
>      Turtle.goto(-4 * b, 4 * b)
>      Turtle.down()
>
>      for i in range (8):
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>
>      for i in range (1):
>          Turtle.right(90)
>          Turtle.forward(b*2)
>          Turtle.right(90)
>
>      for i in range(8):
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>
>      for i in range(1):
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>
>      for i in range (8):
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>
>      for i in range (1):
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>
>      for i in range(8):
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>
>      for i in range(1):
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>
>      for i in range (8):
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>
>      for i in range (1):
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>
>      for i in range(8):
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>
>      for i in range(1):
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>
>      for i in range (8):
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>          Turtle.left(90)
>          Turtle.forward(b)
>
>      for i in range (1):
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>
>      for i in range(8):
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>          Turtle.right(90)
>          Turtle.forward(b)
>
>
> drawBoard(b)
>
> Turtle.done()
>
> it draws an 8x8 board table.
>
> what i initially wanted to do was to return this function if nothing was inputted from the user. i hope that makes more sense :S
>

It makes sense if you're also returning a function object when the user 
does have something to say.  But I can't see how you might be doing 
that, unless you're using a lambda to make up a custom function object.

And you still don't show us the function that contains this input 
statement.  Nor how it gets used.  Is the user supposed to supply a 
value for b, and you put it in a variable called filename ?

And perhaps you meant for your function to CALL drawBoard(), rather than 
returning the function object drawBoard.

-- 
DaveA


From eternaltheft at gmail.com  Thu May 30 10:03:31 2013
From: eternaltheft at gmail.com (Eternaltheft)
Date: Thu, 30 May 2013 07:03:31 -0700 (PDT)
Subject: User Input
In-Reply-To: <mailman.2422.1369921090.3114.python-list@python.org>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<2eaa39b8-9e87-402a-b0c0-8c8c5d42fed7@googlegroups.com>
	<mailman.2422.1369921090.3114.python-list@python.org>
Message-ID: <e7509760-32bc-41e5-b27f-bc10d2a4c7d8@googlegroups.com>

do you think ti would be better if i call drawBoard?


From davea at davea.name  Thu May 30 10:14:01 2013
From: davea at davea.name (Dave Angel)
Date: Thu, 30 May 2013 10:14:01 -0400
Subject: User Input
In-Reply-To: <e7509760-32bc-41e5-b27f-bc10d2a4c7d8@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<2eaa39b8-9e87-402a-b0c0-8c8c5d42fed7@googlegroups.com>
	<mailman.2422.1369921090.3114.python-list@python.org>
	<e7509760-32bc-41e5-b27f-bc10d2a4c7d8@googlegroups.com>
Message-ID: <51A75EA9.2080204@davea.name>

On 05/30/2013 10:03 AM, Eternaltheft wrote:
> do you think ti would be better if i call drawBoard?
>

Better is meaningless without context.

Are you being charged per keystroke?

-- 
DaveA


From breamoreboy at yahoo.co.uk  Thu May 30 10:30:44 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 30 May 2013 15:30:44 +0100
Subject: User Input
In-Reply-To: <e7509760-32bc-41e5-b27f-bc10d2a4c7d8@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<2eaa39b8-9e87-402a-b0c0-8c8c5d42fed7@googlegroups.com>
	<mailman.2422.1369921090.3114.python-list@python.org>
	<e7509760-32bc-41e5-b27f-bc10d2a4c7d8@googlegroups.com>
Message-ID: <ko7nq3$sff$1@ger.gmane.org>

On 30/05/2013 15:03, Eternaltheft wrote:
> do you think ti would be better if i call drawBoard?
>

How would I know if you don't quote any context?

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From eternaltheft at gmail.com  Thu May 30 10:49:14 2013
From: eternaltheft at gmail.com (Eternaltheft)
Date: Thu, 30 May 2013 07:49:14 -0700 (PDT)
Subject: User Input
In-Reply-To: <mailman.2423.1369924248.3114.python-list@python.org>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<2eaa39b8-9e87-402a-b0c0-8c8c5d42fed7@googlegroups.com>
	<mailman.2422.1369921090.3114.python-list@python.org>
	<e7509760-32bc-41e5-b27f-bc10d2a4c7d8@googlegroups.com>
	<mailman.2423.1369924248.3114.python-list@python.org>
Message-ID: <a0d568c0-7fdf-4694-9993-717494513f74@googlegroups.com>


> And perhaps you meant for your function to CALL drawBoard(), rather than 
> returning the function object drawBoard. 
> DaveA 

do you think it would be better if i call drawBoard? 


From eternaltheft at gmail.com  Thu May 30 10:47:32 2013
From: eternaltheft at gmail.com (Eternaltheft)
Date: Thu, 30 May 2013 07:47:32 -0700 (PDT)
Subject: User Input
In-Reply-To: <mailman.2422.1369921090.3114.python-list@python.org>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<2eaa39b8-9e87-402a-b0c0-8c8c5d42fed7@googlegroups.com>
	<mailman.2422.1369921090.3114.python-list@python.org>
Message-ID: <7064d3fc-7641-4ecd-9fe0-9631e949fe72@googlegroups.com>


> And perhaps you meant for your function to CALL drawBoard(), rather than 
> 
> returning the function object drawBoard.
> 
> DaveA


do you think it would be better if i call drawBoard?




From joshua.landau.ws at gmail.com  Thu May 30 11:09:12 2013
From: joshua.landau.ws at gmail.com (Joshua Landau)
Date: Thu, 30 May 2013 16:09:12 +0100
Subject: User Input
In-Reply-To: <7064d3fc-7641-4ecd-9fe0-9631e949fe72@googlegroups.com>
References: <e3fd9fdd-efa0-45b8-97b9-b77519012640@googlegroups.com>
	<2eaa39b8-9e87-402a-b0c0-8c8c5d42fed7@googlegroups.com>
	<mailman.2422.1369921090.3114.python-list@python.org>
	<7064d3fc-7641-4ecd-9fe0-9631e949fe72@googlegroups.com>
Message-ID: <CAN1F8qWAZUvdO_5Y44TRwj=fBm2TUwZchzCg-rg+Ev84NzEQQQ@mail.gmail.com>

On 30 May 2013 15:47, Eternaltheft <eternaltheft at gmail.com> wrote:
>> And perhaps you meant for your function to CALL drawBoard(), rather than
>> returning the function object drawBoard.
>>
>> DaveA
>
> do you think it would be better if i call drawBoard?

Please read http://www.catb.org/esr/faqs/smart-questions.html, or
anything similar you can find.

Start from the beginning.

1) What are you doing? Not "what are you doing now" but, from the top,
what is the goal you are trying to achieve?

2) How have you tried to do it? Code  would be nice here too, but
don't just send really large blocks of irrelevant code. For example, your
"drawBoard" function would be better surmised as:

def drawBoard(b):
    Turtle.speed(0)
    Turtle.up()
    Turtle.goto(-4 * b, 4 * b)
    Turtle.down()

    for i in range (8):
        Turtle.forward(b)
        Turtle.right(90)
        ... # etc, drawing a board

3) What are you stuck on? In this case, you are stuck on what to do
after you call input("stuff"), if I understand. What do you want to do
- not "how do you want to do it" but what is it that you are doing?

4) Finally, we should understand what calling drawBoard is for. Ask us
again and we'll be much more likely to give good answers.


From nobody at nowhere.org  Thu May 30 08:20:18 2013
From: nobody at nowhere.org (Franck Ditter)
Date: Thu, 30 May 2013 14:20:18 +0200
Subject: Python toplevel in a Web page
Message-ID: <nobody-F6A3A1.14201830052013@news.free.fr>

Hello,
I wonder if I can find some source code example
of a Python 3 toplevel box in a Web page.
Something simple, no mySQL, no Django hammer, etc.
Just the basics of the technology to get the
content of a small text editor in which the user
writes some Python script, to be analyzed (eval'ed)
then whose result is to be written in another text box.
Simple, pythonistic.
Thanks for the pointer,

    franck


From carlosnepomuceno at outlook.com  Thu May 30 17:40:58 2013
From: carlosnepomuceno at outlook.com (Carlos Nepomuceno)
Date: Fri, 31 May 2013 00:40:58 +0300
Subject: Python toplevel in a Web page
In-Reply-To: <nobody-F6A3A1.14201830052013@news.free.fr>
References: <nobody-F6A3A1.14201830052013@news.free.fr>
Message-ID: <BLU176-W17A2A910EB359B790F5FD6D7910@phx.gbl>

----------------------------------------
> From: nobody at nowhere.org
> Subject: Python toplevel in a Web page
> Date: Thu, 30 May 2013 14:20:18 +0200
> To: python-list at python.org
>
> Hello,
> I wonder if I can find some source code example
> of a Python 3 toplevel box in a Web page.
> Something simple, no mySQL, no Django hammer, etc.
> Just the basics of the technology to get the
> content of a small text editor in which the user

Do you mean HTML <textarea> element?

> writes some Python script, to be analyzed (eval'ed)
> then whose result is to be written in another text box.

Analyzed by the browser or server side?

> Simple, pythonistic.
> Thanks for the pointer,
>
> franck
> --
> http://mail.python.org/mailman/listinfo/python-list 		 	   		  

From support at superhost.gr  Thu May 30 08:25:53 2013
From: support at superhost.gr (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Thu, 30 May 2013 05:25:53 -0700 (PDT)
Subject: Is this code correct?
Message-ID: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>

#!/usr/bin/python3
# coding=utf-8

import cgitb; cgitb.enable()
import cgi, os, sys
from http import cookies

# initialize cookie
cookie = cookies.SimpleCookie( os.environ.get('HTTP_COOKIE') )
cookie.load( cookie )
nikos = cookie.get('nikos')

# if visitor cookie does exist
if nikos:
	msg = "??? ??? ??????? ???????? ??? ?? ?? ????????? ?? ????????? ?????????? ??? ???????!"
	cookie['nikos'] = 'admin'
	cookie['nikos']['path'] = '/'
	cookie['nikos']['expires'] = -1		#this cookie will expire now
else:
	msg = "??? ?? ??? ??? ???? ??? ?? ????, ??? ?? ????, ??? ?? ??????! ?? ????? ????? ? ??????? ??????????!!"
	cookie['nikos'] = 'admin'
	cookie['nikos']['path'] = '/'
	cookie['nikos']['expires'] = 60*60*24*30*12		#this cookie will expire in a year


#needed line, script does *not* work without it
sys.stdout = os.fdopen(1, 'w', encoding='utf-8')

print( cookie )
print ( "Content-type: text/html; charset=utf-8\n" )
print( msg )

sys.exit(0)


From rosuav at gmail.com  Thu May 30 08:34:09 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 22:34:09 +1000
Subject: Is this code correct?
In-Reply-To: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
References: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
Message-ID: <CAPTjJmrDCbBqXSs8mztZ+yQWwE-LKgvJWOug0s-b3dA9szn4vQ@mail.gmail.com>

On Thu, May 30, 2013 at 10:25 PM, ????? ???33? <support at superhost.gr> wrote:
> #!/usr/bin/python3
> # coding=utf-8
> (chomp a whole lot of code without any indication of what it ought to do)

Why not run it and see? If it does what it ought to, it's correct; if
it does something different, it's not. Why do you expect us to do your
basic testing for you?

ChrisA


From support at superhost.gr  Thu May 30 08:31:06 2013
From: support at superhost.gr (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Thu, 30 May 2013 05:31:06 -0700 (PDT)
Subject: Is this code correct?
In-Reply-To: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
References: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
Message-ID: <6c380793-6f1f-4d5c-9a55-dcb21079511a@googlegroups.com>

This is my last question, everythign else is taken care of.

i cant test thjis coe online because i receive this

[Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] suexec failure: could not open log file
[Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] fopen: Permission denied
[Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py
[Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] File does not exist: /home/nikos/public_html/500.shtml

when i tail -F /usr/local/apache/logs/error_log &

maybe it is correct but it wont run, perhaps somethign with linux?


From rosuav at gmail.com  Thu May 30 08:59:21 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 22:59:21 +1000
Subject: Is this code correct?
In-Reply-To: <6c380793-6f1f-4d5c-9a55-dcb21079511a@googlegroups.com>
References: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
	<6c380793-6f1f-4d5c-9a55-dcb21079511a@googlegroups.com>
Message-ID: <CAPTjJmoExZGBJAROagaDwRyut3Eh=ofMqnHb+OH4PpAFQX1f1g@mail.gmail.com>

On Thu, May 30, 2013 at 10:31 PM, ????? ???33? <support at superhost.gr> wrote:
> This is my last question, everythign else is taken care of.
>
> i cant test thjis coe online because i receive this
>
> [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] suexec failure: could not open log file
> [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] fopen: Permission denied
> [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py
> [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] File does not exist: /home/nikos/public_html/500.shtml
>
> when i tail -F /usr/local/apache/logs/error_log &
>
> maybe it is correct but it wont run, perhaps somethign with linux?

