Test Page

. Well, at least 
validator.w3c.org and www.cast.org/bobby spot out lots of HTML4 errors 
so I still can believe Opera is correct here :-)

markus
-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From donn at drizzle.com  Thu Sep  6 23:17:39 2001
From: donn at drizzle.com (Donn Cave)
Date: Fri, 07 Sep 2001 03:17:39 -0000
Subject: how to run python script from Unix Shell?
References: 
Message-ID: <999832657.64669@yabetcha.drizzle.com>

Quoth davidnet800 at yahoo.com (David):

 3) PATH=$PWD:$PATH

Bash is looking for a file that's (1) executable.  The file needs
the interpreter line (2) to be successfully executed.  Bash will
look for it only in certain places (3).  (You can use "." or ""
in PATH to run commands in the local directory.  I wouldn't do
that, but if you must, put it at the very end of PATH.)

	Donn Cave, donn at drizzle.com

From cgale1 at _remove_home.com  Wed Sep 12 19:34:52 2001
From: cgale1 at _remove_home.com (Van Gale)
Date: Wed, 12 Sep 2001 23:34:52 GMT
Subject: What is Python good for?
References: <6f8cb8c9.0109120541.132432d4@posting.google.com> <9nnsck02uat@enews1.newsguy.com> 
Message-ID: 

"John Beppu"  wrote in message
news:mailman.1000330590.19641.python-list at python.org...
> [  date  ] 2001/09/12 | Wednesday | 04:44 PM
> [ author ] Alex Martelli 
>
> > If you think Perl is easy to master, then you're a very unusual
> > sort of person.
>
> Not necessarily unusual -- just different from you.
>
> My background in /bin/sh and C programming made perl
> really easy, because it just felt like perl fit
> right in the middle.  I can't say perl was very hard
> for me to learn

When I first learned perl (sometime after 1.0, but before 2.0), I was having
to do a lot of system glue work with sh/csh/awk/sed.  Perl was a god-send
for me, and quite easy to learn.  Since then I had to work on an extremely
large project that was using perl 5.  I had a difficult time adjusting to
that environment in spite of having mastered perl 2, and maintenence of code
written by others on the project was a complete nightmare.

I'd define mastered as: 1) not having to reference the man page or a book
for anything during coding, 2) being able to read and understand code that
is intentionally obfuscated by the author, 3) know what language constructs
to avoid and how to use others properly (e.g. knowing how to construct a
regular expression with no, or at least minimal, backtracking).

I'd agree with Alex that Perl 5 is not easy to master using that definition.
Points 1 and 2 make Python easy to master.  Point 3 is a little harder in
Python, but even if you use a construct improperly (e.g. inefficiently)
someone else won't have any problem reading your code and understanding what
you were trying to do.  (Hmm, I suppose that isn't true for a program with
bad OO design... I find tracing object hierarchies tedious)

From chrishbarker at home.net  Mon Sep 24 14:52:50 2001
From: chrishbarker at home.net (Chris Barker)
Date: Mon, 24 Sep 2001 11:52:50 -0700
Subject: Idea about method parameters
References: <2728946.ogB4TqSGss@lunix.schabi.de>
Message-ID: <3BAF8102.70E435C8@home.net>

Markus Schaber wrote:

> Now I'd love to have the possibility to shorten this by typing:
> 
> class A:
>     def m(self, self.value):
>         pass # or the other work to be done

I suspect that this will clash with the internals somewhere, but I love
it!

-Chris

-- 
Christopher Barker,
Ph.D.                                                           
ChrisHBarker at home.net                 ---           ---           ---
http://members.home.net/barkerlohmann ---@@       -----@@       -----@@
                                   ------@@@     ------@@@     ------@@@
Oil Spill Modeling                ------   @    ------   @   ------   @
Water Resources Engineering       -------      ---------     --------    
Coastal and Fluvial Hydrodynamics --------------------------------------
------------------------------------------------------------------------

From gerhard.nospam at bigfoot.de  Mon Sep 24 13:19:21 2001
From: gerhard.nospam at bigfoot.de (Gerhard =?iso-8859-1?Q?H=E4ring?=)
Date: Mon, 24 Sep 2001 19:19:21 +0200
Subject: Linux and Numeric extensions...
References: 
Message-ID: 

On Sun, 23 Sep 2001 16:31:51 GMT, Carl Johan Rehn wrote:
>Dear friends, 
>
>I am running Linux Suse 7.2 and have recently installed the Numeric 
>extensions to Python, but when I import the Numeric library the Python 
>interpreter cannot find the library.

Lets see. Do you have installed it as per the instructions in the README:

$ python setup_all.py install

as user root?

>I suppose I have to add
>the path to the site-packages/Numeric library somewhere, but I don't know 
>where.

No, that's not necessary.

I have set my umask to a non-default value, so usually have to do a

$ chmod -R go+rX /usr/lib/python2.1

after installing modules. Make that /usr/lib/python2.0 if you have the original
Python 2.0 from SuSE 7.2.

Gerhard
-- 
mail:   gerhard  bigfoot  de       registered Linux user #64239
web:    http://www.cs.fhm.edu/~ifw00065/    OpenPGP public key id 86AB43C0
public key fingerprint: DEC1 1D02 5743 1159 CD20  A4B6 7B22 6575 86AB 43C0
reduce(lambda x,y:x+y,map(lambda x:chr(ord(x)^42),tuple('zS^BED\nX_FOY\x0b')))

From skip at pobox.com  Wed Sep  5 15:21:27 2001
From: skip at pobox.com (Skip Montanaro)
Date: Wed, 5 Sep 2001 14:21:27 -0500
Subject: Performance of list comprehensions vs. map
In-Reply-To: <3B966B1C.120D0AF6@home.net>
References: <3B966B1C.120D0AF6@home.net>
Message-ID: <15254.31543.427137.830680@localhost.localdomain>

    Chris> I just took another look at:

    Chris> http://musi-cal.mojam.com/~skip/python/fastpython.html

    Chris> specifically, the loops section:

    fp.html> List comprehensions were added to Python in version 2.0 as
    fp.html> well. They provide a syntactically more compact way of writing
    fp.html> the above for loop:

    fp.html> newlist = [s.upper() for s in list]

    fp.html> It's not really any faster than the for loop version, however.

    Chris> my question is: Why not? 

map() is a single function that doesn't return control to the interpreter
until it's work is done.  List comprehensions are essentially just syntactic
sugar for the equivalent for loop.  Both the for loop and list comprehension
are implemented as loops using multiple virtual machine instructions.
Perhaps the easiest way to see this is to write three equivalent functions
and disassemble them:

    def map_str(n):
        return map(str, range(n))

    def lc_str(n):
        return [str(i) for i in range(n)]

    def for_str(n):
        l = []
        append = l.append
        for i in range(n):
            append(str(i))

    assert map_str(5) == lc_str(5) == for_str(5)

    import dis
    print "disassembling map_str"
    dis.dis(map_str)
    print "disassembling lc_str"
    dis.dis(lc_str)
    print "disassembling for_str"
    dis.dis(for_str)

    Chris> I like list comprehensions a lot, and they would seem to offer a
    Chris> way to get optimization over a for loop, much like map does, but
    Chris> apparently not. If map can do the loop in C, why can't a list
    Chris> comprehension?

In theory, an optimizer could identify and replace some list comprehensions
with calls to map, but they wouldn't be quite equivalent.  In the examples
above, there is no guarantee that the definition of the str function doesn't
change during the execution of either the for loop or the list comprehension
(think multiple threads of execution ;-).  The call to map, on the other
hand, binds str once before map is called.

    Chris> I think a big stumbling block is that Python has no concept of
    Chris> the "homogenous" sequence. There are modules that provide such a
    Chris> thing (Numeric, array), and indeed, the string type is a
    Chris> homogenous sequence, but Python itself does not understand this
    Chris> concept, so that if a map or list comprehesion is using a
    Chris> homogenous list, it still has to check the type of every element
    Chris> as it goes through the list. For example:

    Chris> [2*a for a in list]

    Chris> If the interpreter could just check once what the type of all the
    Chris> elements of list were, it would only have to figure out what 2*a
    Chris> meant once, and it could whip through the list very
    Chris> quickly. Indeed, if you do:

    Chris> [2*a for a in a_string]

But there is no guarantee that the list you are operating on isn't modified
by another thread during execution.

I've been thinking of this a little in the context of Ken Simpson's recently
announced PyInline module.  The biggest reason I can't use it right now
(ignoring it's pre-alpha version number ;-) in my own code is precisely that
I operate on dicts, lists and tuples a lot.  I'm sure that's true for other
Python programmers.  The problem of easily writing C code that can operate
on lists (for example) boils down to deciding how you will map Python's
lists to something that is efficiently representable in C.  Perl's inline
module does this with something called typemaps.  (Look in something like
/usr/local/lib/perl5/5.6.1/ExtUtils for a file called "typemap".)  I don't
really understand everything that's going on in that file, but it does
provide mappings.  For instance, a "char **" argument followed by an
"unsigned int" arg might map to and from a list of strings and a length, an
"int *" followed by "unsigned int" might map to and from a list of ints,
etc.  I'm not sure quite how you'd do dicts (or if you could in a reasonable
fashion without listifying them somehow).

I suspect this is about as close as Python will ever come to understanding
homogeneous containers at the language level.

    Chris> I've proposed similar ideas in the past, and not gotten much
    Chris> response. I imagine my ideas are full of holes, but no one has
    Chris> taken the time to point them out to me yet. I have come to the
    Chris> conclusion that the really sharp minds on this list (and the
    Chris> folks that might be qualified to actually impliment such a thing)
    Chris> are not really interested in something like this that is a
    Chris> perfomance only improvement. Am I right? or is the idea just so
    Chris> stupid that it's not worth commenting on?

It's not a matter of lack of interest as much as a desire to keep the
semantics of Python and lack of time.  Here are some efforts I'm aware of.
Note that there are lots of ways performance can be addressed, not just by
constraining types.

    * Rattlesnake (my thing) - a new register-oriented virtual machine whose
      premise is that the current stack-oriented virtual machine does far
      too much data shuffling

    * Psyco (Armin Rego) - a run-time specializing virtual machine that sees
      what sorts of types are input to a function and compiles a type- or
      value-specific version of that function on-the-fly.  I believe Armin
      is looking at some JIT code generators in addition to or instead of
      another virtual machine.

    * Static typing SIG (http://www.python.org/sigs/types-sig/) - I'm not
      familiar with this SIGs work, so you'll have to browse the archives.

    * Python2C (Bill Tutt, Greg Stein) - A "module compiler" that generates
      a C version of a Python module.  http://www.mudlib.org/~rassilon/p2c/

    * PEP 266 - A "pie in the sky" PEP I wrote that proposes that global
      data could be accessed like local data if you reverse the roles of who
      keeps references up-to-date.

    * Various peephole optimizers - I wrote one a few years ago.  There's
      also Michael Hudson's bytecodehacks project (on Sourceforge).  The
      xfreeze bytecode freezer (part of the standard distribution?) also
      does some peepholing.

I'm sure there are several I'm missing.

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/

From boyd at insultant.net  Fri Sep 21 21:52:17 2001
From: boyd at insultant.net (Boyd Roberts)
Date: Sat, 22 Sep 2001 03:52:17 +0200
Subject: How to configure and install Python
References:  
Message-ID: <9ogr21$jc4$1@neon.noos.net>

"Oleg Broytmann"  a ?crit dans le message news: mailman.1001081723.23491.python-list at python.org...
>    Yes, but you do not have C compiler. Install gcc.

or your PATH is wrong doesn't include a C compiler.

install gcc?  the beginning of the end ...

From kseehof at neuralintegrator.com  Thu Sep 13 07:26:36 2001
From: kseehof at neuralintegrator.com (Ken Seehof)
Date: Thu, 13 Sep 2001 04:26:36 -0700
Subject: Fw: What is Python good for?
Message-ID: <018201c13c46$f416d980$4d14b43f@kens>

> On Wed, 12 Sep 2001, Ken Seehof wrote:
>
> > Oh yes, the overall effect is definitely "ooh-ahh".  I was
> > just commenting that I haven't noticed any specific unique
> > python features that are "ooh-ahh".
>
> Here's something that came up recently that if it doesn't make you go
> "ooh-ahh", then it will make you go "whoa":
>
> ---
> >>> def a():
> ...   return 'abc'
> ...
> >>> def b():
> ...   return 123
> ...
> >>> a.func_code=b.func_code
> >>> a()
> 123
> Ignacio Vazquez-Abrams  

Whoa.  Check this out (python 2.1 or later required):

from __future__ import nested_scopes  # if this is python 2.1

def enhance_method(klass, method_name, replacement):
    'replace a class instance method'
    method = getattr(klass, method_name)
    setattr(klass, method_name, new.instancemethod(
        lambda *args, **kwds: replacement(method, *args, **kwds),
        None, klass))

This replaces a method in an existing class with a function that takes the
original method as an argument.  The replacement function is of the form:

def replacement(old_method, self, *args, **kwds):
   ...
   r = old_method(self, *args, **kwds)
   ...
   return r

Enjoy,
- Ken

From fredrik at pythonware.com  Sat Sep 29 12:05:55 2001
From: fredrik at pythonware.com (Fredrik Lundh)
Date: Sat, 29 Sep 2001 16:05:55 GMT
Subject: scanf style parsing
References: <3BB16A50.BAE082FE@cygnus-software.com>  <3BB2C7DA.F63EEAA7@cygnus-software.com>  <9p4a4f$kdd$1@inputplus.demon.co.uk>
Message-ID: 

Ralph Corderoy wrote:
> > or, much more preferably:
> >
> >     if filename[-4:] == '.txt':
>
> Overall, the Perl code's better.  It didn't have to hard-code the
> length of the string.

if it matters, use endswith instead:

    if filename.endswith('.txt'):
        ...

From stevesusenet at yahoo.com  Wed Sep 12 09:41:21 2001
From: stevesusenet at yahoo.com (Steve)
Date: 12 Sep 2001 06:41:21 -0700
Subject: What is Python good for?
Message-ID: <6f8cb8c9.0109120541.132432d4@posting.google.com>

I heard about Python briefly a few years ago when I just got out of
school and started programming professionally.

Now that I have a good command of some other languages and I see that
there is a windows port of Python I am thinking about learning it.

Why should I?

By that, I mean most languages try to do it all, but they usually end
up having unique strengths in some areas that draw users to it.

Java is great for server side programming.  Perl is easy, and has a
lot of built in features for text processing.  Visual Basic makes
generating windows client app interfaces very fast.

What is Python's major strength?  What benefit will someone have by
taking the time to learn it?

Where does Python fall short?

Thank in advance.

From tim at vegeta.ath.cx  Thu Sep 27 06:19:40 2001
From: tim at vegeta.ath.cx (Tim Hammerquist)
Date: Thu, 27 Sep 2001 10:19:40 GMT
Subject: Does there exist a Python-to-Perl translator ?
References: <3BB2D226.3C260A2C@Spam.Please>
Message-ID: 

Me parece que Weet Vanniks  dijo:
> This would help me produce Perl code after developing it in Python.
> 
> Thanks to all for answering.
> 
> Weet

Whatever for?  If you have to produce Perl code, why don't you write it?
Otherwise, what have the thousands of Perl programmers spent months
learning it for?

(Besides, if no one had to learn Perl, O'Reilly and Associates would
lose 60% of their sales...) 

OTOH, Perl 6's internals (codename: Parrot, ironically) may be your
answer.  In theory (and not anywhere near done), Perl and Python would
both compile to a common bytecode, executable by the same VM.  With that
in place, some have speculated on the ability to compile Python code to
Parrot bytecode, then spewing out equivalent Perl code.  See Eric
Raymond's article here:

    http://mail.python.org/pipermail/python-dev/2001-July/016406.html

This may very well be what you're looking for, but don't count on it
producing optimized code, and especially not pretty code.  Besides, Perl
6 isn't even due out for another few years, and Perl 6 will have a
significantly different syntax than Perl 5.

You might just have to learn Perl after all. 

Please, no flames from over-zealous Pythonistas.  Whether I know Perl or
not, I still spend 70% of my time programming at the '>>>' prompt or
with '#!/usr/local/bin/python' at the top of the buffer.

'ly 'yrs

Tim
-- 
How do I type "for i in *.dvi do xdvi i done" in a GUI?
    -- discussion in comp.os.linux.misc

From alf at orion.logilab.fr  Thu Sep 13 02:53:49 2001
From: alf at orion.logilab.fr (Alexandre Fayolle)
Date: Thu, 13 Sep 2001 06:53:49 +0000 (UTC)
Subject: [Poll] Private variables
References: 
Message-ID: 

On Wed, 12 Sep 2001 16:13:42 -0400, Tim Peters  wrote:
>[Alexandre Fayolle]
>> It is possible in python to get private class members by using names
>> beginning with 2 underscores, and finished by at least 1 underscore.
>
>You don't need an underscore at the end.  A name in a class is private if

Wooops. I, of course, meant 'at most 1 underscore'. 

Alexandre Fayolle
-- 
LOGILAB, Paris (France).
http://www.logilab.com   http://www.logilab.fr  http://www.logilab.org
Narval, the first software agent available as free software (GPL).

From TerryByrne1963 at yahoo.com  Tue Sep  4 10:57:27 2001
From: TerryByrne1963 at yahoo.com (Terry Byrne)
Date: 4 Sep 2001 07:57:27 -0700
Subject: How to get the return status of a command runned by os.popen4
References: <3B93C945.EB6DF7A8@magic.fr>
Message-ID: <93d52e82.0109040657.68633c40@posting.google.com>

Alain,

I've had good luck on Windows NT 4 with the following  combination:

    cmdPipe = os.popen(aCmdLine)
    resultStream = cmdPipe.read()

At this point you can read resultStream for any stdout feedback
returned by aCmdLine. Is that what you need?

-Terry

Alain Barthe  wrote in message news:<3B93C945.EB6DF7A8 at magic.fr>...
> Hi,
> 
> I cannot get the return status of a command runned by os.popen4 or
> popen2.popen4. File closing does not return the status as os.popen does.
> 
> I can get it with an object popen2.popen4, but it's not Windows
> compliant.
> 
> Anybody has the solution ?
> 
> Thanks.

From loewis at informatik.hu-berlin.de  Wed Sep 26 11:28:27 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 26 Sep 2001 17:28:27 +0200
Subject: what encoding is this?  How can I tell?  How can I translate?
References:  <87zo7j4fk1.fsf@psyche.dnsalias.org>   <3bb0b75c$0$53006$6e365a64@newsreader02.highway.telekom.at>
Message-ID: 

"Werner Schiendl"  writes:

> > Regardless, most of the latin-based encodings use the full range of
> > 256 bytes, yet they all differ from latin-1 (unless they are identical
> > to latin-1). Therefore, all of them, without exception, have characters
> > that cannot be transformed to UTF-8.
> >
> 
> I guess this is just a typo, but of course you can transform _any_ known
> encoding to Unicode (without loss of information).

Indeed; that should be "to latin-1".

Thanks,
Martin

From ws-news at gmx.at  Fri Sep  7 04:59:58 2001
From: ws-news at gmx.at (Werner Schiendl)
Date: Fri, 7 Sep 2001 10:59:58 +0200
Subject: zope installation
References:  <9ca06fb.0109031830.72f5b863@posting.google.com> <3b949e9f$0$26756$6e365a64@newsreader02.highway.telekom.at> <9ca06fb.0109061345.559f87e2@posting.google.com>
Message-ID: <3b988d40$0$22352$6e365a64@newsreader02.highway.telekom.at>

Hi,

try to post your problem to the Zope mailing list, if you did not already do
so.
If you are new to Zope, you should consider joining this mailing list
anyway.

see http://www.zope.org/Resources/MailingLists

The generic 'Zope' mailing list should be your best bet, there are lots of
people on it running Zope on Linux.

Search the archives in advance - the search works very well.

hth
Werner

"Kahikatea"  wrote in message
news:9ca06fb.0109061345.559f87e2 at posting.google.com...
> Digging a little further (/var/log/zope) reveals that it is hiccuping
> on something to due with syslog. However, not knowing python I have no
> idea what to do next.....
>
> "Werner Schiendl"  wrote in message
news:<3b949e9f$0$26756$6e365a64 at newsreader02.highway.telekom.at>...
> > Hi,
> >
> > not a Linux expert, but you normally need to configure which port should
be
> > used for which protocol and purpose. Further, ports below 1024 are
> > priviledged under Linux.
> >
> > I think it is inetd, which needs be configured. Ask some expert in Linux
on
> > how to do it.
> >
> > hth
> > Werner
> >
> > "Kahikatea"  wrote in message
> > news:9ca06fb.0109031830.72f5b863 at posting.google.com...
> > > Unfortunately this is happening to me too. Help!
> > >
> > > LeoDeBeo  wrote in message
> >  news:...
> > > > using redhat 7.1, i downloaded and installed the zope and zserver
> > > > rpm-packages
> > > > i start zserver by typing: service zope start (sysV-initialization
> >  script)
> > > > it says that startup was ok but the server immediately dies
> > > > in the messages file (/var/log/messages), the following error pops
up
> > > >
> > > > zope: zserver.sh startup succeeded
> > > > z2[1381]: Startup exception: error: (91, 'Protocol wrong type for
> >  socket')
> > > >
> > > > anyone an idea
> > > > help much appreciated

From s713221 at student.gu.edu.au  Mon Sep 17 01:31:49 2001
From: s713221 at student.gu.edu.au (Joal Heagney)
Date: Mon, 17 Sep 2001 15:31:49 +1000
Subject: Problems when building PIL
References: <3BA4D7CE.71F8E72B@olen.to>
Message-ID: <3BA58AC5.BC027954@student.gu.edu.au>

Joonas Paalasmaa wrote:
> 
> I get the following error when trying to build PIL on Linux.
> Python version is 1.5.1 .

Everything up to here seems fine.

> rdx313 at myra:~/Imaging-1.1.2/libImaging$ make check
> ./coretest
> >>> processing lena.ppm...
> >>> elapsed time: 0
> >>> as far as we tested, everything seems to be ok...
> xv test.ppm
> make: xv: Command not found

This part is just the check, which uses  the non-GPL program xv, which
may not be available on your machine. Don't worry about it.

> rdx313 at myra:~/Imaging-1.1.2/libImaging$ cd ..
> rdx313 at myra:~/Imaging-1.1.2$ make -f Makefile.pre.in boot
> rm -f *.o *~
> rm -f *.a tags TAGS config.c Makefile.pre python sedscript
> rm -f *.so *.sl so_locations
> VERSION=`python -c "import sys; print sys.version[:3]"`; \
> installdir=`python -c "import sys; print sys.prefix"`; \
> exec_installdir=`python -c "import sys; print sys.exec_prefix"`; \
> make -f ./Makefile.pre.in VPATH=. srcdir=. \
>         VERSION=$VERSION \
>         installdir=$installdir \
>         exec_installdir=$exec_installdir \
>         Makefile
> make[1]: Entering directory `/home/rdx/web/rdx313/Imaging-1.1.2'
> make[1]: *** No rule to make target
> `/usr/lib/python1.5/config/Makefile', needed by `sedscript'.  Stop.
> make[1]: Leaving directory `/home/rdx/web/rdx313/Imaging-1.1.2'
> make: *** [boot] Error 2
> rdx313 at myra:~/Imaging-1.1.2$

Okay. I'm not entirely sure what's happening here. Did you enter the
make -f bit yourself? Is it something stated to do in the instructions? 
Oh hold on. Sorted it out. You need to install the python-devel rpm.
This contains the config/Makefile that python was built with, and which
is used to configure modules with. It also contains all the python
headers you'll need.
Happy pythoneering.
-- 
      Joal Heagney is: _____           _____
   /\ _     __   __ _    |     | _  ___  |
  /__\|\  ||   ||__ |\  || |___|/_\|___] |
 /    \ \_||__ ||___| \_|! |   |   \   \ !

From rwhite at netins.net  Sun Sep 16 11:48:53 2001
From: rwhite at netins.net (Ron White)
Date: Sun, 16 Sep 2001 10:48:53 -0500
Subject: Confused newbie
References: <9o07ri$9o3$1@ins20.netins.net>
Message-ID: <9o2iu0$aki$1@ins20.netins.net>

Last night I discovered that the 486 with 16 meg of ram was the problem.  I
installed Python on a machine with more ram and the program runs just fine.
Thank you for your help.
Ron

"Ron White"  wrote in message
news:9o07ri$9o3$1 at ins20.netins.net...
> I downloaded Python 2.1.1 (a little over 6 meg) and installed it in a
win95
> machine.
>
> I am going through Josh Cogliati's Non-Programmers Tutorial for Python and
> there are several questions I hope I can get answers to.
> First, is there a document which tells you how to indent the various
cammand
> lines?  I have a lot of trouble with that.
>
> Secondly, I have typed in a program for printing out a calendar, but when
I
> try to run it I get the error that this program has committed a fatal
error
> and will be shut down.
> I thought maybe I didn't have the calendar library, but it appears that I
do
> in lib.
> One thing I've wondered is if I should have installed Python on drive c
> instead of drive e - maybe the program can't find the lib directory?
> The program is:
>
> import calendar
> year = input("Type in the year number:")
> calendar.prcal(year)
>
> Any help will be greatly appreciated.
> Thanks in advance,
> Ron
>
>
> --
> Ron White
> Amateur Radio  WA0MWW
> "God answers all knee mail"
>
>

From sheila at spamcop.net  Sun Sep  2 12:45:36 2001
From: sheila at spamcop.net (Sheila King)
Date: Sun, 02 Sep 2001 16:45:36 GMT
Subject: Help with Unicode? in Tkinter?
References:  
Message-ID: <6fn4pts9rnfu4akjqh5lm0e97qjaadg0o4@4ax.com>

On Sun, 2 Sep 2001 15:03:20 +0400 (MSD), Oleg Broytmann 
wrote in comp.lang.python in article
:

:On Sat, 1 Sep 2001, Sheila King wrote:
:SK> >>> print unichr(231)
:SK> Traceback (most recent call last):
:SK>   File "", line 1, in ?
:SK>     print unichr(231)
:SK> UnicodeError: ASCII encoding error: ordinal not in range(128)
:
:   This error indicates that you didn't edit your site.py (or
:sitecustomize.py) and didn't chnge default "ascii" encoding to the encoding
:of your terminal/locale.

Are you sure? I tried changing my locale to France, and I still get the
same errors I was getting when my locale was not France:

Python 2.1.1 (#20, Jul 20 2001, 01:19:29) [MSC 32 bit (Intel)] on win32
Type "copyright", "credits" or "license" for more information.
IDLE 0.8 -- press F1 for help
>>> import locale
>>> loc = locale.setlocale(locale.LC_ALL)
>>> locale.setlocale(locale.LC_ALL, 'fr')
'French_France.1252'
>>> print u'\xe7'
Traceback (most recent call last):
  File "", line 1, in ?
    print u'\xe7'
UnicodeError: ASCII encoding error: ordinal not in range(128)
>>> print unichr(231)
Traceback (most recent call last):
  File "", line 1, in ?
    print unichr(231)
UnicodeError: ASCII encoding error: ordinal not in range(128)
>>> print chr(231)
?
>>> 

Although, note that printing the ordinal 231 as a chr instead of as a
unichr works just fine.

Here is an interesting snippet, that I executed immediately following
the above:

>>> import string
>>> string.letters
'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\x83\x8a\x8c\x8e\x9a\x9c\x9e\x9f\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff'
>>> print string.letters
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz??????????????????????????????????????????????????????????????????????
>>> locale.setlocale(locale.LC_ALL, loc)
'C'
>>> string.letters
'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'
>>> print string.letters
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
>>> 

I guess I have found a way to proceed, thanks to Ignacio's suggestion. I
wonder if this is the usual way?

--
Sheila King
http://www.thinkspot.net/sheila/
http://www.k12groups.org/

From fredrik at pythonware.com  Mon Sep 17 13:28:49 2001
From: fredrik at pythonware.com (Fredrik Lundh)
Date: Mon, 17 Sep 2001 17:28:49 GMT
Subject: No spam in books
References: 
Message-ID: 

Andrew Nguyen wrote:
> The O'Reilly books have no mention of spam.

have you read them all?  there were exactly 87 spam references
in the final draft of my standard library book, and I'm pretty sure
the copy editor didn't remove all of them...

From s713221 at student.gu.edu.au  Sun Sep  2 10:09:44 2001
From: s713221 at student.gu.edu.au (Joal Heagney)
Date: Mon, 03 Sep 2001 00:09:44 +1000
Subject: wxpython
References: <7592d940.0109020157.5e3212e7@posting.google.com>
Message-ID: <3B923DA8.B50D3288@student.gu.edu.au>

Jock Mackenzie wrote:
> 
> I have been learning python/wxpython & have written a small program in
> wxpython that asks for input from the user  [using the function
> wxGetNumberFromUser()] then applies a formula and produces a long integer as
> a result.  I want to display the resulting number from the calculation on
> the wxFrame or wxPanel or in a dialogbox. I cannot find a function for doing
> this. Most message boxes only want to return a string not a long integer as
> I want.
> How do you do this??
> thanks in advance
> regards Jock.

You could pass it a string containing the string representation of the
integer

First we create a long integer.
>>> a = 10000000000000000000000000000000000000L
>>> a
10000000000000000000000000000000000000L

Then there's the str function
>>> str(a)
'10000000000000000000000000000000000000'

Then there's string substitution
>>> "%s" % a
'10000000000000000000000000000000000000'

Which finally allows you to construct sentences with dynamically filled
values.
>>> "%s is a %s" % (a, type(a))
"10000000000000000000000000000000000000 is a "
-- 
      Joal Heagney is: _____           _____
   /\ _     __   __ _    |     | _  ___  |
  /__\|\  ||   ||__ |\  || |___|/_\|___] |
 /    \ \_||__ ||___| \_|! |   |   \   \ !

From kirschh at lionbioscience.com  Fri Sep 21 06:28:46 2001
From: kirschh at lionbioscience.com (Harald Kirsch)
Date: 21 Sep 2001 12:28:46 +0200
Subject: How to derive import dependency structure
Message-ID: 

Let B.py be imported by A.py which generates --- in a very time
consuming process --- some data structure A.dat.

         import         generate
   B.py --------> A.py ----------> A.data

Currently A.dat is only generated if A.py is newer, but this is not
enough since A.dat must also be generated, if B.py is changed.

A.py and B.py is user written code and B.py represents in fact a more
complicated import-structure.

I could of course do some 'grep import A.py', but I guess there are
more pythonic solutions to find the dependency structure?

TIA,
  Harald Kirsch

-- 
----------------+------------------------------------------------------
Harald Kirsch   | kirschh at lionbioscience.com | "How old is the epsilon?"
LION bioscience | +49 6221 4038 172          |        -- Paul Erd?s
       *** Please do not send me copies of your posts. ***

From db3l at fitlinxx.com  Fri Sep 21 17:39:22 2001
From: db3l at fitlinxx.com (David Bolen)
Date: 21 Sep 2001 17:39:22 -0400
Subject: python version
References: 
Message-ID: 

"Steven D. Majewski"  writes:

> Of course, if you want to do it from the command line, you can just do:
> 
> =09python -V

For those still managing older stuff, note that this is only Python 2.0+
1.5.2 (not sure about earlier) does have sys.version and sys.hexversion,
but the tuple sys.version_info also got introduced in 2.0.

(For 2.0, 1.6 may also be valid but I generally ignore that release :-))

--
-- David
-- 
/-----------------------------------------------------------------------\
 \               David Bolen            \   E-mail: db3l at fitlinxx.com  /
  |             FitLinxx, Inc.            \  Phone: (203) 708-5192    |
 /  860 Canal Street, Stamford, CT  06902   \  Fax: (203) 316-5150     \
\-----------------------------------------------------------------------/

From jhg at acm.org  Sun Sep  2 12:36:48 2001
From: jhg at acm.org (Jim Garrison)
Date: Sun, 02 Sep 2001 16:36:48 GMT
Subject: Changed Zope Site Root -- Site Disappeared!  Pls Help.
References: 
Message-ID: <3B92601F.248E4B8A@acm.org>

I did as you said and searched Google Groups for _SUPPRESS_SITEROOT.
It returned NO hits (except for your message below).  Which other
archives should I be searching?

Oleg Broytmann wrote:
> 
> On Fri, 31 Aug 2001, James Garrison wrote:
> JG> I accidentally changed the Site Root setting for a Zope folder,
> JG> and now all attempts to access the folder from the admin interface
> JG> (i.e. to fix the site root) return "Zope Error - Resource Not Found".
> JG> The folder still appears in the manage UI, but I can't get to it
> JG> to fix it.
> JG>
> JG> How do I correct this problem?
> 
>    This question was answered many times in zope mailing lists. Just search
> the archive for _SUPPRESS_SITEROOT.

-- 
Jim Garrison (jhg at acm.org) 
PGP Keys at http://www.acm.org/~jhg RSA 0x04B73B7F DH 0x70738D88

From chrishbarker at home.net  Mon Sep 17 17:56:07 2001
From: chrishbarker at home.net (Chris Barker)
Date: Mon, 17 Sep 2001 14:56:07 -0700
Subject: How to sort a list?  NOT a newbie question.
References: <9o4i4h$2ql@ascc.artsci.wustl.edu>
Message-ID: <3BA67177.6F3E807A@home.net>

>In Matlab,
> complex numbers are sorted based on their magnitudes, and then by phase
> angle if the magnitudes are the same.  Comparing complex numbers using <,
> <=, >, and >= always returns false.

Hmm. this isn't a solution that would be easy to use for Python, as
Python is more general purpose, so the list sort() method has to do the
same thing as the comparison operators. Also, you can write your own
sort function, so it would not be hard to deal with complex numbers
however you wanted.

Note that NumPy sort chokes on complex numbers as well, so I suppose you
could do something like MATLAB in Numpy.

One possible solution is for list.sort() have a way to deal with
"non-sortable" objects. I've had this problem when sorting a set of
two-tuples, when the second item in the tuple was not sortable.
list.sort() would choke, even though I was happy for it to ignore the
second item.

hhhmmm...

-Chris

-- 
Christopher Barker,
Ph.D.                                                           
ChrisHBarker at home.net                 ---           ---           ---
http://members.home.net/barkerlohmann ---@@       -----@@       -----@@
                                   ------@@@     ------@@@     ------@@@
Oil Spill Modeling                ------   @    ------   @   ------   @
Water Resources Engineering       -------      ---------     --------    
Coastal and Fluvial Hydrodynamics --------------------------------------
------------------------------------------------------------------------

From amylang at zedat.fu-berlin.de  Sat Sep 15 13:18:09 2001
From: amylang at zedat.fu-berlin.de (amy)
Date: Sat, 15 Sep 2001 19:18:09 +0200
Subject: berlin (absolute newbie)
Message-ID: <9o02gp$9sqr7$1@fu-berlin.de>

hello, i am learning python and have read several documentations.
in fact, i have so many questions left that would blast the capacity of this
newsgroup, and i am wondering if there is somebody living in berlin, a bit
more familiar with python who would care to explain me some things in
realtime.....?
would be great, thanx
amy

From aleax at aleax.it  Wed Sep  5 08:23:08 2001
From: aleax at aleax.it (Alex Martelli)
Date: Wed, 5 Sep 2001 14:23:08 +0200
Subject: Suspected Unicode problem when reading from excell
References: <3b9612db$0$217$edfadb0f@dspool01.news.tele.dk>
Message-ID: <9n55fe01nsn@enews1.newsguy.com>

"maxm"  wrote in message
news:3b9612db$0$217$edfadb0f at dspool01.news.tele.dk...
    ...
>     print question, options, answerText
>
> But when I run it I get the following error:
>
> >>>  File "C:\div\uninstalled\python\excell\jensMarius.py", line 9, in ?
> >>>    print question, options, answerText
> >>>UnicodeError: ASCII encoding error: ordinal not in range(128)
>
> If I replace line 9 with this block, it prints out every question without
> Danish characters.
>
>     try:
>         print question
>     except:
>         pass
>
> So my guess is that it's caused by a problem with Danish characters.
>
> Has anybody got a possible solution?

sure,
    print question.encode('latin-1')
should work fine if your terminal is indeed using Latin-1 encoding.
Similarly, question.encode('mbcs') will work find if your screen
uses MBCS (MultiByte-Character-Set) encoding on Windows, 'cp437'
if it uses Codepage-437, and so on, and so forth.

Generally, to display Unicode strings, you must encode them in
the way that is suitable for your intended display device.  By
default, Python uses 'ascii' encoding and 'strict' error handling,
so you'll basically never get anything mis-displayed (well, hardly
ever -- the 7-bit ascii subset does tend to be OK on most kinds
of display devices, but even it can't cover ALL:-) and will get
exceptions you can trap and handle suitably, rather than missing
characters, question=marks, and so on:-).

If you DO want question-marks for "nonencodable" characters,
that's easy too:
    print question.encode('ascii','replace')
(or, use 'ignore' instead of 'replace' to have nonencodable
characters just omitted).

Alex

From chrishbarker at home.net  Fri Sep  7 18:33:24 2001
From: chrishbarker at home.net (Chris Barker)
Date: Fri, 07 Sep 2001 15:33:24 -0700
Subject: Performance of list comprehensions vs. map
References: 
Message-ID: <3B994B34.95755255@home.net>

Tim Peters wrote:
> > One more question: is it possible for a function to be
> > mutable??
> func_code has been writable for some time.  Here under 2.2a3:
> 
> >>> def f():
> ...     pass
> ...
> >>> def g():
> ...     return 666
> ...
> >>> f.func_code = g.func_code
> >>> f()
> 666

YOW!

this really makes optimizing even harder than I thought, and I always
thought it was hard.

Thanks, folks, I know I've learned a lot.

-Chris

-- 
Christopher Barker,
Ph.D.                                                           
ChrisHBarker at home.net                 ---           ---           ---
http://members.home.net/barkerlohmann ---@@       -----@@       -----@@
                                   ------@@@     ------@@@     ------@@@
Oil Spill Modeling                ------   @    ------   @   ------   @
Water Resources Engineering       -------      ---------     --------    
Coastal and Fluvial Hydrodynamics --------------------------------------
------------------------------------------------------------------------

From skip at pobox.com  Thu Sep 27 12:12:40 2001
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 27 Sep 2001 11:12:40 -0500
Subject: bsddb3 vs zodb
In-Reply-To: <20010927020213.A18855@zot.electricrain.com>
References: <3BA9A72A.1D5A6067@yahoo.com>
        <3BA9EBFD.3F7ABFFA@engcorp.com>
        <9oebkq$8k6$1@slb4.atl.mindspring.net>
        <9opu3g$8cr$1@inputplus.demon.co.uk>
        <20010927020213.A18855@zot.electricrain.com>
Message-ID: <15283.20472.419234.846833@beluga.mojam.com>

    Greg> True.  It's worth noting however that BerkeleyDB 3.3 adds support
    Greg> for automated "secondary indexing" which really gives it a
    Greg> significant chunk of capabilities that people often end up using
    Greg> for full fledged relational databases for. 

Can you explain what "secondary indexing" is?  I was never aware I needed it
and am using relational databases because of it. ;-)

Thx,

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/

From max at alcyone.com  Thu Sep  6 11:35:24 2001
From: max at alcyone.com (Erik Max Francis)
Date: Thu, 06 Sep 2001 08:35:24 -0700
Subject: dictionary and __getattr__
References: 
Message-ID: <3B9797BC.3D667896@alcyone.com>

Harald Kirsch wrote:

> Wouldn't it be nice if this would work:
> 
>   d = {'x': 1}
>   print d.x
> 
> i.e. every entry in a dictionary is also an attribute of the
> dictionary itself.

Why would it?

Furthermore, what do you do in the not so obvious cases?  What happens
if your key is a number?  Or contains spaces?  Or worse yet, is a tuple?

-- 
 Erik Max Francis / max at alcyone.com / http://www.alcyone.com/max/
 __ San Jose, CA, US / 37 20 N 121 53 W / ICQ16063900 / &tSftDotIotE
/  \ In principle I am against principles.
\__/ Tristan Tzara
    Kepler's laws / http://www.alcyone.com/max/physics/kepler/
 A proof of Kepler's laws.

From markus at schabi.de  Mon Sep  3 13:34:55 2001
From: markus at schabi.de (Markus Schaber)
Date: Mon, 3 Sep 2001 19:34:55 +0200
Subject: 3-arg float pow()
References:  <3b938b3c.1110872@nntp.sprynet.com>
Message-ID: <2078976.8kZL3ZeAuk@lunix.schabi.de>

Hi,

David C. Ullrich  schrub:

> Seems like pow(3., 500., 7.) can't possibly do anything except just
> 3.**500. % 7(???), hence the random nature of the result and the utter
> uselessness. 

The trick is that it is a exponential function with large result modulo 
a small number. (such operations are e. G. used in the RSA crypto 
algorithm)

When calculating the exponential function using software emulation (as 
I know of no decent hardware support for long Integers), you have more 
or less a loop of multiplications or so (depending how optimized your 
algorithm is).

One optimized algorithm is to split the 500 into powers of two, so 
3**500 gets to 3**(256 + 128 + 64 + 32 + 16 + 4) == (3**256) * (3**128) 
* (3**64) * (3**32) * (3**16) * (3**4). As you see, you can generate 
the bracketed values by repeatedly multiplying the number with itsself 
(which is rather fast) and then multiplying all those values. In a 
computer, you can quite optimize this, as the 500 is already given in 
binary. Thus one can iterate like the following:

def simple(base, exp, modulo):
  res = 1L
  while exp != 0L:
      if exp & 1L:
          res *= base
      exp >>=1L
      base *= base
  return res%modulo

This gives 9 rounds with two comparisons, one shift and maximum two 
multiplications per loop, thus a maximum of 45 operations compared to 
500 when using simple plain loop.

The problem is when the intermetiate number gets rather large (which is 
the case here, we get 3**500 == 
36360291795869936842385267079543319118023385026001623040346035832580600191583895484198508262979388783308179702534403855752855931517013066142992430916562025780021771247847643450125342836565813209972590371590152578728008385990139795377610001). 
Using dynamically sized numbers (as our long integers are), this can 
get rather big (and thus memory- and cpu-intensive) compared to the 
final result 2.

But as we calculate modulo 7, we can apply the modulo after every 
single step of shifting, and so keep the numbers small (which 
is much faster given some numbers, and uses much less memory)

def optimized(base, exp, modulo):
  res = 1L
  while exp != 0L:
      if exp & 1L:
          res *= base
          res %= modulo
      exp >>=1L
      base *= base
      base %= modulo
  return res

Especially when calculating lots of numbers (such as applying this to a 
list or matrix), this can save some megabyte intermediate storage.

A test like 

start = time.clock()
for i in xrange(1000):
  void = simple(3L,5000L,7L)
stend = time.clock()
print 'simple:',round(stend-start,2)

gives 7.28 seconds for the simple and 0.24 seconds for the 
modulo-optimized version on my machine.

On the other side this doesn't apply when using small integers (as they 
don't expand in size), and doesn't gain much when the exponental result 
and the modulo factor are about the same size. E. G. using 50 as exp in 
the example above gives 0.09 seconds in the simple and 0.13 seconds in 
the optimized version due to the additional modulo operations. 

Additionally, the second algorithm can be rewritten to calculate the 
result using ordinary integers (simply remove all the "L"s in the def 
and at the call), and this way only needs 0.05 seconds, whereas the 
first algorithm gives an OverflowError. A math library coder could use 
some heuristics to dynamically decide which algorithm to use.

I ran an additional test, calculating pow(3,5000000,7), and the 
unoptimized version (all Longs) needs about 50 seconds for _one_ loop, 
whereas the optimized version needs for _1000_ loops 0.35 seconds using 
longs, and 0.13 seconds using integers. Btw, the builtin pow function 
needs 0.15 and 0.01 seconds

But I don't know whether this trick is usable in floating point, as 
most floating point is done in hardware nowadays. I can imagine that 
some FPU have machine commands to gain additional speed and maybe 
exactness this way.

Another point may be that when processing arrays or matrices, a 
sophisticated programmer may use MMX, 3DNow!, ISSE or AltiVec to gain 
speed by processing something in parallel, but I'm afraid this would be 
not so easy to incorporate in python, because there numbers are stored 
as references to objects.

PS: I'm away for a week from tomorrow on, so please be patient with my 
answers to your comments / questions.

markus
-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From news at davidglasser.net  Wed Sep 26 18:00:39 2001
From: news at davidglasser.net (David Glasser)
Date: Wed, 26 Sep 2001 18:00:39 -0400
Subject: Sort documentation inaccurate?
References: <3BB16F36.A7BAE259@cygnus-software.com>
Message-ID: <1f0csar.16wevqq1sza16oN%news@davidglasser.net>

Bruce Dawson  wrote:

> >>> mylist = [1, 2, 3, 5, 4, 6]
> >>> def compare1(x, y):
> ...  return x < y
> ...
> >>> mylist.sort(compare1)
> >>> mylist
> [1, 2, 3, 5, 4, 6]

The comparison "x < y" can return two values: 1 if x < y, and 0 if
x >= y.  But a sort function really needs to be more specific,
differentiating between x < y, x > y, and x == y.  The standard for sort
functions, based on C's strcmp, is to return:

   -1 if x < y
   0  if x == y
   +1  if x > y

(It appears that any negative value is as good as -1, and any positive
for +1, but the documentation just say those specific values.)  This is,
as you said, so a function can do something along the lines of "return x
- y".

The really good news, though, is that you can ignore most of this by
using Python's cmp function.  For example, to sort by absolute value:

>>> x = [1, 0, -2, 52, -32, 4]
>>> def abssort(x, y):
...    return cmp(abs(x), abs(y))
... 
>>> x.sort(abssort)
>>> x
[0, 1, -2, 4, -32, 52]

-- 
David Glasser
news at davidglasser.net               http://www.davidglasser.net/

From martin.franklin at westgeo.com  Wed Sep  5 12:08:11 2001
From: martin.franklin at westgeo.com (Martin Franklin)
Date: Wed, 5 Sep 2001 17:08:11 +0100
Subject: Widget tooltips
References: 
Message-ID: <9n5ihb$1ikk$1@mail1.wg.waii.com>

Jo?o Alfredo wrote:

> Hi all,
> 
> Does Tkinter supports widget tooltips?? If yes, how??

The Pmw extensions do have balloon help....  check the vaults

> 
> Thanks in advance.
> 
> []'s
> Jo?o Alfredo
> 
> 
> 
> 
> _________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.com address at http://mail.yahoo.com
> 
> 
> 

From mmhamze at pleiades.net  Wed Sep  5 09:48:57 2001
From: mmhamze at pleiades.net (Maan M. Hamze)
Date: Wed, 5 Sep 2001 08:48:57 -0500
Subject: Selecting varray using python
References: 
Message-ID: 

Amin
You lost me here.  Are you sure that DCOracle works with Oracle 8i?  I know
that DCOracle2 does.
Maan

"Amin Abdulghani"  wrote in message
news:f5b09a2f.0109041358.20f1290d at posting.google.com...
> Hi,
>
> I have recently installed DCOracle 1.3.2 to interface Oracle 8i
> with python. The problem I seem to be facing is trying to access
> a varray column using the interface. Does anyone have anyone

From greg at cosc.canterbury.ac.nz  Thu Sep 13 18:59:57 2001
From: greg at cosc.canterbury.ac.nz (Greg Ewing)
Date: Fri, 14 Sep 2001 10:59:57 +1200
Subject: Proposed PEP for a Conditional Expression
References:  <6qvgire4bk.fsf@abnoba.intevation.de> <9nk3jd$4lc$1@glue.ucr.edu> <9nnsa3$bjl$1@news.mathworks.com>  <3BA00239.DECE6412@cosc.canterbury.ac.nz>  <5xXn7.2447$w62.1612177@news1.denver1.co.home.com> 
Message-ID: <3BA13A6D.BA6E1922@cosc.canterbury.ac.nz>

Ken Seehof wrote:
> 
> Also, I would propose that ... else None should be implicit.
>    >>> print 'eeek' if pi == 3
>    None
> 
> But ... people could easily be confused and misinterpret the syntax as:
>     if  [ else  ]

That's a good argument for making the else mandatory.
It's less easy to misinterpret

   print 'eeek' if pi == 3 else None

It would be even clearer if parentheses were required:

   print ('eeek' if pi == 3 else None)

So I suggest that parentheses always be required around
if..else expressions. That would clear up any potential
confusion in list comprehensions, and anywhere else that
it might occur.

-- 
Greg Ewing, Computer Science Dept, University of Canterbury,	  
Christchurch, New Zealand
To get my email address, please visit my web page:	  
http://www.cosc.canterbury.ac.nz/~greg

From adina_levin at mindspring.com  Sun Sep 30 14:21:57 2001
From: adina_levin at mindspring.com (adina_levin at mindspring.com)
Date: Sun, 30 Sep 2001 13:21:57 -0500
Subject: newbie question: help with polymorphism and/or programming style
Message-ID: <9p7o8l$4q5$1@slb2.atl.mindspring.net>

Hello, Pythonites.

I am teaching myself python programming, and have created a toy storefront
program.

If the customer wants to pay with cash, the program should return change. If
the customer wants to pay using a credit card, the program should validate
the customer's ability to pay, and return an approval.

Several questions regarding programming style:

a) Is it desirable to replace the "if" statement in paymenthandler with
subclasses, PayCash(Payment) and PayCredit(Payment).  If so, doesn't that
just push the "if" statement upstream, where you PayCash() if the customer
says she wants to pay cash?  I am clearly missing something!! :-(

b) Is it bad style to return different kinds of information, depending on
whether the customer pays with cash or credit? If so, how should this be
handled cleanly?

c) Any other programming style problems?

This is a toy, so no reason to comment on lack of full detail in the
simulation.

class Payment:
    def __init__(self):
        self.payobject=Customer().getpaymentinput()

    def payhandler(self,sum):
        self.sum=sum
        if self.payobject.paytype == "cash":
            result=self.payobject.cashamount-self.sum
            print result

        elif self.payobject.paytype == "credit":
            self.crednum=self.payobject.crednum
            result=Creditcheck().creditapprove(self)

        return result

From jkraska at san.rr.com  Sun Sep  2 14:25:36 2001
From: jkraska at san.rr.com (Courageous)
Date: Sun, 02 Sep 2001 18:25:36 GMT
Subject: Stackless Python and Python 2.x
References:  
Message-ID: 

>The advantages over real threads are enormous:
> - lightweight

This can be a real issue if you begin running enough
threads where context-switching speed begins to matter.

> - system level locks never needed
> - user level locks rarely needed
>
>The only downside is relatively minor - I have to make
>sure that one "thread" doesn't monopolize the CPU.

One alternative is to use one or more real threads to
manage your continuation-threads. As your executive
thread is preemptively threaded, it can possibly
terminate unresponsive c-threads.

C//

From db3l at fitlinxx.com  Fri Sep 28 20:28:12 2001
From: db3l at fitlinxx.com (David Bolen)
Date: 28 Sep 2001 20:28:12 -0400
Subject: stdin broken on Win2K?
References: <43u9rtsgorpj5fh4r07hkoakkh9bkh2u22@4ax.com>
Message-ID: 

Dale Strickland-Clark  writes:

> This:
> 
> # stdintest.py
> # Copy stdin to stdout
> 
> import sys
> l = sys.stdin.readline()
> while l:
> 	print l,
> 	l = sys.stdin.readline()
> 
> 
> doesn' work from the Win2K command prompt in either of the following
> cases:
> 
> stdintest  type source.txt | stdintest
> 
> However, if you don't redirect stdin, it will happily reflect console
> input to the console.

At least NT has a bug in CMD.EXE when using automatic execution of
Python scripts via the PATHEXT variable and command line redirection.
Perhaps it's still present in Win2K's CMD.EXE.

What happens if you use "python stdintest.py" rather than just
"stdintest" in your command?

--
-- David
-- 
/-----------------------------------------------------------------------\
 \               David Bolen            \   E-mail: db3l at fitlinxx.com  /
  |             FitLinxx, Inc.            \  Phone: (203) 708-5192    |
 /  860 Canal Street, Stamford, CT  06902   \  Fax: (203) 316-5150     \
\-----------------------------------------------------------------------/

From hnowak at cuci.nl  Mon Sep  3 04:27:03 2001
From: hnowak at cuci.nl (Hans Nowak)
Date: Mon, 3 Sep 2001 10:27:03 +0200
Subject: Can I build a dictonary with a list-comprehension?
Message-ID: <3B95A738@twigger.nl>

>===== Original Message From "Marcin 'Qrczak' Kowalczyk"  
=====
>Fri, 31 Aug 2001 15:48:05 +0200, spex66  pisze:
>
>> dict = {}
>> LIST = [...] #What you want
>> [dict.update({x: 'spam'}) for x in LIST]
>
>Using list comprehensions when the result is ignored is misleading
>and inefficient. A for loop is better.
>
>When there is only a single value, insted of update it's simpler to
>use __setitem__.
>
>In general, where items come in (key,value) pairs, dictionary can be
>built like this:
>
>dict = {}
>LIST = [...]
>for k, v in LIST:
>    dict[k] = v
>
>and there is no simple builtin list-comprehension-like syntax in the
>form of an expression (but you can write a function to convert a list
>to a dictionary).

Un an entirely unrelated note, maybe there should be dictionary 
comprehensions, too... :)

{ k,v for k,v in dict if type(v) == type("") }

--Hans Nowak

From digitig at cix.co.uk  Sun Sep  9 13:48:00 2001
From: digitig at cix.co.uk (Tim Rowe)
Date: Sun, 9 Sep 2001 18:48 +0100 (BST)
Subject: constant in python?
References: <7xsneoijz7.fsf@ruckus.brouhaha.com>
Message-ID: 

In article <7xsneoijz7.fsf at ruckus.brouhaha.com>, phr-n2001 at nightsong.com 
(Paul Rubin) wrote:

> "Alex Martelli"  writes:
> > > problem with enforcing privacy is that the designer can seldom
> > > anticipate all of the possible uses of their code and placing 
> > > arbitrary
> > > access restriction can make it impossible for the user to accomplish
> > > their task.
> > 
> > Hear, hear!  Designers aren't omniscient and a language that lets
> > me workaround a limitation in the design of a framework or library
> > I need to use is just what I need.
> 
> The trouble is, the very existence of a workaround is sometimes itself
> a limitation, e.g. in implementing an applet sandbox.
> 
> > > Python is a general purpose programming language and its design 
> > > should
> > > not be significantly compromised to make a particular (uncommon) 
> > > usage
> > > more convenient i.e. security environments.
> > 
> > Yep.  Besides, rexec and Bastion (could use some spiffying up,
> > but) are pretty good for this.
> 
> I'll check into those.  However, a true general purpose language
> should be useable in all environments.  

I don't much believe in general purpose languages. The trouble is, a 
language that can do everything won't be very good at anything. Be aware 
of the strengths and weaknesses of different languages, have more than one 
string to your bow, and know how to choose which one to use. I doubt if 
Python could ever be the language of choice for real-time operating system 
design, embedded control or safety critical for instance, and should 
resist adding complication in an attempt to move into those fields. IMHO 
Python development should play to its strengths and not try to turn it 
simultaneously into Haskell, Ada, Forth, C++ and Smalltalk!

From qrczak at knm.org.pl  Tue Sep  4 08:05:37 2001
From: qrczak at knm.org.pl (Marcin 'Qrczak' Kowalczyk)
Date: 4 Sep 2001 12:05:37 GMT
Subject: Is 0 > None?? (fwd) (fwd)
References:  
Message-ID: 

Tue, 4 Sep 2001 10:01:02 +0200, Alex Martelli  pisze:

> Comparison issues, and sorting of heterogeneous lists in
> particular, ARE central to the new noncomparable behavior
> of complex numbers.  I see no solution to THAT one, save:
>     a. either drop the pretense that it makes sense to
>         compare heterogeneous entities, or
>     b. regress the change that makes it illegal to compare
>         complex numbers.

c. Have two kinds of comparison, homogeneous and heterogeneous.
This solves the complex numbers problem, but unfortunately not the
str <-> unicode problem.

The real problem is that if Unicode strings and byte strings are
treated like alternative representation of the same data (as numeric
types are), i.e. they compare equal if they represent the same text,
then there are two incompatible orders involved: lexicographically by
Unicode character values and byte values. It would break transitiveness
of comparisons.

Actually it does break it if something othar than ASCII or Latin1 is
chosen as the default encoding!

    '?' > '?'
    '?'.decode('iso-8859-2') < u'\u00D1' < '?'.decode('iso-8859-2')
    '?' < u'\u00D1' < '?'   # when 'iso-8859-2' is the default

Since byte strings and Unicode strings can't be reliably compared
anyway, a solution would be to drop their equivalence, treat as
separate types, let 'A' != u'A', require explicit coercions in either
direction for homogeneous comparisons.

Alternatively comparison could consistently use the Unicode ordering -
but it's unworkable in practice, even with a sane default (not ASCII).
Byte strings are supposed to be able to represent binary data as well,
and it's inefficient.

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZAST?PCZA
QRCZAK

From News at eduplay.intensive.co.no.muppets.uk  Fri Sep 28 14:36:18 2001
From: News at eduplay.intensive.co.no.muppets.uk (Ben Ainsworth)
Date: Fri, 28 Sep 2001 19:36:18 +0100
Subject: RM Connect and Python
Message-ID: <3bb4c322$1_1@lon-news.intensive.net>

I'm trying to persuade the school I teach at to place Python on the network
as I'd like a real programming language for my teaching. However the IT
staff tell me they have problems with many programs and the RM Connect
software they use for security. Does anyone have experience of installing
Python on a network that uses RM Connect?

From flognat at flognat.myip.org  Sat Sep 15 15:30:17 2001
From: flognat at flognat.myip.org (Andrew Markebo)
Date: Sat, 15 Sep 2001 19:30:17 GMT
Subject: Why Tcl/Tk
References: <3ba27ba1_8@news.newsgroups.com>
Message-ID: 

I have seen a couple of answers to this question and I would like to
throw in an answer.. 

Basically Python and Tkinter existed before you could even think of it
on windows! What happened was that someone who needed good GUI-stuff
did Tkinter.. And it went into python..  

Later on python started to be able to compile on dos/windows, but no
tcl/tk.. 

Later on tcl/tk was ported to windows, and wee it was no big problem
getting Tkinter to work.. And it is now in everybodys (well
almost.. ok.. my) spine.. 

Meanwhile regarding GTK+ and so on, it is simple to get it into python
I think... just get a couple together and do a good job and it might
slip into the dist and get used.. 

        /Andy

/ "Janos Blazi"  wrote:
| My question has probably been discussed for ages. Why uses Python Tcl/Tk as
| de facto GUI toolkit?
| I think that both GTK+ and Qt are generally considered more powerful than
| Tcl/Tk and I was very much surprised that in fact bindings for both
| libraries exist for Python.

-- 
 The eye of the beholder rests on the beauty!

From dale at riverhall.NOSPAMco.uk  Thu Sep 27 11:00:14 2001
From: dale at riverhall.NOSPAMco.uk (Dale Strickland-Clark)
Date: Thu, 27 Sep 2001 16:00:14 +0100
Subject: Class mutation
References: <8626rt838oe59d1njrtrisccm0oe02shvf@4ax.com> <9ov336$fpp6v$1@ID-59885.news.dfncis.de>  <1015343.vhalqRGMn8@lunix.schabi.de>
Message-ID: 

>But it exactly does what you want. It assigns the new class to your job 
>object.
>
It does indeed do exactly what I want but if there is a chance of the
feature being removed, it's a bit of a risk using it.

Thanks for your help, however, we've gone for a state attribute
instead. Tthe Job class will contain all the methods needed in the
active state as well.

--
Dale Strickland-Clark
Riverhall Systems Ltd

From logiplexsoftware at earthlink.net  Wed Sep 12 18:52:41 2001
From: logiplexsoftware at earthlink.net (Cliff Wells)
Date: Wed, 12 Sep 2001 15:52:41 -0700
Subject: Parrot for real?
In-Reply-To: <9nonos$4ms@gap.cco.caltech.edu>
References: <3B9F8AD0.94C81526@lindbergs.org>  <9nonos$4ms@gap.cco.caltech.edu>
Message-ID: <01091215524105.01493@logiplex1.logiplex.net>

On Wednesday 12 September 2001 15:25, Nathaniel Gray wrote:

> http://mail.python.org/pipermail/python-dev/2001-July/016406.html

!!!!!

-- 
Cliff Wells
Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 x308
(800) 735-0555 x308

From phr-n2001 at nightsong.com  Tue Sep 25 14:26:37 2001
From: phr-n2001 at nightsong.com (Paul Rubin)
Date: 25 Sep 2001 11:26:37 -0700
Subject: Proposal: add vector arithmetic to array module
References: 
Message-ID: <7xy9n3w2hu.fsf@ruckus.brouhaha.com>

"Mike C. Fletcher"  writes:
> Numeric is becoming a very widely used module, so if there is something
> going into the core, it would be my vote.  However, I'd still like to see a
> better mechanism for distributing extensions (e.g. auto-downloading signed
> packages from a Zope server somewhere) so that the list of "included"
> modules can _shrink_, rather than grow.
> 
> But then everyone wants that,

I certainly don't want any automated software downloads happening
without my permission, signed code or not.  Also, just because code is
signed doesn't mean I trust whoever signed it.  I'm generally willing
to trust the maintainers of highly visible systems (e.g. the main
Python distribution) if I'm getting the source code.  But if it's
something infrequently used from a random developer who I don't know,
I'll usually inspect the source code before compiling it, which takes
quite a bit of time.  I do *not* want dozens of packages signed by
unknown random distributors installed on my machine automatically.

From ungrzr2 at ubatxbat.pbz  Thu Sep 20 03:50:47 2001
From: ungrzr2 at ubatxbat.pbz ({-- Rot13 - Hateme)
Date: 20 Sep 2001 07:50:47 GMT
Subject: simple example of mimelib?  and embedding (not attaching) images in email sent with python.
References: <97ae44ee.0108140526.63a22745@posting.google.com>   
Message-ID: 

Speaking of email, has anyone done a module for
threading emails according to the message-id and
subject? something as described in 
http://www.jwz.org/doc/threading.html

From sarcangeli at montrouge.sema.slb.com  Mon Sep 17 05:38:01 2001
From: sarcangeli at montrouge.sema.slb.com (Silvio Arcangeli)
Date: Mon, 17 Sep 2001 10:38:01 +0100
Subject: optional arguments
Message-ID: <4.3.2.7.2.20010917103131.00b0d8b0@popper.montrouge.tt.slb.com>

Hello everybody,
sorry for this question that may seem silly.
I have an object whose __init__  looks like the following:

class Connection:
	def __init__(self, ip=def_ip, port=def_port)
		...

I have to call two different functions when the object is instantied like
c=Connection()
and when it is instantiated like
c=Connection(def_ip, def_port)

how can I tell wheter no arguments were passed from the user or whether 
they were passed but they were just like the default values?

Silvio.

From tim.one at home.com  Wed Sep 26 00:55:38 2001
From: tim.one at home.com (Tim Peters)
Date: Wed, 26 Sep 2001 00:55:38 -0400
Subject: Proposal: add vector arithmetic to array module
In-Reply-To: <7x4rprs2cl.fsf@ruckus.brouhaha.com>
Message-ID: 

[Tim]
> Use NumPy -- can't be suppressed .  Why do you think
> NumPy is a big package?  Doing this right is neither simple nor lean,
> and as soon as one array op is added, the rest are inevitable.

[Paul Rubin]
> Huh?  Adding pointwise addition means you have to add eigenvalues?

I hope you didn't believe that merits a response <0.5 wink>.

> The reason I don't want to use NumPy is that it isn't included in
> standard Python distributions.  It's yet another thing for the user
> to download, and it's maintained and distributed by a separate group
> of people than the Python maintainers.  All in all, it's harder to
> deal with and there's more ways to go wrong.

That's all true of every module that's not in the core distribution.  If the
NumPy maintainers really wanted it in the core, I bet they could prevail --
but I doubt the current crop of core Python maintainers has the bandwidth to
take this over from them (the PythonLabs crew does not), let alone to
reinvent it.  So "really want" includes volunteering ongoing work too.

> If NumPy became part of standard Python, then I'd happily use it.

Same here.

heck-i'd-use-perl-again-if-it-were-part-of-core-python-ly y'rs
    - tim

From ignacio at openservices.net  Tue Sep 18 04:49:30 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Tue, 18 Sep 2001 04:49:30 -0400 (EDT)
Subject: re source code
In-Reply-To: <025501c1401e$b13854a0$a500a8c0@moonqzie>
Message-ID: 

On Tue, 18 Sep 2001, Carlos Gaston Alvarez wrote:

> I want to read re source code.
> I want to know why it is more tolerant to .* than to .*?  and so on. The
> final documentation is the source. I want that.

Feel free to download the source tarball and extract the files from that.

-- 
Ignacio Vazquez-Abrams  

From jjl at pobox.com  Sun Sep 16 15:08:32 2001
From: jjl at pobox.com (John J. Lee)
Date: Sun, 16 Sep 2001 20:08:32 +0100
Subject: Python as ActiveScripting language for IE
In-Reply-To: <3ba449d1.4461765@news.t-online.de>
References: <3ba449d1.4461765@news.t-online.de>
Message-ID: 

On Sun, 16 Sep 2001, Gerson Kurz wrote:

> I'm using Python as client-side scripting language in IE. It works
> really great! But, when I do this
[...]
> it seems that the Python runtime gets unloaded between the first two
> steps, only to be loaded back again later. The problem is that loading
[...]

There must (?) a good solution to this, but I don't know it.

I presume Java doesn't do this?  If so, since you'll have to install
Python on the clients anyway, you may as well install Java as well, and
run Jython instead, if that works around the problem.  When you figure
out how to get CPython to stick around, it should be easy to move back
again.

You may even be able to avoid any need to manually install things on the
client side, if the version of Java installed is good enough to let
Jython work.

John

From uselesspython at yahoo.com  Mon Sep  3 20:11:20 2001
From: uselesspython at yahoo.com (Rob)
Date: Tue, 04 Sep 2001 00:11:20 GMT
Subject: Small program trouble WAS Re: Small proram troble
References: 
Message-ID: <3B941BF2.4020006@yahoo.com>

Ignacio Vazquez-Abrams wrote:

> On 3 Sep 2001, Patio87 wrote:
> 
> 
>>I have a problem with this simple program but im very new to python and this is
>>the biggest program i have written. Now I think the problem is the while loop
>>but im not sure if someone could take a look at this it would be apprecitaed
>>
> 
> Yikes. Here's my fixed version:
> 
> ---

And here's my fixed version of the fixed version:

import sys

choice = 0

def print_options():
    print "Options:"
    print "'1' Print Options"
    print "'2' Add numbers"
    print "'3' Subtract numbers"
    print "'4' Multiply number"
    print "'5' Divide number"
    print "'6' Exit"

print_options()

while choice != 6:
    choice = raw_input("What would thou like to do?")
    if choice == "1":
        print_options()
    elif choice == "2":
        add = input("What number would you like to add?")
        add2 = input("What other number do you want to add?")
        print "The awnser is", add + add2
    elif choice == "3":
        sub = input("What number do you want to subtract?")
        sub2 = input("What 2nd number do you want to subtract?")
        print "Your awnser is,", sub + sub2
    elif choice == "4":
        mul = input("What number do you want to multiply")
        mul2 = input("What 2nd number do you want to multiply")
        print "Your multiplicated number is", mul * mul2
    elif choice == "5":
        div = input("What is your dividend?")
        div2 = input("What is your numerator?")
        print "Your awnser is", div/div2
    elif choice == "6":
        print "thanks for using my program"
        sys.exit()

ooh-this-is-fun-ly,
Rob
-- 
A {} is a terrible thing to waste.
Useless Python!
http://www.lowerstandard.com/python

From sholden at holdenweb.com  Mon Sep 10 19:50:05 2001
From: sholden at holdenweb.com (Steve Holden)
Date: Mon, 10 Sep 2001 19:50:05 -0400
Subject: [OT] Strange IE5.5 Caching Behavior
Message-ID: 

Sorry about this post being off-topic, but c.l.py is the largest collection
of web-heads I have easy access to. If you know nothing about HTTP, please
ignore this.

I'm serving static content, looking at the client's "If-Modified-Since"
header, and returning a 304 response if the file's Last-Modified date is
before that. When I serve the content I include a "Last-Modified:" header to
identify the age of the file.

For some reason the incoming "If-Modified-Since" headers *always* seem to be
three minutes and 27 seconds before the "Last-Modified:" date of the file.
I've searched Google, and Microsoft's Knowledge Base, without finding
anything relevant.

If anyone knows what's causing this (and even better, how to fix it) I'd be
very grateful for a pointer.

regards
 Steve
--
http://www.holdenweb.com/

From markus at schabi.de  Wed Sep 19 14:13:06 2001
From: markus at schabi.de (Markus Schaber)
Date: Wed, 19 Sep 2001 20:13:06 +0200
Subject: Direct TK interface
References: <2764949.5mLc6kNg2l@lunix.schabi.de> <23891c90.0109190625.1a15d464@posting.google.com>
Message-ID: <1442950.reEdlvqk35@lunix.schabi.de>

Paul Boddie  schrub:

> Markus Schaber  wrote in message
> news:<2764949.5mLc6kNg2l at lunix.schabi.de>...
>> Hi,
>> 
>> I was just wondering whether it is possible (and worth in sense of
>> speed etc.) to directly interface TK into python (without using the
>> TCL interpreter inbetween).
> 
> What about "Tkinter 3000" from Pythonware (http://www.pythonware.com)?
> Isn't this supposed to have similar goals, or is the idea to have the
> same API but to use a different implementation technology?

I read the page, and it sounded promising (although the documentation 
doesn't really go into technical details).

My two motivations were efficiency and possible elimination of the 
(IMHO) ugly and not python-like Tkinter.StringVar() construct (which is 
not necessary in TCL/TK because of the direct integration, and might 
perhaps be implemented using the new get/set attributes.)

markus
-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From aleax at aleax.it  Wed Sep 12 08:04:26 2001
From: aleax at aleax.it (Alex Martelli)
Date: Wed, 12 Sep 2001 14:04:26 +0200
Subject: python equivalent of wantarray() : newbie
References: 
Message-ID: <9nnj0a02gs5@enews1.newsguy.com>

"Karthik Gurumurthy"  wrote in message
news:mailman.1000286203.3187.python-list at python.org...
>
> please bear with me, am still learning.
>
> is there a way to determine whether a return value is expected from a
> method?
> like the way wantarray() works in perl.

No, because Python accepts just about anything the method
wants to return.  Perl is very context-driven, Python is
not: whatever object the method wants to return, including
None, will typically do, since all objects are first-class.

It's possible that _operations_ *later* applied on the
returned value may imply certain "desires" regarding said
value, but that doesn't really change the context-free
operation of Python.

> perl can determine the type of the variable used
>
> @array = call()//so it's list context so call can return a list
> $var = call()//scalar context so call can return say a string.
>
> But can python determine the same?? i guess it can't and that's why we
don't
> have a wantarray() equivalent in python??

Right.  Even if you could magically determined that an indexing
call()[something] was later to be applied, this STILL wouldn't
tell you whether one 'wants' a list or a string -- both are quite
able to be indexed (and so are dictionaries, other built-in
objects such as arrays, and of course many user-defined classes).
So, again, things ARE basically context-free.

Alex

From lud at sogetek.fr  Wed Sep  5 08:57:46 2001
From: lud at sogetek.fr (lud)
Date: Wed, 5 Sep 2001 14:57:46 +0200
Subject: a simple question for writtting module
Message-ID: 

Hi !!

my problem :

first i write in python :
        import mymodule
        data="is a test"
        mymodule.show()

###################
now in c :
static PyObject *
mymodule_show(PyObject * self, PyObject *args)
{
/*bla bla bla ....*/
}
so i want get the value of data without transmit her in the call of the
function show

any idea ?

thx, Ludo

From aleax at aleax.it  Mon Sep 17 07:06:04 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 17 Sep 2001 13:06:04 +0200
Subject: optional arguments
References: 
Message-ID: <9o4les02kg6@enews4.newsguy.com>

"Silvio Arcangeli"  wrote in message
news:mailman.1000716020.11396.python-list at python.org...
> Hello everybody,
> sorry for this question that may seem silly.
> I have an object whose __init__  looks like the following:
>
> class Connection:
> def __init__(self, ip=def_ip, port=def_port)
> ...
>
> I have to call two different functions when the object is instantied like
> c=Connection()
> and when it is instantiated like
> c=Connection(def_ip, def_port)
>
> how can I tell wheter no arguments were passed from the user or whether
> they were passed but they were just like the default values?

By *NOT* using, as default values for the arguments, values
that could indeed equally well be passed by the client-code.

class Connection:
    class __Boo: pass
    __None = __Boo()
    def __init__(self, ip=__None, port=__None):
        if ip is self.__None:
            print "ip was NOT passed"
        else: print "ip was passed as",ip

etc, etc.

See http://www.penguin.it/pipermail/python/ if you'd
like help and/or discussion about Python in Italian.

Alex

From skip at pobox.com  Mon Sep 24 17:09:17 2001
From: skip at pobox.com (Skip Montanaro)
Date: Mon, 24 Sep 2001 16:09:17 -0500
Subject: Why so few Python jobs?
In-Reply-To: 
References: <20010924204805.C22856@software.plasmon>

Message-ID: <15279.41213.664043.82516@beluga.mojam.com>

    daveb> Indentation is the first and most important indicator of block
    daveb> structure, followed by a very distant 2nd place contestant, the
    daveb> block delimiters, which is why people commit those "classic" bugs
    daveb> I mentioned above.

And why many local C style guides require you to always use braces with
if/while/for/do etc, even when there is only a single statement in the
block... .

Cheers,

Skip

From gbourgeois at silicom.fr  Tue Sep  4 06:59:40 2001
From: gbourgeois at silicom.fr (Gilles Bourgeois)
Date: Tue, 04 Sep 2001 11:59:40 +0100
Subject: tree widget in python
Message-ID: <3B94B41C.4CDB3B87@silicom.fr>

hi ,from france
does anyone gnows if tree widget exists in wxpython
I need a kind of expandable graphical tree  (like when brosing a file
system with the Windoze file explorer)

My aim is to use a tree to have a expandable view of a C structure ;

this could be :
typedef {
 char* toto;
 struct titi {
 int x;
 int y;}
}S

and I want to  give a graphical representation of S, the user then may
access to all fields of the S 'C structure' and fill in the parameter.

TIA
gilles

From qrczak at knm.org.pl  Tue Sep  4 07:19:33 2001
From: qrczak at knm.org.pl (Marcin 'Qrczak' Kowalczyk)
Date: 4 Sep 2001 11:19:33 GMT
Subject: 3-arg float pow()
References: 
Message-ID: 

Mon, 3 Sep 2001 16:51:19 -0400, Tim Peters  pisze:

> This is *less* accurate than using a good-quality libm pow() (which
> should have worst-case final error strictly less than 1 ULP), so
> current CVS Python uses the libm pow() instead.  The last few bits
> may differ -- or as many as the last 15-or-so bits if the platform
> libm pow() truly sucks.

I would expect pow to use multiplication when the exponent is an
integer (with a signle division if it's negative), and the libm
pow or equivalently exp(b*ln(a)) if the exponent is a float.
All independently of the base.

So (-3)**2 would be defined, but (-3)**2.0 would be not.
And 3**(-2) should return a rational.

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZAST?PCZA
QRCZAK

From db3l at fitlinxx.com  Wed Sep 19 19:27:47 2001
From: db3l at fitlinxx.com (David Bolen)
Date: 19 Sep 2001 19:27:47 -0400
Subject: Size in bytes of a dictionary
References:  <3BA8D294.1D974F89@home.com>
Message-ID: 

Don O'Donnell  writes:

> Also beware of automatic interning of strings.  Of course this won't be
> an issue with your key strings, since they must be unique, but duplicate
> value strings may use the same memory location.  I'm not sure under what
> conditions auto-intern takes place but it seems to be related to the
> length of the string.  Here's a little test I just ran:

It's of course potentially version specific, but I think in all recent
(1.5.2+) variants of CPython the interning rule is that it must be a
string consisting soley of alphanumerics and the underscore.  Length
does not appear to be a factor.  (See compile.c in the CPython
source).

--
-- David
-- 
/-----------------------------------------------------------------------\
 \               David Bolen            \   E-mail: db3l at fitlinxx.com  /
  |             FitLinxx, Inc.            \  Phone: (203) 708-5192    |
 /  860 Canal Street, Stamford, CT  06902   \  Fax: (203) 316-5150     \
\-----------------------------------------------------------------------/

From shuggy at volcanomail.com  Mon Sep  3 00:51:25 2001
From: shuggy at volcanomail.com (rob shugg)
Date: 2 Sep 2001 21:51:25 -0700
Subject: Tkinter and a clock
Message-ID: <62a98d55.0109022051.7d323e1a@posting.google.com>

I have an application where I need to display a clock during a data
acquisition operation. The clock needs to display seconds and I need
to be able to start stop and reset it like a stopwatch. I have been
reading about threading issues with Tkinter and am wondering what
aproach to take. Can someone give me some pointers?

rob

From pinard at iro.umontreal.ca  Thu Sep  6 11:39:18 2001
From: pinard at iro.umontreal.ca (=?iso-8859-1?q?Fran=E7ois?= Pinard)
Date: 06 Sep 2001 11:39:18 -0400
Subject: pymacs! :-)
In-Reply-To: <6e0ad3b1.0109060128.6c9adc8@posting.google.com>
References: 
	<6e0ad3b1.0109060128.6c9adc8@posting.google.com>
Message-ID: 

[Brian McErlean]

> Oh dear - oddly enough I'm currently writing exactly the same thing -
> I'd even decided to call it pymacs :-) Rather worryingly, it looks like
> I've even implemented it in a similar way.

That's why it is a good thing to announce what we are working at, if we
know we have any chance to get through, so to trigger collaboration! :-)

> > In LISP, I also gave me some more direct tools:
> > 
> >    (exec-python "PYTHON-STATEMENTS")
> >    (eval-python "PYTHON-EXPRESSION")
> >    (apply-python FUNCTION ARGUMENTS)

> I just have one function, (pymacs-eval "python-statement-or-expression").
> This evaluates either, but returns nil for a statement.  [...]  Actually,
> I think your way having seperate exec and eval may be a better idea -

So far, on my side, I found out that "python-exec" (I moved "python" as a
prefix rather than a suffix) is not really needed in practice.  The most
useful is "python-apply", yet the user almost never use it directly: these
are only used indirectly through the LISP "defun" which get installed in the
LISP space through the action of "python-import".  As for "python-eval",
I found it useful for writing quick tests, but I would not think it very
useful in real applications.

In practice on the LISP side, one does "(python-import MODULE)" and merely
use the imported functions, without paying much attention anymore if they
were written in LISP or Python.  To make thins a bit more transparent,
I'm pondering some "(autoimport ...)"  function to mimick "(autoload ...)",
unless -- this is unlikely -- I find a neat way to overload "(autoload ...)".

> > From the Python side, I may also call Emacs for help:
> >    eval_lisp("LISP-EXPRESSION")

Since then, I changed that to the simpler:

    from pymacs import lisp
    ...
    value = lisp("LISP-EXPRESSION")

In fact, not much besides `lisp' is needed from the `pymacs' module,
and Python functions not needing Emacs services do not even need `lisp'.
The rest is fairly automatic.

