Mailman 3 January 2011 - Python-Dev

Re: [Python-Dev] [Python-checkins] r87815 - peps/trunk/pep-3333.txt
by Victor Stinner 07 Jan '11

07 Jan '11

Le vendredi 07 janvier 2011 à 16:39 +0100, phillip.eby a écrit : > Author: phillip.eby > Date: Fri Jan 7 16:39:27 2011 > New Revision: 87815 > > Log: > More bytes I/O fixes > > > Modified: > peps/trunk/pep-3333.txt > > Modified: peps/trunk/pep-3333.txt > ============================================================================== > --- peps/trunk/pep-3333.txt (original) > +++ peps/trunk/pep-3333.txt Fri Jan 7 16:39:27 2011 > @@ -310,9 +310,9 @@ > elif not headers_sent: > # Before the first output, send the stored headers > status, response_headers = headers_sent[:] = headers_set > - sys.stdout.write('Status: %s\r\n' % status) > + sys.stdout.buffer.write('Status: %s\r\n' % status) > for header in response_headers: > - sys.stdout.write('%s: %s\r\n' % header) > + sys.stdout.buffer.write('%s: %s\r\n' % header) > sys.stdout.write('\r\n') Are ('Status: %s\r\n' % status) and ('%s: %s\r\n' % header) byte strings or unicode strings? Victor

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Checking input range in time.asctime and time.ctime
by Alexander Belopolsky 07 Jan '11

07 Jan '11

There are several reports of bugs caused by the fact that the behavior of C functions asctime and ctime is undefined when they are asked to format time for more than 4-digit years: http://bugs.python.org/issue8013 http://bugs.python.org/issue6608 (closed) http://bugs.python.org/issue10563 (superseded by #8013) I have a patch ready at issue 8013 that adds a check for large values and causes time.asctime and time.ctime raise ValueError instead of producing system-dependent results or in some cases crashing or corrupting the python process. There is little dispute that python should not crash on invalid input, but I would like to ask for a second opinion on whether it would be better to produce some distinct 24-character string, say 'Mon Jan 1 00:00:00 *999', instead of raising an exception. Note that on some Windows systems, the current behavior is to produce '%c999' % (year // 1000 + ord('0')) for at least some large values of year. Linux asctime produces strings that are longer than 26 characters, but I don't think we should support this behavior because POSIX defines asctime() result as a 26 character string and Python manual defines time.asctime() result as a 24 character string. Producing longer timestamps is likely to break as many applications as accepting large years will fix. OSX asctime returns a NULL pointer for large years. My position is that raising an error is the right solution. This is consistent with year range supported by datetime. Another small issue that I would like to raise here is issue6608 patch resulting in time.asctime() accepting 0 as a valid entry at any position of the timetuple. This is consistent with the behavior of time.strftime(), but was overlooked when issue6608 was reviewed. I find the case for accepting say 0 month or 0 day in time.asctime() weaker than that for time.strftime() where month or day values may be ignored.

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Re: [Python-Dev] [Python-checkins] devguide: Strip out all generic svn instructions from the FAQ. It's not only
by Nick Coghlan 06 Jan '11

06 Jan '11

On Wed, Jan 5, 2011 at 5:55 AM, brett.cannon <python-checkins(a)python.org> wrote: > brett.cannon pushed 72a286c3452d to devguide: > > http://hg.python.org/devguide/rev/72a286c3452d > changeset: 13:72a286c3452d > user: Brett Cannon <brett(a)python.org> > date: Tue Jan 04 11:48:38 2011 -0800 > summary: > Strip out all generic svn instructions from the FAQ. It's not only > silly to duplicate instructions that can be found all over the > internet that are maintained by the creators of the tools under > discussion, but it's a maintenance burden that is unneeded. Your call as the author, but please reconsider this one. I've found it *hugely* convenient over the years to have these task oriented answers in the FAQ. The problem with the answers all over the internet is that I (or someone new to our source control tool) may not know enough to ask the right question, and hence those answers may as well not exist. Even if these FAQ answers don't always provide everything needed, they usually provide enough information to let me search for the full answers. Cheers, Nick. -- Nick Coghlan | ncoghlan(a)gmail.com | Brisbane, Australia

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Re: [Python-Dev] Implementing strftime Was: Checking input range in time.asctime and time.ctime
by Alexander Belopolsky 06 Jan '11

06 Jan '11

On Thu, Jan 6, 2011 at 11:30 AM, Eric Smith <eric(a)trueblade.com> wrote: .. > Is strftime really so complex that we shouldn't just write our own? I'd be > willing to do it. Over the years the platform strftime has caused any number > of problems. The last time I looked at it we already have to do some work > pre-parsing the format string and passing it off to platform strftime, so > it's not like it's not already a maintenance hassle. > This is the subject of issue 3173: http://bugs.python.org/issue3173 As far as I can tell, the main problem with implementing strftime is that it has to be locale aware and locale API is as inconsistent/buggy across platforms as strftime itself. > I understand strptime is probably more complex and there's some value to > having strptime/strftime coming from the same library. But I'd be willing to > look at it, too. strptime is already implemented (in pure python) by stdlib, but it piggybacks on strftime for locale information. See Lib/_strptime.py.