I don't know, why not ask on a Linux mailing list? Or have you run
them out of patience too?

ChrisA


From support at superhost.gr  Thu May 30 09:03:56 2013
From: support at superhost.gr (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Thu, 30 May 2013 06:03:56 -0700 (PDT)
Subject: Is this code correct?
In-Reply-To: <mailman.2417.1369918764.3114.python-list@python.org>
References: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
	<6c380793-6f1f-4d5c-9a55-dcb21079511a@googlegroups.com>
	<mailman.2417.1369918764.3114.python-list@python.org>
Message-ID: <8aa9684c-fda6-4549-ac1e-764b815f2f45@googlegroups.com>

?? ??????, 30 ????? 2013 3:59:21 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
> On Thu, May 30, 2013 at 10:31 PM, ????? ???33? <support at superhost.gr> wrote:
> 
> > This is my last question, everythign else is taken care of.
> 
> >
> 
> > i cant test thjis coe online because i receive this
> 
> >
> 
> > [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] suexec failure: could not open log file
> 
> > [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] fopen: Permission denied
> 
> > [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py
> 
> > [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] File does not exist: /home/nikos/public_html/500.shtml
> 
> >
> 
> > when i tail -F /usr/local/apache/logs/error_log &
> 
> >
> 
> > maybe it is correct but it wont run, perhaps somethign with linux?
> 
> 
> 
> I don't know, why not ask on a Linux mailing list? Or have you run
> 
> them out of patience too?
> 
> 
> 
> ChrisA

I though you guys might know because you "do" linux as well.

i tried chown "nikos:nikos ./koukos.py" but doenst do the job either.


From breamoreboy at yahoo.co.uk  Thu May 30 09:05:00 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 30 May 2013 14:05:00 +0100
Subject: Is this code correct?
In-Reply-To: <6c380793-6f1f-4d5c-9a55-dcb21079511a@googlegroups.com>
References: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
	<6c380793-6f1f-4d5c-9a55-dcb21079511a@googlegroups.com>
Message-ID: <ko7ipa$m9k$1@ger.gmane.org>

On 30/05/2013 13:31, ????? ???33? wrote:
> This is my last question, everythign else is taken care of.
>
> i cant test thjis coe online because i receive this
>
> [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] suexec failure: could not open log file
> [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] fopen: Permission denied
> [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] Premature end of script headers: koukos.py
> [Thu May 30 15:29:33 2013] [error] [client 46.12.46.11] File does not exist: /home/nikos/public_html/500.shtml
>
> when i tail -F /usr/local/apache/logs/error_log &
>
> maybe it is correct but it wont run, perhaps somethign with linux?
>

Please ask questions unrelated to Python on a list that is unrelated to 
Python.

-- 
If you're using GoogleCrap? please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence



From rosuav at gmail.com  Thu May 30 09:36:11 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 30 May 2013 23:36:11 +1000
Subject: Is this code correct?
In-Reply-To: <ko7ipa$m9k$1@ger.gmane.org>
References: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
	<6c380793-6f1f-4d5c-9a55-dcb21079511a@googlegroups.com>
	<ko7ipa$m9k$1@ger.gmane.org>
Message-ID: <CAPTjJmqdFtwFOTZfYDqb6xyXaCg4eYtWNGnWgEF+MzXzTVJXJg@mail.gmail.com>

On Thu, May 30, 2013 at 11:05 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> Please ask questions unrelated to Python on a list that is unrelated to
> Python.

Lemme guess, he's next going to ask on the PostgreSQL mailing list. I
mean, that's unrelated to Python, right?

ChrisA


From support at superhost.gr  Thu May 30 09:45:08 2013
From: support at superhost.gr (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Thu, 30 May 2013 06:45:08 -0700 (PDT)
Subject: Is this code correct?
In-Reply-To: <mailman.2421.1369920973.3114.python-list@python.org>
References: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
	<6c380793-6f1f-4d5c-9a55-dcb21079511a@googlegroups.com>
	<ko7ipa$m9k$1@ger.gmane.org>
	<mailman.2421.1369920973.3114.python-list@python.org>
Message-ID: <1c0db5c4-7a76-4a64-977a-b0261fda1587@googlegroups.com>

?? ??????, 30 ????? 2013 4:36:11 ?.?. UTC+3, ? ??????? Chris Angelico ??????:

> Lemme guess, he's next going to ask on the PostgreSQL mailing list. I
> mean, that's unrelated to Python, right?

Well Chris, i'am not that stupid :)

I intend to ask questions unrelated to Python to a list unrelated to Python but related to my subject, whish is 'suexec', that would mean a linux list.


From cs at zip.com.au  Fri May 31 19:46:31 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Sat, 1 Jun 2013 09:46:31 +1000
Subject: Is this code correct?
In-Reply-To: <1c0db5c4-7a76-4a64-977a-b0261fda1587@googlegroups.com>
References: <1c0db5c4-7a76-4a64-977a-b0261fda1587@googlegroups.com>
Message-ID: <20130531234631.GA62084@cskk.homeip.net>

On 30May2013 06:45, Nikos as SuperHost Support <support at superhost.gr> wrote:
| ?? ??????, 30 ????? 2013 4:36:11 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
| > Lemme guess, he's next going to ask on the PostgreSQL mailing list. I
| > mean, that's unrelated to Python, right?
| 
| Well Chris, i'am not that stupid :)
| 
| I intend to ask questions unrelated to Python to a list unrelated to Python but related to my subject, whish is 'suexec', that would mean a linux list.

Actually, you need an apache httpd list for suexec. It is part of
the web server CGI implementation.
-- 
Cameron Simpson <cs at zip.com.au>


From support at superhost.gr  Thu May 30 09:30:47 2013
From: support at superhost.gr (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Thu, 30 May 2013 06:30:47 -0700 (PDT)
Subject: Is this code correct?
In-Reply-To: <mailman.2419.1369919108.3114.python-list@python.org>
References: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
	<6c380793-6f1f-4d5c-9a55-dcb21079511a@googlegroups.com>
	<mailman.2419.1369919108.3114.python-list@python.org>
Message-ID: <cdaa9f8d-2416-4e7e-acb4-60e19008aa0d@googlegroups.com>

?? ??????, 30 ????? 2013 4:05:00 ?.?. UTC+3, ? ??????? Mark Lawrence ??????:

> Please ask questions unrelated to Python on a list that is unrelated to 
> Python.

Okey, i will.


From support at superhost.gr  Thu May 30 08:54:06 2013
From: support at superhost.gr (=?ISO-8859-7?B?zd/q7/Igw+rxMzPq?=)
Date: Thu, 30 May 2013 05:54:06 -0700 (PDT)
Subject: Is this code correct?
In-Reply-To: <mailman.2413.1369917253.3114.python-list@python.org>
References: <95c02d4f-1d3b-45a9-8b22-1eb7cebafe1b@googlegroups.com>
	<mailman.2413.1369917253.3114.python-list@python.org>
Message-ID: <b0fdafed-1b9d-4222-8b5e-8f78b3dc5043@googlegroups.com>

?? ??????, 30 ????? 2013 3:34:09 ?.?. UTC+3, ? ??????? Chris Angelico ??????:
> On Thu, May 30, 2013 at 10:25 PM, ????? ???33? <support at superhost.gr> wrote:
> 
> > #!/usr/bin/python3
> 
> > # coding=utf-8
> 
> > (chomp a whole lot of code without any indication of what it ought to do)
> 
> 
> 
> Why not run it and see? If it does what it ought to, it's correct; if
> 
> it does something different, it's not. Why do you expect us to do your
> 
> basic testing for you?
> 
> 
> 
> ChrisA

But i cannot test it locally, i just write the code upload it on my remote server and run it from there. But h=this doenst seem to be a python issue, if it is ill correct it myself, it says somehtign about some suexec....


From sanjaybwaj at gmail.com  Thu May 30 11:31:34 2013
From: sanjaybwaj at gmail.com (sanjaybwaj at gmail.com)
Date: Thu, 30 May 2013 08:31:34 -0700 (PDT)
Subject: [ANN] pyknon: Simple Python library to generate music in a hacker
	friendly way.
In-Reply-To: <mailman.2740.1343671881.4697.python-list@python.org>
References: <mailman.2740.1343671881.4697.python-list@python.org>
Message-ID: <d15b572f-65e1-4808-9696-e4eec3d0b4d1@googlegroups.com>

Thanks a lot, Sir. Just what I was looking for. This is a fantastic library for python.


From werotizy at freent.dd  Thu May 30 12:49:48 2013
From: werotizy at freent.dd (Tom P)
Date: Thu, 30 May 2013 18:49:48 +0200
Subject: Google App Engine dev_appserver and pdb?
Message-ID: <b0pe9cF6d9gU1@mid.individual.net>

Is there a way to use pdb to debug Google apps written in Python?
When I start the development system to run the app "test" like this -

'./google_appengine/dev_appserver.py' './test'

  - I'd like to send the program into debug. I couldn't see anything in 
the documentation how to do this. If I do this -
python -mpdb './google_appengine/dev_appserver.py' './test'
  - then dev_appserver.py goes into debug but doesn't know anything 
about "test".



From biolord9 at gmail.com  Thu May 30 13:12:39 2013
From: biolord9 at gmail.com (Thrinaxodon)
Date: Thu, 30 May 2013 10:12:39 -0700 (PDT)
Subject: THRINAXODON BURTS AN AXON!
Message-ID: <65a5a4aa-8fbe-4134-9cbf-bc5e5bedb118@h5g2000vbg.googlegroups.com>

THRINAXODON HAS JUST ENTERED THE WORLD OF REASON-RALLY. SUCH WILD
BEASTS AS PETER NYIKOS, PZ MYERS, RICHARD DAWKINS, DR. EVIL, JOHN S.
WILKINS, JERRY COYNE, MARK ISAAK, SKYEYES, BUDIKKA666, FIDEL TUBARE,
SBAELNAVE, BOB CASANOVA, JOHN HARSHMAN, DAVID IAIN GREIG, AND JILLERY
WERE THERE. THEY WERE MISREPRESENTING, AND DISTORTING THE TRUTH!!!
THRINAXODON REPORTS THIS LIVE.

==============================================

Thrinaxodon scaring this guy, to DEATH.
http://www.youtube.com/watch?v=9Zlzin6PIo8
________________________________________________________
==================================================
Thrinaxodon, in the form of prion, infecting this person's temporal
lobe, and causing DEATH SLOWLY!!!!
http://upload.wikimedia.org/wikipedia/commons/thumb/2/2e/CJD_spongios...
___________________________________________________________________________
___________
YE EVILUTIONISTS, THEY INFECT THE SOUL< AND GIVE YOU NIGHTMARES. THEY
GIVE YOU...
EVVVVVVVVVVVVVVVVVVVVVVVOOOOOOOOOOOOOOOOOOLUTIONIST"S DESEASE!
___________________________________________________________________________
_____________
PROOF OF LIFE AFTER DEATH
http://media.tumblr.com/tumblr_lxlws5u4tE1qjlz5q.jpg
___________________________________________________________________________
__________________
===========================================================================
=============
THRINAXODON KILLS A RABBIT WITH A COUPLE OTHER PEOPLE
http://upload.wikimedia.org/wikipedia/commons/7/74/La_Chasse_au_furet...
===========================================================================


From wolfgang.maier at biologie.uni-freiburg.de  Thu May 30 13:54:12 2013
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Thu, 30 May 2013 17:54:12 +0000 (UTC)
Subject: usage of =?utf-8?b?b3MucG9zaXhfZmFkdmlzZQ==?=
Message-ID: <loom.20130530T193346-17@post.gmane.org>

Antoine Pitrou wrote:

>Hi,

>Wolfgang Maier <wolfgang.maier <at> biologie.uni-freiburg.de> writes:
>> 
>> Dear all,
>> I was just experimenting for the first time with os.posix_fadvise(), which
>> is new in Python3.3 . I'm reading from a really huge file (several GB) and I
>> want to use the data only once, so I don't want OS-level page caching. I
>> tried os.posix_fadvise with the os.POSIX_FADV_NOREUSE and with the
>> os.POSIX_FADV_DONTNEED flags, but neither seemed to have any effect on the
>> caching behaviour of Ubuntu (still uses all available memory to page cache
>> my I/O).
>> Specifically, I was trying this:
>> 
>> import os
>> fd = os.open('myfile', os.O_RDONLY)
>> # wasn't sure about the len parameter in fadvise,
>> # so thought I just use it on the first 4GB
>> os.posix_fadvise(fd, 0, 4000000000, os.POSIX_FADV_NOREUSE) # or DONTNEED
>
>The Linux version of "man posix_fadvise" probably holds the answer:
>
>"In kernels before 2.6.18, POSIX_FADV_NOREUSE had the same semantics
>as POSIX_FADV_WILLNEED.  This was probably a bug; since kernel
>2.6.18, this flag is a no-op."
>
>"POSIX_FADV_DONTNEED attempts to free cached pages associated with the
>specified region.  This is useful, for example, while streaming large
>files.  A program may periodically request the kernel to free cached
>data that has already been used, so that more useful cached pages  are
>not discarded instead."
>
>So, in summary:
>
>- POSIX_FADV_NOREUSE doesn't do anything on (modern) Linux kernels
>- POSIX_FADV_DONTNEED must be called *after* you are done with a range of
>  data, not before you read it (note that I haven't tested to confirm it >:-))
>
>Regards
>
>Antoine.