> Sometimes doing seemingly simple things can mean a lot of work - eg.
> (funcall (pymacs-eval "map") (pymacs-eval "lambda x:x+1") (1 2 3 4 5))

I paid attention so opaque LISP objects could be made available on the
Python side, and found back automatically when transmitted back to the
LISP side from Python.  You paid attention to the other way, and found
ways to represent non-simple Python objects on the LISP side.  So it seems
we solved complementary problems, and this is enough for me to be quite
interested in your works! :-)

I confess that I did not tackle Python opaque representations in LISP,
because I do not see how to avoid memory leaks.  If one creates a Python
object meant to be returned on the LISP side, one has to keep a reference
active to that object on the Python side, and later copies of corresponding
references could be made on the LISP side.  But then, how do one gets a clue
about when the references on the LISP side still exists or not?  Without
clues, I do not see other choices than keeping the Python object around
forever, and it might not be acceptable in long running Emacs sessions,
where a lot of Python objects could be progressively tied in this way.

On the other hand, I easily forgave myself for not doing so, as I was not
loosing so much.  I aim writing LISP extensions in the Python language,
much more than give a Python flavour to my LISP writings.  After all,
I'd rather write in Python than in LISP whenever I seek a Python flavour.
I think LISP objects like windows, buffers, markers, overlays, etc. should
be fully usable from the Python side, even if this implies a lot of automatic
synchronisation between Emacs and LISP.  I guess I reached that goal.

> > Two things are missing before I'm happy.  First, this is all too
> > fragile to errors: a Python exception should properly be seen on the
> > Emacs side, and vice-versa.

> My error handling is fairly simple really - I have a special character
> I return to python as the response to a call - ">" indicates emacs is
> makeing another call to python, "&" indicates a response to pythons call,
> and "!" indicates an error, after which I just throw a LispError() - which
> will in turn be passed to emacs using an error code.  It would be nice
> to provide some kind of backtrace up both emacs and python calls though.

Currently in my things, the Python backtrace gets displayed in the
mini-buffer (which is resized for the circumstance) *and* the LISP backtrace
is shown in the `*Backtrace*' window.  Together with the `*Pymacs*'
communication window, that makes plenty for debugging.  I made no kind of
effort to transmit the LISP backtrace on the Python side, as I do not see
a purpose for it: all debugging is done within Emacs windows anyway.

If cross-calls between LISP and Python nest deeply, an error will raise
successive exceptions alternatively on both size as things unstack, and
the diagnostic gets transmitted back and forth, slightly growing as we go.
I hope my logic is correct: these things are a bit complex to sort out
and I did not overly tested it yet.

> I have several functions on the emacs class:

> emacs.get_func(name)  - looks up (symbol-function 'name) and returns
> it, or None
> emacs.get_value(name) - just calls emacs.eval(name)
> and __getitem__       - return get_func(name) or get_value(name)

As you might guess, I had to think on similar lines, but was happy to
use `__call__' to sort out if a LISP object is meant as a function or as
a value.  Simplifying my code, I found out that the easiest avenue was to
merely shovel that problem on the LISP side, and I guess I did it cleanly.

> I considered using automatic `_' to `-' and having syntax like
> emacs.add_hook, using `__getattr__' but I didn't like the automatic
> conversion - what do you do for functions that do contain `_'?

The automatic conversion is really useful, it is well worth, so I support
it fully on both sides.  In my current Emacs here, there are only four
symbols having an underscore: `shift_jis', `shift_jis-dos', `shift_jis-mac',
and `shift_jis-unix', and they are only useful for their property lists.
Because "lisp.shift_jis" would really refer to `shift-jis', in such cases,
I would use "lisp['shift_jis']".  Automatic conversion only occurs for
the attribute notation.

> Your implementation does sound very interesting though - maybe we should
> collaborate and take the best of our respective designs?

By all means!  Deep down, these are the goal and result which attract me,
not really imposing my ideas.  A single better tool has more chance growing
roots, than two competing and lesser packages.  You understand that I would
like enjoying some ideas I had, when I dare considering them good ideas! :-)

> Currently, I had planned on releasing my version sometime next week.  
> I don't have the source with me at work, but I'll see about maybe
> posting a preliminary release sometime soon.

Do you prefer that we post our respective versions and let these influence
our respective designs, or that we seek some integrated solution through
private communications, before posting?  Or should we discuss publicly?
It depends a bit on if there are many Emacs users who have practical
interest in writing `.py'/`.pyc' files next to their `.el`/`.elc' files!

-- 
Fran?ois Pinard   http://www.iro.umontreal.ca/~pinard

From jkraska at san.rr.com  Sun Sep  2 14:58:35 2001
From: jkraska at san.rr.com (Courageous)
Date: Sun, 02 Sep 2001 18:58:35 GMT
Subject: Stackless Python and Python 2.x
References:   <3B8EF2E6.CAEB05CC@cosc.canterbury.ac.nz>
Message-ID: 

On Fri, 31 Aug 2001 14:13:58 +1200, Greg Ewing  wrote:

>Michael Abbott wrote:
>> 
>> I've seen Guido van Rossum quoted as being against this because it's
>> incompatible with the Java Virtual Machine (as I understood it).
>
>The other reason is that, by all accounts, if anyone
>other than Christian Tismer tries to do anything with
>the core code, their brain explodes.

I know you were being a bit tongue-in-cheek, however I
would like to point out that the conceptual leap to
understanding that first-class continuations is to
understand that they offer the programmer a direct
instrument by which to create a stack-safe dynamic
goto label which can cross function-definition boundaries.
They're really nothing more than an instrument by which
the programmer can force their own context-switch.

Stacklessness isn't strictly required for this, it's
just considerably more efficient.

C//

From mlh at idi.ntnu.no  Sun Sep  2 21:44:58 2001
From: mlh at idi.ntnu.no (Magnus Lie Hetland)
Date: Mon, 3 Sep 2001 03:44:58 +0200
Subject: Migrating from PHP to Python...
References:  
Message-ID: <9munaq$9up$1@tyfon.itea.ntnu.no>

"Richard Jones"  wrote in message
news:mailman.999474243.26942.python-list at python.org...

> > From what I've read, PHP
> > is faster, less resource intensive, and more prevalent (especially with
web
> > hosts).
>
> So why bother? Really, why are you here at all with this sort of attitude?

That's not very helpful, is it?

(Yes, the rest of your post _was_ very helpful, I'm sure ;)

Basically, AFAIK what he says is fact, not "attitude". But the question is
valid nonetheless, isn't it? I believe the strengths of Python in this case
is its readability, its object-orientedness etc., etc. But even though
Python is what I use for most of my programming, I still use PHP for a
lot of web development, simply because it is almost ubiquitous, and because
it is fast etc. Python doesn't have the same "server page" focus as PHP,
and there is really no reason why it should.

>
>     Richard
>

--

  Magnus Lie Hetland         http://www.hetland.org

 "Reality is that which, when you stop believing in
  it, doesn't go away."           -- Philip K. Dick

From hungjunglu at yahoo.com  Fri Sep 28 10:42:29 2001
From: hungjunglu at yahoo.com (hungjunglu at yahoo.com)
Date: Fri, 28 Sep 2001 14:42:29 -0000
Subject: Fwd:  Re: Problem with os.system()
Message-ID: <9p228l+jhl8@eGroups.com>

--- In python-list at y..., "Terry Reedy"  wrote:
>Perhaps there is a command line option that would tell it to do so.

In the time it takes to type and post your message, you could have 
just visited google and hit the right answer:

mplayer2 /play /close applause.wav

see:

http://support.microsoft.com/support/kb/articles/Q241/4/22.ASP

Hung Jung

From skip at pobox.com  Tue Sep 25 16:22:54 2001
From: skip at pobox.com (Skip Montanaro)
Date: Tue, 25 Sep 2001 15:22:54 -0500
Subject: Why not 3.__class__ ?
In-Reply-To: 
References: <3v9bqtogrl53sfqor0f81oojaa94tr0qt5@4ax.com>
        <9o4amf02357@enews4.newsguy.com>

Message-ID: <15280.59294.607840.917806@beluga.mojam.com>

    >> No, but that wouldn't be the only cause of ambiguity. Consider
    >> "3.e17". This could be either a number in scientific notation, or the
    >> e17 attribute of the 3. literal.

    Marcin> Numbers don't have attributes named with 'e' and digits, so
    Marcin> resolving this ambiguity to scientific notation doesn't cause
    Marcin> trouble to any useful program.

The float type will be subclassable in the future (if not already today in
2.2a3), at which point floating point numbers could indeed have attributes
that begin with the letter 'e' or even an attribute named 'e17'.

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/

From thp at cs.ucr.edu  Mon Sep  3 23:29:43 2001
From: thp at cs.ucr.edu (thp at cs.ucr.edu)
Date: Tue, 4 Sep 2001 03:29:43 +0000 (UTC)
Subject: Conditional operator in Python?
References: <3AC68CB8.22AAF7B8@alcyone.com> <9a631k$3s8qb$1@ID-11957.news.dfncis.de>  <3AC6BB2E.1E09B5AA@alcyone.com> 
Message-ID: <9n1hr7$7op$1@glue.ucr.edu>

Marcin 'Qrczak' Kowalczyk  wrote:
: Sat, 31 Mar 2001 21:22:54 -0800, Erik Max Francis  pisze:

:> The Python FAQ, for instance, suggests x ? a : b can be reliably
:> substituted with
:> 
:>     (x and [a] or [b])[0]

: It computes both a and b. 

No.

: A correct solution is
:     (0 and (lambda: a) or (lambda: b))()

Yes.

: Yes, it is ugly.

Agreed.  Something more aesthetic is definitely needed.  I hate writing:

  factorial = lambda x : (x<=1 and [1] or [x*factorial(x-1)])[0] 

Tom Payne

From porter at et.byu.edu  Tue Sep 11 11:51:55 2001
From: porter at et.byu.edu (C. Porter Bassett)
Date: 11 Sep 2001 08:51:55 -0700
Subject: idea: Robocode for Python
References: 
Message-ID: <84552519.0109110751.6abc9e27@posting.google.com>

> Wouldn't jython fill the bill in this case?  

I had the same thought, and decided to try it.  Since I don't have any
java nor jython experience, I didn't get very far.  I'll post my
progress here in the hopes that somebody can help me get a litte
further.

First of all, here's a very simple .java robot:

  package porter;
  import robocode.*;

  public class CPB extends Robot
  {
    public void run()

      while(true)

        ahead(100);
        turnGunRight(360);
        back(100);
        turnGunRight(360);
      }
    }

    public void onScannedRobot(ScannedRobotEvent e)
    {
      fire(1);
    }
  }

I have no idea what the package porter; line is for, so I ignored it. 
I
added the robocode.jar to my classpath, and tried to translate this
java
code to python.  Here's my python file:

  from robocode import *
  class pyrobot(Robot):
     def run(self):
        while(1):
           ahead(100)
           turnGunRight(360)
           back(100)
           turnGunRight(360)
     def onScannedRobot(self, event):
        fire(1)

I ran that through jythonc, and it compiled, but I got a depracation
warning.  I recompiled with -deprecation, and here's the output from
jythonc:

  0932:PWORK://d/robocode/robots/porter$ jythonc pyrobot.py
  processing pyrobot

  Required packages:
    robocode.dialog
    robocode.jdk13bugfix
    robocode.editor
    robocode*

  Creating adapters:

  Creating .java files:
    pyrobot module
      pyrobot extends robocode.Robot

  Compiling .java to .class...
  Compiling with args: ['c://jdk1.3.1_01/bin/javac.exe',
'-deprecation',
'-classpath', 'C:\\jython-2.0\\jython.jar;.;C:\\Program
Files\\proe2000i2\\modchk\\java\\xml\\xml4j.jar;c:\\jython-2.0\\jython.jar;d
:\\robocode\\robocode.jar;.\\jpywork;;C:\\jython-2.0\\Tools\\jythonc;d:\\rob
ocode\\robots\\porter\\.;C:\\jython-2.0\\Lib;c:\\jython\\lib;C:\\jython-2.0'
, '.\\jpywork\\pyrobot.java']
  0  .\jpywork\pyrobot.java:100: warning:
jfindattr(org.python.core.PyProxy,java.lang.String) in
org.python.core.Py
has been deprecated
          PyObject inst = Py.jfindattr(this, "onScannedRobot");
                            ^
  .\jpywork\pyrobot.java:110: warning:
jfindattr(org.python.core.PyProxy,java.lang.String) in
org.python.core.Py
has been deprecated
          PyObject inst = Py.jfindattr(this, "run");
                            ^
  2 warnings

When I try to run a robocode battle with this robot, the robocode
console
gives me the following error:

  java.lang.NoClassDefFoundError: porter/jpywork/pyrobot (wrong name:
pyrobot)
          at java.lang.ClassLoader.defineClass0(Native Method)
          at java.lang.ClassLoader.defineClass(Unknown Source)
          at java.lang.ClassLoader.defineClass(Unknown Source)
          at
robocode.JBotsClassLoader.loadRobotClass(JBotsClassLoader.java:55)
          at robocode.Battle.initialize(Battle.java:350)
          at robocode.Battle.run(Battle.java:42)
          at java.lang.Thread.run(Unknown Source)

Because of my utter lack of java knowledge, I am completely stuck.  Is
it
even possible to do what I am trying to do?  If so, what should I try
next?

From robin at jessikat.fsnet.co.uk  Fri Sep  7 14:44:15 2001
From: robin at jessikat.fsnet.co.uk (Robin Becker)
Date: Fri, 7 Sep 2001 19:44:15 +0100
Subject: PyArg_ParseTuple O format semantics
Message-ID: 

Steve Alexander kindly forwarded me a note relating to a change in
getargs.c that occurred between  2.0 and 2.0.1. Basically it was implied
that O format conversion was buggy before in term of the refcount of the
returned object.

The documentation doesn't mention any increment so it seems to return a
borrowed ref.

I'm using the O flag a bit and would like to know if I should be
patching to cover the change -->2.0.1?
-- 
Robin Becker

From ignacio at openservices.net  Thu Sep  6 12:39:07 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Thu, 6 Sep 2001 12:39:07 -0400 (EDT)
Subject: Help getting python/Apache working together on windows
In-Reply-To: 
Message-ID: 

On Thu, 6 Sep 2001, Ignacio Vazquez-Abrams wrote:

> On 6 Sep 2001, Brian Sweeting wrote:
>
> > I have two questions...
> >
> > 1) Is there any way I can run it the same way as php without messing
> > with the httpd.conf file all the time?  I have seen quite a few
> > tutorials on running python as a cgi, but I would like to be able to
> > go to a url and run that script.
>
> AddHandler cgi-script py pyc pyo

D'oh. I forgot putting index.py, index.pyc, and index.pyo in DirectoryIndex.

-- 
Ignacio Vazquez-Abrams  

From chrishbarker at home.net  Mon Sep 24 14:44:25 2001
From: chrishbarker at home.net (Chris Barker)
Date: Mon, 24 Sep 2001 11:44:25 -0700
Subject: To re or not to re ... ( word wrap function?)
References: 
Message-ID: <3BAF7F09.767225B6@home.net>

Thanks to all of you who posted code: I've learned something from each
one.

I did notice that no one used an re-based solution, except Skip using

re.split(r'\s+', s)

Is this any different than string.split(s) ?

Note that I didn't want to use either of these, as they would kill any
sequences of whitespace, such as two spaces after a sentence.

tex_wrap looks very nice but is really overkill for this application.

I also noticed that no one took my approach, which was to start at the
end of the line and work backwards looking for space. You all took the
approach of building the new line word by word from the beginning.

hmmmm.

-Chris

-- 
Christopher Barker,
Ph.D.                                                           
ChrisHBarker at home.net                 ---           ---           ---
http://members.home.net/barkerlohmann ---@@       -----@@       -----@@
                                   ------@@@     ------@@@     ------@@@
Oil Spill Modeling                ------   @    ------   @   ------   @
Water Resources Engineering       -------      ---------     --------    
Coastal and Fluvial Hydrodynamics --------------------------------------
------------------------------------------------------------------------

From tjreedy at home.com  Sun Sep  9 16:08:21 2001
From: tjreedy at home.com (Terry Reedy)
Date: Sun, 09 Sep 2001 20:08:21 GMT
Subject: Proposed PEP for a Conditional Expression
References: 
Message-ID: 

"Michael Chermside"  wrote in message
news:mailman.1000046772.19777.python-list at python.org...
> Included in this email is a PEP which I am putting together dealing
with
> the idea of introducing a conditional expression into Python. I
would
> welcome any discussion, suggestions, and/or help, sent either to
this
> newsgroup under this topic, or emailed to me at .

I'll do both

> PEP, I find ARG_1, ARG_3, and ARG_23 unconvincing, while ARG_21,
ARG_22,
> and ARG_3 all make sense to me

Do you really find ARG_3 both unconvincing and sensible> or is there a
typo?

I suggest relabeling arguments A1, A2, ... (anti) and P1, P2,
...(pro).

> ------------------- DRAFT PEP
FOLLOWS ----------------------------------
> PEP: NO-NUM-YET
> Title: Creating a Short-Circuiting Conditional Expression
...
>      ARG_1: Workarounds exist.

It's really hard to fairly present arguments you find 'unconvincing',
so I will help you.
(Please note: I am impressed at how well you did do, especially for
version 1.)
I'm going to split this into two anti arguments, A1 and A2, and one
pro argument, P1.

A1: Python has conditional statements for conditional assignments.
>              > if c:
>              >     x = a
>              > else:
>              >     x = b
>              Of course, many people would say that just writing it
out
>              is probably the best solution. It can be done in 4
line,
>              or in 2, like this:
>              > if c: x = a
>              > else: x = b

P1.            In either case, though, this is NOT an expression, so
>              using it may require creating a temporary variable and
>              splitting a formula into two lines, or replacing a
lambda
>              expression with a named function.

A2: Python already has short-circuiting conditional expressions (even
if some proponents of an alternative syntax refuse to recognize them
as such by dismissing them as 'workarounds').

         First, the conditional expression that DOESN'T short-circuit:
         > def cond(c, a, b):
         >     if c: return a
         >    else: return b
         > x = cond(c, a, b)
         This fails to short-circuit because arguments to a function
are always
         evaluated before the function is invoked. Thus, for instance,
the
         following would not work properly when a == 0:
         > x = cond( a==0, DEFAULT_VAL, 100/a )

        Next, the expression that ALMOST ALWAYS short-circuits
correctly:
        > x = c and a or b # or, almost equivalently
        > x = (not c) and b or a
        The advantage of this simple form is that it syntactically
matches
        the conditional expression of C with (and,or) substituted for
(?,:).
        Because the boolean operators 'and' and 'or' short circuit,
this idiom
        works whenever a (or b) is certain to evaluate as true for all
values
        of the variables.  This is true of most (all?) realistic
examples given
        by proponents of a new syntax.  Examples:
        > inverses = map( lambda x: x==0 and "Inf" or 1.0/x, values )
        > tags = [ (s is not None and '<%s>' % s or None) for s in
keys ]

        If it is possible that both a and b can evaluate to 'false',
there are clumsier
        but GUARENTEED-TO-WORK forms:
        > x = (c and [a] or [b])[0]
        > x = (c and (a,) or (b,))[0]
        These index into one-element sequences which are definitely
not false.
        The tuple version is slightly faster but more awkward to type
and read.
        > x = (c and (lambda:a) or (lambda:b))()
        Functions are also never false.  The version takes longer to
type
        and may be less readable, especiaoly within an outer lambda.

        In short, this PEP only proposes a new syntax and not a new
funtionality,
        and the argument for the new syntax must adress why such is
worth the
        accompanying costs.
..
>      ARG_21: Simplifies lambda expressions.
...
>      ARG_22: Makes a functional style easier.
...
>       ARG_24: Clarifies intent when used for assignments.

All of these are arguments for the use of expressions rather than
statements.  They all apply equally well to the existing expression
forms. They are not, in themselves, arguments for a new form.

>      ARG_23: Lots of people ask for it.
>          Lots of people ask for a conditional expression.

Some are ignorant of the current forms, some deny that they are what
they are, and some want something we do not currently have (a simple
form without cruft, like C's, that always works) but have not settled
on anything specific for the rest of us to consider.  I hope this
'PEP' helps all three groups.

Terry J. Reedy

From phil.harris at zope.co.uk  Wed Sep 12 07:49:37 2001
From: phil.harris at zope.co.uk (Phil Harris)
Date: 12 Sep 2001 04:49:37 -0700
Subject: Python with threads for Cygwin.
Message-ID: 

All,

Has anyone ever managed to create a version of Python with threads on Cygwin?

If so, what is the secret incantation?

Phil

From root at rainerdeyke.com  Wed Sep  5 15:15:57 2001
From: root at rainerdeyke.com (Rainer Deyke)
Date: Wed, 05 Sep 2001 19:15:57 GMT
Subject: no parallel threading?
References: 
Message-ID: 

> On Wed, 5 Sep 2001, Tobias Unruh wrote:
>
> >Hi,
> >
> >I tried to execute two threads in parallel (linux 2.4.9, python 2.0):
> >
> >import time
> >import threading
> >
> >def test_thread_func1():
> >    print "Hallo1"
> >    time.sleep(3.0)
> >    print "Hallo1"
> >
> >def test_thread_func2():
> >    print "Hallo2"
> >    time.sleep(3.0)
> >    print "Hallo2"
> >
> >printlock = threading.Lock()
> >
> >test_thread1 = threading.Thread(None,test_thread_func1())
> >test_thread2 = threading.Thread(None,test_thread_func2())
                                                         ^^

You are calling 'test_thread_func1', and passing the result to
'threading.Thread'.  In other words, your function has already terminated
before the thread object is created.  Try leaving off the '()' after
'test_thread_func1' and 'test_thread_func2'.

--
Rainer Deyke (root at rainerdeyke.com)
Shareware computer games           -           http://rainerdeyke.com
"In ihren Reihen zu stehen heisst unter Feinden zu kaempfen" - Abigor

From tjreedy at home.com  Tue Sep 18 11:51:43 2001
From: tjreedy at home.com (Terry Reedy)
Date: Tue, 18 Sep 2001 15:51:43 GMT
Subject: Request for example of state machine using generators
References: 
Message-ID: 

"Tim Peters"  wrote in message
news:mailman.1000792880.26234.python-list at python.org...
> In 2.2a3 (or CVS), you can look at Tools/scripts/cleanfuture.py for
an
> extended example of using generators to avoid state machines, there
in a
> parsing context.  Lib/test/test_generators.py also has many examples
of
> generator techniques.

One can view both of these files directly from CVS source with browser
by starting at

http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/python/python/dist/src/

Terry J. Reedy

From qrczak at knm.org.pl  Wed Sep 12 10:16:50 2001
From: qrczak at knm.org.pl (Marcin 'Qrczak' Kowalczyk)
Date: 12 Sep 2001 14:16:50 GMT
Subject: Proposed PEP for a Conditional Expression
References:  <6qvgire4bk.fsf@abnoba.intevation.de> <9nidrm01j7q@enews1.newsguy.com> <9nk4t8$4qq$1@glue.ucr.edu> <9nkmjj01rha@enews3.newsguy.com> <9nnf0d$5qf$2@glue.ucr.edu> <9nnigp02g7a@enews1.newsguy.com>
Message-ID: 

Wed, 12 Sep 2001 13:56:09 +0200, Alex Martelli  pisze:

> I think the proposed conditional operator would be just about at
> the threshold (I wouldn't particularly care either way if it got in
> or stayed out) EXCEPT for the risk that it may in fact encourage
> people to write more lambda's rather than named local functions,
> which I see as a substantial minus.

If we prefer list comprehensions to for loops with appends,
in this case it encourages in the right direction.

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZAST?PCZA
QRCZAK

From gh_pythonlist at gmx.de  Sun Sep 30 01:49:28 2001
From: gh_pythonlist at gmx.de (Gerhard =?iso-8859-1?Q?H=E4ring?=)
Date: Sun, 30 Sep 2001 07:49:28 +0200
Subject: [Q] PyGreSQL
In-Reply-To: ; from shwang5@students.uiuc.edu on Sat, Sep 29, 2001 at 09:24:58PM -0700
References: 
Message-ID: <20010930074925.A1967@lilith.hqd-internal>

On Sat, Sep 29, 2001 at 09:24:58PM -0700, Seung-won Hwang wrote:
> Hi,
> 
> I have two questions on PyGreSQL:
> 
> (1) Could you let me know where the windows version of PyGreSQL is? I failed
> in finding one from web search.

On my homepage you can find one (see sig). I'd recommend you use my
Windows port of pyPgSQL instead, though. The win32 version is now
available from the official homepage
(http://www.sourceforge.net/projects/pypgsql/) and  I'm also a developer
in this project, so think of this as the officially supported one :-))

> (2) What's the easiest way to load tab-separated text data to the relational
> database? Any easier way than writing a program that calls "INSERT INTO" for
> every data value?

AFAIK, all the easy ways involve proprietary tools. Below I've put a
draft of a function that might do what you want. It's not perfect, and I
don't know how to handle things like auto-increment columns.

Gerhard

#############################################################################
#!/usr/bin/env python
import PgSQL

def importTable(cursor, tablename, filename):
    """Imports data from filename into the table tablename. Each line in the
    data file is one record. The fields are tab-seperated."""
    # Build a list of lists; the inner list contains the columns to be inserted
    f = open(filename, "r")
    entries = []
    for line in f.readlines():
	if line.strip() != "":
	    entries.append(line.strip().split("\t"))
    f.close()
    numcolumns = len(entries[0])
    # Build the SQL statement; using %s for any column type is pyPgSQL specific
    sql = "insert into %s values " % tablename
    sql += "(" + ", ".join(["%s"] * numcolumns) + ")"
    cursor.executemany(sql, entries)

db = PgSQL.connect()
cursor = db.cursor()
importTable(cursor, "test", "testdata.txt")
db.commit()
-- 
mail:   gerhard  bigfoot  de       registered Linux user #64239
web:    http://www.cs.fhm.edu/~ifw00065/    OpenPGP public key id 86AB43C0
public key fingerprint: DEC1 1D02 5743 1159 CD20  A4B6 7B22 6575 86AB 43C0
reduce(lambda x,y:x+y,map(lambda x:chr(ord(x)^42),tuple('zS^BED\nX_FOY\x0b')))

From mmhamze at pleiades.net  Fri Sep  7 09:04:47 2001
From: mmhamze at pleiades.net (Maan M. Hamze)
Date: Fri, 7 Sep 2001 08:04:47 -0500
Subject: Creating Excel files on Linux
References: <3B97A39C.6A5234D7@olen.to> 
Message-ID: 

But the question is:  Can Staroffice create XLS files?  If not, then it is a
major waste of time to create spreadsheets using Staroffice.  It is a world
that speaks the XLS language.
Maan

"Carlos Gaston Alvarez"  wrote in message
news:mailman.999798189.20175.python-list at python.org...
> Staroffice can run java programs the same way Office can run Visual Basic.
> If you dont know java it may be easier for you to jython (python in java).
> Staroffice (for the moment) is free.
>
> Why dont you take a look? If it works please mail me. I have never used it
> that way. Neither I know where the jdk is.
>
> Chau,
>
> Gaston
>
>
> ----- Original Message -----
> From: "Joonas Paalasmaa" 
> Newsgroups: comp.lang.python
> To: 
> Sent: Thursday, September 06, 2001 6:26 PM
> Subject: Creating Excel files on Linux
>
>
> > Is there any way to create xls or some other format that
> > MS Excel can read excluding CSV.
> > I am using Linux so I think that COM is not an option.
> >
> > --
> > Joonas
> > --
> > http://mail.python.org/mailman/listinfo/python-list
> >
>
>

From rdsteph at earthlink.net  Sun Sep  9 12:50:41 2001
From: rdsteph at earthlink.net (Ron Stephens)
Date: Sun, 09 Sep 2001 16:50:41 GMT
Subject: Python and Zope
References:  
Message-ID: <3B9B9F92.DF67BC9@earthlink.net>

Three points:

1. Python will work with .NET (see ActiveState's web site for Visual Python .NET
beta. So, any work you do now in Python will not be lost if you later convert to
the .NET runtime, in fact, Python will offer a fully compatible, more productive
development environment for .NET than any other language.

2. .NET is simply not ready *yet*, so I suspect it would be a little hard to do
your work right now in .NET. I agree with you that .NET looks promising and is
well thought out, but it is very early in the day to be committing a major
project to .NET, especially when the Python option is so inviting, both now
(fully mature development environment) and in the future (fully compatible .NET
language).

3. Zope works, is more powerful than any other option available at this time,
and because its written in Python, has a great future.

Cheers,

Ron Stephens

Ken Egervari wrote:

> I'm actually very used to the PHP interpreter as I've done a few large
> websites with it.  It's not powerful enough for my needs and I need to go to
> something with higher performance, scalability, cleanliness and just into a
> better multi-tiered, OO environment.  I know you can hack and do it in PHP -
> I'm looking for a nice framework that works that can help me deploy faster.
>
> Some I'm looking at:
> Java Enterprise (which I have previous experience in)
> .NET (i'm very impressed)
> Python and/or Zope
>
> Java doesn't look that great sinec I have to spend a lot more money on
> servers to get it running at the same performance as Python.  I'm not sure
> of the speeds that .NET provides.  I can't see it being ultra fast since the
> common language layer and the extra-added framework to make development
> easier will no-doubtedly slow it down.  Zope looked very interesting, but
> it's very akward to get used to structuring websites when you have been
> doing large frameworks for a long time in a traditional environment.
>
> Any help appreciated.
> Ken
>
> "Ignacio Vazquez-Abrams"  wrote in message
> news:mailman.1000048100.22478.python-list at python.org...
> > On Sun, 9 Sep 2001, Oleg Broytmann wrote:
> >
> > >    Apache modules are just CGIs. Apache forks off a child at random, and
> at
> > > random kills children. On the other hand, web-application server is
> always
> > > in memory. This allows for the server to create persistence connection
> to a
> > > DB. How can you implement persistence connection in Apache module? Those
> > > "solutions" that are in mod_perl and mod_python are (in my not so humble
> > > opinion) just unstable hacks.
> >
> > Bzzt! Thank you for playing.
> >
> > I can't talk about mod_python or mod_perl, but mod_php's interpreter is
> not
> > CGI; it runs in Apache's memory space. Persistent connections are quite
> easy
> > to create (xxx_pconnect() instead of xxx_connect()).
> >
> > Also, Apache does not fork and kill children at random. A certain minimum
> > number of children are created at startup, more are created up to a
> maximum
> > number if necessary, and once a child has served a certain number of
> > connections, it is killed. This results in maximum stability because any
> > memory problems only have a limited amount of time to live.
> >
> > --
> > Ignacio Vazquez-Abrams  
> >
> >

From cb921 at voice.co.za  Tue Sep 25 16:05:22 2001
From: cb921 at voice.co.za (Campbell)
Date: Tue, 25 Sep 2001 22:05:22 +0200
Subject: Lniker Error
Message-ID: 

Hi,

I've finished up my nice new interface.  I wrote all texts on a Linux
box, using the xxmodule.c from my source .tar.gz for a start.  But it
won't compile on NT, I've pasted the output from VC++ below.

What stupid thing did I forget?

Windows NT 4 plus Microsoft Visual C++ 6.

--------------------Configuration: testmodule - Win32 Debug--------------------
Linking...
testmodule.obj : error LNK2001: unresolved external symbol __imp___Py_Dealloc
testmodule.obj : error LNK2001: unresolved external symbol __imp___Py_RefTotal
testmodule.obj : error LNK2001: unresolved external symbol __chkesp
testmodule.obj : error LNK2001: unresolved external symbol __imp__Py_InitModule4TraceRefs
LINK : error LNK2001: unresolved external symbol __DllMainCRTStartup at 12
Debug/testmodule.dll : fatal error LNK1120: 5 unresolved externals
Error executing link.exe.

testmodule.dll - 6 error(s), 0 warning(s)

Cheers,
Campbell

From warkid at storm.ru  Fri Sep  7 14:55:40 2001
From: warkid at storm.ru ( Kerim Borchaev ( WarKiD ) )
Date: Fri, 7 Sep 2001 22:55:40 +0400
Subject: Customizing module globals
In-Reply-To: 
References: 
Message-ID: <14955.010907@storm.ru>

>> But te problem is that import fails...
>>
>>   File "ModuleUser.py", line 1, in ?
>>     import Module
>>   File "Module.py", line 1, in ?
>>     Object.doThings()
>>   NameError: name 'Object' is not defined
TR> OK, You can't modify a module until it has been imported successfully,
TR> and you cannot run something during import that has not yet been
TR> defined.  So module would have to import Object from somewhere else
TR> before it tries to access Object.

But there _is_ a module that isn't explicitly imported - __builtins__ .
And may be one can specify other names to be present in module's
namespace just before it is executed?

Best regards,
 Kerim                            mailto:warkid at storm.ru

From facelle at jumpy.it  Wed Sep 26 14:12:03 2001
From: facelle at jumpy.it (Fabrizio)
Date: Wed, 26 Sep 2001 20:12:03 +0200
Subject: Py2exe beginner troubles
Message-ID: <9ot7pg$ci1$1@serv1.albacom.net>

Hi,

I am trying to use Py2exe to build a standalone executable of a very basic
program (see below), but with no luck.

This is what I get:

error: invalid command 'py2exe' (no module named 'distutils.command.py2exe')

What am I doing wrong ?

Any help will be appreciated.

Thanks in advance,

Fabrizio

-----------------------------------------------------------------

Here are the details:

I use :

Python 2.0 installed in C:\Python20
Windows98
py2exe-0.2.6.win32-py2.0.exe installed in C:\Python20\py2exe

-------------

This is the program I am trying to "compile" :

def fact (x):
    f=1
    for t in range (1, x+1):
        f=f*t
    print f

z = input("Input a number ")
fact (z)

-----------------

And this is my setup script :

from distutils.core import setup
import py2exe
setup(name="fact",
               scripts=["fact.py"],
         )

----------------

I run it using :

c:\python20\python setup.py py2exe -W

From matt at mondoinfo.com  Mon Sep 24 23:36:52 2001
From: matt at mondoinfo.com (Matthew Dixon Cowles)
Date: Tue, 25 Sep 2001 03:36:52 GMT
Subject: Tkinter and frame resizing question
References: 
Message-ID: 

On Mon, 24 Sep 2001 22:40:13 +0200, Laura Creighton 
wrote:

>When I use grid_remove() to remove a big frame, the window is
>redrawn from the top down, and so my tiny frame moves upwards.
>I don't want this.  I'd prefer to anchor the tiny frame to the
>bottom of the screen and then have the top of the window rise
>or fall depending on how many big frames I grid.  Does anybody
>know how to do this?

Dear Laura,
I don't think you're going to have much luck doing things that way.
At best, I think you'd have a window that bounced around the screen.
The reason for that is that the location of the upper left of your
window is under the window manager's control (you can use the
geometry() method to request that it be moved). I doubt that you'd
have much success in getting your window manager to move the window
down just as you were shortening your window. I'd suggest that you
consider a couple of alternatives:

You could put the frame with the control buttons near the top of your
window.

You could used a fixed-size frame (perhaps one with scroll bars) above
your control buttons and pack or grid your other frames into it. Pmw
has a scrolled-frame:

http://pmw.sourceforge.net/doc/ScrolledFrame.html

You could use a Pmw PanedWidget; it allows you to add and remove sub-widgets
and they can have varying heights:

http://pmw.sourceforge.net/doc/PanedWidget.html

Regards,
Matt

From jinu_lee at hotmail.com  Tue Sep 11 22:36:25 2001
From: jinu_lee at hotmail.com (Jinu Lee)
Date: Wed, 12 Sep 2001 02:36:25 GMT
Subject: "weird" behavior of __file__ attribute
References: <9naf7h$ojk$1@news.urz.uni-heidelberg.de>
Message-ID: 

The result is not related to the way you call mytest.py.
The first time you call it, mytest.py imports mytestA.py and python
interpreter creates compiles mytestA.py into mytestA.pyc.
After that, when you call mytest.py again and it imports mytestA.py, the
interpreter finds mytetsA.pyc and imports that file.

If you delete the mytestA.pyc file and call mytest.py in your second way,
you will get the same result as the first one.

Jinu

"cherzog"  wrote in message
news:9naf7h$ojk$1 at news.urz.uni-heidelberg.de...
> Hello All,
> The __file__ attribute of a module behaves in a way I do not understand:
> I have the following example on Windows with Python 2.1: I got two files
in
> C:\
> first: C:\mytest.py
> second: C:\mytestA.py
>
> mytest.py is:
> #----------start of file------
> import os
> import mytestA
> print "cwd: ", os.getcwd()
> print "mytestA.__file__: ", mytestA.__file__
> #----------end of file
>
> while mytestA.py says simply hello:
>
> #----------start of file------
> print "hello"
> #----------end of file
>
> If I type:
> C:\>mytest.py
> I get:
> Hallo
> cwd:  C:\
> mytestA.__file__:  C:\mytestA.py
>
> But if I type:
> C:\>C:\programme\python21\python mytest.py
> I get:
> Hallo
> cwd:  C:\
> mytestA.__file__:  mytestA.pyc
>
> This is not what I wanted because I hoped to find out the exact path of
> module mytestA.py no matter  how I call mytest.py.
> Please, can someone help me?
> Thank you
> Christoph
>
>

From chris.gonnerman at newcenturycomputers.net  Thu Sep 27 00:29:43 2001
From: chris.gonnerman at newcenturycomputers.net (Chris Gonnerman)
Date: Wed, 26 Sep 2001 23:29:43 -0500
Subject: Using glob (was Re: Remove files of same type (extension))
References: <9on1mq$pj8$04$1@news.t-online.com> <3BAF3754.68BDA949@yahoo.com>  <3BB00766.CC23290C@engcorp.com>  <9ophr4$7u8$1@quark.noos.net>  <9os8qv$d96$1@neon.noos.net> <3BB1DDE2.DD45D2C8@engcorp.com> <9osnri$l9$1@quark.noos.net> <3BB298B9.B266995C@engcorp.com> <9ou8qk$dog$1@neon.noos.net>
Message-ID: <006d01c1470d$11f80b60$0101010a@local>

I too am perplexed as to what ls has to do with the glob module...
what IS the point?  You have adequately pointed out obvious matters
regarding the results of shell globbing and of the output of ls -a;
we can all see that you understand Unix reasonably well.  But what
is the point you are belaboring?

(BTW visited your site, loved it overall).

----- Original Message -----
From: "Boyd Roberts" 
Newsgroups: comp.lang.python
To: 
Sent: Wednesday, September 26, 2001 11:06 PM
Subject: Re: Using glob (was Re: Remove files of same type (extension))

> "Peter Hansen"  a ?crit dans le message news:
3BB298B9.B266995C at engcorp.com...
> > Boyd Roberts wrote:
> > >
> > > "Peter Hansen"  a ?crit dans le message news:
3BB1DDE2.DD45D2C8 at engcorp.com...
> > > > I don't understand the part about it being only "with the complicity
of ls".
> > >
> > > echo *
> > > echo `ls`
> >
> > This is meaningless.  ls returns the non-hidden files.
>
> i see you've used a unix system recently:
>
> $ echo *
> bin dead.letter junk pester.txt s src
> $ echo `ls`
> bin dead.letter junk pester.txt s src
> $ echo .*
> . .. .Xauthority .article .basser .cai .facesrc .forward.mhs
.forward.plan9 .ft
> .history .mail_dir .mailrc .mini .news_time .plan .planete .pnewsexpert
.profile
>  .sh_history .sig .smp.g8-3 .xsession-errors
> $ echo `ls -a`
> . .. .Xauthority .article .basser .cai .facesrc .forward.mhs
.forward.plan9 .ft
> .history .mail_dir .mailrc .mini .news_time .plan .planete .pnewsexpert
.profile
>  .sh_history .sig .smp.g8-3 .xsession-errors bin dead.letter junk
pester.txt s s
> rc
> $
>
> how much more chapter and verse would you like?
>
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>

From richard at bizarsoftware.com.au  Thu Sep 27 04:02:27 2001
From: richard at bizarsoftware.com.au (Richard Jones)
Date: Thu, 27 Sep 2001 18:02:27 +1000
Subject: Does there exist a Python-to-Perl translator ?
In-Reply-To: <3BB2D226.3C260A2C@Spam.Please>
References: <3BB2D226.3C260A2C@Spam.Please>
Message-ID: <0109271802270U.13278@ike>

On Thursday 27 September 2001 17:15, Weet Vanniks wrote:
> This would help me produce Perl code after developing it in Python.

OK, I'll bite - WHY?

As far as I know, no such beast exists.

    Richard

From markus at schabi.de  Fri Sep 14 06:05:26 2001
From: markus at schabi.de (Markus Schaber)
Date: Fri, 14 Sep 2001 12:05:26 +0200
Subject: Newbie:  Why Does This Work This Way...Global Variables And The Signal Module....
References: <2bao7.472498$ai2.35646143@bin2.nnrp.aus1.giganews.com>
Message-ID: <1389985.cojqenx9y0@lunix.schabi.de>

Hi,

John Branthoover  schrub:

>     I have written a simple program to break out of a endless loop by
> hitting control C,  see below.  This program works OK but I don't
> understand why I have to define the global variable "Loop_Run" twice
> to get it to work. I thought that you had only to define a global
> variable once at the beginning of a program and that made it available
> to rest of the module.

The global statement is no definition in this way. All variables are 
usually from their local scope, so if you do

def f():
        loop_run=0

then this sets the variable local to the current function. The global 
statement just tells the byte-code compiler to use the global variable 
loop_run during the current function whenever anything accesses 
loop_run. Imagine this as some kind of "search redirection" which says 
"don't use local scope, but global scope for this name".

So you have to tell this in every function and method you need it.

Also remember that the variable is created on the first write access to 
it. A "definition" - as known from static languages - is not knowt to 
python.

Another point is that the python interpreter allows omitting the global 
statement whenever the variable is only read and not written in the 
function - because in this case, there can't be a local variable.

So you could rewrite your example as follows:

#!/usr/local/bin/python
import signal

def signal_handler(signal, frame):
    global Loop_Run
    Loop_Run=0
    print 'Signal Handler',Loop_Run

def Main():
    while Loop_Run<>0:
        print 'Loop is running because Loop_Run = ',Loop_Run
    print  'Loop is stopped because Loop_Run = ',Loop_Run

Loop_Run=1
signal.signal(signal.SIGINT, signal_handler)

if __name__=='__main__':
    Main()

markus
-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From jriveramerla at yahoo.com  Sat Sep 15 03:13:58 2001
From: jriveramerla at yahoo.com (Jose Rivera)
Date: 15 Sep 2001 00:13:58 -0700
Subject: Thanks for the help...
Message-ID: <11e94203.0109142313.759a300b@posting.google.com>

Thanks... the problem was that I was using wxPython 2.3.1

When I changed to wxPython 2.2.5 BOA worked ok and I finished the
Getting Started Tutorial witout any problem.

thanks...

From peter at engcorp.com  Wed Sep 26 23:10:49 2001
From: peter at engcorp.com (Peter Hansen)
Date: Wed, 26 Sep 2001 23:10:49 -0400
Subject: Using glob (was Re: Remove files of same type (extension))
References: <9on1mq$pj8$04$1@news.t-online.com> <3BAF3754.68BDA949@yahoo.com>  <3BB00766.CC23290C@engcorp.com>  <9ophr4$7u8$1@quark.noos.net>  <9os8qv$d96$1@neon.noos.net> <3BB1DDE2.DD45D2C8@engcorp.com> <9osnri$l9$1@quark.noos.net>
Message-ID: <3BB298B9.B266995C@engcorp.com>

Boyd Roberts wrote:
> 
> "Peter Hansen"  a ?crit dans le message news: 3BB1DDE2.DD45D2C8 at engcorp.com...
> > I don't understand the part about it being only "with the complicity of ls".
> 
> echo *
> echo `ls`

This is meaningless.  ls returns the non-hidden files.  Echoing them
is no different than just displaying the names.  What do you expect
to see from echo `ls` that you don't see from just ls ?

Anyway, what the hell is your point?  You aren't even arguing a point
here, just posting snippets of apparently (to me... please enlighten me)
useless and meaningless shell code without even attempting to explain
why you think it's relevant.

Again another way: ls is just a command, one of many.  You don't
need to use it or even have it on your system, and yet the shell
still goes ahead doing globbing (e.g. echo *) and following the
rules of shell globbing referred to in the first place.  Just what
this has to do with ls and its supposed complicity in the matter
is really beyond me.

(Please reply with English rather than shell script if you have 
a point to make.)

(Apologies for sounding curt, but this is the third message from
you on the topic which doesn't seem to catch the point.  Maybe 
I'm just missing something that's obvious to you.)

-- 
----------------------
Peter Hansen, P.Eng.
peter at engcorp.com

From fdrake at acm.org  Thu Sep  6 15:34:38 2001
From: fdrake at acm.org (Fred L. Drake)
Date: Thu,  6 Sep 2001 15:34:38 -0400 (EDT)
Subject: [development doc updates]
Message-ID: <20010906193438.C242828845@cj42289-a.reston1.va.home.com>

The development version of the documentation has been updated:

    http://python.sourceforge.net/devel-docs/

Documentation for 2.2 alpha 3.

From mlh at idi.ntnu.no  Mon Sep  3 16:11:20 2001
From: mlh at idi.ntnu.no (Magnus Lie Hetland)
Date: Mon, 3 Sep 2001 22:11:20 +0200
Subject: Can I build a dictonary with a list-comprehension?
References: 
Message-ID: <9n0o58$d1a$1@tyfon.itea.ntnu.no>

"Hans Nowak"  wrote in message
news:mailman.999504963.22471.python-list at python.org...

> Un an entirely unrelated note, maybe there should be dictionary
> comprehensions, too... :)
>
> { k,v for k,v in dict if type(v) == type("") }
>
> 

I suggested this quite a while ago, but it didn't catch on.

--

  Magnus Lie Hetland         http://www.hetland.org

 "Reality is that which, when you stop believing in
  it, doesn't go away."           -- Philip K. Dick

From cable40 at hotmail.com  Fri Sep 14 18:48:30 2001
From: cable40 at hotmail.com (Cable)
Date: Fri, 14 Sep 2001 22:48:30 GMT
Subject: Newbie Question..  What is the replacement for the ELSE command?.
References:  
Message-ID: <3g15qt4nc8jfg1tcobo2j97ite4pvsthsu@4ax.com>

Thanks for the reply.

The question you asked me, put me on the right track.  I used your
example. after the second line when I hit return, It starts my 3rd
line, directly under the second.  I did a dedent region and it worked.

It will take me a while......  its fun though....

thanks for the help.

On Fri, 14 Sep 2001 22:14:41 GMT, "Maan Hamze" 
wrote:

>Cable
>Can you give an exact example of Python code with 'else' that is not
>working?  Please include all indentations with the code you are using.
>something that works, say for example:
>
>if x==1:
>  print 'happy'
>else:
>  print 'sad'
>
>Maan
>
>"Cable"  wrote in message
>news:qiv4qtkbhi5tgeb2knf14m4r5ikh9jesf1 at 4ax.com...
>> I am trying to teach myself Python.  All the online tutorials, have
>> examples with the else command.  I cant get it to work is there a
>> replacement?
>>
>> Thanks.
>

From ignacio at openservices.net  Fri Sep 14 09:57:18 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Fri, 14 Sep 2001 09:57:18 -0400 (EDT)
Subject: evaluate a variable
In-Reply-To: <9nt218+i3lv@eGroups.com>
Message-ID: 

On Fri, 14 Sep 2001 dimitry_snezhkov at yahoo.com wrote:

> I just started learning Python. Of, course , reading  output of
> __doc__
> is very pleasant. I decided to output documentation for every def in
> a module. How do I evaluate a variable that is dynamicaly generated.
> Sort of hello.$bye.see_ya in Perl :
>
> Here's my code :
>
>     import sys
>
>     for each in range(len(dir(sys))):
>         method='sys' + '.' + dir(sys)[each] + '.' + '__doc__'
>         ## i cannot do
>         print method.__doc__
>         ## this doesn't evaluate method properly.
>         ## Does eval work in this situation?
>
> Also, please, let me know if what I am trying to do is awkward way of
> doing it. How does Python approach such evaluation.

import sys

for each in dir(sys):
  try:
    print '%s: %s' % (each, getattr(sys, each).__doc__)
    print
  except AttributeError:
    print

-- 
Ignacio Vazquez-Abrams  

From aleax at aleax.it  Mon Sep  3 06:11:07 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 3 Sep 2001 12:11:07 +0200
Subject: COM/CORBA/DCOP (was: Hello people. I have some questions)
References:  <9mu5si$9gg$1@pea.uk.research.att.com>
Message-ID: <9mvkvr01db@enews2.newsguy.com>

"Duncan Grisby"  wrote in message
news:9mu5si$9gg$1 at pea.uk.research.att.com...
    ...
> I don't know why people would consider CORBA too heavyweight for
> connecting desktop apps -- the few performance comparisons between COM
> and CORBA I have seen show CORBA to be as fast or faster than COM.

For *in-process* interaction?!  There's something askew here... I
did the measurements myself back around 1994/1995, under Windows/NT,
using COM (in-process and out-of-process) and Iona's Orbix, which
Iona claimed was the fastest ORB for NT, and the difference in
terms of performance overhead was *at least* an order of magnitude
in favour of COM (using C to program "toy"-level servers and
clients, instrumented for measuring communication overhead, and
striving to simulate the kinds of loads our own applications would
place on a componentization infrastructure).  Have things changed
so drastically since then?

Now, depending on the kind of interoperation those "desktop apps"
do in fact use, a slow-down by a factor of 10 or 20 in the
communication overhead itself may be irrelevant (or else you
wouldn't see any *Automation* usage on top of COM -- the mostly
interpretive nature of Automation dispatching does impose at
least that much extra overhead when compared to down-to-the-
metal COM on binary interfaces).  But "Corba faster than COM"
(except any _remoting_ scenario -- I'm *NOT* saying DCOM is a
match for IIOP, mind you!-) is really news to me.

Alex

From timr at probo.com  Thu Sep  6 00:42:16 2001
From: timr at probo.com (Tim Roberts)
Date: Wed, 05 Sep 2001 21:42:16 -0700
Subject: Question regarding commenting code
References: <682EFA0F37A1D511868700B0D0D1AB7A31BBDD@ISTECH4> 
Message-ID: 

Roman Suzi  wrote:

>On Tue, 4 Sep 2001, Andrew Gould wrote:
>
>>When adding comments to scripts, can I insert lines of comments inside a
>>loop block?  For example:
>>
>>for n in a_list:
>># separate values using spaces as delimiters
>>	a_line = string.split(n)
>># get the first value
>>	a_value = a_line[0]
>># print the first value
>>	print a_value
>
>This is not good.

However, without judging the moral implications, this IS legal.  I assume
that was the purpose of the question.
--
- Tim Roberts, timr at probo.com
  Providenza & Boekelheide, Inc.

From fredrik at pythonware.com  Sun Sep  9 20:01:26 2001
From: fredrik at pythonware.com (Fredrik Lundh)
Date: Mon, 10 Sep 2001 00:01:26 GMT
Subject: os.stat() ?
References: 
Message-ID: 

"Agent Drek" wrote:
> $ touch myfile
> $ ls -l myfile
> -rw-r--r--  1 drek  pow  0 Sep  9 17:07 myfile
>
> import os, stat
> print os.stat('myfile')[stat.ST_MODE] & 0777
>
> I get '420' from os.stat

>>> oct(420)
'0644'

From andy_todd at spam.free.yahoo.com  Tue Sep  4 08:32:04 2001
From: andy_todd at spam.free.yahoo.com (Andy Todd)
Date: 4 Sep 2001 12:32:04 GMT
Subject: newbie question - executing system commands
References: <9n23h1$qsc$1@news.formus.pl>
Message-ID: 

"Borzoj"  wrote in
<9n23h1$qsc$1 at news.formus.pl>: 

>I'm newbie both in shell scripting and pyhon so please be kind :)
>What would be the Python equivalent for following shell code:
>
>for IMAGE_NAME in `ls`; do {
>#processing of $IMAGE_NAME
>};done
>
>
>...or in other words what is the easiest way to execute shell
>command/external program from python and
>get access to it's output?
>
>thx
>____________
>This will be your new motto: dance like it hurts, love like you need
>money, work when pepole are watching.
>Dogbert
>
>

Look at the documentation for the module 'os' - 
http://www.python.org/doc/current/lib/module-os.html

To convert your example above into Python, try;

>>> for imageName in os.listdir('.'):
...     print imageName

at the interactive prompt and see what you get.

-- 
Content free posts a speciality

From thomas.heller at ion-tof.com  Thu Sep 27 07:38:14 2001
From: thomas.heller at ion-tof.com (Thomas Heller)
Date: Thu, 27 Sep 2001 13:38:14 +0200
Subject: Class mutation
References: <8626rt838oe59d1njrtrisccm0oe02shvf@4ax.com>
Message-ID: <9ov336$fpp6v$1@ID-59885.news.dfncis.de>

"Dale Strickland-Clark"  wrote in message news:8626rt838oe59d1njrtrisccm0oe02shvf at 4ax.com...
> Lets say we have a class 'Job' and another class derived from that
> 'ActiveJob'.
>
> I'd like to mutate a Job object into the extended ActiveJob object
> without re-assigning all the attributes.
>
class Job:
    def work(self):
        print "I'm inactive"

class ActiveJob(Job):
    def work(self):
        print "Ok, later"

job = Job()

print job
job.work()

job.__class__ = ActiveJob

print job
job.work()

prints:

<__main__.Job instance at 007B5EBC>
I'm inactive

<__main__.ActiveJob instance at 007B5EBC>
Ok, later

Thomas

From aleax at aleax.it  Mon Sep  3 11:24:35 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 3 Sep 2001 17:24:35 +0200
Subject: typechecks: just say no! (was Re: Determining Types)
References:         <9mvo0u04o8@enews2.newsguy.com>        <3b938f31.2123170@nntp.sprynet.com> 
Message-ID: <9n07bi01ptd@enews1.newsguy.com>

"Skip Montanaro"  wrote in message
news:mailman.999528483.6865.python-list at python.org...
>
> One place that I've actually found typechecking useful is at the boundary
of
> my XML-RPC server.  If I'm expecting a string input (say, the name of a
> band) and someone on the other side inputs "311" to a Perl-based website
> which then passes the query to my server, I get an integer that I have to
> coerce back to a string.  In my comments I call it a "Perl guard". ;-)

So why not just use str(whateverthingyyouget) [or the Unicode
equivalent if Unicode is what you need]?  Beats going around
with "if type..." (or even "if isinstance..."), IMHO.

[BTW, you'll probably be out of luck if somebody needs a
band called "0800" -- you'll get some octalized thing, yes?-)]

Alex

From claysjunkmail at yahoo.com  Sat Sep  1 20:50:58 2001
From: claysjunkmail at yahoo.com (Clayton Brown - Emmie Osawa)
Date: 1 Sep 2001 17:50:58 -0700
Subject: String Comparisons returning score
Message-ID: <1b9aff84.0109011650.76116213@posting.google.com>

Is there an approved standard library/function/algarithm for comparing
two similar strings and returning a percentage match?

I am aware of soundEx.py / .c  which is based on the grammar and
phonetics of words, but from what I have read it seems to be flawed..
and thus removed from the python standard library.

I have noticed similar techniques in other languages which are based
on shift matrixes, working out the minimum number of changes to
transform string A into string B.

I am more looking for one which looks at 
words/
chars/
char-order/
length/
similarity
perhaps omitting spaces, and a common library (the,a,and,mr,mrs......)
with a weighted scoring mechanism...

Thanks in advance...
Clayton Brown / Emmie Osawa

From ralph at inputplus.demon.co.uk  Thu Sep 27 16:29:52 2001
From: ralph at inputplus.demon.co.uk (Ralph Corderoy)
Date: 27 Sep 2001 21:29:52 +0100
Subject: bsddb3 vs zodb
References: <3BA9A72A.1D5A6067@yahoo.com> <9opu3g$8cr$1@inputplus.demon.co.uk> <20010927020213.A18855@zot.electricrain.com> 
Message-ID: <9p0280$plh$1@inputplus.demon.co.uk>

Hi Skip,

> > True.  It's worth noting however that BerkeleyDB 3.3 adds support
> > for automated "secondary indexing" which really gives it a
> > significant chunk of capabilities that people often end up using
> > for full fledged relational databases for. 
>
> Can you explain what "secondary indexing" is?  I was never aware I
> needed it and am using relational databases because of it. ;-)

Have any of your tables got an index built on any column, or
combination of columns, other than the primary key?

For example, given (user_id, surname) then user_id would be the unique
primary key.  No two people would have the same user_id.  Your
relational database can give you a list of all people called `Smith'
but it would have to do this by sequentially stepping through each row
examining the row's surname.

If `surname' is made a secondary key then the database will also
maintain an index of the surnames and you'd have told it they aren't
unique;  there may be more than one Smith in the world.  Then when you
ask for all the Smiths it can use the index for the surname secondary
key to give you the answer much more efficiently.

    user_id surname
    5       Smith
    1       Able
    3       Baker
    2       Charlie
    4       Smith

    surname user_ids
    Smith   5, 4
    Able    1
    Charlie 2
    Baker   3

Ralph.

From ivo at nospamAmaze.nl  Tue Sep  4 19:34:37 2001
From: ivo at nospamAmaze.nl (ivo at nospamAmaze.nl)
Date: 4 Sep 2001 23:34:37 GMT
Subject: Mapping into two lists
References: 
Message-ID: <9n3oed$1i3$1@news1.xs4all.nl>

Marcus Stojek  wrote:
: Hi,

: I have a sorted list of int.  To generate an input file for
: a special software I have to split this list into two. Instead of
: explaining I'll give an example:

: List: [ 1, 3,4,5,6,7, 9, 11,12,13,14,15, 17]

: # start and end value of continuous list segment:
: Output list1: [3,7, 11,15] 
: # single values:
: Output list2: [1,9,17] 

The following code (no map() used) does what you want (if I understand
correctly what you want :)

l = [1, 3,4,5,6, 9, 11,12,13, 19, 21, 30,31, 77]

singles = []
ranges = []

cur = [ l[0] ]

for i in l[1:]:
    if i = cur[-1]+1:
        cur.append(i)
    else:
        if len(cur) == 1:
            singles.append(cur[0])
        else:
            ranges.extend([cur[0], cur[-1]])
        cur = [i]

if len(cur) == 1:
    singles.append(cur[0])
else:
    ranges.extend([cur[0], cur[-1]])

'cur' contains the current set you're working on, and it's initialized with
the first element of the original data. In each iteration, you check if the
new item 'extends the current set' or 'terminates the current set'. If it
does the latter, check the size of the set: if it's 1, it's a non-range,
else it's a range. Then you store them in the singles/ranges lists respectively.

At the end you have to check the reming set of the iteration. (you could
remove this check by doing 1 extra iteration by adding a guaranteed smaller
value to the list over which you iterate, i.e. "for i in l[:1] + [-1]",
or perhaps even [None], but that would ugly IMHO)

Btw, the algorithm will fail on an empty list.

Cheers,

	Ivo

-- 
Drs. I.R. van der Wijk                              -=-
Brouwersgracht 132                      Amaze Internet Services V.O.F.
1013 HA Amsterdam                                   -=-
Tel: +31-20-4688336                          Linux/Web/Zope/SQL
Fax: +31-20-4688337                           Network Solutions
Web:     http://www.amaze.nl/                    Consultancy
Email:   ivo at nospamAmaze.nl                         -=-

From jsnyder at trelis.com  Wed Sep 19 17:17:15 2001
From: jsnyder at trelis.com (jsnyder)
Date: 19 Sep 2001 14:17:15 -0700
Subject: peek poke for win32
Message-ID: 

Is there any python library function that will implement a simple
peek/poke to the PC parallel port, bypassing the HAL.  I did a deja
news search and only found things from 1998 or earlier.  Hopefully
someone has done this since then.

Joe Snyder

From pinard at iro.umontreal.ca  Sat Sep  8 12:40:09 2001
From: pinard at iro.umontreal.ca (=?iso-8859-1?q?Fran=E7ois?= Pinard)
Date: 08 Sep 2001 12:40:09 -0400
Subject: pymacs! :-)
In-Reply-To: <20010908115146.A935@bestweb.net>
References: 
	<6e0ad3b1.0109060128.6c9adc8@posting.google.com>

	 <20010908115146.A935@bestweb.net>
Message-ID: 

[Paul Winkler]

> You had written:

> lisp.global_set_key([lisp.f7], lisp.manglers_break_on_whitespace)

> So you want to put all the possible keys in the lisp namespace?  Seems
> messy.

My knowledge of English fails on me, here.  I do not understand your comment.
Would you be kind enough to explain?

Maybe you are worried with `[lisp.f7]' ?  There is nothing special with it.
[item] is a Python list, which yields a LISP vector.  `lisp.f7' merely
translates to the LISP symbol `f7'.  So, Python `[lisp.f7]' is LISP `[f7]'.

> And what about key combinations?  How would you say something like 'C-x w'?
> I would suggest simply writing them as strings, and the programmer
> will have to know the elisp way of naming them.  Example:

> lisp.global_set_key(['C-x w'], lisp.manglers_break_on_whitespace)

In LISP, this would be written:

   (global-set-key "\C-xw" manglers-break-on-whitespace)

Triggering this from Python requires that you write the string the
Python way, and Python does not recognise the "\C-" escape.  Knowing
that `C-x' is chr(0x18), one could write:

   lisp.global_set_key('\x18w', lisp.manglers_break_on_whitespace)

Maybe it could be useful to have a service function to help writing more
LISP-looking strings in Python?  `pymacs' does not have any service library
yet, but if the need arise, we can progressively build one.  Maybe there
would not be much things in it, if any.  Hard to know in advance.
I'd rather keep the API as bare as possible, if this is reasonable.

-- 
Fran?ois Pinard   http://www.iro.umontreal.ca/~pinard

From brian at sweetapp.com  Mon Sep 17 15:16:53 2001
From: brian at sweetapp.com (Brian Quinlan)
Date: Mon, 17 Sep 2001 12:16:53 -0700
Subject: Newbie Question
In-Reply-To: <000001c15029$b80374c0$aed1bfa8@c6e7e9>
Message-ID: <001001c13fad$4f9d5e50$445d4540@Dell2>

Mel wrote:
> My apologies for appearing to complain. I was simply trying to point
out
> that I had already done what you suggested, and had said so in my
original
> question.

I wasn't the one who answered your question; I just pointed out that you
were a bit rude to the one who did.

> However, when I use any of the suggested fixes things work just fine.
> Since I usually need much of the math modeule, my choice is to start
with
>          from math import *
> and similarly for the other modules that I  may need. But the other
fixes
> also work.,

I was not critiquing those solutions (though the frequent use of "from x
import *" statements should be avoided), I'm pointing out a
misconception that you might have about name lookup:

When python encounters an expression like this:

a()

It does two things:

1. It looks up the object associated with the name "a"
2. It calls that object

That is why Python said that a name/variable could not be found and not
a function; step one is only concerned with name lookup, it doesn't know
anything about the name's usage context.

Cheers,
Brian

From aahz at panix.com  Sat Sep 22 23:39:35 2001
From: aahz at panix.com (Aahz Maruch)
Date: 22 Sep 2001 20:39:35 -0700
Subject: Realtime capabilities?
References: 
Message-ID: <9ojlhn$q1k$1@panix2.panix.com>

In article ,
Tim Peters  wrote:
>
>This means that an Erlang process (unlike a Python thread) can't hog
>the CPU for a long time (provided the native OS is letting Erlang
>run).  In addition, the Erlang process scheduler guarantees fairness.
>Thus, and so long as Erlang is getting cycles, each Erlang process is
>"guaranteed" to get a timeslice before X seconds have passed (where
>X depends on lots of stuff, including the total number of Erlang
>processes running).  A programmer can exploit all that to deliver
>probabilistic bounds on response time.
>
>So "soft" means "no, we can't absolutely guarantee anything, but we've
>designed the language from the ground up to make it very likely that
>what we deliver in practice will be 'good enough', and provided you
>program intelligently in our model".

In other words, if the original poster is doing more than a tiny amount
of I/O, standard Python/OS threads will probably beat Erlang processes
for fairness, but if an application is almost completely compute-bound,
Erlang will probably beat even Stackless Python.
-- 
                      --- Aahz  <*>  (Copyright 2001 by aahz at pobox.com)

Hugs and backrubs -- I break Rule 6                 http://www.rahul.net/aahz/
Androgynous poly kinky vanilla queer het Pythonista   

We must not let the evil of a few trample the freedoms of the many.

From donn at drizzle.com  Mon Sep 24 00:41:04 2001
From: donn at drizzle.com (Donn Cave)
Date: Mon, 24 Sep 2001 04:41:04 -0000
Subject: Simple process IO capture (Was: "shell-commands" and python!) - process.py (0/1)
References: <9ogit0$e7c$1@newshost.accu.uu.nl>   
Message-ID: <1001306463.868543@yabetcha.drizzle.com>

Quoth Paul Moore :
[ ... pipe & fork wrapper ...]

| I did some looking. The attached is a fairly simple prototype of a module for
| process handling. The simple examples
|
|     >>> output = process.run("echo hello")
|     >>> print output
|     hello
|     >>> print process.run("tr a-z A-Z", input="hello")
|     HELLO
|
| are similar to shell "backticks", with the ability to provide input. There are
| features to allow merging of stdout and stderr, raise an exception if the
| command fails (the default action is to continue, but make the return code
| available as process.retval()), and set teh mode of the pipe (text or binary).
|
| It's a fairly simple wrapper around popen2/popen4, but it seems fairly useful to
| me. Comments anyone?
|
| I have ideas to work on this - things like allowing a sequence of strings as the
| "command", which acts like a Unix pipe (the plumbing is messy to set up, so
| encapsulating this might be nice...) or maybe some sort of class-based interface
| (but the simplicity of the examples above is important, and should remain).
|
| What do people think? Is this a useful idea?

Sure!  You probably won't be surprised to hear that it has been done
a couple of times before - because on one hand, it's useful, and as
you found, it isn't really terribly hard to do.

I don't know if anyone has pushed to get something like this into the
library.  Haven't looked at yours, but since you're working with popen2,
I wonder if you could work it up to be submitted as an enhancement to
that module?

Are you thinking about reading stderr for use in the exception?
I find that very useful, but deadlock potential with two separate
input sources will make you earn your pay.

	Donn Cave, donn at drizzle.com

From dale at riverhall.NOSPAMco.uk  Wed Sep 12 09:04:02 2001
From: dale at riverhall.NOSPAMco.uk (Dale Strickland-Clark)
Date: Wed, 12 Sep 2001 14:04:02 +0100
Subject: XML using standard Python modules
Message-ID: 

I'm trying to get to grips with XML using Python.

A simple app to start with, it will read a plain text file containing
some data, convert it to XML and write an XML file.

Later that file will be used as a random-access data source.

Where do I start?

I'm reading this: http://py-howto.sourceforge.net/xml-howto/SAX.html
at the moment. Is it up-to-date?

There seems to be half a dozen XML modules. Which is the right one for
this type of application? XML.SAX?

Thanks for any pointers.
--
Dale Strickland-Clark
Riverhall Systems Ltd

From dgrisby at uk.research.att.com  Sun Sep  2 16:47:14 2001
From: dgrisby at uk.research.att.com (Duncan Grisby)
Date: 2 Sep 2001 20:47:14 GMT
Subject: COM/CORBA/DCOP (was: Hello people. I have some questions)
References: 
Message-ID: <9mu5si$9gg$1@pea.uk.research.att.com>

In article ,
 Ignacio Vazquez-Abrams   wrote:

>> I don't know anything about DCOP but my guess is that it's closer to
>> COM than CORBA.  Most people considered CORBA too heavyweight for
>> connecting desktop apps and were surprised that ORBit (the Gnome ORB)
>> was able to get as good performance as it does.
>
>The difference was that MICO (KDE's ORB) was written in C++, while ORBit is
>written in C. ORBit has been tweaked and honed to death, whereas they could
>only do so much for MICO.

There's nothing inherently slow about C++ ORBs. MICO was never
designed for performance -- indeed its stated design goal is code
clarity and wide feature range at the expense of performance. Why the
KDE people didn't pick one of the better-performing C++ ORBs, I don't
know.

I don't know why people would consider CORBA too heavyweight for
connecting desktop apps -- the few performance comparisons between COM
and CORBA I have seen show CORBA to be as fast or faster than COM.

Cheers,

Duncan.

-- 
 -- Duncan Grisby  \  Research Engineer  --
  -- AT&T Laboratories Cambridge          --
   -- http://www.uk.research.att.com/~dpg1 --

From ignacio at openservices.net  Fri Sep 14 09:54:56 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Fri, 14 Sep 2001 09:54:56 -0400 (EDT)
Subject: Compiling MySQLdb ?
In-Reply-To: 
Message-ID: 

On Fri, 14 Sep 2001, Peter Moscatt wrote:

> "ld can't find -lz"
>
> ld is installed, so why can't it find -lz ??

Because zlib isn't installed.

-- 
Ignacio Vazquez-Abrams  

From aleax at aleax.it  Tue Sep 11 06:11:17 2001
From: aleax at aleax.it (Alex Martelli)
Date: Tue, 11 Sep 2001 12:11:17 +0200
Subject: COM/CORBA/DCOP (was: Hello people. I have some questions)
References:  <_Q2m7.21724$bY5.123263@news-server.bigpond.net.au> <9nahpm0qis@enews1.newsguy.com>  <9nfdb802r3n@enews4.newsguy.com> <6bcn7.35171$bY5.182509@news-server.bigpond.net.au>
Message-ID: <9nko0601t5j@enews3.newsguy.com>

"Neil Hodgson"  wrote in message
news:6bcn7.35171$bY5.182509 at news-server.bigpond.net.au...
    ...
> > >    So you are prepared to not follow the letter of the specification
for
> > >    the
> > > dispatch identifier? (Of course I can argue both sides :-) )
> >
> > Absolutely not!  Where are you reading this?!
>
>
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/automat/htm
> _hh2/chap5_61id.asp
>
> """dispIdMember
> Identifies the member. Use GetIDsOfNames or the object's documentation to
> obtain the dispatch identifier. """

Yes, and the object's documentation (if the object claims to support
COM and Automation) includes by reference the documentation of the
COM and Automation standards.  Therefore, by (e.g.) using DISPID_VALUE
directly as the (attempted) dispatch identifier, I'm following this --
and I have full right to expect an appropriate HRESULT from Invoke,
rather than a crash or any other form of exception, if the object
has no default-property and thus doesn't have any meaningful
implementation of DISPID_VALUE.

Alex

From DavidA at ActiveState.com  Wed Sep 19 19:47:42 2001
From: DavidA at ActiveState.com (David Ascher)
Date: Wed, 19 Sep 2001 16:47:42 -0700
Subject: Direct TK interface
References: <2764949.5mLc6kNg2l@lunix.schabi.de> <3BA7FC3F.D21E3A95@student.gu.edu.au>
Message-ID: <3BA92E9E.C180B0C@ActiveState.com>

Joal Heagney wrote:
> 
> Markus Schaber wrote:
> >
> > Hi,
> >
> > I was just wondering whether it is possible (and worth in sense of
> > speed etc.) to directly interface TK into python (without using the TCL
> > interpreter inbetween).
> >
> > markus
> 
> Don't know if this is what you want, but you can look up Rivet in the
> Vaults.

AFAIK, Rivet has been dead since before Tk 8.0

-- David Ascher
   ActiveState

   New! ASPN - ActiveState Programmer Network
   Essential programming tools and information
   http://www.ActiveState.com/ASPN

From joonas at olen.to  Tue Sep 18 08:33:29 2001
From: joonas at olen.to (Joonas Paalasmaa)
Date: Tue, 18 Sep 2001 12:33:29 GMT
Subject: Executing Perl CGI scripts with CGIHTTPServer
References: <3BA732F2.797D617A@olen.to>
Message-ID: <3BA73F64.F737CBD9@olen.to>

Joonas Paalasmaa wrote:
> 
> How can I use non-Python scripts with CGIHTTPServer.
> I would like use Python, but in this case I really must use Perl.

Strange. Perl scripts doesn't work on windows but does work on linux.
I think that this is some kind of os.fork issue.

From emile at fenx.com  Fri Sep 28 10:05:16 2001
From: emile at fenx.com (Emile van Sebille)
Date: Fri, 28 Sep 2001 07:05:16 -0700
Subject: How do I distinguish a string from a sequence?
References: 
Message-ID: <9p20be$ftrtb$1@ID-11957.news.dfncis.de>

"Paul Moore"  wrote in message
news:v3v8rtsdmp5ij8bqq7pfndnf6rihm3bujd at 4ax.com...
> Yes, I know, a string is a sequence...
>
> I'm thinking of writing a function which can take either a string, or a
sequence
> of strings, as an argument.

As long as you're still thinking about it, you could make the interface
non-ambiguous ala
def foo(cmdStr=None, cmdList=None):

> A simplified example would be treating a single
> string as a 1-tuple - something like
>
>    def foo(args):
>       if # args is a string:
>          args = (args,)
>       for arg in args:
>          print arg
>
> But I'm not sure how best to distinguish a string from a sequence

Maybe it's easier then to distinguish a sequence from a string?  ;-)

isinstance(args, .types.ListType)

HTH,

--

Emile van Sebille
emile at fenx.com

From ignacio at openservices.net  Mon Sep 10 17:59:08 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Mon, 10 Sep 2001 17:59:08 -0400 (EDT)
Subject: installation fails ?
In-Reply-To: <9njbdj$ml$1@fstgss02.tu-graz.ac.at>
Message-ID: 

On Mon, 10 Sep 2001, Armin Samide wrote:

> Hi,
>
> I'have downloaded the Python 2.1.1 source code package and wanted to build
> it on Windows with the Microsoft Visual C Compiler but a few headers are
> missing, as there are: zlib.h, xmlparse.h, db.h, tcl.h
> Are these headers included somewhere else or what else is wrong ?
>
> thanks,
> Armin

Python is dependent on a number of external libraries for some of it's
functionality. You need to get the libraries that contain those files: zlib,
expat, bsddb, Tcl/Tk, etc.

-- 
Ignacio Vazquez-Abrams  

From gahanr at gofree.indigo.ie  Sat Sep 15 09:08:34 2001
From: gahanr at gofree.indigo.ie (Robert Gahan)
Date: Sat, 15 Sep 2001 14:08:34 +0100
Subject: Python RE Query. 
Message-ID: 

Hi all,

I am trying to use Python RE to return the arguements associated with a
C function signature. Trying to "group" each parameter arguement by use of
parenthesis.

It does not seem to be working for me !!.
Can anyone give me a hand ??.

Thans again,
Rob.

import re

# I am trying to create a regular expression such that if given a C
signature, I can
# extract all of the parameter arguements
# e.g. for int print_date(char *date, char *month, char *year);
# I return say the following tuple -> ("char *date", "char *month",  "char
*year")

# The example below (tries to use !) groups where a given group would be
populated
# with each arguement. It only seems to match the last arguement.
# ... Can this apprach work ??.
# ... How can I get a match on all of the arguements ???.

args_from_signature = re.compile("^.* [\w]*?[(]((([^,]*?)[,]+)*?)[)][;]+",
re.DOTALL)

a = args_from_signature.match("int gg(int y);")
b = args_from_signature.match("int gg(int y, int z, int y, int p);")
c = args_from_signature.match("int ggz;")

print a
print b
print b.groups()

From tim at vegeta.ath.cx  Tue Sep 11 04:33:52 2001
From: tim at vegeta.ath.cx (Tim Hammerquist)
Date: Tue, 11 Sep 2001 08:33:52 GMT
Subject: Python and Zope
References:  <9nettc$ce1$1@slb7.atl.mindspring.net>         
Message-ID: 

Me parece que Oleg Broytmann  dijo:
> On Mon, Sep 10, 2001 at 11:30:12PM +0000, Tim Hammerquist wrote:
> > >    We are talking about "Apache vs web-application servers". In this
> > > context modules are so like CGIs (forked and killed) so I don't need to
> > > make a distinction.
> > 
> > We probably just have a Point-Of-View problem.  I'm thinking of CGI in
> > the strict sense of an application designed to produce web content using
> > STD filehandles and environment variables.  In all fairness, my ftpd
> > conforms to your (most recent) definition of CGI, as do half of the
> > daemons on my system.
> 
>    In this "web-application server" context - they are! :) Because thay
> cannot hold a persistent DB connection.

I don't remember persistence of DB connections being mentioned in the
CGI spec.  I don't believe databases are mentioned at all.

The fact that they are not constantly running indefinitely does *not*
make them a subset, superset, or *any* kind of set of the Common
Gateway Interface.

In fact, to find a list of files on any system that qualify as CGI's
according to your most recent definition, just run the following command:

$ find / | grep -v 'mod_'

> > I probably took offense to the picture you painted of Apache, being a
> > ruthless, discompassionate Nazi of a daemon, kill arbitrarily, which
> > is, of course, not true.
> 
>    If I have a module that have opened DB connection - how can I prevent
> Apache from killing the child (because I want to hold that connection
> open)?

Apache's process housekeeping is neither ruthless, nor arbitrary, nor
random (in any sense I've ever been aware of).

If nothing else, your tirade reflects your dislike of Apache's
housekeeping methods, and your disapproval of mod_(perl|python)'s
handling of persistent db connections.

However, your, shall we say, "flexibility" with the meaning of words is
reminiscent of Humpty Dumpty: "Words mean whatever I want them to mean."
Nevertheless, you have a luminous future in Microsoft's marketing
division.

With that in mind, what does the word *plonk* mean to you?

-- 
I am following my fish.
    -- Delirium, The Sandman

From unknown at lee-morgan.net  Sun Sep 30 21:37:47 2001
From: unknown at lee-morgan.net (Lee Morgan)
Date: Mon, 01 Oct 2001 01:37:47 GMT
Subject: How do Java interfaces translate to Python?
References:   
Message-ID: 

Gordon Tyler  writes:

> In article , Martin von Loewis
 wrote: 
> > What exactly is it that you do with interfaces in Java?
> 
> Enforcing a contract between objects, i.e. if you want to work with this
> object, your object must implement this interface.
> 
> I find myself unable to think of anything other than that. Which suggests
> to me that perhaps interfaces aren't such a useful construct after all. ;)
> 
> I suppose the thing I'm really missing is compile-time type safety. Yes I
> know that Python is a dynamically typed language and as such compile-time
> type safety, compiling even, make no sense. But do you have any
> suggestions for somebody used to compiled languages on how to deal with a
> dynamically typed language like Python? I find myself making silly
> syntactical mistakes which I just don't see when I visually scan the code,
> and when I run the program it suddenly barfs in the middle of nowhere with
> a syntax error. Very frustrating. Especially, if it takes a few minutes
> and interaction from me to get to that point.
> 

Yeah, I've often got caught out by this myself. Also silent name bindings to
classes (which you sometimes want) got me recently.

There is a PEP for an interface enhancement, but its a still a dynamic
enforcement, so instead of 

Traceback (innermost last):
  File "", line 1, in ?
Interface.Exceptions.BrokenImplementation:
An object has failed to implement interface FishMarketInterface

you would get

Traceback (most recent call last):
  File "", line 1, in ?
AttributeError: 'm' instance has no attribute 'getFishMonger'

which to my mind isn't an improvement.

If interfaces aren't checked at byte-compile time surely they just become a code
documentation feature - perhaps useful to utils like pychecker but unlikely to
get regular use.