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Re: [Python-Dev] [Python-checkins] devguide: Start a doc on running and writing unit tests.
by Terry Reedy 06 Jan '11

06 Jan '11

> +The shortest, simplest way of running the test suite is:: > + > + ./python -m test Not on Windows. C:\Programs\Python32>./python -m test '.' is not recognized as an internal or external command, operable program or batch file. python -m test works (until it failed, separate issue). I would like to know, insofar as possible, how to run tests from the interpreter prompt (or IDLE simulation thereof) from whatmod import whatfunc; whatfunc() # ?? ditto for such remaining alternatives you give as can be made from prompt. Besides the convenience for Windows users (for whom the Command Prompt window is hidden away and possibly unknown), I think we should know if any tests are incompatible with interactive mode. --- Terry Jan Reedy

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Re: [Python-Dev] [Python-checkins] r87768 - in python/branches/py3k: Lib/socket.py Lib/test/test_socket.py Misc/NEWS
by Terry Reedy 05 Jan '11

05 Jan '11

> Issue #7995: When calling accept() on a socket with a timeout, the returned > socket is now always non-blocking, regardless of the operating system. Seems clear enough > + # Issue #7995: if no default timeout is set and the listening > + # socket had a (non-zero) timeout, force the new socket in blocking > + # mode to override platform-specific socket flags inheritance. Slightly confusing > + # Issue #7995: when calling accept() on a listening socket with a > + # timeout, the resulting socket should not be non-blocking. Seems to contradict the first. 'sould not be non-blocking' to me means 'should be blocking', as opposed to 'is now ... non-blocking'. Terry

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Re: [Python-Dev] [Python-checkins] devguide: Add a note about a possible starter project.
by Nick Coghlan 05 Jan '11

05 Jan '11

On Thu, Jan 6, 2011 at 8:11 AM, brett.cannon <python-checkins(a)python.org> wrote: > +.. todo:: > + See if tempfile or test.support has a context manager that creates and > + deletes a temp file so as to move off of test.support.TESTFN. Yeah, tempfile.TemporaryFile and friends all support the CM protocol. There's also the tempfile.TemporaryDirectory CM (as of 3.2). Cheers, Nick. -- Nick Coghlan | ncoghlan(a)gmail.com | Brisbane, Australia

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Re: [Python-Dev] [Python-checkins] devguide: Start a doc on running and writing unit tests.
by Terry Reedy 05 Jan '11

05 Jan '11

> +Running > +------- Is there a way to skip a particular test, such as one that crashes the test process? Terry

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Hello everyone
by yeswanth 05 Jan '11

05 Jan '11

Hello everyone, My name is Yeswanth . I am doing my third year Btech in Computer Science in India. My desire is to get into gsoc 2011 . I have been looking over the projects of last year to see where I would fit in. And I found python to be interesting, something I can contribute. I dont know if Python Software Foundation will apply for Gsoc this year, I just hope it will . So here I am , planning to make an entry in contributing to this open source project. I can just program in Python ,never contributed anything to it , atleast of now. So I have read the development links provided in the python.org site. Can anyone suggest me some areas where I can actually start with developing for this proje

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Possible optimization for LOAD_FAST ?
by Lukas Lueg 05 Jan '11

05 Jan '11

Consider the following code: def foobar(x): for i in range(5): x[i] = i The bytecode in python 2.7 is the following: 2 0 SETUP_LOOP 30 (to 33) 3 LOAD_GLOBAL 0 (range) 6 LOAD_CONST 1 (5) 9 CALL_FUNCTION 1 12 GET_ITER >> 13 FOR_ITER 16 (to 32) 16 STORE_FAST 1 (i) 3 19 LOAD_FAST 1 (i) 22 LOAD_FAST 0 (x) 25 LOAD_FAST 1 (i) 28 STORE_SUBSCR 29 JUMP_ABSOLUTE 13 >> 32 POP_BLOCK >> 33 LOAD_CONST 0 (None) 36 RETURN_VALUE Can't we optimize the LOAD_FAST in lines 19 and 25 to a single load and put the reference twice on the stack? There is no way that the reference of i might change in between the two lines. Also, the load_fast in lne 22 to reference x could be taken out of the loop as x will always point to the same object....

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