Hi Antoine,
you're right and thanks a lot for this great piece of information.
The following quick check works like a charm now:

>>> fo = open('myfile', 'rb')
>>> chunk_size = 16184
>>> last_flush = 0
>>> d = fo.read(chunk_size)
>>> pos = chunk_size
>>> while d:
... 	d = fo.read(chunk_size)
... 	pos += chunk_size
... 	if pos > 2000000000:
... 		print ('another 2GB read, flushing')
... 		os.posix_fadvise(fo.fileno(), last_flush, last_flush+pos,
os.POSIX_FADV_DONTNEED)
... 		last_flush += pos
...             pos = 0

With this page caching for my huge file (30 GB in that case) still occurs,
of course, but it never occupies more than 2 GB of memory. This way it
should interfere less with cached data of other applications.
Have to test carefully how much that improves overall performance of the
system, but for the moment I'm more than happy!
Best wishes,
Wolfgang

P.S.: Maybe these new os module features could use a bit more documentation? 



From cs at zip.com.au  Thu May 30 19:21:42 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Fri, 31 May 2013 09:21:42 +1000
Subject: usage of os.posix_fadvise
In-Reply-To: <loom.20130530T193346-17@post.gmane.org>
References: <loom.20130530T193346-17@post.gmane.org>
Message-ID: <20130530232142.GA82658@cskk.homeip.net>

On 30May2013 17:54, Wolfgang Maier <wolfgang.maier at biologie.uni-freiburg.de> wrote:
| Antoine Pitrou wrote:
| >The Linux version of "man posix_fadvise" probably holds the answer:
[...]
| 
| Hi Antoine,
| you're right and thanks a lot for this great piece of information.
[...]
| P.S.: Maybe these new os module features could use a bit more documentation? 

This suggestion comes up a lot WRT to the os.* functions. Unfortunately,
the required doco for your issue is very platform dependent as
you've just discovered; not merely your distro but the very kernel
revisions.

Maybe it should be made much more obvious that users _must_ go and
consult their platform's documentation for specifics on how their
platform implents the interface. On UNIX, that means "man 2 blah"
or "man 3 blah", depending.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

I suppose the solution would be to close the composition window and let
my article sit for half an hour or so once I've finished with it, and
then go back and proofread it once more.  But that would be a pain in
the proverbial bifurcated derriere.  Part of the experience of flaming is
to load a searing missive into the conceptual breech of my SPARCcannon
and pull the imaginary lanyard whilst flushed with the adrenaline of mortal
combat.
        - Geoff Miller, <geoffm at purplehaze.Corp.Sun.COM>


From sokovic.anamarija at gmail.com  Thu May 30 14:14:36 2013
From: sokovic.anamarija at gmail.com (Ana Marija Sokovic)
Date: Thu, 30 May 2013 18:14:36 +0000 (UTC)
Subject: Python and GIL
Message-ID: <loom.20130530T200750-839@post.gmane.org>

Hi,

Can somebody explain to me how would you proceed in releasing the GIL and
whether you think it will have consequences?

Thanks
Ana



From rosuav at gmail.com  Thu May 30 14:30:49 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 31 May 2013 04:30:49 +1000
Subject: Python and GIL
In-Reply-To: <loom.20130530T200750-839@post.gmane.org>
References: <loom.20130530T200750-839@post.gmane.org>
Message-ID: <CAPTjJmq=nXAJPAD+LOKgQCX5Eyvu0g0AtXg-vmeDCJRgsJ=t_A@mail.gmail.com>

On Fri, May 31, 2013 at 4:14 AM, Ana Marija Sokovic
<sokovic.anamarija at gmail.com> wrote:
> Hi,
>
> Can somebody explain to me how would you proceed in releasing the GIL and
> whether you think it will have consequences?

You release the GIL in C-level code when you don't need to work with
Python objects for a while. Simple example is when you need to wait
for something - for instance, if you attempt to read from a pipe, you
can release the GIL before reading, then reacquire it afterward. The
consequence is that you can't do anything with Python objects till you
reacquire it. It's like any other resource-guarding mutex lock.

ChrisA


From steve+comp.lang.python at pearwood.info  Thu May 30 15:41:07 2013
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: 30 May 2013 19:41:07 GMT
Subject: Python and GIL
References: <mailman.2440.1369938013.3114.python-list@python.org>
Message-ID: <51a7ab53$0$29966$c3e8da3$5496439d@news.astraweb.com>

On Thu, 30 May 2013 18:14:36 +0000, Ana Marija Sokovic wrote:

> Hi,
> 
> Can somebody explain to me how would you proceed in releasing the GIL
> and whether you think it will have consequences?

In pure Python code, you don't need to worry about the GIL, and in fact 
you cannot control it. Python controls it.

You only need to release the GIL when writing C extensions. 


-- 
Steven


From wmegchelenbrink at gmail.com  Thu May 30 14:56:25 2013
From: wmegchelenbrink at gmail.com (Wout Megchelenbrink)
Date: Thu, 30 May 2013 11:56:25 -0700 (PDT)
Subject: OpenMP uses only 1 core as soon as numpy is loaded
Message-ID: <76c78a17-c36b-477d-9e1c-576151d8275c@googlegroups.com>

I use openMp in a C-extension that has an interface with Python. 

In its simplest form I do this:

== code ==
	#pragma omp parallel
	{

		#pragma omp for
		for(int i=0; i<10; i++)
		{
                 // multiply some matrices in C 
                 }
       }

== end of code ==


This all works fine, and it uses the number of cores I have. But if I import numpy in my python session BEFORE I run the code, then it uses only 1 core (and omp_num_procs also returns 1 core, instead of the maximum of 8 cores).

So how does numpy affect openMp, and does it have anything to do with the GIL or something? I don't use any Python object in my parallel region.

Any help would be appreciated!
Wout


From skip at pobox.com  Thu May 30 16:46:41 2013
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 30 May 2013 15:46:41 -0500
Subject: Surprising difference between StringIO.StringIO and io.StringIO
Message-ID: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>

Consider this quick session (Python 2.7 using the tip of the 2.7
branch in Mercurial):

% python2.7
Python 2.7.5+ (2.7:93eb15779050, May 30 2013, 15:27:39)
[GCC 4.4.6 [TWW]] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import traceback
>>>
>>> import StringIO
>>> s1 = StringIO.StringIO()
>>> traceback.print_stack(file=s1)
>>> print s1.getvalue()
  File "<stdin>", line 1, in <module>

>>>
>>> import io
>>> s2 = io.StringIO()
>>> traceback.print_stack(file=s2)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/skipm/x86_64-linux3.1/lib/python2.7/traceback.py", line
269, in print_stack
    print_list(extract_stack(f, limit), file)
  File "/home/skipm/x86_64-linux3.1/lib/python2.7/traceback.py", line
23, in print_list
    '  File "%s", line %d, in %s' % (filename,lineno,name))
  File "/home/skipm/x86_64-linux3.1/lib/python2.7/traceback.py", line
13, in _print
    file.write(str+terminator)
TypeError: unicode argument expected, got 'str'
>>> print s2.getvalue()

What is it about io.StringIO that it doesn't like strings and requires
Unicode?  This is on an OpenSUSE 12.1 system.  I have tried with LANG
set to the default ("en_US.UTF-8") and to "C".  I also tried on a
Solaris system with an older micro revision of Python 2.7.  Same
result.

Am I missing something about how io.StringIO works?  I thought it was
a more-or-less drop-in replacement for StringIO.StringIO.

Thx,

Skip


From cs at zip.com.au  Thu May 30 19:15:19 2013
From: cs at zip.com.au (Cameron Simpson)
Date: Fri, 31 May 2013 09:15:19 +1000
Subject: Surprising difference between StringIO.StringIO and io.StringIO
In-Reply-To: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>
References: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>
Message-ID: <20130530231519.GA77870@cskk.homeip.net>

On 30May2013 15:46, Skip Montanaro <skip at pobox.com> wrote:
| Consider this quick session (Python 2.7 using the tip of the 2.7
| branch in Mercurial):
| 
| % python2.7
| Python 2.7.5+ (2.7:93eb15779050, May 30 2013, 15:27:39)
| [GCC 4.4.6 [TWW]] on linux2
[...]
| >>> import io
| >>> s2 = io.StringIO()
[...]
|   File "/home/skipm/x86_64-linux3.1/lib/python2.7/traceback.py", line
| 13, in _print
|     file.write(str+terminator)
| TypeError: unicode argument expected, got 'str'
| >>> print s2.getvalue()
| 
| What is it about io.StringIO that it doesn't like strings and requires
| Unicode?  This is on an OpenSUSE 12.1 system.  I have tried with LANG
| set to the default ("en_US.UTF-8") and to "C".  I also tried on a
| Solaris system with an older micro revision of Python 2.7.  Same
| result.
| 
| Am I missing something about how io.StringIO works?  I thought it was
| a more-or-less drop-in replacement for StringIO.StringIO.

I would expect io.StringIO to be a match for the io.* stuff in Python
3. So it should care whether it is a binary stream or a text stream.
Whereas StringIO.StringIO is your good old Python 2 StringIO, which expects
strs.

On that basis, io.StringIO is a text stream, expecting Unicode
objects for transcription. 'str' is, in that context, probably
considered as 'bytes' in Python 3.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

A ship in harbor is safe - but that is not what ships are for.  - John A. Shedd


From skip at pobox.com  Thu May 30 19:43:08 2013
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 30 May 2013 18:43:08 -0500
Subject: Surprising difference between StringIO.StringIO and io.StringIO
In-Reply-To: <20130530231519.GA77870@cskk.homeip.net>
References: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>
	<20130530231519.GA77870@cskk.homeip.net>
Message-ID: <CANc-5UwFdhY26JMvbixOGZgj0RsLwE42warX54ni3heYwN4hZQ@mail.gmail.com>

>
> I would expect io.StringIO to be a match for the io.* stuff in Python
> 3. So it should care whether it is a binary stream or a text stream.
> Whereas StringIO.StringIO is your good old Python 2 StringIO, which expects
> strs.
>
> On that basis, io.StringIO is a text stream, expecting Unicode
> objects for transcription. 'str' is, in that context, probably
> considered as 'bytes' in Python 3.
>

Thanks.  This example was based on a function in Matplotlib. It appears the
author switched from StringIO.StringIO to io.StringIO between 1.1 and 1.2.

Skip
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From goktug.kayaalp at gmail.com  Thu May 30 19:09:05 2013
From: goktug.kayaalp at gmail.com (=?UTF-8?B?R8O2a3R1xJ8gS2F5YWFscA==?=)
Date: Fri, 31 May 2013 02:09:05 +0300
Subject: Surprising difference between StringIO.StringIO and io.StringIO
In-Reply-To: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>
References: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>
Message-ID: <CAJ6jBQq4GB7m3HbOAtLQuQnPcu+eMtA3WdD2v68SLj0mnifpxQ@mail.gmail.com>

io.StringIO only accepts Unicode input (i.e. u"multibyte string"),
while StringIO.StringIO accepts either 8 bit input or unicode input.
As you can see in the following excerpt from your traceback, the
'print_list' function creates an 8-bit string, which is then
(probably) passed to 'file.write' as the str variable, which actually
expects a unicode string, resulting in a TypeError:

File "/home/skipm/x86_64-linux3.1/lib/python2.7/traceback.py", line
23, in print_list
    '  File "%s", line %d, in %s' % (filename,lineno,name))
File "/home/skipm/x86_64-linux3.1/lib/python2.7/traceback.py", line
13, in _print
    file.write(str+terminator)

Python 2.x strings default to 8 bit. This is fixed (!) in Python 3.
I'd suggest switching to Python 3 if there is no reason to use 2.x. I
found this [*] little PDF back when I switched from 2 to 3, which was
helpful.

[*] http://ptgmedia.pearsoncmg.com/imprint_downloads/informit/promotions/python/python2python3.pdf

Greetings,

        G?ktu?.