(Granted I've only just started looking at Interfaces in python as I wanted to
stop getting bitten in the arse, even if they were my teeth - but interface's as
suggested in the PEP don't seem to address the problem)

Some wistful folks on this list purport the idea that python programmers need
to know what they're doing so they don't need any sort ot type checking. Whilst
this could well be true, under the hot iron of commercial development you need
to come back to old code, quickly understand it, and be confident in making
changes. Yes you could unit test extensively, but some situations make this
tricky (gui apps for example).

Anyway, sorry about the rant - I wanted interfaces to help me with the same
problem you're having and I'm confused they wont. I'd hate to loose Pythons
dynamic nature, but sometimes I want a little support.

But, given python's lisp like dynamism you can enforce your own with varying
degrees of success. One caveat - I'm still playing with ways to do this as my
understanding of python grows and haven't found one I really like. Also the
recently added inspect.py module can help here.

# This class raises error if attr not one set in init func
# It won't help complex objects, ie when __setattr__ isnt called
class _base:
    initialising = 1
    def __init__(self):
        self.attrONE = 1
        self.initialising = 0
    def __str__(self):
        return str(self.attrONE) + str(self.initializing)
    def __setattr__(self,attr,value):
        if self.initialising:
            self.__dict__[attr] = value            
        else:
            if self.__dict__.has_key(attr):
                self.__dict__[attr] = value
            else:
                raise self.__class__.__name__ + " does not have attr " + attr
    def foo(self):
        pass

me = _base()
me.attrONE = 3
me.attrONE = 5
me.attrOEN = 4	# error raised

# check some attr
def enforceInterface(instance, requiredAttr = ['foo','foo2']):
  for attr in requiredAttr:
    if not hasattr(instance,attr):
      raise instance.__class__.__name__ + " is missing attribute " + attr

#check at top level
enforceInterface(me) # error on foo2

-- 
Lee Morgan

From mertz at gnosis.cx  Mon Sep  3 15:18:42 2001
From: mertz at gnosis.cx (Lulu of the Lotus-Eaters)
Date: Mon, 03 Sep 2001 15:18:42 -0400
Subject: Is 0 > None?? (fwd) (fwd)
Message-ID:                 

"Alex Martelli"  wrote:
> >>> u'cia?'<'cia?'
> Traceback (innermost last):
>   File "", line 1, in ?
> UnicodeError: ASCII decoding error: ordinal not in range(128)

|Well, yes -- though the problem is not with the Unicode strings
|(as I've shown, you can perfectly well compare them to anything:-)
|The issue, it seems to me, is quite different wrt complex
|numbers -- in that case, there is _no_ setting that lets you
|default-sort an heterogeneous list that may contain a complex
|number somewhere.  The Unicode issue might be finessed in
|several ways.  The complex-number one is starker IMHO.

I don't understand the differenence Alex points to.  For example, the
below cases seem awfully similar:

    >>> # Try to sort Unicode values in list
    >>> lst = [ 128, chr(128), unichr(128), 'a' ]
    >>> lst
    [128, '\x80', u'\x80', 'a']
    >>> lst.sort()
    Traceback (most recent call last):
      File "", line 1, in ?
    UnicodeError: ASCII decoding error: ordinal not in range(128)
    >>> # Try to sort complex numbers in list
    >>> l2 = [ 1, 1.0, 1+1j ]
    >>> l2
    [1, 1.0, (1+1j)]
    >>> l2.sort()
    Traceback (most recent call last):
      File "", line 1, in ?
    TypeError: cannot compare complex numbers using <, <=, >, >=

What can I do to get 'lst' to sort properly?  If the answer is to use a
custom comparison function, I can do likewise with complex numbers.  I
suppose one could say the problem was with the 'chr(128)' element rather
than the 'unichr(128)' element... but such a characterization doesn't
particularly bring a solution closer.

Yours, Lulu...

P.S. The thing that could be fixed in a later Python is the
non-universal comparison... we are stuck with 'print >>' for backwards
compatibility.

From warkid at storm.ru  Fri Sep  7 03:48:24 2001
From: warkid at storm.ru ( Kerim Borchaev ( WarKiD ) )
Date: Fri, 7 Sep 2001 11:48:24 +0400
Subject: Customizing module globals
In-Reply-To: 
References: 
Message-ID: <7491.010907@storm.ru>

Thursday, September 06, 2001, 11:11:43 PM, Terry Reedy answered my
question:
>> Can I specify what module's to be imported symbol table will be?
>>
>> Say I have a module named Module that assumes that there's an object
>> Object without implicit declaration like this :
>>
>> Module.py
>> ----------------
>> Object.doThings()
>> ----------------
>>
>> And I can import/run this module with specific a Object?

TR> You can set module attributes in the obvious manner.

TR> import module
TR> module.Object = 

But te problem is that import fails...

  File "ModuleUser.py", line 1, in ?
    import Module
  File "Module.py", line 1, in ?
    Object.doThings()
  NameError: name 'Object' is not defined

Best regards,
 Kerim                            mailto:warkid at storm.ru

From markus at schabi.de  Mon Sep 17 08:52:32 2001
From: markus at schabi.de (Markus Schaber)
Date: Mon, 17 Sep 2001 14:52:32 +0200
Subject: Proposed PEP for a Conditional Expression
References:  <9nidrm01j7q@enews1.newsguy.com> <23891c90.0109130146.60a98909@posting.google.com> <3ba21452$0$51376$edfadb0f@dspool01.news.tele.dk>
Message-ID: <1081165.6gNhbJn0HT@lunix.schabi.de>

Hi,

maxm  schrub:

> Besides ... what could be simpler than using the fact that booleans in
> Python is either 1 or 0:
> 
> #################################
>>>> a=3
>>>> b=4
>>>> print ('number two', 'number one')[a < b]
>>>> number one

This does not short-cirquit evaluate.

> or if you want to get the result of a functionwith only the choosen
> function evaluated:
> 
> #################################
>>>> def n1():
>>>>     return 'Number one'
>>>> def n2():
>>>>     return 'Number two'
>>>> print (n2, n1)[a < b]()
>>>> Number one
> 
> Any sane Python programmer will grasp those IMMEDIATELY!

That does short-cirquit, but has limits on the expressions you can use 
as n1 and n2 (may be that gamma and nested scopes help here).

markus

-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From sholden at holdenweb.com  Wed Sep 12 20:08:25 2001
From: sholden at holdenweb.com (Steve Holden)
Date: Wed, 12 Sep 2001 20:08:25 -0400
Subject: [OT] Strange IE5.5 Caching Behavior
References: 
Message-ID: 

"Ignacio Vazquez-Abrams"  wrote in message
news:mailman.1000171888.20415.python-list at python.org...
> On Mon, 10 Sep 2001, Steve Holden wrote:
>
> > Sorry about this post being off-topic, but c.l.py is the largest
collection
> > of web-heads I have easy access to. If you know nothing about HTTP,
please
> > ignore this.
> >
[description of puzzling browser failure to use Last-Modified headers
appropriately]
> >
> > regards
> >  Steve
>
> What is the clock skew between the client and server?
>
I have *no* idea why, but suddenly IE5 is quite happily causing the server
code to generate 301 responses for graphics that have not been modified. Who
knows why the problem occurred in the first place?

don't-you-just-hate-it-when-you-don't-discover-the-problem-ly y'rs  - steve
--
http://www.holdenweb.com/

From peter at engcorp.com  Fri Sep  7 10:02:05 2001
From: peter at engcorp.com (Peter Hansen)
Date: Fri, 07 Sep 2001 10:02:05 -0400
Subject: how to run python script from Unix Shell?
References:  <3B983E3A.139A8B71@engcorp.com> <3B98C6DF.FCC22D4E@student.gu.edu.au>
Message-ID: <3B98D35D.AE6F52D0@engcorp.com>

Joal Heagney wrote:
> 
> Peter Hansen wrote:
> > The other problem could be that your python is not
> > really in /usr/bin (type "which python" to be sure)
> > but then your error message would say:
> >
> > bash: ./test.py: No such file or directory
> >
> > (This all on Red Hat release 7.1.)
> 
> If this is so, you may want to try the magic hack
> #!/usr/bin/env python

Would this find the executable if it were not in the
path somewhere else?  If not, then it doesn't solve
the possible problem I described above.

Besides, then you have a bunch of scripts with 
non-conventional stuff in the first line, instead of
the "standard" #!/usr/bin/python.  Probably better
to just fix the environment to work with that, so 
you don't have to rewrite scripts you download, or
modify scripts you upload...

-- 
----------------------
Peter Hansen, P.Eng.
peter at engcorp.com

From pinard at iro.umontreal.ca  Tue Sep  4 14:25:19 2001
From: pinard at iro.umontreal.ca (=?iso-8859-1?q?Fran=E7ois?= Pinard)
Date: 04 Sep 2001 14:25:19 -0400
Subject: pymacs! :-)
In-Reply-To: 
References: 

Message-ID: 

> > Second, I'd like to find a way for any function or variable
> > which is not defined in Python to be resolved within Emacs if
> > possible: the idea is to use Emacs elegantly from Python, using
> > Python syntax for function calls, without explicitly resorting to
> > `eval_lisp("LISP-EXPRESSION")'.

[Marcin 'Qrczak' Kowalczyk]

> I would use something like
>     lisp.variable_name
> where lisp is an object with a suitable __getattr__.

This traversed my mind.  I wanted to avoid such `lisp.' prefix, a bit
because they might become cumbersome, but mostly because they force users
to well remember if a function is implemented in LISP or not, and I would
prefer that this be made a transparent implementation detail.

On the other hand, thinking again about it, I wonder why I hesitate using
`emacs.point()', when it does not bother me to write `string.join(...)'.
There is indeed some name-space cleanliness at sticking to such prefixes.
I'll think more on this.  Thanks for the triggering!

-- 
Fran?ois Pinard   http://www.iro.umontreal.ca/~pinard

From ignacio at openservices.net  Mon Sep 17 01:59:36 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Mon, 17 Sep 2001 01:59:36 -0400 (EDT)
Subject: Getting all possible combinations of list items
In-Reply-To: <3ba58893$0$330$6e49188b@news.goldengate.net>
Message-ID: 

On Mon, 17 Sep 2001, Greg Krohn wrote:

> Does anyone know of how I should go about generating a list whose keys are
> all the possible combinations of the items in another list?
> e.g.
>
> another_list = ['a', 'b', 'c']
>
> magic_algorithm(another_list) -> ['aa', 'ab', 'ac', 'ba', 'bc', 'bc', 'ca',
> 'cb', 'cc']
>
> I know I could do this easily with nested 'fors', but that requires me to
> know the length of the set. Is this a case for recursive functions? I hope
> not, those things scare me. BTW, each item in another_list will be unique,
> if that matters.

This solution treats the items in listin as values in a number system with the
radix equal to the number of items in the list and the number of positions in
count:

---
def magic_algorithm(listin, count):
  for i in listin:
    if type(i)!=type(''):
      raise TypeError, 'all items in list passed to magic_algorithm must be strings'
  l=len(listin)
  return map(''.join, map(lambda x, count=count, l=l, listin=listin: map(lambda y, x=x, count=count, l=l, listin=listin: listin[((x/(l**y)) % l)], range(count)), xrange(l**count)))
---

---
>>> magic_algorithm(['a', 'b', 'c'], 2)
['aa', 'ba', 'ca', 'ab', 'bb', 'cb', 'ac', 'bc', 'cc']
>>>
---

-- 
Ignacio Vazquez-Abrams  

From ignacio at openservices.net  Mon Sep 17 12:11:06 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Mon, 17 Sep 2001 12:11:06 -0400 (EDT)
Subject: PEP proposal for round(x,n) enhancement
In-Reply-To: <1226862.F50zNuYjNa@lunix.schabi.de>
Message-ID: 

On Mon, 17 Sep 2001, Markus Schaber wrote:

> Tim Peters  schrub:
>
> > BTW, complex numbers still have no meaning to round(), so you could
> > use round(x, 3j) to mean "round to 3 significant digits" .
>
> Ouch.
>
> This "solutions" needs rather complex programmer brains :-)

Naw, just multiply by -1j and take the real component.

-- 
Ignacio Vazquez-Abrams  

From pobrien at orbtech.com  Wed Sep 12 21:24:12 2001
From: pobrien at orbtech.com (Patrick K. O'Brien)
Date: Thu, 13 Sep 2001 01:24:12 GMT
Subject: ANNOUNCE: PyCrust 0.6 is fresh out of the oven!
Message-ID: <0VTn7.3722$lE3.353067@newsread2.prod.itd.earthlink.net>

PyCrust 0.6 is available for tasting. In particular, PyCrust now
comes with PyShell and PyFilling.

PyCrust - The Flakiest Python Shell
Half-baked by Patrick K. O'Brien (pobrien at orbtech.com)
======================================================

What is PyCrust?
----------------
PyCrust is an interactive Python environment written in Python.
PyCrust components can run standalone or be integrated into other
development environments and/or other Python applications.

PyCrust comes with an interactive Python shell (PyShell), an
interactive namespace/object tree control (PyFilling) and an
integrated, split-window combination of the two (PyCrust).

What is PyCrust good for?
-------------------------
Have you ever tried to bake a pie without one? Well, you
shouldn't build a Python program without a PyCrust either.

Where can I get the latest release of PyCrust?
------------------------------------------------------------
The latest PyCrust releases are available at:
http://sourceforge.net/project/showfiles.php?group_id=31263

What else do I need to use PyCrust?
-----------------------------------
PyCrust requires Python 2.1 or later, and wxPython 2.3.1 or later.
PyCrust uses wxPython and the Scintilla wrapper (wxStyledTextCtrl).
Python is available at http://www.python.org/.
wxPython is available at http://www.wxpython.org/.

---
Patrick K. O'Brien
Orbtech (http://www.orbtech.com)
"I am, therefore I think."

From cce at clarkevans.com  Fri Sep  7 08:59:01 2001
From: cce at clarkevans.com (Clark C . Evans)
Date: Fri, 7 Sep 2001 08:59:01 -0400
Subject: list comprehensions: sorting?
In-Reply-To: <9na4190avo@enews1.newsguy.com>; from aleax@aleax.it on Fri, Sep 07, 2001 at 11:29:12AM +0200
References:  <9n7aim020of@enews1.newsguy.com>  <9na4190avo@enews1.newsguy.com>
Message-ID: <20010907085901.A25254@doublegemini.com>

On Fri, Sep 07, 2001 at 11:29:12AM +0200, Alex Martelli wrote:
| And if you can think of some 'orderby' syntax that 
| would actually cover ALL typical sorting needs with 
| just "a bit" of extension to the current one, we could
| surely write a PEP for it -- but it would HAVE to be
| "just a bit" (of extra syntax), and for very wide generality 
| gains, or the trade-off is a losing one, I fear.

Consider the following pattern...

   [ vSelect for vAs in vFrom if vWhere sortby vOrder ]

This could be expanded into a farily generic processing
template where vOrder is any expression..

  sortby = 1
  temp = []
  for vAs in vFrom:
      if vWhere:  
          val = process(x)
          if sortby: val = (vOrder,val) 
          temp.append(val)
  if sortby:
      temp.sort()
      if is_desc: temp.reverse()
      sorted = []
      for x in temp: sorted.append(x[1])
      temp = sorted
  return temp

The primary problem is that sort has a few "arguments",
as to sort descending/ascending or to do a stable sort;
how about taking a function like syntax? sortby(desc,stable)

Thoughts?

Clark

P.S. I also had a very fuzzy idea in my head about
     a syntax extension registry function.  This may
     be way too powerful; but it appears all of the
     list extensions could be expressed as re-writes
     of the parse tree (before compile).  So, we could
     add a function like...

     register regex, rewrite_function

     In this way "statements" which were not recognized
     by the parser would be passed through the regex of
     each registered rewrite rule.  If the rewrite matched,
     then the rewrite_function would be called on the 
     statement at compile time to produce a representation
     that is in the core language.

     Pretty powerful... probably too powerful.

From ignacio at openservices.net  Mon Sep 17 00:00:17 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Mon, 17 Sep 2001 00:00:17 -0400 (EDT)
Subject: How to parse XHTML with xml.parsers.xmlproc?
In-Reply-To: <873d5mo5cz.fsf@zazu.vip.fi>
Message-ID: 

On 17 Sep 2001, Paavo Hartikainen wrote:

> I managed to understand enough of the xml.parsers.xmlproc to feed data
> to it.  File I am trying to parse is valid XHTML but I have not
> managed to make my xmlproc.XMLProcessor to parse according to correct
> DTD in file "DTD/xhtml1-strict.dtd".

You might want to try the 4Suite mailing list:

  http://lists.fourthought.com/mailman/listinfo/4suite

-- 
Ignacio Vazquez-Abrams  

From rnd at onego.ru  Sat Sep  8 02:12:04 2001
From: rnd at onego.ru (Roman Suzi)
Date: Sat, 8 Sep 2001 10:12:04 +0400 (MSD)
Subject: Pythonwin and .NET
In-Reply-To: <3B997A5E.6010801@bigpond.net.au>
Message-ID: 

On Sat, 8 Sep 2001, Mark Hammond wrote:

>Maan Hamze wrote:
>
>> This is a question for Mark Hammond.

>I honestly do not know where Python and Perl really will fit in this new
>world.  .NET imposes certain requirements on programs, so that the
>benefits of .NET can be realized.  However, these requirements can often
>work against languages such as Python.  The dynamic and introspective
>nature of Python is unlikely to be able to be exploited, unless .NET
>itself grows these same capabilities - and when .NET grows them, we can
>expect C# to also grow them.

I thought .NET has some kind of assembly-like bytecode, so Python could
just compile into it (like Jython to Java's).  If this is not true and
.NET's lowest level is higher than Java's bytecode level, .NET will not
make serious impact. Nobody will buy single highlevel language platform
even from MS. (However, who could imagine several years ago that MS
Windows will be 95% on the desktops?). No. This will not happen with
developers!

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Saturday, September 08, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "Aren't cats just widdle furry balls of love?" _/

From aleax at aleax.it  Fri Sep  7 12:42:47 2001
From: aleax at aleax.it (Alex Martelli)
Date: Fri, 7 Sep 2001 18:42:47 +0200
Subject: Nested scopes: why is it weird?
References: <3B98F3B0.53AC2524@swiftview.com>
Message-ID: <9nated01mmc@enews2.newsguy.com>

"Scott Long"  wrote in message
news:3B98F3B0.53AC2524 at swiftview.com...
> Nested scopes seem like a nice addition (of course!) but there are some
> weird things about it. Take a look:
>
> >>> from __future__ import nested_scopes
> >>> def a():
> ...   def b():
> ...     k = x
> ...     print k
> ...   x = 1
> ...   b()
> ...
> >>> a()
> 1
>
> Right, this is what you would expect. But how about this?
>
> >>> from __future__ import nested_scopes
> >>> def a():
> ...   def b():
> ...     k = x
> ...     x = 0
> ...     print k
> ...   x = 1
> ...   b()
> ...
> >>> a()
> Traceback (most recent call last):
>   File "", line 1, in ?
>   File "", line 7, in a
>   File "", line 3, in b
> UnboundLocalError: local variable 'x' referenced before assignment
>
> Here is my explanation for this (tell me if I'm wrong):
>
> During pass #1 of compilation, the statement "x = 0" in b() binds x as a
> local variable local to b(). During execution, k = x executes *before* x
> has been assigned, resulting in this flamage.
>
> My first beef here is, why is the exception called UnboundLocalError?
> The variable is certainly bound (into the local scope), it simply has
> not been assigned. Why not call it UninitializedLocalError? I know it
> isn't going to change, I'm just asking.
>
> But my main concern is that this way of selecting a binding seems very
> unintuitive. Shouldn't the first statement referencing x be the
> statement that specifies the binding of x? In this case, shouldn't "k =
> x" cause x to get bound as a free variable, not a local to b()? I'm not
> claiming that this is a bug. I am curious as to why it was decided that
> things are going to work this way. It makes assignment to a variable in
> an enclosing scope impossible!
>
> Regards,
> Scott

From markus at schabi.de  Fri Sep 14 05:34:53 2001
From: markus at schabi.de (Markus Schaber)
Date: Fri, 14 Sep 2001 11:34:53 +0200
Subject: Proposed PEP for a Conditional Expression
References:  <3BA00239.DECE6412@cosc.canterbury.ac.nz>  
Message-ID: <5293894.qXVLH7GnMW@lunix.schabi.de>

Hi,

Gareth McCaughan  schrub:

> It isn't exactly like C, because the C syntax doesn't
> abuse the word "if". If you use words from a natural
> language, it is best to use them in a way reasonably
> compatible with that language. " if  ..."
> completely fails this test, and I too think it could only
> appeal to someone who'd got used to it by programming in
> Forth.

What about "(: return  [else return :  [else ])" would be usable.

In my thinking of natural and mathematical language, the : is a way of 
indicating that the condition proposes the expression.

markus
-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From smt at pacific.net.hk  Thu Sep 13 11:10:13 2001
From: smt at pacific.net.hk (Kenneth Tsang)
Date: Thu, 13 Sep 2001 23:10:13 +0800
Subject: MUDs...
References: 
Message-ID: <9nqic4$and$1@hfc.pacific.net.hk>

hi, I come across this. - Pythonic MOO
http://www.strout.net/python/poo/index.html

KT
--

--
Kenneth Tsang
email: smt at pacific.net.hk tel: +852 9468 4772
"Vincent A.Primavera"  wrote in message
news:mailman.1000384156.22009.python-list at python.org...
> Hello,
> A while ago on the list, Python based MUDs were discussed.  Does anyone
have any suggestions as to
> which were/are recommended?
>
> Thank you,
> Vincent A. Primavera.
>

From niemeyer at conectiva.com  Wed Sep  5 12:06:27 2001
From: niemeyer at conectiva.com (Gustavo Niemeyer)
Date: Wed, 5 Sep 2001 13:06:27 -0300
Subject: string.split
In-Reply-To: <9n4lj3014la@enews1.newsguy.com>; from aleax@aleax.it on Wed, Sep 05, 2001 at 09:52:02AM +0200
References:  <9n4lj3014la@enews1.newsguy.com>
Message-ID: <20010905130627.A6283@tux.distro.conectiva>

Hi there!

> > set a literal string that is the seperator. How do I split on any or all
> > occurrences of (for example) whitespace and a comma, without using
> regexes.
> > I mean string.split() must be able to do it anyway to achieve the default
> > behaviour.
> 
> Nope -- look at objects/stringobject.c: string_split specialcases out
> a call to split_whitespace when the splitter argument is missing or
> None, and split_whitespace uses C's isspace to check for splitting.
> 
> I think it's a reasonable feature-request to wish for split to be
> able to split on any one of several strings (e.g., make it callable
> with several string arguments, or maybe with an argument that's a
> sequence of strings), but feature-request it is -- it would need
> additional code in stringobject.c.  So, you're advised to submit it
> as a feature request to sourceforge.

Don't waste your time. I thought this would be a resonable feature and
implemented a splitlist() method for strings, doing exactly this. After
some discussions, it has been decided by the python crew that re.split
was enough and adding a new functionality like this would "bloat" the
code.

If you want more information about this, have a look at python's patches
at sourceforge. If you can't find it and want me to send the patch for
research purposes, let me know.

-- 
Gustavo Niemeyer

[ 2AAC 7928 0FBF 0299 5EB5  60E2 2253 B29A 6664 3A0C ]

From skip at pobox.com  Fri Sep  7 00:25:39 2001
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 6 Sep 2001 23:25:39 -0500
Subject: How to convert a time object from MS Access database to string
In-Reply-To: <3B98B2E5.21359.BE999F@localhost>
References: 
        <3B98B2E5.21359.BE999F@localhost>
Message-ID: <15256.19523.166611.249868@localhost.localdomain>

    Ng> How I can convert a time object read from the MS Access Database to
    Ng> a string.

    Ng> I checked the PyTime Object and used the example as follows:

    Ng>   rdate = time.localtime(int(rec[3]))

    Ng> but got the following error:

    Ng>   TypeError: object can't be converted to int

Well, obviously rec[3] doesn't look like an integer.  What does it look like
if you just print it out?  If it looks like a complex date/time sort of
thing like 

    Thu April 1 2001 10:38

you can probably parse it with time.strptime or use the functions available
in Marc-Andre Lemburg's mx.DateTime module to parse it.

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/

From lac at strakt.com  Thu Sep 27 07:02:05 2001
From: lac at strakt.com (Laura Creighton)
Date: Thu, 27 Sep 2001 13:02:05 +0200
Subject: return command in a function. 
In-Reply-To: Your message of "Thu, 27 Sep 2001 01:44:10 GMT."
Message-ID: <200109271102.f8RB25Ev005796@ratthing-b246.strakt.com>

Brian Lee:
> I think that commands are like ``goto'' It is very confused for me to 
> understand big code because such commands jump un-excepted line.

'un-excepted'?

1. Do you mean `The code jumps in ways I don't _expect_'?  
or
2. `The code should use the python Exception mechanism, but doesn't.'

If 1. you are probably confusing cause and effect.  The code is bad,
and _in addition_ it uses breaks and continues, and has a return 
statement in the middle of it.  Rewrite it.  Since it's 'big code'
try rewriting it _smaller_ in _more pieces_. Perhaps it could benefit
from being more Object-Oriented; without seeing it I can't tell, but
that is often the case with huge pieces of code that return in many 
different places.  

If 2. Very likely.

Laura Creighton

From BPettersen at NAREX.com  Thu Sep 27 13:03:01 2001
From: BPettersen at NAREX.com (Bjorn Pettersen)
Date: Thu, 27 Sep 2001 11:03:01 -0600
Subject: file find module
Message-ID: <6957F6A694B49A4096F7CFD0D900042F6C9E59@admin56.narex.com>

> From: mallum [mailto:breakfast at 10.am]
> 
> Hi all;
> 
> Does a module exist ( pref in standard dist ) that will recursively
> search directorys for filenames matching a certain pattern ( like
> Perl's File::Find ) - or will I have to write something for scratch ?

There's find.py in Lib/lib-old, but it will probably go away so better
make your own copy...

-- bjorn

From vincent_delft at yahoo.com  Thu Sep 20 09:47:47 2001
From: vincent_delft at yahoo.com (vincent delft)
Date: Thu, 20 Sep 2001 15:47:47 +0200
Subject: bsddb3 vs zodb
References: <3BA9A72A.1D5A6067@yahoo.com> <9ocbso$m72$1@slb7.atl.mindspring.net>
Message-ID: <3BA9F383.9ED5C436@yahoo.com>

I just would like to have a very small DB with concurrent read and write.

I've a daemon collect data and store them into the DB.

But I've other processes (not deamon) that will read and write into the same
DB.

I've founded bsddb3 and zodb that can match those simple requirements.
But ZODB is maybe too sophisticate for my simple problem.
What about the performances (how many read/write per seconds, what about the
memory used by those solutions, ...)

Andrew Dalke wrote:

> vincent delft wrote:
> >does any one as analyze the pro and cons (functionalities, performances,
> >...) between Berkley DB3 (bsddb3) and ZODB ?
>
> They aren't the same.
>
> bsddb3 does key/value mappings, where both terms are strings.
> This is extremely useful.  But if you don't have strings you
> need to tell it how and when to do the conversion.  There
> is support for an automatic pickling interface for adding and
> removing elements from the database, but it doesn't know
> about changes to the data structure once it's pulled out of
> the database, and it doesn't deal well with having data shared
> across different elements.
>
> ZODB is a full object persistence system, meaning you can
> keep your data as a Python data structure and let ZODB figure
> out how to store that data - there's no need for explicit
> data structure to/from file I/O code.  (So long as your object
> supports pickles.)
>
> ZODB supports bsddb3 as one way of doing storage.
>
>   http://www.zope.org/Wikis/ZODB/BerkeleyStorage
>
> What are you trying to do?  That makes it easier to answer
> your question.
>
>                     Andrew

From rnd at onego.ru  Thu Sep 20 13:16:14 2001
From: rnd at onego.ru (Roman Suzi)
Date: Thu, 20 Sep 2001 21:16:14 +0400 (MSD)
Subject: pgdb bug?
Message-ID: 

Well, here is the fragment which works differently
when cur is from MySQLdb or pgdb modules:

...
cur.execute("""SELECT name, path FROM modules;""")
while 1:
  record = cur.fetchone()
  if not record:
    break
  print record
...

With MySQLdb all records are printed (158 records).
With the pgdb - 1st record is printed 158 times ;-)

.fetchall() works as expected.

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Thursday, September 20, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "A big enough hammer fixes anything" _/

From reqhye72zux at mailexpire.com  Sun Sep 16 09:44:09 2001
From: reqhye72zux at mailexpire.com (Robert Amesz)
Date: Sun, 16 Sep 2001 13:44:09 -0000
Subject: [Tutor] SMTPLIB module - how to add subject ?
References: <3BA3D9FE.30092.76C3D5@localhost> 
Message-ID: 

Sheila King wrote:

> On Sat, 15 Sep 2001 22:45:18 +0200, "A"   wrote
> about [Tutor] SMTPLIB module - how to add subject ?:
> 
> I've pasted the example below. Actually, I really dislike this
> example. They are using
> "\r\n"
> as a character for newlines. Whose idea was that???
> It should be just
> "\n"

Not so: the RFC's specify CR/LF pairs as line separators. The downside 
is that you must make sure that under Windows or MacOS the line-endings 
aren't translated somewhere along the way.

Robert Amesz

From skip at pobox.com  Thu Sep  6 18:39:14 2001
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 6 Sep 2001 17:39:14 -0500
Subject: Performance of list comprehensions vs. map
In-Reply-To: <3B97EB8D.D64CE8F0@home.net>
References: <3B966B1C.120D0AF6@home.net>

        <3B96C062.99E36B04@home.net>

        <3B97EB8D.D64CE8F0@home.net>
Message-ID: <15255.64274.189905.782033@localhost.localdomain>

    >> No, this is Python's principle of least astonishment at work.
    >> Python's language is dynamic all over the place.  Placing arbitrary
    >> restrictions on those semantics because they happen to occur between
    >> "[" and "]" would have been wrong.

    Chris> but it's not wrong to put in the same restrictions when map is
    Chris> called?  The list comprehension syntax is new.. it's not legal in
    Chris> older version of Python. Therefore, you could put any
    Chris> restrictions you wanted in there, and the restiction that the
    Chris> lists being comprehended don't change in the middle ofhte process
    Chris> sounds like a pretty darn good one to me.

I think you're still missing what I was saying.  map() *can't* possibly have
the same semantics as for loops precisely because it doesn't return control
to the interpreter where the name->object lookup takes place.  Could list
comprehensions behave that way?  Yes, but in my opinion (and apparently in
the opinion of the various powers that be), that would be wrong.  If you
don't like all that dynamism, maybe Python's not the language for you.  I
like it and am interested in speeding up the language as it exists, not some
other language with Python's syntax but less dynamic semantics.

    Chris> If it's OK from a design standpoint to require that the function
    Chris> in a map is bound once, it seems pretty reasonable to have the
    Chris> same requirement for a list comprehension. In fact, it seems like
    Chris> a darn good idea! The fact that the current implimentation
    Chris> doesn't enforce it is a pretty poor design justification...or am
    Chris> I missing something?

    >> map() is like any other function written in C.  It does its thing,
    >> then returns.

    Chris> The fact that it is written in C should ideally not determine
    Chris> it's behaviour. Ideally the behavious or map(), and list
    Chris> comprehensions, should be determined by some sensible design
    Chris> criteria, including performance, of course.

This is not an ideal world.  The fact that map() is a function (defined in C
or Python makes no difference) determines that.  The mapping from the name
"str" to the function object that performs stringification takes place one
time only, when map()'s input parameters are evaluated.  As far as map() is
concerned the name of the function may as well be
"the_moon_is_made_of_green_cheese".

    >> >> But there is no guarantee that the list you are operating on isn't
    >> >> modified by another thread during execution.
    >> 
    Chris> but there should be !!
    >> 
    >> Why here and not elsewhere in the language?  

    Chris> I thought you said that map() doesn't allow it?

map() gets a snapshot at the time it's called.  The binding of the name
"str" can change during map()'s execution.  It just won't notice.  For loops
and list comprehensions reevaluate the name-to-object mapping each time
around the loop.  Let me see if I can cook up a simple example...  Okay,
toss this in a .py file and run it from the command line:

    def a(i):
        global c
        c = b
        return "a"

    def b(i):
        global c
        c = a
        return "b"

    def pymap(f, l):
        newl = []
        for elt in l:
            newl.append(f(elt))
        return newl

    n = 5

    c = a
    print "maploop:", pymap(c, range(n))

    c = a
    l = []
    for i in range(n):
        l.append(c(i))
    print "forloop:", l

    c = a
    print "lcloop:", [c(i) for i in range(n)]

and execute it.  You should see

    maploop: ['a', 'a', 'a', 'a', 'a']
    forloop: ['a', 'b', 'a', 'b', 'a']
    lcloop: ['a', 'b', 'a', 'b', 'a']

Note that I don't call the real builtin map(), but a pseudo-map written in
Python.  It still doesn't notice the change in binding of the name "c",
because what c referred to at the point it was called was bound to pymap's
formal parameter "f".  The same thing happens with the real map() or with
any other function.  In the for loop and list comprehension examples, c is
not a parameter, so they look it up each time around the loop.

    >> I'm afraid you're tilting at windmills.

    Chris> Perhaps I am. It may be that a highly dynamic language isn't well
    Chris> suited to multi-threading, but this stuff sounds pretty scary to
    Chris> me... I'll have to remember to be very careful with any
    Chris> multi-threaded code I write.

Python is as well-suited to multi-threading as any other scripting language
I'm at all familiar with.  Actually, this discussion we're having doesn't
really have anything to do with threads at all.  I suggested threads as a
way that object bindings could change during the execution of a chunk of
code, but the example above demonstrates it just as well without using
threads.

    >> One approach might be to propose that the array object be "brought
    >> into the fold" as a builtin object

    Chris> This is in PEP 209 (with NumPY arrays, whcih is much better that
    Chris> the library array). I'm looking forward to it, I wish I could do
    Chris> more to help out. Note that PEP 211 and 225 are relevent too. The
    Chris> three together would do a lot to make Python more
    Chris> "array-oriented" which I think would be wonderful.

I'm not familiar with PEP 209 (one can't read everything).  In scanning the
abstract it looks like the authors propose a redesign of Numeric, not
incorporation of Numeric into the language.  I was suggesting that perhaps
the array object could be elevated to the same status as lists, tuples and
dicts, with appropriate changes made to the virtual machine to take
advantage of arrays' homegeneity.  Moving array into the language would
probably be a lot more modest bit of work than moving Numeric into the
language.  Of course, if that step is to be taken, the array object could
probably benefit from experience with Numeric.

    >> and modifications be made to the virtual machine so that homogeneity
    >> can be assumed when operating on arrays.

    Chris> That would be a great next step.... it's not in the PEP yet,
    Chris> maybe I'll send a note to authors.

    Chris> further off. Personally, I think a little static type
    Chris> declarations could help Py2C and the like a lot.
    >> 
    >> Sure, but then it wouldn't be Python. ;-)

    Chris> I'm not so sure about that... be definintion any change or
    Chris> enhancement makes something that is not python. As long as full
    Chris> dynamic typing is the default, it would still be Python.

If I wrote a module in Python then compiled it to C, I would sure want it to
behave the same.  Otherwise, the compilation process would probably
introduce subtle bugs into the code.  I'd hate to have to debug the
generated C code.

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/

From MarkH at ActiveState.com  Mon Sep 10 04:01:22 2001
From: MarkH at ActiveState.com (Mark Hammond)
Date: Mon, 10 Sep 2001 08:01:22 GMT
Subject: pythoncom.lib: Where may I find it, please?
References: 
Message-ID: <3B9C741E.6050909@ActiveState.com>

Bill Bell wrote:

> 
You will need to visit starship.python.net/crew/mhammond.cvs.html, and build from the Pythoncom source code.

Mark.

From frederic.giacometti at arakne.com  Thu Sep 20 00:49:24 2001
From: frederic.giacometti at arakne.com (Frederic Giacometti)
Date: Thu, 20 Sep 2001 04:49:24 GMT
Subject: Embeded Multi-Threaded Python: PyEval_InitThread(), PyEval_SaveThread(),...
References:  <8e0ac4fb.0109191313.5fef1454@posting.google.com>
Message-ID: 

"Nicolas Duchastel"  wrote in message
news:8e0ac4fb.0109191313.5fef1454 at posting.google.com...
> Thanks for the quick response.... but.....
>
> I actually RTFM-ed it; that's why my question is so detailed.
CYSPE ?? (Translation: Can you speak English ?)
What is this funky RTFM verb ???

> The doc seem to be conflicting in some areas and lacks some important
> information.
>
> For example, Chapter 8 states that Py_Initialized() can be called
> before or after PyEval_InitThreads(); so which is best ? what are the
> implications ? any nuance between these two ways ? any examples ?

This is not conflicting, it just states the order dones not matter; which is
true.

What's missing in the documentation is the indication that
PyEval_InitThreads() creates and initialize the global lock; and thus must
have been called before any real thread operation is engaged.
The code of PyEval_InitThreads is only a couple of lines long. Looking at it
might help you, too.

> Also, chapter 8.1 does indicated 4 different ways to do locking:
>   C_Function_ToCallPythonCode()
>   {
> PyThreadState* save = PyEval_SaveThread(); // LOCK
> PyImport_ImportModule( ...); // load another module
> PyRun_SimpleString(...);      // execute a 1 line of Python code
> PyPObject_CallMethod(....); // execute a full Python method
> PyEval_RestoreThread(save); // UNLOCK

But they don't refer to the same locks.... For instance, there is a global
interpreter lock, and an import lock; these are two different locks.
So, yes, you're locking, but you're not locking the same thing.  Not all
locks are the same, you know :))

>   }
> OR
>   C_Function_ToCallPythonCode()
>   {
> PyEval_AcquireLock(); // LOCK
> PyImport_ImportModule( ...); // load another module
> PyRun_SimpleString(...);      // execute a 1 line of Python code
> PyPObject_CallMethod(....); // execute a full Python method
> PyEval_ReleaseLock(); // UNLOCK
>   }
> OR
>   C_Function_ToCallPythonCode()
>   {
> PyEval_AcquireThread(??); // LOCK
> PyImport_ImportModule( ...); // load another module
> PyRun_SimpleString(...);      // execute a 1 line of Python code
> PyPObject_CallMethod(....); // execute a full Python method
> PyEval_ReleaseThread(??); // UNLOCK

There are two global interpreter lock/thread function/macro sets: one which
is source-compatible with single-threaded Python builds, and another one
which is not.

In addition to this, PyEval_InitThread() does some acrobaties to dynamically
enable/disable thread on python extension modules, so that the same module
can work on mutli-threaded and single-threaded python engine; non of this
being actually documented, of course :))

As resultat des courses, when you invoke binary extensions from the 'python'
command, the PyEval_InitThread() is only executed upon loading a module
requiring threads (e.g. the threads module).
If you create your own binary module which might work on its own thread,
you'll also want to insert a PyEval_InitThread() call in the module
initialisation function.

Voila...

>   }
> OR
>   C_Function_ToCallPythonCode()
>   {
> Py_BEGIN_ALLOW_THREADS
> PyImport_ImportModule( ...); // load another module
> PyRun_SimpleString(...);      // execute a 1 line of Python code
> PyPObject_CallMethod(....); // execute a full Python method
> Py_END_ALLOW_THREADS
>   }
>
> So which one should I use ?

You should use the macros, preferably to explicit function calls, whenever
you can...

> Also, image my 2 distinct thread B and C executing the 1st snipplet of
> code above, if the call to PyObject_CallMethod() is VERY long and
> takes ages,...

Python takes care of it, don't worry :)))

> chapter 8 says
>
>    "In order to support multi-threaded Python programs, the
>     interpreter regularly releases and reacquires the lock --
>     by default, every ten bytecode instructions."
>
> Does that thus mean that a 2nd thread running this 1st snipplet
> above will be interupted in the middle of its work in
> PyObject_CallMethod() and another thread will have a go at it.

That's what thread switching is about, doesn't it ?

> If so, what happens to the ThreadState object when the 2nd thread
> calls PyEval_SaveThread() ? if it doesn't swap it, it will run with
> the 1st thread's ThreadState object. If it does swap it, when this
> 2nd thread will also get interupted, won't the 1st thread get back
> to run and thus it will run with the 2nd thread's object !?
> I mean, I must be missing someting !?

No (or maybe a little imagination :)): Just think of the Python virtual
machine as a single process ressource shared between the native threads.

> Also, what about the things I was asking with regards to the actual OS
> thread's ID ? i.e. does it matter that my code starts in one thread
> and then works from another thread ? do I need to create ThreadState
> objects for each threads ?

?????

> Thus,.. please RTFP (where P is for Posting rather than Manual)

Qu'es aqueo ????

>
> Thanks,

De rien.

> Nicolas

FG

From fredp at mygale.org.nospam  Tue Sep  4 12:41:30 2001
From: fredp at mygale.org.nospam (Fred Pacquier)
Date: 4 Sep 2001 16:41:30 GMT
Subject: (beginner) question on threads...
References:    <3B928478.6DE44401@earthlink.net>  <3B9456D0.635BDC3E@student.gu.edu.au>
Message-ID: 

Joal Heagney  said :

> *chuckles* You'll find this is THE best newsgroup to ask naive
> questions in. The gurus (Tim, Emile and Guido to name a few) don't mind
> answering the really interesting questions (Implementation, exotic
> classes etc.) people pop up, the intermediates take this as an example
> of good behaviour and take care of the medium level questions and then
> people like me answer as many newbie questions that they can accuratly
> field. The trick is to know when to shut up and let somebody more
> experienced field the question. Plus each of us at the just-above
> neophyte level has experience in different aspects of python, and how
> we learnt it - I know some of the beginner-useful modules (not all) and
> I'm very good at how to build python and python extension module rpms.

Yup -- that is definitely a huge part of the global python picture. There 
is the language itself and its own merits, and then there are the sorts of 
people who tend to gather around it, push it in various directions, and 
form its distinctive community. Don't know which way the chicken-and-egg 
aspect really works, but python certainly wouldn't be where it is without 
both...

> If you look at the standard library, you'll see one of the major
> principles of python coding is to keep the inheritance tree as flat as
> possible. For example, you have a module A, that imports module B,
> which imports module C. Now module A uses a function in module B that
> comes from module C. It is better code practice to import module C into
> module A and use the function directly, rather than rely on it being
> included in module B.

Well, in my own code I certainly take care to keep things at the simplicity 
level I feel I can handle :-)
But in this particular case, I was nosing through the standard lib's 
*HTTPServer modules, where classes are effectively nested a few levels 
deep.

>> Is there not a better way ? Some tool that will build a picture of a
>> class from its code, with all its methods and attributes, inherited or
>> not ? 
> 
> from pydoc import help
> import os
> help(os)
> class test:
>      def __init__(self,blah):
>           self.blah = blah
>      def afunc(self,values):
>           blahblablah
> class test2(test):
>      def bfunc(self):
>           blah-blablabla - blabblah
> help(test)
> And then the pydoc module supports other objects that let you build
> html/txt and output to file.

Aha. This is new in 2.x, right ? Need to look into that. Thanks for the tip 
and encouragement !
fp

-- 
YAFAP : http://www.multimania.com/fredp/

From joek at quantiva.com  Wed Sep  5 13:38:19 2001
From: joek at quantiva.com (Joe Kelly)
Date: 5 Sep 2001 10:38:19 -0700
Subject: Building gdmodule-0.23 under Python2.1.1
Message-ID: 

I am trying to build gdmodule.so into Python2.1.1. And it is failing.

Has anyone done this successfully?

It builds correctly, but when I try to import gd I get:
10026>mach(joek)$ python
Python 2.1.1 (#1, Aug 31 2001, 20:46:16)
[GCC 2.95.2 19991024 (release)] on sunos5
Type "copyright", "credits" or "license" for more information.
>>> import gd
Traceback (most recent call last):
  File "", line 1, in ?
ImportError: ld.so.1: python: fatal: relocation error: file
./gdmodule.so: symbol gdImageCreateFromJpeg: referenced symbol not
found
>>>

I build gdmodule.so via:
gcc -fPIC -g -O2 -Wall -Wstrict-prototypes
-I/home/joek/build/python/pkg/python/reloc/include/python2.1
-I/home/joek/build/python/pkg/python/reloc/include/python2.1
-DHAVE_CONFIG_H  -I./install/include -c ././gdmodule.c -o ./gdmodule.o

ld -G  ./gdmodule.o  -L./install/lib -L/usr/lib/X11 -L/usr/X11R6/lib
-lgd -lz -lpng -ljpeg -lttf -lX11 -lXpm  -o ./gdmodule.so

Libgd.a should have the gdImageCreateFromJpeg:
It is in gd_jpeg.c:
gcc -I. -I/home/joek/build/gd/gd-1.8.3/../current/install/include -O 
-c  gd_jpeg.c

ar rc libgd.a gd.o gd_gd.o gd_gd2.o gd_io.o gd_io_dp.o \
        gd_io_file.o gd_ss.o gd_io_ss.o gd_png.o gd_jpeg.o gdxpm.o \
        gdfontt.o gdfonts.o gdfontmb.o gdfontl.o gdfontg.o \
        gdtables.o gdttf.o gdcache.o gdkanji.o wbmp.o gd_wbmp.o
ranlib libgd.a

We have successfully built it with Python1.5.2, but not with
Python2.1.1.

The platform is Solaris on Intel.
SunOS mach 5.8 Generic_108529-03 i86pc i386 i86pc

Any help would be greatly appreciated.

From tanzer at swing.co.at  Mon Sep 10 03:00:27 2001
From: tanzer at swing.co.at (Christian Tanzer)
Date: Mon, 10 Sep 2001 09:00:27 +0200
Subject: text processing: variable interpolation and more 
In-Reply-To: Your message of "Sun, 09 Sep 2001 17:17:29 -0000."
             <1000055849.582487@cswreg.cos.agilent.com> 
Message-ID: 

weeks at vitus.scs.agilent.com (Greg Weeks) wrote:

> Oleg Broytmann (phd at phd.pp.ru) wrote:
> : print "Dear %(recipient)s:" % dict  ...
> 
> :    will extract dict[recipient] and put it into the string as string. More
> : details in Python docs about overloaded operator %.
> 
> Thanks.  I (obviously) was only aware of (s % d) with d a tuple, despite
> the fact that my textbook describes both cases in the same sentence.  Oops!
> 
> Still, with *two* dictionaries you can capture the entire scope.  Or,
> rather, you could in 1.5.2.

You might want to try something like this:

class Scope :
    """Capture global and local variables visible in caller's scope.

       The index operator also supports expressions as indices and will
       return the result of such expressions as evaluated in the caller's
       scope.

       The supplied index operator allows Scope objects to be used as
       mapping arguments for the string formatting operator `%s':

       >>> "42*3 == %(42*3)d" % Scope ()
       '42*3 == 126'
    """

    def __init__ (self, globals = {}, locals = {}) :
        self.globals = globals
        self.locals  = locals 
    # end def __init__

    def __getitem__ (self, index) :
        return eval (index, self.globals, self.locals)
    # end def __getitem__

With some black magic you can make Scope pick up the caller's global
and local variables all by itself.

-- 
Christian Tanzer                                         tanzer at swing.co.at
Glasauergasse 32                                       Tel: +43 1 876 62 36
A-1130 Vienna, Austria                                 Fax: +43 1 877 66 92

From mlh at idi.ntnu.no  Mon Sep 24 15:24:15 2001
From: mlh at idi.ntnu.no (Magnus Lie Hetland)
Date: Mon, 24 Sep 2001 21:24:15 +0200
Subject: To re or not to re ... ( word wrap function?)
References:  
Message-ID: <9oo18v$f22$1@tyfon.itea.ntnu.no>

"Chris Barker"  wrote in message
news:mailman.1001355746.18274.python-list at python.org...
> Thanks to all of you who posted code: I've learned something from each
> one.
>
>
> I did notice that no one used an re-based solution, except Skip using
>
> re.split(r'\s+', s)
>
> Is this any different than string.split(s) ?

Not that I can see.

> Note that I didn't want to use either of these, as they would kill any
> sequences of whitespace, such as two spaces after a sentence.

Well -- you're not supposed to have that, are you? 

(A bit larger than a single space when typeset, sure -- but two
spaces in text? Yuck...)

So, you basically want to keep your whitespace? Then wrappint will
be hard... What whitespace will you allow to be changed into
a newline, for instance?

> tex_wrap looks very nice but is really overkill for this application.
>
>
> I also noticed that no one took my approach, which was to start at the
> end of the line and work backwards looking for space. You all took the
> approach of building the new line word by word from the beginning.

I'm sure that's a nice approach -- but how do you avoid ending up with
a short first line? (A short last line is OK.)

> hmmmm.
>
> -Chris

--

  Magnus Lie Hetland         http://www.hetland.org

 "Reality is that which, when you stop believing in
  it, doesn't go away."           -- Philip K. Dick

From loewis at informatik.hu-berlin.de  Tue Sep  4 05:25:09 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 04 Sep 2001 11:25:09 +0200
Subject: COM/CORBA/DCOP (was: Hello people. I have some questions)
References:  <9mu5si$9gg$1@pea.uk.research.att.com>
Message-ID: 

Duncan Grisby  writes:

> There's nothing inherently slow about C++ ORBs. MICO was never
> designed for performance -- indeed its stated design goal is code
> clarity and wide feature range at the expense of performance. Why the
> KDE people didn't pick one of the better-performing C++ ORBs, I don't
> know.

I've heard various stories of why KDE stopped using CORBA; it being
too slow was just one reason. Other reported problems are:
- all client-server interaction was across address spaces, ie. there
  was no good support for in-process servers.
- when a client broke down, it was difficult to garbage-collect the
  servers, so they had many stray processes.
- it was perceived as being difficult to use by application developers.
  IMO, this was partially due to KDE offering wrapper libraries around
  common interfaces, for convenience. Thus, and application developer
  had many different ways to achieve the same effect, due to the layers
  of wrappers.

Regards,
Martin

From pmoscatt at bigpond.net.au  Tue Sep 11 04:32:14 2001
From: pmoscatt at bigpond.net.au (Peter Moscatt)
Date: Tue, 11 Sep 2001 08:32:14 GMT
Subject: Reading Variables From Modules ?
Message-ID: 

I have a simple question - well to some I hope :-)

If I was to have a module named MyModule.py which had a function like:

        def TestNumber():
                A = 10
                return

And I was importing this module into MyMain.py and then wanted to test the 
value of A in the imported module like:

        import MyModule
        if MyModule.A > 10 dosomething

Obviously this dosen't work, so how is the best way to test the value of 
'A' in the imported module ?

Regards
Pete

From aleax at aleax.it  Tue Sep  4 04:07:53 2001
From: aleax at aleax.it (Alex Martelli)
Date: Tue, 4 Sep 2001 10:07:53 +0200
Subject: Conditional operator in Python?
References: <3AC68CB8.22AAF7B8@alcyone.com> <9a631k$3s8qb$1@ID-11957.news.dfncis.de>  <3AC6BB2E.1E09B5AA@alcyone.com>  <9n1hr7$7op$1@glue.ucr.edu> <3B947E32.C5604328@el_simpatico.be>
Message-ID: <9n224q01dfe@enews3.newsguy.com>

"Weet Vanniks"  wrote in message
news:3B947E32.C5604328 at el_simpatico.be...
> What about :
>
> def cond_choose(cond,first_choice,second_choice):
>      if cond:
>           return first_choice
>      return second_choice
>
> whatever= cond_choose(x,a,b)
>
> This seems much cleaner to me than all those contorsions with the syntax.

It is, but it has entirely different semantics: BOTH a
and b are FULLY evaluated BEFORE one of them is chosen.

This is totally inappropriate for many uses of 'choice',
such as guarding against incorrect operations, controlling
recursion, and so on.

E.g.:

    result = cond_choose(x, 23/x, 149)

this tries to compute 23/x even when x is zero.  This is NOT
the correct semantics for conditional-choice.  Any of
the alternative approaches, such as:
    result = (x and 23/x) or 149
WILL behave correctly: since and/or "short-circuit", the
right-hand-side operand is *NOT* evaluated -- the division
by zero will not happen with this coding.

Alex

From thp at cs.ucr.edu  Wed Sep 19 17:02:59 2001
From: thp at cs.ucr.edu (thp at cs.ucr.edu)
Date: Wed, 19 Sep 2001 21:02:59 +0000 (UTC)
Subject: Proposed PEP for a Conditional Expression
References: 
Message-ID: <9ob163$a0v$1@glue.ucr.edu>

James_Althoff at i2.com wrote:

: Tom Payne wrote:
:>I have a similar objection to the syntax:
:>
:>        cond( , lambda:, lambda: )
:>
:>Moreover it doesn't scale up to multiple tests very well:
:>
:> cond( , lambda:, lambda:cond( , lambda:, lambda:
: ) )
:>
:>or stacked/indented version thereof.

: ... which is perhaps mitigated by the fact that nested conditional
: expressions is probably not a great idea for readability in any case.

To me,

          count = 1 if by_land() else
                  2 if by_sea()  else
                  0

is clearer than

         if by_land():
                 count = 1
         elif by_sea():
                 count = 2
         else:
                 count = 0

By contrast, 

         count = cond( by_land(), lambda: 1,
                 cond( by_sea(),  lambda: 2,
                                  lambda: 0
                 ))

is indeed "not a great idea for readability."

Tom Payne

From phd at phd.pp.ru  Mon Sep  3 05:58:17 2001
From: phd at phd.pp.ru (Oleg Broytmann)
Date: Mon, 3 Sep 2001 13:58:17 +0400 (MSD)
Subject: cgi type=file problems
In-Reply-To: 
Message-ID: 

On 3 Sep 2001, Dag wrote:
D> I have a HTML form with a type=file input element and I simply want to
D> get the file name as a string.  I'm not interested in the actual file.
D> However the value from the file part of the form doesn't seem to get
D> passed at all.
D> For example I have the following form and script;
D>
D> 

Oleg.
----
     Oleg Broytmann            http://phd.pp.ru/            phd at phd.pp.ru
           Programmers don't die, they just GOSUB without RETURN.

From dale at riverhall.NOSPAMco.uk  Thu Sep 13 09:59:54 2001
From: dale at riverhall.NOSPAMco.uk (Dale Strickland-Clark)
Date: Thu, 13 Sep 2001 14:59:54 +0100
Subject: XML confusion
References: <0be1qt8qon2mjb9dj2s94po54gi6h7gt9q@4ax.com>
Message-ID: 

Dale Strickland-Clark  wrote:

>I'm reading what I can find on XML with Python and came upon this:
>
>
>http://py-howto.sourceforge.net/xml-howto/node14.html
>
>The first paragraph makes reasonable sense but it goes sharply down
>hill after that.
>
>Does that look like Java definitions?

I think I've figured it out.

The doc's not finished. Not by a long way.

>From the next section onwards, it's just headings.

Work in progress or abandoned? Either way, not much point in putting
it online in this condition.
--
Dale Strickland-Clark
Riverhall Systems Ltd

From pinard at iro.umontreal.ca  Wed Sep  5 18:44:12 2001
From: pinard at iro.umontreal.ca (=?iso-8859-1?q?Fran=E7ois?= Pinard)
Date: 05 Sep 2001 18:44:12 -0400
Subject: pymacs! :-)
In-Reply-To: <9n5pch$806$1@animus.fel.iae.nl>
References: 
	<9n5pch$806$1@animus.fel.iae.nl>
Message-ID: 

[Carel Fellinger]

> Like Marcin, I would prefer a lisp.fun notation.  And as many lisp names
> use funny characters like -, I suggest adding a [] interface as well,
> so we easily can access those weird emacs names like in

>    count = lisp["1+"](count)

Hello, Carel, and others.  Let me thank you, as well as those who wrote
various suggestions to me.  I tried to take good care of all ideas. :-)

Yes, I exactly added this (using square brackets) earlier today.  Calling
functions as per above was already in place since one day or two.  Also,
`lisp' itself can be used as a function to execute raw LISP code, like this:

     value = lisp("""
       ...
       POSSIBLY LONG LISP EXPRESSION
       ...
     """)

There is another interesting feature I put in today.  Consider:

     def procedure(object):
        lisp.setcdr(object, 17)

presuming that `object' has been given a cons-cell.  I wanted the `setcdr'
to act on the original OBJECT, and not on a copy.  So, `object' is a handle
to the LISP argument right in LISP space, whenever that argument is mutable.
A slight difficulty, easily solved, was to make sure those handles are
freed in LISP space in proper time, so they can be garbage collected.

On the debugging side, Python exceptions are properly reported as
tracebacks on the LISP side, while LISP errors occurring while Emacs is
serving Python are more summarily reported to Python and back to LISP.
This should not have adverse effects on later computations (I hope I did
it right).  One may add `print' debugging statements in Python, and with
a minimum of care, these will correctly appear in the `*Pymacs*' window.

Some handles could usefully be seen as sequences, I'll explore this.
Also, given handles and symbols have a `.value()' method, I'm thinking
of adding a `.copy()' method for handles, that would return an expanded
copy of the list as usable as possible on the mere Python side, without
further communication.  LISP proper lists could become Python tuples, LISP
vectors could become Python lists, and strings might loose their properties.

On summary, that project goes well, is nearly usable, and still small:
pymacs.el is 268 lines, pymacs.py 262 lines, and pymacs-services 11 lines.
The growth may be explained by the fact I added some documentation! :-)

-- 
Fran?ois Pinard   http://www.iro.umontreal.ca/~pinard

From Weet.Vanniks at el_simpatico.be  Tue Sep  4 06:57:55 2001
From: Weet.Vanniks at el_simpatico.be (Weet Vanniks)
Date: Tue, 04 Sep 2001 12:57:55 +0200
Subject: Conditional operator in Python?
References: <3AC68CB8.22AAF7B8@alcyone.com> <9a631k$3s8qb$1@ID-11957.news.dfncis.de>  <3AC6BB2E.1E09B5AA@alcyone.com>  <9n1hr7$7op$1@glue.ucr.edu> <3B947E32.C5604328@el_simpatico.be> 
Message-ID: <3B94B3B3.6775EE3C@el_simpatico.be>

Your counter-example seems contorted to me.
I would never use:
    whatever = cond_choose(cond, format_disk(), leave_it_as_is())
for the mere reason that I have been taught that:
    1. when there is room for confusion, people get confused
    2. arguments in a function call should NEVER have side-effects.
    3. obfuscated one-liners with lambda functions bring more confusion
than anything else
        (the alledged efficiency is still to be demonstrated as you
correctly state)
    4. The spirit of Python is : "If it ain't obvious, it ain't Python"
and contorted syntax does not help support that spirit

Weet

Fredrik Lundh wrote:

> Weet Vanniks wrote:
> > What about :
> >
> > def cond_choose(cond,first_choice,second_choice):
> >      if cond:
> >           return first_choice
> >      return second_choice
> >
> > whatever= cond_choose(x,a,b)
>
> well, compare
>
> whatever = cond_choose(cond, format_disk(), leave_it_as_is())
>
> with
>
>     if cond:
>         whatever = format_disk()
>     else:
>         whatever = leave_it_as_is()
>
> > This seems much cleaner to me than all those contorsions with
> > the syntax.
>
> of course, the best way to avoid those contorsions is to fix the
> Return and Tab keys on your keyboard, and learn how and when
> to use them...
>
> (it also helps to know that lambdas and list constructors are
> expensive, and assignments to temporary locals are cheap.
> And contrary to common belief, the Python interpreter can
> skip over linefeeds in almost no time at all...)
>
> 

From slinkp23 at yahoo.com  Wed Sep 12 11:46:03 2001
From: slinkp23 at yahoo.com (Paul Winkler)
Date: Wed, 12 Sep 2001 15:46:03 GMT
Subject: Performance of list comprehensions vs. map
References: <3B966B1C.120D0AF6@home.net>  <9n7n6u02leo@enews1.newsguy.com>  
Message-ID: 

On 7 Sep 2001 20:49:29 GMT, Marcin 'Qrczak' Kowalczyk  wrote:
>Fri, 07 Sep 2001 20:17:12 GMT, Paul Winkler  pisze:
>
>> So for the foreseeable future, looks like map() is likely to remain
>> the fastest way to generate lists.
>
>As long as the function to map is ready. If a separate function must
>be created just for mapping (doesn't matter id by 'def' or 'lambda'),
>I would expect a list comprehension with the function's body inserted
>to be faster than map which must call it.

Interesting idea. I just tried ...  Yes, *if* what you're doing is
practical to inline in the list comprehension, that can beat map().
And of course if what you're doing is calling, say, a function or
method from the standard library, you're not going to inline that, so
map() still looks like a good idea.

Example:

test = xrange(100000)

def multiplier(x):
    return x * 0.99

def mapper(m=multiplier, f=test):
    return map(m, f)

def comprehender_inline(f=test):
    return [x * 0.99 for x in f]

def comprehender(m=multiplier, f=test):
    return [m(x) for x in f]

# end of example

In this case, comprehender_inline wins by a very large margin,
followed by mapper, which is in turn faster than comprehender.

But here's the counterexample:

import string
test = # a 100000-character random string

def mapper(m=string.upper, f=test):
    return map(m, f)

def comprehender(m=string.upper, f=test):
    return [m(x) for x in f]

su = string.upper
def comprehender_inline(f=test):
    su = string.upper
    return[su(x) for x in f]

# end example

In this case, comprehender_inline is about the same speed as
comprehender, no surprise since they're almost identical. Map wins by
a large margin. If you rewrite comprehender_inline so it returns
[x.upper() for x in f], it speeds up quite a lot, but still loses to
map, and we're not really comparing apples to apples anymore.

From tim.one at home.com  Sat Sep  1 18:11:44 2001
From: tim.one at home.com (Tim Peters)
Date: Sat, 1 Sep 2001 18:11:44 -0400
Subject: Stackless Python and Python 2.x
In-Reply-To: <3B90468D.E64ECCB7@student.gu.edu.au>
Message-ID: 

[Joal Heagney]
> Wasn't a big part of the generator addition that it supplies a
> simpler-to-understand solution to the majority of continuations
> solutions?

I expect that if you dug into all the applications using Stackless, you'd
find that the majority of them rely on full-blown coroutines or
microthreads.  It's unclear how far PEP 255's "Simple Generators" can be
pushed towards those specific ends.

Neil Schemenauer discovered that it was possible to code the "traditional"
coroutine examples using simple generators instead, and being able to
explicitly resume a generator object independent of magical control context
was key to that (an ability Icon generators and CLU iterators don't have, so
the limitations of the latter don't necessarily apply to Python's flavor of
the idea too).

But it remains unclear how far that can be pushed.  In any case, it wasn't
PEP 255's intent to kill off Stackless, but to get at many things you *can*
do with continuations for which continuations aren't *necessary*.  The
implementation changes needed to support simple generators were minor by any
measure, and the Jython folks believe it's doable on top of the JVM too.  In
bang for the buck, they're a big win, but it's not clear they reach Big Bang
status.

but-creating-a-new-universe-wasn't-their-goal-ly y'rs  - tim

From ht_xu at hotrmail.com  Mon Sep 10 18:09:41 2001
From: ht_xu at hotrmail.com (Henry)
Date: Mon, 10 Sep 2001 17:09:41 -0500
Subject: How to know it is a list?
References: 
Message-ID: 

Thank you all guys, your help is highly appreciated.

Henry

"Henry"  wrote in message
news:jw9n7.6109$Ku4.124514 at e420r-atl2.usenetserver.com...
> Hi guys,
>   I have a newbie question. How do check if a variable is a list?
>
> Thanks in advance,
> Henry
>
>
>

From strnbrg at c532352-a.frmt1.sfba.home.com  Tue Sep 25 12:27:00 2001
From: strnbrg at c532352-a.frmt1.sfba.home.com (Theodore D. Sternberg)
Date: Tue, 25 Sep 2001 16:27:00 GMT
Subject: widget['command']
Message-ID: 

How do you obtain a reference to a Tkinter widget's callback?  widget['command']
only gives me a munged version of the callback's name.  Of course what I'd like
is a reference to a real function that I can use in "apply".  

Ted Sternberg
Berkeley, California USA

From ignacio at openservices.net  Mon Sep 17 16:49:29 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Mon, 17 Sep 2001 16:49:29 -0400 (EDT)
Subject: Newbie: How to download a JPG file from the internet....?
In-Reply-To: 
Message-ID: 

On Mon, 17 Sep 2001, John Branthoover wrote:

> Hello All,
>     Can anyone tell me how to download an image from a web site?
> An example:
>  that is located at www.somewhere.org
>
>     I have already found the urllib module and have used the urlopen
> function to create a string from a web page,  but I don't know how to
> proceed from here.  I can isolate the string -   SRC="./images/getme.jpg">, but then what?  I would like to eventually write
> it to a file on my local drive.  Any information will be greatly
> appreciated.  Thank you for your time.

The first thing you have to do is get the value of the src attribute from the
img tag.

Once you have that, you have to determine if it's an absolute or relative URL.
If it's absolute, then you just get it and write it to a file. If it's
relative, then you have to parse the document for a base tag and apply
the relative URL to that to get an absolute URL.

If there is no base tag, then you have to apply the relative URL to the
absolute URL of the page you are downloading and go from there.

-- 
Ignacio Vazquez-Abrams  

From chrishbarker at home.net  Wed Sep 12 14:19:33 2001
From: chrishbarker at home.net (Chris Barker)
Date: Wed, 12 Sep 2001 11:19:33 -0700
Subject: PEP proposal for round(x,n) enhancement
References:  
Message-ID: <3B9FA735.7319C83@home.net>

Christopher Smith wrote:

> There should be away to say "round to the 3rd digit from the first
> non-zero digit.

Absolutely.

> I have checked both the Scientific and Numeric packages.  While they do
> allow for extended sorts of formatting (like Fortran formats, etc...) I do
> not see this sort of functionality built into them.

I suggest you post to the NumPy list about this, for two reasons:

1) There are some sharp people there that could help you come up with a
robust algorithm

2) It would be a whole lot easier to get this added to NumPy or SciPy as
a Ufunc than it will be to get it into Python itself (not that it
shouldn't be there, it should). In fact, you could wite it yourself for
NumPy...

By the way, SciPy is a different and more ambitious project than
Scientific. Check out:

www.scipy.org.

-Chris

-- 
Christopher Barker,
Ph.D.                                                           
ChrisHBarker at home.net                 ---           ---           ---
http://members.home.net/barkerlohmann ---@@       -----@@       -----@@
                                   ------@@@     ------@@@     ------@@@
Oil Spill Modeling                ------   @    ------   @   ------   @
Water Resources Engineering       -------      ---------     --------    
Coastal and Fluvial Hydrodynamics --------------------------------------
------------------------------------------------------------------------

From andy_todd at spam.free.yahoo.com  Sun Sep 23 23:16:27 2001
From: andy_todd at spam.free.yahoo.com (Andy Todd)
Date: 24 Sep 2001 03:16:27 GMT
Subject: time.timezone gives strange results on cygwin
Message-ID: 

time.timezone is returning an incorrect value on cygwin python.

Whilst running some code on different platforms I have identified what I 
believe to be a bug in the timezone function of the time module on cygwin.
This works as expected from Windows (Python 2.1.1 on Win2k, Win98, WinNT4) 
but on the same machines via cygwin comes up with an incorrect figure.

>From the documentation;

"""
timezone 
     The offset of the local (non-DST) timezone, in seconds west of UTC
     (i.e. negative in most of Western Europe, positive in the US, zero in 
     the UK). 
"""

The timezone set on all of my machines is AEST - Australian Eastern 
Standard Time which is 10 hours ahead of UTC. 
>From windows;

>>> import time

>>> print time.tzname

('AUS Eastern Standard Time', 'AUS Eastern Daylight Time')

>>> print time.timezone

-36000

But from cygwin on the same machine;

$ python
Python 2.1.1 (#2, Aug 23 2001, 10:41:44)
[GCC 2.95.3-5 (cygwin special)] on cygwin
Type "copyright", "credits" or "license" for more information.
>>> import time
>>> print time.tzname
('AUSEST', 'AUSEDT')
>>> print time.timezone
1834228892
>>>

Any suggestions? I'm presuming that the underlying system function that is 
called to calculate the timezone offset is wrong under cygwin.

Regards,
Andy
-- 
Content free posts a speciality

From skip at pobox.com  Fri Sep  7 17:42:42 2001
From: skip at pobox.com (Skip Montanaro)
Date: Fri, 7 Sep 2001 16:42:42 -0500
Subject: Performance of list comprehensions vs. map
In-Reply-To: 
References: <15257.12041.140352.873520@beluga.mojam.com>

Message-ID: <15257.16210.751461.185017@beluga.mojam.com>

    Tim> func_code has been writable for some time.  Here under 2.2a3:

Whoops!  Thanks for the correction.  I'm still working from a 1.5.2 codebase
in the rattlesnake stuff.  That's the only context in which I've ever wanted
to modify a function's code object, and, lo and behold, it's possible there
as well...

Skip

From markus at schabi.de  Wed Sep 26 11:53:54 2001
From: markus at schabi.de (Markus Schaber)
Date: Wed, 26 Sep 2001 17:53:54 +0200
Subject: importing symbols from module objects
References: <7xd74eephr.fsf_-_@ruckus.brouhaha.com> <3BB1681D.762AA451@home.com> <7xwv2mik2i.fsf@ruckus.brouhaha.com> <3BB1DE64.E84241F0@engcorp.com>
Message-ID: <1930273.Pv6tv2OnDr@lunix.schabi.de>

Hi,

Peter Hansen  schrub:

>> Hey, that ought to work.  I'm the one that missed something.  I'm not
>> totally used to this exceptions=classes=instances stuff yet.  Now I
>> have to wonder what "from foo import bar as parrot" really does.
>> Maybe pretty much the same thing.  Anyway, thanks, I'll give it a
>> try.
> 
> It does this:
> 
> from foo import bar
> parrot = bar
> del bar

Is this really true?

With a.py containing:

def f():
  print "hello"

I did the following in python 2.0.1 interactive mode:
>>> a = 1
>>> f = 2
>>> from a import f as x
>>> print a,f,x
1 2 

Given your definition, f would be overwritten with the function and 
then deleted, thus not be bound to 2 any more.

markus
-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From slinkp23 at yahoo.com  Fri Sep  7 16:17:12 2001
From: slinkp23 at yahoo.com (Paul Winkler)
Date: Fri, 07 Sep 2001 20:17:12 GMT
Subject: Performance of list comprehensions vs. map
References: <3B966B1C.120D0AF6@home.net>  <9n7n6u02leo@enews1.newsguy.com>
Message-ID: 

On Thu, 6 Sep 2001 13:38:07 +0200, Alex Martelli  wrote

(snip - a very long and detailed discussion of map, list
comprehensions, and for/append loops)

Thanks very much, Alex, now I understand what's happening under the
covers! I guess that optimizing list comprehensions in this way is
probably not worth the trouble, given the factors you mention.  The
optional "if" clause of list comprehensions also complicates things.

I tried your test script, and got comparable results to yours, with
the exception that on my machine, use_map always beats pre_alloc even
when len() is "wrong" (although not by much). I tried it with
n=1000*1000 and n = 100 * 100 and got similarly proportioned results.

So for the foreseeable future, looks like map() is likely to remain
the fastest way to generate lists.

-- Paul Winkler

From dyoo at hkn.eecs.berkeley.edu  Sun Sep  9 15:24:13 2001
From: dyoo at hkn.eecs.berkeley.edu (Daniel Yoo)
Date: Sun, 9 Sep 2001 19:24:13 +0000 (UTC)
Subject: Cookie example?
References: 
Message-ID: <9ngfkt$1l5q$3@agate.berkeley.edu>

Tyler Eaves  wrote:

: Anyone have some code that reads and sets cookies using the cookie
: module?

I have a silly example of one here:

    http://hkn.eecs.berkeley.edu/~dyoo/python/cookiecounter.py

If you haven't seen it already, you might want to browse Useless Python:

    http://www.lowerstandard.com/python/

which isn't quite organized yet, but might have some examples you can
play with.  Also, the Vaults of Parnassus:

    http://www.vex.net/parnassus/

is a good resource for examples (although it appears to be down at the
moment... *sob*)

From scott at swiftview.com  Fri Sep  7 12:20:00 2001
From: scott at swiftview.com (Scott Long)
Date: Fri, 07 Sep 2001 09:20:00 -0700
Subject: Nested scopes: why is it weird?
Message-ID: <3B98F3B0.53AC2524@swiftview.com>

Nested scopes seem like a nice addition (of course!) but there are some
weird things about it. Take a look:

>>> from __future__ import nested_scopes
>>> def a():
...   def b():
...     k = x
...     print k
...   x = 1
...   b()
...
>>> a()
1

Right, this is what you would expect. But how about this?

>>> from __future__ import nested_scopes
>>> def a():
...   def b():
...     k = x
...     x = 0
...     print k
...   x = 1
...   b()
...
>>> a()
Traceback (most recent call last):
  File "", line 1, in ?
  File "", line 7, in a
  File "", line 3, in b
UnboundLocalError: local variable 'x' referenced before assignment

Here is my explanation for this (tell me if I'm wrong):

During pass #1 of compilation, the statement "x = 0" in b() binds x as a
local variable local to b(). During execution, k = x executes *before* x
has been assigned, resulting in this flamage.

My first beef here is, why is the exception called UnboundLocalError?
The variable is certainly bound (into the local scope), it simply has
not been assigned. Why not call it UninitializedLocalError? I know it
isn't going to change, I'm just asking.

But my main concern is that this way of selecting a binding seems very
unintuitive. Shouldn't the first statement referencing x be the
statement that specifies the binding of x? In this case, shouldn't "k =
x" cause x to get bound as a free variable, not a local to b()? I'm not
claiming that this is a bug. I am curious as to why it was decided that
things are going to work this way. It makes assignment to a variable in
an enclosing scope impossible!

Regards,
Scott

From wilson at netvmg.com  Tue Sep 18 17:27:12 2001
From: wilson at netvmg.com (Wilson Yeung)
Date: 18 Sep 2001 14:27:12 -0700
Subject: shelve vs pickle
References: <9ntpa2+uprc@eGroups.com>  <9nu72c.3vv2ert.1@kserver.org> <3BA65739.5301558@astro.cornell.edu>
Message-ID: 

I've had good results with the Sleepycat/Berkeley DB via the
Python interface pybsddb as my underlying store, together with
the pickle module.

Wilson

From nhodgson at bigpond.net.au  Tue Sep  4 20:34:38 2001
From: nhodgson at bigpond.net.au (Neil Hodgson)
Date: Wed, 05 Sep 2001 00:34:38 GMT
Subject: COM/CORBA/DCOP (was: Hello people. I have some questions)
References:  <9mu5si$9gg$1@pea.uk.research.att.com> <9mvkvr01db@enews2.newsguy.com> <7xelpo86rj.fsf@ruckus.brouhaha.com> <9n2q3b0d92@enews3.newsguy.com>
Message-ID: 

Alex Martelli:
[about Automation]
> ..., it's mostly about marshaling
> the arguments (they DO have to be marshaled, since the Invoke call
> of the IDispatch interface cannot accept "a generic stack frame" --
> it wants an array of VARIANT's, so SOME code, typically somewhere
> in the OLE runtime, must be marshaling
>     stackframe->array of VARIANTs->stackframe
> and THAT is the part that normally dominates, except perhaps
> on argument-less methods using optimized non-interpretive custom
> marshaling for the purpose).

   At the risk of being pedantic (and with Alex, it is *such* a temptation
:-) ), you can write your automation code (both client and server) to deal
with VARIANTs directly. The cost in Automation is more that a well behaved
server is supposed to coerce arguments into the form it requires (int->real,
string->number and even dereferencing byref arguments are often done) and
this often requires a bunch of tests and translation code.

   Neil

From emile at fenx.com  Fri Sep 28 10:06:43 2001
From: emile at fenx.com (Emile van Sebille)
Date: Fri, 28 Sep 2001 07:06:43 -0700
Subject: Problem with os.system()
References: <3bb47fd9_8@news.newsgroups.com>
Message-ID: <9p20e5$fhh23$1@ID-11957.news.dfncis.de>

Well I don't see any bugs in it.  ;-))

--

Emile van Sebille
emile at fenx.com

---------
"Janos Blazi"  wrote in message
news:3bb47fd9_8 at news.newsgroups.com...
> I have the following code:
>
>
>
>
> -----=  Posted via Newsfeeds.Com, Uncensored Usenet News  =-----
> http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
>  Check out our new Unlimited Server. No Download or Time Limits!
> -----==  Over 80,000 Newsgroups - 19 Different Servers!  ==-----

From tanzer at swing.co.at  Tue Sep 11 03:26:22 2001
From: tanzer at swing.co.at (Christian Tanzer)
Date: Tue, 11 Sep 2001 09:26:22 +0200
Subject: Proposed PEP for a Conditional Expression 
In-Reply-To: Your message of "Mon, 10 Sep 2001 10:15:16 +0200."
             <00e801c139d0$b9d1cdc0$102b2bc1@cadlab.it> 
Message-ID: 

"Alex Martelli"  wrote:
> """
> One example: with a trivial class, one can put expressions into format
> directives, like
> 
>     "Found %(number)d error%(if number == 1 : '' else : 's')s" % trivial
> 
> This doesn't look too attractive if used in a one-liner, put could be
> put to very good use for substitution in bigger templates.
> """
> Definitely unattractive here -- and you don't really need to
> change the Python language, adding complication to it, to get
> a similar effect right now.  The __getitem__ method of the
> class of 'trivial' can after all perfectly well define whatever
> syntax it wants (as long as it's free of ')' charachters:-)
> for its 'name' argument.  E.g., assuming it's OK to exclude
> '@' and ':' as well, since ')' has to be excluded anyway:

Sure, that's one of Python's strengths. I just think it's a waste if
everybody implements his own pet class to solve one specific instance
of a general problem like this.

IMHO, conditional expressions add substantial benefit if the syntax is 
readable.

> In fact, I'd prefer a totally different
> approach here, one allowing me to write, e.g.:
> 
> print "%(plur_verb number 'Found') %(plur_noun number 'error')s" % neater
> 
> with the parser in __getitem__ looking for spaces and using
> them, if found, to recognize formatting keywords such as
> 'plur_verb' -- makes for easier parsing AND for vastly easier
> i18n of messages (neater itself would of course use gettext
> as needed on the meaning-carrying words such as 'error' or
> 'Found':-).

Well, I'd use the contents of the interpolated string as key to get 
the translation (via gettext or otherwise). After all, different
languages might have totally different rules how to adapt a sentence
to the context supplied by `neater`.

-- 
Christian Tanzer                                         tanzer at swing.co.at
Glasauergasse 32                                       Tel: +43 1 876 62 36
A-1130 Vienna, Austria                                 Fax: +43 1 877 66 92

From James_Althoff at i2.com  Fri Sep 14 16:35:06 2001
From: James_Althoff at i2.com (James_Althoff at i2.com)
Date: Fri, 14 Sep 2001 13:35:06 -0700
Subject: Proposed PEP for a Conditional Expression
Message-ID: 

Marcin Kowalczyk wrote:
>    abs = if x>=0 then x else -x
>or
>    abs = if x>=0: x else: -x
>looks more readable than
>    abs = cond(x>=0, lambda:x, lambda:-x)
>for me.

That's a fair opinion.  But you have to admit that the last one beats the
heck out of the first two in terms of implementation issues.