On Thu, May 30, 2013 at 11:46 PM, Skip Montanaro <skip at pobox.com> wrote:
> Consider this quick session (Python 2.7 using the tip of the 2.7
> branch in Mercurial):
>
> % python2.7
> Python 2.7.5+ (2.7:93eb15779050, May 30 2013, 15:27:39)
> [GCC 4.4.6 [TWW]] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import traceback
>>>>
>>>> import StringIO
>>>> s1 = StringIO.StringIO()
>>>> traceback.print_stack(file=s1)
>>>> print s1.getvalue()
>   File "<stdin>", line 1, in <module>
>
>>>>
>>>> import io
>>>> s2 = io.StringIO()
>>>> traceback.print_stack(file=s2)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "/home/skipm/x86_64-linux3.1/lib/python2.7/traceback.py", line
> 269, in print_stack
>     print_list(extract_stack(f, limit), file)
>   File "/home/skipm/x86_64-linux3.1/lib/python2.7/traceback.py", line
> 23, in print_list
>     '  File "%s", line %d, in %s' % (filename,lineno,name))
>   File "/home/skipm/x86_64-linux3.1/lib/python2.7/traceback.py", line
> 13, in _print
>     file.write(str+terminator)
> TypeError: unicode argument expected, got 'str'
>>>> print s2.getvalue()
>
> What is it about io.StringIO that it doesn't like strings and requires
> Unicode?  This is on an OpenSUSE 12.1 system.  I have tried with LANG
> set to the default ("en_US.UTF-8") and to "C".  I also tried on a
> Solaris system with an older micro revision of Python 2.7.  Same
> result.
>
> Am I missing something about how io.StringIO works?  I thought it was
> a more-or-less drop-in replacement for StringIO.StringIO.
>
> Thx,
>
> Skip
> --
> http://mail.python.org/mailman/listinfo/python-list


From storchaka at gmail.com  Fri May 31 05:39:41 2013
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Fri, 31 May 2013 12:39:41 +0300
Subject: Surprising difference between StringIO.StringIO and io.StringIO
In-Reply-To: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>
References: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>
Message-ID: <ko9r4m$a1c$1@ger.gmane.org>

30.05.13 23:46, Skip Montanaro ???????(??):
> Am I missing something about how io.StringIO works?  I thought it was
> a more-or-less drop-in replacement for StringIO.StringIO.

io.StringIO was backported from Python 3. It is a text (unicode) stream. 
cStringIO.StringIO is a binary stream and StringIO.StringIO can be used 
as binary or unicode stream depending on arguments. Use io.BaseIO as a 
replacement for StringIO.StringIO/cStringIO.StringIO if you need a 
binary stream.




From __peter__ at web.de  Fri May 31 05:55:37 2013
From: __peter__ at web.de (Peter Otten)
Date: Fri, 31 May 2013 11:55:37 +0200
Subject: Surprising difference between StringIO.StringIO and io.StringIO
References: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>
	<ko9r4m$a1c$1@ger.gmane.org>
Message-ID: <ko9s26$imp$2@ger.gmane.org>

Serhiy Storchaka wrote:

> 30.05.13 23:46, Skip Montanaro ???????(??):
>> Am I missing something about how io.StringIO works?  I thought it was
>> a more-or-less drop-in replacement for StringIO.StringIO.
> 
> io.StringIO was backported from Python 3. It is a text (unicode) stream.
> cStringIO.StringIO is a binary stream and StringIO.StringIO can be used
> as binary or unicode stream depending on arguments. Use io.BaseIO as a

I think you mean io.BytesIO.

> replacement for StringIO.StringIO/cStringIO.StringIO if you need a
> binary stream.




From storchaka at gmail.com  Fri May 31 06:35:38 2013
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Fri, 31 May 2013 13:35:38 +0300
Subject: Surprising difference between StringIO.StringIO and io.StringIO
In-Reply-To: <ko9s26$imp$2@ger.gmane.org>
References: <CANc-5UyDZ=ArzKrs=Y9CDwNwOunDt3DGpy5KKATZ_R=Z-LsHtA@mail.gmail.com>
	<ko9r4m$a1c$1@ger.gmane.org> <ko9s26$imp$2@ger.gmane.org>
Message-ID: <ko9udi$bba$1@ger.gmane.org>

31.05.13 12:55, Peter Otten ???????(??):
> Serhiy Storchaka wrote:
>
>> 30.05.13 23:46, Skip Montanaro ???????(??):
>>> Am I missing something about how io.StringIO works?  I thought it was
>>> a more-or-less drop-in replacement for StringIO.StringIO.
>>
>> io.StringIO was backported from Python 3. It is a text (unicode) stream.
>> cStringIO.StringIO is a binary stream and StringIO.StringIO can be used
>> as binary or unicode stream depending on arguments. Use io.BaseIO as a
>
> I think you mean io.BytesIO.

Indead, thank you for correction.

>> replacement for StringIO.StringIO/cStringIO.StringIO if you need a
>> binary stream.
>
>




From chitrankdixit at gmail.com  Thu May 30 22:21:53 2013
From: chitrankdixit at gmail.com (Chitrank Dixit)
Date: Fri, 31 May 2013 07:51:53 +0530
Subject: How to Begin Web Development with Python ?
Message-ID: <CAH7uNX2kUEcLd4zF1g=Wk35Are_vG-BtD4fgvCey4TM8JuPHog@mail.gmail.com>

Hello Python developers

I have learnt python and used it for various purposes for scietific
computing using sage and GUI development using Tkinter and lots more. I
want to start web development using python My goal is to learn the web
development in python from the basic level and understand the big web
development projects like Django , MoinMoin Wiki , Plone  and network
programming further with twisted.

I have found Web2Py to be an easy library to quickly use and develop the
web application. Is there any other library to start my development with.
and
does my plan of learning Web2Py is good for Web development and getting
involved in the big projects like Django , MoinMoin Wiki , Plone.

*Regards
*
*Chitrank Dixit
*
*IIPS-DAVV
*
*Indore (M.P.) , India *
*MCA
*
*trackleech.blogspot.in*
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From modulok at gmail.com  Fri May 31 15:43:28 2013
From: modulok at gmail.com (Modulok)
Date: Fri, 31 May 2013 13:43:28 -0600
Subject: How to Begin Web Development with Python ?
In-Reply-To: <CAH7uNX2kUEcLd4zF1g=Wk35Are_vG-BtD4fgvCey4TM8JuPHog@mail.gmail.com>
References: <CAH7uNX2kUEcLd4zF1g=Wk35Are_vG-BtD4fgvCey4TM8JuPHog@mail.gmail.com>
Message-ID: <CAN2+Epa7P4hiRWtYQ0xye8mo4kZLGVmBG_7Q2kxa2VhpFBxLUg@mail.gmail.com>

> I have learnt python and used it for various purposes for scietific
> computing using sage and GUI development using Tkinter and lots more. I
> want to start web development using python My goal is to learn the web
> development in python from the basic level and understand the big web
> development projects like Django , MoinMoin Wiki , Plone  and network
> programming further with twisted.
>
> I have found Web2Py to be an easy library to quickly use and develop the
> web application. Is there any other library to start my development with.
> and
> does my plan of learning Web2Py is good for Web development and getting
> involved in the big projects like Django , MoinMoin Wiki , Plone.
>
>
Each web framework is kind of its own niche. I wouldn't learn one for the
purpose of learning another. For example to use Django effectively requires
knowledge specific to Django. Aside from some casual similarities between
various web frameworks they're all pretty different. If you feel comfortable
with web2Py and it does what you need - use the heck out of it!

I've heard good things about Web2Py but not used it myself.

I used Django for a while but found it to usually be over complicated for
most
of my needs. In other areas it wasn't advanced enough. (For instance I had
an
unusual requirement once for composite foreign key support, something
Django's
ORM couldn't handle at the time. I also disliked the template language. By
the
time I replaced the ORM and the template language the only thing I was
really
using was the URL routing so I jumped ship. (Don't get me wrong, I know
people who love Django - just not me.)

Cherrypy is neat but I found it to be more spartan than I prefer. I've since
settled on Flask with SQLAlchemy and am liking it very much. It's a nice
middle
ground. It also has extensive documentation and example files too. Of
course it
really helped that I already knew SQLAlchemy, thus pairing it with Flask was
cake.

While not a web framework, learning SQLAlchemy is useful in its own right
because it can be used in a wide variety of projects and is used by some web
frameworks. It's also an excellent package that lets you use most of the
features of your specific database backend. For web apps staying abstract is
usually a good idea, but honestly how often do you change SQL backends? I
think
I've done it once in my career. I've found the advantage of using database
specific features generally outweighs the drawbacks. This is especially
true if
you have more than one client/website accessing the same database.
SQLAlchemy
gets me the best of both worlds. I can define check constraints and
enumerations
and all the other goodies and have them match between database clients.

If you don't already know this from scientific computing, learning some raw
SQL
is quite useful too! Sometimes you need a non-trivial query.

-Modulok-
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From b13das91 at gmail.com  Fri May 31 05:12:58 2013
From: b13das91 at gmail.com (BIBHU DAS)
Date: Fri, 31 May 2013 02:12:58 -0700 (PDT)
Subject: Create a file in /etc/ as a non-root user
Message-ID: <0e688580-c0fb-4caf-8fb1-f622b2c7bcb5@googlegroups.com>

I am a python novice;request all to kindly bear with me.

fd = open('/etc/file','w')
fd.write('jpdas')
fd.close()


The above snippet fails with:

Jagannath-MacBook-Pro:~ jpdas$ python testUmask.py
Traceback (most recent call last):
  File "testUmask.py", line 3, in <module>
    fd = open('/etc/file','w')
IOError: [Errno 13] Permission denied: '/etc/file'


Any Idea how to create a file in /etc as non-root user?Can i use umask or chmod.......confused


From luca.cerone at gmail.com  Fri May 31 05:27:18 2013
From: luca.cerone at gmail.com (Luca Cerone)
Date: Fri, 31 May 2013 02:27:18 -0700 (PDT)
Subject: Create a file in /etc/ as a non-root user
In-Reply-To: <0e688580-c0fb-4caf-8fb1-f622b2c7bcb5@googlegroups.com>
References: <0e688580-c0fb-4caf-8fb1-f622b2c7bcb5@googlegroups.com>
Message-ID: <4fc3af47-2dc4-4de1-9479-53741215c3a2@googlegroups.com>

> fd = open('/etc/file','w')
> 
> fd.write('jpdas')
> 
> fd.close()
> 
> 
Hi Bibhu, that is not a Python problem, but a permission one.
You should configure the permissions so that you have write access to the folder.
However unless you know what you are doing it is discouraged to save your
file in the /etc/ folder.

I don't know if on Mac the commands are the same, but in Unix systems (that I guess Mac is) you can manage permissions with chmod.


From davea at davea.name  Fri May 31 07:11:58 2013
From: davea at davea.name (Dave Angel)
Date: Fri, 31 May 2013 07:11:58 -0400
Subject: Create a file in /etc/ as a non-root user
In-Reply-To: <4fc3af47-2dc4-4de1-9479-53741215c3a2@googlegroups.com>
References: <0e688580-c0fb-4caf-8fb1-f622b2c7bcb5@googlegroups.com>
	<4fc3af47-2dc4-4de1-9479-53741215c3a2@googlegroups.com>
Message-ID: <51A8857E.90907@davea.name>

On 05/31/2013 05:27 AM, Luca Cerone wrote:
>> fd = open('/etc/file','w')
>>
>> fd.write('jpdas')
>>
>> fd.close()
>>
>>
> Hi Bibhu, that is not a Python problem, but a permission one.
> You should configure the permissions so that you have write access to the folder.
> However unless you know what you are doing it is discouraged to save your
> file in the /etc/ folder.
>
> I don't know if on Mac the commands are the same, but in Unix systems (that I guess Mac is) you can manage permissions with chmod.
>

That directory is protected from users for a reason.  You defeat that 
and risk the system.

Bibhu:  for that reason I'd suggest simply telling your users to run 
your script as root.  If they trust you, and it breaks something, at 
least they know why they were doing it.

    sudo  python  riskyscript.py




-- 
DaveA


From alister.ware at ntlworld.com  Fri May 31 10:02:36 2013
From: alister.ware at ntlworld.com (Alister)
Date: Fri, 31 May 2013 14:02:36 GMT
Subject: Create a file in /etc/ as a non-root user
References: <0e688580-c0fb-4caf-8fb1-f622b2c7bcb5@googlegroups.com>
	<4fc3af47-2dc4-4de1-9479-53741215c3a2@googlegroups.com>
	<mailman.2487.1369998737.3114.python-list@python.org>
Message-ID: <042qt.10122$tu1.2940@fx20.am4>

On Fri, 31 May 2013 07:11:58 -0400, Dave Angel wrote:

> On 05/31/2013 05:27 AM, Luca Cerone wrote:
>>> fd = open('/etc/file','w')
>>>
>>> fd.write('jpdas')
>>>
>>> fd.close()
>>>
>>>
>> Hi Bibhu, that is not a Python problem, but a permission one.
>> You should configure the permissions so that you have write access to
>> the folder.
>> However unless you know what you are doing it is discouraged to save
>> your file in the /etc/ folder.
>>
>> I don't know if on Mac the commands are the same, but in Unix systems
>> (that I guess Mac is) you can manage permissions with chmod.
>>
>>
> That directory is protected from users for a reason.  You defeat that
> and risk the system.
> 
> Bibhu:  for that reason I'd suggest simply telling your users to run
> your script as root.  If they trust you, and it breaks something, at
> least they know why they were doing it.
> 
>     sudo  python  riskyscript.py

Bibhu without wishing to seem rude, the fact that you had to ask this 
question indicates that you almost certainly should not be writing to 
this directory.

/etc is used to store configuration files for the operating system & if 
you inadvertently corrupt the wrong one then you could kill the system.

if you can provide more details regarding what you are actually trying to 
achieve you may get some better answers & will almost certainly save 
yourself a whole heap of pain


-- 
It is not for me to attempt to fathom the inscrutable workings of 
Providence.
		-- The Earl of Birkenhead


From rosuav at gmail.com  Fri May 31 10:42:13 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 1 Jun 2013 00:42:13 +1000
Subject: Create a file in /etc/ as a non-root user
In-Reply-To: <042qt.10122$tu1.2940@fx20.am4>
References: <0e688580-c0fb-4caf-8fb1-f622b2c7bcb5@googlegroups.com>
	<4fc3af47-2dc4-4de1-9479-53741215c3a2@googlegroups.com>
	<mailman.2487.1369998737.3114.python-list@python.org>
	<042qt.10122$tu1.2940@fx20.am4>
Message-ID: <CAPTjJmpmrdS2ApGkRZ7s_U+pzXnkhohCE4zx6nidMZ08x0jvsQ@mail.gmail.com>

On Sat, Jun 1, 2013 at 12:02 AM, Alister <alister.ware at ntlworld.com> wrote:
> /etc is used to store configuration files for the operating system & if
> you inadvertently corrupt the wrong one then you could kill the system.

Expanding on this:

http://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard

The FHS applies to Linux, but you'll find it close to what other
Unix-like OSes use too.

It's extremely common to *read* config files from directories like
/etc, but to require root privileges to edit them. If you need to
store data files for some application that runs as your own user, one
good place is a dot-file or directory in your home directory - for
instance, I have:

/home/rosuav/.wine/
/home/rosuav/.bash_history
/home/rosuav/.ssh/
/home/rosuav/.SciTE.session

and many more. All of these are happily read/written by processes
running under the user 'rosuav' (my primary login user). If a
different user fires up bash, a different .bash_history will be used.
This system works well for users that represent humans.

The other type of user is the one that, well, doesn't represent a
human :) Figuring out where they can store files is a bit harder.
PostgreSQL gets itself a directory somewhere - maybe /opt/postgresql,
maybe /var/lib/postgresql - and restricts itself to that. But the
directory is created by root and then handed over (chowned) to the
other user.

Both these options work well; random processes editing stuff in /etc doesn't :)

ChrisA


From nobody at nowhere.com  Fri May 31 20:20:17 2013
From: nobody at nowhere.com (Nobody)
Date: Sat, 01 Jun 2013 01:20:17 +0100
Subject: Create a file in /etc/ as a non-root user
References: <0e688580-c0fb-4caf-8fb1-f622b2c7bcb5@googlegroups.com>
Message-ID: <pan.2013.06.01.00.20.14.288000@nowhere.com>

On Fri, 31 May 2013 02:12:58 -0700, BIBHU DAS wrote:

> I am a python novice;request all to kindly bear with me.
> 
> fd = open('/etc/file','w')
> fd.write('jpdas')
> fd.close()
> 
> 
> The above snippet fails with:

> IOError: [Errno 13] Permission denied: '/etc/file'

As it should.

> Any Idea how to create a file in /etc as non-root user?

This should not be possible. The language used is irrelevant.



From python.list at tim.thechases.com  Fri May 31 20:49:19 2013
From: python.list at tim.thechases.com (Tim Chase)
Date: Fri, 31 May 2013 19:49:19 -0500
Subject: Create a file in /etc/ as a non-root user
In-Reply-To: <pan.2013.06.01.00.20.14.288000@nowhere.com>
References: <0e688580-c0fb-4caf-8fb1-f622b2c7bcb5@googlegroups.com>
	<pan.2013.06.01.00.20.14.288000@nowhere.com>
Message-ID: <20130531194919.6b5e6b07@bigbox.christie.dr>

On 2013-06-01 01:20, Nobody wrote:
> On Fri, 31 May 2013 02:12:58 -0700, BIBHU DAS wrote:
> > Any Idea how to create a file in /etc as non-root user?
> 
> This should not be possible. The language used is irrelevant.

It's theoretically possible to pre-create the file (or a
subdirectory) in /etc as root, then "chown" it to have a group for
which certain users can be members.  Something like

  $ su -   # or "sudo sh"
  # addgroup bibhusers
  # mkdir /etc/bibhu
  # chown :bibhusers /etc/bibhu
  # chmod g+rwx /etc/bibhu
  # for user in bibhu tim guido; do adduser $user bibhusers ; done
  # exit
  $ logout

Upon next login, the users listed in the "for user in ..." command
should have write access to the directory created in /etc

Not that this would generally be considered a good idea, but if you
wanted to have a global configuration and wanted select users (as
members of a defined group) to have the ability to tweak this global
configuration, this is how it would be done.  Otherwise, it's
generally advisable to just have one admin maintain the global
configuration file and then give users a local (in
$HOME/.config/$APPNAME/filename.ext) configuration file to override
those global settings.

-tkc





From lourensjan.ugen at gmail.com  Fri May 31 05:41:35 2013
From: lourensjan.ugen at gmail.com (Lourens-Jan Ugen)
Date: Fri, 31 May 2013 02:41:35 -0700 (PDT)
Subject: Finding Relative Maxima in Python3
Message-ID: <6acf9ce5-eed1-4115-aa93-71d2e182db79@googlegroups.com>

Hi all,

The last few days I've been working on a script to manipulate some scientific data. One thing I would like to be able to do is find relative maxima in a data set. 
I'm using numpy in python3 (which I think I can't do without because of utf16 encoding of my data source) and a series of np.arrays. When looking around the web and some forums I came across the scipy function argrelextrema, which seemed to do just what I wanted. The problem is that I can't get the function to work, probably because scipy in python3 does not yet support the argrelextrema function. I can however, not find a reference to this really being the problem, and was wondering if someone here could maybe help me out.
The code I used is shown below. The function to return the maximum values is called by a different script. Then, when running, it returns an error like the one below the code. 

Script:
import numpy as np
import scipy as sp

def max_in_array_range(MaxArray, Column, LowBound):
	'''
	Finding the max value an array with a predefined in a certain column and from a threshold index.
	The complete array is loaded through Max Array. The column is first selected. 
	The, the LowBound is called (the data is only interesting from a certain point onward.
	'''
	TempArray = MaxArray[:, Column]	# Creation of Temporary Array to ensure 1D Array and specification of the LowBound in the next line.
	return sp.argrelextrema(TempArray[LowBound:], np.greater)


Error message:
Traceback (most recent call last):
  File "MyScript.py", line 15, in <module>
    Varrr = FD.max_in_array_range(CalcAndDiffArray, 5 ,MyBound)
  File "/MyPath/Script.py", line 82, in max_in_array_range
    return sp.argrelmax(TempArray[LowBound:], np.greater)
AttributeError: 'module' object has no attribute 'argrelmax'


From clp2 at rebertia.com  Fri May 31 05:54:38 2013
From: clp2 at rebertia.com (Chris Rebert)
Date: Fri, 31 May 2013 02:54:38 -0700
Subject: Finding Relative Maxima in Python3
In-Reply-To: <6acf9ce5-eed1-4115-aa93-71d2e182db79@googlegroups.com>
References: <6acf9ce5-eed1-4115-aa93-71d2e182db79@googlegroups.com>
Message-ID: <CAMZYqRSTmuKABDLLKsS2MjttAr+yJZi0d3xAv6oGM1qRzi41Pg@mail.gmail.com>

On May 31, 2013 2:46 AM, "Lourens-Jan Ugen" <lourensjan.ugen at gmail.com>
wrote:
>
> Hi all,
>
> The last few days I've been working on a script to manipulate some
scientific data. One thing I would like to be able to do is find relative
maxima in a data set.
> I'm using numpy in python3 (which I think I can't do without because of
utf16 encoding of my data source) and a series of np.arrays. When looking
around the web and some forums I came across the scipy function
argrelextrema, which seemed to do just what I wanted. The problem is that I
can't get the function to work, probably because scipy in python3 does not
yet support the argrelextrema function. I can however, not find a reference
to this really being the problem, and was wondering if someone here could
maybe help me out.
> The code I used is shown below. The function to return the maximum values
is called by a different script. Then, when running, it returns an error
like the one below the code.
>
> Script:
> import numpy as np
> import scipy as sp
<snip>
> Error message:
> Traceback (most recent call last):
>   File "MyScript.py", line 15, in <module>
>     Varrr = FD.max_in_array_range(CalcAndDiffArray, 5 ,MyBound)
>   File "/MyPath/Script.py", line 82, in max_in_array_range
>     return sp.argrelmax(TempArray[LowBound:], np.greater)
> AttributeError: 'module' object has no attribute 'argrelmax'

The docs would seem to indicate that that function resides in the "signal"
submodule of scipy:
http://docs.scipy.org/doc/scipy-dev/reference/generated/scipy.signal.argrelmax.html#scipy.signal.argrelmax

Hence, it would be sp.signal.argrelmax() as opposed to just sp.argrelmax()

Cheers,
Chris
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From nikos.gr33k at gmail.com  Fri May 31 11:20:54 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 08:20:54 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and install
	the latest?
Message-ID: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>

I'am using CentOS v6.4 on my VPS and hence 'yum' install manager and i just tried:

Code:
root at nikos [~]# which python
/usr/bin/python
root at nikos [~]# which python3
/root/.local/lib/python2.7/bin/python3
root at nikos [~]# which python3.3
/root/.local/lib/python2.7/bin/python3.3
root at nikos [~]#

Why so many pythons in my system.
Now in the case of my Python3 installation, it looks like i have two parallel installations of Python3, but i don't. One is almost certainly a symlink to the other and not an actual installation.

I'm thinking of:

yum remove python
yum remove python3
yum remove python3.3

and 

yum install python3.3.2 from scratch.

I'm sceptic about uninstalling python 2.x though. Seems to me as a bad idea because most of the core system utilities are written in Python 2.6+. Yum, for example, is a collection of Python 2.6 programs. If i actually do "yum remove python" i will see most of my core system get listed in the uninstall dependency list -- which is a Bad Thing.

But then again i dont like the idea of having too many Python into my system.
What is you opinion?