And is not nearly as humorous as
    abs = (x>=0 and [x] or [-x])[0]
as an available workaround.  ;-)

Jim

From tim at vegeta.ath.cx  Wed Sep 12 16:53:21 2001
From: tim at vegeta.ath.cx (Tim Hammerquist)
Date: Wed, 12 Sep 2001 20:53:21 GMT
Subject: .NET and Python
References:  <9nettc$ce1$1@slb7.atl.mindspring.net>    <8nMm7.133116$n75.31959718@news4.rdc1.on.home.com>   <9hCn7.1041$6c5.37802@news1.rdc1.sdca.home.com>
Message-ID: 

Me parece que Van Gale  dijo:
[ snip ]
> Most, if not all, Microsoft products improve with time.

I think fortune said it best when it said:

$ /usr/games/fortune
The Microsoft Motto: "We're the leaders, wait for us!"
$

There you have it.  ;)

Tim

[ snip ]

-- 
Well of *course* Perl should not be taught to everyone. It should
only be taught to people who want to like their computers.
    -- Larry Wall

From danny.kohn at systematik.se  Sat Sep 15 11:57:13 2001
From: danny.kohn at systematik.se (Danny Kohn)
Date: 15 Sep 2001 11:57:13 CET
Subject: Newbee - MySQL create database/table
Message-ID: <1103_1000547896@DANNY>

Hi.
I wonder if someone could put here or send me a sample Python scrip on how to create a database and how to create a table using MySQL with MySQLdb.
I have read a lot of documentation but I just cannot figure this one out or find any sample script on how to do this.

Thanks in advance 
/Danny Kohn

From slinkp23 at yahoo.com  Fri Sep  7 17:22:12 2001
From: slinkp23 at yahoo.com (Paul Winkler)
Date: Fri, 07 Sep 2001 21:22:12 GMT
Subject: pymacs! :-)
References:  <6e0ad3b1.0109060128.6c9adc8@posting.google.com> 
Message-ID: 

On 06 Sep 2001 11:39:18 -0400, Fran?ois Pinard  wrote:
(snip)
>It depends a bit on if there are many Emacs users who have practical
>interest in writing `.py'/`.pyc' files next to their `.el`/`.elc' files!

Very much so! I love emacs, but there is a lot I can do in python that
I haven't a clue how to do in emacs lisp. (well, almost anything!)

I hope you'll excuse the lisp-newbie questions, but I think a simple
example would really help me understand how this is going to work.
For example, let's say I have a a module, let's call it manglers.py,
containing this simple python function:

def break_on_whitespace(some_string):
	"""Yes, it's trivial."""
	words = some_string.split()
	return '\n'.join(words)

Now I want to tell Emacs about this function so that I can call it on
a region of text and replace the region with the result of the
call. And bind this action to a key, of course.

So what goes in my .emacs file?
First I import the module:
(import-python 'manglers')

Then I can refer to (manglers-break_on_whitespace), right?
And I think I can bind it to a key like so:
(global-set-key (quote [f7]) (quote manglers-break_on_whitespace))

But how do I pass and replace the current region?  I was hoping this
project of yours might enable me to avoid learning any more lisp, but
it looks like I won't be so lucky. :)

--PW

From phr-n2001 at nightsong.com  Tue Sep 25 12:10:03 2001
From: phr-n2001 at nightsong.com (Paul Rubin)
Date: 25 Sep 2001 09:10:03 -0700
Subject: Threading and the HTTPD server classes
References: 
Message-ID: <7xvgi7qmjo.fsf@ruckus.brouhaha.com>

I think you're supposed to do that using the ThreadingMixIn from the
SocketServer class.

From aahz at panix.com  Sun Sep 30 12:47:11 2001
From: aahz at panix.com (Aahz Maruch)
Date: 30 Sep 2001 09:47:11 -0700
Subject: Realtime capabilities?
References:  <9ol2ph$od2$1@panix2.panix.com> 
Message-ID: <9p7iaf$gqf$1@panix3.panix.com>

In article ,
Carlos Gaston Alvarez  wrote:
>
>Why there is a stack and a stackless python?
>The cuestion is: why not using allways stackless?

The current implementation of Stackless Python is too Baroque to be
integrated into the Python core.  If it ever does happen, it'll probably
be after Python 3.0.
-- 
                      --- Aahz  <*>  (Copyright 2001 by aahz at pobox.com)

Hugs and backrubs -- I break Rule 6                 http://www.rahul.net/aahz/
Androgynous poly kinky vanilla queer het Pythonista   

We must not let the evil of a few trample the freedoms of the many.

From MarkH at ActiveState.com  Mon Sep  3 21:32:44 2001
From: MarkH at ActiveState.com (Mark Hammond)
Date: Tue, 04 Sep 2001 01:32:44 GMT
Subject: Questions on COM Objects scripting
References: 
Message-ID: <3B942FF4.9040006@ActiveState.com>

Maan Hamze wrote:

> Taking into account that the very same thing works fine with something like
> "Excel.Application"; what does this error tell me about "Breeze.Scene"?

That Breeze.Scene is not registering itself in the "Running Object 
Table".  This should not be a problem - the fact that Excel works is 
more unusual than the fact that Breeze.Scene does not.

> 2.  Using Python ActiveScripting
> From inside the applicatio itself (Breeze Designer) there is a facility to
> run Macros with languages with ActiveScripting capabilities including
> Python.
> "Breeze.Scene" is created automatically when Breeze is started.
> a macro starts with $Scripting_Language

"Breeze.Scene" should not be created automatically - that would suck. 
Hopefully what you mean is that a "Breeze" object is created, and it 
should have a "Scene" attribute.

You could try printing "globals()" to see exactly what is in the 
ActiveScripting namespace.  If "Breeze.Scene" really does exist in the 
namespace, then we will need to pull some tricks to work around a very 
poor decision by the povray people.

Keep in mind that VB is not case sensitive, but Python is.  Have you 
tried "breeze"?

Mark.

From Dag at animagicnet.no  Mon Sep  3 05:11:26 2001
From: Dag at animagicnet.no (Dag)
Date: 3 Sep 2001 09:11:26 GMT
Subject: cgi type=file problems
Message-ID: 

I have a HTML form with a type=file input element and I simply want to
get the file name as a string.  I'm not interested in the actual file.  
However the value from the file part of the form doesn't seem to get
passed at all. 
For example I have the following form and script;

#!/usr/bin/python
import cgi
form=cgi.FieldStorage()
#other stuff
print form

When I enter a filename and text string into the form, the above code
returns;

FieldStorage(None, None, [MiniFieldStorage('texttest', 'abc')])

So what happened to my "filetest" value?

Dag

From fredrik at pythonware.com  Mon Sep 17 13:13:56 2001
From: fredrik at pythonware.com (Fredrik Lundh)
Date: Mon, 17 Sep 2001 17:13:56 GMT
Subject: newbie - Scoping question
References: <3281a460.0109170759.63ede66@posting.google.com>
Message-ID: 

"P Adhia" wrote:
> I'll appreciate if anyone can me clarify my Python scoping rules a
> bit.

scoping has nothing to do with this.

> >>> from test import *

in Python, a variable is a name associated with an object.

the from-import statement creates new names, in the current
module, which points to existing objects from another module.

> >>> x = [1,2,3]

assignment also creates new names in the current module.

the above statement doesn't modify the original "x" object;
it creates a new list, and gives it a name.

> I am confused as to why "x", when not qualified with module name, does
> not refer to "x" in "test", even though I did "from test import *".

if the introductory book you used to learn Python didn't explain
this, ask for a refund ;-)

reading the following articles might help:

    http://effbot.org/guides/python-objects.htm
    http://effbot.org/guides/import-confusion.htm

From cgale1 at _remove_home.com  Wed Sep 12 18:59:49 2001
From: cgale1 at _remove_home.com (Van Gale)
Date: Wed, 12 Sep 2001 22:59:49 GMT
Subject: .NET and Python
References:  <9nettc$ce1$1@slb7.atl.mindspring.net>    <8nMm7.133116$n75.31959718@news4.rdc1.on.home.com>   <9hCn7.1041$6c5.37802@news1.rdc1.sdca.home.com> <9nnknh02j8b@enews1.newsguy.com>
Message-ID: 

"Alex Martelli"  wrote in message
news:9nnknh02j8b at enews1.newsguy.com...

> ...for *networking* purposes, probably.  It's likely to be pretty
> soon a superior way to develop & deploy for the Windows *desktop*,
> greatly reducing issues of component versioning and other aspects
> of "dll hell":-).

Interesting.  If that's the case, maybe I'll be using it sooner rather than
later *grimaces*

From rnd at onego.ru  Sun Sep 23 17:13:10 2001
From: rnd at onego.ru (Roman Suzi)
Date: Mon, 24 Sep 2001 01:13:10 +0400 (MSD)
Subject: google, Python, and eleven (was Re: google and Python ;-)
In-Reply-To: <3BAD2890.FDE4B2F7@engcorp.com>
Message-ID: 

On Sat, 22 Sep 2001, Peter Hansen wrote:

>>>> def numerology(s):
>...     f = lambda x, y : x+y
>...     return reduce(f, map(int, str(reduce(f, map(ord, s)))))
>...
>>>> numerology('readablepowerfuldynamic')
>11
>>>> numerology('Perl')
>7
>>>> numerology('Python')
>12
>>>> numerology('Ruby')
>13
>>>> numerology('Smalltalk')
>15
>>>> numerology('TCL')
>11

Lets make PEP 11 about Numerology constraints on Python module names.
There must be standard numerology API so nobody will abuse the science
any more! (And backdoors for the gov'ts, as usual ;-)

I am not sure ASCII codes is suitable for such use, though.

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Sunday, September 23, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "Alexander the Grape: He Concord the world." _/

From rafael at zumnet.com.br  Fri Sep 14 10:19:36 2001
From: rafael at zumnet.com.br (Rafael Mentz Aquino)
Date: Fri, 14 Sep 2001 11:19:36 -0300
Subject: Sockets
Message-ID: <3BA211F8.DFCD@zumnet.com.br>

Hi, there,

I'm trying to create a socket script to work as server,
using the example from the lib reference manual,
with a little change that puts the script in looping,
so I can make more than one requisition without stopping
and starting the script all the time.

When I execute the script, it works fine, listening in the
given port and answering the requisitions...

But If I try to put the script in background (in FreeBSD)
I got an error saying (address already in use). I guess
its because of the while 1 looping...

The script is below.

Thanks!!!

Rafael Mentz Aquino

     1 #!/usr/local/bin/python
      2
      3 import socket, sys, string
      4
      5 data = ""
      6
      7 def sock():
      8    data = ""
      9
     10    HOST='127.0.0.1'
     11    PORT=50007
     12    s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
     13    s.bind((HOST,PORT))
     14    s.listen(1)
     15    s.setblocking(1)
     16    conn, addr = s.accept()
     17    print 'Connected by', addr
     18    while 1:
     19       data = conn.recv(1024)
     20
     21       if data == "quit" : sys.exit()
     22
     23       if data == "server": .... etc etc
     ....
    ....
     100     if not data:
     101               conn.close()
     102                break
     103  while not data == "quit":             ## It's a redundancy, I
know.. ;-)
     104         socks()
     105  conn.close()

From fredrik at pythonware.com  Thu Sep  6 14:27:45 2001
From: fredrik at pythonware.com (Fredrik Lundh)
Date: Thu, 06 Sep 2001 18:27:45 GMT
Subject: problem with re
References: <9n8atr$i22$1@odysseus.uci.kun.nl>
Message-ID: 

Patrick Vrijlandt wrote:
> I do not understand why the 7th regular expression does not give the same
> result as 2-6.

because "|" has lower precedence than just about everything
else; the last pattern either matches 10 digits, *OR* two letter
groups followed by a number.

> mymatch(r'\n'.join([r'(\d{10})|([a-z]{10})', r'([a-z]{10})', r'(\d{10})']))

if you want three groups, remove the parens around the bar:

    mymatch(r'\n'.join([r'(\d{10}|[a-z]{10})', r'([a-z]{10})', r'(\d{10})']))

if you want four groups, you have to add an extra pair of non-capturing
parentheses:

    mymatch(r'\n'.join([r'(?:(\d{10})|([a-z]{10}))', r'([a-z]{10})', r'(\d{10})']))

From phd at phd.pp.ru  Sat Sep  8 05:36:02 2001
From: phd at phd.pp.ru (Oleg Broytmann)
Date: Sat, 8 Sep 2001 13:36:02 +0400
Subject: Creating Excel files on Linux
In-Reply-To: ; from mmhamze@pleiades.net on Fri, Sep 07, 2001 at 11:04:37AM -0500
References: <3B97A39C.6A5234D7@olen.to>      
Message-ID: <20010908133602.M18172@phd.pp.ru>

Hello!

   Completely offtopic. Sorry, I cannot resist. Well...

On Fri, Sep 07, 2001 at 11:04:37AM -0500, Maan M. Hamze wrote:
> living in.  I am not defending Microsoft here, but I am being realistic.

   In you realism you said many bad words about people and companies. I
don't want to be that kind of "realist". I want to be an idealist. Only
idealists can change the world. Realists seems to be slaves of the status
quo. (I am not flaming you, don't take it personnaly.)

> transparent.  We do not live in such a world.  We live in a world controlled
> by greedy corporations, let it be Sun or Microsoft or the late Netscape.

   That why instead of just being realistical slaves we must oppose them
and create the free world.

> We live in a world of arrogant men and greedy corporations, and they play

   Thanks goodnes I am not. I live in the world of nice, creative, open,
very helpful people. Gvido van Rossum, Eric Raymond, Linus Torvalds (to
name a few most notable persons); and they are not only brilliant
programmers - they are idealists who are changing the world. Linux and
"Computer Programming for Everybody", Python and Free Software Movements!

> As far as I am concerned, getting a job done is the issue here.  Anyone can

   Not only. Protecting our freedom, too.

Oleg.
---- 
     Oleg Broytmann            http://phd.pp.ru/            phd at phd.pp.ru
           Programmers don't die, they just GOSUB without RETURN.

From marcinm at finisar.com  Tue Sep  4 20:01:11 2001
From: marcinm at finisar.com (Marcin Matuszkiewicz)
Date: 4 Sep 2001 17:01:11 -0700
Subject: swig cygwin python
Message-ID: 

I am using swig to generate a wrapper around C functions I want to
call from python.  I am using gcc2.95.3-5 (cygwins pecial) and python
2.1 that come with cygwin.  I have a linker problem when creating .so
file.  Here are the details.
$ swig -python example.i
Generating wrappers for Python
$ gcc -c example.c
$ gcc -I/usr/include/python2.1 -c example_wrap.c
$ gcc -shared example.o example_wrap.o -L/lib/python2.1/config
-lpython2.1.dll
example_wrap.o(.text+0x1e6):example_wrap.c: undefined reference to
`PyExc_NameEr
ror'
example_wrap.o(.text+0x2b8):example_wrap.c: undefined reference to
`PyExc_NameEr
ror'
example_wrap.o(.text+0x305):example_wrap.c: undefined reference to
`PyType_Type'
example_wrap.o(.text+0xef0):example_wrap.c: undefined reference to
`PyExc_TypeEr
ror'
collect2: ld returned 1 exit status
$ nm /lib/python2.1/config/libpython2.1.dll.a | grep NameError
00000000 I __imp__PyExc_NameError
Does anyone know what is going on and/or how to fix it?
Thank you,
Marcin

From ScottMC at oge.com  Mon Sep 17 11:38:32 2001
From: ScottMC at oge.com (Scott, M Clay)
Date: Mon, 17 Sep 2001 10:38:32 -0500
Subject: Best database for Time Series Data [slightly OT]
Message-ID: <66757C91639C7C419D9AD6C8925C5E3EE697B5@chqmail.corp.oge.com>

While this is slightly off-topic in a general sense, it is on-topic from a
Python sense...

What is the best database to use for time-series data?  I work for an
electric utility in Load Research.  Load Research is the study of how
customers and groups of customers use energy.  It deals with large amounts
of time-series data (periodic meter readings on [typically] 15-minute
intervals).  The volume of data would be in the magnitude of 35,000 (for a
single meter) to 35,000,000 (for a group of 1,000 meters) data elements for
a single year.  Obviously, multiple years means more data.

I am looking to take advantage of Python for some of the data processing.
We currently use a package that utilizes Btreive which can be connected to
via ODBC.  However, I would like to know about other alternatives.

Is MySQL well-suited for this task?  What are other Python-able databases?
Which of these are good for time-series data?

Any direction provided will be greatly appreciated.

Thanks,

Clay Scott

From orlov at diasoft.ru  Fri Sep 21 02:52:29 2001
From: orlov at diasoft.ru (Oleg Orlov11980884)
Date: Fri, 21 Sep 2001 10:52:29 +0400
Subject: attribut of the current module
Message-ID: <9oeo0n$28vn$1@gavrilo.mtu.ru>

How can i get attribut of the current module?

Ugly way: getattr(__import__(__name__), attribname)

Thnks, Oleg.

From TomH at optiscan.com  Wed Sep  5 02:18:32 2001
From: TomH at optiscan.com (Tom Harris)
Date: Wed, 5 Sep 2001 16:18:32 +1000 
Subject: string.split
Message-ID: 

Hi,

The useful split() function in the string module by default splits on
whitespace, which is any combination of spaces, tabs, newlines, and possibly
other stuff. So I see the following behaviour:

>>> import string
>>> s = 'asa   \n  bb cc\n\tdd'
>>> string.split(s)
['asa', 'bb', 'cc', 'dd']

However the defaulted second argument to string.split() can only be used to
set a literal string that is the seperator. How do I split on any or all
occurrences of (for example) whitespace and a comma, without using regexes.
I mean string.split() must be able to do it anyway to achieve the default
behaviour. 

Tom Harris, Software Engineer
Optiscan Imaging, 15-17 Normanby Rd, Notting Hill, Melbourne, Vic 3168,
Australia
email tomh at optiscan.com     ph +61 3 9538 3333  fax +61 3 9562 7742

This email may contain confidential information. If you have received this
email in error, please delete it immediately,and inform us of the mistake by
return email. Any form of reproduction, or further dissemination of this
email is strictly prohibited. Also, please note that opinions expressed in
this email are those of the author, and are not necessarily those of
Optiscan Pty Ltd.

From tanzer at swing.co.at  Mon Sep 10 02:42:16 2001
From: tanzer at swing.co.at (Christian Tanzer)
Date: Mon, 10 Sep 2001 08:42:16 +0200
Subject: Proposed PEP for a Conditional Expression 
In-Reply-To: Your message of "Sun, 09 Sep 2001 20:00:05 +0200."
             <9nganb0t8f@enews1.newsguy.com> 
Message-ID: 

> Michael Chermside wrote:
> 
> [excellent work snipped, as I just want to snipe on one point...]
> 
> >              using it may require creating a temporary variable and
> >              splitting a formula into two lines, or replacing a lambda
> >              expression with a named function.
> 
> I consider that replacing lambda forms with named functions, in Python, is 
> an *excellent* practice, which should be encouraged by all means necessary. 
>  If the lack of a conditional operator does indeed encourage people to 
> write more local def's and fewer lambdas, then (to me) that is the "killer 
> argument" for not introducing conditional operators.

Conditional expressions provide some nice benefits totally unrelated
to lambdas.

One example: with a trivial class, one can put expressions into format
directives, like

    "Found %(number)d error%(if number == 1 : '' else : 's')s" % trivial

This doesn't look too attractive if used in a one-liner, put could be 
put to very good use for substitution in bigger templates.

-- 
Christian Tanzer                                         tanzer at swing.co.at
Glasauergasse 32                                       Tel: +43 1 876 62 36
A-1130 Vienna, Austria                                 Fax: +43 1 877 66 92

From vincent_delft at yahoo.com  Fri Sep 14 10:13:57 2001
From: vincent_delft at yahoo.com (vincent delft)
Date: Fri, 14 Sep 2001 16:13:57 +0200
Subject: what's the best methode to crypt/encode the python code.
Message-ID: <3BA210A5.E027C11B@yahoo.com>

hello,

I've written a Python code that check an application (registration into
the DB, execution of commands, ...).  And I would like to put this code
on the production machine.
My problem is that some passwords and some private info are into the
python code.

How can we secure it ?
I don't want that someone (the others that have acccess to the machine)
can read this code.

Do I use a DB ? (which often provide more secure access)

unfortunately I'm on a windows server

Thanks

From kkto at csis.hku.hk  Thu Sep 20 06:49:05 2001
From: kkto at csis.hku.hk (Isaac To)
Date: 20 Sep 2001 18:49:05 +0800
Subject: How to remove "\n" in a string?
References: 
Message-ID: <7i3d5if87y.fsf@enark.csis.hku.hk>

>>>>> "rainlet" == rainlet   writes:

    rainlet> I tried : s = ".............."  s.replace ( "\n", "" )

    rainlet> But it doesn't seem to work.

If you remember that strings are immutable, you'd probably have written
s = s.replace(...), which should do the trick.

Regards,
Isaac.

From mr.murray at mindspring.com  Sun Sep  9 01:18:52 2001
From: mr.murray at mindspring.com (Andrew Murray)
Date: Sat, 8 Sep 2001 22:18:52 -0700
Subject: Python and Zope
References: 
Message-ID: <9nettc$ce1$1@slb7.atl.mindspring.net>

Frankly I was pretty unimpressed with Zope. After one gets over the
'gee-whiz' factor,
I've found that the learning curve behind Zope and the relative
non-portability of the code you
must write for it far outweigh the benefits (what are they again btw?) of
using Zope.

If you've used mod_perl, mod_php or mod_python before, I'd suggest going
that route.

Andrew Murray
"Ken Egervari"  wrote in message
news:vLAm7.129206$n75.31076306 at news4.rdc1.on.home.com...
> How realistic is it to make large, corporate websites and extranets using
> Zope?  It is it better to just use Python and a regular web server?  (like
> say amazon.com, ibm.com, bea.com).  Basically anything that sapient or
> razorfish does.
>
>

From hao-nghi.au at fr.thalesgroup.com  Wed Sep 12 12:41:56 2001
From: hao-nghi.au at fr.thalesgroup.com (hao-nghi.au at fr.thalesgroup.com)
Date: Wed, 12 Sep 2001 18:41:56 +0200
Subject: os.spawn
Message-ID: <33105F8B185CD51182E300306E06473E270205@hermes.isr.thomson-csf.com>

Hi Sylvain,

when you use os.P_NOWAIT, you get the pid of the process. Perhaps you can
get its return status by waitpid().

Regards,
Hao-Nghi Au

-----Original Message-----
From: syt at pegasus.logilab.fr [mailto:syt at pegasus.logilab.fr]
Sent: Wednesday, September 12, 2001 3:33 PM
To: python-list at python.org
Subject: Re: os.spawn

On Wed, 12 Sep 2001 09:13:58, S. Thenault  wrote:
>On 11 Sep 2001 18:05:13 GMT, Donn Cave  wrote:
>>Quoth syt at pegasus.logilab.fr (Sylvain Thenault):
>>
>>| how can I do for knowing what happend when I do an os.spawnv()
>>|
>>| for example, if i do
>>|
>>| import os
>>| os.spawnv(P_WAIT, '/bin/echo', 'this is a spawn test')
>>|
>>| I can't see anything, and don't know what have been made...
>>
>>Normal return from os.spawnv should be 0.  Anything else indicates
>>failure.
>>
>>   >>> print os.spawnv.__doc__
>>   spawnv(mode, file, args) -> integer
>>
>>   Execute file with arguments from args in a subprocess.
>>
>>Args here should be a tuple or list like sys.argv:
>>   os.spawnv(os.P_WAIT, '/bin/echo', ('echo', 'this is a spawn test'))
>>
>>	Donn Cave, donn at u.washington.edu
>
>thanks, i was waiting for an exception in case of error 
>does someone know why it isn't the default behaviour ?
>
>BTW, this wasn't working because as exec*, the first item of args must be 
>the called program's name ('echo' in this example)
as you said (i read your message too fast, didn't see you said that yet)

I have now another problem, I change P_WAIT to P_NOWAIT and spawnv return 
an integer != 0 either if spawnv succeed !

how to know if there is an error durring spawn with the P_NOWAIT flag?

-- 
Sylvain Thenault

LOGILAB

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

From phd at phd.pp.ru  Sun Sep 30 11:13:55 2001
From: phd at phd.pp.ru (Oleg Broytmann)
Date: Sun, 30 Sep 2001 19:13:55 +0400
Subject: Off-topic: hiding your email address - don't bother...
In-Reply-To: <9p6jur.3vv985j.1@kserver.org>; from sheila@spamcop.net on Sun, Sep 30, 2001 at 03:09:07PM +0000
References:  <9p5aio$50a$1@inputplus.demon.co.uk>  <3BB6C9DD.E36C0BFF@engcorp.com>  <9p6jur.3vv985j.1@kserver.org>
Message-ID: <20010930191355.B892@phd.pp.ru>

On Sun, Sep 30, 2001 at 03:09:07PM +0000, Sheila King wrote:
> I've often thought, that email addresses with the string "spam" just get
> discarded. Otherwise, I don't know why I get so few spam emails sent to
> my spamcop.net address.

   Probably because SpamCop.NET does an enormous effort to filter it before
you see it.

Oleg.
---- 
     Oleg Broytmann            http://phd.pp.ru/            phd at phd.pp.ru
           Programmers don't die, they just GOSUB without RETURN.

From markus at schabi.de  Wed Sep 12 04:55:14 2001
From: markus at schabi.de (Markus Schaber)
Date: Wed, 12 Sep 2001 10:55:14 +0200
Subject: Pythonwin and .NET
References: 
Message-ID: <1289505.6RcZxFsPTI@lunix.schabi.de>

Roman Suzi  schrub:

> On Tue, 11 Sep 2001, Robin Becker wrote:
> 
>> In article , Roman
>> Suzi  writes
>> ...
>> >"Python! Python! Python! ..."
>> >
>> >And then elect GvR the president of United Nations.
>> >
>> >Sincerely yours, Roman Suzi
>> hope not, else perhaps 10 years down the road we'll have United
>> Nations 2.2 with qualified minority voting or some such.
> 
> But we will have too:
> 
> from __future__ import hope

Bob Hope as python module? Bizarre :-)

markus
-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From markus at schabi.de  Wed Sep 19 14:53:13 2001
From: markus at schabi.de (Markus Schaber)
Date: Wed, 19 Sep 2001 20:53:13 +0200
Subject: confused by bindings
References: 
Message-ID: <1163217.ysRUnXabfl@lunix.schabi.de>

Hi,

Sam Falkner  schrub:

> class Cell:
>     count = 0

This is the "class variable" called count.

>     def __init__(self, stuff):
>         self.count += 1

Here, you set an "instance variable" count. That's why you always get 1.

Try Cell.count += 1 here.

markus
-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From l0819m0v0smfm001 at sneakemail.com  Thu Sep 13 18:26:03 2001
From: l0819m0v0smfm001 at sneakemail.com (Joshua Macy)
Date: Thu, 13 Sep 2001 22:26:03 GMT
Subject: MUDs...
References:  <9nqic4$and$1@hfc.pacific.net.hk>
Message-ID: <3BA0FC3B.9030806@sneakemail.com>

   Poo was renamed MOOP, and is now on SourceForge at 
http://moop.sourceforge.net

Joshua

Kenneth Tsang wrote:

> hi, I come across this. - Pythonic MOO
> http://www.strout.net/python/poo/index.html
> 
> KT
> --
> 
> --
> Kenneth Tsang
> email: smt at pacific.net.hk tel: +852 9468 4772
> "Vincent A.Primavera"  wrote in message
> news:mailman.1000384156.22009.python-list at python.org...
> 
>>Hello,
>>A while ago on the list, Python based MUDs were discussed.  Does anyone
>>
> have any suggestions as to
> 
>>which were/are recommended?
>>
>>Thank you,
>>Vincent A. Primavera.
>>
>>
> 
> 

From g.haering at ___skynamics.com.invalid  Wed Sep  5 08:10:39 2001
From: g.haering at ___skynamics.com.invalid (Gerhard =?ISO-8859-1?Q?H=E4ring?=)
Date: Wed, 05 Sep 2001 14:10:39 +0200
Subject: running Python-Skripts without having Python installed
References: <9n4tsa$gl5$1@trinity.hannover.sgh-net.de>
Message-ID: <3B96163F.60506@___skynamics.com.invalid>

Frank Bongartz wrote:
> Hi !
> 
> As I am new to Python I wonder if it is possible to run Python scripts on
> machines, that do not have installed Python.
> 
> In TCL, it is possible to start a "wish" in a batch-file, followed by the
> tcl-script.
> 
> Any suggestions ?

win32/Linux: 	http://www.mcmillan-inc.com/install1.html
win32: 		http://py2exe.sourceforge.net/

Gordon McMillan's page (first URL) explains the concepts behind these 
quite nicely.

There's also the freeze utility in the standard Python distribution, 
which should work on any platform, but needs a C compiler.

Gerhard
-- 
Gerhard H?ring
skynamics AG
g.haering at skynamics.com
http://www.skynamics.com

From nhodgson at bigpond.net.au  Mon Sep 24 04:29:41 2001
From: nhodgson at bigpond.net.au (Neil Hodgson)
Date: Mon, 24 Sep 2001 08:29:41 GMT
Subject: Why so few Python jobs?
References: <9oltnk$vv3$1@nntp9.atl.mindspring.net>
Message-ID: 

Ted:
> Any ideas on why so few Python jobs are available?

   Unfortunately, the increased productivity we achieve with Python means
that there is often no need to hire any more developers after your first
Pythonista ;)

   Neil

From chrishbarker at home.net  Tue Sep  4 19:45:49 2001
From: chrishbarker at home.net (Chris Barker)
Date: Tue, 04 Sep 2001 16:45:49 -0700
Subject: appropriate graphics Lib?
References:  <3B955860.8040303@visionart.com>
Message-ID: <3B9567AD.5B2228B8@home.net>

Pete Shinners wrote:

> i hear tkinter has a pretty powerful canvas widget that i
> supports these things. i'm guessing wxPython would have
> something like that too.

Actually, the fact that wxPython does NOT have such a canvas widget is
seen by many as it's greatest weekness (in comparison to tk, anyway). In
wxPython, you would have to do the hit test yourself as well. There is a
C++ wxCanvas that would do it, but it is not yet complete, and has not
yet been wrapped for Python.

TK is probably the easiest way to do it.

-Chris

-- 
Christopher Barker,
Ph.D.                                                           
ChrisHBarker at home.net                 ---           ---           ---
http://members.home.net/barkerlohmann ---@@       -----@@       -----@@
                                   ------@@@     ------@@@     ------@@@
Oil Spill Modeling                ------   @    ------   @   ------   @
Water Resources Engineering       -------      ---------     --------    
Coastal and Fluvial Hydrodynamics --------------------------------------
------------------------------------------------------------------------

From jblazi at hotmail.com  Sat Sep 22 15:18:35 2001
From: jblazi at hotmail.com (Janos Blazi)
Date: Sat, 22 Sep 2001 21:18:35 +0200
Subject: Tkinter Questions
References: 
Message-ID: <3bace41a_8@news.newsgroups.com>

> 1)   Use winfo_width() and winfo_height() to get the actual
>      dimensions of a component. Call update() first so that
>      the geometry manager has run...
>
> from Tkinter import *
> root = Tk()
>
> f1 = Frame(root, width=300, height=250)
> f1.pack()
> root.update()
> w = f1.winfo_width()
> h = f1.winfo_height()
> f2 = Frame(f1, width=w, height=h)
> f2.pack(fill=BOTH)
> c = Canvas(f2, width=w, height=h, bg='yellow')
> c.pack(fill=BOTH)
>
> root.mainloop()
>
>
> 2) Try using:
>        ~~counter~~.entryfield.component('entry').configure( options...)

Thank you very much, now evrything works and I am sure I should have never
found out, how to do these things.

Apropos update():
"Use this method with care, since it can be a source of problems, not only
by consuming CPU cycles but also by setting up race conditions." (page 440)

Janos Blazi

-----=  Posted via Newsfeeds.Com, Uncensored Usenet News  =-----
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From paoloinvernizzi at dmsware.com  Tue Sep 25 03:54:44 2001
From: paoloinvernizzi at dmsware.com (Paolo Invernizzi)
Date: Tue, 25 Sep 2001 07:54:44 GMT
Subject: python 2.2 question...
References:  <1387386.JiE95MRjnR@lunix.schabi.de>
Message-ID: <8LWr7.8$sk6.469@nreader1.kpnqwest.net>

Markus Wrote...
-------------
> try setting A.__repr__ to a method or function doing whatever you want.
>
> >>> A.__repr__ = lambda: "hallo"
> >>> print A
> hallo
> >>> str(A)
> 'hallo'
-------------

Things work differently in 2.2, and not only for "object" derived classes...
(for now ;)

Python 2.2a3 (#23, Sep  7 2001, 01:43:22) [MSC 32 bit (Intel)] on win32
Type "copyright", "credits" or "license" for more information.
IDLE 0.8 -- press F1 for help

>>> class A: pass
>>> A.__repr__= lambda: "Repr of A"
>>> print A
__main__.A
>>> str(A)
'__main__.A'
>>> repr(A)
''

>>> class A(object):  pass
>>> A.__repr__= lambda: "Repr of A"
Traceback (most recent call last):
  File "", line 1, in ?
    A.__repr__= lambda: "Repr of A"
TypeError: can't set type attributes

Paolo Invernizzi

From root at rainerdeyke.com  Thu Sep 13 22:45:26 2001
From: root at rainerdeyke.com (Rainer Deyke)
Date: Fri, 14 Sep 2001 02:45:26 GMT
Subject: Proposed PEP for a Conditional Expression
References:  <6qvgire4bk.fsf@abnoba.intevation.de> <9nk3jd$4lc$1@glue.ucr.edu> <9nnsa3$bjl$1@news.mathworks.com>  <3BA00239.DECE6412@cosc.canterbury.ac.nz> <4xXn7.2446$w62.1612552@news1.denver1.co.home.com> <3BA13B35.991482C4@cosc.canterbury.ac.nz>
Message-ID: 

"Greg Ewing"  wrote in message
news:3BA13B35.991482C4 at cosc.canterbury.ac.nz...
> Rainer Deyke wrote:
> >
> > I was actually considering the following interpretations:
> >
> > [( for i in range(5)) if  else ]
>
> That one isn't even an interpretation, it's nonsense.

Just because it isn't legal Python (now or with conditional statements)
doesn't mean it's nonsense.

> Unless you mean it to mean
>
>   [ for i in range(5)] if  else []

Yes, that is what I mean.

> and I wouldn't mind in the least being required to
> write it like that if that's what I wanted.

You're not addressing the real point.  With the ' if  else
' syntax, an 'if' enclosed in brackets has two very different meanings
depending on whether or not there is an else.  This makes Python harder to
read, write, and grok - *unless* the new syntax is somehow conceptually
unified with the list comprehension syntax.

One problem is that list comprehension syntax is already confusing:

  [i for i in range(5)]

It's easy to think of 'i for i in range(5)' as an expression that yields
multiple values and can therefore only exist in the special context of a
list literal.  This view is unfortunately incorrect:

  [(x, y) for x in range(5) for y in range(5)]

My instincts tell me that '(x, y) for x in range(5)' is evaluated for each
'y' in 'range(5)', but in fact it's the other way around: 'for x in
range(5)' is the outer loop and 'for y in range(5)' is the inner.  The 'for'
and 'if' clauses in a list comprehension do not act like expressions.
Imagine then the confusion if the ' if  else ', which
*does* act like an expression, was added to the language.

--
Rainer Deyke (root at rainerdeyke.com)
Shareware computer games           -           http://rainerdeyke.com
"In ihren Reihen zu stehen heisst unter Feinden zu kaempfen" - Abigor

From aleax at aleax.it  Wed Sep 12 08:11:57 2001
From: aleax at aleax.it (Alex Martelli)
Date: Wed, 12 Sep 2001 14:11:57 +0200
Subject: [Poll] Private variables
References: 
Message-ID: <9nnjee02hg1@enews1.newsguy.com>

"Alexandre Fayolle"  wrote in message
news:slrn9pu9vk.iec.alf at orion.logilab.fr...
> It is possible in python to get private class members by using names
> beginning with 2 underscores, and finished by at least 1 underscore.

Yes, and not only private *class members*: it also works for
class-private *module-level names*, for example:

class One:
    global __beep
    __beep = 23
    def beep(self): print __beep

class Two:
    global __beep
    __beep = 42
    def beep(self): print __beep

One().beep()
Two().beep()
print dir()

will output:

23
42
['One', 'Two', '_One__beep', '_Two__beep', '__builtins__', '__doc__',
'__name__'
]

> I personnally tend to use class member names beginning with one
> underscore to indicate that the member is 'internal' and should not
> be called by external applications, and from looking at the standard
> library source code, it seems that this is more common than the official
> way mentionned hereabove.
>
> I would like to hear what the opinion of pythoneers is on that topic.

My personal opinion is that __beep style names serve to avoid
accidental clashes of identifiers between base and derived
classes -- you can use that style of identifiers without any
worries about some ancestor or descendant class duplicating
it by accident, and that's the only feature that makes them
really useful.  Inheritance hierarchies (particularly between
classes that are separately developed and released) don't
tend to be very deep in most Python code, so it's not such
a crucial issue in most cases.  But it's nice when it comes
up.  And tends to reassure people coming from languages such
as C++ or Java which seem to think privacy is indispensable:-).

Alex

From chrishbarker at home.net  Mon Sep 10 14:37:07 2001
From: chrishbarker at home.net (Chris Barker)
Date: Mon, 10 Sep 2001 11:37:07 -0700
Subject: Performance of list comprehensions vs. map
References: 
Message-ID: <3B9D0853.8B46AE62@home.net>

"Delaney, Timothy" wrote:

> Yep - now you know why so many people have *not* put the effort into
> optimising Python. Dynamism pervades almost every part of the language.
> 
> The only optimisations I've seen proposed in recent times which truly look
> interesting are
> 
> PEP 266: Optimizing Global Variable/Attribute Access
> http://python.sourceforge.net/peps/pep-0266.html
> 
> PEP 267: Optimized Access to Module Namespaces
> http://python.sourceforge.net/peps/pep-0267.html
> 
> both of which need implementing and testing to determine (a) whether they
> are indeed an improvement, and (b) whether they are enough of an improvement
> when balanced by how much they complicate the Python core code.

These both do look good, but let's face it: It's not even clear that
they will help at all, and certainly not enough to make a huge
difference.

My issue with the dynamicism of Python is that it is wonderful and
powerful, but frankly, not used in a great deal of code: How amny people
even new that you could change the code of a function on the fly, let
alone actually used the feature? And of those few that have used the
feature, how often have they used it?

What I am searching for in this discussion are ways that Python can take
advantage of the fact that much code is not, in fact, all that dynamic.
I suspect that most of the time that a list comprehension or map is
called, the author of the code fully expects the expression (or
function) to do the same thing for the duration of the call, and that
the sequence is more often than not homogenous. There must be some way
to take advantage of that circumstance. Granted, we could speed up map
and list comprehensions a whole lot, and that wouldn't speed up the
language as a whole all that much, but this is just an example.

Perhaps the only way to do it would be to sprinkle a few "static" or
something statements in. Frankly I think this is ugly, but the current
answer to a few core functions in a Python program being too slow is to
re-code it in C. Surely that is ugly!

I-know-there-are-no-easy-answers-but-I-wish-there-were-ly yours,

-Chris

-- 
Christopher Barker,
Ph.D.                                                           
ChrisHBarker at home.net                 ---           ---           ---
http://members.home.net/barkerlohmann ---@@       -----@@       -----@@
                                   ------@@@     ------@@@     ------@@@
Oil Spill Modeling                ------   @    ------   @   ------   @
Water Resources Engineering       -------      ---------     --------    
Coastal and Fluvial Hydrodynamics --------------------------------------
------------------------------------------------------------------------

From mats at laplaza.org  Mon Sep 17 07:35:56 2001
From: mats at laplaza.org (Mats Wichmann)
Date: Mon, 17 Sep 2001 11:35:56 GMT
Subject: Getting expat compiled properly
References: <9mkugf$99h$1@tyfon.itea.ntnu.no>  <9n4b8q$ase$1@tyfon.itea.ntnu.no> <3b95f5d8.112439689@news.laplaza.org> <9n508p$let$1@tyfon.itea.ntnu.no>
Message-ID: <3b9ca572.64951735@news.laplaza.org>

On Wed, 5 Sep 2001 12:54:17 +0200, "Magnus Lie Hetland"
 wrote:

:"Mats Wichmann"  wrote in message
:news:3b95f5d8.112439689 at news.laplaza.org...
:[snip]
:> :The problem is that I'm not an administrator at this machine, so
:> :it would be a bit awkward... I guess I could take the #!/usr/bin/env
:> :trick to new heights, but...
:>
:> You're limited to one argument...
:
:I assume that's some strange restriction imposed by using env in the
:hash-bang context? I see that it doesn't work -- although it works in
:other contexts, e.g:
:
:$ env foobar=1 python -c 'import os; print os.getenv("foobar")'
:1

Yes, it's a limit on the #! construct which is a weird hack anyway. 

#! path-to-interpreter argument

You can only pass one argument to the interpreter.  Using env as the
"interpreter" means you're not hardwiring the path to Python but also
means you can't pass /any/ arguments to Python.

Mats Wichmann

From cjensen at bioeng.ucsd.edu  Tue Sep  4 12:05:30 2001
From: cjensen at bioeng.ucsd.edu (Curtis Jensen)
Date: Tue, 04 Sep 2001 09:05:30 -0700
Subject: gdb, python, and irix
Message-ID: <3B94FBCA.CC4343E@bioeng.ucsd.edu>

I'm trying to run gdb with python on irix.  However, I never get passed
the run command in gdb.  It hangs indefinatly after I type "run" in the
gdb shell.  We're using gdb 5.0, irix 6.5 and I've tried Python 1.5.2
and Python 2.1.1  

Has anyone else run into this problem?  Has anyone gotten gdb to work
with Python on irix?  Any suggestions on getting it to work for us? 
Thanks.

-- 
Curtis Jensen
cjensen at bioeng.ucsd.edu
http://www-bioeng.ucsd.edu/~cjensen/
FAX (425) 740-1451

From kkto at csis.hku.hk  Tue Sep 25 08:44:16 2001
From: kkto at csis.hku.hk (Isaac To)
Date: 25 Sep 2001 20:44:16 +0800
Subject: Tkinter and frame resizing question
References: 
 <9opbul$2phe$1@mail1.wg.waii.com> <9opmat$qbk$1@mail1.wg.waii.com>
Message-ID: <7i66a7phi7.fsf@enark.csis.hku.hk>

>>>>> "Martin" == Martin Franklin  writes:

    Martin> post me some code I have done a similar thing and got it
    Martin> working.....

Doesn't seem to work for me.  The question is how to make the bottom window
stay at the same position.  Intuitively, this means that the toplevel window
should "stick" to the bottom.  For example, if the window is of size 100x100
at +100+100 before forget, and is 100x80 after forget, then the position
after resize should be +100+120.

I think this should be wm matters.  However, I've scanned the man page of wm
and toplevel, it doesn't seem to have such an option to allow this.  Perhaps
somebody should actually check ICCCM to see whether this "sticky" option can
be communicated to the window manager.

Regards,
Isaac.

From fredp at mygale.org.nospam  Mon Sep  3 12:45:05 2001
From: fredp at mygale.org.nospam (Fred Pacquier)
Date: 3 Sep 2001 16:45:05 GMT
Subject: (beginner) question on threads...
References:   <3B928478.6DE44401@earthlink.net>  <3066967.SC6OKomogB@lunix.schabi.de>
Message-ID: 

Markus Schaber  said :

>> Is there not a better way ? Some tool that will build a picture of a
>> class from its code, with all its methods and attributes, inherited or
>> not ? 
> 
> That's _really_ difficult in python, because one can add methods or 
> attributes to classes even at run-time, depending on user input or 
> random generators :-)
> 
> But the usual, statically written in source way, it should be possible, 
> I've seen something like this in the Delphi environment, as pop-down 
> menu in the editor.

On the one hand, I'm glad to learn my way of exploring is not so dumb after 
all. OTOH, I'm sadly disappointed that there is no magic bullet :-)

-- 
YAFAP : http://www.multimania.com/fredp/

From qrczak at knm.org.pl  Fri Sep  7 16:49:29 2001
From: qrczak at knm.org.pl (Marcin 'Qrczak' Kowalczyk)
Date: 7 Sep 2001 20:49:29 GMT
Subject: Performance of list comprehensions vs. map
References: <3B966B1C.120D0AF6@home.net>  <9n7n6u02leo@enews1.newsguy.com> 
Message-ID: 

Fri, 07 Sep 2001 20:17:12 GMT, Paul Winkler  pisze:

> So for the foreseeable future, looks like map() is likely to remain
> the fastest way to generate lists.

As long as the function to map is ready. If a separate function must
be created just for mapping (doesn't matter id by 'def' or 'lambda'),
I would expect a list comprehension with the function's body inserted
to be faster than map which must call it.

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZAST?PCZA
QRCZAK

From chatme at 263.net  Thu Sep 13 01:00:41 2001
From: chatme at 263.net (limodou)
Date: 12 Sep 2001 22:00:41 -0700
Subject: About Tkinter <>?
References:  <9np6j1$82u$1@bob.news.rcn.net>
Message-ID: 

Jerry Gitomer  wrote in message news:<9np6j1$82u$1 at bob.news.rcn.net>...
> 
>         You will find a program called GuiAppD.py in the Pmw\contrib 
> directory that does what you want.

Thanks! I'll try.

From rnd at onego.ru  Thu Sep  6 14:18:42 2001
From: rnd at onego.ru (Roman Suzi)
Date: Thu, 6 Sep 2001 22:18:42 +0400 (MSD)
Subject: problem with re
In-Reply-To: <9n8atr$i22$1@odysseus.uci.kun.nl>
Message-ID: 

On Thu, 6 Sep 2001, Patrick Vrijlandt wrote:

>Hi,
>
>I do not understand why the 7th regular expression does not give the same
>result as 2-6.
>
>(This is simplified from something I'm working on. The answer may be
>trivial, but I don't see it)
>
>TIA,
>Patrick Vrijlandt
>
>import re
>
>data = """1234567890
>abcdefghij
>1234567890"""
>
>def mymatch(pattern):
>    mo = re.match(pattern, data)
>    print mo,
>    try:
>        print mo.groups()
>    except AttributeError:
>        print
>
>
>mymatch('.*\\n.*\\n.*')
>mymatch('(.*)\\n(.*)\\n(.*)')
>mymatch('(.{10})\\n(.{10})\\n(.{10})')
>mymatch('(\d{10})\\n([a-z]{10})\\n(\d{10})')
>mymatch(r'(\d{10})\n([a-z]{10})\n(\d{10})')
>mymatch(r'\n'.join([r'(\d{10})', r'([a-z]{10})', r'(\d{10})']))
>mymatch(r'\n'.join([r'(\d{10})|([a-z]{10})', r'([a-z]{10})', r'(\d{10})']))

You forgot to put () to limit your | operands. Correct version:

mymatch(r'\n'.join([r'(?:(\d{10})|([a-z]{10}))', r'([a-z]{10})',
   r'(\d{10})']))

(if I understood your intention correctly)

My problem is more complex:

  ...
  File "./prepares.py", line 64, in repl
    return self.search_re.sub(self.prep_replace, text)
  File "/usr/lib/python2.1/sre.py", line 164, in _sub
    return _subn(pattern, template, string, count)[0]
  File "/usr/lib/python2.1/sre.py", line 179, in _subn
    m = c.search()
RuntimeError: maximum recursion limit exceeded

As always:

import re   # sre
re.match('^START(.+?)END$', text, re.M|re.S)

And I grew so accustomed to .expand() already :-(

I need to call GhostBusters somewhere ;-)

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Thursday, September 06, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "How many weeks are there in a light year?" _/

From aahz at panix.com  Sun Sep 30 13:50:14 2001
From: aahz at panix.com (Aahz Maruch)
Date: 30 Sep 2001 10:50:14 -0700
Subject: Near Final PEP 247 - API for Cryptographic Hash Functions
References:  <3dofnztka2.fsf@ute.cnri.reston.va.us> <9p23f1$dj2$1@panix3.panix.com> <3dite3t7pu.fsf@ute.cnri.reston.va.us>
Message-ID: <9p7m0m$m6q$1@panix3.panix.com>

In article <3dite3t7pu.fsf at ute.cnri.reston.va.us>,
Andrew Kuchling   wrote:
>aahz at panix.com (Aahz Maruch) writes:
>>
>> How about flipping Tim's suggestion around and making the string
>> argument keyword based?
>
>What exactly does that mean?

new([string=])
new(key,[string=])
-- 
                      --- Aahz  <*>  (Copyright 2001 by aahz at pobox.com)

Hugs and backrubs -- I break Rule 6                 http://www.rahul.net/aahz/
Androgynous poly kinky vanilla queer het Pythonista   

We must not let the evil of a few trample the freedoms of the many.

From b_lamy at club-internet.fr  Mon Sep 17 02:15:46 2001
From: b_lamy at club-internet.fr (LAMY Bertrand)
Date: Mon, 17 Sep 2001 08:15:46 +0200
Subject: problem with extending python with C
Message-ID: <3BA59512.A59B33EF@club-internet.fr>

[PS : thanks for the last answer, there was a perfidious bug in my
code...]

now I've got another problem. I got a segfault at the end of my program,
after python has destroyed all the objects (I know that because I've put
a printf in the dealloc functions. so this is not very important since
it crashes only at termination). I got the segfault in that case :
- I've got 2 type object defined in C (if 1 of the 2 is defined in
Python, it won't crash) : one is a carrier which a Pyobject* (given at
creation, the carrier Py_INCREF the PyObject given and Py_DECREF it at
deallocation), the second is a carried (handled by the carrier of course
:)
- The carrier have an attribute that return the carried
- After creating a carrier containing a carried, I ask the carrier to
print the object carried

Some precisions :
- I don't have 100% crashes
- it seems that the crash occurs only when sizeof(carried) >= 40
- I have Python 2.2a3 and work under Linux

I've done the minimal code to get the crash, if someone is interested
(?), I can send it (I cannot manage to send the file attached with this
mail, sorry)

This bug is quite strange and I wonder if my code is responsible or not
?

thanks

-Blam

From ignacio at openservices.net  Mon Sep 10 16:50:19 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Mon, 10 Sep 2001 16:50:19 -0400 (EDT)
Subject: smtp.sendmail read receipt?
In-Reply-To: 
Message-ID: 

On 10 Sep 2001, Scott Nadeau wrote:

> I'm trying to figure out how to get a read receipt when a recipient
> has read an e-mail that my program is sending.  I've searched the web
> for the answer, but I can't seem to find it.  This is my current
> (working) code...

  http://www.rfc-editor.org/rfc/rfc1891.txt

-- 
Ignacio Vazquez-Abrams  

From stuart at bmsi.com  Wed Sep 26 12:51:59 2001
From: stuart at bmsi.com (Stuart D. Gathman)
Date: Wed, 26 Sep 2001 12:51:59 -0400
Subject: Embeding Python & Dynamic Callbacks
References: <916a2aab.0109260249.318d156f@posting.google.com>
Message-ID: <9ot13e$4od$1@nntp1-cm.news.eni.net>

In article <916a2aab.0109260249.318d156f at posting.google.com>, "Paul Tate"
 wrote:

> I can dynamically create the method table, but I cannot dynamically
> create a C callback function.  If I use the same callback for each
> dynamically loaded function, I do not know how to find out which token
> caused the callback to be called.

idea 3 - allocate a callable extension type for each dynamic C function.
The extension object contains whatever the common callback function needs
to know to find the dynamic C function.  Put the callable types in the
module dictionary along with the direct methods - even for C code loaded
*after* initializing the module.

-- 
Stuart D. Gathman 
Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flamis acribus addictis" - Mozart background
song for the Microsoft "Where do you want to go from here?" commercial.

From loki at cs.usyd.edu.au  Wed Sep  5 19:39:41 2001
From: loki at cs.usyd.edu.au (Loki Patrick)
Date: Thu, 06 Sep 2001 09:39:41 +1000
Subject: Parsing Python question (newbie)
Message-ID: <3B96B7BD.2DB00D0D@cs.usyd.edu.au>

Hi, I've been toying with writing a parser (in Python) for Python.
Has someone already done this?

A .py to .pyc compiler would be nice. I know there is some kind
of parser generator written in C bundled with Python, but
does it produce recursive descent parsers, or table driven?
I'd prefer recursive descent for reasons of readability.

Any help would be appreciated.

Loki

From deltapigz at telocity.com  Sat Sep 29 17:24:57 2001
From: deltapigz at telocity.com (Adonis Vargas)
Date: Sat, 29 Sep 2001 17:24:57 -0400
Subject: Threads + Enviroment Variables
Message-ID: 

im having problems accessing enviroment variables from within a thread; the
error im am getting is an 'undefined' error, but the variables i definded
but in a module-level.
i.e.

-- in module something.py --
something = []

-- in script --
from something import * # import the variable 'something' right?

def somefunction(somevalue):
    return somevalue+=1

def somethreadedfunction():
    for i in range(10):
        something = somefunction(0) # boom. an 'undefined' error???
        print something

Thread(target=somethreadedfunction).start()
--

now this is not the real code im working on; since the code im working on is
very complex i chose not to paste it; just provided the general idea of what
i am trying to accomplish, therefore the code provided could not be correct.

any help would be greately be appreciated.

Adonis

From aleax at aleax.it  Fri Sep 14 05:43:31 2001
From: aleax at aleax.it (Alex Martelli)
Date: Fri, 14 Sep 2001 11:43:31 +0200
Subject: Newbie:  Why Does This Work This Way...Global Variables And The Signal Module....
References: 
Message-ID: <9nsjg4023kd@enews2.newsguy.com>

"Ignacio Vazquez-Abrams"  wrote in message
news:mailman.1000434075.23039.python-list at python.org...
    ...
>     e=select.select([sys.stdin], [], [], 0)
    ...
> There's no reason why it couldn't catch another character if the select()
> function returns on any keypress, which it doesn't seem to on Linux :/

That strictly depends (assuming sys.stdin isatty) whether the
tty is in raw or cooked mode (and details of said mode).

Alex

From aleax at aleax.it  Fri Sep  7 10:24:12 2001
From: aleax at aleax.it (Alex Martelli)
Date: Fri, 7 Sep 2001 16:24:12 +0200
Subject: newbie: cannot import name error
References:  <3B98D4F6.445C1525@engcorp.com>
Message-ID: <9nalad0unl@enews1.newsguy.com>

"Peter Hansen"  wrote in message
news:3B98D4F6.445C1525 at engcorp.com...
    ...
> On the other hand, you're trying to do something I've _never_
> needed to do yet, after almost two years with Python.  Any time
> (to date) I've needed to install an extension, I've been okay
> with just copying it to the python/lib folder, or with adding

Then maybe you use a platform for which precompiled C extensions
are easier to come by than for Solaris, and have never needed to
build your own (because the distutils are the easiest way to
build C extensions anyway).

Alex

From jtdubs at eos.ncsu.edu  Mon Sep 10 01:05:43 2001
From: jtdubs at eos.ncsu.edu (Justin Dubs)
Date: Mon, 10 Sep 2001 01:05:43 -0400
Subject: large class hierarchies in python
References:  <9ner16$sbt$1@uni00nw.unity.ncsu.edu> <7934d084.0109091703.6414e22a@posting.google.com>
Message-ID: <9nhhn5$g1o$1@uni00nw.unity.ncsu.edu>

Thank you for the suggestions.

I have already taught myself the basics of Prolog, Postscript and Lisp.  I
will look into the rest of them though.  I am trying to expose myself to all
of the various unique methods of programming for the purposes of eventually
designing one of my own also for purely theoretical and curiosity-based
reasons.

In order of abstraction, starting at the lowest is obviously assembler.  I
know that for both x86 up through Pentium as well as the basics of motorola
assembler.

Above that I have C.

Above that I have C++, Objective-C, Pascal, Basic as well as more visual
languages such as Visual BASIC, Visual C++, Java and TCL and FoxPro.

Above that I have Perl, Python.

Above that I have Prolog, Lisp.

Also, more miscellaneously, HTML, Javascript, VBScript, SQL and Shell
scripting and a little of postscript and smalltalk.

I"ll dive into Haskell/Forth/Miranda/APL and see what I like.  I also want
to do a little Scheme and Eiffel at some point.  Thanks a lot for the
suggestions.

Do I appear to be missing any categories of languages?  I have the basic OO,
Functional, Scripting languages covered, I think.  Thanks again guys,

Justin Dubs

From loewis at informatik.hu-berlin.de  Tue Sep 18 13:31:16 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 18 Sep 2001 19:31:16 +0200
Subject: nntplib and xover
References: 
Message-ID: 

rickp at telocity.com (Rick Pasotto) writes:

> Some news servers return the Xref: line in response to the XOVER
> command. Currently the nntplib does not include this line.
> 
> 1) Will this be included in future versions?
> 2) What is the best way to get this line now?

I'd recommend to use the .xover method of the NNTP class. Guido's time
machine at work?

Regards,
Martin

From slgrph at icehouse.net  Fri Sep 14 16:01:29 2001
From: slgrph at icehouse.net (Shirley)
Date: Fri, 14 Sep 2001 13:01:29 -0700
Subject: DataComPro Needs Typists/Compilers
Message-ID: <130280-22001951420129780@icehouse.net>

Home Typists Needed!!!!

We are looking for a few dependable people who desire an earning of 
substantial income right in the comfort of their homes. We need local 
compilers to secure and type our exclusive mailing lists in nearly every 
city of the country and we are not about to open thousands of offices 
nationwide. That is why we need YOU! We appreciate your assistance, so we 
do our very best to make it easy for you. Simply follow our instruction 
kit and hand written names and addresses come to you every day and all 
you have to do is submit them for your pay of $3.00 for each and every 
name and address you compile and type! Paychecks are mailed on the 1st 
and 15th each month! 

NEW BONUS SYSTEM NOW ADDED! After submitting 100 names to BestBizUsa, 
you will now be paid $4 per name! Also, we now have weekly bonuses set 
up !!

Do not confuse this one of a kind offer with any unwanted commissioned 
mailing programs, envelope stuffing, or any other such deceptive 
nonsense. This is legitimate home employment that is not a get rich quick 
job, but you can make a part time income fairly easily.

Working with BESTBIZUSA Typing Resource Centers gives you the freedom 
to stay at home and create your own hours. If you are a parent with 
children, this type of work is very beneficial because it allows you to be 
a stay at home parent. These are only a couple of the perks, let's not 
forget the money. The more time you put into this job, the more you 
will get out of it. Because we need local typists immediately, we will 
hold your position open for the next 10 working days. So if you would like 
to begin working and making money, email me at 
slgrph at icehouse.net 
for more information

Your email address was part of a purchased list and I
believe you are someone interested in Internet Business
Opportunities.  If I received your e-mail in error, or
you are no longer interested, click here to be removed.
Be sure REMOVE is in the Subject Title and you will not
be contacted again:

From gerson.kurz at t-online.de  Fri Sep  7 02:55:40 2001
From: gerson.kurz at t-online.de (Gerson Kurz)
Date: Fri, 07 Sep 2001 06:55:40 GMT
Subject: py2dll ?
Message-ID: <3b986e2c.72980718@news.isar.de>

Is there something like py2exe, that generates DLLs ? 

I've embedded the best programming language in the world, Python, to
my existing C application. Actually, I start up a python-powered
webserver, with fixed scripts. Currently, I use PyRun_SimpleFile() for
this; it would be great if it were possible to generate a DLL from the
scripts and call this instead. 

In my rather simpleminded viewpoint, this should more or less only
mean changing main.exe to main.dll, and exporting a standard function
from it, right ?

From boyd at insultant.net  Tue Sep 25 00:08:46 2001
From: boyd at insultant.net (Boyd Roberts)
Date: Tue, 25 Sep 2001 06:08:46 +0200
Subject: Why so few Python jobs?
References:  <3BAF5062.FC4F00D3@hotmail.com>  
Message-ID: <9op06b$shl$1@neon.noos.net>

"David B Terrell"  a ?crit dans le message news: slrn9qvh1s.lfl.dbt at pianosa.catch22.org...
> David Terrell            | "Instead of plodding through the equivalent of
> Prime Minister, NebCorp  | literary Xanax,

nah, xanax's name is alprazolam :)

From rickf at glacier.jpl.nasa.gov  Wed Sep 26 19:31:07 2001
From: rickf at glacier.jpl.nasa.gov (Rick Forrister)
Date: Wed, 26 Sep 2001 16:31:07 -0700
Subject: timegm() equivalent function in Python?
Message-ID: <3BB2653B.A5A2DE10@glacier.jpl.nasa.gov>

Working on converting a collection of perl utilities I've written for
projects to Python.  Am encountering a problem in time conversions; we
need to process date strings from a YYYY-MM-DDTHH:MM:SS.SSSSSZ format
(Zulu time = GMT = UTC) into unix epoch date format.  time module does
not list function which takes as input a time tuple and returns UTC
based epoch time.  Is there such a module out there somewhere?

Parsing the string from the ascii format mentioned above into date &
time chunks is no problem of course, split handles that quite nicely. 
It's the conversion from a UTC based tuple set -> epoch time value that
I need.

Appreciate
     rickf
-- 
"The best we can hope for concerning the people at large is that they be
properly armed."
        -- Alexander Hamilton, The Federalist Papers at 184-188

From jblazi at hotmail.com  Thu Sep 20 14:22:57 2001
From: jblazi at hotmail.com (Janos Blazi)
Date: Thu, 20 Sep 2001 20:22:57 +0200
Subject: Best book on Python?
References: <9oasom$pit$1@plutonium.btinternet.com>
Message-ID: <3baa3411_3@news.newsgroups.com>

I have read "Learning Python" by Mark Lutz and after glancing through it for
an afternoon I could start working in the evening. I still think that the
material is very well chosen and the presentation is precise and enjoyable.
So in my opinion it is the best book on Python. My other Python book is
"Python and Tkinter Programming" by John Grayson and though it contains a
lot of information, virtually everything you need to use Tkinter, I wish he
would give more explanations instead of examples.

J.B.

-----=  Posted via Newsfeeds.Com, Uncensored Usenet News  =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
 Check out our new Unlimited Server. No Download or Time Limits!
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From s713221 at student.gu.edu.au  Tue Sep 18 22:00:31 2001
From: s713221 at student.gu.edu.au (Joal Heagney)
Date: Wed, 19 Sep 2001 12:00:31 +1000
Subject: Direct TK interface
References: <2764949.5mLc6kNg2l@lunix.schabi.de>
Message-ID: <3BA7FC3F.D21E3A95@student.gu.edu.au>

Markus Schaber wrote:
> 
> Hi,
> 
> I was just wondering whether it is possible (and worth in sense of
> speed etc.) to directly interface TK into python (without using the TCL
> interpreter inbetween).
> 
> markus

Don't know if this is what you want, but you can look up Rivet in the
Vaults.
-- 
      Joal Heagney is: _____           _____
   /\ _     __   __ _    |     | _  ___  |
  /__\|\  ||   ||__ |\  || |___|/_\|___] |
 /    \ \_||__ ||___| \_|! |   |   \   \ !

From logiplexsoftware at earthlink.net  Fri Sep  7 17:21:02 2001
From: logiplexsoftware at earthlink.net (Cliff Wells)
Date: Fri, 7 Sep 2001 14:21:02 -0700
Subject: Creating Excel files on Linux
In-Reply-To: 
References: <3B97A39C.6A5234D7@olen.to>  
Message-ID: <01090714210205.02565@logiplex1.logiplex.net>

On Friday 07 September 2001 13:16, you wrote:
>
>
> Yes, poor little innocent IBM.  The same company that till recently was
> known for a monnolithic culture stangling in neckties and suits.  The fact
> that Gates took them for a ride is a reflection of their own idiocy and
> their stunning lack of vision.
> have a good wekend all,
> Maan

Yep, they have been/are a lot of suits.  Nevertheless, they have _always_ had 
a tradition of being extremely fair with their business partners and Gates & 
Co took advantage of _that_.  Had IBM dealt with Gates the way Gates deals 
with his business "partners", IBM would have owned DOS and Microsoft would be 
but a small footnote in PC history.

It's more like the idiocy and stunning lack of vision of the average PC user, 
who choose MS on a daily basis.  The vision of MS provided us with 16-bit 
OS's for a decade after the introduction of the 386.   It also provided us 
with the petri dish for hundreds of VBA macro viruses.  Wasn't part of their 
vision also to "replace" the Internet with MSN?

Besides, I never suggested anything about "poor little" IBM.  Since you 
missed the point, I will expound: I was referring the fact that they are 10 
times the size of Microsoft (I'm not referring to the nonsense of the stock 
market, but actual employees/revenue, etc) and are investing 1 billion this 
year to Linux development and promotion.

Have a very nice weekend.

-- 
Cliff Wells
Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 x308
(800) 735-0555 x308

From SBrunning at trisystems.co.uk  Fri Sep 21 04:47:39 2001
From: SBrunning at trisystems.co.uk (Simon Brunning)
Date: Fri, 21 Sep 2001 09:47:39 +0100
Subject: Converting tuples to dictionaries?
Message-ID: <31575A892FF6D1118F5800600846864D78C1C1@intrepid>

> From:	Mart van de Wege [SMTP:mvdwege.usenet at drebbelstraat20.dyndns.org]
> Apologies if this turns out to be a FAQ, but I couldn't find it in the
> standard
> docs and the books I own on how to do it. So without further ado, I'll
> state
> the question:
> 
> I have some data in an SQL database. Now AFAICT psycopg (aka pythonDB 2.0
> for
> PostgreSQL) returns the query results as a list of tuples. The data that
> returns from my query would fit very well in a dictionary, ie. tuple[0]
> would
> be the key, and the rest would make the value (or list of values), in fact
> the
> conceptual model I have for my program would *need* a dictionary to
> process.
> 
> Now the obvious way to turn a list of tuples into a dictionary would be to
> loop
> over the list and convert them by assigning tuple[0] to be the key and the
> rest
> of the tuple the value. Slightly more efficient would be to define a
> function
> that does that with one tuple and then map the function on the list.
> 
> The question is, is this really the only way to go about that, or am I
> barking
> up the wrong tree entirely? It really seems like a brute force approach to
> me.
> Is there an alternative?

Marc-Andr? Lemburg's mxTools ()
includes a dict function which does *almost* what you want...

Cheers,
Simon Brunning
TriSystems Ltd.
sbrunning at trisystems.co.uk

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reliance on it, is prohibited and may be unlawful. TriSystems Ltd. cannot
accept liability for statements made which are clearly the senders own.

From dalke at dalkescientific.com  Fri Sep 21 22:33:49 2001
From: dalke at dalkescientific.com (Andrew Dalke)
Date: Fri, 21 Sep 2001 20:33:49 -0600
Subject: To re or not to re ... ( word wrap function?)
References: <3BABBDFA.456B4B45@home.net> 
Message-ID: <9ogt5n$tjp$1@slb6.atl.mindspring.net>

Skip Montanaro:
>I've been using this to format text for a long time.  It runs on a 1.5.2
>system so it doesn't use string methods or any 2.0+ syntax.

Another Python implementation I've seen (not tested) is Andrew
Kuchling's 'tex_wrap', which implements the line break method
used by TeX.

http://www.amk.ca/python/code/tex_wrap.html

                    Andrew
                    dalke at dalkescientific.com

From duncan at NOSPAMrcp.co.uk  Tue Sep 25 09:37:58 2001
From: duncan at NOSPAMrcp.co.uk (Duncan Booth)
Date: Tue, 25 Sep 2001 13:37:58 +0000 (UTC)
Subject: Why so few Python jobs?
References: <200109250603.f8P63W014851@hera.cuci.nl> 
Message-ID: 

"Carlos Gaston Alvarez"  wrote in
news:mailman.1001409027.8458.python-list at python.org: 

>     ?Python? Arguments againts it (from the boss himself) was that it
>     was an 
> internet language and that he was told that it was going to disapear in
> a few years. So I toll him that it was not true. And even if he had to
> rewrite it in some years he would have saved money (because of
> prototiping). 

There is a very good point here. The last few times I have had to write 
something in C/C++ I have written it first in Python to get it all working 
and then (when necessary) written a C/C++ version based on the Python code.

My experience is that this results in a shorter development time, and 
better code, than writing in straight C/C++. Of course usually you can get 
the time even shorter by skipping the conversion to C/C++ and just shipping 
the Python version.

-- 
Duncan Booth                                             duncan at rcp.co.uk
int month(char *p){return(124864/((p[0]+p[1]-p[2]&0x1f)+1)%12)["\5\x8\3"
"\6\7\xb\1\x9\xa\2\0\4"];} // Who said my code was obscure?

From breakfast at 10.am  Thu Sep 27 14:07:11 2001
From: breakfast at 10.am (mallum)
Date: Thu, 27 Sep 2001 19:07:11 +0100
Subject: file find module
In-Reply-To: <20010927203054.N25063@phd.pp.ru>
References: <20010927172051.B1120@10.am> <20010927203054.N25063@phd.pp.ru>
Message-ID: <20010927190711.B364@10.am>

on Thu, Sep 27, 2001 at 08:30:54PM +0400, Oleg Broytmann wrote:
>    ...you can easily write your own using os.path.walk(), anf glob (or
> fnmatch).

aha ! This looks like just whats needed - thanks :)

    -- mallum

From mr.murray at mindspring.com  Tue Sep  4 00:04:52 2001
From: mr.murray at mindspring.com (Andrew Murray)
Date: Mon, 3 Sep 2001 21:04:52 -0700
Subject: Quick Correction
References: <9n1jdn$ads$1@slb3.atl.mindspring.net>
Message-ID: <9n1jn7$ps$1@slb3.atl.mindspring.net>

Grrrr....
Please read:
    dataMembers = append(myOtherClass("hello from # " + str(i))
As:
    dataMembers.append(myOtherClass("hello from # " + str(i))
"Andrew Murray"  wrote in message
news:9n1jdn$ads$1 at slb3.atl.mindspring.net...
> Hi,
>
> I'm looking into writing some types in C for use in a Python program
> I'm working on. I've been reading and it looks really easy (especially
> with SWIG) to create a simple type in C for use in python, but does
anybody
> know
> how (or can point me to a good reasource on how) to create a type in C
> whose data members would be other types written in C? For instance, if I
> wanted to recreate this (ficticious) type:
>
> Class myClass():
>     dataMembers = []
>     def __init__(self, integer_input):
>         i=0
>         while(i < integer_input):
>             dataMembers = append(myOtherClass("hello from # " + str(i))
>     def printMessages(self):
>         for member in self.dataMembers:
>             member.printMessage()
>
> Class myOtherClass():
>     message = ''
>     def __init__(self, string_input):
>         self.message = string_input
>     def printMessage(self):
>         print self.message
>
> I hope this example is clear... Please advise
>
> Thanks,
>
> Andrew Murray
>
>

From johnroth at ameritech.net  Sun Sep 30 08:39:20 2001
From: johnroth at ameritech.net (John Roth)
Date: Sun, 30 Sep 2001 05:39:20 -0700
Subject: Justifying text.
References: <3BB55DEC.67F78190@yahoo.com> <9p4hjr$h2v$1@neon.noos.net> <9p54ga$loj$1@tyfon.itea.ntnu.no> <9p5fib$q7r$1@hadron.noos.net> <9p5uln$4o9$1@tyfon.itea.ntnu.no> <9p69ah$daf$1@neon.noos.net> <3BB6D7EE.D87FAF00@yahoo.com>
Message-ID: 

"A.A"  wrote in message
news:3BB6D7EE.D87FAF00 at yahoo.com...
> I've really messed up: IN short, I just wanted to write a program in
> python that justified plain text in a .txt to a specified margin.

Justification is not difficult. There are a number of approaches, depending
on what you want to do. If the text is already properly split into
lines, see the .ljust, .rjust and .center string methods. If it isn't,
then you need to break it into lines. There may be easier methods,
but I use a simple loop, scanning backwards from the maximum
line length until I hit white space.

The following may do what you want:

# translate MS Word text format with no line breaks to 80 character
# line output. Each paragraph is presumed to be a single input line.

import sys

def ltDriver(fnIn, fnOut):
    inFile = open(fnIn, "r")
    outFile = open(fnOut, "w")
    for line in inFile.readlines():
        i = 0
        if line[-1] == '\n': line = line[:-1] + " "
        while i < len(line):
            j = min(i + 80, len(line) - 1)
            while j > i and not line[j].isspace(): j -= 1
            while j > i and line[j].isspace(): j -= 1
            outFile.write(line[i:j+1] + "\n")
            i = j + 1
            while i < len(line) and line[i].isspace(): i += 1

if __name__ == "__main__":
    ltDriver("B1I14Attack.txt", "B1I14Attack2.txt")

John Roth

From rnd at onego.ru  Thu Sep 20 00:48:45 2001
From: rnd at onego.ru (Roman Suzi)
Date: Thu, 20 Sep 2001 08:48:45 +0400 (MSD)
Subject: New Python WebMail app
In-Reply-To: 
Message-ID: 

On Thu, 20 Sep 2001, Aaron Fransen wrote:

>The scuttlebutt is that some future version of Mozilla (near? far?) will
>support some kind of rich-text editing function, and whether that will be
>IFRAME or not is anyone's guess...except the developers of Mozilla of course
>:)

If I understand Mozilla team, they are sticking to standards, not to what
Microsoft add. So, if IFRAME has the semantics you mention, it will be
done. If it will not be in the standard, then it most probably will not
be.

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Thursday, September 20, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "A big enough hammer fixes anything" _/

From qrczak at knm.org.pl  Mon Sep 10 09:42:03 2001
From: qrczak at knm.org.pl (Marcin 'Qrczak' Kowalczyk)
Date: 10 Sep 2001 13:42:03 GMT
Subject: functional vs procedural list comprehension
References:  <3B9954A7.12E97C21@home.net>  
Message-ID: 

Mon, 10 Sep 2001 10:15:14 GMT, Peter Dobcsanyi  pisze:

> The current semantics can be described (using the last example) as:
[...]
> In contrast, a functional listcomp's semantics would be:
[...]

It's the same.

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZAST?PCZA
QRCZAK

From qrczak at knm.org.pl  Sun Sep  9 12:17:47 2001
From: qrczak at knm.org.pl (Marcin 'Qrczak' Kowalczyk)
Date: 9 Sep 2001 16:17:47 GMT
Subject: Proposed PEP for a Conditional Expression
References: 
Message-ID: 

Sun, 09 Sep 2001 09:42:49 -0500, Michael Chermside  pisze:

> Included in this email is a PEP which I am putting together dealing with 
> the idea of introducing a conditional expression into Python. I would 
> welcome any discussion, suggestions, and/or help, sent either to this 
> newsgroup under this topic, or emailed to me at .

IMHO very well done!

> I prefer the syntax of SPEC_2, but am certainly open to other ideas.

Me too.

>      SPEC_4: Use "if c: a else: b".
>          The following production would be added to Python syntax:
>              expression: "if" expression ":" expression "else" ":"
>                          expression
>          The famous "dangling-else" problem would NOT arise because
>          the "else:" part would be mandatory.
> 
>          PRO - [might allow "if c1: a elif c2: b else: c"]
>          CON - [elif thing would re-introduce dangling else problem]

It would not introduce dangling else. You can replace 'elif' with
'else: if', it's unambiguous.

You couldn't do that in 'if' statement without introducing an
indentation level, which is why 'elif' exists in the first place.
'if' expression doesn't use indentation so having 'elif' there is
not that important.

The fact that there is always an 'else' makes it possible to
distinguish between 'if' statement and 'if' expression if somebody
cares (there shouldn't be any need for distinguising these). The
'if' statement really looks like two statements, split before 'else',
so there is no overlap in syntax.

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZAST?PCZA
QRCZAK

From jknapka at earthlink.net  Wed Sep  5 06:01:48 2001
From: jknapka at earthlink.net (Joseph Andrew Knapka)
Date: Wed, 05 Sep 2001 10:01:48 +0000
Subject: overriding tks text insert method
References:  <3B936093.929DEA42@earthlink.net> <01090512113900.22018@pmm19>
Message-ID: <3B95F80C.E5641D2C@earthlink.net>

Christof Ecker wrote:
> 
> Hi Joseph,
> 
> thanks for your comments. I have been playing with your code yesterday and I
> discoverd an additional problem:
> what I need is to execute a cleanup procedure AFTER text has been inserted or
> deleted. If you override Tks default binding by an input handler routine, the
> handler will be executed BEFORE the default binding.
> 
> This is because, the default bindings are bound to the text class, whereas the
> "user"-bindings are bound to the class instrance and have therefore higher
> priority and are therefore executed first.
> 
> Any idea ?

If you bind to  instead of  you should get
the release events after the insert has occurred.

Cheers,

-- 
# Joe Knapka
# "You know how many remote castles there are along the
#  gorges? You can't MOVE for remote castles!" - Lu Tze re. Uberwald
# Linux MM docs:
http://home.earthlink.net/~jknapka/linux-mm/vmoutline.html

From tim.one at home.com  Sat Sep  8 23:23:11 2001
From: tim.one at home.com (Tim Peters)
Date: Sat, 8 Sep 2001 23:23:11 -0400
Subject: PyArg_ParseTuple O format semantics
In-Reply-To: 
Message-ID: 

[Tim]
> News to me, and I see nothing about that in the CVS log.  The only 2.0.1
> patch to getargs.c plugged a memory leak in vgetargskeywords(); it was
> leaving the refcounts on names of keyword arguments too high,
> when iterating over a keyword dict.

[Robin Becker]
> I guess that might be it. I suppose if anyone had taken action to correct
> the memory leak then when it was fixed --> 2.0.1 then their extra DECREF
> would be wrong.

Yes, that would cause problems indeed.  BTW, the Subject line was
misleading, because this really has to do with PyArg_ParseTupleAndKeywords,
and is specific to the "keywords" part of that.  And I was incorrect in
saying it left the refcount on the name of the keyword arg too high -- it
actually left the refcount on the returned object too high.

If you believed the docs and treated the return value as a borrowed
reference, then you used to have a memory leak and don't anymore.  It's
probably rarely a serious leak, else the bug wouldn't have gone undetected
for so long (years).  Here's the original patch that fixed it:

http://mail.python.org/pipermail/python-checkins/2000-December/014550.html

in response to this October 2000 bug report:

http://sf.net/tracker/?group_id=5470&atid=105470&func=detail&aid=219862

From jbranthoover at yahoo.com.NOSPAM  Fri Sep 14 15:00:59 2001
From: jbranthoover at yahoo.com.NOSPAM (John Branthoover)
Date: Fri, 14 Sep 2001 19:00:59 GMT
Subject: Newbie:  Why Does This Work This Way...Global Variables And The Signal Module....
References: 
Message-ID: 

Hey thanks Ingacio,
    This works great.  Pressing enter is much better than CTRL C.  I don't
know much about the select(),  but I read  in another article that it is a
line orientated device.  The articled told how to put it into a charter mode
using TERMOIS and termios modules.  Unfortunately I do not have access to
the termios module.  I would like to have an "any key" function.

    I am basically a hardware guy and I am in the process of writing
checkout software for a board that I have designed.  The Python installation
that I am working with was ported over by one of our software engineers.  I
had him look into getting ncurses to compile but after a half of a day he
gave up.  He has more important issues to deal with than getting me access
to pretty colors, windows and other curses goodies.  Which he does.  I have
Linux installation at home and have played with the Python curses module and
I know what I am missing.

    Any way thanks again for your help......