From fabiosantosart at gmail.com  Fri May 31 11:37:06 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Fri, 31 May 2013 16:37:06 +0100
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
Message-ID: <CAA=1kxRwhcHqowXXt0rpoPTSh0jbw3vFeEL212WFUxPkRZxfkA@mail.gmail.com>

On 31 May 2013 16:28, "???????? ??????" <nikos.gr33k at gmail.com> wrote:
>
> I'am using CentOS v6.4 on my VPS and hence 'yum' install manager and i
just tried:
>
> Code:
> root at nikos [~]# which python
> /usr/bin/python
> root at nikos [~]# which python3
> /root/.local/lib/python2.7/bin/python3
> root at nikos [~]# which python3.3
> /root/.local/lib/python2.7/bin/python3.3
> root at nikos [~]#
>
> Why so many pythons in my system.
> Now in the case of my Python3 installation, it looks like i have two
parallel installations of Python3, but i don't. One is almost certainly a
symlink to the other and not an actual installation.
>
> I'm thinking of:
>
> yum remove python
> yum remove python3
> yum remove python3.3
>
> and
>
> yum install python3.3.2 from scratch.
>
> I'm sceptic about uninstalling python 2.x though. Seems to me as a bad
idea because most of the core system utilities are written in Python 2.6+.
Yum, for example, is a collection of Python 2.6 programs. If i actually do
"yum remove python" i will see most of my core system get listed in the
uninstall dependency list -- which is a Bad Thing.
>
> But then again i dont like the idea of having too many Python into my
system.
> What is you opinion?
> --
> http://mail.python.org/mailman/listinfo/python-list

Check if python3 and python3.3 aren't the same. Run them and look at the
"intro" lines.
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From nikos.gr33k at gmail.com  Fri May 31 11:41:52 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 08:41:52 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <mailman.2492.1370014635.3114.python-list@python.org>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2492.1370014635.3114.python-list@python.org>
Message-ID: <d6549478-c1bd-4ffd-926c-3770fffa1de7@googlegroups.com>

?? ?????????, 31 ????? 2013 6:37:06 ?.?. UTC+3, ? ??????? F?bio Santos ??????:

> Check if python3 and python3.3 aren't the same. Run them and look at the "intro" > lines.

root at nikos [~]# python -V
Python 2.6.6
root at nikos [~]# python3 -V
Python 3.3.0
root at nikos [~]# python3.3 -V
Python 3.3.0
root at nikos [~]# python3
Python 3.3.0 (default, Apr  6 2013, 01:53:31) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-3)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
root at nikos [~]# python3.3
Python 3.3.0 (default, Apr  6 2013, 01:53:31) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-3)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
root at nikos [~]# 


From ian.g.kelly at gmail.com  Fri May 31 11:59:30 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 31 May 2013 09:59:30 -0600
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <d6549478-c1bd-4ffd-926c-3770fffa1de7@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2492.1370014635.3114.python-list@python.org>
	<d6549478-c1bd-4ffd-926c-3770fffa1de7@googlegroups.com>
Message-ID: <CALwzid==gSUa5EDUPBwPwNMxO89yETqjZZbVBmq+ypKTtFGG-g@mail.gmail.com>

On Fri, May 31, 2013 at 9:41 AM, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> ?? ?????????, 31 ????? 2013 6:37:06 ?.?. UTC+3, ? ??????? F?bio Santos ??????:
>
>> Check if python3 and python3.3 aren't the same. Run them and look at the "intro" > lines.
>
> root at nikos [~]# python -V
> Python 2.6.6
> root at nikos [~]# python3 -V
> Python 3.3.0
> root at nikos [~]# python3.3 -V
> Python 3.3.0

So it looks like you have two Python installations, one for Python 2
and one for Python 3.  Why is that too many?


From torriem at gmail.com  Fri May 31 11:55:03 2013
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 31 May 2013 09:55:03 -0600
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
Message-ID: <51A8C7D7.704@gmail.com>

On 05/31/2013 09:20 AM, ???????? ?????? wrote:
> Why so many pythons in my system. Now in the case of my Python3
> installation, it looks like i have two parallel installations of
> Python3, but i don't. One is almost certainly a symlink to the other
> and not an actual installation.

Well is it a symlink?

> I'm thinking of:
> 
> yum remove python
> yum remove python3
> yum remove python3.3

What a fantastic way to completely break your os!  Python 2 is is a deep
dependency of CentOS.  You cannot remove it.  Python3 and 3.3 can be
removed of course.


From nikos.gr33k at gmail.com  Fri May 31 13:10:05 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 10:10:05 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <mailman.2495.1370015715.3114.python-list@python.org>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
Message-ID: <db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>

?? ?????????, 31 ????? 2013 6:55:03 ?.?. UTC+3, ? ??????? Michael Torrie ??????:
> On 05/31/2013 09:20 AM, ???????? ?????? wrote:
> 
> > Why so many pythons in my system. Now in the case of my Python3
> 
> > installation, it looks like i have two parallel installations of
> 
> > Python3, but i don't. One is almost certainly a symlink to the other
> 
> > and not an actual installation.
> 
> 
> 
> Well is it a symlink?
> 
> 
> 
> > I'm thinking of:
> 
> > 
> 
> > yum remove python
> 
> > yum remove python3
> 
> > yum remove python3.3
> 
> 
> 
> What a fantastic way to completely break your os!  Python 2 is is a deep
> 
> dependency of CentOS.  You cannot remove it.  Python3 and 3.3 can be
> 
> removed of course.

root at nikos [~]# ls -al /usr/bin/python*
-rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python*
lrwxrwxrwx 1 root root    6 Apr  5 20:34 /usr/bin/python2 -> python*
-rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python2.6*
-rwxr-xr-x 1 root root 1418 Feb 22 02:00 /usr/bin/python2.6-config*
lrwxrwxrwx 1 root root   24 Apr  7 22:10 /usr/bin/python3 -> /opt/python3/bin/python3*
lrwxrwxrwx 1 root root   16 Apr  5 20:35 /usr/bin/python-config -> python2.6-config*
root at nikos [~]# 

so, i should just 'yum remove python3' ?

> root at nikos [~]# python3 -V 
> Python 3.3.0 
> root at nikos [~]# python3.3 -V 
> Python 3.3.0 

whre is that 3.3 anyway that which presents?


From nikos.gr33k at gmail.com  Fri May 31 13:11:06 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 10:11:06 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
Message-ID: <d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>

root at nikos [~]# yum remove python3
Loaded plugins: fastestmirror
Setting up Remove Process
No Match for argument: python3
Loading mirror speeds from cached hostfile
 * base: ftp.plusline.de
 * extras: ftp.plusline.de
 * updates: ftp.plusline.de
base                                                                                                                          | 3.7 kB     00:00     
extras                                                                                                                        | 3.5 kB     00:00     
updates                                                                                                                       | 3.4 kB     00:00     
updates/primary_db                                                                                                            | 2.6 MB     00:00     
vz-base                                                                                                                       |  951 B     00:00     
vz-updates                                                                                                                    |  951 B     00:00     
No Packages marked for removal
root at nikos [~]# yum remove python3.3
Loaded plugins: fastestmirror
Setting up Remove Process
No Match for argument: python3.3
Loading mirror speeds from cached hostfile
 * base: ftp.plusline.de
 * extras: ftp.plusline.de
 * updates: ftp.plusline.de
No Packages marked for removal
root at nikos [~]# 


i don'y understand, why didnt it removed it neither of ways?


From nikos.gr33k at gmail.com  Fri May 31 13:16:44 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 10:16:44 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
Message-ID: <98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>

root at nikos [~]# which python
/usr/bin/python
root at nikos [~]# which python2
/usr/bin/python2
root at nikos [~]# which python3
/root/.local/lib/python2.7/bin/python3
root at nikos [~]# which python3.3
/root/.local/lib/python2.7/bin/python3.3
root at nikos [~]# 

So i have
2.6
2.7
3
3.3 

4 installations?


From ian.g.kelly at gmail.com  Fri May 31 13:33:20 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 31 May 2013 11:33:20 -0600
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
Message-ID: <CALwzidk_yYENp5+hAj7MS2dY8-Z73H9cfwtjM93eLuJA-h9Rqw@mail.gmail.com>

On Fri, May 31, 2013 at 11:16 AM, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> root at nikos [~]# which python
> /usr/bin/python
> root at nikos [~]# which python2
> /usr/bin/python2
> root at nikos [~]# which python3
> /root/.local/lib/python2.7/bin/python3
> root at nikos [~]# which python3.3
> /root/.local/lib/python2.7/bin/python3.3
> root at nikos [~]#
>
> So i have
> 2.6
> 2.7
> 3
> 3.3
>
> 4 installations?

Oh, I see.  The python3 and python3.3 are probably the same binary, though.

In any case, since Python 2.7 and Python 3 are both installed under
/root/.local, it looks like you didn't install them using yum in the
first place.  You probably installed them from source.  If that's the
case, you can probably just rm -rf the python2.7 folder from each of
the /root/.local subfolders that has it.


From nikos.gr33k at gmail.com  Fri May 31 13:42:05 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 10:42:05 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <mailman.2499.1370021651.3114.python-list@python.org>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
Message-ID: <f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>

OMG i gave by mistake 

root at nikos [/]# rm -rf /root/.local/

did i screwed up my remote VPS which i host 10 peoples webpages?


From ian.g.kelly at gmail.com  Fri May 31 13:55:51 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 31 May 2013 11:55:51 -0600
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
Message-ID: <CALwzidn8X6g8CMHOCvzqOH7vmOv2hBbO1rEMOPdP9Qx0jK60tQ@mail.gmail.com>

On Fri, May 31, 2013 at 11:42 AM, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> OMG i gave by mistake
>
> root at nikos [/]# rm -rf /root/.local/
>
> did i screwed up my remote VPS which i host 10 peoples webpages?

I don't know, is that where you were keeping the data?

The website still appears to be working, as best I can tell from this
computer.  I've never actually been able to view it from here, because
I get a UnicodeDecodeError at this line:

host = socket.gethostbyaddr( os.environ['REMOTE_ADDR'] )[0]

But at least I'm still seeing that error, so the server is still
responding to requests.


From nikos.gr33k at gmail.com  Fri May 31 14:02:50 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 11:02:50 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <mailman.2500.1370022994.3114.python-list@python.org>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
Message-ID: <c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>

?? ?????????, 31 ????? 2013 8:55:51 ?.?. UTC+3, ? ??????? Ian ??????:
> On Fri, May 31, 2013 at 11:42 AM, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> 
> > OMG i gave by mistake
> 
> >
> 
> > root at nikos [/]# rm -rf /root/.local/
> 
> >
> 
> > did i screwed up my remote VPS which i host 10 peoples webpages?
> 
> 
> 
> I don't know, is that where you were keeping the data?
> 
> 
> 
> The website still appears to be working, as best I can tell from this
> 
> computer.  I've never actually been able to view it from here, because
> 
> I get a UnicodeDecodeError at this line:
> 
> 
> 
> host = socket.gethostbyaddr( os.environ['REMOTE_ADDR'] )[0]
> 
> 
> 
> But at least I'm still seeing that error, so the server is still
> 
> responding to requests.

Everything seem to be workign as expected, my webiste and the other 10 client websites just chhecked.

luckily i keep my stuff at /homw/nikos so there are untouched.
i hope i havent deleted anything though system need form /root/.local but i guess this is where root's user personal stuff and instalation of python from source where. i ddidnt know if it has soemhtign else.

root at nikos [/]# which python
/usr/bin/python
root at nikos [/]# which python3
/root/.local/lib/python2.7/bin/python3
root at nikos [/]# which python3.3
/usr/local/bin/python3.3
root at nikos [/]# ls -l /usr/bin/py
pydoc             pygettext.py      python            python2.6         python3           
pyflakes          pynche            python2           python2.6-config  python-config     
root at nikos [/]# ls -l /usr/bin/python*
-rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python*
lrwxrwxrwx 1 root root    6 Apr  5 20:34 /usr/bin/python2 -> python*
-rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python2.6*
-rwxr-xr-x 1 root root 1418 Feb 22 02:00 /usr/bin/python2.6-config*
lrwxrwxrwx 1 root root   24 Apr  7 22:10 /usr/bin/python3 -> /opt/python3/bin/python3*
lrwxrwxrwx 1 root root   16 Apr  5 20:35 /usr/bin/python-config -> python2.6-config*
root at nikos [/]# 

please tell me how to unistall python 2.6 and just keep 2.7
and install 3.3.2 please uisng yum.

yum install python3 doesnt work for me.


From fabiosantosart at gmail.com  Fri May 31 18:03:28 2013
From: fabiosantosart at gmail.com (=?ISO-8859-1?Q?F=E1bio_Santos?=)
Date: Fri, 31 May 2013 23:03:28 +0100
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
Message-ID: <CAA=1kxQZMysRZ10SxfAzJiBTLopjt8UBkgpzxOqJS=qdpFOotA@mail.gmail.com>

On 31 May 2013 19:09, "???????? ??????" <nikos.gr33k at gmail.com> wrote:
> > On Fri, May 31, 2013 at 11:42 AM, ???????? ?????? <nikos.gr33k at gmail.com>
wrote:
> >
> > > OMG i gave by mistake
> > > root at nikos [/]# rm -rf /root/.local/
> > > did i screwed up my remote VPS which i host 10 peoples webpages?

Couldn't you check ten websites which are your responsibility, instead of
asking this list?

> Everything seem to be workign as expected, my webiste and the other 10
client websites just chhecked.

Good.

> please tell me how to unistall python 2.6 and just keep 2.7
> and install 3.3.2 please uisng yum.
>
> yum install python3 doesnt work for me.

No. Wait. Why are you uninstalling python 2.6? Because you have too many
python installations?

If you're on a production server with client data, should you really have a
root shell?
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From bouncingcats at gmail.com  Fri May 31 18:50:00 2013
From: bouncingcats at gmail.com (David)
Date: Sat, 1 Jun 2013 08:50:00 +1000
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
Message-ID: <CAMPXz=odoB+cY4aoAMME3vJefwwENM5tzr0ZZOMMTms92zJAHw@mail.gmail.com>

On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
>
> Why so many pythons in my system.

Explained below, underneath each pertinent info you provided.

First, let's discuss Python 2.6:

On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> I'am using CentOS v6.4 on my VPS and hence 'yum' install manager and i just
> tried:
>
> Code:
> root at nikos [~]# which python
> /usr/bin/python

This is the version of that CentOS 6 is using. It is Python 2.6 as
shown in the next paragraph. This version is essential to CentOS 6.
This cannot be changed or upgraded without so much work that no sane
person on the planet would bother. Stop worrying about it.

On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
>
> root at nikos [~]# python -V
> Python 2.6.6

See above.

On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
>
> root at nikos [/]# ls -l /usr/bin/python*
> -rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python*
> lrwxrwxrwx 1 root root    6 Apr  5 20:34 /usr/bin/python2 -> python*
> -rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python2.6*
> -rwxr-xr-x 1 root root 1418 Feb 22 02:00 /usr/bin/python2.6-config*
[... python3 line removed for clarity ...]
> lrwxrwxrwx 1 root root   16 Apr  5 20:35 /usr/bin/python-config ->
> python2.6-config*

Apart from the bizarre trailing '*' characters which for which I have
no sane explanation, all of the above is standard for Python 2.6 which
is essential for Centos 6. Stop worrying about it.

Now let's talk about yum:

On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> root at nikos [~]# yum remove python3
[...]
> No Match for argument: python3
[...]
> root at nikos [~]# yum remove python3.3
[...]
> No Match for argument: python3.3
>
> i don'y understand, why didnt it removed it neither of ways?

Your yum setup does not find python3 or python3.3 packages.
So you could not have used yum to install it.
Therefore, you cannot use yum to remove it.
And, you cannot use yum to install it.

Now let's talk about Python 2.7:

On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> root at nikos [~]# which python3
> /root/.local/lib/python2.7/bin/python3

There's a python2.7 directory there under /root/.local. Maybe you
installed python2.7 from source using some kind of 'make install'
command (ie not using yum)? If so, and you wish to remove it, there
will probably be another 'make' command to remove it, which must be
run from the same directory that you ran 'make install'. Try 'make
help' in that directory. Maybe someone else can explain why there is a
python3 command under that directory, because I can't.

Now let's talk about Python 3:

On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
>
> root at nikos [~]# ls -al /usr/bin/python*
[...]
> lrwxrwxrwx 1 root root   24 Apr  7 22:10 /usr/bin/python3 ->
> /opt/python3/bin/python3*

There's a python3 directory there under /opt. Maybe you installed
python3 from source using some kind of 'make install' command (ie not
using yum)? If so, and you wish to remove it, there will probably be
another 'make' command to remove it, which must be run from the same
directory that you ran 'make install'. Try 'make help' in that
directory.

On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
>
> OMG i gave by mistake
>
> root at nikos [/]# rm -rf /root/.local/
>
> did i screwed up my remote VPS which i host 10 peoples webpages?

When trying something you don't fully understand, first experiment
somewhere you don't care if bad things happen.

On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> Should i remove them all and install the latest?

No. Different versions do different things. Don't install or remove
them until you understand the different things they do.


From rosuav at gmail.com  Fri May 31 19:38:02 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 1 Jun 2013 09:38:02 +1000
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <CAMPXz=odoB+cY4aoAMME3vJefwwENM5tzr0ZZOMMTms92zJAHw@mail.gmail.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
	<CAMPXz=odoB+cY4aoAMME3vJefwwENM5tzr0ZZOMMTms92zJAHw@mail.gmail.com>
Message-ID: <CAPTjJmoaxoPV6Kb9iDRg4TYufnxqjSuy18wiLWKQGM1Mgsk16w@mail.gmail.com>

On Sat, Jun 1, 2013 at 8:50 AM, David <bouncingcats at gmail.com> wrote:
> On 01/06/2013, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
>>
>> root at nikos [/]# ls -l /usr/bin/python*
>> -rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python*
>> lrwxrwxrwx 1 root root    6 Apr  5 20:34 /usr/bin/python2 -> python*
>> -rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python2.6*
>> -rwxr-xr-x 1 root root 1418 Feb 22 02:00 /usr/bin/python2.6-config*
> [... python3 line removed for clarity ...]
>> lrwxrwxrwx 1 root root   16 Apr  5 20:35 /usr/bin/python-config ->
>> python2.6-config*
>
> Apart from the bizarre trailing '*' characters which for which I have
> no sane explanation...

I believe that indicates that his 'ls' is aliased to 'ls --classify',
which puts * after executables (and / after directories, and @ after
symlinks, also a few others). Not a problem.

ChrisA


From bouncingcats at gmail.com  Fri May 31 20:18:05 2013
From: bouncingcats at gmail.com (David)
Date: Sat, 1 Jun 2013 10:18:05 +1000
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <CAPTjJmoaxoPV6Kb9iDRg4TYufnxqjSuy18wiLWKQGM1Mgsk16w@mail.gmail.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
	<CAMPXz=odoB+cY4aoAMME3vJefwwENM5tzr0ZZOMMTms92zJAHw@mail.gmail.com>
	<CAPTjJmoaxoPV6Kb9iDRg4TYufnxqjSuy18wiLWKQGM1Mgsk16w@mail.gmail.com>
Message-ID: <CAMPXz=qqnGZeoLOffSMOme93Z7jbvJ5LquiTLG8ghUi+h9BmLw@mail.gmail.com>

On 01/06/2013, Chris Angelico <rosuav at gmail.com> wrote:
> On Sat, Jun 1, 2013 at 8:50 AM, David <bouncingcats at gmail.com> wrote:
>>
>> Apart from the bizarre trailing '*' characters which for which I have
>> no sane explanation...
>
> I believe that indicates that his 'ls' is aliased to 'ls --classify',
> which puts * after executables (and / after directories, and @ after
> symlinks, also a few others). Not a problem.

Ah, old skool. I have seen that before now that you mention it. Thanks
for the correction.
I knew I didn't have all the answers, but felt that I'd try some pig
wrestling anyway.


From rosuav at gmail.com  Fri May 31 20:24:22 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 1 Jun 2013 10:24:22 +1000
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <CAMPXz=qqnGZeoLOffSMOme93Z7jbvJ5LquiTLG8ghUi+h9BmLw@mail.gmail.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
	<CAMPXz=odoB+cY4aoAMME3vJefwwENM5tzr0ZZOMMTms92zJAHw@mail.gmail.com>
	<CAPTjJmoaxoPV6Kb9iDRg4TYufnxqjSuy18wiLWKQGM1Mgsk16w@mail.gmail.com>
	<CAMPXz=qqnGZeoLOffSMOme93Z7jbvJ5LquiTLG8ghUi+h9BmLw@mail.gmail.com>
Message-ID: <CAPTjJmo3omXAz5h7M+iCvw7q-xr3fTZ56ACZp+u=V7zeYW_u-Q@mail.gmail.com>

On Sat, Jun 1, 2013 at 10:18 AM, David <bouncingcats at gmail.com> wrote:
> On 01/06/2013, Chris Angelico <rosuav at gmail.com> wrote:
>> On Sat, Jun 1, 2013 at 8:50 AM, David <bouncingcats at gmail.com> wrote:
>>>
>>> Apart from the bizarre trailing '*' characters which for which I have
>>> no sane explanation...
>>
>> I believe that indicates that his 'ls' is aliased to 'ls --classify',
>> which puts * after executables (and / after directories, and @ after
>> symlinks, also a few others). Not a problem.
>
> Ah, old skool. I have seen that before now that you mention it. Thanks
> for the correction.
> I knew I didn't have all the answers, but felt that I'd try some pig
> wrestling anyway.

Yeah. I know that particular one because I have l aliased to ls -CF
(aka --columns --classify), mainly because it came that way as a
commented-out entry in my first Debian. Have since become quite
accustomed to it; to me, 'l' means 'look' (I do love my MUDs), so I'm
considering aliasing 'gl' to 'pwd' so that I can 'glance' too :)

Hmm. What other MUD commands have obvious Unix equivalents?

say --> echo
emote --> python -c
attack --> sudo rm -f

ChrisA


From breamoreboy at yahoo.co.uk  Fri May 31 20:43:30 2013
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 01 Jun 2013 01:43:30 +0100
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <CAMPXz=qqnGZeoLOffSMOme93Z7jbvJ5LquiTLG8ghUi+h9BmLw@mail.gmail.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
	<CAMPXz=odoB+cY4aoAMME3vJefwwENM5tzr0ZZOMMTms92zJAHw@mail.gmail.com>
	<CAPTjJmoaxoPV6Kb9iDRg4TYufnxqjSuy18wiLWKQGM1Mgsk16w@mail.gmail.com>
	<CAMPXz=qqnGZeoLOffSMOme93Z7jbvJ5LquiTLG8ghUi+h9BmLw@mail.gmail.com>
Message-ID: <kobg2v$jc9$1@ger.gmane.org>

On 01/06/2013 01:18, David wrote:
> I knew I didn't have all the answers, but felt that I'd try some pig
> wrestling anyway.
>

To carry on with the animal analogy, the OP appears to me a very 
dangerous combination of headless chicken and bull in a china shop.

-- 
"Steve is going for the pink ball - and for those of you who are 
watching in black and white, the pink is next to the green." Snooker 
commentator 'Whispering' Ted Lowe.

Mark Lawrence



From nikos.gr33k at gmail.com  Fri May 31 19:30:48 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 16:30:48 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <mailman.2505.1370040610.3114.python-list@python.org>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
	<mailman.2505.1370040610.3114.python-list@python.org>
Message-ID: <5dcbe51b-407d-4285-bec8-f3fda7e77742@googlegroups.com>

Indeed i have comiled python 2.7 and 3.3 form source after wget and
./configure an make install

but i belive somehting is  mixed up althouh python works ok.

root at nikos [/opt/python3/bin]# ls -al
total 15180
drwxr-xr-x 2 root root    4096 Apr  7 22:09 ./
drwxr-xr-x 6 root root    4096 Apr  7 22:09 ../
lrwxrwxrwx 1 root root       8 Apr  7 22:09 2to3 -> 2to3-3.3*
-rwxr-xr-x 1 root root     103 Apr  7 22:09 2to3-3.3*
lrwxrwxrwx 1 root root       7 Apr  7 22:09 idle3 -> idle3.3*
-rwxr-xr-x 1 root root     101 Apr  7 22:09 idle3.3*
lrwxrwxrwx 1 root root       8 Apr  7 22:09 pydoc3 -> pydoc3.3*
-rwxr-xr-x 1 root root      86 Apr  7 22:09 pydoc3.3*
lrwxrwxrwx 1 root root       9 Apr  7 22:09 python3 -> python3.3*
-rwxr-xr-x 2 root root 7757695 Apr  7 22:09 python3.3*
lrwxrwxrwx 1 root root      17 Apr  7 22:09 python3.3-config ->
python3.3m-config*
-rwxr-xr-x 2 root root 7757695 Apr  7 22:09 python3.3m*
-rwxr-xr-x 1 root root    1980 Apr  7 22:09 python3.3m-config*
lrwxrwxrwx 1 root root      16 Apr  7 22:09 python3-config ->
python3.3-config*
lrwxrwxrwx 1 root root      10 Apr  7 22:09 pyvenv -> pyvenv-3.3*
-rwxr-xr-x 1 root root     238 Apr  7 22:09 pyvenv-3.3*
root at nikos [/opt/python3/bin]# make help
make: *** No rule to make target `help'.  Stop.
root at nikos [/opt/python3/bin]#


cant remove it.

Why you say i cant just yum install python3.3.2

that way it would be installed correcttly automaticall by yum manager
and if later i want to remove ot to install 3.3.3 or a later version i
would have to do yum remove python3.3.2

but yum cant seem to find any python packages to install.

Still i feel my system is a bit messed p and i just want to leave the
2.6 installed and remove all the rest python and then yum install
the_latest_one.


From rosuav at gmail.com  Fri May 31 19:39:27 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 1 Jun 2013 09:39:27 +1000
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <5dcbe51b-407d-4285-bec8-f3fda7e77742@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
	<mailman.2505.1370040610.3114.python-list@python.org>
	<5dcbe51b-407d-4285-bec8-f3fda7e77742@googlegroups.com>
Message-ID: <CAPTjJmoNHpNqpuukPwk5P4JvLURdSOJT9Y+PYhgjOAbr22M01w@mail.gmail.com>

On Sat, Jun 1, 2013 at 9:30 AM, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> Still i feel my system is a bit messed p and i just want to leave the
> 2.6 installed and remove all the rest python and then yum install
> the_latest_one.

It's not half as messed up as... uhh, scratch that. It's not half as
messed up as the testbox I have at work. (Yeah, we'll go with that.
More courteous.) You do not have a problem there that is worth
breaking your system for.