"Ignacio Vazquez-Abrams"  wrote in message
news:mailman.1000434075.23039.python-list at python.org...
> On Fri, 14 Sep 2001, John Branthoover wrote:
>
> >     OK,  that makes sense.  Is there not away to define a global
variable
> > once for all of the functions in the module?
>
> Nope. At least not that I know of.
>
> >     Or better yet,  is there a better way to break out of a endless
loop.
> > The loop will display some values continuously.  I want to be able to
get
> > out of this loop and go back to a main menu.  I am working on an Lynx
box
> > (not Linux) with no GUI or even curses support.
>
> The following will run until you press enter:
>
> ---
> import sys, select
>
> def run():
>   while 1:
>     e=select.select([sys.stdin], [], [], 0)
>     if not e==([], [], []):
>       c=sys.stdin.read(1)
>       if c=='\n':
>         break
>     print "You can't catch me, I'm the gingerbread man!"
>
> run()
> print "D'oh! You caught me!"
> ---
>
> There's no reason why it couldn't catch another character if the select()
> function returns on any keypress, which it doesn't seem to on Linux :/
>
> Also, if you can put a termcap/terminfo into the Lynx box, you may be able
to
> get (n)curses working.
>
> --
> Ignacio Vazquez-Abrams  
>
>
>
>

From loewis at informatik.hu-berlin.de  Fri Sep 14 08:56:47 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 14 Sep 2001 14:56:47 +0200
Subject: Namespace confusion
References: <9nssgi$oiv$1@news.netcologne.de>
Message-ID: 

Luna Tic  writes:

> I get an error message certainly because of the interdependence of
> those two modules, am I right?

Indeed. Your problem slightly varies depending on whether you attempt
to import foo or bar. Suppose your application does "import foo".
Then you get the following sequence of events

1. import foo. an empty foo is added to sys.modules, which gets
   filled as execution of foo progress
2. foo executed import bar. bar is added to sys.modules, and
   execution of bar starts.
3. bar performs import foo, and gets a reference to the module
   whose initialization is in progress.
4. class bacon is defined; initialization of bar completes.
5. initialization of foo resumes, defining class foo
6. i = foo() is executed, but in substeps: first, the right-hand
   side is executed, then the assignment is performed, so:
6a) a foo.foo instance is created
 b) its __init__ is invoked, performing bar.bacon()
 c) a bar.bacon() instance is created
 d) its __init__ is invoked, performing foo.i.list.append
    At this time, neither foo.i is assigned, nor does the object
    that would be assigned have a list attribute yet.

If your application starts with "import bar", it does not get that far:

1. import bar. Add bar to sys.modules.
2. performs import foo. Add foo to sys.modules
3. inside foo: import bar; obtain reference to bar
4. define class foo.foo
5. perform i = foo()
5a) create foo.foo instance
 b) call its __init__, referring to bar.bacon.
    Class bacon has not yet been defined.

If your main program is "python foo.py", you are in more troubles:
foo.py will define the module __main__, not the module foo. So the
import foo will load a second copy of foo. If that is your problem,
you should avoid having global variables in the __main__ module; write
a separate application script instead.

To avoid the problem in the second run, delay imports as much as
possible:

# foo.py
class foo:
    def __init__(self):
        import bar
        self.attr = bar.bacon()
        self.list = []

i = foo()

# bar.py
class bacon:
    def __init__(self):
        import foo
        foo.i.list.append(1)

Now, importing bar will do nothing but create a class bacon; foo will
be imported only when a bacon instance is created. Importing foo will
still run into the problem that i is not assigned. To avoid this, you
have to rearrange the constructors. Here are a couple of options:

A. Delay setting of attr
# foo.py
class foo:
    def __init__(self):
        self.list = []

i = foo()
import bar
self.attr = bar.bacon()

# bar.py
class bacon:
    def __init__(self):
        import foo
        foo.i.list.append(1)

B. Delay appending bacons

# foo.py
class foo:
    def __init__(self):
        import bar
        self.list = []
        self.attr = bar.bacon()

i = foo()
i.attr.register()

# bar.py
class bacon:
    def register(self):
        import foo
        foo.i.list.append(1)

C. register into different variable

# foo.py
class foo:
    def __init__(self):
        import bar
        self.attr = bar.bacon()
        self.list = []

i_list = []
i = foo()
i.list = i_list

# bar.py
class bacon:
    def __init__(self):
        import foo
        foo.i_list.append(1)

I don't know what you problem you are really trying to solve; it seems
you'd be better of with less cyclic structures.

Regards,
Martin

From peter at engcorp.com  Wed Sep 12 23:43:48 2001
From: peter at engcorp.com (Peter Hansen)
Date: Wed, 12 Sep 2001 23:43:48 -0400
Subject: Locating Relative Resource Files
References: <3B9FC419.42BADEE4@bgb.cc> 
Message-ID: <3BA02B74.AE351A0D@engcorp.com>

Gordon McMillan wrote:
> 
> Don Garrett wrote:
> 
> >   Is there some way to determine the location of the file from which
> > the currently executing source was loaded? Or the file/directory of
> > the initial python script?
> 
> os.path.dirname(sys.argv[0]) should do it (although it may be '',
> meaning os.getcwd() is the script's directory).

I think this is close to being a FAQ.  The last time it came up,
I think we settled on:

   os.path.abspath(sys.argv[0])

Looking at abspath() in the module index, it says on most platforms
it is equivalent to os.path.normpath(os.path.join(os.getcwd(), <>))
If sys.argv[0] specifies an absolute path, that expression just
returns sys.argv[0].  If it is relative, it is converted to absolute
by joining with the current directory.

-- 
----------------------
Peter Hansen, P.Eng.
peter at engcorp.com

From jh at web.de  Mon Sep 17 13:05:42 2001
From: jh at web.de (J�rgen Hermann)
Date: Mon, 17 Sep 2001 19:05:42 +0200
Subject: [ANN] PIRXX 1.1
Message-ID: <9o5afl$d06$03$1@news.t-online.com>

This is the first release of PIRXX, a wrapper of Xerces and Xalan
for Python. Currently, it contains a working SAX2 driver for the
Xerces parser.

What's missing is the locator mechanism, and the DTDHandler and
EntityResolver interfaces.

Homepage:
    http://pirxx.sourceforge.net/

Download:
    http://sourceforge.net/project/showfiles.php?group_id=25711

Mailing list:
    http://mail.python.org/mailman/listinfo/xml-sig

From cprinos at foliage.com  Thu Sep  6 09:09:40 2001
From: cprinos at foliage.com (Chris Prinos)
Date: 6 Sep 2001 06:09:40 -0700
Subject: Change in IE COM behavior
Message-ID: 

I had for some time been using the win32com.client package to control
MS Internet Explorer, but recently have seen a change in it's
behavior. What used to happen is that each time I called
win32com.client.Dispatch('InternetExplorer.Application') I would get a
new instance of the browser.

Now when I do it, I get attached to the topmost _existing_ browser
window (could be an IE window, or an explorer window). Subsequent
calls attach to the same instance, rather than creating new ones. It
is probably some recent installation/update that caused this, but I'm
not sure where to start looking... has anyone seen this before?

I'm running Python 2.1 (ActiveState build 211) with win2k (latest
service pak applied) and IE 5.5.

Chris

From comments at cygnus-software.com  Thu Sep 27 02:34:08 2001
From: comments at cygnus-software.com (Bruce Dawson)
Date: Thu, 27 Sep 2001 06:34:08 GMT
Subject: scanf style parsing
References: <3BB16A50.BAE082FE@cygnus-software.com> 
Message-ID: <3BB2C7DA.F63EEAA7@cygnus-software.com>

Wow! Great answers. And incredibly fast.

Thanks to all.

Rather than the long and complicated PEP route of adding scanf
style functionality to Python it would probably be enough to just add some
more examples to the Python regexp documentation. I searched the Python
documentation for scanf() and I looked at the regexp documentation, so if
it had contained the examples in this reply or others I would have done
my parsing properly long ago. For Perl hackers it is easy to figure out
regexp, but for us old C/C++ types, it's *tough*

Then again, I *always* say that the documentation is the problem...

Thanks again.

Richard Jones wrote:

> On Wednesday 26 September 2001 15:42, Bruce Dawson wrote:
> > I love programming in Python, but there are some things I have not found
> > the easy way to do.
>
> That's what we're here for :)
>
> > I understand that Python is supposed to be good at
> > text parsing, but I am having trouble with this simple task. Given this
> > text (the output from VisualC++) I want to find out how many errors and
> > warnings there were:
> >
> > smtpmail.exe - 0 error(s), 0 warning(s)
> >
> > In C/C++ that would be something like:
> > sscanf(buffer, "smtpmail.exe - %d error(s), %d warning(s)", &errors,
> > &warnings);
> >
> > It's not that I think the sscanf syntax is particularly elegant, but it
> > sure is compact! I saw the discussion about adding scanf to Python
> >
> > http://mail.python.org/pipermail/python-dev/2001-April/014027.html
> >
> > but I need to know what people do right now when faced with this task.
>
> Right now, people use regular expressions, which are more flexible that
> sscanf, but don't do the type conversions (everything comes out as a string)
> and are a little more verbose, code-wise.
>
> [richard at ike ~]% python
> Python 2.1.1 (#1, Jul 20 2001, 22:37:24)
> [GCC 2.96 20000731 (Mandrake Linux 8.1 2.96-0.58mdk)] on linux-i386
> Type "copyright", "credits" or "license" for more information.
> >>> import re
> >>> scan = re.compile(r'smtpmail.exe - (\d+) error\(s\), (\d+) warning\(s\)')
> >>> result = scan.match("smtpmail.exe - 0 error(s), 0 warning(s)")
> >>> errors, warnings = map(int, result.groups())
> >>> errors
> 0
> >>> warnings
> 0
> >>>
>
> ... or something similar. The RE can be made more flexible to allow, eg. the
> non-existence of the ", %d warning(s)" part:
>
> >>> scan = re.compile(r'foo.exe - (\d+) error\(s\)(, (\d+) warning\(s\))?')
> >>> result = scan.match("foo.exe - 0 error(s)")
> >>> result.groups()
> ('0', None, None)
> >>> result = scan.match("foo.exe - 0 error(s), 0 warning(s)")
> >>> result.groups()
> ('0', ', 0 warning(s)', '0')
>
> ... and so on...
>
>      Richard

From thomas.heller at ion-tof.com  Tue Sep 25 15:53:23 2001
From: thomas.heller at ion-tof.com (Thomas Heller)
Date: Tue, 25 Sep 2001 21:53:23 +0200
Subject: COMServer thru Py2Exe question !!
References: <8f8ffe67.0109251142.43246129@posting.google.com>
Message-ID: <9oqnbk$egujt$1@ID-59885.news.dfncis.de>

"Sunit Joshi"  wrote in message news:8f8ffe67.0109251142.43246129 at posting.google.com...
> Hello COM Gurus:
>
> I have a small problem: I can get VB6 to instantiate a PyCom object
> created thru py2exe. However each time I try to create the COM Server,
> a DOS window flashes for a second, I guess because of the line
> D:\PROGRA~1\TestCom\testCom.exe {3882ECFF-3B74-4444-BB47-BDC2285CEB95}
> where the testCom.exe is run.
>
> Is there any way of getting rid/minimizing the DOS window ??
>
> thanks
> Sunit
Simply build with the -w (or --windows) command line flag
to suppress the DOS box:

python setup.py py2exe -w

Regards,

Thomas

From aleaxit at yahoo.com  Sun Sep  9 04:19:04 2001
From: aleaxit at yahoo.com (Alex Martelli)
Date: Sun, 9 Sep 2001 10:19:04 +0200
Subject: Very elementary help in using Python on Windows 98
References: <3b98e582.0@news.acay.com.au>
Message-ID: <9nf8kr02jam@enews4.newsguy.com>

Jeff Melvaine wrote:

> I have begun to experiment with Python on Win98 on my personal laptop. 
> When I set up a script xxx.py and double click the icon to run it, I get a
> window (presumably some kind of debugging console)which lasts for a few
> seconds,
> flashes a message and dies instantly so I can't read it.  There is
> evidently a problem in my script somewhere, but how can I get the window
> to hang around long enough to see what it is?

Suppose your script is very well organized: only def and class statements 
first, including a def main statement creating a function named main, then 
at the end a statement such as:

if __name__=='__main__':
        main()

If so, then the only thing you need is to turn this last statement into:

if __name__=='__main__':
        try: main()
        finally: raw_input("Press Enter to terminate")

try/finally is a precious statement: the finally clause is executed no 
matter how the try clause terminates -- be it "normally", or because of an 
exception.  It's normally used to ensure some needed finalization.  In an 
environment which makes your console window disappear on termination, such 
as running a Windows program by double-clicking on an icon, you can look at 
this explicit "wait half a sec before closing the console" as a needed 
finalization.  On some Windows platforms you can set a console's properties 
to "no auto-closing" depending on the shortcut reached to open it, but I'm 
not sure this is available on Win98 nor how exactly to go about it -- it's 
not a Python question anyway, but a Windows one.

If your code is not as well organized as this, you can still use 
try/finally (all you have at top level now can be indented 4 spaces and go 
inside the try clause), although it would be worth taking the occasion to 
enhance program organization as well.

> When I start up the Python interpreter in its own window, it doesn't seem
> to
> know where my script is.  Do I need to set a path variable somewhere to
> tell

Not the way python.exe works today, alas: rather you have to give 
python.exe the complete path to your script (followed by arguments to the 
script, if any).  The SUBST command of COMMAND.COM, while old and rusty, 
sometimes comes in handy for that sort of stuff.

> I would probably find this much easier in Linux (given my experience on
> Unix stations at work, where writing much more complex scripts (even in
> Perl :) poses no real problems), but for an application running on this
> machine and reading data dumped from Excel and other Windows based
> applications, that is not an easy way for me to go.

You could consider Cygwin -- it's a good bash shell and a faithful 
imitation of as many aspects of Linux as Cygnus/RedHat could possibly fit 
into it -- you can also get an XFree86 port for Cygwin (comes with a lousy 
old window manager, twm, but once you have Cygwin and X read it's a snap to 
download tgz's, e.g. for WindowMaker, building it on Cygwin is no harder 
than ./configure, make, make install -- very much as it would be on Linux). 
Cygwin comes with a Python 2.1.1 port in the contrib directory, but I'm not 
sure if the latter does COM or can use win32all (I'd guess not) -- no 
problem, you can run Windows-native Python under Cygwin anyway, and still 
get the advantages of bash & good commandline tools.

Alex

From adina_levin at mindspring.com  Sat Sep 22 12:42:26 2001
From: adina_levin at mindspring.com (adina_levin at mindspring.com)
Date: Sat, 22 Sep 2001 11:42:26 -0500
Subject: newbie question: converting integer to string
Message-ID: <9oifr8$and$1@slb5.atl.mindspring.net>

I would like to convert a variable, which represents an integer, to a
string.

To convert an integer to a string, one simply encloses the string in quotes.

e.g.
>>> '42'
'42'

But how do you do this if the integer is represented by a variable?

>>> num=42

how can I generate a string representation of num?

Thank you very much,

- Adina

From samschul at pacbell.net  Tue Sep 18 20:16:47 2001
From: samschul at pacbell.net (Samuel Schulenburg)
Date: 18 Sep 2001 17:16:47 -0700
Subject: bitwsie operator help please
References:  
Message-ID: 

grante at visi.com (Grant Edwards) wrote in message news:...
> In article , David In VA wrote:
> > I am not sure how to properly write the bitwise operator but I think it 
> > will be useful for some thing I need to do.  If I want to print "Hello" 
> > if the value 2^2 (4) is in a given value (lets say testvalue) how would 
> > I do this?  I have been trying this
> > 
> > if  4 & testvalue:
> > 	print "hello"
> 
> It works for me.  How exactly is it not working?

Works for me also. I let testvalue = 8, and if failed, I then let
testvalue = 12, and it printed "hello"

Sam Schulenburg

From woodm at equire.com  Thu Sep  6 15:02:30 2001
From: woodm at equire.com (Matthew D. Wood)
Date: Thu, 06 Sep 2001 13:02:30 -0600
Subject: Function to merge sorted lists
References: 
	 <3B8F1BE0.6060108@erols.com> <87r8tkb51x.fsf@complete.org>
Message-ID: <3B97C846.10101@equire.com>

Would it be faster to use the list.pop command?  I doubt it, but then 
again, I'm always surprised.

John Goerzen wrote:

> "Edward C. Jones"  writes:
> 
>> Here is a Python program that does the same thing:
> 
> 
> There's a more straightforward way to do it:
> 
> def merge(l1, l2):
>     ret = []
>     l2c = 0
>     for item in l1:
>         while l2c < len(l2) and l2[l2c] < item:
>             ret.append(l2[l2c])
>             l2c += 1
>         ret.append(item)
>     return ret + l2[l2c:]
> 

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From aleax at aleax.it  Mon Sep 17 07:27:29 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 17 Sep 2001 13:27:29 +0200
Subject: Getting all possible combinations of list items
References:  <3ba594dd$0$330$6e49188b@news.goldengate.net> 
Message-ID: <9o4mn102mdn@enews4.newsguy.com>

"Martin von Loewis"  wrote in message
news:j4g09mdvvt.fsf at informatik.hu-berlin.de...
> "Greg Krohn"  writes:
>
> > scratching my head over 'magic' code,
>
> I prefer explicit loops over map and lambdas:

So do I, but building up a large string (here, the one
in the variable called number) by +'ing small ones in
a loop is a disaster.  So, I'd make a small mod here:

> def magic_algorithm(another_list, count):
>     length = len(another_list)
>     result = []
>     for i in xrange(length**count):
>         number = ''
change this line to:
          number = []
>         for pos in range(count):
>             # prepend the next digit
>             number = another_list[i % length] + number
change this line to:
              number.append(another_list[i % length])
>             i = i / length
>         result.append(number)
change this line to:
          number.reverse()
          result.append(''.join(number))
>     return result

The number.reverse() line may not be needed if the
SET of strings returned, rather than their order,
is what one is after, as is typically the case.

I think it would be even clearer if we avoided the
inner loop in favour of a clearer one, i.e.,
rewriting the whole thing for clarity:

def magic_algorithm(another_list, count):
    length = len(another_list)
    result = []
    for i in xrange(length**count):
        number = []
        for dig in digits_in_base(i, length, count):
            number.append(another_list[dig])
        result.append(''.join(number))
    return result

where, e.g. and still emphasizing clarity:

def digits_in_base(value, base, ndigits):
    result = ndigits*[0]
    i = ndigits-1
    while value and i>=0:
        result[i] = value%base
        value /= base
        i -= 1
    return result

With this auxiliary function at hand we may also
rewrite magic_algorithm using list comprehension,
e.g. for the inner loop only:

def magic_algorithm(another_list, count):
    length = len(another_list)
    result = []
    for i in xrange(length**count):
        result.append(''.join([another_list[dig]
            for dig in digits_in_base(i, length, count)]))
    return result

or for both loops:

def magic_algorithm(another_list, count):
    length = len(another_list)
    return [''.join([another_list[dig]
        for dig in digits_in_base(i, length, count)])
            for i in xrange(length**count)]

but either or both of these might be considered as
over-application of the list comprehension form,
depending of course on one's attitude to list
comprehension form itself.  Personally, I prefer
the penultimate one, because it seems to me that
the last one is hard to follow -- it's unusual to
have a list comprehension inside another list
comprehension, after all.  But there's not much to
choose among them except personal taste issues:-).

Alex

From chrishbarker at home.net  Wed Sep 12 18:17:52 2001
From: chrishbarker at home.net (Chris Barker)
Date: Wed, 12 Sep 2001 15:17:52 -0700
Subject: references/pointers in Python?
References: <20010912194833.B30374@simba>  <20010912210927.A30757@simba> <01091212060600.09769@logiplex1.logiplex.net> 
Message-ID: <3B9FDF10.9BF06240@home.net>

Anton Lavrik wrote:

> You are right! I'v already found one wonderfull solution for the
> problem. Actually references were not the only way for making it.
> But anyway, I can't understend why such powerfull Perl-like references
> haven't been implemented in Python.

Maybe becasue they aren't neccesary, as your example shows!

What was you application, anyway...enquiring minds want to know!

-Chris

-- 
Christopher Barker,
Ph.D.                                                           
ChrisHBarker at home.net                 ---           ---           ---
http://members.home.net/barkerlohmann ---@@       -----@@       -----@@
                                   ------@@@     ------@@@     ------@@@
Oil Spill Modeling                ------   @    ------   @   ------   @
Water Resources Engineering       -------      ---------     --------    
Coastal and Fluvial Hydrodynamics --------------------------------------
------------------------------------------------------------------------

From t at chabry.caltech.edu  Thu Sep 27 01:51:33 2001
From: t at chabry.caltech.edu (Titus Brown)
Date: 26 Sep 2001 22:51:33 -0700
Subject: Are there 'Interfaces' in Python??
References: <9orb19$ba6$1@slb6.atl.mindspring.net>  <9ot405$3bo$1@chabry.caltech.edu> 
Message-ID: <9ouep5$8qc$1@chabry.caltech.edu>

In article ,
Tim Hammerquist  wrote:
>Me parece que Titus Brown  dijo:
>>
>> [ munch of my claim "lack of interfaces sometimes bad, ==>
>>                     "interfaces sometimes good" ]
>> 
>> I would rather regard this as neutral & a convenience for people writing
>> code that uses file-object-like-things.  It's certainly not a convenience
>> for people writing new classes that attempt to emulate the behavior of
>> already-existing objects with unclear definitions, and it sure would be
>> nice to have the option of some type checking built into the language,
>> but I understand why it's not there and appreciate the convenience.  But
>> there are downsides too...
>
>This sounds like one of the many threads in c.l.smalltalk. :)
>
>If you want to use interface-style type checking, the following might
>work for you:
>
>class MyInterface:
>    # define
>
>class MyIFClass1(MyInterface):
>    # implement
>
>class MyIFClass2(MyInterface):
>    # implement
>
>class MyIFException(Exception, MyInterface):
>    # implement and extend
>
>and use isinstance(obj, MyInterface) to see if it implements it.

Well heeeeck, I can write an inheritance based type checker any hour of
the day, but if the language libraries don't support it, then you're
half pissin' into the wind, aren't you...

>It doesn't survive someone deleting keys from the o.__dict__ attribute,
>but Python's run-time nature precluded that long ago, didn't it?

;)

--titus, who loves programming in Python but wishes that there were even MORE
	nice, simple solutions to complex problems.

From jockmack at hotmail.com  Sun Sep  2 05:57:46 2001
From: jockmack at hotmail.com (Jock Mackenzie)
Date: 2 Sep 2001 02:57:46 -0700
Subject: wxpython
Message-ID: <7592d940.0109020157.5e3212e7@posting.google.com>

I have been learning python/wxpython & have written a small program in
wxpython that asks for input from the user  [using the function
wxGetNumberFromUser()] then applies a formula and produces a long integer as
a result.  I want to display the resulting number from the calculation on
the wxFrame or wxPanel or in a dialogbox. I cannot find a function for doing
this. Most message boxes only want to return a string not a long integer as
I want.
How do you do this??
thanks in advance
regards Jock.

From massmail at lb.bcentral.com  Sun Sep  9 17:50:46 2001
From: massmail at lb.bcentral.com (Anonymouse)
Date: 9 Sep 2001 21:50:46 -0000
Subject: �������,������� ���������,����� ���������.
Message-ID: <1000072246.60987.qmail@ech>

                  ????????? ???????!

	        ??? ????? ?????????? ?   
?????????? ? ??? ??????, ?????????, ?????, ???????????.
??? ??????? ???????????, ??? ?????????.

	??? ??????-?? ?????????? ??? ??????????????? ????? ??????????? ? ????? ?? ???? ???????? ?????? ???????????? ??? ????????????, ?????, ????????, ?????????? ? ?. ?., ?????? ????? ????, ??? ???? ?? ????? ???????????? ???? ????????????, ??????? ?????????? ??? ??????. 
	????????? ???????? ?????? ? ???????? ??????????????? ? ???????????? ?? ?????? ? ??????, ?? ? ?? ???????, ?? ????? ??????????? ????????? ???? ?????? ???????? ????? ? ? ?????????? ?????.
	?????? ????? ???????????? ???????? ?????. 
        ??? ??????? ???????????, ?????? ?? ?????? ???????? ????????, ??????????, ?? ? ????????? ????????????? ??? ?????????????, ??? ? ?????????? ?????????????? ??????????? ???????. ??? ????? ????? ??? International Rectifier, Epcos, Bourns, Metex, unit-t ? ??.
        ??? ??????? ??????????????- ????????? ?????????, ??????-????, ??????, ???????, ?????, ????? ? ?.?.
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        ??? ??????? ????????- ? ????????? ????? ?? ???????????? ?????????? ??????????? ???????? ???????-?????? ??????????.

      ? ?????? ???????? ?????????, ???????????? ????? ??????,?? ??????? ???????????? ?? ????? ????? ? ????????:
		     vielm.narod.ru

   ?????????? ?? ?????? ????? ????? ????????? ??????????? ? ??????????????????.
    ?? ?? ?????? ?????????????  ??????????, ??? ????? ??????? ?????? ??? ?????????, ?? ???? ???????? ??? ?????????? ????? ?? ???????? ??? ??? ????? ? ? ?????????? ???????? ?????.
    ???? ??????????? ?  ????????? ?????????????? ?? ????? ?????, ?? ?????? ????????? ?? ??? ????:  (095)  275-89-94, ??? ?? ??????????? ?????: tandiv at mail.ru .
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      ?? ???? ???????? ?? ?????? ?????????? ?? ?????????: 275-89-94, 746-68-78.

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From frandebo at latt.if.usp.br  Sat Sep 22 16:09:21 2001
From: frandebo at latt.if.usp.br (Francisco Borges)
Date: Sat, 22 Sep 2001 17:09:21 -0300
Subject: google and Python ;-)
In-Reply-To: <3BACEB9B.5341552E@engcorp.com>; from peter@engcorp.com on Sat, Sep 22, 2001 at 03:50:51PM -0400
References:  <3BACEB9B.5341552E@engcorp.com>
Message-ID: <20010922170921.A8018@latt.if.usp.br>

? Peter Hansen wrote:

> > We all know that Python could be characterised as
> > readable, powerful, dynamic programming language
> > 
> > Guess, which languages google user will find by
> > using those keywords ;-)
> > 
> > And how many hits will contain "Python".
> 
> I get 11700 hits from 
> http://www.google.com/search?hl=en&q=readable+powerful+dynamic+programming+language
> and 1580 hits from 
> http://www.google.com/search?hl=en&q=readable+powerful+dynamic+programming+language+python

 http://www.google.com/search?hl=en&q=readable+powerful+dynamic+programming+language+perl
 Will give you  3550 hits...

 http://www.google.com/search?hl=en&q=readable+powerful+dynamic+programming+language+tcl
 1,970 hits

 http://www.google.com/search?hl=en&q=readable+powerful+dynamic+programming+language+Smalltalk
 1.300 hits

 http://www.google.com/search?hl=en&q=readable+powerful+dynamic+programming+language+ruby
 258 hits

> Not sure what that means... that Python constitutes only 13.5% of
> readable, powerful, dynamic programming languages?

  No, that probably has more to do with the amount of people that are
  marketing python this way, which is indirectly connected with the
  amount of people using Python, but there should be (?are?) better ways
  to estimate that.

  Peace.
-- 
   Francisco.
   S?o Paulo, Brasil.

From brian.smith at thr.ca  Fri Sep 21 12:01:51 2001
From: brian.smith at thr.ca (Brian)
Date: 21 Sep 2001 09:01:51 -0700
Subject: tkFileDialog and Multiple Filetypes
Message-ID: <1984df93.0109210801.8c00851@posting.google.com>

I haven't been able to turn up an example of specifying more than one
file type per line.e.g

n=askopenfilename(filetypes=[("Image Files","*.jpg;*.gif"),
                             ("JPEG",'*.jpg'),
                             ("GIF",'*.gif'),
                             ('All','*')])

This results in a TCL error. I don't want to select multiple files, I
just want to display multiple types. Is there a way of doing this?

Thanks in advance.

From charles at a3a.com.br  Wed Sep  5 16:29:30 2001
From: charles at a3a.com.br (Charles)
Date: Wed, 5 Sep 2001 16:29:30 -0400
Subject: SocketServer
Message-ID: <01090516293000.23511@magneto>

Hello
Anybody know where ca i find a good tutorial or 
examples to create a Socket Server ?

Regards
Charles

From rnd at onego.ru  Thu Sep  6 07:06:53 2001
From: rnd at onego.ru (Roman Suzi)
Date: Thu, 6 Sep 2001 15:06:53 +0400 (MSD)
Subject: out of memory
In-Reply-To: <008d01c136c2$84fcf450$a500a8c0@GASTON>
Message-ID: 

On Thu, 6 Sep 2001, Carlos Gaston Alvarez wrote:

> What happens when python runs out of memory?
> Is there an exception?

>>> a=range(10000000)
Traceback (most recent call last):
  File "", line 1, in ?
MemoryError

> Where are exceptions documented?

In the Python Documentation, of course.

> Chau & tia,
> 
> Gaston

Sincerely yours, Roman A.Suzi
-- 
 - Petrozavodsk - Karelia - Russia - mailto:rnd at onego.ru -

From rnd at onego.ru  Sat Sep  8 08:47:55 2001
From: rnd at onego.ru (Roman Suzi)
Date: Sat, 8 Sep 2001 16:47:55 +0400 (MSD)
Subject: Creating Excel files on Linux
In-Reply-To: <20010908133602.M18172@phd.pp.ru>
Message-ID: 

On Sat, 8 Sep 2001, Oleg Broytmann wrote:

>Hello!
>
>   Completely offtopic. Sorry, I cannot resist. Well...
>
>On Fri, Sep 07, 2001 at 11:04:37AM -0500, Maan M. Hamze wrote:
>> living in.  I am not defending Microsoft here, but I am being realistic.
>
>   In you realism you said many bad words about people and companies. I
>don't want to be that kind of "realist". I want to be an idealist. Only
>idealists can change the world. Realists seems to be slaves of the status
>quo. (I am not flaming you, don't take it personnaly.)

Probably, the better word is "conformist". It is always easier to be
conformists (unless revolution happens ;-)

And being non-conformist requires personal sacrifices: I can't apply for
grants because they require me to fill Word & Excel forms. (And it turned
out that Word documents created by StarOffice crush/hung MS Office 2002
mercilessly.) So, if MIcrosoft monopoly will last, my non-conformistic
views will make me non-conformic with the whole society, because I will
not be able to interface with state using free systems. For example, if I
had a firm, I *MUST* pay for at least MSDOS under which works the program
to prepare tax-reports! While such programs are probably just several
screens of Python code + database of classificators, etc.

The only hope is to convince gov's to use free software as happens in the
West.

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Saturday, September 08, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "Aren't cats just widdle furry balls of love?" _/

From tim.one at home.com  Wed Sep 26 00:36:29 2001
From: tim.one at home.com (Tim Peters)
Date: Wed, 26 Sep 2001 00:36:29 -0400
Subject: Cygwin Python -- Thread or not to thread...
In-Reply-To: <1001462689.4303.8.camel@lifelesswks>
Message-ID: 

[posted & mailed]

[Tim]
> 2. See Include/thread_nt.h in the Python source distribution for the
>    native Windows "Python lock" support.  It uses the Win32
>    InterlockedXXX APIs, not Mutex or even CriticalSection.  It's very
>    efficient (but it's not trying to emulate pthreads, just Python
>    locks), has been used in high-stress contexts for years on all
>    flavors of Windows, and has no known (or even suspected) bugs.

[Robert Collins]
> Sounds to me like that is the appropriate mechanism to use under cygwin
> as well. The caveats about not using win32 direct functions only apply
> where other unix semantics and behaviour are still expected. The
> Interlocked calls cannot block, and therefore will not interfere with
> signals. They access process address space memory and will therefore
> work with fork().

I expect you'd have to examine the source for compatibility with what you're
doing to emulate signals and fork (which the native Win32 port ignores
entirely, for the obvious reason).

The InterlockedXXX stuff is a layer around Win32 CreateEvent +
WaitForSingleObject + (auto-reset) SetEvent, avoiding calls to the latter
two when there's no actual contention.  InterlockedCompareExchange is
simulated with a kind of spin loop on Win95, which lacks that function.
That's about all there is to it.

> You may well need to reset the value after fork() manually, as cygwin
> cannot do that for native win32 calls.

The Python C API defines a PyOS_AfterFork() function, which platforms can
fill with whatever crud they need to do after a fork.  On all platforms to
date, it calls (in both parent and child) PyEval_ReInitThreads(), and resets
the Python signal module's notion of what the current pid is.  However,
mixing threads with fork is a frigging mess on the best of platforms, and it
generally takes a bona fide platform expert to guess what happens in the
end.

> This is taking your assertion as face value :}... InterlockedXXX are
> faster still than Criticalsections+win32 events (which is how condition
> variables are emulated).
>
> BTW: I am assuming that under linux condition variables are used - is
> that correct?

Yes, a Python lock under pthreads is implemented via a combination of a
flag, a pthread_mutex_t and pthread_cond_t.

From heikowu at ceosg.de  Wed Sep  5 20:17:03 2001
From: heikowu at ceosg.de (Heiko Wundram)
Date: Thu, 6 Sep 2001 02:17:03 +0200
Subject: ANN: CGIgen 0.1-alpha-1
Message-ID: <01090602170300.27146@phoenix>

Hello fellow Pythoneers,

I have just finished installing CGIgen on SourceForge, and have released an 
early alpha-version of the code.

CGIgen is basically a library that aims at extending what Zope calls a 
namespace: Contrary to Zope it doesn't offer a "flat" namespace, but rather a 
namespace that can be arbitrarily deep, and at each level has a namespace in 
the Zope sense.

Making the long statement short: it implements a tree-structure.

Each item in the tree is accessed through a name, whereby names that are 
added later override names that were placed earlier, thus creating 
polymorphism.

The basic classes that organize just this (Container, Data and Callback) are 
finished.
Two demo-classes that use these classes as bases and implement real 
functionality are also included in the current version: SessionData 
implements a session data handler that integrates smoothly into the tree, and 
VariableData is a handler that integrates a text-file with a special 
formatting into the tree.

What is also finished is an exception-handling scheme especially adapted to 
CGI-developers: Exceptions that are raised somewhere in the program can be 
logged to a file, and each exception has a certain severity which specifies 
when to log it (the lower the severity, the more severe the exception is, 
thus this is basically a log-level).

CGIgen will be extended to cover much more tasks that are frequent in 
CGI-development (such as user-databases, document templating, etc.), but this 
should be enough announcement for tonight.

The project is under the Python License (although the source doesn't state 
that... yet ;)).

If anyone is interested in joining the effort, don't hesitate to mail me. :)

Project URL: http://sourceforge.net/projects/cgigen/.

Don't rely on the CVS, the data in there is older than the release; I still 
have some problems with getting the data from my local CVS into the 
sourceforge.net CVS (I don't have a permanent Internet connection, and thus 
can't use the sourceforge.net CVS for all checkin-operations).

-- 
Yours sincerely,

	Heiko Wundram
	Head of the Celle Open Source Community
		(CEOSG - Celler Open Source Gemeinde)

PS: The current release still contains .pyc files; I forgot to remove them 
before tarring the archive... Please forgive me! ;)

From aleax at aleax.it  Fri Sep  7 12:57:39 2001
From: aleax at aleax.it (Alex Martelli)
Date: Fri, 7 Sep 2001 18:57:39 +0200
Subject: Nested scopes: why is it weird?
References: <3B98F3B0.53AC2524@swiftview.com>
Message-ID: <9nauag01nj2@enews2.newsguy.com>

"Scott Long"  wrote in message
news:3B98F3B0.53AC2524 at swiftview.com...
> Nested scopes seem like a nice addition (of course!) but there are some
> weird things about it. Take a look:

Not really, just a typical misunderstanding (which also existed
wrt global variables before nested scopes).

> Right, this is what you would expect. But how about this?
>
> >>> from __future__ import nested_scopes
> >>> def a():
> ...   def b():
> ...     k = x
> ...     x = 0

The x name in procedure b is LOCAL -- the compiler knows it,
because x is re-bound in b's scope.  (Incidentally, you can
never rebind a name from a lexically-nested local scope
in your scope; you CAN rebind a global name, if you use the
global statement at the start of a function).

> My first beef here is, why is the exception called UnboundLocalError?

Because x is a local name, and it is not yet bound when it is
first used in b's first instruction.

> The variable is certainly bound (into the local scope), it simply has

Nope.  x is a local name, but not bound to any value, as yet.
Only the assignment statement (if it was executed) would bind
name x (to the value 0).

> not been assigned. Why not call it UninitializedLocalError? I know it
> isn't going to change, I'm just asking.
>
> But my main concern is that this way of selecting a binding seems very
> unintuitive. Shouldn't the first statement referencing x be the
> statement that specifies the binding of x? In this case, shouldn't "k =

*In general*, how could the compiler tell what the first statement
IS, that _references_ name x within a given scope?  Assuming you
mean, "first to execute".  The compiler _might_ assign some
arbitrary ordering, of course.  But having:
    if a>b:
        y=x
    else:
        x=y
have *TOTALLY* different semantics from:
    if b>=a:
        x=y
    else:
        y=x
when it SEEMS they're totally equivalent, would be truly weird, so
I don't think you mean "first in some arbitrary order (such as,
longest-first, or lower-line-number-first, or whatever)".

> x" cause x to get bound as a free variable, not a local to b()? I'm not
> claiming that this is a bug. I am curious as to why it was decided that
> things are going to work this way. It makes assignment to a variable in
> an enclosing scope impossible!

Yes, the latter is exactly Guido's decision: he has always maintained
that the right (aka obvious) way for something to keep and update
state is to define a class, rather than stretch closures to let code
in them re-bind things "partways up" -- or so I hear, and I sure
see his point.  But it's not any kind of necessary consequence of
Python's long-standing rules that all variables re-bound in a scope
are local to that scope unless explicitly mentioned in a global
statement -- it would have been trivial to say, for example, that
"global x in a" was THE way for b to inform the compiler that the
x name b uses and re-binds is the one in a, not one local to b itself
(somebody wanting to make closures really powerful/handy might have
stretched that to "global x in a as z":-).

Java just doesn't let a local variable 'shadow' one with the
same name from a lexically-outer scope, and that might have
been a nice choice too -- just forbid b to have a local variable
named x if a lexically-outer scope of b had a similarly named
local variable.  Unfortunately, this restriction, which I have
always liked, and proposed when nested scope were PEP'd, was
not accepted (though it did get a mention in the PEP), so we'll
live forevermore with misunderstandings on this point.

Alex

From nicolas at otelnet.com  Wed Sep 19 17:13:15 2001
From: nicolas at otelnet.com (Nicolas Duchastel)
Date: 19 Sep 2001 14:13:15 -0700
Subject: Embeded Multi-Threaded Python: PyEval_InitThread(), PyEval_SaveThread(),...
References: 
Message-ID: <8e0ac4fb.0109191313.5fef1454@posting.google.com>

Thanks for the quick response.... but.....

I actually RTFM-ed it; that's why my question is so detailed.
The doc seem to be conflicting in some areas and lacks some important
information.

For example, Chapter 8 states that Py_Initialized() can be called
before or after PyEval_InitThreads(); so which is best ? what are the
implications ? any nuance between these two ways ? any examples ?

Also, chapter 8.1 does indicated 4 different ways to do locking:
  C_Function_ToCallPythonCode()
  {
	PyThreadState* save = PyEval_SaveThread();	// LOCK
	PyImport_ImportModule( ...); // load another module
	PyRun_SimpleString(...);      // execute a 1 line of Python code
	PyPObject_CallMethod(....); // execute a full Python method
	PyEval_RestoreThread(save);		// UNLOCK
  }
OR
  C_Function_ToCallPythonCode()
  {
	PyEval_AcquireLock();	// LOCK
	PyImport_ImportModule( ...); // load another module
	PyRun_SimpleString(...);      // execute a 1 line of Python code
	PyPObject_CallMethod(....); // execute a full Python method
	PyEval_ReleaseLock();		// UNLOCK
  }
OR
  C_Function_ToCallPythonCode()
  {
	PyEval_AcquireThread(??);	// LOCK
	PyImport_ImportModule( ...); // load another module
	PyRun_SimpleString(...);      // execute a 1 line of Python code
	PyPObject_CallMethod(....); // execute a full Python method
	PyEval_ReleaseThread(??);		// UNLOCK
  }
OR
  C_Function_ToCallPythonCode()
  {
	Py_BEGIN_ALLOW_THREADS
		PyImport_ImportModule( ...); // load another module
		PyRun_SimpleString(...);      // execute a 1 line of Python code
		PyPObject_CallMethod(....); // execute a full Python method
	Py_END_ALLOW_THREADS
  }

So which one should I use ?

Also, image my 2 distinct thread B and C executing the 1st snipplet of
code above, if the call to PyObject_CallMethod() is VERY long and
takes ages,...
chapter 8 says

   "In order to support multi-threaded Python programs, the
    interpreter regularly releases and reacquires the lock --
    by default, every ten bytecode instructions."

Does that thus mean that a 2nd thread running this 1st snipplet
above will be interupted in the middle of its work in
PyObject_CallMethod() and another thread will have a go at it.
If so, what happens to the ThreadState object when the 2nd thread
calls PyEval_SaveThread() ? if it doesn't swap it, it will run with
the 1st thread's ThreadState object. If it does swap it, when this
2nd thread will also get interupted, won't the 1st thread get back
to run and thus it will run with the 2nd thread's object !?
I mean, I must be missing someting !?

Also, what about the things I was asking with regards to the actual OS
thread's ID ? i.e. does it matter that my code starts in one thread
and then works from another thread ? do I need to create ThreadState
objects for each threads ?

Thus,.. please RTFP (where P is for Posting rather than Manual)

Thanks,

Nicolas

Ignacio Vazquez-Abrams  wrote in message news:...
> On 19 Sep 2001, Nicolas Duchastel wrote:
> 
> > I am trying to use the Python/C API function to get an embeded Interpreter
> > into a multi-threaded C++ application. We are using Pthreads on Solaris 7.
> > My application works fine, but only with 1 thread; and then, when I stop it,
> > it core dumps.
> > I am using Python 2.1.1 built on Solaris 7 with the SUN's C++ 5.2 compiler.
> 
> http://www.python.org/doc/current/api/initialization.html
> http://www.python.org/doc/current/api/threads.html

From wqh-2 at 263.net  Tue Sep  4 04:50:52 2001
From: wqh-2 at 263.net (sdf)
Date: Tue, 4 Sep 2001 16:50:52 +0800 (CST)
Subject: =?gb2312?B?d2hhdCB0aGUgZGlmZmVyZW5jZSBiZXR3ZWVuIGFyYW5nZSgxMS4pIGFuZCBhcmFuZ2UoMTEp
Message-ID: <3B9495EC.06400@smtp>

An HTML attachment was scrubbed...
URL: 
-------------- next part --------------
>>> x=arange(11)
>>> x
array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10])

>>> x=arange(11.)
>>> x
array([  0.,   1.,   2.,   3.,   4.,   5.,   6.,   7.,   8.,   9.,  10.])
>>> 

       what is the function of dot follow the number.
     such as 0.      1.            2.

___________________________________________IP????????????????????????????????????? 

From fredrik at pythonware.com  Tue Sep  4 03:29:46 2001
From: fredrik at pythonware.com (Fredrik Lundh)
Date: Tue, 04 Sep 2001 07:29:46 GMT
Subject: 3-arg float pow()
References: 
Message-ID: 

Tim Peters wrote:
> I'm sure David knows all that.

yeah, but what about everyone else on this list?  am I the
only one here that didn't know this (okay, okay, I could've
looked it up somewhere if I really needed the info ;-)

From amuys at shortech.com.au  Sun Sep  9 21:03:37 2001
From: amuys at shortech.com.au (Andrae Muys)
Date: 9 Sep 2001 18:03:37 -0700
Subject: large class hierarchies in python
References:  <9ner16$sbt$1@uni00nw.unity.ncsu.edu>
Message-ID: <7934d084.0109091703.6414e22a@posting.google.com>

"Justin Dubs"  wrote in message news:<9ner16$sbt$1 at uni00nw.unity.ncsu.edu>...
> Also, can you suggest some other good OO languages to learn?  I know
> Objective-C, C++, Java, some Smalltalk and now Python.  What do you think of
> Eiffel, if anything?

I personally only ever have two reasons for learning another
programming language.  The first is naturally need, when my boss
needed me to do some "web-programming", I spent two days and learnt
Javascript.  The second is for what I refer to as mental hysterisis. 
The #1 trait I look for, and recommend in a new language, is "Will
this language permanantly change the way I think and program in the
other languages I use?".

So if you already know Obj-C, C++, Java, Smalltalk, and Python, I
would suggest it's probably time to experiment with something that
isn't imperitive-OO.  Prolog, Haskell, Miranda, Forth, Postscript,
APL, would all suggest themselves to me as possibles, but there are
others in this group better qualified to make suggestions.

Andrae Muys

(and then one day you finish a small 15kloc C program, grep it and
realise that you forgot to use any explicit loops, without trying. ;).

From richard at bizarsoftware.com.au  Tue Sep 18 03:01:53 2001
From: richard at bizarsoftware.com.au (Richard Jones)
Date: Tue, 18 Sep 2001 17:01:53 +1000
Subject: python 3D?
In-Reply-To: <3BA6EC29.43D2DDC7@club-internet.fr>
References: <20010915135120.19016.00000755@mb-mo.aol.com>  <3BA6EC29.43D2DDC7@club-internet.fr>
Message-ID: <01091817015323.01597@ike>

On Tuesday 18 September 2001 16:39, LAMY Bertrand wrote:
> > Is it going to be based on the existing work of PyOpenGL, Numeric, pygame
> > and PIL? They're the technologies I'm working with at the moment, and the
> > only problem I'm having is to try an understand the sheer scale of the
> > facilities at my disposal when they're combined :)
>
> Yes it will use PyOpenGL, PyGame and maybe the PIL. I don't think we
> will use Numeric since I have written the math functions we need in a C
> module. In fact actually I am working more on the C extensions to Python
> I need for Py3D

Excellent! Can't wait! (Numeric is a bit daunting... As I mentioned, I'm only 
just trying to come to terms with the sheer scale of the stuff available and 
how they can interact :)

    Richard

From greg at cosc.canterbury.ac.nz  Wed Sep 12 20:47:53 2001
From: greg at cosc.canterbury.ac.nz (Greg Ewing)
Date: Thu, 13 Sep 2001 12:47:53 +1200
Subject: Proposed PEP for a Conditional Expression
References:  <6qvgire4bk.fsf@abnoba.intevation.de> <9nk3jd$4lc$1@glue.ucr.edu> <9nnsa3$bjl$1@news.mathworks.com> 
Message-ID: <3BA00239.DECE6412@cosc.canterbury.ac.nz>

Bernhard Herzog  wrote:

>          if  else 

I find myself liking this. To me,

  x = a if something else b

reads much more smoothly than

  x = if something then a else b

Rainer Deyke wrote:
> 
> However, it would not fit well with list comprehensions that have a 'for':
> 
> [ if  for i in range(5)] # Syntax error
> [ for i in range(5) if  else ] # Syntax error
>                                          # and ambiguous intent

This can be remedied: give the conditional expression
a precedence lower than any existing operator (which I
think is a good idea anyway), and exclude this level of 
precedence from the iterated-over expression of a for loop.

"Terry Reedy" :

> I agree that the above is backwards.
>  if  else 

No! That sounds way too much like Forth!

-- 
Greg Ewing, Computer Science Dept, University of Canterbury,	  
Christchurch, New Zealand
To get my email address, please visit my web page:	  
http://www.cosc.canterbury.ac.nz/~greg

From peter at engcorp.com  Thu Sep  6 12:32:12 2001
From: peter at engcorp.com (Peter Hansen)
Date: Thu, 06 Sep 2001 12:32:12 -0400
Subject: Simple Newbie Question - (slightly OT)
References:   
Message-ID: <3B97A50C.7E20A2D9@engcorp.com>

Scott Long wrote:
> 
> Marcin 'Qrczak' Kowalczyk wrote:
> 
> >> What is the proper pronunciation for "Tuple"?
> 
> > This question has been asked here 6 weeks ago. It seems that there
> > is no simple answer, various people pronounce "tuple" differently.
> >
> 
> Quite true. Consider quadruple (quad-roo-pul) and quintuple (quin-tuh-pul).
> I say that as long as this difference exists, no one has any reason to
> argue about "tuple".

Heh heh!  Considering that I've always pronounced both quadruple and
quintuple with "oo" not "uh", I'd have to agree with the conclusion
you reach, if not the reason for it. :-)

(Note on dictionary.com the three ways of pronouncing quadruple
and the four for quintuple.  Hmmm... triple only has one 
pronunciation, so there goes my nascent theory about there
being N-1 ways to pronounce these words. Dang. ;-)

-- 
----------------------
Peter Hansen, P.Eng.
peter at engcorp.com

From yelled at yahoo.com  Sat Sep 29 20:13:14 2001
From: yelled at yahoo.com (Hoon)
Date: 29 Sep 2001 17:13:14 -0700
Subject: COM Question: VB cDate equivalent i Pythonwin
Message-ID: 

Hi,

  I am working with ActiveX control from Bloomberg. This control has
cDate, which is an optional argument. I attempted to use both
mxDateTime and pywintypes.Time(time.time()), the first give me back
wrong type msg and later actually crashes pythonwin with usual
memory+unintelligible win error msg. I included Gen_py output as well
as VB code and my attempt with Pythonwin.

Thanks for just reading it,
X2 if anyone can really figure this out,

Hoon,

Gen_Py output:---------------------

	def Subscribe(self, Security=defaultNamedNotOptArg,
cookie=defaultNamedNotOptArg, Fields=defaultNamedNotOptArg,
OverrideFields=defaultNamedOptArg, Overrides=defaultNamedOptArg,
Results=defaultNamedOptArg, Monitor=defaultNamedOptArg):
		"""method Subscribe"""
		return self._ApplyTypes_(0x1, 1, (24, 0), ((12, 1), (3, 1),
(12, 1), (12, 17), (12, 17), (16396, 18), (12, 17)), 'Subscribe',
None,Security, cookie, Fields, OverrideFields, Overrides, Results, 
Monitor)

VB Prog:---------------------

dtStart = CDate((Year(Date) - 1) & "/" & Month(Date) & "," &
Day(Date))
dtEnd = Date
aryFields(0) = 1376
For i = 0 To UBound(vSyms)
    sym$ = vSyms(i) & " Index"
    'sym$ = "IBM Equity"
    BlpData1.GetHistoricalData sym, _
                                i + 1, _
                                aryFields, _
                                dtStart, _
                                dtEnd
Next i

Python:---------------------
		#BLP.Subscribe(vSyms[i], i, aryFields, )
		#BLP.GetHistoricalData(vSyms[i], i, aryFields,
D.DateTime(2000,12,12).COMDate(), D.DateTime(2000,12,22).COMDate())
		#bt = pythoncom.MakeTime(time.time()-3000000)
		#et = pythoncom.MakeTime(time.time())
		bt = pywintypes.Time(time.time()-3000000)
		et = pywintypes.Time(time.time())
		print bt,et
		BLP.Subscribe(vSyms[i], i, aryFields, bt, et)
	BLP.Flush()

From sholden at holdenweb.com  Thu Sep 20 13:56:06 2001
From: sholden at holdenweb.com (Steve Holden)
Date: Thu, 20 Sep 2001 13:56:06 -0400
Subject: .NET and Python
References:  <9nettc$ce1$1@slb7.atl.mindspring.net>    <8nMm7.133116$n75.31959718@news4.rdc1.on.home.com>  <9ni0fi0vq0@enews1.newsguy.com>  <9nidl201j12@enews1.newsguy.com>
Message-ID: 

"Alex Martelli"  wrote in message
news:9nidl201j12 at enews1.newsguy.com...
> "Van Gale"  wrote in message
> news:l02n7.226503$%a.8841628 at news1.rdc1.sdca.home.com...
> >
> > "Alex Martelli"  wrote in message
> > news:9ni0fi0vq0 at enews1.newsguy.com...
> > > "Van Gale"  wrote in message
> > > news:g7%m7.226487$%a.8840828 at news1.rdc1.sdca.home.com...
> > >     ...
> > > > > I've looked into .NET and I hate to admit it, MS is
> > > > > become more right lately.
> > > >
> > > > Microsoft marketing literature and hype has *always* been right.
For
> > the
> > >
> > > I disagree: I find Microsoft's marketing abysmal in its field.  One
> >
> > Yeah, I didn't really express that well :)  I was really trying to say
> > something like with .NET, Microsoft is doing a good job of seeming
right.
> > That doesn't mean they actually are right (at this point).
>
> Oh, I see!  Well, I was surprised by the quality of the betas of
> the .NET Framework and Visual Studio .NET, considering they're
> betas -- the *rest* of the .NET "vision" strikes me as _very_
> dubious (no matter how well Passport is implemented, for example,
> the idea of a closed-source, single-point-of-failure service
> becoming crucial to the functioning of most or all of eCommerce
> strikes me as VERY bad from a technical viewpoint).
>
>
Yes, but it concurs well with Microsoft's approach to other technologies
where they missed the boat, the Internet being simply the largest and most
visible of those.

In the past Microsoft have used their size and wealth to buy technologies
they can't compete with, sometimes to integrate it with their own products
(e.g. FrontPage), sometimes to kill what would otherwise have been a
competitor.

Since they can't "buy" the Internet, they are proposing an entirely new
net-centric architecture which will ostensibly play with other platforms. If
the cross-platform support for .NET is as good as that for Internet Explorer
then I'll believe .NET is cross-platform when I see it.

Combine this with the usual smoke-and-mirrors injection from the marketing
depertments and you get the classic Microsoft FUD campaign. Those who are
heavily dependent on Microsoft architectures have to follow along as their
backwards compatibility is cut out from under them (Visual Basic, for
example, is being completely redefined as you know. This will make it a
better language, but as far as existing code is concerned it's as difficult
to port to some other language as it is from VB 6 to VB.NET).

I somehow doubt that all this is going to change the minds of the many shops
who *are* committed to Microsoft architectures. The fact that open source
products are more stable and better supported simply doesn't give them the
same warm fuzzy glow as being able to sign over huge chunks of their
corporate revenue stream for the dubious privilege of being able to call
Microsoft and have them say "fixed in next release".

Which, in the case of ODBC for example, turned out to be blatantly not true:
to miss some bugs in ODBC you have to migrate to OLEDB, which of course
turns out to be far less well supported cross-platform. This in turn is
because OLEDB was a set of marketing principles before it was ever a
technology.

So, having missed the emergence of the Internet as a crucial infrastructure
change, they are now trying to use their marketing muscle to surround it
with (in some cases) ill-thought-out proprietary technology. This will come
as no surprise to anybody who seriously read the Halloween documents, where
it was presaged as a strategy by suggestions that Microsoft make proprietary
extensions to open protocols as a way of retaining market share in the face
of the threat from Linux.

Would-be flamers please note: I am NOT saying that Microsoft have done
something they shouldn't from a business or a legal point of view: those are
different arguments. I'm simply saying that they have beaten even IBM at the
fear, uncertainty and doubt game. Were I a Microsoft stockholder I'd
probably be pleased. In the long term, though, I think that Microsoft
threaten their own survival by failing to embrace open systems rather than
seeing them as a threat to their markets. I doubt the DoJ anti-trust action
will be the last unless they change their ways, and nothing seems likey to
make them.

I sincerely doubt my, or anyone else's, ability to persuade Microsoft that
this is wisdom, and that they should listen to it!

regards
 Steve
--
http://www.holdenweb.com/

From ignacio at openservices.net  Mon Sep 10 17:44:36 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Mon, 10 Sep 2001 17:44:36 -0400 (EDT)
Subject: timing??
In-Reply-To: 
Message-ID: 

On Mon, 10 Sep 2001, NJM wrote:

> Would some one please give me an example of how to schedule an event for
> given times of a day; any day.
>
> For instance;  if I wanted to launch a wave file at 2:00 a.m.

Use crond, atd, or the Scheduler service, depending on what operating system
you're using.

-- 
Ignacio Vazquez-Abrams  

From doy20 at telcel.net.ve  Fri Sep 28 15:40:24 2001
From: doy20 at telcel.net.ve (Doy)
Date: Fri, 28 Sep 2001 15:40:24 -0400
Subject: Subscribe
Message-ID: <001301c14855$6c5340e0$0100a8c0@uhuihh>

------------------------------------
Make Unlimited phone calls from your PC to ANY phone in the World!
http://www.eboom.com/free/
-------------- next part --------------
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From aleax at aleax.it  Tue Sep  4 04:13:47 2001
From: aleax at aleax.it (Alex Martelli)
Date: Tue, 4 Sep 2001 10:13:47 +0200
Subject: 3-arg float pow()
References: 
Message-ID: <9n22fs01dt3@enews3.newsguy.com>

"Tim Peters"  wrote in message
news:mailman.999576723.20844.python-list at python.org...
> [Paul Rubi]
> > That doesn't seem so bad.  2**-5 is already not allowed.
>
> [Greg Ewing]
> > When new division comes into force, shouldn't this be allowed too?
>
> It's already allowed in current CVS Python.
>
> C:\Code\python\PCbuild>python
> Python 2.2a2+ (#22, Sep  3 2001, 14:31:58) [MSC 32 bit (Intel)] on win32
> Type "help", "copyright", "credits" or "license" for more information.
> >>> 2**-5
> 0.03125
> >>>

AND in plain 2.2alpha2, for those of us not quite adventurous
enough to track cvs:

C:\Python22>python
Python 2.2a2 (#22, Aug 22 2001, 01:24:03) [MSC 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> 2**-5
0.03125
>>>

Alex

From fredrik at pythonware.com  Tue Sep 18 17:09:07 2001
From: fredrik at pythonware.com (Fredrik Lundh)
Date: Tue, 18 Sep 2001 21:09:07 GMT
Subject: PIL 1.1.2 for Python 2.1.1
References: 
Message-ID: 

Anders Eriksson wrote:
> Why doesn't import Image work anymore?

what did you change?  what does "doesn't work" mean?

if you get an ImportError, check that you have the PIL
directory in your path.  if it's not there, make sure you
have a PIL.pth file in your python main directory (windows)
or under site-packages (unix).

> Why do I have to use import PIL.Image?

you don't, if you install it the right way.

From polopunk209 at hotmail.com  Mon Sep  3 23:13:29 2001
From: polopunk209 at hotmail.com (Josh)
Date: 3 Sep 2001 20:13:29 -0700
Subject: pygame rpg
Message-ID: 

i'm working on a top down rpg using pygame. does anyone have any ideas
on making graphics for games like this? it will not scroll in real
time. there will be a "level" on the screen, and when you walk off the
screen, a new "level" is blitted. also, do you have any ideas on where
i could look for some source code on a project similar to this? any
suggestions are appreciated, and thanks in advance.

josh

From qrczak at knm.org.pl  Mon Sep 17 13:35:53 2001
From: qrczak at knm.org.pl (Marcin 'Qrczak' Kowalczyk)
Date: 17 Sep 2001 17:35:53 GMT
Subject: newbie - Scoping question
References: <3281a460.0109170759.63ede66@posting.google.com>
Message-ID: 

17 Sep 2001 08:59:13 -0700, P Adhia  pisze:

> I am confused as to why "x", when not qualified with module name, does
> not refer to "x" in "test", even though I did "from test import *".

"from test import *" imports a module and injects a snapshot of the
module's namespace into the current namespace. Names in the current
namespace are then ordinary variables, bound to the same objects to
which the module has bound its variables at the time of the import,
but independent from the module. Further changes to the module's
namespace don't affect the current namespace, nor vice versa. It's
the same as if you did
    import test
    x = test.x
    get_x = test.x
    set_x = test.x
    del test
Now x and test.x are different variables referring to the same object.

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZAST?PCZA
QRCZAK

From zptang at hotmail.com  Fri Sep 21 21:55:24 2001
From: zptang at hotmail.com (Janet)
Date: 21 Sep 2001 18:55:24 -0700
Subject: Problem using new Python type: "cannot add type to string"
Message-ID: 

Hi,

I created a new Python type (extension in C), and tried to call a
function with an object of the new type as the argument:

PyObject *arglist = PyTuple_New(1);
PyTuple_SetItem(arglist, 0, myObj); /* myObj is an object of the new
type */
PyObject_CallObject(funcObj, arglist);...

However,  the PyObject_CallObject() failed with the error message
saying that: "cannot add type  to string".  It seems
that the error was generated when string_concat() in
Objects/stringobject.c is invoked.  The function tested on the type of
the second argument and outputted error whenever the argument is not a
PyStringObject.
I would like to know why does this problem appear.  Is there any
methods in the new type that I forgot to implement? (BTW, I did
implemented the tp_str, tp_repr, and tp_print in my new type).

Thanks

From donn at u.washington.edu  Tue Sep  4 12:47:52 2001
From: donn at u.washington.edu (Donn Cave)
Date: 4 Sep 2001 16:47:52 GMT
Subject: Conditional operator in Python?
References: <3AC68CB8.22AAF7B8@alcyone.com> <9a631k$3s8qb$1@ID-11957.news.dfncis.de>  <3AC6BB2E.1E09B5AA@alcyone.com>  <9n1hr7$7op$1@glue.ucr.edu> <3B947E32.C5604328@el_simpatico.be>  <3B94B3B3.6775EE3C@el_simpatico.be>
Message-ID: <9n30jo$18ls$1@nntp6.u.washington.edu>

Quoth Weet Vanniks :
| Your counter-example seems contorted to me.
| I would never use:
|     whatever = cond_choose(cond, format_disk(), leave_it_as_is())
| for the mere reason that I have been taught that:
|     1. when there is room for confusion, people get confused
|     2. arguments in a function call should NEVER have side-effects.
|     3. obfuscated one-liners with lambda functions bring more confusion
| than anything else
|         (the alledged efficiency is still to be demonstrated as you
| correctly state)
|     4. The spirit of Python is : "If it ain't obvious, it ain't Python"
| and contorted syntax does not help support that spirit

/F is notorious for his elliptical replies, but not for contorted
syntax, and I think the former is the problem here.  The way I read
it, the usage he was promoting was the most obvious possible,
"if cond ..."

I might add, one of the reasons it's so much more obvious than the
pseudolisp alternatives is that the "if" is clearly directed at the
"cond" variable, whereas in the post that someone forged your name
to that suggested "whatever= cond_choose(x,a,b)", it's not so clear
where the condition is.

	Donn Cave, donn at u.washington.edu

----------------------------------------
| Fredrik Lundh wrote:
|
|> Weet Vanniks wrote:
|> > What about :
|> >
|> > def cond_choose(cond,first_choice,second_choice):
|> >      if cond:
|> >           return first_choice
|> >      return second_choice
|> >
|> > whatever= cond_choose(x,a,b)
|>
|> well, compare
|>
|> whatever = cond_choose(cond, format_disk(), leave_it_as_is())
|>
|> with
|>
|>     if cond:
|>         whatever = format_disk()
|>     else:
|>         whatever = leave_it_as_is()
|>
|> > This seems much cleaner to me than all those contorsions with
|> > the syntax.
|>
|> of course, the best way to avoid those contorsions is to fix the
|> Return and Tab keys on your keyboard, and learn how and when
|> to use them...
|>
|> (it also helps to know that lambdas and list constructors are
|> expensive, and assignments to temporary locals are cheap.
|> And contrary to common belief, the Python interpreter can
|> skip over linefeeds in almost no time at all...)
|>
|> 

From wolfgang.grafen at marconi.com  Wed Sep 26 14:32:16 2001
From: wolfgang.grafen at marconi.com (Wolfgang Grafen)
Date: Wed, 26 Sep 2001 20:32:16 +0200
Subject: Idea about method parameters
References: <2728946.ogB4TqSGss@lunix.schabi.de> <3BAF6D67.ADA04E71@marconi.com> <5594719.3gRfpFWEtP@lunix.schabi.de>
Message-ID: <3BB21F30.4FE0F893@marconi.com>

Well, Python is flexible to do it anyway and although I missed 
to give an example for that I hoped you could develop by yourself:

>>> class A:
...     def __init__(self,a,b,c=333,d=444):
...         self.__dict__.update(vars())
...         del self.__dict__['self'] # remove cyclic self reference
...     def __call__(self):
...         print self.a, self.b, self.c, self.d

>>> a=A(a=1,b=2,c=3) # qualified and default parameters
>>> a() 
1 2 3 444
>>> 

>>> a=A(1,2,3,4) # positional parameters
>>> a()
1 2 3 4

>>> a=A(1,2) #positional and default parameters
>>> a
>>> a()
1 2 333 444

>>> a=A(1,c=3,b=22) # positional, qualified and default parameters
>>> a()
1 22 3 444

Answers to your objections (below):
1. Now the parameter list is under the programmer's control
2. Using self.__dict__ is *not* a dirty hack as already many code 
   does use self.__dict__ 
3. Positional parameters are possible as well
4. There are default values 
5. No need for an extra documentation of valid parameters

For me this is good enough and there is no need for a new syntax.

Wolfgang

Markus Schaber wrote:
> 
> Wolfgang Grafen  schrub:
> 
> > Don't think you cannot do it already!
> >
> >>>> class Autoinit:
> > ...     def __init__(self,**a):
> > ...         self.__dict__.update(a)
> > ...
> >>>> a=Autoinit(a=1,b=2,c=3)
> >>>> a.a
> > 1
> >>>> a.b
> > 2
> >>>> a.c
> > 3
> >
> >>>> class A(Autoinit):
> > ...   def __call__(self):
> > ...     print self.a,self.b,self.c
> > ...
> >>>> a=A(a=1,b=2,c=3)
> >>>> a()
> > 1 2 3
> 
> Nice idea, especially when your classes mainly work as Attribute
> Containers, but I have some objections:
> 
> 1. This way you don't have any control what the caller sets - he just
> might set anything. Okay, in Python, he really can do anything he wants
> with your object, but sometimes it is helpful to have some hints by the
> compiler or interpreter, especially to find typos (useful when you have
> lots of long-named parameters). And if you have to test the contents of
> **a "by hand", you don't save any work, and it gets less readable.
> 
> Assume you have more than one place in your program where that
> constructor/method gets called, one of them has a typo in one parameter
> name, and so you occasionally corrupt parts of your database. Or the
> misspelled parameter sets an attribute that is never looked at again,
> and all the following code uses the old value from the correctly
> spelled attribute that was created before (only applies to
> non-constructor methods)
> 
> 2. Messing with __dict__ seems to be a "dirty hack" in my eyes, and
> doesn't produce readable code (you cannot exactly guess what gets
> changed in the object, especially when it isn't the constructor, but
> another method.)
> 
> 3. You kick the possibility to give positional parameters
> 
> 4. You kick the possibility to give default value
> 
> 5. You have to explicitly document what your caller can give you - a
> "normal" parameter list in a def: with sensible parameter names (and
> maybe useful default values) usually is a very useful bit of
> documentation, especially when you know the main idea and just forgot
> some specific spelling detail or so.
> 
> markus
> --
> "The strength of the Constitution lies entirely in the determination of
> each citizen to defend it. Only if every single citizen feels duty
> bound to do his share in this defense are the constitutional rights
> secure." -- Albert Einstein

From tim.one at home.com  Thu Sep  6 01:42:27 2001
From: tim.one at home.com (Tim Peters)
Date: Thu, 6 Sep 2001 01:42:27 -0400
Subject: 3-arg float pow()
In-Reply-To: 
Message-ID: 

[Tim]
> I'm sure David knows all that.

[Fredrik Lundh]
> yeah, but what about everyone else on this list?  am I the
> only one here that didn't know this (okay, okay, I could've
> looked it up somewhere if I really needed the info ;-)

Far be it from me to complain about off-topic posts -- and the writeup was a
good one.

My purpose was to spare David the need to explain himself, and especially to
spare "everyone else on this list" the explanation .

six-words-were-really-all-that-needed-ly y'rs  - tim

From jknapka at earthlink.net  Sun Sep  2 20:46:44 2001
From: jknapka at earthlink.net (Joseph Andrew Knapka)
Date: Mon, 03 Sep 2001 00:46:44 GMT
Subject: Tkinter design problem
References: <3b92af17_8@news.newsgroups.com> <3b92c2cf$0$326$6e49188b@news.goldengate.net>
Message-ID: <3B927DEE.2347A972@earthlink.net>

Greg Krohn wrote:
> 
> If you bind your callback it sends back an event argument that has
> the 'widget' attribute. That is the widget that called it.

And if you want to just use the "command" option, pass it
a curried function. There have been several recent threads
on this matter; see for example

Oh well, that URL got chopped to bits, but googlegrouping for
"curry Tkinter" will get you there.

Cheers,

-- 
# Joe Knapka
# "You know how many remote castles there are along the
#  gorges? You can't MOVE for remote castles!" - Lu Tze re. Uberwald
# Linux MM docs:
http://home.earthlink.net/~jknapka/linux-mm/vmoutline.html

From mmhamze at pleiades.net  Tue Sep  4 09:46:53 2001
From: mmhamze at pleiades.net (Maan M. Hamze)
Date: Tue, 4 Sep 2001 08:46:53 -0500
Subject: how do i make a grapical thingie?
References:   
Message-ID: 

Hi Jeroen
Ok!
1.  Do you have the directory:  c:\python22\Lib\lib-tk?
2.  type the following in Python:
>>> import sys
>>> sys.path
You'll get a string.  What string are you getting?
Maan

"jeroen paul goudsmit"  wrote in message
news:LV1l7.24$3M6.646 at castor.casema.net...
> Ok. Python is instal;led in : C:\Python22.  The name of the executable is
=
> C:\Python22\python.exe. The dll files are in the map C:\Python22\DLLs. The
> tkinter file is C:\Python22\DLLs\_tkinter.pyd.
> "Maan Hamze"  schreef in bericht
> news:HQOk7.217122$g_3.41849242 at typhoon.austin.rr.com...
> > Tim
> > The guy had not even answered on how he has Python installed to start
> with.
> > To recommend Jython for him at this stage along with the use of AWT or
> swing
> > is an overkill :)
> > Maan
> >
> > "Delaney, Timothy"  wrote in message
> > news:mailman.999478982.9172.python-list at python.org...
> > > I suspect the simplest thing here would be to use Jython and AWT or
> Swing.
> > >
> > > http://www.jython.org
> > >
> > > Probably the easiest way for a beginner to get a GUI up and running in
> > > Python. Once they have a bit more experience they can move onto other
> > > things.
> > >
> > > Tim Delaney
> > >
> >
> >
>
>
>
>

From BrianQ at ActiveState.com  Thu Sep 13 20:56:43 2001
From: BrianQ at ActiveState.com (Brian Quinlan)
Date: Thu, 13 Sep 2001 17:56:43 -0700
Subject: Python on OSX
In-Reply-To: <4a249347.0109131633.5eb04510@posting.google.com>
Message-ID: <002101c13cb8$1f6e83f0$b503a8c0@activestate.ca>

 > Are there any "gotchas" when compiling Python on OSX? Is
> there a how-to someplace?

Read the README file that comes with the Python source/cvs. There are
a few switches that you have to pass explicitly to autoconf but other
than that everything works fine.

From BPettersen at NAREX.com  Wed Sep 12 19:32:13 2001
From: BPettersen at NAREX.com (Bjorn Pettersen)
Date: Wed, 12 Sep 2001 17:32:13 -0600
Subject: Reading variable length records...
Message-ID: <6957F6A694B49A4096F7CFD0D900042F6C9E32@admin56.narex.com>

> From: Brian Quinlan [mailto:BrianQ at ActiveState.com]
> 
> > I'm trying to read records from a 2 GB datafile, but my brain has
> > stopped working, so I was wondering if someone has allready 
> > solved this problem. The records are variable length and are 
> > separated by a five character delimiter. I was trying to use 
> > file.read(n) with a blocksize of ~1Mb, but got a serious 
> > brainfart when trying to think of how to handle the case where 
> > only part of the delimiter was read in the current block.
> 
> Here is some pseudo-code to get you started:
> 

Thanks, that helps alot :-)

-- bjorn

From James_Althoff at i2.com  Tue Sep  4 13:13:03 2001
From: James_Althoff at i2.com (James_Althoff at i2.com)
Date: Tue, 4 Sep 2001 10:13:03 -0700
Subject: how to distinguish a python expression from a statement?
Message-ID: 

Thanks for your suggestion, Fredrik.

I must be doing something wrong, though, because I don't seem to be getting
the expected behaviour.  The magic "_" variable works when I type directly
into the Python interpreter (interactive mode).  But when I run your
example code using either Python or Jython, "_" is not defined (as part of
the exec statement).

Python 2.2a1 (#21, Jul 18 2001, 04:25:46) [MSC 32 bit (Intel)] on win32
Type "copyright", "credits" or "license" for more information.
>>> mysource = '3+4'
>>> dict = {}
>>> code = compile(mysource,"","single")
>>> exec code in dict
7
>>> result = dict.get("_")
>>> if result is not None:
...   print result
...
>>> print result
None
>>>
>>>
>>> 3+5
8
>>> _
8
>>>

Do I need to do something special to enable the magic "_" to be included in
an exec statement?

Thanks,

Jim

Fredrik Lundh wrote:
>sure:
>James_Althoff at i2.com wrote:
>> I have all of this working except that I don't know how to distinguish
>> between expressions and statements (without making the end user push one
of
>> two different buttons in order to tell me -- yuk).  I am using Jython
and
>> so the parser module is not available (so I can't use parser.isexpr).
>>
>> Is there any means to accomplish this
what-I-had-thought-would-be-routine
>> task short of writing a Python parser?
>
>
>    dict = {}
>    code = compile(mysource, "", "single")
>    exec code in dict
>    result = dict.get("_")
>    if result is not None:
>        print result
>
>(use dict.has_key("_") to check if it really was an expression)
>
>> I am trying to mimick the Python interpreter in a GUI.
>
>the "code" module contains a framework for this; just instantiate
>an InteractiveConsole, and use the "push" method to add lines as
>they arrive from the GUI.
>
>

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

From aleax at aleax.it  Tue Sep  4 11:00:09 2001
From: aleax at aleax.it (Alex Martelli)
Date: Tue, 4 Sep 2001 17:00:09 +0200
Subject: Use of GMPY
References: <9n03in$c6o$1@pegasus.tiscalinet.it>  
Message-ID: <9n2qa00dj3@enews3.newsguy.com>

"Maan Hamze"  wrote in message
news:ilPk7.217241$g_3.41893539 at typhoon.austin.rr.com...
> I have never used GMPY, but it is not always the case that *.pyd files
> should go into the DLL subdirectory.  It may be the way that GMPY is being
> imported where the problem lies.
> Does GMPY have a setup script?  Maybe you are copying the PYD's into
places
> where GMPY can not find them.

A setup.py is part of the *source* distribution of GMPY.  The
windows-binaries package, provided as a convenience to Windows
users, is made up of just two .PYD's which, if one wishes, may
well be "installed" by copying them anywhere Python will find
them.  HOWEVER, the 0.9 version is built for Python 2.0; in
response to the original post, I've released a 0.9a21 that is
basically identical BUT built for Python 2.1.

Note that one needs the source distribution anyway, because
that's where the docs are (just a large textfile, at present),
as well as the unit-tests &c.  Yep, I _do_ need to come up
with slicker packaging at some point (presumably when I redo
the docs in a slicker format than plain text:-).

Alex

From wayne at tbnets.com  Sun Sep  9 19:58:19 2001
From: wayne at tbnets.com (Wayne Ringling)
Date: Sun, 9 Sep 2001 19:58:19 -0400
Subject: Interesting problem with running a python script in a c wrapper.
Message-ID: 

 I have been progressing on my project and ran into this little problem.  I
have a script that is wrapped with the c wrapper from the python /Misc dir
and when I run it from my web server I  get the error below:  I show my
script first and then the error.

login.py--------------------------------------------------------------

 #!/usr/bin/python

import config, keys, misc, shelve, anydbm

config = config.Confload()
encrypt_key = keys.generate_shortkey()
remote_ip = misc.grab_remoteip()

session_key_dbm = shelve.open(config.files.session_key_dbm, 'c')
session_key_dbm.close()

session_key_dbm = shelve.open(config.files.session_key_dbm)
session_key_dbm[encrypt_key] = remote_ip

print "Content-type: html/text\n\n"
print "Test Page"
print ""
for key in session_key_dbm.keys():
	print key, " -> ", session_key_dbm[key],"\n
"

print ""

session_key_dbm.close()
login.py--------------------------------------------------------------------

/var/log/httpd/error_log----------------------------------------------------
Traceback (most recent call last):
  File "/freesite-cgi/login.py", line 13, in ?
    session_key_dbm = shelve.open(config.files.session_key_dbm)
  File "/usr/lib/python2.0/shelve.py", line 157, in open
    return DbfilenameShelf(filename, flag)
  File "/usr/lib/python2.0/shelve.py", line 147, in __init__
    Shelf.__init__(self, anydbm.open(filename, flag))
  File "/usr/lib/python2.0/anydbm.py", line 86, in open
    return mod.open(file, flag, mode)
  File "/usr/lib/python2.0/dbhash.py", line 8, in open
    return bsddb.hashopen(file, flag, mode)
bsddb.error: (21, 'Is a directory')
[Sun Sep  9 21:42:35 2001] [error] [client 216.181.182.140] Premature end of
script headers: /usr/local/httpd/cgi-bin/login
/var/log/httpd/error_log----------------------------------------------------

Now I know that "config.files.session_key_dbm" does =
"/usr/local/freesite/sessionkey_dbm"

It creates the dbm in the correct dir and then when it goes to read it.  I
get the above error in my http server log. And the server sends a 500 error
to the web browser.

My server is a Suse 7.2 running Apache and mod_python.  Not sure if this
info helps but you never know.

Btw the script works fine from the command line. Any Ideas?

Wayne

From rdsteph at earthlink.net  Mon Sep 10 21:12:30 2001
From: rdsteph at earthlink.net (Ron Stephens)
Date: Tue, 11 Sep 2001 01:12:30 GMT
Subject: Pythonwin and .NET
References:  <3B997A5E.6010801@bigpond.net.au>
Message-ID: <3B9D6654.FA287BA5@earthlink.net>

I have a question that I hope someone can partially answer. ActiveState has a beta
of Visual Python for .Net on their web site. I can not use it because I do not
have access to a beta of Microsoft's Visual Studio. However, the ActiveState beta
of Visual Python must have at least basic functionality.

How basic is that functionality? How much is left out? Are there big differences
between the language supported as Visual Python and c-Python as we know it?

Mr. Mark Hammond said

"""And on the more pragmatic side, there is still *significant* work
remaining to be done before Python on .NET is really viable, and I know
of no commercial effort underway to implement this.  From memory,
JPython took a number of years to be considered viable and to transform
into Jython."""

Mr. Hammond, why is Python on .NET not currently viable? Also, do you think
ActiveState will stick with it until it is viable?

Look, I like many on this list would love to see you, Mr. Hammond, champion Python
on .NET to the n'th degree. I would say just about anything to try to persuade you
to do so ;-)) But, I know you are a very busy person and will certainly make up
your own mind on important matters. And I think it must be discouraging sometimes
to work so hard for so long and not see all the progress you would like to see.
This is a burden you must bear alone and most of us can't participate with you at
all nor understand it at all.

But we can continue to say thank you, regardless of any and all decisions and
outcomes.

Now, I hope Alex Martelli decides to volunteer to help Mark Hammond do a PythoNet.
I hope Alex volunteers to lead an open source effort himself, should Mr. Hammond
decide to not do so. I am sure it would help the Python community immensely of
they did so. But even if they don't, Python has a great future.

Why?