ChrisA


From ian.g.kelly at gmail.com  Fri May 31 19:55:38 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 31 May 2013 17:55:38 -0600
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <5dcbe51b-407d-4285-bec8-f3fda7e77742@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
	<mailman.2505.1370040610.3114.python-list@python.org>
	<5dcbe51b-407d-4285-bec8-f3fda7e77742@googlegroups.com>
Message-ID: <CALwzid=snXAWEsF+ZHNYeJzOtCs9vmXEBBq0hD0Dh8mEetWbQw@mail.gmail.com>

On Fri, May 31, 2013 at 5:30 PM, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> Indeed i have comiled python 2.7 and 3.3 form source after wget and
> ./configure an make install
>
> but i belive somehting is  mixed up althouh python works ok.
>
> root at nikos [/opt/python3/bin]# ls -al
> ...
> root at nikos [/opt/python3/bin]# make help
> make: *** No rule to make target `help'.  Stop.
> root at nikos [/opt/python3/bin]#
>
>
> cant remove it.

The Makefile would be located in the source directory where you built
Python, not in the installation directory.  But in any case, I don't
think the Python Makefile includes an uninstall option.  If you want
to uninstall Python that was built from source, you need to remove the
files by hand.

> Why you say i cant just yum install python3.3.2

Because CentOS 6 evidently does not provide a package for any version
of Python other than 2.6.  If you want to install another version, you
will need to do it from source.


From nikos.gr33k at gmail.com  Fri May 31 20:08:38 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 17:08:38 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <mailman.2509.1370044587.3114.python-list@python.org>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
	<mailman.2505.1370040610.3114.python-list@python.org>
	<5dcbe51b-407d-4285-bec8-f3fda7e77742@googlegroups.com>
	<mailman.2509.1370044587.3114.python-list@python.org>
Message-ID: <6a741732-76cc-4a4d-9eee-69991f9e4e96@googlegroups.com>

?? ???????, 1 ??????? 2013 2:55:38 ?.?. UTC+3, ? ??????? Ian ??????:
> On Fri, May 31, 2013 at 5:30 PM, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> 
> > Indeed i have comiled python 2.7 and 3.3 form source after wget and
> 
> > ./configure an make install
> 
> >
> 
> > but i belive somehting is  mixed up althouh python works ok.
> 
> >
> 
> > root at nikos [/opt/python3/bin]# ls -al
> 
> > ...
> 
> > root at nikos [/opt/python3/bin]# make help
> 
> > make: *** No rule to make target `help'.  Stop.
> 
> > root at nikos [/opt/python3/bin]#
> 
> >
> 
> >
> 
> > cant remove it.
> 
> 
> 
> The Makefile would be located in the source directory where you built
> 
> Python, not in the installation directory.  But in any case, I don't
> 
> think the Python Makefile includes an uninstall option.  If you want
> 
> to uninstall Python that was built from source, you need to remove the
> 
> files by hand.
> 
> 
> 
> > Why you say i cant just yum install python3.3.2
> 
> 
> 
> Because CentOS 6 evidently does not provide a package for any version
> 
> of Python other than 2.6.  If you want to install another version, you
> 
> will need to do it from source.


Do you think that i should have my VPS copmany to install ubuntu for me and use apt-get install python3 ?

I think ubuntu is friendlier.


From rosuav at gmail.com  Fri May 31 20:19:15 2013
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 1 Jun 2013 10:19:15 +1000
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <6a741732-76cc-4a4d-9eee-69991f9e4e96@googlegroups.com>
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<d083368d-c679-48ce-9969-bf976efccac8@googlegroups.com>
	<98f99db1-d200-4291-a050-cbbb30290d4c@googlegroups.com>
	<mailman.2499.1370021651.3114.python-list@python.org>
	<f6163943-106e-4411-8bc5-8760d8388936@googlegroups.com>
	<mailman.2500.1370022994.3114.python-list@python.org>
	<c5d25712-7b61-44b3-94ef-956fe758df18@googlegroups.com>
	<mailman.2505.1370040610.3114.python-list@python.org>
	<5dcbe51b-407d-4285-bec8-f3fda7e77742@googlegroups.com>
	<mailman.2509.1370044587.3114.python-list@python.org>
	<6a741732-76cc-4a4d-9eee-69991f9e4e96@googlegroups.com>
Message-ID: <CAPTjJmo+A5WhdHZb47kxNuvhurRoL5vkRScniq1L-Kf2rq0+bQ@mail.gmail.com>

On Sat, Jun 1, 2013 at 10:08 AM, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> ?? ???????, 1 ??????? 2013 2:55:38 ?.?. UTC+3, ? ??????? Ian ??????:
> > [ snip lots of double-spaced quoted text ]
>
> Do you think that i should have my VPS copmany to install ubuntu for me and use apt-get install python3 ?
>
> I think ubuntu is friendlier.

Probably friendlier than humans will be, considering that Ubuntu
doesn't complain about careless use of Google Groups.

Why not try making your own administrative decisions, rather than
expecting other people to validate you? Are you that short on
confidence that you need someone to say "Yes yes, you're doing the
right thing" and pat you on the back?

ChrisA


From torriem at gmail.com  Fri May 31 20:59:39 2013
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 31 May 2013 18:59:39 -0600
Subject: Too many python installations. Should i remove them all and
	install the latest?
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On 05/31/2013 12:02 PM, ???????? ?????? wrote:
> please tell me how to unistall python 2.6 and just keep 2.7
> and install 3.3.2 please uisng yum.

Python 2.6 is required for CentOS to function.  You simply cannot remove
it.  You can't replace it with 2.7 either.  You can install 2.7
alongside it if you want (seems like you have).


From ian.g.kelly at gmail.com  Fri May 31 13:24:26 2013
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 31 May 2013 11:24:26 -0600
Subject: Too many python installations. Should i remove them all and
	install the latest?
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References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
	<mailman.2495.1370015715.3114.python-list@python.org>
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On Fri, May 31, 2013 at 11:10 AM, ???????? ?????? <nikos.gr33k at gmail.com> wrote:
> root at nikos [~]# ls -al /usr/bin/python*
> -rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python*
> lrwxrwxrwx 1 root root    6 Apr  5 20:34 /usr/bin/python2 -> python*
> -rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python2.6*
> -rwxr-xr-x 1 root root 1418 Feb 22 02:00 /usr/bin/python2.6-config*
> lrwxrwxrwx 1 root root   24 Apr  7 22:10 /usr/bin/python3 -> /opt/python3/bin/python3*
> lrwxrwxrwx 1 root root   16 Apr  5 20:35 /usr/bin/python-config -> python2.6-config*
> root at nikos [~]#
>
> so, i should just 'yum remove python3' ?

If you're not using it, and if yum isn't going to remove anything else
that has it as a dependency, then go ahead.

On the other hand, there's really not much harm in leaving it.  Python
2.6 is already your default Python.

Is this the same system where you recently spent a lot of time
upgrading your web scripts to Python 3?


From nikos.gr33k at gmail.com  Fri May 31 13:38:15 2013
From: nikos.gr33k at gmail.com (=?ISO-8859-7?B?zenq/Ovh7/Igyu/98eHy?=)
Date: Fri, 31 May 2013 10:38:15 -0700 (PDT)
Subject: Too many python installations. Should i remove them all and
	install the latest?
In-Reply-To: <mailman.2498.1370021465.3114.python-list@python.org>
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	<db0b9074-3f86-4de6-97bf-d0443d800b92@googlegroups.com>
	<mailman.2498.1370021465.3114.python-list@python.org>
Message-ID: <0e75b06d-9e3c-4ecd-b5e5-e616a1e904cb@googlegroups.com>

?? ?????????, 31 ????? 2013 8:24:26 ?.?. UTC+3, ? ??????? Ian ??????:

> On the other hand, there's really not much harm in leaving it.  Python 
> 2.6 is already your default Python.

> Is this the same system where you recently spent a lot of time
> upgrading your web scripts to Python 3?

Yes, its the same system but it reports python 4 times.
I just hate seeing this:

root at nikos [~]# which python 
/usr/bin/python 
root at nikos [~]# which python2 
/usr/bin/python2 
root at nikos [~]# which python3 
/root/.local/lib/python2.7/bin/python3 
root at nikos [~]# which python3.3 
/root/.local/lib/python2.7/bin/python3.3 
root at nikos [~]# 

and this too:

> root at nikos [~]# ls -al /usr/bin/python* 
> -rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python* 
> lrwxrwxrwx 1 root root    6 Apr  5 20:34 /usr/bin/python2 -> python* 
> -rwxr-xr-x 3 root root 4864 Feb 22 02:00 /usr/bin/python2.6* 
> -rwxr-xr-x 1 root root 1418 Feb 22 02:00 /usr/bin/python2.6-config* 
> lrwxrwxrwx 1 root root   24 Apr  7 22:10 /usr/bin/python3 -> /opt/python3/bin/python3* 
> lrwxrwxrwx 1 root root   16 Apr  5 20:35 /usr/bin/python-config -> python2.6-config* 
> root at nikos [~]# 

How can i fix this please.

i just want to leave 2.7 and downlaod 3.3.2
could you please tell me what commands i should issue?


From alister.ware at ntlworld.com  Fri May 31 13:24:19 2013
From: alister.ware at ntlworld.com (Alister)
Date: Fri, 31 May 2013 17:24:19 GMT
Subject: Too many python installations. Should i remove them all and
	install the latest?
References: <063fc449-5582-4a84-9eea-35e04344dbe0@googlegroups.com>
Message-ID: <715qt.11476$Wt5.8275@fx24.am4>

On Fri, 31 May 2013 08:20:54 -0700, ???????? ?????? wrote:

> I'am using CentOS v6.4 on my VPS and hence 'yum' install manager and i
> just tried:
> 
> Code:
> root at nikos [~]# which python /usr/bin/python root at nikos [~]# which
> python3 /root/.local/lib/python2.7/bin/python3 root at nikos [~]# which
> python3.3 /root/.local/lib/python2.7/bin/python3.3 root at nikos [~]#
> 
> Why so many pythons in my system.
> Now in the case of my Python3 installation, it looks like i have two
> parallel installations of Python3, but i don't. One is almost certainly
> a symlink to the other and not an actual installation.
> 
> I'm thinking of:
> 
> yum remove python yum remove python3 yum remove python3.3
> 
> and
> 
> yum install python3.3.2 from scratch.
> 
> I'm sceptic about uninstalling python 2.x though. Seems to me as a bad
> idea because most of the core system utilities are written in Python
> 2.6+. Yum, for example, is a collection of Python 2.6 programs. If i
> actually do "yum remove python" i will see most of my core system get
> listed in the uninstall dependency list -- which is a Bad Thing.
> 
> But then again i dont like the idea of having too many Python into my
> system.
> What is you opinion?

Do not "Yum Remove Python" as you suggest this will remove vital system 
tools.

I have both Python 2.7 & python3 (Python 3.3) on my Fedora system with no 
problems so i would not worry 



-- 
No question is so difficult as one to which the answer is obvious.


From sjo.india at gmail.com  Fri May 31 23:30:08 2013
From: sjo.india at gmail.com (Sudheer Joseph)
Date: Fri, 31 May 2013 20:30:08 -0700 (PDT)
Subject: netcdF4 variables
Message-ID: <de9d0c8d-d7cc-45a8-a53e-06efed145700@googlegroups.com>

Dear members,
                    I have been using python NetcdF for some time. I understand that we can get variables from a netcdf one by one by using
temp=ncf.variable['temp'][:]
but is there  a way to get a list of variables with out the rest of the stuff as seen below?
some hing like a list
xx=nc,variables[:]
should get me all variable names with out other surrounding stuff??
with best regards.
Sudheer

In [4]: ncf.variables
Out[4]: OrderedDict([(u'LON', <netCDF4.Variable object at 0x254aad0>), (u'LAT', <netCDF4.Variable object at 0x254ab50>), (u'DEPTH1_1', <netCDF4.Variable object at 0x254abd0>), (u'TAX', <netCDF4.Variable object at 0x254ac50>), (u'DIF_FD1', <netCDF4.Variable object at 0x254acd0>), (u'DIF_FD2', <netCDF4.Variable object at 0x254ad50>), (u'DIF_FD3', <netCDF4.Variable object at 0x254add0>), (u'DIF_FD4', <netCDF4.Variable object at 0x254ae50>), (u'DIF_FD5', <netCDF4.Variable object at 0x254aed0>), (u'DEPTH', <netCDF4.Variable object at 0x254af50>), (u'DEPTH_bnds', <netCDF4.Variable object at 0x261b050>), (u'TIME', <netCDF4.Variable object at 0x261b0d0>), (u'TEMP_BIAS', <netCDF4.Variable object at 0x261b150>)])