1. Microsoft rules. VB and C# will therefore rule. Most of all, Visual Studio .NET
will truly rule. Java will not go away and will be very important. Perl and even
JavaScript and other scripting and glue languages have roles for quite a while.
Other great but boutique languages will make some very happy, like Oberon,
Haskell, Eiffel, etc. etc. etc. Lisp will have its own very efficient and
productive advocates until they all die. ;-)))

But other than the greater C family of C, C++, C#, and Java, only Python exists
today as a claimant to more than a token stance as an important general purpose
language that is still growing, at least significantly. Perl could be considered,
but is it really a general purpose language? Ruby has aspirations, and is probably
a fine language, and could be as general purpose as Python, maybe, in time, but it
doesn't have the time, nor does it have enough critical mass. The window is
closing. Only a language that has at least as much presence, tool availability and
maturity as Python has time, to my way of thinking , to survive the onslaught of
.NET and Java both and have the opportunity to evolve and grow into a *major*
general purpose language.

So, on one side you have Visual Studio, C# and VB (and also managed code C++),
pushed by the most powerful corporation the earth has ever seen; and on the other
side you have Java, with at least a five year head start and supported by IBM, Sun
and other major corporations.

In the middle, you have one open source language named after a troupe of
comedians, saddled with a snake's name that has sensitive and negative
connotations to some ;-)), and a BDFL who believes in it and in its community.

2. Python occupies a middle ground. Neither fish nor foul, neither Sun nor
Microsoft, but friendly to both companies and to open source advocates, used by
Windows developers (thanks to Mark Hammond!!!) and by Linux developers and by Mac
and BSD and other UNIX developers, Python is no one's enemy and everyone's friend.
To both the Microsoft camp and to the Java camp, one who is not my enemy is maybe
my friend, and at least can be tolerated and allowed to live.

3. Python is as widely usable as any language, if not wider. If successfully
integrated into .NET in the early days, even if not with 100% perfection, Python
will be *the* most widely cross platform, cross development environment,
programming language on earth. Java will not be so early and well integrated into
.NET, and even if it is, the Java community will not support Java.NET
enthusiastically, for obvious reasons. Python will move ahead of even Java in
open, cross platform support. And when will VB and C# be running on JVM's?

4. The Python community nurtures what is arguably one of the five most important
concentrations  of software development going on today:

        A. Microsoft .NET
        B. Java
        C. Linux
        D. Mono (and what about PythoNet for Mono?)
        E. Python
            i. The core Python language led by Guido
            ii. Jython
            iii. Python.Net
            iiii. Web App Servers like Zope, Webware, Skunkworks etc. etc. etc.
            iiii. Commercial IDE's PythonWare, Black Adder, and Komodo
            iiii. Open source Python GUI RAD tools and application frameworks
like:
                    a. wxPython and similar for GTK, QT, Tkinter, etc.
                    b. Boa Constructor
                    c. anygui
                    d. PythonCard

5. By continuing to grow as a friendly flower in the midst of the two giants (Java
and Microsoft), Python garners good will; and offers a neutral alternative for the
future.

But most of all, there is another reason, more important than any of the above and
all of the above reasons combined.

When we  ask ourselves, honestly, what will still be around in the year 2010, or
even in 2020, what comes to mind, and how do we predict such things? Well,
Microsoft and its preferred offerings, whatever they are, will certainly not only
be around but will be hugely important, for the foreseeable future, due to their
corporate might and will. Java will still be around, because it has so much
momentum. The C family in general will be around; C is too important to ever be
completely replaced in the foreseeable future. But surely there is a place for a
more productive, higher level language?

OS/2 was loved by many and will not be around in 2020 or even in 2010 to any
appreciable degree. So love of a technology alone is not enough to ensure
survival.

But I am quite sure that Python will be around, and important, in 2010; and I
believe it will also be so in 2020. Why? Because so many people truly love it, in
a meaningful way (they love to use it, they use it deeply, it is a tool that helps
them be significantly more productive and yes, fulfilled in their careers and in
their passions); and because so many people will continue to love it and use it in
2010, and enough people to make a difference; and because Python is an open source
community that can not be killed in the way IBM and Microsoft killed OS/2.

Python will survive because it is open source and loved. Python will matter
because loved tools that are free, if they are loved and used by enough people,
grow and thrive.

Think about it; do you believe that Python is loved enough, by enough people, in
a  useful and not just sentimental way, so that it will be used by a significant
enough number of people in 2010 to be meaningful? And if still sufficiently used
and meaningful in 2010, would not Python be situated to possibly become important,
in the middle ground of computer languages?

I actually believe this; I hope you do too.

I humbly salute and honor Guido and Mark and Alex and all of the other heroes of
the Python community. I hope some of these heroes propel Python .Net forward.

But under any circumstances, I have a sober faith that Python will do well, and I
will continue to use Python and cherish its community lovingly..

Ron Stephens

From Tobias_Unruh at FRM2.TU-Muenchen.DE  Wed Sep  5 08:00:18 2001
From: Tobias_Unruh at FRM2.TU-Muenchen.DE (Tobias Unruh)
Date: Wed, 5 Sep 2001 14:00:18 +0200 (CEST)
Subject: (no subject)
Message-ID: 

Hi,

I am looking for something like a trap/resume functionallity for python.
Does anyone know if there exists a solution? Or is it possible to
install a timer, which interrupts the current program and calls a
subroutine, say 5 times per second.

Tobias

--
Tobias Unruh
TU Muenchen, FRM-II
85747 Garching, Germany

From jan_mothers at hotmail.com  Sun Sep 16 18:30:15 2001
From: jan_mothers at hotmail.com (jan_mothers at hotmail.com)
Date: 16 Sep 2001 22:30:15 GMT
Subject: A PERFECT TAN WITHOUT THE SUN Or Your Money Back
Message-ID: <9o395n$6c6$1223@plutonium.btinternet.com>

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From loewis at informatik.hu-berlin.de  Fri Sep 28 03:50:29 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 28 Sep 2001 09:50:29 +0200
Subject: Secure embedding of Python
References: <605d9ec1.0109270117.4bb31eb4@posting.google.com>
Message-ID: 

tordj at scalado.com (Tord Jansson) writes:

> 2. Lock out the use of any other modules. If not possible in any other
> way I can always scan through the script before execution for any
> inclusion of other modules.

It is easily possible. The only danger comes from C modules; Python
modules cause no security risk, since they eventually have to perform
all their actions through C modules.

By restricting the list of C modules (and builtins), you effectively
and reliably limit what Python code can do. If you look for several
levels of access, you need the rexec module, which allows to further
limit the set of available functions.

To limit the list of available C modules, you best link every module
that you want to offer into your application, and remove the
possibility for dynamically loading extension modules. To do that,
make sure that HAVE_DYNAMIC_LOADING is not defined.

> 1. Will this approach effectively lock out access to file-functions
> etc or are some dangerous functionality built into the interpreter
> itself?

Yes, you need to disable the open function. That may require changes
to builtinsmodule.

> 2. Is some necessary functionality (memory allocation for
> example)placed in modules which I therefore will have to include?

Yes. You cannot disable the sysmodule and the builtins module. If you
need gc, you must include the gcmodule, and if you need threads, you
must include the threadmodule. It is also advisable to include the
strings module and the _sre module.

> 3. Is there any way to access (read and/or write) raw memory in
> Python which might be hard to lock out? Something similar to just
> giving a pointer a value and reading from there in C/C++? Writing
> outside its own array structures?

That is not possible. With the mmap module, you can write to raw
memory, but not with random access to the address space.

Regards,
Martin

From jtdubs at eos.ncsu.edu  Tue Sep 11 19:07:13 2001
From: jtdubs at eos.ncsu.edu (Justin Dubs)
Date: Tue, 11 Sep 2001 19:07:13 -0400
Subject: multi-dispatch (was Re: large class hierarchies in python)
References:  <9ner16$sbt$1@uni00nw.unity.ncsu.edu> <7934d084.0109091703.6414e22a@posting.google.com> <9nhhn5$g1o$1@uni00nw.unity.ncsu.edu> <9nhugd0s4f@enews1.newsguy.com> <9ni3p0$rkn$1@uni00nw.unity.ncsu.edu> <9nieii01k24@enews1.newsguy.com> <9nismr$fve$1@uni00nw.unity.ncsu.edu> <9nksof021p1@enews3.newsguy.com>
Message-ID: <9nm5ev$pfr$1@uni00nw.unity.ncsu.edu>

"Alex Martelli"  wrote in message
news:9nksof021p1 at enews3.newsguy.com...
> "Justin Dubs"  wrote in message
> news:9nismr$fve$1 at uni00nw.unity.ncsu.edu...
 ...
> A brief tirade in favour of multi-dispatching...:
>
> It's runtime-polymorphism over an unlimited number of objects, rather
> than over one object at a time.  In any language that doesn't offer
...
> And the Dylan implementation looks fine to me in as far
> as I've dug into it.  What do you find wrong with it...?

Ahhhhhh..... Thank you.  I didn't spend enough time letting the concepts
sink in.  Thanks for the great explanation.  It makes sense now.  That is
very useful.  I still hate the dylan syntax, but the multi-dispatching makes
sense now.  Thank you for the help.

Justin Dubs

From skip at pobox.com  Fri Sep 21 09:37:36 2001
From: skip at pobox.com (Skip Montanaro)
Date: Fri, 21 Sep 2001 08:37:36 -0500
Subject: How to derive import dependency structure
In-Reply-To: 
References: 
Message-ID: <15275.17056.897781.994423@beluga.mojam.com>

    Harald> Let B.py be imported by A.py which generates --- in a very time
    Harald> consuming process --- some data structure A.dat.

    Harald>          import         generate
    Harald>    B.py --------> A.py ----------> A.data

    Harald> Currently A.dat is only generated if A.py is newer, but this is
    Harald> not enough since A.dat must also be generated, if B.py is
    Harald> changed.

Sounds like make dependencies to me:

    A.data : B.py A.py
        python B.py             # writes A.data by side effect 

If make isn't an option, perhaps distutils will do the trick.

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/

From weeks at vitus.scs.agilent.com  Sun Sep  9 21:23:35 2001
From: weeks at vitus.scs.agilent.com (Greg Weeks)
Date: Mon, 10 Sep 2001 01:23:35 +0000 (UTC)
Subject: language growth
Message-ID: <1000085015.952637@cswreg.cos.agilent.com>

I just happened to notice a PEP stating that a certain additional construct
would be "a good idea".  I imagine that there are lots of good ideas out
there, genuine and perhaps even significant language improvements.  But I'm
move convinced of this: If every significant language improvement were
added to the language, it wouldn't be an improvement at all.  All those
good things would add up to a bad thing.  The optimal size for a language
is not enormous.

So, it seems to me that at some point it is desirable to reject good ideas.
The bar needs to be raised to allow only great ideas, and then at some
later point to allow only insanely great ideas.  At that point the language
will change glacially, if at all.

If that is correct, how do you raise the bar?  How do you decide that an
idea that would have been desirable five years ago is no longer good enough
for inclusion?  How do you decide how big/complex a language should be?

I don't know, but this seems relevant to Python.  (And I need to get a
small number of potentially puerile and undergraduate postings out of my
system.)

Regards,
Greg

From max at alcyone.com  Thu Sep 13 01:53:54 2001
From: max at alcyone.com (Erik Max Francis)
Date: Wed, 12 Sep 2001 22:53:54 -0700
Subject: Proposed PEP for a Conditional Expression
References:  <6qvgire4bk.fsf@abnoba.intevation.de> <9nk3jd$4lc$1@glue.ucr.edu> <9nnsa3$bjl$1@news.mathworks.com>  <3BA00239.DECE6412@cosc.canterbury.ac.nz>  <5xXn7.2447$w62.1612177@news1.denver1.co.home.com> <9nphfq$ph3$2@glue.ucr.edu>
Message-ID: <3BA049F2.B3895DDE@alcyone.com>

thp at cs.ucr.edu wrote:

> C syntax does overload the already heavily used colon.

The colon isn't used all that much in C.  It's used in labels and
switch...case statements, the conditional operator, and bitfields.

> Perhaps it
> would be better to use semicolon instead of colon.

The colon is too overloaded in C, but the semicolon isn't?  At least one
semicolon appears in every C statement.

-- 
 Erik Max Francis / max at alcyone.com / http://www.alcyone.com/max/
 __ San Jose, CA, US / 37 20 N 121 53 W / ICQ16063900 / &tSftDotIotE
/  \ There are countless planets, like many island Earths ...
\__/ Konstantin Tsiolkovsky
    REALpolitik / http://www.realpolitik.com/
 Get your own customized newsfeed online in realtime ... for free!

From ullrich at math.okstate.edu  Mon Sep  3 10:31:04 2001
From: ullrich at math.okstate.edu (David C. Ullrich)
Date: Mon, 03 Sep 2001 14:31:04 GMT
Subject: typechecks: just say no! (was Re: Determining Types)
References:  <9mvo0u04o8@enews2.newsguy.com>
Message-ID: <3b938f31.2123170@nntp.sprynet.com>

On Mon, 3 Sep 2001 13:02:54 +0200, "Alex Martelli" 
wrote:

>"Adonis Vargas"  wrote in message
>news:fe9k7.1835$ix.446807 at newsrump.sjc.telocity.net...
>> how am i able to determine types of variables? i have come up with the
>
>Be aware that, MOST times you THINK you need to typecheck, you
>really *don't*.  Type-checks break the wonderful signature based
>polymorphism that is the key to so much of Python's power and
>simplicity.  Check out the Cookbook recipe:
>http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52291
>for a way to avoid type-checking (in favour of signature
>checking) even when you might think it's indispensable.

Just the other day I did something that involves type checking.
I felt guilty about it, but it gives me what I want. How do
I do the following without type-checking? (Or how do I do
something other than the following that retains the keenness
of it?)

I have records. Rec has (almost) no user-defined attributes except
for __getitem__; fields are assigned dynamically from
field names in the database, using settattr() when a record
is read. So I can use rec.thisfield and rec.thatfield even
though the Rec class doesn't know about "thisfield" and
"thatfield", keen.

But in other places it's good to be able to refer to
fields with non-literal names, so I add a __getitem__
so that rec['thisfield'] returns rec.thisfield. 
(Actually the main reason I want this is so that I
can use a Rec as a mapping in a string format thing:

'Your name is %(Name)s' % rec)

In yet other places I want to iterate over the fields 
of a record, as in

for key, value in rec:

So in __getitem__ I check the type of index, returning
getattr(self, index) if index is a string and saying

fieldname=self.__fieldnames__[index]
return (fieldname, getattr(self, fieldname))

if index is an integer.

Seems utterly keen to be able to use them as both 
lists and as mappings, as needed.

David C. Ullrich

From tolot at solar-system.dynodns.net  Thu Sep 13 16:10:39 2001
From: tolot at solar-system.dynodns.net (Marc Christiansen)
Date: Thu, 13 Sep 2001 22:10:39 +0200
Subject: unicode strings and such
References:  <3BA0CC8E.1050705@hp.com>
Message-ID: 

Garth Grimm  wrote:

One thing apparently nobody noticed until now, this line
>      patternRegex = re.compile(pattern,re.UNICODE or re.IGNORECASE)

should probably read
     patternRegex = re.compile(pattern,re.UNICODE | re.IGNORECASE)
(or use '+' instead of '|', in this case it doesn't matter).
'or' is the logical or, not the binary (or however it is called).
To see the difference, do a

print re.UNICODE, re.IGNORECASE
print re.UNICODE or re.IGNORECASE, re.UNICODE | re.IGNORECASE

from the python prompt.

HTH
  Marc

From aleax at aleax.it  Mon Sep  3 05:39:07 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 3 Sep 2001 11:39:07 +0200
Subject: Unicode -> UTF-8
References: 
Message-ID: <9mvj3t03044@enews2.newsguy.com>

"Ignacio Vazquez-Abrams"  wrote in message
news:mailman.999477366.3290.python-list at python.org...
> What's the easiest way in C to get the contents of a PyUnicodeObject (or a
> PyStringObject for that matter) as UTF-8?

What about (warning, untested code):

void
treat_as_utf8(PyObject* pSomeUnicode)
{
    char* buffer;
    int length;
    int rc;

    PyObject* pAstring =
PyObject_CallMethod(pSomeUnicode,"encode","s","utf8");
    if(!pAstring) return;

    rc = PyString_AsStringAndSize(pAstring, &buffer, &length);

    if(rc==0) {
        /* snipped: use buffer (READ-ONLY!) & length as you wish */
    }

    Py_DECREF(pAstring);
}

Is this what you had in mind?

There are also "es" and "es#" formats which I think you should
be able to use directly with PyArg_Parse, a la (I think):

    buffer = 0;
    rc = PyArg_Parse(pSomeUnicode, "es#", "utf8", &buffer, &length);

    /* check rc & use buffer/length, read/write now */

    PyMem_Free(buffer);

but I'm unclear on the status/usability of PyArg_Parse -- the
current docs say it's all right to use it to analyze other
object (not arguments), but I've seen people "in the know"
just flat out advise against using it and claiming it is in
fact deprecated (without qualifying that warning with "for
argument parsing only").  Maybe this thread can lead to some
useful clarification in this regard...?

Alex

From aleaxit at yahoo.com  Sun Sep  9 14:00:05 2001
From: aleaxit at yahoo.com (Alex Martelli)
Date: Sun, 9 Sep 2001 20:00:05 +0200
Subject: Proposed PEP for a Conditional Expression
References: 
Message-ID: <9nganb0t8f@enews1.newsguy.com>

Michael Chermside wrote:

[excellent work snipped, as I just want to snipe on one point...]

>              using it may require creating a temporary variable and
>              splitting a formula into two lines, or replacing a lambda
>              expression with a named function.

I consider that replacing lambda forms with named functions, in Python, is 
an *excellent* practice, which should be encouraged by all means necessary. 
 If the lack of a conditional operator does indeed encourage people to 
write more local def's and fewer lambdas, then (to me) that is the "killer 
argument" for not introducing conditional operators.

Maybe (it's been hotly and often debated, but never PEP'd) Python would 
benefit from having some more general way to insert an unnamed code block 
on the fly.  But Python's lambda, as it stands, is so limited and unwieldy 
that encouraging more use of it makes no sense to me.  If we get more 
powerful lambda-like/unnamed-block-like constructs, then the issue may go 
away (I don't think such an introduction would greatly benefit Python, as 
it only introduces more ways to do the same things, and the extra 
complication, I think, outweighs the extra expressiveness -- but I 
understand how somebody coming from Ruby, Smalltalk, or FP languages can 
miss such a feature terribly), and I would then have no substantial 
objection to conditionals (the pro's and con's have been well presented -- 
to me, apart from this lambda-related point, the weighted sum is very 
slightly against introducing conditionals, but not enough to make a big 
difference to me either way).

In PEP terms, I think you could summarize this tirade by 
s/function./function (which some would argue is a good think, given the 
current pitiful state of lambda in Python)./ and have done justice to us 
all adversaries of using Python's current lambdas, while staying 
even-handed (as your whole pre-PEP is so admirably) even on this side issue 
of potential relevance.

Alex

From teg at redhat.com  Sun Sep 30 15:13:36 2001
From: teg at redhat.com (Trond Eivind =?iso-8859-1?q?Glomsr=F8d?=)
Date: 30 Sep 2001 15:13:36 -0400
Subject: GNU wars again (was Re: Proposal: add vector arithmetic to array module)
References:  <7x3d5bxhan.fsf@ruckus.brouhaha.com>  <7xzo7jnkjv.fsf@ruckus.brouhaha.com> <9p7kq3$kiu$1@panix3.panix.com>
Message-ID: 

aahz at panix.com (Aahz Maruch) writes:

> In article <7xzo7jnkjv.fsf at ruckus.brouhaha.com>,
> Paul Rubin   wrote:
> >"DeepBlue"  writes:
> >>
> >> This is new to me - if you can not redistribute a distribution in a
> >> modified form, does it mean it is not free?
> >
> >Correct.  See www.gnu.org/philosophy/free-sw.html for explanation.
> 
> Lots of people disagree with this, which is why the phrase "open source"
> has become so much more popular than the GNU view. 

Haven't seen that happening - they're both popular.

Of course, "free" means that you have and can modify the source and I
haven't seen anyone claim that using the term "open source" doesn't
include this. The GPL restricts your freedom to restrict the software
as released by you and is thus "less free" than eg. the XFree86
license. However, that a product has been made with such source
(containing BSD code) does not mean that the end product is free as
they can choose other licenses for the final product.

-- 
Trond Eivind Glomsr?d
Red Hat, Inc.

From emile at fenx.com  Thu Sep 13 07:58:54 2001
From: emile at fenx.com (Emile van Sebille)
Date: Thu, 13 Sep 2001 04:58:54 -0700
Subject: Type conversion mysteries ?
References: 
Message-ID: <9nq81t$95bjk$1@ID-11957.news.dfncis.de>

"Georg Hoermann"  wrote in message
news:qa71qtg73mtf7sb404qnh84r3kbjaf6olp at 4ax.com...
> Hello World,
>
> can someone please explain these results:

It's the order the calculations are done in.

>
> print 100.0*1200/2450   is 48

here you create a float 120000.0 then divide by 2450 to get 48

> print 1200/2450*100.0 gives 0 (zero ?!)

here you integer divide 1200/2450 to get 0 then multiply by 100.0

This will (very likely) change in a futuure release.

>
> Thanks,
> Georg

--

Emile van Sebille
emile at fenx.com

---------

From dgallion1 at yahoo.com  Tue Sep 18 13:53:21 2001
From: dgallion1 at yahoo.com (Darrell)
Date: 18 Sep 2001 10:53:21 -0700
Subject: re source code
References: 
Message-ID: 

Go to
https://sourceforge.net/tracker/?atid=105470&group_id=5470&func=browse
Search for Request ID: 456742 

A full explanation of how this works is beyond me right now.
The work around tries to avoid recursion in favor of a loop.
The problem is that even a loop must make sure that the next char
matches whatever is defined before the '*'.

In the case of '.' this isn't real hard. In the case of "[^\n].*?",
recursion is more attractive.

--Darrell

"Carlos Gaston Alvarez"  wrote in message news:...
> I want to read re source code.
> I want to know why it is more tolerant to .* than to .*?  and so on. The
> final documentation is the source. I want that.
> 
> Chau,
> 
> Gaston
> 
> "Use the source, Luke"

From logiplexsoftware at earthlink.net  Mon Sep 24 17:39:42 2001
From: logiplexsoftware at earthlink.net (Cliff Wells)
Date: Mon, 24 Sep 2001 14:39:42 -0700
Subject: Why so few Python jobs?
In-Reply-To: <00d001c14540$76107ca0$6501a8c0@pacbell.net>
References: <9oltnk$vv3$1@nntp9.atl.mindspring.net>  <00d001c14540$76107ca0$6501a8c0@pacbell.net>
Message-ID: <01092414394200.04862@logiplex1.logiplex.net>

> It's a bit more reasonable to say:
> "Once it's written in Python it's easy to fix."

True, but if I were reasonable, we wouldn't be converting our entire product 
line from SCO/C to Linux/Python ;-)  

-- 
Cliff Wells
Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 x308
(800) 735-0555 x308

From joost_jacob at hotmail.com  Thu Sep  6 15:22:19 2001
From: joost_jacob at hotmail.com (J.Jacob)
Date: 6 Sep 2001 12:22:19 -0700
Subject: Question regarding commenting code
References:  <3B977CA6.4040000@alum.mit.edu>
Message-ID: <13285ea2.0109061122.3d556c9a@posting.google.com>

A very simple rule we found useful is this:
"only comment variables"
Meaning you only explain the "nouns" in your code.  The other code
(the "verbs") should speak for themselves.

If you have a really complex function you can also put an "algorithm"
comment block after the function header, or a "usage" block after a
complex class header.
Other than that it should be enough to describe what a variable does
in your code, and maybe also what it means and why it is used.

We had good experiences using this comment-style-rule in a team.

From nhodgson at bigpond.net.au  Mon Sep 10 21:30:06 2001
From: nhodgson at bigpond.net.au (Neil Hodgson)
Date: Tue, 11 Sep 2001 01:30:06 GMT
Subject: Pythonwin and .NET
References:  <3B997A5E.6010801@bigpond.net.au> <3B9D6654.FA287BA5@earthlink.net>
Message-ID: 

Ron Stephens:

> Mr. Hammond, why is Python on .NET not currently viable? Also, do you
think
> ActiveState will stick with it until it is viable?

   I can't speak for Mark, but my main problem with Python.NET is speed. The
.NET EULA does not allow posting benchmarks but Python.NET is seriously slow
unlike Jython which is comparable to CPython. Currently, if you want to use
Python in a .NET application you may be better off linking to the CPython
interpreter over COM interop.

   Neil

From tim.one at home.com  Wed Sep 26 00:39:41 2001
From: tim.one at home.com (Tim Peters)
Date: Wed, 26 Sep 2001 00:39:41 -0400
Subject: WeakValueDictionary
In-Reply-To: <001501c145fe$0cca9fa0$6401a8c0@pacbell.net>
Message-ID: 

[Ken Seehof]
| >>> sys.version
| '2.1.1 (#20, Jul 20 2001, 01:19:29) [MSC 32 bit (Intel)]'
| >>> import weakref
| >>> d = weakref.WeakValueDictionary()
| >>> d['z']
| Traceback (most recent call last):
|  File "", line 1, in ?
|  File "C:\PYTHON21\lib\weakref.py", line 35, in __getitem__
|    o = self.data.get(key)()
| TypeError: object of type 'None' is not callable
|
| Shouldn't this be raising KeyError instead of TypeError?

It does in current CVS Python:

C:\Code\python\PCbuild>python
Python 2.2a3+ (#23, Sep 20 2001, 19:43:51) [MSC 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import weakref
>>> d = weakref.WeakValueDictionary()
>>> d['z']
Traceback (most recent call last):
  File "", line 1, in ?
  File "C:\CODE\PYTHON\lib\weakref.py", line 44, in __getitem__
    o = self.data[key]()
KeyError: z
>>>

I guess that's what the extra 9 lines of code do .

From mlh at idi.ntnu.no  Fri Sep 28 18:18:26 2001
From: mlh at idi.ntnu.no (Magnus Lie Hetland)
Date: Sat, 29 Sep 2001 00:18:26 +0200
Subject: Sorry!!!!!!!
References: 
Message-ID: <9p2svi$i5l$1@tyfon.itea.ntnu.no>

 wrote in message
news:mailman.1001533132.13660.python-list at python.org...

> The Python collective forgives you!

ROTFLMAO! :)

--

  Magnus Lie Hetland         http://www.hetland.org

 "Reality is that which, when you stop believing in
  it, doesn't go away."           -- Philip K. Dick

From printers at sendme.cz  Sat Sep 29 15:10:54 2001
From: printers at sendme.cz (A)
Date: Sat, 29 Sep 2001 21:10:54 +0200
Subject: How can I access a variable outside a class definition?
Message-ID: <3BB638DE.20838.53CAAE@localhost>

Hi,
How can I access a variable defined in one class outside this class 
? For example

I have two classes like below

#############################
class Complex:
 def __init__(self, realpart1,imagpart1,realpart2,imagpart2):
   self.r1 = realpart1
   self.i1 = imagpart1
   self.r2 = realpart2
   self.i2 = imagpart2
 def Add(self,r1,i1,r2,i2):
   self.sum=self.i1+self.i2
   ImSum=self.sum
   return ImSum
###########################
###########################
class Outside
 def MyFunction(self,ImSum)
  ...
  ...

########################

Is it possible to access,in the Outside class, a value of
the ImSum
that was return by 
Add function in that Complex class?

Thank you for help.
Ladislav

From xavier at perceval.net  Wed Sep 19 08:36:31 2001
From: xavier at perceval.net (Xavier Defrang)
Date: Wed, 19 Sep 2001 14:36:31 +0200 (CEST)
Subject: Size in bytes of a dictionary
Message-ID: 

Dear Pythoneers,

I haven't been able to find a way to get the total size in bytes of a
dictionary object.  I'm writing an application that deals with a large
hashtable (a string-string mapping) and I'd like to be able to monitor its
size in memory.  Is there any heuristic formula I may use depending on the
number of keys and the way the interpreters allocates memory for the data
structure?

Regards,

Xavier Defrang
Perceval R&D Team
xavier at perceval.net

-------------------------------------------------
 Perceval Technologies SA/NV  Tel: +32-2-6409194
 Rue Tenbosch, 9              Fax: +32-2-6403154
 B-1000 Brussels         http://www.perceval.net
 BELGIUM                       info at perceval.net
-------------------------------------------------

From thomas.heller at ion-tof.com  Wed Sep 26 15:01:03 2001
From: thomas.heller at ion-tof.com (Thomas Heller)
Date: Wed, 26 Sep 2001 21:01:03 +0200
Subject: Packaging problem[py2exe, Inno setup] - pywintypes.com_error
References: 
Message-ID: <9ot8lm$fbstf$1@ID-59885.news.dfncis.de>

"Radhika Bodapatla"  wrote in message news:a1d2cfb3.0109261009.183099fc at posting.google.com...
> My application[eclient.py, on winNT4.0] uses
> win32com.client[win32com.client.Dispatch('MSXML2.XMLHTTP'),
> win32com.client.dynamic.Dispatch("Excel.Application")]  and also
> xml.sax for xml parsing.
> I create a setup.py file:
> ;-----setup.py-----------
> from distutils.core import setup
> import py2exe
> setup(name="eclient",
>       scripts=["eclient.py"],
>       data_files=[("template",["expenseform.xls"])],)
> ;------------------------
> I run it using py2exe:
> python setup.py py2exe -p _xmlplus,win32com
> This creates 2folders build and dist. In the dist folder it creates
> eclient folder in which it has the eclient.exe and other .dlls. Also
> creates a folder tcl with 2more folders in it- tcl8.3 and tk8.3.
> Then I use Inno setup[I only include the files in the dist folder] to
> create my .exe so that I can install it on a machine that doesn't have
> python installed on it.
> But this is the error I get when I try to run it from another machine:
> Traceback :
>   File "", line 332, in ?
>   File "", line 12, in __init__
>   File "win32com\client\__init__.pyc, line 94, in Dispatch
>   File "win32com\client\dynamic.pyc, line 81, in
> _GetGoodDispatchandUserName
>   File "win32com\client\dynamic.pyc, line 72, in _GetGoodDispatch
> pywintypes.com_error: (-2147221005, 'Invalid class string', None,
> None)
win32com\client\dynamic, line 72 is
   IDispatch = pythoncom.CoCreateInstance(IDispatch, None, clsctx, pythoncom.IID_IDispatch)

I could be wrong, but doesn't this error say that CoCreateInstance fails
because the COM object you are trying to use is not registered on the other machine?

Thomas

From tim.one at home.com  Tue Sep 18 02:00:09 2001
From: tim.one at home.com (Tim Peters)
Date: Tue, 18 Sep 2001 02:00:09 -0400
Subject: Request for example of state machine using generators
In-Reply-To: 
Message-ID: 

[MikeK]
> I'm trying to learn how to best use Python2.2 generators, and would
> appreciate someone posting an example of a simple state machine using
> generators.

The appeal of generators wrt state machines usually lies in not having to
maintain an explicit state machine at all, so yours is a paradoxical
request.

In 2.2a3 (or CVS), you can look at Tools/scripts/cleanfuture.py for an
extended example of using generators to avoid state machines, there in a
parsing context.  Lib/test/test_generators.py also has many examples of
generator techniques.

From andy.elvey at paradise.net.nz  Wed Sep 26 02:27:15 2001
From: andy.elvey at paradise.net.nz (Andy Elvey)
Date: Wed, 26 Sep 2001 18:27:15 +1200
Subject: lexical closures and python
References: 
Message-ID: <%yes7.10727$ww1.956492@news02.tsnz.net>

John Beppu  wrote in message
news:mailman.999755048.7248.python-list at python.org...
> Hi,
>
> My understanding is that Python does not support lexical closures.
> I've also heard that it should not be expected to appear any time
> in the near future.  Can anyone confirm or deny this?
>
> I want to know, because I'm writing a piece that talks a lot
> about Scheme, and I was comparing it to a lot of scripting languages
> that are out there -- Perl, Python, Ruby, and even JavaScript...
> It seemed strange to me that of all these languages, Python was the
> one that didn't support lexical closures.  (On the other hand, I was
> surpised to find out that JavaScript _did_ support lexical closures).
>
 It *is* indeed possible to do closures in Python !  See this article -
http://www-106.ibm.com/developerworks/library/l-prog.html

 and - http://www-106.ibm.com/developerworks/library/l-prog2.html  .

 ( This is a 2-part article - the second part of it (the 2nd URL given)
shows how to do closures.)
  This article gives an *excellent* intro to functional programming using
Python .   The code in these articles uses the "Xoltar toolkit" -
http://sourceforge.net/projects/xoltar-toolkit  -  which is itself written
in Python.

From -$Paul$- at verence.demon.co.uk  Sat Sep 15 09:16:06 2001
From: -$Paul$- at verence.demon.co.uk (Paul Wright)
Date: 15 Sep 2001 13:16:06 -0000
Subject: idea: Robocode for Python
References:  <9nq2db$3gda$1@mail1.wg.waii.com> <9ntldd$tie$1@mail1.wg.waii.com> 
Message-ID: <9nvkam$khr$1@verence.demon.co.uk>

In article ,
Andrew Henshaw  wrote:
>
>"Martin Franklin"  wrote in message
>news:9ntldd$tie$1 at mail1.wg.waii.com...
>> No, it is: |(java.util.PropertyPermission * read,write)|
>> Preventing Robot Loader from access: (java.util.PropertyPermission *
>> read,write)
>> No, it is: |(java.util.PropertyPermission user.dir read)|
>> Preventing Robot Loader from access: (java.util.PropertyPermission
>user.dir
>> read)
>...snip...
>
>This is a similar results to my efforts.  Interestingly, the permission
>errors seemed to disappear upon reordering the classpath - no idea why.  But
>then, my robot failed as my (your) pyrobot classs wasn't a subclass of
>Robot.  Ooops, I wasn't linking in the robocode.jar.  When I changed that
>back, I could no longer 'jythonc' my code.  Frustrating.  I'll try again
>with a more controlled approach.  Good luck to you.

I'm able to jythonc my code but I get similar errors to those above. I'm
using IBM's JDK 1.3 under Linux.

You can tell whether you've got the classpath right for jythonc as it
prints out whether the robot you've created is a subclass of
robocode.Robot or java.lang.Object.

I think the permissions errors are coming from the Java security
manager: robots are probably not allowed to access the filesystem but
Jython is attempting to access its own cache directory. Knowing very
little about Java or Jython, I don't know whether there's anything we
can do about this.

Did you find an ordering of the classpath which would enable you to run
jythonc correctly and avoid the permission errors?

On the licence issue, the author notes that there is nothing in the
licence preventing you from downloading again after the 90 days are up
(hint, hint). He also states that as the thing is in quite rapid
development, you'll want to get updates anyway.

-- 
----- Paul Wright ------| This may seem a bit weird, but that's okay, because
-paul.wright at pobox.com--| it is weird.  - Perl 5 manpages
http://pobox.com/~pw201 | 

From barry at zope.com  Mon Sep 17 01:28:33 2001
From: barry at zope.com (Barry A. Warsaw)
Date: Mon, 17 Sep 2001 01:28:33 -0400
Subject: ANNOUNCE mimelib 0.5
Message-ID: <15269.35329.201238.946022@anthem.wooz.org>

I've just released mimelib 0.5, a package for handling email messages,
including MIME documents.  This version contains lots of new features,
bug fixes, and unit tests.  See below for a NEWS file excerpt.

This will likely be the last independent release of mimelib.  I intend
to merge it into the Python standard library for Python 2.2 alpha 4.
There will be changes due to the merge, including a new name for the
package (`email' It Shall Be Called), and some shuffling of modules
and method names.

The current Mailman 2.1 alpha and CVS snapshot has not been tested
with this release, and there are likely some breakages.  The next
Mailman alpha release /will/ be made compatible, and if any bugs crop
up at that point, there may have to be an 0.6 release.  I hope not
though.

The mimelib projects page at SourceForge (includes links for
downloading):

    http://sf.net/projects/mimelib

The online manual:

    http://mimelib.sf.net

Cheers,
-Barry

-------------------- snip snip --------------------
0.5 (17-Sep-2001)

    - New methods in the top-level mimelib package namespace:
        + messageFromString() to create an object tree from a string.
        + messageFromFile() to create an object tree from an open file.

    - New methods in the address.py module:
        + encode() for encoding to RFC 2047 headers
        + decode() for decoding from RFC 2047 headers

    - New methods in the Message class:
        + asString() to get a flat text representation of the object
          tree.
        + __str__() same as asString() but includes the Unix-From
          envelope header in the output.
        + __contains__() for use with the `in' operator.
        + attach() is a synonym for add_payload()
        + getcharsets()
        + getfilename()
        + getboundary()
        + setboundary()
        + getdecodedpayload()
        + getpayloadastext()
        + getbodyastext()

    - Message.preamble and Message.epilogue default to None (they used
      to not exist by default).

    - Changes to the Generator class:
        + New optional argument `maxheaderlen' for __init__() controls
          the maximum length in characters of any header line.
        + write() isn't the entry point for doing the text generation
          any more.  This lets us make this method compatible with
          file-like objects.  Use __call__() semantics instead.
        + Calling a Generator instance creates the plain text
          message.  This is the same as the old write() interface
          except that the optional `unixfrom' argument now defaults to
          0.
        + There is a new, undocumented semi-private interface for
          extending the MIME types Generator can handle.  UTSL.

    - New Encoders.py module contains some useful encoders for Image
      and Text instances.

    - Text.__init__() has a new _encoder optional argument, which has
      the same semantics as _encoder for Image.__init__().

    - StringableMixin.py module has been removed, and its
      functionality merged back into the Message class.

    - MessageParseError doesn't contain line numbers any more.

    - Lots of bug fixes; lots more unit tests.

From ignacio at openservices.net  Thu Sep 20 17:52:24 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Thu, 20 Sep 2001 17:52:24 -0400 (EDT)
Subject: Ksh-ish functionality on Unix systems
In-Reply-To: <1001022297.843756@cswreg.cos.agilent.com>
Message-ID: 

On Thu, 20 Sep 2001, Greg Weeks wrote:

> The low-level support is far too verbose for casual use.  The higher-level
> stuff seems incomplete.  However, the higher-level stuff becomes a lot more
> complete if the command arguments are passed to, say, /bin/sh on Unix
> systems.  In that case, os.system and getstatusoutput capture the above Ksh
> functionality, and os.popen and popen2.* are bonuses.
>
> So: Is it a reasonable approach as a Unix user to rely on the fact that the
> os.system and getstatusoutput commands are passed to a shell?
>
> Or is that tacky?  If that *is* tacky, is there a *convenient* alternative?

Yeah, that's tacky. No, there are no convenient alternatives. Looks like
you're stuck with popen*(), fork(), and the threading module.

-- 
Ignacio Vazquez-Abrams  

From logiplexsoftware at earthlink.net  Fri Sep  7 15:02:47 2001
From: logiplexsoftware at earthlink.net (Cliff Wells)
Date: Fri, 7 Sep 2001 12:02:47 -0700
Subject: Creating Excel files on Linux
In-Reply-To: 
References: <3B97A39C.6A5234D7@olen.to> <873d5ygbzx.fsf@lumen.med.iupui.edu> 
Message-ID: <01090712024702.02565@logiplex1.logiplex.net>

On Friday 07 September 2001 10:30, you wrote:

> This is fine.  But in my experience, the average user can create a Macro
> and be trained to create useful forms in Excel in a much shorter time than
> it will take to get a Computer Science degree in order to be able to step
> through a JAVA function.

No, the _above_ average user can do this.  The average user doesn't know that 
Excel isn't Windows.

> The issue here Michael, in my opinion, is that many attack Microsoft on the
> premise of the MYTH of an open platform that is being called on by many
> sides including companies that would not give a dime about this concept if
> they have the same market share as Microsoft.
> Maan

Yes, when IBM gets as big as Microsoft, they'll want their billion dollars 
back.

-- 
Cliff Wells
Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 x308
(800) 735-0555 x308

From sill at optonline.net  Wed Sep 26 18:21:05 2001
From: sill at optonline.net (Andrei Kulakov)
Date: Wed, 26 Sep 2001 22:21:05 GMT
Subject: scanf style parsing
References: <3BB16A50.BAE082FE@cygnus-software.com>
Message-ID: 

On Wed, 26 Sep 2001 05:42:45 GMT, Bruce Dawson  wrote:
> I love programming in Python, but there are some things I have not found
> the easy way to do. I understand that Python is supposed to be good at
> text parsing, but I am having trouble with this simple task. Given this
> text (the output from VisualC++) I want to find out how many errors and
> warnings there were:
> 
> smtpmail.exe - 0 error(s), 0 warning(s)

Seeing that there should only be 2 words here that are numbers, you can do
this:

my_str # that's where the result is
words = my_str.split()
lst = []
for word in words:
    try:
        result = int(word)
        lst.append(result)
    except:
        pass

errors = lst[0]
warnings = lst[1]

I'm not sure how can this format vary, but if these numbers are always at
the same place, you could have just done:

errors, warnings = int(words[2]), int(words[4])

- Andrei 

-- 
Cymbaline: intelligent learning mp3 player - python, linux, console.
get it at: cy.silmarill.org

From peter at engcorp.com  Tue Sep 25 00:26:14 2001
From: peter at engcorp.com (Peter Hansen)
Date: Tue, 25 Sep 2001 00:26:14 -0400
Subject: Using glob (was Re: Remove files of same type (extension))
References: <9on1mq$pj8$04$1@news.t-online.com> <3BAF3754.68BDA949@yahoo.com> 
Message-ID: <3BB00766.CC23290C@engcorp.com>

Marcin 'Qrczak' Kowalczyk wrote:
> 
> Mon, 24 Sep 2001 17:38:28 +0400, A.A  pisze:
> 
> > You can use the fnmatch module to match using dos/unix like patterns:
> 
> Or the glob module.

I used to think glob was a good choice, and simpler than os.listdir
plus os.path.walk etc because it would handle things like */*.txt and
returned the full path.

I just got caught, however, by my apparent lack of understanding of
the phrase "according to the rules used by the Unix shell" from 
the library reference info on glob.

glob.glob('*') returns all files *except* those that start with a period

glob.glob('.*') returns all files which do start with a period.

To use glob to get *all* files, one must do something like

  glob.glob('*') + glob.glob('.*')

I'd be happy to learn otherwise, but that's what reading the 
source confirmed for me...

Still easier than os.listdir sometimes, but I wonder if it should
be considered rather specialized.  Or was that already the general
consensus?

-- 
----------------------
Peter Hansen, P.Eng.
peter at engcorp.com

From phr-n2001 at nightsong.com  Thu Sep 13 00:46:53 2001
From: phr-n2001 at nightsong.com (Paul Rubin)
Date: 12 Sep 2001 21:46:53 -0700
Subject: What is Python good for?
References: <6f8cb8c9.0109120541.132432d4@posting.google.com>  <3BA0293F.F558764A@engcorp.com>
Message-ID: <7xbskfitoi.fsf@ruckus.brouhaha.com>

Peter Hansen  writes:
> I wonder whether Python is hands down the best "glue" language.
> ...
> Does anything else come even close?

The main competition is Perl, which has a much deeper component
library (cpan.org) and more slick little shorthand devices.
Perl is of course much clumsier for writing large maintainable
programs.

From aleax at aleax.it  Fri Sep 21 14:59:00 2001
From: aleax at aleax.it (Alex Martelli)
Date: Fri, 21 Sep 2001 20:59:00 +0200
Subject: python version
References: 
Message-ID: <9og2lk$o1k$1@lancelot.camelot>

Bob Roberts wrote:

> How can a python program find out what version of python it is running?

>>> import sys
>>> print sys.version
2.2a3 (#1, Sep 11 2001, 23:11:58)
[GCC 2.96 20000731 (Linux-Mandrake 8.0 2.96-0.48mdk)]
>>> print sys.version_info
(2, 2, 0, 'alpha', 3)
>>> print sys.hexversion
33685667
>>> print hex(sys.hexversion)
0x20200a3
>>>

Alex

From aleax at aleax.it  Mon Sep  3 11:22:13 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 3 Sep 2001 17:22:13 +0200
Subject: typechecks: just say no! (was Re: Determining Types)
References:  <9mvo0u04o8@enews2.newsguy.com> <3b938f31.2123170@nntp.sprynet.com>
Message-ID: <9n077501por@enews1.newsguy.com>

"David C. Ullrich"  wrote in message
news:3b938f31.2123170 at nntp.sprynet.com...
    ...
> But in other places it's good to be able to refer to
> fields with non-literal names, so I add a __getitem__
> so that rec['thisfield'] returns rec.thisfield.
    ...
> In yet other places I want to iterate over the fields
> of a record, as in
>
> for key, value in rec:
>
> So in __getitem__ I check the type of index, returning
> getattr(self, index) if index is a string and saying
>
> fieldname=self.__fieldnames__[index]
> return (fieldname, getattr(self, fieldname))
>
> if index is an integer.
>
> Seems utterly keen to be able to use them as both
> lists and as mappings, as needed.

Matter of taste (I personally don't much like any
confusion between attributes and items), and in Python
2.2 a far better solution is provided (the for statement
will first attempt to use the __iter__ method -- just
implement *that* one to return the iterator you want,
and note that for a built-in dictionary
    for x in dict
only iterates on KEYS, *not* key-value pairs, so,
take care to avoid any confusion...).  Admittedly,
being able to index a Collection on EITHER item
name or item number IS a typical Visual Basic
feechur, but that still doesn't much recommend it
to my personal taste.  Anyway...:

If I had to implement this in Python 2.1 or earlier,
I'd use either variant of "it's easier to get
forgiveness than permission", which after all IS
the typical idiom to use where the unenlightened
would typetest: i.e., either:

def __getitem__(self, index):
    try: return getattr(self, index)
    except AttributeError:
        fieldname=self.__fieldnames[index]
        return fieldname, getattr(self, fieldname)

or:

def __getitem__(self, index):
    try:
        fieldname=self.__fieldnames[index]
    except TypeError:
        return getattr(self, index)
    else:
        return fieldname, getattr(self, fieldname)

This would let client-code use any "index" that is
string'ish enough to please getattr, or int'ish
enough to please the [] indexing on __fieldnames
(don't use double leading AND trailing __ for your
own purposes, they're all "reserved to Python"!-).

Alex

From mikael at isy.liu.se  Tue Sep  4 03:48:13 2001
From: mikael at isy.liu.se (Mikael Olofsson)
Date: Tue, 04 Sep 2001 09:48:13 +0200 (MET DST)
Subject: Conditional operator in Python?
In-Reply-To: <9n1vir$chl$1@glue.ucr.edu>
Message-ID: 

On 04-Sep-2001 thp at cs.ucr.edu wrote:
 >  Okay, factorial is a somewhat simplistic example.  Consider the
 >  following function, which counts the k-way partitions of n:
 >  
 >    p = lambda k, n : (
 >        ( k < 1  or k > n  ) and [0] or 
 >        ( n == 1 or n == k ) and [1] or 
 >        [p(k-1,n-1)+p(k,n-k)] 
 >      )[0]
 >  
 >  Using, say, ?: notation this would be written:
 >  
 >    p = lambda k, n : 
 >      k < 1  or k > n  ? 0 :
 >      n == 1 or n == k ? 1 :
 >      p( k-1, n-1 ) + p (k, n-k )
 >  
 >  which seems much more concise and readable.

Well, both are just as hard to read to me, but then I have never used 
C. I (almost) always use if-then-else, since that fits my small brain 
best. Sure, it needs more rows, but I prefer that to both variations of
line noise above.

/Mikael

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Telefax: +46 - (0)13 - 28 1339
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Time:    09:38:44

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From logiplexsoftware at earthlink.net  Wed Sep 19 15:31:43 2001
From: logiplexsoftware at earthlink.net (Cliff Wells)
Date: Wed, 19 Sep 2001 12:31:43 -0700
Subject: optional arguments
In-Reply-To: 
References:  
Message-ID: <01091912314300.03077@logiplex1.logiplex.net>

On Monday 17 September 2001 02:52, Martin von Loewis wrote:
> Silvio Arcangeli  writes:
> > class Connection:
> > 	def __init__(self, ip=def_ip, port=def_port)
> > 		...
>
> [...]
>
> > how can I tell wheter no arguments were passed from the user or whether
> > they were passed but they were just like the default values?
>
>

Another possibility is mxTools which provides a NotGiven singleton similar to 
None:
(from the mxTools page):

import mx.Tools.NewBuiltins
def f(a,b=4,c=NotGiven,d=''):
    if c is NotGiven:
        return a / b, d
    else:
        return a*b + c, d

http://www.lemburg.com/files/python/mxTools.html

-- 
Cliff Wells
Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 x308
(800) 735-0555 x308

From skip at pobox.com  Wed Sep 12 17:06:12 2001
From: skip at pobox.com (Skip Montanaro)
Date: Wed, 12 Sep 2001 16:06:12 -0500
Subject: math.frexp - what's it mean?
In-Reply-To: 
References: 

Message-ID: <15263.52804.991188.533242@beluga.mojam.com>

    >>> mantissa, exponent = math.frexp(5e40)

Not being a numeric type person, "frexp" conjured up absolutely no mnemonic
significance for me.  The library reference manual was no help either.
Finally, I tried "man frexp" and got "convert floating-point number to
fractional and integral components".  Now I know what it means mnemonically
("FRaction EXPonent", I guess), but the name is still perplexing.  Why not
"manexp"?  Does its use predate its appearance in C?

Skip

From qrczak at knm.org.pl  Tue Sep  4 12:50:48 2001
From: qrczak at knm.org.pl (Marcin 'Qrczak' Kowalczyk)
Date: 4 Sep 2001 16:50:48 GMT
Subject: Conditional operator in Python?
References:  <9n1vir$chl$1@glue.ucr.edu>   <3B94F000.64D06161@alcyone.com>  <3B94FF7B.53B929BE@alcyone.com>
Message-ID: 

Tue, 04 Sep 2001 09:21:15 -0700, Erik Max Francis  pisze:

> Maybe something like
> 
> 	if X return Y else Z

Or
    if (X) Y else Z
which looks like statement if without colons (but parens are required).

> I wouldn't be averse to introducing a new keyword for this purpose,
> but if that's the stumbling block, it seems that a preexisting
> keyword can be used in this context that will work just as well.

At least I don't see other problems (and other than "it's unnecessary
feature bloat").

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZAST?PCZA
QRCZAK

From Tobias_Unruh at FRM2.TU-Muenchen.DE  Wed Sep  5 11:18:20 2001
From: Tobias_Unruh at FRM2.TU-Muenchen.DE (Tobias Unruh)
Date: Wed, 5 Sep 2001 17:18:20 +0200 (CEST)
Subject: no parallel threading?
Message-ID: 

Hi,

I tried to execute two threads in parallel (linux 2.4.9, python 2.0):

import time
import threading

def test_thread_func1():
    print "Hallo1"
    time.sleep(3.0)
    print "Hallo1"

def test_thread_func2():
    print "Hallo2"
    time.sleep(3.0)
    print "Hallo2"

printlock = threading.Lock()

test_thread1 = threading.Thread(None,test_thread_func1())
test_thread2 = threading.Thread(None,test_thread_func2())

print "number of active threads: %d" % threading.activeCount()

test_thread1.start()
test_thread2.start()

print "number of active threads: %d" % threading.activeCount()

while test_thread1.isAlive()==1:
    continue

print "number of active threads: %d" % threading.activeCount()

The output of the program is:

Hallo1
Hallo1
Hallo2
Hallo2
number of active threads: 1
number of active threads: 3
number of active threads: 1

Why this result? From the first four lines I concluded that the threads
are executed one after the other (which is not intended). In this case,
however, the number of active threads should be 1 in any case. But these
values are ok. Is there something wrong with the output?
sys.stdout.flush() does not help.

Any suggestions?

Tobias

--
Tobias Unruh
TU Muenchen, FRM-II
85747 Garching, Germany

From martin.franklin at westgeo.com  Fri Sep 14 04:43:50 2001
From: martin.franklin at westgeo.com (Martin Franklin)
Date: Fri, 14 Sep 2001 09:43:50 +0100
Subject: create documentation with the comments present in the source code
References: <9nsdkl$s3q$1@s1.read.news.oleane.net> 
Message-ID: <9nsfsb$2ctu$1@mail1.wg.waii.com>

Dietmar Lang wrote:

> Hi!
> 
>> As it is possible to put comment in 'python' code just after a function,
>> a class as following :
>> 
>> def Function():
>>     """
>>     My comment
>>     """
>>     if ...
>> 
>> As it is possible to get this comment in the python command with an
>> simple instruction...
> 
> Yes, here's a little interactive session:
> 
>>>> def Voila():
> """This is documentation for Voila()"""
> pass
> 
>>>> print Voila.__doc__
> This is documentation for Voila()
>>>> 
> 
> There you go... If more details are needed, maybe someone here will jump
> in...
> 
>> Is there an utility which realize a pretty documentation with these
>> comments ?
> 
> There propably is, else why don't you make one? ;)
> 
> Kudos, Dietmar
> 

Take a look at HappyDoc this will create static HTML documentation from  
doc strings search the vaults http://www.vex.net/parnassus/

From qrczak at knm.org.pl  Tue Sep  4 04:27:09 2001
From: qrczak at knm.org.pl (Marcin 'Qrczak' Kowalczyk)
Date: 4 Sep 2001 08:27:09 GMT
Subject: Conditional operator in Python?
References:  <9n1vir$chl$1@glue.ucr.edu>
Message-ID: 

Tue, 4 Sep 2001 07:24:13 +0000 (UTC), thp at cs.ucr.edu  pisze:

> Using, say, ?: notation this would be written:
> 
>   p = lambda k, n : 
>     k < 1  or k > n  ? 0 :
>     n == 1 or n == k ? 1 :
>     p( k-1, n-1 ) + p (k, n-k )
> 
> which seems much more concise and readable.

IMHO this would look more clearly:

    p = lambda k, n:
      if k < 1  or k > n  then 0 else
      if n == 1 or n == k then 1 else
      p( k-1, n-1 ) + p (k, n-k )

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZAST?PCZA
QRCZAK

From rnd at onego.ru  Wed Sep  5 15:00:18 2001
From: rnd at onego.ru (Roman Suzi)
Date: Wed, 5 Sep 2001 23:00:18 +0400 (MSD)
Subject: no parallel threading?
In-Reply-To: 
Message-ID: 

On Wed, 5 Sep 2001, Tobias Unruh wrote:

>> On Wed, 5 Sep 2001, Tobias Unruh wrote:
>
>def test_thread_func1():
>    k=0L
>    print "hello1"
>    for i in range(1000000):
>        k=k+1
>    print "hello1"

Put hello into the loop and another delay loop.

    for i in range(20):
      print "hello1"
      for i in range(100000):
        k=k+1

>but nothing changed.
>
>I installed now Python 2.2.a2. But again the same problem...
>
>Do I have it to write in C++?
>
>>
>> BTW, this is what intrigued Linus most and was supported from the very
>> first version of Linux ;-) (in processes, of course, not threads)

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Wednesday, September 05, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "... Clinton sandwich: $5 of baloney and $20 in taxes" _/

From g.haering at ___skynamics.com.invalid  Wed Sep  5 12:01:06 2001
From: g.haering at ___skynamics.com.invalid (Gerhard =?ISO-8859-1?Q?H=E4ring?=)
Date: Wed, 05 Sep 2001 18:01:06 +0200
Subject: Where does my output go?
References:   
Message-ID: <3B964C42.9020407@___skynamics.com.invalid>

Michael Abbott wrote:
> "Maan M. Hamze"  wrote in 
> news:tpcfiohb7crq2c at corp.supernews.com:
> 
>>"Michael Abbott"  wrote in message
>>news:Xns91139DA18A194michaelrcpcouk at 194.238.50.13...
>>
>>>So, I write a small bit of Python (one line):
>>>
>>>write.py
>>>--------
>>>    print 'hello'
>>>--------
>>>
>>>I then run it from the command line:
>>>
>>>    C:\TEMP>write
>>>    Hello
>>>
>>>
>>I do not understand this step here.  How are you running write as an
>>executable? and why is it printing Hello not hello?
>>
> 
> Oops.  My mistake.  I cut and pasted the output, but unfortunately, I 
> didn't cut and paste the source code!  The source code should, of course, 
> be
> 
>     	print 'Hello'
> 
> As to why running it from the command line (with or without a .py 
> extension) works?  Indeed, that is a mystery, one of the many mysteries of 
> this marvellous operating system we use.
>     	It's something to do with how the .py extension is registered, I know 
> that much.
> 

C:\temp\e>copy con: write.py
print "Hello."
^Z
         1 Datei(en) kopiert.
C:\temp\e>write.py
Hello.
C:\temp\e>write.py >out.txt
C:\temp\e>type out.txt
Hello.
C:\temp\e>echo %OS%
Windows_NT

Actually version 5 SP2 aka Windows 2000. Windows 9x/ME console is known 
to be buggy.

Gerhard
-- 
Gerhard H?ring
skynamics AG
g.haering at skynamics.com
http://www.skynamics.com

From jeff at ccvcorp.com  Fri Sep 28 16:20:23 2001
From: jeff at ccvcorp.com (Jeff Shannon)
Date: Fri, 28 Sep 2001 13:20:23 -0700
Subject: Why so few Python jobs?
References: <9oltnk$vv3$1@nntp9.atl.mindspring.net>
Message-ID: <3BB4DB87.8600869E@ccvcorp.com>

tszeto wrote:

>
> Any ideas on why so few Python jobs are available?
>

My take, in addition to the many good reasons already mentioned, is that
Python is so easy to learn, that when it *is* appropriate to use, it's usually
simpler for the existing staff to learn Python as well (or for an otherwise
qualified recruit to be taught Python), than to specifically hunt for someone
already skilled in Python.

Of course, if the company has a need for a *very* skilled Python programmer,
then hiring specifically for that skill becomes reasonable.

Jeff Shannon
Technician/Programmer
Credit International

From parker at gol.com  Mon Sep 17 17:46:01 2001
From: parker at gol.com (Ian Parker)
Date: Mon, 17 Sep 2001 21:46:01 GMT
Subject: COM and printing an Acrobat
References: 

Message-ID: 

In article , Ignacio
Vazquez-Abrams  writes
>On Sat, 15 Sep 2001, Ian Parker wrote:
>
>> Unfortunately, I'm a bit stuck on how to print Acrobat files.  Acrobat 4
>> provides an ActiveX control intended for use in IE, but I'm stumped how
>> to make use of it to print.
>>
>> Any ideas?
>
>Sucks to be you:
>
>  http://www.adobe.com/support/techdocs/cd16.htm
>

It does indeed.  That URL does point out that the ActiveX control is of
restricted functionality.  Currently, I remain stumped and almost out of
time!

Regards

Ian
-- 
Ian Parker

From fredrik at pythonware.com  Wed Sep  5 04:25:38 2001
From: fredrik at pythonware.com (Fredrik Lundh)
Date: Wed, 05 Sep 2001 08:25:38 GMT
Subject: string.split
References: 
Message-ID: <6kll7.895$sn6.205073@newsc.telia.net>

Tom Harris wrote:
> How do I split on any or all occurrences of (for example)
> whitespace and a comma, without using regexes.

are you interested in results, or are you just trying to make
python fit your mental model?

if the former, this does what you want:

    L = re.split("[\s,]+", S)

or faster, in the current version:

    L = re.findall("[^\s,]+", S)

if you're going to do lot of splitting, create a splitter object:

    mysplit = re.compile("[^\s,]+").findall

    L = mysplit(S)

> I mean string.split() must be able to do it anyway to achieve
> the default behaviour.

split uses different algorithms depending on the second argument
(the unicode type has three different implementations)

From dalke at dalkescientific.com  Thu Sep 20 23:20:36 2001
From: dalke at dalkescientific.com (Andrew Dalke)
Date: Thu, 20 Sep 2001 21:20:36 -0600
Subject: bsddb3 vs zodb
References: <3BA9A72A.1D5A6067@yahoo.com> <3BA9EBFD.3F7ABFFA@engcorp.com>
Message-ID: <9oebkq$8k6$1@slb4.atl.mindspring.net>

Peter Hansen:
>Isn't DB3 a relational database?  Since ZODB is clearly not,
>we're going to end up just comparing the "pros and cons" of
>relational versus object-oriented databases, I think.

DB2 is a relational database from IBM.

dbm/ndbm/gdbm/Berkeley DBM/Sleepcat BSDDB are all
associative databases.  (I just made up that term. :)
They associate a key (a string) to a value (another
string).

For example, a mail server needs to know how to expand
an email alias into a set of addresses.  So it needs the
mapping
  alias -> list,of,email,addresses
and a fast way to look it up.

It doesn't need a full relational database, nor SQL.
Just simple key/value storage and lookup.

BSDDB3 is the 3'rd major release of BSDDB, the Berkely
DBM being developed by Sleepycat.  It offers a lot of
functionality.

                    Andrew
                    dalke at dalkescientific.com

From weeks at vitus.scs.agilent.com  Tue Sep 25 22:31:22 2001
From: weeks at vitus.scs.agilent.com (Greg Weeks)
Date: Wed, 26 Sep 2001 02:31:22 +0000 (UTC)
Subject: Simple process IO capture (Was: "shell-commands" and python!) - process.py (0/1)
References: <9ogit0$e7c$1@newshost.accu.uu.nl>    <1001306463.868543@yabetcha.drizzle.com>
Message-ID: <1001471482.175819@cswreg.cos.agilent.com>

I guess there isn't a lot of interest in this.  Still, I'm interested.

Donn Cave (donn at drizzle.com) wrote:
: Are you thinking about reading stderr for use in the exception?

stderr is a messy issue, because there is no agreement on what stderr is
for.  Some people use stderr only for fatal error messages.  Othere use
stderr -- now renamed "diagnostic output" -- for any messages whatsoever
intended for human readers.  The first group is like to want exceptions to
include stderr text; the second group isn't.

I'm in the first group, and I'm content to write a private utility that
handles stderr as if it were used only for fatal error messages (even
though I know this will get me into trouble with certain programs).  But
I'd be hard-pressed to come up with a general solution.  Look at the
evolution of the popen2 module, for instance.  And if you have a pipeline
with multiple processes, it just gets that much worse.

Greg

From beppu at binq.org  Wed Sep 12 17:49:36 2001
From: beppu at binq.org (John Beppu)
Date: Wed, 12 Sep 2001 14:49:36 -0700
Subject: What is Python good for?
In-Reply-To: <9nnsck02uat@enews1.newsguy.com>
References: <6f8cb8c9.0109120541.132432d4@posting.google.com> <9nnsck02uat@enews1.newsguy.com>
Message-ID: <20010912144936.D18903@BinQ.org>

[  date  ] 2001/09/12 | Wednesday | 04:44 PM
[ author ] Alex Martelli  

> If you think Perl is easy to master, then you're a very unusual
> sort of person.  

Not necessarily unusual -- just different from you.

My background in /bin/sh and C programming made perl
really easy, because it just felt like perl fit
right in the middle.  I can't say perl was very hard
for me to learn

...and I'm not /that/ unusual...  I think.  ;-)

From markus at schabi.de  Thu Sep 27 04:54:29 2001
From: markus at schabi.de (Markus Schaber)
Date: Thu, 27 Sep 2001 10:54:29 +0200
Subject: Are there 'Interfaces' in Python??
References:  
Message-ID: <1960596.2OnDr8pfo1@lunix.schabi.de>

Hi,

Lee Morgan  schrub:

> I don't understand what runtime interfaces get you at all. From my
> distant memory of Java a class implements an interface, and therefore
> guarantees its existence.
> 
> Ah haa - maybe I get it now, do you mean python interface's would
> supply the base interface which you could override? And if so wouldn't
> the type/class unification provide a cleaner way of doing it? Or would
> an interface just guarantee some base class's __init__ is called?
> 
> Hmm, I should really read the Interface PEP!

I would agree.

As far as I remember, you ask the object in question to give you a 
specific interface, and the object returns an instance that is 
guaranteed to implement the interface (could be the object itsself or a 
wrapper). When this fails, maybe the interface itsself knows how to 
wrap around the object and can create such one.

markus
-- 
"The strength of the Constitution lies entirely in the determination of 
each citizen to defend it. Only if every single citizen feels duty 
bound to do his share in this defense are the constitutional rights 
secure." -- Albert Einstein

From padhia at yahoo.com  Tue Sep 18 10:55:23 2001
From: padhia at yahoo.com (P Adhia)
Date: 18 Sep 2001 07:55:23 -0700
Subject: newbie - Scoping question
References: <3281a460.0109170759.63ede66@posting.google.com>
Message-ID: <3281a460.0109180655.6a9c21f5@posting.google.com>

Thanks everyone for your help. 

Now it makes perfect sense. Indeed, it has nothing to do with scoping.
(Though I wish it had :) - it's probably more intuitive to me).

P. Adhia

From loewis at informatik.hu-berlin.de  Tue Sep 18 13:30:09 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 18 Sep 2001 19:30:09 +0200
Subject: The nntplib module
References: <9o7qqd03vm@enews1.newsguy.com>
Message-ID: 

"Travers Naran"  writes:

> I'm working on a newsgroup binaries extractor (which works well under
> Windows and LINUX), and I'm finding the nntplib doesn't have that nice
> feature the Perl NNTP module has of downloading an article body to a file.
> I've modified my local copy of nntplib to handle this, but I can't find any
> reference to who is maintaining this module so I can make this suggestion.
> Who should I contact?  Thanks in advance!

It's part of the standard Python library, so patches should go to
sf.net/projects/python. If you feel that your changes might be
controversial, write a PEP.

> On a side note, I've found running my script under Linux (same wintel box)
> much faster than running under Windows 98.  I suspect it's the difference in
> Virtual Memory performance, but I can't prove this.  Discuss amongst
> yourselves. :-)

My guess is that it is more likely the efficiency of the TCP stack.

Regards,
Martin

From pete at visionart.com  Thu Sep 13 18:58:24 2001
From: pete at visionart.com (Pete Shinners)
Date: Thu, 13 Sep 2001 15:58:24 -0700
Subject: Proposed PEP for a Conditional Expression
References: 
Message-ID: <3BA13A10.8080108@visionart.com>

>>  if  else 
> 
> But that appears to NOT scan like English.
> "one if by land two if by sea"

num_rings = 1 if enemy.onland() else 2

not the most graceful english, heh. and i suppose
it works if they are nested..

num_rings = 1 if onland() else 2 if onsea() else 3

From aahz at panix.com  Thu Sep  6 22:43:57 2001
From: aahz at panix.com (Aahz Maruch)
Date: 6 Sep 2001 19:43:57 -0700
Subject: Performance of list comprehensions vs. map
References: <3B966B1C.120D0AF6@home.net> <3B96C062.99E36B04@home.net>  <3B97EB8D.D64CE8F0@home.net>
Message-ID: <9n9c9d$cl1$1@panix2.panix.com>

In article <3B97EB8D.D64CE8F0 at home.net>,
Chris Barker   wrote:
>Skip Montanaro wrote:
>>
>> You're more than welcome to write a PEP.
>
>The reason I havn't is that I am in no position to impliment even a
>prototype of the idea (both time and skills), and unless someone who is
>in that position takes some interest, there really isn't any point. It
>also may be a just plain bad idea, so I would like more feedback before
>I went that far. Thanks for your input, I have certainly learned from
>this discussion.

You may want to bring this up on python-dev; most of the core developers
(except for Tim) pay little attention to c.l.py these days.  Also, the
whole point of a PEP is to formalize the feedback process; you do *not*
need to be in a position to implement it.
-- 
                      --- Aahz  <*>  (Copyright 2001 by aahz at pobox.com)

Hugs and backrubs -- I break Rule 6                 http://www.rahul.net/aahz/
Androgynous poly kinky vanilla queer het Pythonista   

"Plus ca change, plus c'est la meme chose."

From on_the_net at clear.net.nz  Wed Sep  5 16:37:11 2001
From: on_the_net at clear.net.nz (Rob Brown-Bayliss)
Date: Thu, 06 Sep 2001 08:37:11 +1200
Subject: appropriate graphics Lib?
References:   
Message-ID: <20010906.083658.1671294892.25599@clear.net.nz>

In article , "Pete Shinners"
 wrote:

> if you decide to go with pygame, i'd be glad to help out :] but don't
> let that rule out pyopengl first, especially the higher level object
> stuff that mike mentioned in an earlier post.

Has anyone used pygame embeded in a pygnome window (prefer glade setup)?  

I am just starting on a project, and thought about useing the gnome
canvas widget, but as the project evolves (it's not a game as such) the
mixing of sound to the actions in the window could be useful.

-- 

  Rob Brown-Bayliss
 ---======o======---

From martin.franklin at westgeo.com  Fri Sep 28 10:50:01 2001
From: martin.franklin at westgeo.com (Martin Franklin)
Date: Fri, 28 Sep 2001 15:50:01 +0100
Subject: Problem with os.system()
References: <3bb480af_1@news.newsgroups.com> 
Message-ID: <9p22io$5jbi$1@mail1.wg.waii.com>

Terry Reedy wrote:

> 
> "Janos Blazi"  wrote in message
> news:3bb480af_1 at news.newsgroups.com...
>> I have the following code:
>>
>>     prog=r'"C:\Programme\Windows Media Player\mplayer2"'
>>     f=r'c:\WINNT\Media\Microsoft Office 2000\APPLAUSE.WAV'
>>     os.system(prog+' /Play '+f)
>>
>> Now first it seems as though it worked and the wav file is played.
> The
>> problem is that after the wav file has ben played my program does
> not regain
>> the control i.e. the next statement is not executed. If I close the
> Media
>> Player window manually, my program resumes. I use Win2000 but my
> program
>> should work under MS-DOS.
> 
> Your 'problem' is not with your Python program, but with mplayer not
> closing itself by itself after playing one song.  Perhaps there is a
> command line option that would tell it to do so.  Perhaps you should
> find a wav-file player that behaves better for your purpose.  I
> believe that pygame may give you access to some such.
> 
> Terry J. Reedy
> 
> 
> 

You could also try winsound (part of the standard lib)

import winsound

fil='c:/WINNT/Media/Microsoft Office 2000/APPLAUSE.WAV'

winsound.PlaySound (file, winsound. SND_FILENAME)

From lunatic at beyond.net  Fri Sep 14 17:59:24 2001
From: lunatic at beyond.net (LunaTic)
Date: Fri, 14 Sep 2001 23:59:24 +0200
Subject: Namespace confusion
References: <9nssgi$oiv$1@news.netcologne.de>
Message-ID: <9ntukf$i0j$07$1@news.t-online.com>

Thank you all for your insightful comments, in particular thanks to Martin 
von Loewis for his detailed explanations!

Regards

From stevena at neosynapse.net  Thu Sep 20 04:07:03 2001
From: stevena at neosynapse.net (Steven D. Arnold)
Date: Thu, 20 Sep 2001 04:07:03 -0400
Subject: problems with re in binary files
Message-ID: <43103304954.20010920040703@neosynapse.net>

Hi,

I'm trying to parse a binary file using the re module.  At one point I
use '<<(.*)>>' with the r.DOTALL option.  I expect this to find a '<<'
string, find the last '>>' string in the string (which contains the
whole document; it's small), and everything between would go in the
group.  However, in practice, re seems to stop well before the end of
the string, and well before the last instance of '>>'.  In other
words, the group doesn't seem to contain everything it should.

I'm manipulating a binary file (and therefore a string with 8-bit
binary characters), so I thought perhaps the `.' was not matching the
NULL character.  So I changed the expression above to
'<<((.|\000)*)>>'.  My understanding is that this should match either
the normal dot regular expression, or a literal zero (NULL) character,
and this pattern would then be matched zero or more times.  However,
the behavior is basically the same.

Anyone have any idea what I should do?  I'm thinking of translating
the whole string to hexadecimal, then converting any numbers less than
or equal to 0x7F back to 7-bit ASCII, but that sounds like it'd be
really slow.  What am I missing?  Is there a canonical way to handle
this?

-----------------------------------------------------
Steven D. Arnold        stevena at nospam.neosynapse.net
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From garth_grimm at hp.com  Thu Sep 13 15:32:00 2001
From: garth_grimm at hp.com (Garth Grimm)
Date: Thu, 13 Sep 2001 12:32:00 -0700
Subject: unicode strings and such
References:  <3BA0CC8E.1050705@hp.com> <9nqmju02eu8@enews2.newsguy.com>
Message-ID: <3BA109B0.2050809@hp.com>

Slick.  Thanks.

Alex Martelli wrote:

> "Garth Grimm"  wrote in message
> news:3BA0CC8E.1050705 at hp.com...
>     ...
> 
>>encodings?  Now that I think of it, I don't recall any file open methods
>>
> that took encoding
> 
> The codecs standard module has that.
> 
> 
> Alex
> 
> 
> 
> 

From db3l at fitlinxx.com  Mon Sep  3 20:21:11 2001
From: db3l at fitlinxx.com (David Bolen)
Date: 03 Sep 2001 20:21:11 -0400
Subject: char** to {'':('',)}
References:  <9mocc301q7f@drn.newsguy.com>
Message-ID: 

Grant Griffin  writes:

> I can't say I use them much, but I _am_ a big fan of the
> "almost-goto" constructs like return, break, and continue.  In
> particular, I like to do early returns to avoid needless nesting.

While I do use them at times, of the various control interruption
constructs, early returns are probably the least preferable for me of
the bunch, mostly because they increase the risk of missing some
needed cleanup - either when initially written or later when
maintained.  They can also complicate the maintenance of code since
there are many exits from a function complicating analysis.

> Coincidentally, I thought I'd seen everything there was to see about
> gotos until just yesterday, when I saw a new form that I had never
> ever seen (or even thought of) before.  It goes to this:
> 
>    bool foo()
>    {
>        bool flag = false;
>        for (;;)
>        {
>            if (x)
>            {
>               flag = true; 
>               break;
>            }
> 
>            do_stuff;
> 
>            if (y)
>            {
>                flag = true;
>                break;
>            }
> 
>            do_more_stuff;
> 
>            break;
>        }
> 
>        return flag;
>    }
> 
> whereas any sensible person would have done:
> 
>    bool foo()
>    {
>        if (x)
>           return true;
> 
>        do_stuff;
> 
>        if (y)
>           return true;
> 
>        do_more_stuff;
> 
>        return false;
>    }
> 
> or maybe even used gotos .  This construct occurred repeatedly
> throughout the code.  The author considered it to be a "feature".

While using the loop construct instead of more straight-forward gotos
is a little strange, I'm not sure it's worse (nor less "sensible")
than the the multi-return format, which to my mind complicates
maintenance down the road by having multiple exit points without a
major benefit.  I'd rather burn the flag variable and know that there
was a consistent exit path that used that variable.

--
-- David
-- 
/-----------------------------------------------------------------------\
 \               David Bolen            \   E-mail: db3l at fitlinxx.com  /
  |             FitLinxx, Inc.            \  Phone: (203) 708-5192    |
 /  860 Canal Street, Stamford, CT  06902   \  Fax: (203) 316-5150     \
\-----------------------------------------------------------------------/

From skip at pobox.com  Mon Sep  3 10:47:29 2001
From: skip at pobox.com (Skip Montanaro)
Date: Mon, 3 Sep 2001 09:47:29 -0500
Subject: typechecks: just say no! (was Re: Determining Types)
In-Reply-To: <3b938f31.2123170@nntp.sprynet.com>
References: 
        <9mvo0u04o8@enews2.newsguy.com>
        <3b938f31.2123170@nntp.sprynet.com>
Message-ID: <15251.38913.163695.524974@localhost.localdomain>

One place that I've actually found typechecking useful is at the boundary of
my XML-RPC server.  If I'm expecting a string input (say, the name of a
band) and someone on the other side inputs "311" to a Perl-based website
which then passes the query to my server, I get an integer that I have to
coerce back to a string.  In my comments I call it a "Perl guard". ;-)

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/

From garry at sage.att.com  Mon Sep 10 15:55:12 2001
From: garry at sage.att.com (Garry Hodgson)
Date: Mon, 10 Sep 2001 19:55:12 GMT
Subject: [Edu-sig] assigning homework
References:  <9ne6ai$fqm$1@news.service.uci.edu>
Message-ID: <3B9D1AA0.5D0C6773@sage.att.com>

Danyel Fisher wrote:
> 
> I've had good experiences with MOSS
> (http://www.cs.berkeley.edu/~aiken/moss.html), although it takes a (gasp!)
> Perl script to submit requests. In general, it seems to do a pretty good job
> of picking out duplicate code. The times I used it, as a TA for a class of
> several hundred, I was able to pull out a few unamiguous cases of
> plagiarism.
> 
> (Cheaters don't seem to be terribly subtle about it).

snicker...i remember one night working at the help desk a few millennia
ago, 
a member of our football team presented me with a listing and asked "if
i
wanted to make this look like i wrote it, what would i have to change?"
he had zero clue what any of of the symbols on the page meant.  it may
as
well have been written in klingon.

i mumbled something unhelpful about different variable names, and he
wandered off, no doubt wondering what a variable was.

-- 
Garry Hodgson                   sometimes we ride on your horses
Senior Hacker                   sometimes we walk alone
Software Innovation Services    sometimes the songs that we hear
AT&T Labs                       are just songs of our own
garry at sage.att.com

From cgaston at moonqzie.com  Fri Sep 14 05:37:41 2001
From: cgaston at moonqzie.com (Carlos Gaston Alvarez)
Date: Fri, 14 Sep 2001 11:37:41 +0200
Subject: Python parsers that parse Java?
Message-ID: <013101c13d00$e69d3000$a500a8c0@moonqzie>

Hi Kevin,

   If you want to do it right you should not execute java source. OK, may be
you can but if they call an api how will you handle it? Also you can insert
parser bugs.
   What you should do is to execute the java program (its bytecodes) in a
java virtual machine.
   You have two options.
    Number one is Jython  www.jython.org which is python in java, it runs in
a jvm and it intercases in a really easy way with java. Take a look and see
if it works for you. If so it is the easiest and best way to do it.
    The second, but less recomendable is to instanciate a jvm from a C
program (interfaced with java). Download the java jdk and you will see some
source that lets you intancitate and call it from a C program.

Chau,

Gaston

----- Original Message -----
From: "Kevin Dahlhausen" 
Newsgroups: comp.lang.python
To: 
Sent: Friday, September 14, 2001 2:36 AM
Subject: Python parsers that parse Java?

> Is there a readily availble parser written in Python that can parse
> java code?  I'm forced to use java for a project, and would like to
> automate some code generation with Python.  I don't have a lot of time
> to devote to this, so something ready to go would be best.
>
> Thanks
> --
> http://mail.python.org/mailman/listinfo/python-list
>

From michael at rcp.co.uk  Fri Sep  7 03:43:26 2001
From: michael at rcp.co.uk (Michael Abbott)
Date: Fri, 7 Sep 2001 07:43:26 +0000 (UTC)
Subject: Recursion and Variable Scope
References: 
Message-ID: 

mudpyr8 at yahoo.com (mudpyr8) wrote in 
news:d9f7d05e.0109061911.6bdcda3f at posting.google.com:

> I'm writing a simple function. It is recursive. Here's the code:
> 
> ##########################
> def generate(sides, dice, roll):
>      if dice > 0:
>           for x in range(sides):
>                roll.append(x+1)
>                generate(sides, dice - 1, roll)
>                roll.pop()
>      else:
>           print roll
> ##########################
> 
> When calling it: generate(4, 2, [])
> will generate output of 16 pairs of values, 1-4 each. However, I
> cannot get that result stored in an object; I can only print it.
> 
> The last line is the tricky part. Where it says   # print roll #   I
> want it to do something like:   # rolls.append(roll) #  .
> Unfortunately, creating a variable   # rolls = [] #   outside of the
> function definition, and even stating   # global rolls #   on the
> first line of the block doesn't seem to matter.
> 
> I've tried to wrap my mind around this but am stuck. I need to perform
> further manipulation on the results, but have no object with which to
> do so. I know I could write to a file (maybe, if the file handle works
> within the recursion) and then read it but that seems like a waste of
> time.
> 
> I hope I'm just missing something obvious. Please, any help would be
> appreciated.
> 

It would have helped if you'd been a bit more explicit about the problem 
you're seeing, but one answer is quite straightforward.

If you replace "print roll" with

    	global rolls
    	rolls.append(roll)

then the result you get is a list of empty lists, not quite what you had in 
mind, and at first somewhat unexpected.
    	The problem is that when you append roll to the accummulating result 
list, it is still mutable, and you carry on working with roll in subsequent 
processing.  You need, therefore, to put a *copy* of roll on the list.  The 
following works:

    	global rolls
    	rolls.append(roll[:])

However, using a global like this isn't a good idea.  You should look 
instead to get generate() to return the list you're after.  Also note that 
this problem is nothing to do with variable scope: it is simply a 
consequence of the fact that roll is the same (mutable) list throughout.

From loewis at informatik.hu-berlin.de  Fri Sep 14 08:36:27 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 14 Sep 2001 14:36:27 +0200
Subject: no math module
References: <3BA1F38E.ECD86D90@ncsa.uiuc.edu>
Message-ID: 

Randy Heiland  writes:

> Can someone point me in the right direction?

As the starting point, you should find out whether a math.so has been
build by setup.py; it should live in build/lib. of the source
tree. If yes, you'll have to find out whether it was properly
installed, looks like a shared library (file(1), nm(1)), and lives in
a location that is in sys.path.

If not, re-run the build process to find out whether there are any
errors reported when attempting to build math.so.

Regards,
Martin

From mmhamze at pleiades.net  Fri Sep  7 10:07:08 2001
From: mmhamze at pleiades.net (Maan M. Hamze)
Date: Fri, 7 Sep 2001 09:07:08 -0500
Subject: Creating Excel files on Linux
References: <3B97A39C.6A5234D7@olen.to>   
Message-ID: 

Cool it down guys.  You take things so personal.  When I say that the world
speaks the XLS language I mean that is what your average Joe Blow and Jane
Doe understand behind their desks in their offices.  I did not not mean it
as a computer programming language.
However, on another front VBA as an overarching paradigm remains quite an
achievement that actually works in windows.
Maan

"Oleg Broytmann"  wrote in message
news:mailman.999869469.17318.python-list at python.org...
> On Fri, Sep 07, 2001 at 08:04:47AM -0500, Maan M. Hamze wrote:
> > But the question is:  Can Staroffice create XLS files?  If not, then it
is a
> > major waste of time to create spreadsheets using Staroffice.  It is a
world
> > that speaks the XLS language.
>
>    If it is true, why are wasting your time with Python? It is a world
that
> speaks Java, Perl, PHP and C++.
>
>    Thanks heavens you are completely wrong in this aspect. In my world
> there is enough room for many different langauges and dialects. I pity you
> if you live in such a narrow world. If you have any chance - go to a world
> that allows more freedom! The world of Free Software!!!
>
> Oleg.
> ----
>      Oleg Broytmann            http://phd.pp.ru/            phd at phd.pp.ru
>            Programmers don't die, they just GOSUB without RETURN.
>

From ignacio at openservices.net  Tue Sep 11 01:55:28 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Tue, 11 Sep 2001 01:55:28 -0400 (EDT)
Subject: form - mail - smtp using Python 1.5.
In-Reply-To: 
Message-ID: 

On Tue, 11 Sep 2001, Jerry Cashman wrote:

> All the example code I've found appears to call a module called smtplib.py
> which doesn't appear to exist in Python 1.5

Then your installation of Python is probably broken. Python 1.5.2 has it for
certain.

-- 
Ignacio Vazquez-Abrams  

From vdkamp at inter.nl.net  Wed Sep  5 14:59:39 2001
From: vdkamp at inter.nl.net (Peter van der Kamp)
Date: 05 Sep 2001 18:59:39 GMT
Subject: Size of tuples
Message-ID: 

Hello,

Does anyone anyone know what the maximum size of
a tuple can be? Examples in documentation only contains
a small amount of data, but I like to know if they can contain
e.g. >100000 integers. Furthermore I would like to know
the consequences for performance. Does the 'x in tuple'
statement perform much worse with the amounts of data
I have in mind?

Thanks.

Peter van der Kamp

From dsh8290 at rit.edu  Sat Sep 15 20:32:41 2001
From: dsh8290 at rit.edu (dman)
Date: Sat, 15 Sep 2001 20:32:41 -0400
Subject: [Tutor] SMTPLIB module - how to add subject ?
In-Reply-To: <5FEF7E62AE5@kserver.org>
References: <3BA3D9FE.30092.76C3D5@localhost> <5FEF7E62AE5@kserver.org>
Message-ID: <20010915203241.B2641@hudson>

On Sat, Sep 15, 2001 at 02:05:40PM -0700, Sheila King wrote:
| On Sat, 15 Sep 2001 22:45:18 +0200, "A"   wrote
| about [Tutor] SMTPLIB module - how to add subject ?:
| 
| :Hi,
| :I tried 
| :11.11.2 SMTP Example from Python docs.
| :Does anyone know how I can add subject to an email send by this example?
| :Thank you very much for help
| :Ladislav
| 
| I've pasted the example below. Actually, I really dislike this example.
| They are using
| "\r\n"
| as a character for newlines. Whose idea was that???
| It should be just
| "\n"

Well, in RFC2821 the SMTP protocol states that \r\n is used as the
line delimiter.  (RFC821 was the original SMTP definition but has been
superceded by RFC2821)

However, the Subject: of a message is part of the message itself which
is defined by RFC822, but I haven't read that RFC.

| I still don't like the "\r\n" in this example. Bad. :(

See above -- the RFC actually states that being lenient and allowing
\n as a line separator (mainly for Unix servers) is highly
un-recommended (if I can make up that word).

-D

From logiplexsoftware at earthlink.net  Mon Sep 10 16:09:36 2001
From: logiplexsoftware at earthlink.net (Cliff Wells)
Date: Mon, 10 Sep 2001 13:09:36 -0700
Subject: newbie: cannot import name error
In-Reply-To: <3B9D11B9.D665D36A@engcorp.com>
References:   <3B9D11B9.D665D36A@engcorp.com>
Message-ID: <01091013093602.10843@logiplex1.logiplex.net>

On Monday 10 September 2001 12:17, Peter Hansen wrote:
> David Bolen wrote:

> Meanwhile, is it really the case that "extension" refers
> exclusively to code not written in Python?  If so, please
> refer me to where the official definition has been made
> so I can set my mind at ease.

Semantically, you may be correct.  However, for the sake of clarity, I think 
most people think of extensions as being written in C (probably because the 
process of integrating with C is referred to as "Extending and Embedding" in 
the documentation).

-- 
Cliff Wells
Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 x308
(800) 735-0555 x308

From donn at u.washington.edu  Tue Sep  4 13:04:59 2001
From: donn at u.washington.edu (Donn Cave)
Date: 4 Sep 2001 17:04:59 GMT
Subject: Conditional operator in Python?
References:  <9n1vir$chl$1@glue.ucr.edu>
Message-ID: <9n31jr$16j0$1@nntp6.u.washington.edu>

Quoth thp at cs.ucr.edu:
...
| Okay, factorial is a somewhat simplistic example.  Consider the
| following function, which counts the k-way partitions of n:
|
|   p = lambda k, n : (
|       ( k < 1  or k > n  ) and [0] or 
|       ( n == 1 or n == k ) and [1] or 
|       [p(k-1,n-1)+p(k,n-k)] 
|     )[0]
|
| Using, say, ?: notation this would be written:
|
|   p = lambda k, n : 
|     k < 1  or k > n  ? 0 :
|     n == 1 or n == k ? 1 :
|     p( k-1, n-1 ) + p (k, n-k )
|
| which seems much more concise and readable.

I am working intermittently on a modification to some code that was
written in C by someone with a compulsion for syntax like that.
I spent many hours on a trivial rewrite of a module of his like
the one I want to write, just so I could read it.

Though the second example may be more concise and readable than
the first, it's much less readable than a normal procedural solution.
The first on the other hand has the advantage that only the most
obtuse author could argue that it's readable at all, while the
second sort of legitimizes this kind of obfuscation in Python.

	Donn Cave, donn at u.washington.edu

From loewis at informatik.hu-berlin.de  Sun Sep 30 18:14:37 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 01 Oct 2001 00:14:37 +0200
Subject: How do Java interfaces translate to Python?
References: 
Message-ID: 

Gordon Tyler  writes:

> My question is this: Java being my primary language, I'm very used to
> using interfaces and I was wondering if there was an equivalent construct
> or idiom in Python? How does one do in Python what one would do with
> interfaces in Java?

What exactly is it that you do with interfaces in Java?

Regards,
Martin

From sholden at holdenweb.com  Thu Sep 27 14:01:48 2001
From: sholden at holdenweb.com (Steve Holden)
Date: Thu, 27 Sep 2001 14:01:48 -0400
Subject: Is Python fit for multi-tiEred apps?
References: <9o7lvv$170$01$1@news.t-online.com><9oup0t$7tf$00$1@news.t-online.com> 
Message-ID: 

In distributed computing applications, the original architecture was
client/server. Typically the client was the desktop machine, which handled
the GUI and usually most of the process logic and some of the application
logic. The client would communicate across the network to a server, which
would handle the remainder of the application logic and all the data
management tasks.

Conceptually, applications therefore have four components:

Presentation (user interface) logic
Process logic
Application logic ("business rules")
Data Management

Nowadays the logic can be distributed between more than two machines, so you
might see the GUI running on the desktop along with the process logic, the
business rules being enforced by a "middle tier" server, and the data
management handled by an enterprise RDBMS. This is the "classic" three-tier
structure.

Another three-tier example is when a browser (presentation layer) is used to
drive a web server (process logic, application logic) which transacts
against an RDBMS (data management).

The advantage of these architectures is that you can centralise or
distribute the business rules as you see fit, but that you don't have to do
what traditional C/S applications did, which was to include business rule
handling on the desktop. This became a maintenance nightmare for large
organizations with hundreds or thousands of desktops: when the business
rules changed, new client software had to be rolled out to all the desktops.

regards
 Steve
--
http://www.holdenweb.com/

"Fran?ois Pinard"  wrote in message
news:mailman.1001606015.16060.python-list at python.org...
> [Eike Kock]
>
> > [...] scaleable enterprise systems (multi-tiered [...]
>
> Hi.  Would someone be kind enough for presenting to me what `tiered'
means?
> I never read that word, before the recent threads about it.  What is it?
>
> --
> Fran?ois Pinard   http://www.iro.umontreal.ca/~pinard
>

From jknapka at earthlink.net  Wed Sep  5 12:13:29 2001
From: jknapka at earthlink.net (Joseph Andrew Knapka)
Date: Wed, 05 Sep 2001 16:13:29 GMT
Subject: deiconify is just plain f*ucked in windows
References: 
Message-ID: <3B95FA1B.FE50AF5C@earthlink.net>

gcash wrote:

> I'd write it in tcl if I had an XML library for it.

How about

Cheers,

-- 
# Joe Knapka
# "You know how many remote castles there are along the
#  gorges? You can't MOVE for remote castles!" - Lu Tze re. Uberwald
# Linux MM docs:
http://home.earthlink.net/~jknapka/linux-mm/vmoutline.html

From kseehof at neuralintegrator.com  Thu Sep 27 19:35:00 2001
From: kseehof at neuralintegrator.com (Ken Seehof)
Date: Thu, 27 Sep 2001 16:35:00 -0700
Subject: WeakValueDictionary
References:  <3BB11793.7040201@ActiveState.com>
Message-ID: <004c01c147ad$08c30f40$239ab23f@kens>

> Ken Seehof wrote:
> 
> >  >>> sys.version
> > '2.1.1 (#20, Jul 20 2001, 01:19:29) [MSC 32 bit (Intel)]'
> >  >>> import weakref
> >  >>> d = weakref.WeakValueDictionary()
> >  >>> d['z']
> > Traceback (most recent call last):
> >   File "", line 1, in ?
> >   File "C:\PYTHON21\lib\weakref.py", line 35, in __getitem__
> >     o = self.data.get(key)()
> > TypeError: object of type 'None' is not callable
> > 
> > Shouldn't this be raising KeyError instead of TypeError?
> 
> Probably :)
> 
> While we are at it, I would like to see the ability to have a weak-ref 
> to None - this would allow me to remove special casing for None in the 
> places I have used weakrefs to date.
> 
> But-that-is-a-different-problem ly,
> 
> Mark.

Well here's how I got around the weak None thing:

def NoneRef():
    return None

Then you can say x=NoneRef and x will act like a weak-ref to None.
(yeah, I know return None is the same as pass, but I like being explicit)

Whaddya-think-should-I-patent-it-ly yrs,

- Ken

From lud at sogetek.fr  Wed Sep  5 10:04:26 2001
From: lud at sogetek.fr (lud)
Date: Wed, 5 Sep 2001 16:04:26 +0200
Subject: a simple question for writtting module
References:  <9n59fk01upf@enews1.newsguy.com>
Message-ID: 

i must do it,
but don't be afraid, i writting this
module for vxWorks and for a personnal use !
so i think that you probably never use it !!

Thanks a lot for your quick answer !!!

Ludo

"Alex Martelli"  a ?crit dans le message news:
9n59fk01upf at enews1.newsguy.com...
> "lud"  wrote in message
> news:Hhpl7.530$mg1.11523 at tengri.easynet.fr...
> > Hi !!
> >
> > my problem :
> >
> > first i write in python :
> >         import mymodule
> >         data="is a test"
> >         mymodule.show()
> >
> > ###################
> > now in c :
> > static PyObject *
> > mymodule_show(PyObject * self, PyObject *args)
> > {
> > /*bla bla bla ....*/
> > }
> > so i want get the value of data without transmit her in the call of the
> > function show
> >
> > any idea ?
>
> Yes, several.
>
> The first and main one: don't do it -- it's silly.  It's
> counter-productive.  It's unPythonic.  It's the style of
> programming that gives programming a bad name.
>
> The second one: if you MUST do it at any cost, look into
> sys._getframe, the frame-objects type it returns, and
> how from a frame-object you can get at your caller's
> local and global variables -- this will let you do this
> silliness pretty easily in Python, and the extra mile to
> do it from C is really only 800 meters, as it's so easy
> for C code to do the equivalent of "import sys", call
> the _getframe function of module sys, and so on.
>
> At least, when you're done, you'll have learned a lot
> about some of Python's internals and the use of them
> from C extension code -- also, this will give you the
> time to reflect on whether you really truly want to
> do this at all, and hopefully reconsider:-).
>
>
> Alex
>
>
>

From alberto at mindspring.com  Sun Sep  2 20:49:00 2001
From: alberto at mindspring.com (Al Gonzalez)
Date: Sun, 2 Sep 2001 20:49:00 -0400
Subject: calling __init__ more than once?
References:  <9muijb$47a46$1@ID-11957.news.dfncis.de>
Message-ID: <9muk1q01o21@enews3.newsguy.com>

There doesn't seem to be a reason why you can't.

I prefer to move things into a method that can be called
from multiple places including __init__.  This keeps me
from accidentally doing things again that I only want to
happen when the class is created - such as gathering
resources..

class myParser:
    def __init__(self):
        self._prepareEnvironment()
    def parse(self, fileName):
        self._prepareEnvironment()
        # do stuff with fileName
    def _prepareEnvironment(self):
        # utility method to clear up variables
        self._fileName = None
        self._buffer = []

"Emile van Sebille"  wrote in message
news:9muijb$47a46$1 at ID-11957.news.dfncis.de...
> One thing you could try is to restructure slightly, passing the filename
on
> initialization:
>
> stuff1 = myParser(fileName1)
> stuff1.parse()
> stuff2 = myParser(fileName2)
> stuff2.parse()
>
> HTH,
>
> --
>
> Emile van Sebille
> emile at fenx.com
>
> ---------
> "Roy Smith"  wrote in message
> news:roy-5FC394.18555502092001 at news1.panix.com...
> > I've got a file parsing class which in which I call a single parser
object
> > repeatedly to parse additional files.  Something like:
> >
> >    p = myParser()
> >    stuff1 = p.parse (fileName1)
> >    stuff2 = p.parse (fileName2)
> >
> > Is there any reason why my parse method couldn't call __init__() to
reset
> > things back to the start state?  It feels kind of creepy, but I don't
see
> > any reason why it should be a problem.  Is there something I'm missing
> > here, or is it really OK to call __init__() again?
>

From ignacio at openservices.net  Tue Sep  4 11:20:38 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Tue, 4 Sep 2001 11:20:38 -0400 (EDT)
Subject: Hi, there
In-Reply-To: <3B94EFD3.3360D44B@zumnet.com.br>
Message-ID: 

On Tue, 4 Sep 2001, Rafael Mentz Aquino wrote:

> Hi, everybody! I'm new on this list and a begginer with Python,
> with special interests in Tkinter.
>
> I hope I can help and get help from here ;-)
>
> Let me start with a little problem...?
>
> I'm making an experience, but I can't  put the result of an os.system
> to a variable.... just the exit status....
>
> How can I read the stdout to solve that..?
>
> Thanks already!!!!
>
> Rafael Mentz Aquino
> Porto Alegre - Brazil

Look at os.popen().

-- 
Ignacio Vazquez-Abrams  

From ignacio at openservices.net  Sun Sep 16 23:37:39 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Sun, 16 Sep 2001 23:37:39 -0400 (EDT)
Subject: SWIG: ImportError: dynamic module does not define init function
In-Reply-To: <3BA56CB6.5786D4C2@northwestern.edu>
Message-ID: 

On Sun, 16 Sep 2001, Louis Luangkesorn wrote:

> I'm trying to run the example from the SWIG User's Guide (V 1.1 June 23,
> 1997)  When I try to load the example I get the following:
>
> PythonWin 2.1 (#15, Apr 19 2001, 10:28:27) [MSC 32 bit (Intel)] on
> win32.
> Portions Copyright 1994-2001 Mark Hammond (MarkH at ActiveState.com) - see
> 'Help/About PythonWin' for further copyright information.
> >>> import sys
> >>> sys.path.append('c:\lluang\gmcode\cnumint\debug')
> >>> import cnumint
> Traceback (most recent call last):
>   File "", line 1, in ?
> ImportError: dynamic module does not define init function (initcnumint)
> >>>
>
> I've noticed on various mailing lists several people have asked this
> same question, but I have not seen anyone respond to this.  Is there
> something I'm missing?  Thanks.

It's really quite simple. Your C code is missing the init()
function which is responsible for actually setting up the module for use. Take
a look at the modules that come with Python for examples on how it should be
implemented.

-- 
Ignacio Vazquez-Abrams  

From Gareth.McCaughan at pobox.com  Tue Sep 11 18:56:06 2001
From: Gareth.McCaughan at pobox.com (Gareth McCaughan)
Date: Tue, 11 Sep 2001 23:56:06 +0100
Subject: Proposed PEP for a Conditional Expression
References:  
Message-ID: 

Terry Reedy wrote:

[Christian Tanzer:]
> > Conditional expressions provide some nice benefits totally
> > unrelated to lambdas.
> > One example: with a trivial class, one can put expressions into
> > format directives, like
> >   "Found %(number)d error%(if number == 1 : '' else : 's')s" % trivial
> 
> Python does not evaluate expressions inside strings and I do not
> expect it ever will.

class Trivial:
  def __getitem__(self, key):
    return eval(key, globals(), locals())

"foo %(1+2+3)s bar" % Trivial()    ===> "foo 6 bar"

Giving it access to the caller's local variables
isn't quite so easy.

-- 
Gareth McCaughan  Gareth.McCaughan at pobox.com
.sig under construc

From phr-n2001 at nightsong.com  Tue Sep 25 12:08:10 2001
From: phr-n2001 at nightsong.com (Paul Rubin)
Date: 25 Sep 2001 09:08:10 -0700
Subject: Proposal: add vector arithmetic to array module
References: <7x3d5d2ca7.fsf_-_@ruckus.brouhaha.com> <3BAFA038.FB17C2D7@home.net>
Message-ID: <7xzo7jqmmt.fsf@ruckus.brouhaha.com>

Chris Barker  writes:
> > Please suppress the urge to reply "use NumPy".
> 
> I'm sorry, but I can't suppress it. NumPy is so clearly what you want
> here.

No, NumPy is NOT what I want:

1) doesn't come with Python
2) not maintained by Python maintainers
3) Only handles floating point data, not integer.  For example
   it doesn't provide vector boolean operations (I just remembered this--
   so earlier when I said I'd use it if it was part of standard Python,
   I was in error).

> > Numpy is a big package
> 
> It's not that big.

If it takes more than 1 minute to download over a modem, it's "big".
It imposes extra hassle and delay on a user who wants to run an app that
requires it.

Anyway, NumPy is ridiculous overkill if all I want to be able to do
is quickly xor two strings together, something like
  a = array.array('b', str1)
  array.xor(a, a, array.array('b', str2))

> > that's not part of standard Python
> 
> It should be.

That would make it mostly ok for what I'm doing, modulo the xor issue.

> with a lot of PDF documentation
> 
> Since when is lots of good documentation a BAD thing???????

Documentation good.  PDF documentation bad.  I see there's an HTML
version of the docs on pfdubois' site (it's not in the Sourceforge
site) but it's not clear where the doc sources are.  Any idea?

> > That makes it
> > a lot harder to distribute applications to non-technical users.  It's
> > bad enough that they already have to install Python to run Python apps.
> 
> Sort of. As you say, Python has to be installed, and the correct
> version, and all that. Given that, many folks have chosen to use Py2exe
> or McMillan's Istaller for distributing Python apps. with these tools,
> youcan just give them NumPy along with the rest.

Py2exe is a windows-only thing.  What's McMillan's installer?  Anyway
if there's a way I can easily include NumPy with an application, then
maybe it's ok.  But it's bizarre to have to make multiple OS-specific
distributions of an app written entirely in Python and that uses no
complicated system calls.

I think what's really needed is something like JAR files, for packaging
Python apps.  Maybe they could be called CAN files (snakes in a can) .
There was some discussion of this earlier so maybe something will happen.

> For that matter, there is something of a push to create a "batteries
> and accessories included" approach to installing Python. ActiveState
> has made a start of this with their distribution and pyppm. I have
> started a project alnong these lines as well, but havn't gotten far
> because no one else seems to think it's worth it. I still, do, but I
> lost a lot of motivation.

I thought "batteries included" was already supposed to be part of Python's
philosophy, not something that there needed to be a push to create.

> Which is easier:
> 
> Adding a bunch of functionality to a standard module.
>
> Making a widely used, robust, and powerfull module standard.

Generally, adding functionality to an existing module is easier.
Especially when, as in the particular functionality we're discussing,
it's not really "a bunch".  I don't know if that's the answer you
wanted .

> Personally, I think we should go beyond making NumPy a standard module,
> and make NumPy Arrays a built-in type.

That sounds reasonable to me.

From aleax at aleax.it  Fri Sep  7 10:02:50 2001
From: aleax at aleax.it (Alex Martelli)
Date: Fri, 7 Sep 2001 16:02:50 +0200
Subject: newbie: cannot import name error
References: 
Message-ID: <9nak2a0t9n@enews1.newsguy.com>

"rjberman at NOSPAMrodessaNOSPAM.com"  wrote in message
news:rb999869338 at rodessa.com...
> I am brand new to Python, but have been writing Perl scripts for
> the last 10 yrs. or so. I want to see how Python compares to Perl
> and if it lives up to its hype.
>
> Anyway, I installed Python version "1.6a2 (#1, Jun  1 2000, 13:24:17)
> [GCC 2.96 20000306 (experimental)] on sunos5" on Sparc Solaris 8. It

Note that the version code indicates an *alpha* version (albeit
alpha-2), as well as a pretty old version (1.6) which was NOT
long-lived (it was a "contractual obligation" version the Python
team had to do before changing employers) *and* an experimental
C compiler too -- what an explosive mix!

> It seems like the module distutils.core is found, just not the
> name "Extension".

Maybe the distutils didn't yet have Extension back in the
time of 1.6 alpha 2.  Wouldn't surprise me.

> Can someone help me? I can't believe that on my second encounter
> with Python I've already been stumped! This is not a good first
> impression. Any help would be appreciated or even pointers to help!

Do you generally try to gain a "first impression" of any
software by installing an 18-months-old alpha release?-)
I wouldn't be surprised to "be stumped" if I did that:).

I would suggest you start by installing a solid, current,
stable release, such as:
http://aspn.activestate.com/ASPN/Downloads/ActivePython/Download?OS=Solaris&
version=2.1.1&build=212&download=/ActivePython/solaris/2.1/ActivePython-2.1.
1-212.tar.gz

Apparently, this ActivePython 2.1.1 release supports Solaris 2.6 --
I don't know if that may give problems with 2.8, as it's been a
long time since I did Solaris.  If the 2.8-vs-2.6 IS a problem,
then build and install from the source release:
http://prdownloads.sourceforge.net/python/Python-2.1.1.tgz
(I would also suggest using a recent, stable C compiler,
such as gcc 3.0.1, of course -- http://gcc.gnu.org/gcc-3.0/ --
but I guess the key thing is using the same C compiler to
build Python as to build extensions, just in case any
incompatibility in generated binaries or libraries used
may have appeared between C compilers and/or versions).

Alex

From richard at bizarsoftware.com.au  Mon Sep 10 20:25:40 2001
From: richard at bizarsoftware.com.au (Richard Jones)
Date: Tue, 11 Sep 2001 10:25:40 +1000
Subject: idea: Robocode for Python - (redux :)
In-Reply-To: 
References:  
Message-ID: <0109111025400Q.01597@ike>

Anyone remember the python robots effort we had a few years ago? We had a 
mailing list and all called "bots-list" - I have no archives, and amk's 
archive is no longer either...

I seem to recall that we all got busy with our Real Jobs at the time and 
never got back to it...

Let's see...

I think the most progress that came out of it was Greg Stein's code:
   http://www.pythonpros.com/gstein/war/

Greg also has a bunch of links for bot-stuff. It's probably really old (was 
updated in October, year unknown :) Haven't tested any of the links:
   http://www.pythonpros.com/gstein/bots.html

John Eikenberry produced some code too (though his website has vanished):
   ftp://ftp.coe.uga.edu/users/jae/PyBots/

Toby Sargeant and I went several steps in another direction - we believed 
that "processor-level" control was the only way to go to have a level playing 
field, and we'd actually designed the basis of a new language with all sorts 
of bot-specific stuff in it like event handling with inheritance and other 
fun :)

    Richard

From BrianQ at ActiveState.com  Wed Sep 12 18:36:16 2001
From: BrianQ at ActiveState.com (Brian Quinlan)
Date: Wed, 12 Sep 2001 15:36:16 -0700
Subject: Reading variable length records...
In-Reply-To: <6957F6A694B49A4096F7CFD0D900042F27DBC2@admin56.narex.com>
Message-ID: <002701c13bdb$562fbbd0$b503a8c0@activestate.ca>

> I'm trying to read records from a 2 GB datafile, but my brain has
> stopped working, so I was wondering if someone has allready 
> solved this problem. The records are variable length and are 
> separated by a five character delimiter. I was trying to use 
> file.read(n) with a blocksize of ~1Mb, but got a serious 
> brainfart when trying to think of how to handle the case where 
> only part of the delimiter was read in the current block.

Here is some pseudo-code to get you started:

data = ''
records = []

while 1:    
    readData = datafile.read(size)
    if not readData:
        break

    data += readData 
    partialRecords = data.split('12345')
    records += partialRecords[:-1] # Last record is incomplete
    data = records[-1]

if data:
	# Hmmm, there is still data left over, probably bad

The basic idea is that you use split to collect as many records as
possible and just keep the left-over partial record for the next
round. Let me know if you need clarification.

Cheers,
Brian
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From ignacio at openservices.net  Fri Sep 21 03:47:30 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Fri, 21 Sep 2001 03:47:30 -0400 (EDT)
Subject: "shell-commands" and python!
In-Reply-To: <9oeqks$8t0$1@zingo.tninet.se>
Message-ID: 

On Fri, 21 Sep 2001, Mike S wrote:

> how do I execute "shellcommands" in python???
> do I need to use the os module and the system command?

Yes, or you could use popen*().

> Is there any simplier way to do it??

What, os.system('mycmd') isn't simple enough? Yeesh! Programmers these days...

-- 
Ignacio Vazquez-Abrams  

From dale at riverhall.NOSPAMco.uk  Mon Sep 17 15:30:40 2001
From: dale at riverhall.NOSPAMco.uk (Dale Strickland-Clark)
Date: Mon, 17 Sep 2001 20:30:40 +0100
Subject: How to get a directory size with win32 api ?
References: <85e27928.0109170448.693d122b@posting.google.com>
Message-ID: 

francois-regis.chalaoux at sanofi-synthelabo.com (copter24) wrote:

>Hi,
>
>How to get a directory size with win32 api ?
>Any code exemple ?
>
>FR

If you mean in terms of total kbytes occuplied, I don't think you can.

You can, however, use the FileSystemObject COM object which is part of
VBScript/JScript but I think can be used anywhere COM is accessible.

>>> from win32com.client import Dispatch
>>> fso = Dispatch("Scripting.FileSystemObject")
>>> fldr = fso.GetFolder("C:\\WINNT")
>>> fldr.Size
892129383
>>> 

If you mean in terms of number of files, os.listdir() will probably do
the job.
--
Dale Strickland-Clark
Riverhall Systems Ltd

From russomf at hotmail.com  Thu Sep 13 12:20:47 2001
From: russomf at hotmail.com (Mark)
Date: 13 Sep 2001 09:20:47 -0700
Subject: Commercial Web Hosting w/ Python CGI Scripts?
Message-ID: 

Does anyone know of a commercial web hosting firm that supports CGI
scripting using Python?  I'd be interested in any flavor, such as
mod-python, Zope, etc.

Thanks.

From loewis at informatik.hu-berlin.de  Tue Sep 25 08:46:31 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 25 Sep 2001 14:46:31 +0200
Subject: dismantling code objects
References: <998474b8.0109240713.6070692e@posting.google.com>
Message-ID: 

dean.hall at computer.org (Dean Hall) writes:

> I'd appreciate any feedback on the doc (I consider it a rough draft
> and won't be offended by constructive criticism).

I find your text well-written, and I'd encourage you to keep it
up-to-date (e.g. Python 2.2 will add a few byte codes).

I think the type setting could use some improvements, e.g. the figure
numbers are never printed, and the tables with empty fields look ugly
(e.g. opcodes 93,94).

I'd spend a few more words on marshal, so that the reader atleast gets
an idea of what it does - you may leave out the information of how
exactly it does that(*).

Regards,
Martin

(*) Of course, there would be a value in elaborating the format of
marshal (and thus .pyc files) as well - I believe it would be the
first documentation of this kind.

From skip at pobox.com  Thu Sep 27 12:42:22 2001
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 27 Sep 2001 11:42:22 -0500
Subject: Is xmlrpclib slow?
In-Reply-To: <20010927154054.A2999@aeka.lysator.liu.se>
References: <9ov48m$eao$1@tyfon.itea.ntnu.no>
        <20010927154054.A2999@aeka.lysator.liu.se>
Message-ID: <15283.22254.460275.660829@beluga.mojam.com>

    Kalle> [Magnus Lie Hetland about xmlrpclib]
    >> Is it just the machine I'm using that's really slow, or is the
    >> xmlrpclib module a big bottleneck here?

    Kalle> Skip Montanaro about performance problems with xmlrpclib:
    Kalle> http://groups.google.com/groups?threadm=mailman.1001257584.1441.python-list%40python.org&rnum=1

I'm still working on that problem.  I've stabilized everything I can so
far.  My next step will be to try upgrading kernels on the slower machine.

Magnus, your problem may just be that you are using a pure Python XML
parser.  I use Fredrik Lundh's sgmlop parser which xmlrpclib will use
automatically if it's available.  I suspect there are other ways to speed up
XML parsing as well.

The other thing to note is that xmlrpclib 1.0b3 (what is delivered with
2.1.1 I think) seems to be much slower than xmlrpclib 0.9.8.  If I modify
sys.path to force import of one or the other, the dump speed changes
markedly:

    % python testxmlrpc.py
    testing with xmlrpclib 0.9.8
    using FastParser
    410 dumps per second
    106 loads per second
    % PYTHONPATH=/home/skip/misc/python/python2 python testxmlrpc.py
    testing with xmlrpclib 1.0b3
    using SgmlopParser
    229 dumps per second
    94 loads per second

SgmlopParser under 1.0b3 is the same as FastParser under 0.9.8.  There's
another parser available from Pythonware for 1.0b3 that is now called
FastParser.  Presumably it's faster or more robust than the SgmlopParser.

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/

From skip at pobox.com  Sat Sep 29 00:57:22 2001
From: skip at pobox.com (Skip Montanaro)
Date: Fri, 28 Sep 2001 23:57:22 -0500
Subject: Off-topic: hiding your email address - don't bother...
Message-ID: <15285.21682.353195.729661@beluga.mojam.com>

(My apologies for the off-topic post.  Python-list at python.org is the only
large mailing list/newsgroup I read with any regularity, so this subject is
only germane to me in this context.)

More and more people are resorting to various schemes to try and hide their
email addresses from email address harvesters.  It's frustrating to me to
get mail bounces when I reply to posts and forget to un-doctor your email
address.  I think it's a fruitless exercise for a few reasons:

    * If I reply-to-all to a message of yours I will get an address like
      skipNO at SPAMmojam.com in the To: or CC: headers.  If I notice it and
      remove "NO" and "SPAM", I've just screwed you, because your email
      address is now going to show up in mailing list archives or Usenet
      headers.  If I don't notice, I get a bounce.  No great loss perhaps,
      though I'm a bit frustrated because my response to perhaps your
      request won't reach you, and you might miss the response to your
      message when skimming c.l.py (or have it expire when you're out of
      town on a business trip).  What are the chances that I will realize I
      should move your email address to the BCC field?  Slim, at best.  If I
      remember to do all the right things, what about Alex or Guido, one of
      the Tims or one of the bots?

    * Your email address probably appears in plenty of other places
      accessible to the harvesters, including: your personal or corporate
      websites, friends' or associates' websites, your soccer club website,
      the archives of this and other mailing lists or newsgroups (none of
      the hypermail/pipermail/etc archives use particularly complex schemes
      to hide addresses and once upon a time you posted messages *without*
      doctoring your email address), SourceForge, or source code you wrote
      that happens to be available on the net.

    * Other people have probably given it out.  That might be your dimwitted
      ISP who thinks that filthy lucre from a direct marketing company is
      more valuable than your good will, or the guy in the next cubicle who
      just CC'd you on a post to alt.binaries.britney-spears.

Try though you might, you probably still get lots of spam.  They find you,
no matter what.  Case in point.  I switched ISPs from MediaOne Express to
AT&T @Home just a couple weeks ago (because the latter bought the former).
I had to select a user id and I wound up with an email address quite a bit
unlike anything else I had ever had before.  I didn't care, because I didn't
intend to ever use it.  *I* certainly never publicized it.  Lo and behold,
during a service call a few days ago the tech said I should check my @Home
email once in awhile because they use it to communicate with their
customers.  I checked and found a "welcome to @Home" message and two spams.

I bet you know the conclusion of this missive: Don't bother trying to
protect your email address.  Resistance is futile.  If you want to filter
out spam, find a service you like that filters email (like SpamCop or your
ISP), learn how to use procmail, or learn to write sendmail milters in
Python or get Jason Mastaler's TMDA system that works with QMail (there - I
snuck in *two* Python code references into my message so it's not
off-topic!).  In short, do something that stands a real chance of helping.
Doctoring up your email address isn't going to cut it.  You're just sticking
your head in the sand...

NsOk-iSpP at ApMo-bLoYx .Yc'oRmS,

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/

From brian at sweetapp.com  Sat Sep 15 15:51:20 2001
From: brian at sweetapp.com (Brian Quinlan)
Date: Sat, 15 Sep 2001 12:51:20 -0700
Subject: Python is better than free (was Re: GNU wars again)
In-Reply-To: <3BBF2751.3010309@sneakemail.com>
Message-ID: <005201c13e1f$cb1824f0$445d4540@Dell2>

>
and-if-it's-good-enough-for-Moses-it's-good-enough-for-Tim-Peters-
-

Bite your tongue! What has Moses done for me lately?

From loewis at informatik.hu-berlin.de  Thu Sep 27 10:28:17 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 27 Sep 2001 16:28:17 +0200
Subject: Does there exist a Python-to-Perl translator ?
References: <3BB2D226.3C260A2C@Spam.Please>
Message-ID: 

Weet Vanniks  writes:

> This would help me produce Perl code after developing it in Python.

There are the beginning of a Python-to-Parrot (aka Perl 6?) compiler.
See the recent posting of Andrew for details:

http://mail.python.org/pipermail/python-dev/2001-September/017617.html

Regards,
Martin

From sheila at spamcop.net  Mon Sep 17 23:43:16 2001
From: sheila at spamcop.net (Sheila King)
Date: Tue, 18 Sep 2001 03:43:16 GMT
Subject: Converting Strings to UPPERCASE ?
References: <3ba6bd0e@news.iprimus.com.au>
Message-ID: <9o5n78.3vv2gu5.1@kserver.org>

On Tue, 18 Sep 2001 13:15:58 +1000, "Peter Moscatt"
 wrote in comp.lang.python in article
<3ba6bd0e at news.iprimus.com.au>:

:I am having difficulty in converting a string to Upercase - how is this best
:achieved ??

mystring = 'cat'
mystring = mystring.upper()
print mystring

The above will work in Python 2.0+

If you are using an older version:

import sting

mystring = 'cat'
mystring = string.upper(mystring)
print mystring

The above will work in all version of Python since 1.5 at least (and
probably before that, too, but you shouldn't be running anything older
than that).

--
Sheila King
http://www.thinkspot.net/sheila/
http://www.k12groups.org/

From grahamd at dscpl.com.au  Fri Sep 21 20:34:05 2001
From: grahamd at dscpl.com.au (Graham Dumpleton)
Date: 21 Sep 2001 17:34:05 -0700
Subject: Python interface for MOM? (No, not the family-friendly person ...)
References: 
Message-ID: 

 wrote in message news:...
> Hi
> 
> Anyone know of a python interface to IBM's MQSeries - or any
> message-oriented middleware?

Depending on what aspects of MOM you are interested in, you might want
to look at OSE.

  http://ose.sourceforge.net

It doesn't have persistent message queues or transactions, but does
support message oriented request/reply and publish/subscribe functionality.

Check out the python manual on the web site.

From zope at thewebsons.com  Thu Sep  6 20:55:56 2001
From: zope at thewebsons.com (Ben Ocean)
Date: Thu, 06 Sep 2001 17:55:56 -0700
Subject: Upgrading
Message-ID: <5.0.2.1.0.20010906175256.00a03e80@thewebsons.com>

Hi;
I get this error message when I try to upgrade to 2-2.1.13 with an rpm on RH62:

error: failed dependencies:
         libcrypto.so.1   is needed by python2-2.1.1-3
         libexpat.so.0   is needed by python2-2.1.1-3
         libgmp.so.3   is needed by python2-2.1.1-3
         libncurses.so.5   is needed by python2-2.1.1-3
         libpanel.so.5   is needed by python2-2.1.1-3
         libreadline.so.4.1   is needed by python2-2.1.1-3
         libssl.so.1   is needed by python2-2.1.1-3

I'm surprised there's any problem at all, which makes me a little worried. 
Before I chase all of these files down (and suggestions about where to find 
them would be nice), I'm equally concerned about going on a mad goose chase 
looking for the files *these* files might need. Any ideas?
TIA,
BenO

From mcfletch at home.com  Tue Sep 25 13:26:03 2001
From: mcfletch at home.com (Mike C. Fletcher)
Date: Tue, 25 Sep 2001 13:26:03 -0400
Subject: Proposal: add vector arithmetic to array module
In-Reply-To: <7xelovql5y.fsf@ruckus.brouhaha.com>
Message-ID: <003201c145e7$288a51c0$0202a8c0@MikeySpace>

Py2Exe and the McMillan installer both do exactly that (package python
scripts as exes with all dependencies).  BTW: I think ActiveState Python is
Win32, Linux and Solaris

Numeric is becoming a very widely used module, so if there is something
going into the core, it would be my vote.  However, I'd still like to see a
better mechanism for distributing extensions (e.g. auto-downloading signed
packages from a Zope server somewhere) so that the list of "included"
modules can _shrink_, rather than grow.

But then everyone wants that,
Mike

-----Original Message-----
From: python-list-admin at python.org
[mailto:python-list-admin at python.org]On Behalf Of Paul Rubin
Sent: September 25, 2001 12:40
To: python-list at python.org
Subject: Re: Proposal: add vector arithmetic to array module
...
> BTW, MacPython includes Numeric, and it is part of the extended module
> support of ActiveState Python, so it's really not hard for your users to
> download.

What if they're not using Macintoshes?

Actually, if we're discussing OS-specific distributions, it would be
good to be able to distribute Windows apps WITHOUT needing the user to
install Python.  That is, I'd like to release a single .exe that
includes my .pyc files, the Python interpreter core, and the minimal
set of libraries needed to make my app run.  Is that feasible with the
stuff you're describing?  I'm a near-total Windows ignoramus.
--
http://mail.python.org/mailman/listinfo/python-list

From maxm at normik.dk  Fri Sep 14 10:29:38 2001
From: maxm at normik.dk (maxm)
Date: Fri, 14 Sep 2001 16:29:38 +0200
Subject: Proposed PEP for a Conditional Expression
References:  <6qvgire4bk.fsf@abnoba.intevation.de> <9nidrm01j7q@enews1.newsguy.com> <23891c90.0109130146.60a98909@posting.google.com>
Message-ID: <3ba21452$0$51376$edfadb0f@dspool01.news.tele.dk>

> In Python, one can use the following instead in this case:
>
>   outputString = otherString or ""
>
> Personally, I find complicated uses of ?: difficult to scan and
> understand rapidly, contrary to spurious arguments about its supposed
> similarity to English language constructs.

Besides ... what could be simpler than using the fact that booleans in
Python is either 1 or 0:

#################################
>>> a=3
>>> b=4
>>> print ('number two', 'number one')[a < b]
>>> number one

or if you want to get the result of a functionwith only the choosen function
evaluated:

#################################
>>> def n1():
>>>     return 'Number one'
>>> def n2():
>>>     return 'Number two'
>>> print (n2, n1)[a < b]()
>>> Number one

Any sane Python programmer will grasp those IMMEDIATELY!

;-)

Regards Max M

From richard at bizarsoftware.com.au  Mon Sep 10 00:48:34 2001
From: richard at bizarsoftware.com.au (Richard Jones)
Date: Mon, 10 Sep 2001 14:48:34 +1000
Subject: Python by RPM -> bad idea?
In-Reply-To: <3b9c40dc_1@news.nwlink.com>
References: <3b9c40dc_1@news.nwlink.com>
Message-ID: <0109101448050G.01597@ike>

On Monday 10 September 2001 14:33, Paul wrote:
> I'm having problems, and I think they stem from my installing Python
> originally through the use of an RPM.
>
> By using an RPM, I get not /config directory with a Makefile, which sounds
> reasonable enough, as I didn't compile anything.

You probably need to install a python-devel RPM. I generally work only from 
RPM on linux (Mandrake) and have had no problems whatsoever.

    Richard

From nas at python.ca  Wed Sep 19 12:41:02 2001
From: nas at python.ca (Neil Schemenauer)
Date: Wed, 19 Sep 2001 09:41:02 -0700
Subject: Code Coverage support for unittest?
In-Reply-To: <3BA8BCD1.3060700@destiny.com>; from mcherm@destiny.com on Wed, Sep 19, 2001 at 10:42:09AM -0500
References: <3BA8BCD1.3060700@destiny.com>
Message-ID: <20010919094102.A21427@glacier.arctrix.com>

Michael Chermside wrote:
> I was reading this:
> 
> http://www.amk.ca/python/writing/mx-architecture/#SECTION000800000000000000000
> 
> and the author referred to using a modified version of Skip Montanaro's 
> trace.py to get CODE COVERAGE reporting for unit tests written using the 
> unittest module.
> 
> Really? How? I must have missed this in the docs! It sounds great... 
> does anyone know the details, or where (if at all) it's documented?

The unittest included with Quixote is not that same as the one released
with 2.1.

  Neil

From mlh at idi.ntnu.no  Thu Sep 27 03:09:50 2001
From: mlh at idi.ntnu.no (Magnus Lie Hetland)
Date: Thu, 27 Sep 2001 09:09:50 +0200
Subject: The status of xmllib
Message-ID: <9oujbu$4pp$1@tyfon.itea.ntnu.no>

What exactly does the following statement from the
documentation (section 13.12, xmllib) mean?

  Deprecated since release 2.0. Use xml.sax instead.

I understand that it encourages people not to use
xmllib, and to use xml.sax... But does it mean that
xmllib will be phased out in the long run? In that
case, is a pure-Python plug-in for xml.sax planned?
If xmllib is here to stay (although not as good as
the xml package), perhaps deprecated is a bit strong?
Or am I just being nervous about it?

And, if no pure-Python handler for xml.sax (or
xml.anything) exists -- would a submitted module
stand a chance of being included? (Not that I have one,
but if it would be used, I might write one...)

- Magnus (who wants an xml package which doesn't strain
the poor users with compiling and installing expat)

--

  Magnus Lie Hetland         http://www.hetland.org

 "Reality is that which, when you stop believing in
  it, doesn't go away."           -- Philip K. Dick

From cgale1 at _remove_home.com  Mon Sep 10 08:05:37 2001
From: cgale1 at _remove_home.com (Van Gale)
Date: Mon, 10 Sep 2001 12:05:37 GMT
Subject: .NET and Python
References:  <9nettc$ce1$1@slb7.atl.mindspring.net>    <8nMm7.133116$n75.31959718@news4.rdc1.on.home.com>  <9ni0fi0vq0@enews1.newsguy.com>
Message-ID: 

"Alex Martelli"  wrote in message
news:9ni0fi0vq0 at enews1.newsguy.com...
> "Van Gale"  wrote in message
> news:g7%m7.226487$%a.8840828 at news1.rdc1.sdca.home.com...
>     ...
> > > I've looked into .NET and I hate to admit it, MS is
> > > become more right lately.
> >
> > Microsoft marketing literature and hype has *always* been right.  For
the
>
> I disagree: I find Microsoft's marketing abysmal in its field.  One

Yeah, I didn't really express that well :)  I was really trying to say
something like with .NET, Microsoft is doing a good job of seeming right.
That doesn't mean they actually are right (at this point).

From rnd at onego.ru  Thu Sep 27 09:41:21 2001
From: rnd at onego.ru (Roman Suzi)
Date: Thu, 27 Sep 2001 17:41:21 +0400 (MSD)
Subject: What happened to Python for BeOS?
Message-ID: 

Can't find Python for BeOS any more...
Any ideas?

Sincerely yours, Roman A.Suzi
-- 
 - Petrozavodsk - Karelia - Russia - mailto:rnd at onego.ru -

From hcj.goudsmit at wanadoo.nl  Tue Sep  4 06:20:27 2001
From: hcj.goudsmit at wanadoo.nl (jeroen paul goudsmit)
Date: Tue, 04 Sep 2001 10:20:27 GMT
Subject: how do i make a grapical thingie?
References:  
Message-ID: 

Ok. Python is instal;led in : C:\Python22.  The name of the executable is =
C:\Python22\python.exe. The dll files are in the map C:\Python22\DLLs. The
tkinter file is C:\Python22\DLLs\_tkinter.pyd.
"Maan Hamze"  schreef in bericht
news:HQOk7.217122$g_3.41849242 at typhoon.austin.rr.com...
> Tim
> The guy had not even answered on how he has Python installed to start
with.
> To recommend Jython for him at this stage along with the use of AWT or
swing
> is an overkill :)
> Maan
>
> "Delaney, Timothy"  wrote in message
> news:mailman.999478982.9172.python-list at python.org...
> > I suspect the simplest thing here would be to use Jython and AWT or
Swing.
> >
> > http://www.jython.org
> >
> > Probably the easiest way for a beginner to get a GUI up and running in
> > Python. Once they have a bit more experience they can move onto other
> > things.
> >
> > Tim Delaney
> >
>
>

From gh_pythonlist at gmx.de  Sun Sep 30 01:56:40 2001
From: gh_pythonlist at gmx.de (Gerhard =?iso-8859-1?Q?H=E4ring?=)
Date: Sun, 30 Sep 2001 07:56:40 +0200
Subject: Error keeps coming up
In-Reply-To: <9p6ba8$8qf$1@ins22.netins.net>; from rwhite@netins.net on Sun, Sep 30, 2001 at 12:41:54AM -0500
References: <9p6ba8$8qf$1@ins22.netins.net>
Message-ID: <20010930075639.C1967@lilith.hqd-internal>

On Sun, Sep 30, 2001 at 12:41:54AM -0500, Ron White wrote:
> I installed 2.1.1 Python on a win me machine and when I run a program that
> has an error (like a syntax error) I continue to get that same error even
> when I  try to run  another program.  How do I get rid of the first program
> so it's error doesn't keep coming up?

Sounds very strange and unlikely. Can you send us the sources of the two
programs? And also how you invoked them. Double-clicking from Explorer
or how you invoked them from the commandline.

Gerhard
-- 
mail:   gerhard  bigfoot  de       registered Linux user #64239
web:    http://www.cs.fhm.edu/~ifw00065/    OpenPGP public key id 86AB43C0
public key fingerprint: DEC1 1D02 5743 1159 CD20  A4B6 7B22 6575 86AB 43C0
reduce(lambda x,y:x+y,map(lambda x:chr(ord(x)^42),tuple('zS^BED\nX_FOY\x0b')))
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From mmhamze at pleiades.net  Sun Sep  2 10:03:25 2001
From: mmhamze at pleiades.net (Maan Hamze)
Date: Sun, 02 Sep 2001 14:03:25 GMT
Subject: COM MakePy utility in PythonWin
References:  <3b91e631.1383281@news.t-online.de>
Message-ID: 

"Gerson Kurz"  wrote in message
news:3b91e631.1383281 at news.t-online.de...
> On Sun, 02 Sep 2001 05:09:43 GMT, "Maan Hamze" 
> wrote:
> >2.  I have a povray modelling program that offers a COM interface.  I was
> >able to connect to it through Hammond's Python win32com.  But the
interface
> >itself is not listed in the COM browser in PythonWin.  I looked for it in
> >the registry and found it and tried it in PythonWin and it worked.  I am
> >just wondering why the object did not appear in the COM Broswer?
>
> - do you implement IDispatch ? COM alone (eg. IUnknown + custom
> derived interface) isn't enough to be usable in Python (or VB).
>
I just went by the default installation of the povray program (Breeze
Designer).  It implements the COM object Breeze.Scene which is in the
registry but does not appear in the COM browser.  I tired it with:
>>> import win32com.client
>>> scene=win32com.client.Dispatch("Breeze.Scene")
and it worked.  I was able to control the program.

> - Do you have the .tlb properly registered ?
>
No it is not (Breeze20.tlb) and it would not register.  I contacted the
developer of Breeze about this and about other issues connected with running
Python also in Breeze internal macro engine that allows for Python
ActiveScripting.
Maan
>

From grante at visi.com  Mon Sep 24 11:47:05 2001
From: grante at visi.com (Grant Edwards)
Date: Mon, 24 Sep 2001 15:47:05 GMT
Subject: Outlook COM access warning dialog?
Message-ID: 

In an (IMO futile) effort to plug one of the many gaping
security holes designed into MS produts, BOFH has installed an
Outlook security update.  Now anytime a Python program uses
Outlook's COM interface, a warning dialog pops up that has to
be clicked on 3 times to make it go away and allow the COM
access.

Does anybody know how to disable that warning?

-- 
Grant Edwards                   grante             Yow!  -- I can do
                                  at               ANYTHING... I can
                               visi.com            even... SHOPLIFT!!

From aahz at panix.com  Thu Sep  6 14:54:12 2001
From: aahz at panix.com (Aahz Maruch)
Date: 6 Sep 2001 11:54:12 -0700
Subject: Generators and exceptions (was Re: Stackless Python and Python 2.x)
References: 
Message-ID: <9n8gok$mum$1@panix2.panix.com>

In article ,
Tim Peters  wrote:
>[Aahz]
>> 
>> The part I don't understand (though if I had access to 2.2a2, I could
>> probably test it easily enough) is what happens when you re-enter a
>> generator and trigger an exception (an exception that isn't
>> StopIteration, for any smartasses out there).
>
>Nothing special:  the exception is caught by the frame or not, and if not
>propagates out of the frame.  Generators do nothing special at all here, and
>since they always return to their immediate invoker, there are no debatable
>issues about *which* frame *to* propagate an uncaught exception (general
>coroutines are muddier in this respect, and general continuations even
>worse).

Okay, I've re-read PEP 255, and I'm still not clear on what happens with
the following code:

def a():
    yield 1
    raise "foo"
    yield 2
    return

def b():
    return a()

g = b()
g.next()
g.next()

(If I've messed up the syntax, please feel free to correct it before
answering; I *think* my intent is clear enough.)
-- 
                      --- Aahz  <*>  (Copyright 2001 by aahz at pobox.com)

Hugs and backrubs -- I break Rule 6                 http://www.rahul.net/aahz/
Androgynous poly kinky vanilla queer het Pythonista   

"Plus ca change, plus c'est la meme chose."

From rnd at onego.ru  Sun Sep 16 08:36:16 2001
From: rnd at onego.ru (Roman Suzi)
Date: Sun, 16 Sep 2001 16:36:16 +0400 (MSD)
Subject: Flatfile update?
In-Reply-To: <20010916.125521.1909002904.11525@mailandnews.com>
Message-ID: 

On Sun, 16 Sep 2001, pwgk wrote:

>Hi,
>I am trying to find out if it is possible to open a flat (ascii) file for
>update in python, so I can change it's contents directly, without having
>to copy the entire contents.

It depends on the format of flat file. If you have fixed length lines,
you can change text file inplace using positioning by seek() method.
(But open file as binary for that, if your platfrom distinguishes
text/binary file modes).

>Is this possible, and if yes, does anyone know how?
>Or do I have to start digging into MySQL for that?

It depends on what you want to achieve. If your application has 1-2-3
flatfile dbs and there is no relational db readily running, flat files are
fine. (I could dare to say, they are much more secure than say MySQL.)

However, if you envision that your system will grow, you are better off
with RDBMS as soon in the development, as possible, or you will end with
numerous flat files scattered accross your system.

If you want simultaneous write access, consider locking file (or record
of file) you are accessing. (look at the fcntl module)

>Regards
>Paul

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Sunday, September 16, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "Phobia: what's left after drinking 2 out of a 6 pack" _/

From slinkp23 at yahoo.com  Tue Sep 18 23:23:12 2001
From: slinkp23 at yahoo.com (Paul Winkler)
Date: Wed, 19 Sep 2001 03:23:12 GMT
Subject: LoD questions
References:  <3BA7B1B2.E8874ED5@accessforall.nl>
Message-ID: 

On Tue, 18 Sep 2001 21:42:46 +0100, Ype Kingma  wrote:
>When you find yourself writing foo.bar.bat a lot of times in the
>methods of the class of foo, it 
>is reasonable to consider foo.bar.bat a "close friend" of foo,
>so you introduce:
>    foo.bat = foo.bar.bat
>at an appropriate place, possibly in the __init__() method.
>This is more concise, and more efficient.
>It also reduces the need for get_bar_bat_baz() methods considerably.

Hmm, yes, I've been overlooking that. Looks like it might be a useful
technique in some parts of my current project. Thanks!

--PW

From nospam at bigfoot.com  Thu Sep 27 13:06:10 2001
From: nospam at bigfoot.com (Gillou)
Date: Thu, 27 Sep 2001 19:06:10 +0200
Subject: Is xmlrpclib slow?
References: <9ov48m$eao$1@tyfon.itea.ntnu.no>
Message-ID: <9ovlv0$1aaq$1@norfair.nerim.net>

Its strongly recommanded to install "sgmlop" as indicated in the comments of
xmlrpclib.py.

#
# Notes:
# this version uses the sgmlop XML parser, if installed.  this is
# typically 10-15x faster than using Python's standard XML parser.
#
# you can get the sgmlop distribution from:
#
#    http://www.pythonware.com/madscientist

Hope the future xmlrpclib will use the new PyXML package in place of the
_nearly deprecated_ xmllib.

--Gillou

From jdhunter at nitace.bsd.uchicago.edu  Mon Sep 10 12:50:32 2001
From: jdhunter at nitace.bsd.uchicago.edu (John Hunter)
Date: 10 Sep 2001 11:50:32 -0500
Subject: CrossProductSweeper
References: <1rn1439eux.fsf@video.bsd.uchicago.edu>
Message-ID: <1rheub9ehz.fsf@video.bsd.uchicago.edu>

Oops: there was as indentation problem in one of the examples in the
docs above.  The 'just finished y' example should read:

for x in (1,2,3,4):
   for y in (5,6):
      for z in (7,8,9,10):
         pars = (x,y,z)
   print 'Just finished y'

Not:

for x in (1,2,3,4):
   for y in (5,6):
      for z in (7,8,9,10):
         pars = (x,y,z)
      print 'Just finished y'

JDH

From nas at python.ca  Fri Sep 21 16:46:15 2001
From: nas at python.ca (Neil Schemenauer)
Date: Fri, 21 Sep 2001 13:46:15 -0700
Subject: mkstemp vs. tmpnam , tempnam
In-Reply-To: ; from zptang@hotmail.com on Fri, Sep 21, 2001 at 01:21:22PM -0700
References: 
Message-ID: <20010921134615.A25437@glacier.arctrix.com>

Janet wrote:
> I am running it on Linux, Mandrake 8.0.  Both tmpnam and tempnam are
> considered unsafe.  Is there a patch for this problem or I can just
> modified the Modules/posixmodule.c to use msktemp instead?

Don't worry about it.  Python doesn't use those functions unless you do.
If you're really paranoid you could remove those functions from
posixmodule.

  Neil

From skip at pobox.com  Thu Sep 27 19:51:01 2001
From: skip at pobox.com (Skip Montanaro)
Date: Thu, 27 Sep 2001 18:51:01 -0500
Subject: scanf style parsing
In-Reply-To: 
References: <3BB16A50.BAE082FE@cygnus-software.com>

        <3BB2C7DA.F63EEAA7@cygnus-software.com>

Message-ID: <15283.47973.96356.551360@beluga.mojam.com>

    >> maybe-the-best-argument-against-vi-ly, yr's

    Tim> This I don't understand.  Where was the argument against vi?

I guess you didn't see the implied smiley.

Skip

From slhath at home.com  Tue Sep 25 22:05:59 2001
From: slhath at home.com (Scott Hathaway)
Date: Wed, 26 Sep 2001 02:05:59 GMT
Subject: Win32 / IIS: Creating virtual directories
References: <3bb0393d.87609896@news.mch.sni.de>
Message-ID: 

Look at many sample scripts in the inetpub\AdminScripts directory under IIS.

Scott

"Nikolai Kirsebom"  wrote in message
news:3bb0393d.87609896 at news.mch.sni.de...
> I have IIS running on NT 4 - where I have some ASP pages with Python
> code.  The whole thing had to be reinstalled lately because of Nimda.
> The process of reinstalling everything (virtual web-servers,
> ftp-account, users, user-groups) is a tedious task - so now I would
> like to make some scripts to make it easier next time (hopefully
> never) I have to do the job again.  I'll use the win32net module for
> manageing users / groups.  However, does anyone know where I can find
> information / hint on how to programatically configure IIS (both web
> and ftp part) including creating virtual directories.
>
> Thanks for any help
> Nikolai Kirsebom
>

From nas at python.ca  Mon Sep 24 16:42:22 2001
From: nas at python.ca (Neil Schemenauer)
Date: Mon, 24 Sep 2001 13:42:22 -0700
Subject: Simple process IO capture (Was: "shell-commands" and python!)   - process.py (0/1)
In-Reply-To: <4u4vqts8urqfa5n6t2ih3n38il5fm5ats3@4ax.com>; from gustav@morpheus.demon.co.uk on Mon, Sep 24, 2001 at 09:14:42PM +0100
References:   <4u4vqts8urqfa5n6t2ih3n38il5fm5ats3@4ax.com>
Message-ID: <20010924134222.A1597@glacier.arctrix.com>

Here's my humble attempt at a popen replacement.  Note that it doesn't
use the shell (a feature IMHO) and it only works on Unix systems.
Suggestions for the module name are welcome.  I would like to get
something like this in the standard library.

  Neil

###########################################################################
# child_process.py
###########################################################################
import os

# created 2001/09/04, nas

class _ChildProcess:
    """
    Instance attributes:

        pid : int
          the process id of the child process
        stdin : file
          open file connected to file descriptor 0 of the child process
        stdout : file
          open file connected to file descriptor 1 of the child process
        stderr : file
          open file connected to file descriptor 2 of the child process
    """

    MAXFD = 256

    def __init__(self, argv, bufsize=-1):
        child_stdin, stdin = os.pipe()
        stdout, child_stdout = os.pipe()
        stderr, child_stderr = os.pipe()
        self.stdin = os.fdopen(stdin, 'w', bufsize)
        self.stdout = os.fdopen(stdout, 'r', bufsize)
        self.stderr = os.fdopen(stderr, 'r', bufsize)
        self.pid = os.fork()
        if self.pid == 0:
            os.dup2(child_stdin, 0)
            os.dup2(child_stdout, 1)
            os.dup2(child_stderr, 2)
            for i in range(3, self.MAXFD):
                try:
                    os.close(i)
                except:
                    pass
            try:
                os.execvp(argv[0], argv)
            finally:
                os._exit(1)
        os.close(child_stdin)
        os.close(child_stdout)
        os.close(child_stderr)

    def read(self, n=-1):
        """Read from child stdout"""
        return self.stdout.read(n)

    def readline(self):
        """Readline from child stdout"""
        return self.stdout.readline()

    def readlines(self):
        """Readlines from child stdout"""
        return self.stdout.readlines()

    def write(self, s):
        """Write data to child stdin"""
        self.stdin.write(s)

    def flush(self):
        """Flush stdin pipe to child"""
        self.stdin.flush()

    def close(self):
        """Close stdin, stdout and stderr pipes to child process.  Wait
        for the exit status of the child and return it."""
        for fd in (self.stdin, self.stdout, self.stderr):
            if not fd.closed:
                fd.close()
        status = self.wait()
        if status == 0:
            return None # matches behavior of popen(...).close()
        else:
            return status

    def wait(self, flags=0):
        pid, status = os.waitpid(self.pid, flags)
        return status

def execute(argv, bufsize=-1):
    r"""execute(argv : (string*), bufsize=-1) -> _ChildProcess

    Create a child process with pipes connected to its stdout, stdin and
    stderr file descriptors.  The child is created using fork() and
    execvp() in order to avoid the argument quoting problems presented by
    using system() or popen().  The bufsize argument has the same meaning as
    for the open() builtin and applies to stdin, stdout, and stderr.

    Examples:

        >>> p = execute(("ls", "/"))
        >>> p.readline()
        'bin\n'
        >>> p.readline()
        'boot\n'
        >>> p.close()
        >>>

        >>> p = execute(("cat",))
        >>> p.write("hello world\n")
        >>> p.stdin.close()
        >>> p.read()
        'hello world\n'
        >>> p.close()
        >>>

    """
    return _ChildProcess(argv, bufsize)

From comments at cygnus-software.com  Thu Sep 27 22:39:47 2001
From: comments at cygnus-software.com (Bruce Dawson)
Date: Fri, 28 Sep 2001 02:39:47 GMT
Subject: scanf style parsing
References: <3BB16A50.BAE082FE@cygnus-software.com>  <8351bb33.0109270648.75af3371@posting.google.com>
Message-ID: <3BB3E270.8D10F86B@cygnus-software.com>

And a good thing to - otherwise the scanf/regexp job would
be a bit more complicated.

Jon Nicoll wrote:

> trivial followup: isn't it ... amazing ... the number of programs
> which still have this kind of output?
>
> > >
> > > smtpmail.exe - 0 error(s), 0 warning(s)
>                           ___           ___
>
>     jon N

From ignacio at openservices.net  Wed Sep 19 15:11:59 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Wed, 19 Sep 2001 15:11:59 -0400 (EDT)
Subject: SWIG: MSVC++ [LINK : fatal error LNK1104: cannot open file 
 "python21_d.lib"]
In-Reply-To: <3BA8E9CE.638D69D5@northwestern.edu>
Message-ID: 

On Wed, 19 Sep 2001, Louis Luangkesorn wrote:

> I searched my Python installation and I don't see a 'python21_d.lib' file
> anywhere.  I've already located the 'python21.lib' as a required library.
> Where should "python21_d.lib" be located, or is this something I need to
> download/write?  Thanks.

The _d library should only be required if you're doing a debug build. If you
change to a release build you should be fine.

-- 
Ignacio Vazquez-Abrams  

From des.small at bristol.ac.uk  Thu Sep 13 10:21:48 2001
From: des.small at bristol.ac.uk (Des Small)
Date: Thu, 13 Sep 2001 14:21:48 GMT
Subject: time module error.
Message-ID: 

Yow!

I want to have a time class, with instances I can add to in hours.
Rather than reinvent the wheel, I want to use the standard time
module, but as the transcript below shows, I have trouble.

==========8<==============================================
Python 2.1 (#1, May  3 2001, 12:58:02) 
[GCC 2.96 20000731 (Red Hat Linux 7.1 2.96-81)] on linux2
Type "copyright", "credits" or "license" for more information.
>>> import time
>>> t = time.strptime( '2',"%H")
>>> t
(1900, 1, 0, 2, 0, 0, 6, 1, 0)
>>> time.mktime(t)
Traceback (most recent call last):
  File "", line 1, in ?
OverflowError: mktime argument out of range
===========8<==============================================

Now, I can easily enough convert hours to seconds in my own code, but
I don't understand why the above fails.  

Any pointers?

Des.
-- 
Dr Des Small, Scientific Programmer,
School of Mathematics, University of Bristol,
Tel: 0117 9287984

From ralph at inputplus.demon.co.uk  Mon Sep 10 06:41:30 2001
From: ralph at inputplus.demon.co.uk (Ralph Corderoy)
Date: 10 Sep 2001 11:41:30 +0100
Subject: How come tuples don't have an index method?
References: 
Message-ID: <9ni5cq$90v$1@inputplus.demon.co.uk>

Hi Tim,

> >  Would be nice to be consistent, espcecially within a single
> >  module.
> 
> It's unusually common in the operator module:  countOf, indexOf,
> isCallable, isMappingType, isNumberType, isSequenceType,
> sequenceIncludes.

It's very much a minority in the operator module, and for two of
those...

    isCallable           deprecated since 2.0, use callable instead

    sequenceIncludes     deprecated since 2.0, use contains instead
        (contains added by Guido)

> >  getitem isn't getItem so why not countof?
> 
> If you really believe there's an objective reason, and that you can
> convince the author they were wrong, feel encouraged to find the
> author via CVS and engage them in productive debate  .

CVS only goes back to 2.1?  From that it looks like Guido did most of
it with Fred Drake making minor changes more recently.  But I can't
tell if many hands were involved before 2.1 leading to the mixture of
naming styles.

    http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/python/python/dist/src/Modules/operator.c

Consistency is a nice attribute to have.  Not just in naming
conventions but also the interface a module presents.  Is effort needed
to improve the standard library so it's more consistent?  If so, would
that be welcomed?

Ralph.

From cb921 at voice.co.za  Tue Sep 25 04:47:13 2001
From: cb921 at voice.co.za (Campbell)
Date: Tue, 25 Sep 2001 10:47:13 +0200
Subject: exposing #defines in an extension module
Message-ID: 

Hi,

I am trying (without SWIG which is a very nice program) to create an
extension module working on xxmodule.c from the distribution.  All my
functions are groovy, and now I have several thousand lines of
#define .... to deal with.

I've thought of setting them using Object_setattr(), and I've thought
of just setting them in the .py which will wrap this module.  But is
there any commonly used mechanism to get them in automatically?  There
really is an astonishing (to me) amount of them.

Thanks again,
Campbell

From brianmce at crosswinds.net  Wed Sep 12 10:54:11 2001
From: brianmce at crosswinds.net (Brian McErlean)
Date: 12 Sep 2001 07:54:11 -0700
Subject: Some ideas for Pymacs
References: 
Message-ID: <6e0ad3b1.0109120654.421332a5@posting.google.com>

pinard at iro.umontreal.ca (=?iso-8859-1?q?Fran=E7ois?= Pinard) wrote in message news:...
> Hi, people.
> 
> 
> I guess the most important improvement we could think to Pymacs would
> be some machinery by which Python programs, started outside Emacs, could
> access Pymacs, once it started.  That could be useful at least for testing
> or debugging, and maybe for more serious work as well.  These are mere
> thoughts, I do not plan working at this soon, unless I have an actual need.
> But if the challenge interests someone, please go ahead!

This would raise the almost blasphemous possibility of driving Vim (with 
python scripting) in emacs.  I'm not sure if that's possible without the 
universe exploding in a storm of antimatter - but the idea does have a 
certain appeal :-)

> Here is how it could go.  Pymacs has a Python interpreter running as a
> sub-process of Emacs.  In fact, Emacs loads `pymacs.el', which in turn
> gets Python to execute `pymacs.py', and both communicate afterwards.
> `pymacs.py' is only active whenever `pymacs.el' calls it, otherwise it
> is blocked.  `pymacs.py' could, under some option, start another thread
> within itself.  The initial thread would block waiting for Emacs, as usual.
> The second thread would block waiting to serve any Python client wanting to
> access Emacs.  When this occurs, the second thread would queue a request
> for the first thread, and then send a signal to Emacs so it triggers a
> Pymacs communication.  At each communication opportunity, the first thread
> on the Python side might fully service the queue from the second thread.
> 

I think this should be possible, but some of the details may be very tricky.
Probably the trickiest part is signalling emacs to deal with pending python
requests - this could maybe be done with a timeout, or some kind of external
signal,  but in either case there needs to be a check that you are not in the
middle of processing other requests!

This could be a very cool feature though - remotely drive emacs using
python.

-- 
Brian McErlean

From aahz at panix.com  Thu Sep  6 20:35:20 2001
From: aahz at panix.com (Aahz Maruch)
Date: 6 Sep 2001 17:35:20 -0700
Subject: Editing a file 'In Place'
References: <3b97ed74.472037594@news.demon.co.uk>
Message-ID: <9n94o8$pb3$1@panix2.panix.com>

In article <3b97ed74.472037594 at news.demon.co.uk>,
Simon Foster  wrote:
>
>I'm trying to write a simple piece of code to perform some batch edits
>on a text file.  So far I have:

import fileinput
-- 
                      --- Aahz  <*>  (Copyright 2001 by aahz at pobox.com)

Hugs and backrubs -- I break Rule 6                 http://www.rahul.net/aahz/
Androgynous poly kinky vanilla queer het Pythonista   

"Plus ca change, plus c'est la meme chose."

From loewis at informatik.hu-berlin.de  Fri Sep 21 11:44:21 2001
From: loewis at informatik.hu-berlin.de (Martin von Loewis)
Date: 21 Sep 2001 17:44:21 +0200
Subject: validating xml parser?
References: 
Message-ID: 

"Narayan Desai"  writes:

> Hi. I have been looking for a validating XML parser for python that
> includes schema support. It looks like there is a xerces based parser
> module. It seems to support schemas. Can parser backends be
> coerced into looking like either sax or dom, or will a module only be
> implimented for one? 

Usually, you'd create a parser module that offers a SAX parser only;
it can then be used to build DOM trees. If the parser has its own DOM
implementation, you could also expose that - but that's quite some
work to wrap all the classes.

> I have found a number of validating parsers that implement at least
> SAX support, but I would really like to use one that does dom as
> well. Is there some comprehensive documentation I should be reading
> someplace? I can find specific examples, but no generic info about
> how the whole subsystem works...

Not sure what "the whole subsystem" is. If you have a SAX parser, and
you want to create a DOM tree, you can use pulldom to create a minidom
tree, and xml.dom.ext.reader.Sax2 to create a 4DOM tree.

Regards,
Martin

From armin.samide at avl.com  Thu Sep  6 06:57:01 2001
From: armin.samide at avl.com (Armin Samide)
Date: 6 Sep 2001 03:57:01 -0700
Subject: PyRun_SimpleFile ?
Message-ID: <21691e22.0109060257.6237bfec@posting.google.com>

Hi,

i'am trying to start a python file out of c++ program by
PyRun_SimpleFile().
Looks like this:

#include 
#include "Python.h" 

void main (int argc, char **argv) { 

	Py_Initialize ();

	FILE *fp      = fopen ("test.py",   "r+");
	FILE *foxfile = fopen ("gltest.py", "r+");

	PyRun_SimpleFile (fp, "test.py");

	PyRun_SimpleFile (foxfile, "gltest.py");

	Py_Exit(0);
} 

The file test.py is executed without problem ( simply contains one
print statement ) but the file gltest makes use of the fox - python
binding.
If i start the file gltest.py from the command line ( python gltest.py
) everything is fine but out of that program i get:

Traceback (most recent call last):
  File "gltest.py", line 3, in ?
    from FXPy.fox import *
  File "E:\Programme\Python21\FXPy\__init__.py", line 4, in ?
    from fox import setErrorObject
  File "E:\Programme\Python21\FXPy\fox.py", line 2, in ?
    import foxc
ImportError: No module named foxc

Do I have to set up something extra, but the other file ( fox.py,
__init__.py ) are found and foxc.pyd also exists.

Is it possible to staticly include the fox part in thew python
interpreter and can you give me some tipps who to do that ?

thank a lot,
armin

From aaronf at NOSPAMtelusplanet.net  Sun Sep 23 22:12:18 2001
From: aaronf at NOSPAMtelusplanet.net (Aaron Fransen)
Date: Mon, 24 Sep 2001 02:12:18 GMT
Subject: New Python WebMail app
References:   <9oc646$dmd$1@serv1.iunet.it>
Message-ID: <6Ewr7.17203$9j.3347364@news1.telusplanet.net>

I don't see any restriction on the src attribute itself, but what I should
probably investigate is the "designmode" attribute that IE uses for IFRAME.
This is the attribute that can turn an IFRAME window into an edit region.

"Alex Martelli"  wrote in message
news:9oc646$dmd$1 at serv1.iunet.it...
>
> See: http://www.w3.org/TR/REC-html40/present/frames.html#edef-IFRAME
> Do you see any constraints there on what can go to the src attribute
> of an iframe...?
>
>
> Alex

From heikowu at ceosg.de  Thu Sep 20 18:23:19 2001
From: heikowu at ceosg.de (Heiko Wundram)
Date: Fri, 21 Sep 2001 00:23:19 +0200
Subject: How to do * and & C-lang. operations in Python?
In-Reply-To: 
References: 
Message-ID: <01092100225700.00319@phoenix>

On Thursday 20 September 2001 19:00, you wrote:
> On 20 Sep 2001, Toni Gaya wrote:
> > Assignaments are done by 'value', not by 'reference'. Function calls
> > are done by 'reference'. How to do assignaments by reference?. In C
>
> Check Google Groups for the answer.
>
> > Another question:
> >
> > module1:
> > 	import module2
> >
> > module2:
>
> import module1

This shouldn't work, as cyclic imports can't be resolved at runtime (at least 
in my projects it always failed...)!

Just put the import module2 at the end of module1 (when you run/import 
module1 from an external program as the first item).

What this does is that all code in module1 has already been parsed when 
module2 is imported, which imports back module1, which has already been 
parsed, and Python doesn't complain anymore.

If you do any kind of cyclic imports, be sure to check this, as it gives rise 
to all kinds of quirky errors that may actually seem like resulting from 
somewhere else. And be sure to obey the order!

Code Example:

module1:

	import module2

module2:

	import module1

mainprog:

	import module1
	import module2

-- 
Yours sincerely,

	Heiko Wundram

From info at djslim.com  Sun Sep  2 02:18:32 2001
From: info at djslim.com (Seung Chan Lim)
Date: Sun, 2 Sep 2001 02:18:32 -0400
Subject: pyDox 0.5a - first Alpha release
References: 
Message-ID: <000b01c13377$1b828d30$0e1dc997@djslim>

pyDox v0.5a

Download URL:
 http://www.djslim.com/djslim3/files/pyDox.tar.gz

What is it?

 Using the inspect module it grabs all the information needed from a python
module
 and generates an XML-based documentation. The enclosed XSL and CSS file
 can transforms the XML file into an XHTML document for viewing.

Requirements:
 Should run under python 1.5.2 and above assuming that the inspect module
works
 under it

License:
    LGPL

Contact:
    dev at djslim.com

slim

From boyd at insultant.net  Tue Sep 25 00:11:21 2001
From: boyd at insultant.net (Boyd Roberts)
Date: Tue, 25 Sep 2001 06:11:21 +0200
Subject: Best way to learn Python?
References: <_qir7.7082$Ck.1324782@news6-win.server.ntlworld.com> <20010923182907.28933.00000349@mb-cl.aol.com> 
Message-ID: <9op0b6$d9i$1@quark.noos.net>

read, write, learn, loop.

From aleax at aleax.it  Mon Sep  3 07:21:10 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 3 Sep 2001 13:21:10 +0200
Subject: COM/CORBA/DCOP (was: Hello people. I have some questions)
References:  <7xsne7en0r.fsf@ruckus.brouhaha.com>
Message-ID: <9mvp3505rt@enews2.newsguy.com>

"Paul Rubin"  wrote in message
news:7xsne7en0r.fsf at ruckus.brouhaha.com...
> Bruce Sass  writes:
    ...
> > I'm hoping Alex M. gets his Linux systems setup soon and starts
> > delving into the matter.
>
> Yes, that will be interesting.

Alex M. has determined he needs a *solid*, _minimalistic_
router/firewall/proxy setup first, and so he has (for the
moment) turned to OpenBSD, where he's reveling in the sheer
purity of implementing a light-maintenance-load, *secure*,
high-performance firewall-etc setup on a Pentium-90,
64-MB, 2GB-disk, 2-ISA-NIC's found lying around in a
dustbin somewhere (the only concession to featuritis
being, obviously, a Python 2 installation!-).

A.M.'s expected to be back to the features-rich, GUI-rich,
Athlon-1.33GHz-at-a-minimum world of Windows-XYZ, Linux
Mandrake/RedHat/SUSE, etc, reasonably soon (don't be
surprised if XPCOM is what he ends up exploring in that
realm, though:-).  But, boy, the *joys* of ipf and ipnat
versus IPTables (and let's not even mention ipchains,
ipfwadm, etc, nor, of course, the utter lack of any such
indispensable tools as part of Win32 protocol stacks!-)...

Alex

From chrishbarker at home.net  Mon Sep 17 16:03:52 2001
From: chrishbarker at home.net (Chris Barker)
Date: Mon, 17 Sep 2001 13:03:52 -0700
Subject: Mac python and Carbon
References: 
Message-ID: <3BA65728.C5C8FC8F@home.net>

Richard Jones wrote:
> Just curious about where Carbon stands in the Grand Scheme of Mac Python.
> 
> Ideally, I'd love to see it available to "regular" python (not the special
> one distributed as MacPython) just like other GUIs. That allowing it to then
> be available to anygui, which in turn allows us to develop kick-ass
> cross-platform win32/mfc and osx/carbon applications with ease :)
> 
> Pipe dream?

Nope. I'm pretty sure Jack is planning on merging MacPython and Unix
Python on OS-X, so that the Mac stuff will just be extra modules... he's
making a lot of progress, check out the MacPython mailing list for more
info.

Personally, I think AnyGUI is a pipe dream anyway... Why you would want
a wrapper around a wrapper around a wrapper around a tool kit is beyond
me:

AnyGUI->wxPython->wxWindows->Win32|GTK|Carbon

All you are going to get is a more limited subset of GUI functionality,
and probably worse performance. I really don't see the point.

I you want a more Pythonic, cleaner interface for GUI programming, I do
see the point, but targeting ALL GUI toolkits seems like a difficult and
limiting idea. I would love to see a thicker wrapper around wxWindows,
for instance (wxWindows because it has the broadest support for various
platforms, including macOS and OS-X). The PythonCard project seems to be
making a nice start on this. A Native Python GUI would be even better,
but that is a monsterous project.

Anyway, clearly the AnyGUI contirbuters do think it's a good idea, so
maybe once it reaches some maturity, I will see the point.

-Chris

-- 
Christopher Barker,
Ph.D.                                                           
ChrisHBarker at home.net                 ---           ---           ---
http://members.home.net/barkerlohmann ---@@       -----@@       -----@@
                                   ------@@@     ------@@@     ------@@@
Oil Spill Modeling                ------   @    ------   @   ------   @
Water Resources Engineering       -------      ---------     --------    
Coastal and Fluvial Hydrodynamics --------------------------------------
------------------------------------------------------------------------

From junkster at rochester.rr.com  Thu Sep 13 05:49:36 2001
From: junkster at rochester.rr.com (Benjamin Schollnick)
Date: Thu, 13 Sep 2001 09:49:36 GMT
Subject: McMillan Installer or Py2Exe?
References: <270c68fe.0109051808.600a9a82@posting.google.com> 
Message-ID: 

In article ,
 David Bolen  wrote:

> web.mail at lycos.com (Alan Green) writes:
> 
> > We've used the McMillan Installer very successfully, but we're just
> > starting a new project and there also seems to be quite a buzz around
> > py2exe.
> > 
> > Has anybody experience of both the McMillan Installer and Py2Exe and
> > care to comment on their relative strengths?
> 
> My suggestion is to grab each, and then try to use it for the
> application in question.  My impression has been that they are both
> very functional, but that sometimes one does better than the other for
> a particular scenario, or that they sometimes leapfrog each other in
> handling strange and interesting import cases.
> 
> For my personal use, I've tried each and have stuck with installer,
> since it's always worked for me, and on my last attempt at a
> comparison it built an application of mine without any problems while
> I had difficulties with py2exe.  But others on this group have
> reported exactly the opposite results, and it's not much effort to
> give each a shot, so getting direct experience may be the best.
> 
> And if one seems more complicated or less understandable to you than
> the other, that's another metric for your own comparison :-)

I've got to vote for Gordon's Installer...

As people have said, try both and see what results you end up
with....  But as I've said, Gordon's package can look intimidating due 
to all the customizable features but 90-95% of the time, you'll never 
need to touch them.

         - Benjamin

From garth_grimm at hp.com  Thu Sep 13 15:46:50 2001
From: garth_grimm at hp.com (Garth Grimm)
Date: Thu, 13 Sep 2001 12:46:50 -0700
Subject: unicode strings and such
References: 
Message-ID: <3BA10D2A.30503@hp.com>

Ignacio Vazquez-Abrams wrote:

>>Any idea of what the str() is actually doing here?  If I remove the str() statements from the
>>following code, I get different resuts (i.e. no substitutions will take place in qt).  So either
>>pattern and patch (after the assignment at the beginning of the loop) aren't actually string
>>objects, or str() is doing something more than the API docs state -- "For strings, this returns the
>>string itself."
>>
> 
> I still can't read the UTF-8 properly. Do the following and show me what your
> results are:
> 
> ---
> 
>>>>a='?f~?f??f--'
>>>>a
>>>>
> '\xe3f~\xe3f\xab\xe3f--'
> 
>>>>str(a)
>>>>
> '\xe3f~\xe3f\xab\xe3f--'
> 
>>>>unicode(str(a), 'utf-8')
>>>>
> Traceback (most recent call last):
>   File "", line 1, in ?
> UnicodeError: UTF-8 decoding error: invalid data
> 
> ---
Not sure if any of this will be helpful.  In both cases, I'm cutting and pasting from a Unicode text editor.

With an NT console command line, I get...

Python 2.0.1 (#18, Jun 22 2001, 02:26:03) [MSC 32 bit (Intel)] on win32
Type "copyright", "credits" or "license" for more information.
 >>> a='(???)(\d{3})'
 >>> a
'(???)(\\d{3})'
 >>> str(a)
'(???)(\\d{3})'
 >>> unicode(str(a), 'utf-8')
u'(???)(\\d{3})'

Using IDLE 0.6, the characters from the cut-n-paste to initialize a look perfect (still Japanese glyphs),

but when I hit ENTER, I get the following dump...

 >>> Exception in Tkinter callback
Traceback (most recent call last):
   File "e:\python20\lib\lib-tk\Tkinter.py", line 1287, in __call__
     return apply(self.func, args)
   File "E:\PYTHON20\Tools\idle\PyShell.py", line 579, in enter_callback
     self.runit()
   File "E:\PYTHON20\Tools\idle\PyShell.py", line 598, in runit
     more = self.interp.runsource(line)
   File "E:\PYTHON20\Tools\idle\PyShell.py", line 183, in runsource
     return InteractiveInterpreter.runsource(self, source, filename)
   File "e:\python20\lib\code.py", line 61, in runsource
     code = compile_command(source, filename, symbol)
   File "e:\python20\lib\codeop.py", line 61, in compile_command
     code = compile(source, filename, symbol)
UnicodeError: ASCII encoding error: ordinal not in range(128)
a='(???)(\d{3})'

Garth

From thp at cs.ucr.edu  Fri Sep 14 13:39:14 2001
From: thp at cs.ucr.edu (thp at cs.ucr.edu)
Date: Fri, 14 Sep 2001 17:39:14 +0000 (UTC)
Subject: Proposed PEP for a Conditional Expression
References:  <3BA13A10.8080108@visionart.com>
Message-ID: <9ntfc2$347$1@glue.ucr.edu>

Pete Shinners  wrote:
:>>  if  else 
:> 
:> But that appears to NOT scan like English.
:> "one if by land two if by sea"

: num_rings = 1 if enemy.onland() else 2

: not the most graceful english, heh. and i suppose
: it works if they are nested..

: num_rings = 1 if onland() else 2 if onsea() else 3

To fully reflect the "one if by land, two if by sea" construct of
English, we need to adopt the implicit "else None" idea.  Then

   1 if by_land() else 2 if by_sea()

means

   1 if by_land() else 2 if by_sea() else None

which is what the corresponding english means.

Tom Payne

From kdahlhaus at yahoo.com  Fri Sep 14 09:32:53 2001
From: kdahlhaus at yahoo.com (Kevin Dahlhausen)
Date: 14 Sep 2001 06:32:53 -0700
Subject: Python parsers that parse Java?
References: 
Message-ID: <283adf56.0109140532.24a76e08@posting.google.com>

Thanks, but I think there was a misunderstanding.  I want to parse a
java file with a python module, not to execute it, but to reformat and
add some member functions (maybe javadoc too), then spit the java
source back out.

The end goal is to do things like add get/setters from Vim based on a
list of attibutes.

BTW - as of tonight I'll be away from the net for a week or so, so I
won't be replying to anything.

From rnd at onego.ru  Tue Sep  4 13:48:13 2001
From: rnd at onego.ru (Roman Suzi)
Date: Tue, 4 Sep 2001 21:48:13 +0400 (MSD)
Subject: Question regarding commenting code
In-Reply-To: <682EFA0F37A1D511868700B0D0D1AB7A31BBDD@ISTECH4>
Message-ID: 

On Tue, 4 Sep 2001, Andrew Gould wrote:

>When adding comments to scripts, can I insert lines of comments inside a
>loop block?  For example:
>
>for n in a_list:
># separate values using spaces as delimiters
>	a_line = string.split(n)
># get the first value
>	a_value = a_line[0]
># print the first value
>	print a_value

This is not good.

Look at

http://www.python.org/doc/essays/styleguide.html

IIRC, it has a discussion of good comment style.

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Tuesday, September 04, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "Useless Invention: Fine glass-crystal castanets." _/

From johngrayson at home.com  Tue Sep  4 12:25:03 2001
From: johngrayson at home.com (johngrayson at home.com)
Date: Tue, 04 Sep 2001 16:25:03 -0000
Subject: python GUI without windowhandle
Message-ID: <9n2v8v+5v6l@eGroups.com>

If you're using Tkinter, then set the overrideredirect flag...

e.g.

    shell = Tkinter.Toplevel(root)
      .......
    shell.overrideredirect(1)
      .......

  John

From timr at probo.com  Wed Sep 19 01:54:06 2001
From: timr at probo.com (Tim Roberts)
Date: Tue, 18 Sep 2001 22:54:06 -0700
Subject: How to sort a list?  NOT a newbie question.
References: <9o4i4h$2ql@ascc.artsci.wustl.edu>
Message-ID: <4jcgqtsvc9dc7or96alisr6rhcv776qhd1@4ax.com>

mjbarber at ascc.artsci.wustl.edu (Michael James Barber) wrote:

>All in Python 2.1.1:
>
>>>> l1 = [1, '1j', [1,'1j']]
>>>> l1.sort()
>>>> print l1
>[1, [1, '1j'], '1j']
>
>>>> l2 = [1, 1j, [1,'1j']]
>>>> l2.sort()
>Traceback (most recent call last):
>  File "", line 1, in ?
>TypeError: cannot compare complex numbers using <, <=, >, >=
>
>
>This came up in the context of building the coefficients of polynomials 
>from a list of roots.  If complex roots occur in complex conjugate pairs, 
>then the resulting coefficients must be real, so I decided to cast the 
>coefficients to floats in this case.  A straightforward test is to take 
>the complex conjugate of each element of the list, then sort both lists 
>and see if they are the same.  As is clear from the above, that definitely 
>didn't work!  

You can make this work if you can answer a couple of simple questions.  

Which is greater:  3 or 3j?

Put these numbers in order:   3+0j  1+1j  1+2j  2+1j  2+2j   1+0j  0+3j
--
- Tim Roberts, timr at probo.com
  Providenza & Boekelheide, Inc.

From peter at engcorp.com  Fri Sep 28 23:28:52 2001
From: peter at engcorp.com (Peter Hansen)
Date: Fri, 28 Sep 2001 23:28:52 -0400
Subject: return command in a function.
References:  <9oudgb0vnk@enews2.newsguy.com> <9ov418$gs8$1@neon.noos.net>  
Message-ID: <3BB53FF4.764BA8C6@engcorp.com>

Duncan Booth wrote:
> 
> My rule of thumb for using return is that it is alright at or near the top
> of a function, and it is alright at or near the bottom of the function, and
> anywhere else the function is too long and should be split up anyway.

It's always nice to see a clear definition of something one 
has been doing instinctively without a clue why and without
even realizing (until now) that one has been doing it! :-)

Thanks...

-- 
----------------------
Peter Hansen, P.Eng.
peter at engcorp.com

From timhoffman at cams.wa.gov.au  Tue Sep  4 03:53:15 2001
From: timhoffman at cams.wa.gov.au (Tim)
Date: 4 Sep 2001 00:53:15 -0700
Subject: Strangeness with basic math
Message-ID: <1f3e18d3.0109032353.422b97ed@posting.google.com>

Hi

I have been racking my brains trying to RTFM to explain the following

bash-2.03$ python
Python 2.1 (#1, Jul  3 2001, 10:26:19) 
[GCC 2.95.2 19991024 (release)] on sunos5
Type "copyright", "credits" or "license" for more information.
>>> 1923.23 + 17023.34
18946.57
>>> 1923.23 - 17023.34
-15100.110000000001
>>> print 1923.23 - 17023.34
-15100.11
>>> 

Why when I do 1923.23 - 17023.34 am I getting -15100.110000000001
on NT I get the same thing. Under Python 1.5.2 I get the same and result as 
the print 1923.23 - 17023.34 (ie -15100.11)

Regards

Tim

From vesselinpeev at hotmail.com  Sun Sep 16 09:17:08 2001
From: vesselinpeev at hotmail.com (Vesselin Peev)
Date: Sun, 16 Sep 2001 16:17:08 +0300
Subject: Python errors messages in Windows
Message-ID: 

Dear Colleagues,

Does anyone know about a straightforward way of capturing the Python error 
messages in a Windows application embedding Python? That is, is there are 
version of PyErr_Print not using stdout?

Thank you in advance for your consideration.

_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp

From rnd at onego.ru  Fri Sep 14 15:52:02 2001
From: rnd at onego.ru (Roman Suzi)
Date: Fri, 14 Sep 2001 23:52:02 +0400 (MSD)
Subject: What's wrong with my script?
In-Reply-To: <9nti6o$g96$06$1@news.t-online.com>
Message-ID: 

On Fri, 14 Sep 2001, Michael Landmann wrote:

>Hi, I wrote this script and saved it as index.cgi, but it doesn't work.

Oh, yes, have you done

chmod a+x index.cgi

?

Sincerely yours, Roman Suzi
-- 
_/ Russia _/ Karelia _/ Petrozavodsk _/ rnd at onego.ru _/
_/ Friday, September 14, 2001 _/ Powered by Linux RedHat 6.2 _/
_/ "URA Redneck if you own a homemade fur coat." _/

From peter at engcorp.com  Thu Sep 20 09:15:41 2001
From: peter at engcorp.com (Peter Hansen)
Date: Thu, 20 Sep 2001 09:15:41 -0400
Subject: bsddb3 vs zodb
References: <3BA9A72A.1D5A6067@yahoo.com>
Message-ID: <3BA9EBFD.3F7ABFFA@engcorp.com>

vincent delft wrote:
> 
> does any one as analyze the pro and cons (functionalities, performances,
> ...) between Berkley DB3 (bsddb3) and ZODB ?

Isn't DB3 a relational database?  Since ZODB is clearly not, 
we're going to end up just comparing the "pros and cons" of
relational versus object-oriented databases, I think.

In any case, you should specify what your requirements are
before asking for such a comparison.  Without an idea what
the context is (what is your particular application area?)
the answers will be largely meaningless.

-- 
----------------------
Peter Hansen, P.Eng.
peter at engcorp.com

From unknown at lee-morgan.net  Fri Sep 28 00:18:02 2001
From: unknown at lee-morgan.net (Lee Morgan)
Date: Fri, 28 Sep 2001 04:18:02 GMT
Subject: Why so few Python jobs?
References: <9oltnk$vv3$1@nntp9.atl.mindspring.net> 
Message-ID: 

"Warren Postma"  writes:

> > Any ideas on why so few Python jobs are available?
> 
> In my job, I use Python, but it is because I know Python and felt it was
> the best tool for the job.   But seldom is it the "defining" characteristic
> of a position. In particular, my job calls for C/C++ skills.  I have ported
> python to embedded system platforms we use, and so my job is more entitled
> "Embedded C/C++ Developer" than "Python Developer".
> 

My position is similar, with python being a good 'glue' language, you're often
gluing!

-- 
Lee Morgan

From double_letter at room33.com  Thu Sep  6 00:01:08 2001
From: double_letter at room33.com (A.A)
Date: Thu, 06 Sep 2001 08:01:08 +0400
Subject: Python Install-Installed Python 2 on top of python 1.5
Message-ID: <3B96F504.1416D109@room33.com>

Hello,

I installed an rpm of Python 2.1.1, by right-clicking on it, and
clicking upgrade. But my python1.5 installation still exists. And If I
try to uninstallpython 1.5 from the RPM Manager, it raises an error
saying, dependency problems with so-and-so programs.

IS there a way to unistall Python 1.5 cleanly ??

Thanks,

Best Regards,

Ahsan

From phd at phd.pp.ru  Mon Sep  3 04:41:17 2001
From: phd at phd.pp.ru (Oleg Broytmann)
Date: Mon, 3 Sep 2001 12:41:17 +0400 (MSD)
Subject: Something like Perl's -c flag?
In-Reply-To: <9mrnod$p4k$1@tyfon.itea.ntnu.no>
Message-ID: 

Hi!

On Sun, 2 Sep 2001, Magnus Lie Hetland wrote:
MLH> "Oleg Broytmann"  wrote in message
MLH> news:mailman.999326826.29300.python-list at python.org...
MLH> > On 31 Aug 2001, Mark Atwood wrote:
MLH> > MA> Does the Python interpreter have anything like Perl's -c flag, which
MLH> > MA> does a static syntax and sanity check without actually running the
MLH> > MA> script?
MLH> >
MLH> >    Just compile the script. Like this:
MLH> >
MLH> > import sys
MLH> > from py_compile import compile
MLH> >
MLH> > if len(sys.argv) <= 1:
MLH> >    sys.exit(1)
MLH> >
MLH> > for file in sys.argv[1:]:
MLH> >    compile(file)
MLH>
MLH> You could also use pythonc, of course.

   What is "pythonc"? The only pythonc I know is PythonC - current CPython
implementation.

Oleg.
----
     Oleg Broytmann            http://phd.pp.ru/            phd at phd.pp.ru
           Programmers don't die, they just GOSUB without RETURN.

From phd at phd.pp.ru  Wed Sep 26 15:36:26 2001
From: phd at phd.pp.ru (Oleg Broytmann)
Date: Wed, 26 Sep 2001 23:36:26 +0400
Subject: pyc files on 2.0 and 2.1 compatible?
In-Reply-To: <3bb3f5ef.1023489@news.newsguy.com>; from ransen_spam_me_not@nemo.it on Wed, Sep 26, 2001 at 04:29:06PM +0000
References: <3bb3f5ef.1023489@news.newsguy.com>
Message-ID: <20010926233626.C16757@phd.pp.ru>

On Wed, Sep 26, 2001 at 04:29:06PM +0000, Owen F. Ransen wrote:
> Are compiled Python files compatible between version?
> Upwards? Backwards? 

   No, they are not.

Oleg.
---- 
     Oleg Broytmann            http://phd.pp.ru/            phd at phd.pp.ru
           Programmers don't die, they just GOSUB without RETURN.

From howard at eegsoftware.com  Wed Sep  5 01:57:04 2001
From: howard at eegsoftware.com (Howard Lightstone)
Date: Wed, 05 Sep 2001 05:57:04 GMT
Subject: python.exe/Tkinter hang on exit
Message-ID: <3B95BE7C.F4C7482F@eegsoftware.com>

About 1 out of 3 times I run my python.exe apps that use Tkinter windows
(Windows98SE), the application becomes a zombie if I close the app using
the x-box to kill the Tkinter window.  If I remember to do it (which
seems to be tough lately), a Ctrl-C in the dos box seems to ALWAYS kill
the app.

It seems the application is hanging on OLESCELOCKMUTEX during
termination, thus leaving a zombie task (which...typically... means I
cannot shut Windows down gracefully, if such a thing were possible).

I am assuming that some win32 thingey is not being called by the Tkinter
task temination logic,  BUT,  using pythonw.exe, termination ALWAYS
works correctly.  (I am using Python 2.0)

Any clues?  I haven't tried to take apart my apps and see which imports
do it
(but Pmw looks like just a wrapper) .

Thanks
Howard

From not.this at seebelow.org  Fri Sep 28 17:21:53 2001
From: not.this at seebelow.org (Grant Griffin)
Date: 28 Sep 2001 14:21:53 -0700
Subject: Why so few Python jobs?
References: <9oltnk$vv3$1@nntp9.atl.mindspring.net> <3BB4DB87.8600869E@ccvcorp.com>
Message-ID: <9p2plh025sm@drn.newsguy.com>

In article <3BB4DB87.8600869E at ccvcorp.com>, Jeff says...
>tszeto wrote:
>
>>
>> Any ideas on why so few Python jobs are available?
>>
>
>My take, in addition to the many good reasons already mentioned, is that
>Python is so easy to learn, that when it *is* appropriate to use, it's usually
>simpler for the existing staff to learn Python as well (or for an otherwise
>qualified recruit to be taught Python), than to specifically hunt for someone
>already skilled in Python.
>
>Of course, if the company has a need for a *very* skilled Python programmer,
>then hiring specifically for that skill becomes reasonable.

Yeah.  But I hope I never have to maintain the code written by somebody like
that--doesn't the world have too many maps and lambdas as it is ?

Although Python is quite easy to learn (for a C/C++ programmer), truly
"mastering" it takes awhile.  I've been writing Python for two years now, and
there still are many fine points I haven't mastered yet.

When I started with it (with version 1.5.2), Python already had several fairly
advanced constructs that the garden-variety programmer doesn't really need or
use.  But to make things worse, new constructs are coming along at a rate faster
than tiny-brained folks like me can master them.  For example, I haven't yet
taken the time and energy to really figure out what weak references are: I just
studied them long enough to determine that I can easily live withouth them.

Of course, since Python long ago had all the constructs you really need, and
since new syntactic sugar is specifically disallowed, the only category for new
constructs to fall into is "advanced".  (I resisted the temptation to use
"obscure" here ).  In fact, the only two things added since Python 1.5.2
that are genuinely useful to me are augmented assignments and string methods.

But I guess all this is a compliment to Python in a way: a really good toy is
one whose mastery seems attainable, yet isn't.  (There's gotta be _some_ reason
people pay good money just to play golf .)

But apart from the "advanced", we have the "Pythonic".  This is perhaps of more
use, but seems to come only from time and experience.

somebody-oughtta-write-a-book--ly y'rs,

=g2

_____________________________________________________________________

Grant R. Griffin                                       g2 at dspguru.com
Publisher of dspGuru                           http://www.dspguru.com
Iowegian International Corporation            http://www.iowegian.com

From aleax at aleax.it  Mon Sep 17 09:12:22 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 17 Sep 2001 15:12:22 +0200
Subject: How to parse XHTML with xml.parsers.xmlproc?
References: <873d5mo5cz.fsf@zazu.vip.fi> <9o4bqs0251k@enews4.newsguy.com> <87r8t6m6bj.fsf@zazu.vip.fi>
Message-ID: <9o4srq03r@enews4.newsguy.com>

"Paavo Hartikainen"  wrote in message
news:87r8t6m6bj.fsf at zazu.vip.fi...
    ...
> I was under the impression that well-formedness is also defined
> somehow in DTD.

Well... there *IS* that abomination which is called CDATA,
which can indeed make well formedness dependent on DTD's,
for an otherwise constant "stream of characters".  *Shudder*.

I think you need that in XHTML for such things as 

No I do not have a clue what the message is and I'm sure I am not the
only one who doesn't.

Here is the message I intended for dongkui (and to be seen by the list):

It has come to me pretty obvious that you are a windows user.  Yet I
have no idea on your abilities or knowledge about other operating
systems, and therefore I will not make judgements.  But in case you
didn't know there ARE other people out there using different systems. 
Now even though we use many different systems and os's and all we can
still communicate.  You want to know why, well because we ALL use the
standard world wide, text.  Yes plain text, so no-one needs to worry
about a new virus being spread, so everyone even thoose sitting in front
of some unix system using only command line e-mail can understand you,
no text doesn't have flashy graffics and neon lights and so on, but when
e-mail started it wasn't intended for that, it was intended to connect
people through a common source of communication that all with a simple
computer and connection to the internet could access.  Now Microsoft has
changed the direction into a community where only thoose who want their
software can communicate with thoose that do, but you still have a
choice you can communicate with the standard of the rest of the world,
or just keep on using whatever Microsoft spoon-feeds you.  If you really
want your questions to be viewed by as many of the intelligent minds on
this list as possible please use the standard that is not only the
standard for a few, but the standard for all.

					Dan

-- 
John 11:25 "Jesus said to her, I am the resurrection and the life. He who
believes in me will live, even though he dies;" --
Daniel Hammond-[ x = 'fleltltl at ltlrlaldlelrlsldlaltlal.lclolml'
emailaddress = string.replace(x, 'l', '')]

From tripie at cpan.org  Sun Sep  2 21:16:42 2001
From: tripie at cpan.org (Tomas Styblo)
Date: 2 Sep 2001 18:16:42 -0700
Subject: [ANN] htmltmpl and easydoc
Message-ID: 

htmltmpl is a templating engine for separation of code and HTML,
targeted mainly at web applications. It's similar and compatible with
HTML::Template, which is an templating engine that is very popular in
Perl world.

easydoc is an example application similar to Javadoc using htmltmpl to
generate XHTML-Strict compliant documentation from docstrings embedded
in Python source files.

Webpage of the project is at: http://htmltmpl.sourceforge.net/

Example output of easydoc (API documentation of htmltmpl itself) is
available at: http://htmltmpl.sourceforge.net/python-api.html

This is first public announcement. More detailed information follows.

----

The purpose of the templating engine is to provide web application
developers, who need to separate program code and design (HTML code)
of their web application projects, with a templating tool that can be
easily used by cooperating webdesigners who have no programming
skills.

Templating language provided by the engine is inspired by Perl
templating module HTML::Template. Templates created for HTML::Template
can be used with this engine.

The engine is currently available for Python. Java version is coming
soon. The Python package includes easydoc, a module which uses the
templating engine to generate HTML documentation from docstrings
embedded in source files of Python modules.

The primary goal of the templating engine is to keep things simple for
a webdesigner who creates the templates. Therefore, neither Python nor
Java code can be used in the templates. Instead, the templating engine
provides its own simple templating language that supports basic
programming operations like for example loops, conditionals and
substitution of variables. These operations are controlled from within
the templates by statements that look like HTML tags and integrate
nicely with regular HTML code.

The secondary goal is good performance. High speed template processing
is necessary when the engine is used by web applications.

I am aware that other templating solutions for Python and Java exist.
But none of them is similar to HTML::Template. I love its enforcement
of strict separation of code and HTML and the style and syntax of its
template language. I find it much more cleaner and maintainable than
the other solutions. Also, I need to move some projects from Perl to
Python and Java and I want to reuse my old HTML::Template templates.
These are the reasons why I created the templating engine.

----
Tomas Styblo, tripie at cpan.org
"too cynic for love, too ugly for sex"

From drek at smashpow.net  Sun Sep  9 17:17:24 2001
From: drek at smashpow.net (Agent Drek)
Date: Sun, 9 Sep 2001 17:17:24 -0400 (EDT)
Subject: os.stat() ?
Message-ID: 

Am I wrong in thinking that this should return a value that chmod(1)
would expect?

$ touch myfile
$ ls -l myfile
-rw-r--r--  1 drek  pow  0 Sep  9 17:07 myfile

import os, stat
print os.stat('myfile')[stat.ST_MODE] & 0777

I get '420' from os.stat

python2.1.1 on FreeBSD

I'm looking for the best way to get a list of the full attributes of
a file.

thanks,

--
   Derek Marshall

Smash and Pow Inc > 'digital plumber'
http://www.smashpow.net

From tim.one at home.com  Sat Sep  1 22:27:49 2001
From: tim.one at home.com (Tim Peters)
Date: Sat, 1 Sep 2001 22:27:49 -0400
Subject: Stackless Python and Python 2.x
In-Reply-To: <7xd75azev0.fsf@ruckus.brouhaha.com>
Message-ID: 

[Paul Rubin]
> How is it possible to implement resumable generators without using
> coroutines, continuations, or something equivalent?

Have you read the PEP?

    http://python.sourceforge.net/peps/pep-0255.html

This flavor of generator is formally a semi-coroutine, and it's the
asymmetry that makes impementation easier; a PEP 255 generator can suspend
only to the routine that invoked it, and only to the point of invocation,
which implies that nothing more than the generator's local state needs to be
preserved between resumptions.  In Python terms, since execution frames were
already heap-allocated, it?s not much of an exaggeration to say that the
primary trick to implementing generators was simply to refrain from
decrementing a frame?s refcount upon yielding.

BTW, the book ?Advanced Programming Language Design? is available online:

    http://cseng.aw.com/book/related/0,3833,0805311912+20,00.html

and chapter 2 shows in excruciatingly detail how to implement CLU iterators
(also semi-coroutines) using almost-standard C, abusing the C stack via
setjmp/longjmp tricks.

From tim.one at home.com  Mon Sep 10 18:37:37 2001
From: tim.one at home.com (Tim Peters)
Date: Mon, 10 Sep 2001 18:37:37 -0400
Subject: installation fails ?
In-Reply-To: <9njbdj$ml$1@fstgss02.tu-graz.ac.at>
Message-ID: 

[Armin Samide]
> I'have downloaded the Python 2.1.1 source code package and wanted to
> buildit on Windows with the Microsoft Visual C Compiler but a few
> headers are missing, as there are: zlib.h, xmlparse.h, db.h, tcl.h
> Are these headers included somewhere else or what else is wrong ?

If you want to build the non-core 3rd-party components, you need to follow
the instructions for obtaining and installing them too.  The instructions
are in PCbuild\readme.txt.

From richard at bizarsoftware.com.au  Tue Sep 18 00:50:12 2001
From: richard at bizarsoftware.com.au (Richard Jones)
Date: Tue, 18 Sep 2001 14:50:12 +1000
Subject: Problems with pythonw.exe/embdedding Zope terminating
In-Reply-To: <0109181438521Y.01597@ike>
References: <0109181438521Y.01597@ike>
Message-ID: <0109181450121Z.01597@ike>

On Tuesday 18 September 2001 14:38, Richard Jones wrote:
> On Win2000 & 98, running:
> > python z2s.py

Python version 2.1.1

   Richard

From mats at laplaza.org  Sun Sep  2 11:32:32 2001
From: mats at laplaza.org (Mats Wichmann)
Date: Sun, 02 Sep 2001 15:32:32 GMT
Subject: Freezing Jython PY scripts
References: 
Message-ID: <3b924e9e.187040339@news.laplaza.org>

On Sun, 02 Sep 2001 04:43:17 GMT, "Maan Hamze" 
wrote:

:I need to be able to create a Jython compiled JAR file that can be run on a
:PC without Jython on it.
:With Test.py I am compiling with
:  jythonc -j Test.py
:to create Test.jar
:I have the classpath set correctly to '.' and jython.jar is included in the
:classpath through jythonc.  And jython is using jave.exe from the Sun JRE.
:However when I run Test.jar:
:java -jar Test.jar
:I am getting the error message due to a class not found:
:org.python.core.PyObject
:what am I doing wrong?

There's a freeze utility in the Jython tools directory that may help
with the question you started this message with. I have no experience
with it.  As a tip, if you head over to the jython-users mailing list,
you'll find lots of folks willing and able to help, and I know this
topic comes up from time to time.  You can sign up by following the
Jython project page at jython.sourceforge.net.
Mats Wichmann

From James_Althoff at i2.com  Thu Sep 20 13:58:07 2001
From: James_Althoff at i2.com (James_Althoff at i2.com)
Date: Thu, 20 Sep 2001 10:58:07 -0700
Subject: Proposed PEP for a Conditional Expression
Message-ID: 

Tom Payne wrote:
>To me,
>
>          count = 1 if by_land() else
>                  2 if by_sea()  else
>                  0
>
>is clearer than
>
>         if by_land():
>                 count = 1
>         elif by_sea():
>                 count = 2
>         else:
>                 count = 0

On the other hand, it's hard to make the case that the latter is *unclear*.
And it's already there, just waiting to be used. ;-)

Jim

From emile at fenx.com  Tue Sep 18 15:05:07 2001
From: emile at fenx.com (Emile van Sebille)
Date: Tue, 18 Sep 2001 12:05:07 -0700
Subject: voodoo: modifying class methods a posteriori
References: 
Message-ID: <9o8664$bhp7t$1@ID-11957.news.dfncis.de>

class A's f can be invoked from within new method g().  Does this help?

class A:
  def f(self):
    print 'hello'
def g(self):
  print 'bye'
  A.f(self)
a = A()
a.f()
import new
a.f = new.instancemethod(g, a, A)
print a.f()

--

Emile van Sebille
emile at fenx.com

---------
 wrote in message
news:mailman.1000836080.3205.python-list at python.org...
> Hi,
>
> This is a problem that has bugged me for a while, now. (Related topic
> might be "function closure", which I don't understand much.)
>
> What follows is pure Python voodoo. But when voodoo is used properly,
> it does wonders. :)
>
> Say, you have a class "A" with method "f(self)" (which potentially
> could be the constructor __init__() or destructor __del__(), by the
> way.)
>
> Instance-bound methods can be overriden easily. (I am not interested
> in derived subclass, see the reason a bit later.)
>
> class A:
>   def f(self):
>     print 'hello'
> def g(self):
>   print 'bye'
> a = A()
> a.f()
> import new
> a.f = new.instancemethod(g, a, A)
> a.f()
>
> The class-bound method f() can be overriden, easily, too:
>
> class A:
>   def f(self):
>     print 'Hello'
> def g(self):
>   print 'Bye'
> a = A()
> a.f()
> A.f.im_func.func_code = g.func_code
> a.f()
>
> Now, all that is nice. BUT, usually, when you override a method, you
> probably want to do just a bit more than what the old method was
> doing. Say, you may only want to add a print statement when the
> method is called, or you may want to insert a statement to the
> constructor/destructor so object instances can automatically
> register/deregister to a particular event handler.
>
> When you have many subclasses derived from subclasses of other
> classes, especially when you don't have access to the source code for
> one reason or another, or when you don't want to or you can't modify
> the source code of the superclass, is there a way of inserting
> statements into the class methods?
>
> In derived class, what you would do is something like:
>
> class A:
>   def f(self):
>     print 'Hello'
> class AA(A):
>   def f(self):
>     print 'before saying Hello'
>     A.f(self)
>     print 'after saying Hello'
> a = AA()
> a.f()
>
> Notice you are able to insert statements before and after the base
> class method call.
>
> Is there a way of doing the same thing without subclassing?
>
> =============
>
> hmm.... I think I just answered myself, I'll post it to the mailing
> list anyway:
>
> class A:
>   def f(self):
>     print 'Hello'
> def g(self):
>     print 'before saying Hello'
>     self.f_old()
>     print 'after saying Hello'
> a = A()
> a.f()
> import new
> A.f_old = A.f
> A.f = new.instancemethod(g, None, A)
> a.f()
>
> =====================
>
> Wow! It's fun! I wonder why people are still using Java. :)
>
> Hung Jung
>
>
>

From hungjunglu at yahoo.com  Wed Sep 19 08:49:24 2001
From: hungjunglu at yahoo.com (Hung Jung Lu)
Date: 19 Sep 2001 05:49:24 -0700
Subject: voodoo: modifying class methods a posteriori
References:  
Message-ID: <8ef9bea6.0109190449.475c713@posting.google.com>

slinkp23 at yahoo.com (Paul Winkler) wrote in message news:...
> This is exactly what the Decorator design pattern is for.  

I don't think so. :)

(1) In real-life programming, what I have explained is a real need. In
an actual commercial software development, you typically have many
people collaborating, and you use third-party modules. Everything is
moving at the same time, and some modules are not under your control.
So, very often, it's best practice not to touch other people's codes.
Now, the other people have a whole package of many modules and classes
and subclasses, and you want to modify the behavior of a superclass,
at some branch of the complicated class hierarchy structure. What you
have described is nothing but a more elaborate way of class
derivation, and it does not help, because you'll have to copy and
re-do the whole class hierarchy tree, when all what you wanted was to
modify one single method in the superclass. In other words, you cannot
modify the behavior of existing objects in your approach: you are only
introducing new classes, new objects. In C++ and in Java, you simply
cannot modify the behavior of a superclass's methods, no way Jose,
that's part of the corporate security concerns inherent to those
languages. In Python, you can. You can insert hooks almost at will.

(2) Beware of the word "pattern". It's fad, I know. But "pattern
programming" is nothing but a rephrasing of "give me an example,
please". I've seen fads come and gone, and "pattern" seems to be one
of them. :)

regards,

Hung Jung

From marknenadov at winningteam.com  Fri Sep 28 09:10:15 2001
From: marknenadov at winningteam.com (Mark Nenadov)
Date: Fri, 28 Sep 2001 13:10:15 GMT
Subject: Does there exist a Python-to-Perl translator ?
References: <3BB2D226.3C260A2C@Spam.Please>  <3BB31597.96BFE8B7@Spam.Please> <9p1ccu$pfr$1@neon.noos.net>
Message-ID: <20010928.092734.1351797369.1132@d150-171-215.home.cgocable.net>

In article <9p1ccu$pfr$1 at neon.noos.net>, "Boyd Roberts"
 wrote:

> "Weet Vanniks"  a ?crit dans le message news:
> 3BB31597.96BFE8B7 at Spam.Please...
>> You don't get my point. Managers do want to see Perl code. What I want
>> is benefit from the productivity of Python, get something working and
>> then satisfy my manageer with a Perl solution.
> you're thinking about it the wrong way.  you'd be better off _training_
> your manager to get a grip.  usually works for me :)

Hmm... for some reason this manager likes messy code :)

From aleax at aleax.it  Tue Sep 11 05:47:30 2001
From: aleax at aleax.it (Alex Martelli)
Date: Tue, 11 Sep 2001 11:47:30 +0200
Subject: Proposed PEP for a Conditional Expression
References:  <6qvgire4bk.fsf@abnoba.intevation.de> <9nidrm01j7q@enews1.newsguy.com> <9nk4t8$4qq$1@glue.ucr.edu>
Message-ID: <9nkmjj01rha@enews3.newsguy.com>

 wrote in message news:9nk4t8$4qq$1 at glue.ucr.edu...
> Alex Martelli  wrote:
> : "Bernhard Herzog"  wrote in message
> : news:6qvgire4bk.fsf at abnoba.intevation.de...
> :     ...
> :> >          What's wrong with just satisfying people?
> :>
> :> Lots of people asking for it is a reason to write the PEP, but not
> :> necessarily a reason to actually adopt the PEP.
>
> : Seconded on both scores.  Specifically, adding to Python all the
> : features that "lots of people" ask for would ensure Python's
> : transformation into a huge, bloated language. *THIS* is "what's
> : wrong with just satisfying people", as here rhetorically asked:
> : trying to make everybody happy will ensure nobody's happy:-).
>
> The above non-sequitur applies equally well to every proposal that
> "lots of people ask for".

Exactly, except it's not a non-sequitur.  "Just satisfying people"
(by meeting every popular feature request) is NO way to design a
language (or, as it happens, any other large software system:-).

Alex

From jkn at nicorp.f9.co.uk  Thu Sep 27 10:48:14 2001
From: jkn at nicorp.f9.co.uk (Jon Nicoll)
Date: 27 Sep 2001 07:48:14 -0700
Subject: scanf style parsing
References: <3BB16A50.BAE082FE@cygnus-software.com> 
Message-ID: <8351bb33.0109270648.75af3371@posting.google.com>

trivial followup: isn't it ... amazing ... the number of programs
which still have this kind of output?

> > 
> > smtpmail.exe - 0 error(s), 0 warning(s)
                          ___           ___

    jon N

From jtdubs at eos.ncsu.edu  Sat Sep  8 21:38:04 2001
From: jtdubs at eos.ncsu.edu (Justin Dubs)
Date: Sat, 8 Sep 2001 21:38:04 -0400
Subject: large class hierarchies in python
Message-ID: <9neh5p$gi2$1@uni00nw.unity.ncsu.edu>

Hey guys,

I'm new to python, as of last week.  I know several other OO langauges
though.  Anyway, I am having trouble getting a hierarchy of "modules" to
behave as I would like them to.  I guess I have several questions, or maybe
just one long one.

I love python's syntax and functionality.  I'm not sure, however, if I am
the least bit pleased with the way it deals with "modules".  I probably just
don't understand what I'm doing.  I'm trying to pretty much do Java style
package hierarchies with python modules and I'm not sure if it is
possible/appropriate.

I want the directory structure to be the module (package?) structure of the
program.  And I want each class to exist in a file of the same name.  I
haven't yet gotten this concept to mesh well with the python module/import
paradigm.  For example:

/
/agent
/agent/Agent.py
/agent/Environment.py
/agent/grid
/agent/grid/GridAgent.py
/agent/grid/GridEnvironment.py

Here, GridAgent and GridEnvironment inherit from Agent and Environment,
respectively.  I assume each directory will need a __init__.py file, but I
really don't understand what to put in it to have it behave the way I'd
like.  Any suggestions?

Also, as a maybe simpler question:

Is this entire method of programming just not going to work out with Python?
Is Python not suitable for this type of problem?  If not, what languages do
you know of that are syntactially similar to Python and WOULD be
appropriate?

Thanks a lot guys,

Justin Dubs

From m.1.robinson at herts.ac.uk  Mon Sep  3 12:06:04 2001
From: m.1.robinson at herts.ac.uk (Mark Robinson)
Date: Mon, 03 Sep 2001 17:06:04 +0100
Subject: namespaces getting confusing
Message-ID: <3B93AA6C.10209@herts.ac.uk>

can anyone explain why I get the following attribute error. I know it is 
something to do with me misusing namespaces and imports but I dunno what.

%Motif.py
import param

def readSeq(filename)
	#bla bla bla

#some other def's

#################

%param.py
import os, Motif

#various variable initialised
seq = Motif.readSeq

###############
%Camel.py
import os, Motif, param #and others

#other non relevant code

###########

I get the following error:

Traceback (most recent call last):
   File "D:\blobby\param.py", line 1, in ?
     import os, Motif
   File "D:\blobby\Motif.py", line 1, in ?
     import string, math, pickle, param
   File "D:\blobby\param.py", line 30, in ?
     seq = Motif.readSeq(filename)
AttributeError: 'Motif' module has no attribute 'readSeq'

From peter at engcorp.com  Fri Sep  7 10:08:54 2001
From: peter at engcorp.com (Peter Hansen)
Date: Fri, 07 Sep 2001 10:08:54 -0400
Subject: newbie: cannot import name error
References: 
Message-ID: <3B98D4F6.445C1525@engcorp.com>

"rjberman at NOSPAMrodessaNOSPAM.com" wrote:
> 
> import distutils, os, sys, stat
> from distutils.core import setup, Extension
> 
> The error I get is:
> 
> 131> python test1.py
> 
> Traceback (most recent call last):
>   File "test1.py", line 7, in ?
>     from distutils.core import setup, Extension
> ImportError: cannot import name Extension

I don't know anything about distutils, but I can do
'from distutils import extension'.  Was that what you 
needed?  Python is case-sensitive.

> Can someone help me? I can't believe that on my second encounter
> with Python I've already been stumped! This is not a good first
> impression. Any help would be appreciated or even pointers to help!

On the other hand, you're trying to do something I've _never_ 
needed to do yet, after almost two years with Python.  Any time
(to date) I've needed to install an extension, I've been okay
with just copying it to the python/lib folder, or with adding
an entry to a .pth file (see the docs in site.py) to point it
to the folder in which I keep my own extensions.

By the way, why are you running (a) an old version, and (b) 
an _alpha_ version!

-- 
----------------------
Peter Hansen, P.Eng.
peter at engcorp.com

From boud at rempt.xs4all.nl  Thu Sep 13 14:31:24 2001
From: boud at rempt.xs4all.nl (Boudewijn Rempt)
Date: 13 Sep 2001 18:31:24 GMT
Subject: [PyQt] Confused by this class hierachie ...
References: <9nqgdb$h2i$1@news.netcologne.de>
Message-ID: <9nqu1s$6hl$1@news1.xs4all.nl>

Well, without some actual code it's difficult to tell exactly what your
problem is. What I mostly do is create the dialogs in the constructor of
my main window class - that makes it available everywhere. You create
the dialog with the main window instance as parent, and that means you
can get at the main window from the dialog with self.parent().

You can take a look at http://stage.linuxports.com/pyqt/x1771.htm or
http://stage.linuxports.com/pyqt/c3816.htm - the first is about the
standard dialogs PyQt offers, the second about creating real, complex
dialogs.  

If those chapters don't clear away your confusion, please tell
me - then I can adapt the text and make it clearer!

--

Boudewijn Rempt  | http://www.valdyas.org 

From aleax at aleax.it  Mon Sep  3 07:02:54 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 3 Sep 2001 13:02:54 +0200
Subject: typechecks: just say no! (was Re: Determining Types)
References: 
Message-ID: <9mvo0u04o8@enews2.newsguy.com>

"Adonis Vargas"  wrote in message
news:fe9k7.1835$ix.446807 at newsrump.sjc.telocity.net...
> how am i able to determine types of variables? i have come up with the

Be aware that, MOST times you THINK you need to typecheck, you
really *don't*.  Type-checks break the wonderful signature based
polymorphism that is the key to so much of Python's power and
simplicity.  Check out the Cookbook recipe:
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52291
for a way to avoid type-checking (in favour of signature
checking) even when you might think it's indispensable.

That much being said, the built-in function isinstance is the
least painfully horrible way to do typechecking anyway:

def sometypechecking(anobject):
    if isinstance(anobject, type('')):
        print "it's a string"
    elif isinstance(anobject, type(0)):
        print "it's an int"
    elif isinstance(anobject, type(0.0)):
        print "it's a float"
    else:
        print "it's something else"

You can do it in other ways, such as testing if
    type(anobject) is type('')
and so on, but there is really no advantage to those other
ways -- they just damage polymorphic behavior even worse
than isinstance-based checks do (no observable difference
in Python 2.1, but in Python 2.2 it will be possible to
inherit from built-in types: such inheriting objects will
pass an isinstance-based check, but fail a type-is-type
based check, which only checks *identity of types* and NOT
subclassing-relationships).

To summarize: don't type check.  If you think you must,
use "accurate look-before-you-leap" instead.  If you STILL
think you must, use isinstance.  *AND* lobby for the
"protocol-adaptation PEP", the "Object Adaptation" PEP 246,
http://python.sourceforge.net/peps/pep-0246.html, which, if
it's ever adopted in Python, would offer "one obviously right
way" to handle most situations in which people tend to
erroneously think type-checks are the best solution.

Alex

From aleaxit at yahoo.com  Sat Sep  8 16:32:29 2001
From: aleaxit at yahoo.com (Alex Martelli)
Date: Sat, 8 Sep 2001 22:32:29 +0200
Subject: troubles with list.append()
References: <4f374853.0109081133.74969472@posting.google.com>
Message-ID: <9ndv8502ion@enews2.newsguy.com>

Joe wrote:

> I'm having some difficulties with appending
> a list to a list.  The code works how I want
> it to if used within the the interpreter.

You're probably doing something slightly different in that case.

> patch_listing.append(patch)
> 
> Printing patch_listing after the while loop
> shows it filled with all of the same entries.

Right, because you ARE appending references that are all to the same 
object, patch.  Append *copies* of that obiect instead, e.g.:

        patch_listing.append(patch[:])

or, after an import copy,

        patch_listing.append(copy.copy(patch))

Python never implicitly takes a copy -- you have to request one when you 
want one.  That doesn't matter for immutable objects, but lists are 
mutable, so there IS a difference between having a copy (a "snapshot" taken 
at some point, and fixed unless and until you choose to mutate it) and a 
reference to the original (since the "original" object keeps changing).

Alex

From eppstein at ics.uci.edu  Thu Sep  6 16:16:50 2001
From: eppstein at ics.uci.edu (David Eppstein)
Date: Thu, 06 Sep 2001 13:16:50 -0700
Subject: Image file comments and/or EXIF-info
References: <9n8lau$66q2g$1@ID-59332.news.dfncis.de>
Message-ID: 

In article <9n8lau$66q2g$1 at ID-59332.news.dfncis.de>,
 "Bror Johansson"  wrote:

> Are there any modules that can be used for reading/writing comments and/or
> EXIF-info from/to imagefiles (capable of) holding such info?
> 
> PythonMagick seems to be competent with comments. Is PythonMagick compatible
> to Python 2.1?

exifdump by Thierry Bousch can at least read EXIF data, I haven't looked 
for code that will write it.

http://topo.math.u-psud.fr/~bousch/exifdump.py
-- 
David Eppstein       UC Irvine Dept. of Information & Computer Science
eppstein at ics.uci.edu http://www.ics.uci.edu/~eppstein/

From cpr at emsoftware.com  Thu Sep  6 10:14:59 2001
From: cpr at emsoftware.com (Chris Ryland)
Date: 6 Sep 2001 07:14:59 -0700
Subject: dictionary and __getattr__
References:  
Message-ID: <8827e15d.0109060614.59036c18@posting.google.com>

Michael Abbott  wrote in message news:...
> Harald Kirsch  wrote in 
> news:yv28zfsr6e8.fsf at lionsp093.lion-ag.de:
> 
> > 
> > 
> > Wouldn't it be nice if this would work:
> > 
> >   d = {'x': 1}
> >   print d.x
> > 
> > i.e. every entry in a dictionary is also an attribute of the
> > dictionary itself. 
> > 
> > Is there a class wrapper for that somewhere available?
> 
> I expect this would work:
> 
>     	class Wrap:
>     	    def __init__(self, dict):
>     	        self.__dict__.update(dict)
> 
>     	d = {'x': 1}
>     	dd = Wrap(d)
>     	print dd.x
> 
> Of course, this may not be exactly what you want, because dd won't follow 
> updates to d.

Hey, won't the new 2.2 support for extending built-in classes such as
dictionaries make this both easy and complete?

--Chris Ryland, Em Software

From daniel.dittmar at sap.com  Thu Sep  6 07:29:49 2001
From: daniel.dittmar at sap.com (Daniel Dittmar)
Date: Thu, 6 Sep 2001 13:29:49 +0200
Subject: dictionary and __getattr__
References: 
Message-ID: <9n7mna$e4m$1@news1.wdf.sap-ag.de>

> Wouldn't it be nice if this would work:
>
>  d = {'x': 1}
>  print d.x
>
>i.e. every entry in a dictionary is also an attribute of the
>dictionary itself.

class AttributeDict (UserDict):
    __getattr__ = UserDict.__getitem__

Daniel

From tim at vegeta.ath.cx  Tue Sep 25 01:22:26 2001
From: tim at vegeta.ath.cx (Tim Hammerquist)
Date: Tue, 25 Sep 2001 05:22:26 GMT
Subject: Why so few Python jobs?
References:   <3BB00345.4F1237B5@engcorp.com>
Message-ID: 

Me parece que Peter Hansen  dijo:
> Tim Hammerquist wrote:
> >
> > A good argument.  One of my favorite things about Python is that I never
> > run the risk of having to maintain code like this:
> > 
> > sub myfunc {
> > do_stuff();
> > do_some_more_stuff();
> > $screw = with @some_variables;
> > for $item (@some_variables){
> > do_stuff();
> > and_some_more(); }
> > do_a_bit_more();
> > blah;
> > }
> 
> What's so bad about this?!

Heh.  Good thing you didn't ask me when I had to maintain this code. I
would've bitten your head off...so to speak...I hope.  

> It's just indentation with a tabsize of zero... ;-)
> 
> -is-that-really--perl?-ly yr's,

It parses, yes.  But C code of the same format would parse as well.
However, no instructor I've ever had would have accepted it.  They'd
have said, "Rewrite the code structure, turn it back in, and accept a
10% deduction from the final score for late work.

No Perl module from CPAN has this form, nor any code posted to c.l.p.m
(other than from newbies).  Larry Wall suggests a 4-wide tabs with open
and closing braces in corresponding columns.  The above code would
result in:

sub myfunc
{
    do_stuff();
    do_some_more_stuff();
    $screw = with @some_variables;
    for $item (@some_variables)
    {
        do_stuff();
        and_some_more();
    }
    do_a_bit_more();
    blah;
}

(at which point the Python side of my brain kicks in and says, "Well,
there's two perfectly good screen lines wasted with one character...")

-ly yr's,
Tim

-- 
I'm already not yet convinced.
    -- Larry Wall

From quinn at yak.ugcs.caltech.edu  Mon Sep 24 10:20:45 2001
From: quinn at yak.ugcs.caltech.edu (Quinn Dunkan)
Date: 24 Sep 2001 09:20:45 -0500
Subject: Dr. Dobb's Python-URL! - weekly Python news and links (Sep 24)
Message-ID: 

QOTW:  "Is Python fit for multi-tiered apps?--Yes, especially as an
alternative to Java!"  The context for this was the observation that
Python appears to do a bunch of Three (and four!) Letter Acronyms just
as well as Java (the original poster actually wanted to know about
multi-tierd apps, which sounds much more rugged and industrial).  AMK
mentions an article about such an app, which well documents the design
of a mid-sized python project (it also mentions his Cervantic web
application framework, Quixote).
    http://groups.google.com/groups?threadm=9o7lvv%24170%2401%241%40news.t-online.com
    http://www.amk.ca/python/writing/mx-architecture/

   The Ottawa Python Authors Group goes live at
       http://www.opag.ca 

    Sam is apparently having trouble with instance and class
    attributes.  It turns out the problem was a bug in other
    code (importing the wrong module), but in the meantime
    there's a lot of discussion about scoping, binding, and
    Alex's new "Borg" pattern:
        http://groups.google.com/groups?threadm=ii7k7yvqi87.fsf%40central.sun.com

    The Law of Demeter says that objects shouldn't have (or need)
    deep knowledge of the structure of other objects.  If that
    was unclear or you don't agree or you think "well, that's
    obvious, but not very specific", the following thread explains
    things much better:
        http://groups.google.com/groups?threadm=slrn9qf4r5.p9.slinkp23%40roaddog.armsnet

    Tim demonstrates what fun can be had with Python 2.2 generators
    when finding permutations.  It's also a good example of a recursive
    generator:
        http://groups.google.com/groups?threadm=mailman.1000707871.18101.python-list%40python.org

    For a journalistic treatment of generators and other 2.2 goodies,
    see
        http://www.unixreview.com/articles/2001/0109/0109h/0109h.htm

    Chris wants to bundle python modules similar to Java's JARs.  It's
    possible with the __import__ hook, as Installer and py2exe
    demonstrate:
        http://groups.google.com/groups?threadm=rsHrsJAP5op7Ew7L%40jessikat.fsnet.co.uk

========================================================================

Everything you want is probably one or two clicks away in these pages:

    Python.org's Python Language Website is the traditional
    center of Pythonia
        http://www.python.org
    Notice especially the master FAQ
        http://www.python.org/doc/FAQ.html

    PythonWare complements the digest you're reading with the
    daily python url
         http://www.pythonware.com/daily  

    comp.lang.python.announce announces new Python software.  Be
    sure to scan this newly-revitalized newsgroup at least weekly.
        http://groups.google.com/groups?oi=djq&as_ugroup=comp.lang.python.announce

    Michael Hudson continues Andrew Kuchling's marvelous tradition
    of summarizing action on the python-dev mailing list once every
    other week.
        http://starship.python.net/crew/mwh/summaries/
        http://www.amk.ca/python/dev

    The Vaults of Parnassus ambitiously collect Python resources
        http://www.vex.net/~x/parnassus/   

    Much of Python's real work takes place on Special-Interest Group
    mailing lists
        http://www.python.org/sigs/

    The Python Software Foundation has replaced the Python Consortium
    as an independent nexus of activity
        http://www.python.org/psf/

    Cetus does much of the same
        http://www.cetus-links.de/oo_python.html

    Python FAQTS
        http://python.faqts.com/

    The old Python "To-Do List" now lives principally in a
    SourceForge reincarnation.
	http://sourceforge.net/tracker/?atid=355470&group_id=5470&func=browse
	http://python.sourceforge.net/peps/pep-0042.html

    Python Journal is at work on its second issue
        http://www.pythonjournal.com

    Links2Go is a new semi-automated link collection; it's impressive
    what AI can generate
        http://www.links2go.com/search?search=python

    Archive probing tricks of the trade:
        http://groups.google.com/groups?oi=djq&as_ugroup=comp.lang.python&num=100
        http://groups.google.com/groups?meta=site%3Dgroups%26group%3Dcomp.lang.python.*

Previous - (U)se the (R)esource, (L)uke! - messages are listed here:
  http://www.ddj.com/topics/pythonurl/         
  http://purl.org/thecliff/python/url.html (dormant)
or
  http://groups.google.com/groups?oi=djq&as_q=+Python-URL!&as_ugroup=comp.lang.python

Suggestions/corrections for next week's posting are always welcome.
[http://www.egroups.com/list/python-url-leads/ is hibernating.  Just
e-mail us ideas directly.]

To receive a new issue of this posting in e-mail each Monday morning,
ask  to subscribe.  Mention "Python-URL!".

-- The Python-URL! Team--

Dr. Dobb's Journal (http://www.ddj.com) is pleased to participate in and
sponsor the "Python-URL!" project.
-- 

Cameron Laird 
Business:  http://www.Phaseit.net
Personal:  http://starbase.neosoft.com/~claird/home.html

From ignacio at openservices.net  Fri Sep 14 19:42:33 2001
From: ignacio at openservices.net (Ignacio Vazquez-Abrams)
Date: Fri, 14 Sep 2001 19:42:33 -0400 (EDT)
Subject: What's wrong with my script?
In-Reply-To: <9nu2t0$of3$00$1@news.t-online.com>
Message-ID: 

On Sat, 15 Sep 2001, Michael Landmann wrote:

> > > > print "Content-type: text/html\n\n" # add this line here
> > >
> > > Doesn't work
> >
> > You need to give us more information than "Doesn't work" if you want to
> > get it working.  Is it executable?  Is it in a place where the Web
> > server can get at it?  Is the Web server configured to execute CGI
> > scripts for that area?
>
> Error 500
>
> The Server is ready to work with CGI, PHP3, PHP4, Python, Perl

Once you have tried the other change that has been suggested, you have to set
the Options directive for the directory that the CGI program is in to have
+ExecCGI.

-- 
Ignacio Vazquez-Abrams  

From drek at smashpow.net  Wed Sep  5 18:57:06 2001
From: drek at smashpow.net (Agent Drek)
Date: Wed, 5 Sep 2001 18:57:06 -0400 (EDT)
Subject: debugging a c module?
Message-ID: 

I've made a loadable module to speed up a portion of a python program
that I'm working on. Once in awhile (1 time out of 10) I get a core
dump on exit from the interpreter "Abort (core dumped)". I'm pretty sure
that this is because I've screwed up a reference count somewhere in the
module.

How do I go about debugging this? I'm using Python-2.1.1 on FreeBSD4.x.

Recompile python and the module with debugging? gdb?

This small problem aside, the C/API is great to work with! There are
lots of useful docs explaining how to write the modules I just haven't
found any that talk about the debugging process.

cheers,

--
   Derek Marshall

Smash and Pow Inc > 'digital plumber'
http://www.smashpow.net

From ht_xu at hotrmail.com  Mon Sep 10 16:44:22 2001
From: ht_xu at hotrmail.com (Henry)
Date: Mon, 10 Sep 2001 15:44:22 -0500
Subject: How to know it is a list?
Message-ID: 

Hi guys,
  I have a newbie question. How do check if a variable is a list?

Thanks in advance,
Henry

From dlharris at mail.usyd.edu.au  Wed Sep 12 12:08:58 2001
From: dlharris at mail.usyd.edu.au (Dave Harrison)
Date: Thu, 13 Sep 2001 02:08:58 +1000
Subject: waste of life
In-Reply-To: <01091216462900.03157@phoenix>; from heikowu@ceosg.de on Wed, Sep 12, 2001 at 04:46:29PM +0200
References: <01091216462900.03157@phoenix>
Message-ID: <20010913020858.A6804@isetroc.com>

I'll second that.  We can only hope that one day such senseless acts of indiscriminate violence will just be a memory.

Dave

Thus spake Heiko Wundram (heikowu at ceosg.de):

> Hello to all fellow list members!
> 
> As I have not heard a single word about it on the list so far, I thought that 
> I might as well take the initiative and express my grievance at seeing the 
> pictures that were broadcast for all day today (and yesterday too) about the 
> suicide bombings (or whatever you might call it) of the two twin towers in 
> New York and also the Pentagon in Washington.
> 
> Let us all mourn the great loss of lives (only comparable to a natural 
> catastrophe) that occured in just one hour due to such a cowardly act of 
> terrorism against civilians. Let us hope that all those innocent people who 
> died during these acts of crime are now in a better place.
> 
> And let us think greatfully of all rescue workers, the medical staff of the 
> hospitals and all those individuals who came out to help or donate blood in 
> New York and Washington, and of course of all those who endangered or lost 
> their lives trying to help the people who were caught up in the debris of the 
> buildings.
> 
> On a last note to myself, although the need for revenge that many Americans 
> feel at the moment is justifiedly huge, I sincerely hope that this act of war 
> of an as yet unknown agressor against America will not lead to a scenario 
> that was discussed in a late night show yesterday evening on German TV:
> 
> "World War 3".
> 
> -- 
> Yours sincerely,
> 
> 	Heiko Wundram
> 
> -- 
> http://mail.python.org/mailman/listinfo/python-list

From nas at python.ca  Thu Sep  6 11:17:09 2001
From: nas at python.ca (Neil Schemenauer)
Date: Thu, 6 Sep 2001 08:17:09 -0700
Subject: Performance of list comprehensions vs. map
In-Reply-To: <9n7n6u02leo@enews1.newsguy.com>; from aleax@aleax.it on Thu, Sep 06, 2001 at 01:38:07PM +0200
References: <3B966B1C.120D0AF6@home.net>  <9n7n6u02leo@enews1.newsguy.com>
Message-ID: <20010906081708.A18176@glacier.arctrix.com>

Alex Martelli wrote:
> I think one key issue is: map requires its sequence arguments to
> support len()

It won't in 2.2.  Any object that supports the iteration protocol will
do (thanks to Tim).  

  Neil

From beppu at binq.org  Thu Sep  6 04:55:57 2001
From: beppu at binq.org (John Beppu)
Date: Thu, 6 Sep 2001 01:55:57 -0700
Subject: lexical closures and python
In-Reply-To: 
References: <20010905225609.A18903@BinQ.org> 
Message-ID: <20010906015557.B18903@BinQ.org>

[  date  ] 2001/09/06 | Thursday | 02:45 AM
[ author ] Ignacio Vazquez-Abrams  

> (which, BTW, to begin to understand I had to go through LISP 101,
> Beginning LISP, LISP for Dummies, LISP for Idiots, and 
> LISP for Complete F*cking Morons... ;) )
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
My favorite!  ;-)

> Other than lambdas, you can also mention the map(), reduce(), and filter()
> functions, which as I may have heard somewhere do FP-like operations.

Those functions would definitely be good to mention.

> Also, I gotta ask: How the hell does JavaScript support them?
                     ^^^^^^^^^^^^
hehe.

Surprisingly, it's not very contrived.  Here's a simple example
you can save as an HTML file and try out in a JavaScript-enabled
browser.

         js closure example 

Notice how grande and pequeno remember the value of current, but
also notice that they each remember their own current variable.
Because current is lexically bound to a new closure each time
sequence_iterator() is invoked, grande and pequeno do not
interfere with each other.

Interesting, no?

From aleax at aleax.it  Mon Sep  3 11:10:24 2001
From: aleax at aleax.it (Alex Martelli)
Date: Mon, 3 Sep 2001 17:10:24 +0200
Subject: Use of GMPY
References: <9n03in$c6o$1@pegasus.tiscalinet.it>
Message-ID: <9n06h001orh@enews1.newsguy.com>

"Patrick"  wrote in message
news:9n03in$c6o$1 at pegasus.tiscalinet.it...
> Hi,
>
> I'm trying to use GMPY module but it does not seem to work !? When I
import
> the GMPY module into Python IDE, I get an error message telling me that
one
> DLL is missing, but does not give the name of this missing DLL.

I had last updated the file you downloaded:
http://prdownloads.sourceforge.net/gmpy/gmpy-win32-binary-09.zip
on Jan 24, and Python 2.1 was not released then -- only Python 2.0.

So, the windows-binary version of GMPY could only run with Python 2.0.

I've just uploaded a release that runs with Python 2.1 instead:
http://prdownloads.sourceforge.net/gmpy/gmpy-win32-binary-09a21.zip

No other changes, except rebuilding it with Python 2.1.  I've also
made a 09a21 release of the sources package, taking the occasion to
fix the doctest (which relied on the error message format from
Python 2.0 -- now it expects the message format of 2.1:-) and add
the setes.py (to be used just like setup.py:-) to build the
"pysymbolicext" sample C-extension to gmpy kindly supplied by Pearu
back in January.

> Can someone help ?

Who better than the author/maintainer, i.e., me?-)  (P.S.: I
wonder why you didn't mail me directly -- isn't my email
in evidence somewhere on the project page...?  Gotta fix
that, if so...!).

> * I use a 2.1 AtiveState version of python 'as it comes from thes
> ActiveState' site,
>
> * I have downloaded the 0.9 version of GMPY and copied the GMPY.PYD and
> PYSYMBOLICEXT.PYD files in my \Python21\lib directory...

Thanks for the details, which immediately enabled me to pinpoint
the problem -- and thanks for your interest in GMPY, too.

Alex

From rnd at onego.ru  Wed Sep 19 08:10:35 2001
From: rnd at onego.ru (Roman Suzi)
Date: Wed, 19 Sep 2001 16:10:35 +0400 (MSD)
Subject: Using MySQLdb Newbie
In-Reply-To: <01091912543507.01260@jordan.utopia.net>
Message-ID: 

On Wed, 19 Sep 2001, Jordan Elver wrote:

> Sorry. More details coming.
> I'm using Linux Mandrake 8.0 with Python version 2.0.
> I downloaded the tarball uncompressed it and read the README. It says to run 
> python setup.py build then python setup.py install. But, when i try either of 
> these they both give the same error?

Install newer Distutils.

Probably, that MySQLdb distro was prepared for newer Distutils. I had no
problem on RedHat 6.2 With Python 2.1 apart from MySQLdb (and PyGreSQL)
both core-dumped Python until I recompiled it with pth (GNU threads)
instead of pthreads.

Sincerely yours, Roman A.Suzi
-- 
 - Petrozavodsk - Karelia - Russia - mailto:rnd at onego.ru -

From heikowu at ceosg.de  Thu Sep  6 07:07:47 2001
From: heikowu at ceosg.de (Heiko Wundram)
Date: Thu, 6 Sep 2001 13:07:47 +0200
Subject: dictionary and __getattr__
In-Reply-To: 
References: 
Message-ID: <01090612512400.00324@phoenix>

On Thursday 06 September 2001 11:54, you wrote:
> Wouldn't it be nice if this would work:
>
>   d = {'x': 1}
>   print d.x
>
> i.e. every entry in a dictionary is also an attribute of the
> dictionary itself.
>
> Is there a class wrapper for that somewhere available?

# Works with Python 2.2a2.

from __future__ import generators

class AttributeDictionary:

    def __init__(self):
        self.dict = {}
        self.default = None

    def __getitem__(self, key):
        return self.dict[key]

    def __setitem__(self, key, value):
        self.dict[key] = value

    def __delitem__(self, key):
        del self.dict[key]

    def __getattr__(self, key):
        if not key in self.dict:
            raise AttributeError
        return self.dict[key]

    def __setattr__(self, key, value):
        self.dict[key] = value

    def __delattr__(self, key):
        del self.dict[key]

    def get(self, key, default=None):
        try:
            return self[key]
        except:
            if default == None:
                return self.default
            else:
                return default

    def setdefault(self, default):
        self.default = default

    def has_key(self, key):
        try:
            self[key]
            return 1
        except:
            return 0

    def __iter__(self):
        for i in self.dict:
            yield i
        raise StopIteration

>
>   Harald Kirsch

Works (almost like a dictionary). I've left out the more exotic dictionary 
functions like update, etc, for demonstration purposes only. The rest works 
as is.

-- 
Yours sincerely,

	Heiko Wundram

From jbranthoover at yahoo.com.NOSPAM  Mon Sep 17 16:39:18 2001
From: jbranthoover at yahoo.com.NOSPAM (John Branthoover)
Date: Mon, 17 Sep 2001 20:39:18 GMT
Subject: Newbie: How to download a JPG file from the internet....?
Message-ID: 

Hello All,
    Can anyone tell me how to download an image from a web site?
An example:
 that is located at www.somewhere.org

    I have already found the urllib module and have used the urlopen
function to create a string from a web page,  but I don't know how to
proceed from here.  I can isolate the string -  , but then what?  I would like to eventually write
it to a file on my local drive.  Any information will be greatly
appreciated.  Thank you for your time.

From fredp at mygale.org.nospam  Mon Sep  3 04:37:36 2001
From: fredp at mygale.org.nospam (Fred Pacquier)
Date: 3 Sep 2001 08:37:36 GMT
Subject: Formatting question : printing numbers with thousands separators ?
References:  <5699ebda.0108310933.1646ac@posting.google.com>
Message-ID: 

juneaftn at orgio.net (June Kim) said :

> * and the most(or more or less) obfuscated way as a one-liner is:
> 
> def sep(s):  return
> re.sub(r"([-+]?\d{1,3}(\.\d*)?)(?=(\d{3})*(\.|$))",r",\1",s)[1:]

tanzer at swing.co.at (Christian Tanzer) said :

> How about:
>>>> import re
>>>> sep_1000_pat = re.compile("(\d{1,3}) (?= (?: \d\d\d)+ (?! \d) )",
>>>> re.X) sep_1000_pat.sub(r"\g<1>,", "2342342342344567") 
> '2,342,342,342,344,567'
> Short, but then you need Friedl's masterpiece on regular expression to
> understand it...

Ouch. Didn't know you could also write Perl in Python... :-))))))

-- 
YAFAP : http://www.multimania.com/fredp/

From aleax at aleax.it  Wed Sep 12 08:26:04 2001
From: aleax at aleax.it (Alex Martelli)
Date: Wed, 12 Sep 2001 14:26:04 +0200
Subject: question with embeding python in C
References: <3B9EFC71.A90FD092@club-internet.fr>
Message-ID: <9nnk8s02igh@enews1.newsguy.com>

"LAMY Bertrand"  wrote in message
news:3B9EFC71.A90FD092 at club-internet.fr...
> here is my question :
> when I create a Python object in a C function with PyObject_New and the
> C function return that object to python, do I have to Py_INCREF the
> object before ?

No, PyObject_New returns an object with one reference to it
already, and you can just pass that reference on.

> In the help examples, for all 'new' functions that create in C an
> instance of a new type, the object is returned without Py_INCREF. that
> works.

Right.

> the 2 bugs were corrected by Py_INCREF the object before returning it.

So you have some OTHER refcount-related bug in these cases -- you
have one decref somewhere that you shouldn't have, so adding one
incref balances things out.  But you should really find out where
the stray decref comes from.  Since they're C objects of a type
you control, why not just add some printf calls in their destructors
to let you know the instant the dtor is running, and run the
simplest failing-case Python script you can imagine with tracing
turned on -- that should let you help narrow things down (you
can also use a C-level debugger to put a breakpoint in the
destructor and check the stack trace for more information, if
that's feasible on your specific platform).

Alex

From sholden at holdenweb.com  Fri Sep 28 21:35:15 2001
From: sholden at holdenweb.com (Steve Holden)
Date: Fri, 28 Sep 2001 21:35:15 -0400
Subject: Repost: execfile() confusion
References: <9p2iuk$1au@gap.cco.caltech.edu>
Message-ID: <%v9t7.1727$mg1.21543@atlpnn01.usenetserver.com>

"Nathaniel Gray"  wrote in
message news:9p2iuk$1au at gap.cco.caltech.edu...
> Sorry for the repost but I didn't get any responses.
> So once again, execfile() isn't doing what I thought it did.
>
Please accept my aplogies, I was getting on with my life under the confident
assumption that the many fine brains who read this newsgroup would assist
you with lightning speed. Since they've *all* let you down (shame on you,
you know who you are), I'll have to resort to my standard strategy of
providing an incorrect explanation and then letting the rest of c.l.py tell
you exactly why I am wrong.

> For example, with these two files:
>
> ##############
> #### test2.py ####
> x = 'spam'
>
> #### test.py ####
> def doit():
>     execfile( 'test2.py' ) # x = 'spam'
>     print x
>
> doit()
> ##############
>
> I get the following when I run 'python test.py':
> """
> Traceback (most recent call last):
>   File "test.py", line 5, in ?
>     doit()
>   File "test.py", line 3, in doit
>     print x
> NameError: global name 'x' is not defined
> """
>
> I though that execfile was supposed to act on the locals() of the scope
> from which it was called.  I also tried adding x=None to the top of doit()
> but execfile still doesn't change its value to 'spam'.  Can somebody
please
> explain what's going on?
>
You have made a mistaken assumption, mistrusting the documentation when in
fact everything is perfectly explicable as documented. Your assumption is
that inside doit() the interpreter will check for x as a local before it
checks for x as a global.

Unfortunately this is NOT the case, and the error mesage explicitly informs
you of that fact. When it compiles a function, the interpreter statically
examines the code for assignments to (or more accurately, bindings of)
names. If any are found then it compiles code to access those names as
locals. The situation is slightly complicated if you have imported
nested_ascopes from future, as it then statically examines each lexically
surrounding function before defaulting to module global, but that need not
concern us here.

The error message is explicitly telling you that the global x has no value.
So, Watson, the only theory that fits the facts is that execfile() has
behaved exactly as its documentation describes, and bound the value 'spam'
to the name x in the local scope of function doit().

Because there are no bindings to x in doit() to be found by static
examination, however, the interpreter has decided that x will be in the
module's global scope, and compiled bytecode which attempts to access it
form there. Which, you will now realise, is why the error message complains
that global x has not been defined.

So now, Watson, if you will be good enough to hand me my violin and my
cocaine, you can return to your scratchings, and I shall return to mine.
Kindly insert a print of the dir() function inside doit(), and return only
if no x is to be found therein.

never-seen-a-case-for-a-local-statement-before-ly y'rs  - steve
--
http://www.holdenweb.com/

From sheila at spamcop.net  Mon Sep 10 18:34:13 2001
From: sheila at spamcop.net (Sheila King)
Date: Mon, 10 Sep 2001 22:34:13 GMT
Subject: smtp.sendmail read receipt?
References:  
Message-ID: <9nim4k.3vvcfe1.1@kserver.org>

On 11 Sep 2001 00:44:27 +0300, Erno Kuusela 
wrote in comp.lang.python in article :

:i don't know of any mail user agents that support rfc 2298 though (not
:that i know that many).

Well, some of them must. When I occasionally send out e-mail in Pegasus
(a Windows client) and mark the receipt notification options, I do get
receipts for some of the people I send to (not all of them, of course).

--
Sheila King
http://www.thinkspot.net/sheila/
http://www.k12groups.org/

From richard at bizarsoftware.com.au  Fri Sep 21 04:02:03 2001
From: richard at bizarsoftware.com.au (Richard Jones)
Date: Fri, 21 Sep 2001 18:02:03 +1000
Subject: "shell-commands" and python!
In-Reply-To: <9oeqks$8t0$1@zingo.tninet.se>
References: <9oeqks$8t0$1@zingo.tninet.se>
Message-ID: <01092118020305.32742@ike>

On Saturday 22 September 2001 02:40, Mike S wrote:
> how do I execute "shellcommands" in python???
> do I need to use the os module and the system command?
>
> Is there any simplier way to do it??

Yes,

  http://www.python.org/doc/current/lib/module-commands.html

Described as "8.18 commands -- Utilities for running commands" in the table 
of contents of the library reference.

   Richard

From nobody at nexus.sourcedns.com  Sun Sep 23 00:37:35 2001
From: nobody at nexus.sourcedns.com (nobody at nexus.sourcedns.com)
Date: Sat, 22 Sep 2001 22:37:35 -0600 (GMT)
Subject: !!Burn DVD using your CDRW!!
Message-ID: 

Hi!

Yes it sounds too good to be true but it IS true!
You can burn your very own DVD with a regular CD burner! 
You can make BIG money selling this incredible software too!
This is NOT a scheme or hype! It's the most advanced technology!

To burn:

http://www.dvdcopy.tv

To sell:

http://resell.dvdcopy.tv

*****************************************
This is a one-time mailing only for
those who are interested. No removal is
required. We applogize if this email
disturbed you.
*****************************************

From roy at panix.com  Sun Sep  2 18:55:55 2001
From: roy at panix.com (Roy Smith)
Date: Sun, 02 Sep 2001 18:55:55 -0400
Subject: calling __init__ more than once?
Message-ID: 

I've got a file parsing class which in which I call a single parser object 
repeatedly to parse additional files.  Something like:

   p = myParser()
   stuff1 = p.parse (fileName1)
   stuff2 = p.parse (fileName2)

Is there any reason why my parse method couldn't call __init__() to reset 
things back to the start state?  It feels kind of creepy, but I don't see 
any reason why it should be a problem.  Is there something I'm missing 
here, or is it really OK to call __init__() again?

From boyd at insultant.net  Mon Sep 24 03:18:34 2001
From: boyd at insultant.net (Boyd Roberts)
Date: Mon, 24 Sep 2001 09:18:34 +0200
Subject: time.timezone gives strange results on cygwin
References: 
Message-ID: <9ommtq$7mm$1@neon.noos.net>

"Andy Todd"  a ?crit dans le message news:
Xns91268760EEA31andytoddspamfreeyaho at 203.109.250.24...
> time.timezone is returning an incorrect value on cygwin python.
> From the documentation;
>
> """
> timezone
>      The offset of the local (non-DST) timezone, in seconds west of UTC
>      (i.e. negative in most of Western Europe, positive in the US, zero in
>      the UK).
> """

seems like they followed the unix stupidity.

rfc822 Date: headers OTOH get it right.

From tim at vegeta.ath.cx  Thu Sep 20 00:55:18 2001
From: tim at vegeta.ath.cx (Tim Hammerquist)
Date: Thu, 20 Sep 2001 04:55:18 GMT
Subject: Best book on Python?
References: <9oasom$pit$1@plutonium.btinternet.com>
Message-ID: 

Me parece que Ian Bolton  dijo:
[ snip ]
> I am based in the UK and have read about a quarter of a borrowed copy of
> Programming Python 1st edition.  Now that I am back at uni and no longer
> have access to the other book, I am gonna have to buy one.  I've looked at
> Programming Python 2nd edition and it looks good, but is it the best one out
> for an beginner-intermediate programmer?  (My Python experience is limited
> to about 10 weeks worth of programming.)  Also, where's the cheapest place
> to get hold of PP2, or whatever you recommend?

Excellent learning text:
    Learning Python, Mark Lutz, ORA

Excellent reference:
    Python Essential Reference, Beazley?, New Riders (2nd Ed.
    recommended)

I wouldn't waste money on Prog. Python (ORA).  It's a diluted "Learning
Perl" that doesn't really do anything with Python except
Tkinter...unless this is really what you want.

HTH
-- 
Emacs is a nice OS - but it lacks a good text editor.
That's why I am using Vim.
    -- Anonymous

From dcinege at psychosis.com  Thu Sep  6 22:51:43 2001
From: dcinege at psychosis.com (David Cinege)
Date: Thu, 6 Sep 2001 22:51:43 -0400
Subject: how to run python script from Unix Shell?
In-Reply-To: 
References: 
Message-ID: 

On Thursday 06 September 2001 22:41, Ignacio Vazquez-Abrams wrote:
> On 6 Sep 2001, David wrote:
> > Hi there,
> >
> > Can you help to advise how to run python script from Unix Shell?
> > What I am doing is:
> > 1)chmod +x  script name
> > 2)put #!/usr/bin/python   at first line
> > 3)when I type the script name under Shell,
> > the message is:
> > bash: Script name command not found.
> >
> > Actually, it works if I type:
> > python "script name"
> >
> > But the problem is I want run it by typing "script name"
> >
> > Thanks for your help.
>
> You have to call it as follows:
>
>   ./