Mailman 3 March 2008 - Python-Dev

How best to handle test_errno?
by Brett Cannon March 13, 2008

March 13, 2008

I am going through my backlog of GHOP work and noticed that test_errno is essentially a no-op at the moment. I was wondering if anyone knew if there are any guaranteed values for the errno module? If not, the test current says that Linux has all the values; is that really true? -Brett

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Python 2.5.1 error when running cvs2svn [SEC=UNCLASSIFIED]
by James, Paul March 13, 2008

March 13, 2008

Hello python-dev, We are trying to run the cvs2svn utility and get an execution problem coming from Python. The version of Python we have installed on a solaris sparc10 machine is 2.5.1. The error trace is below, the error is at end in blue- Traceback (most recent call last): File "/usr/local/bin/cvs2svn", line 27, in <module> from cvs2svn_lib.main import main File "/usr/local/lib/python2.5/site-packages/cvs2svn_lib/main.py", line 31, in <module> from cvs2svn_lib.run_options import RunOptions File "/usr/local/lib/python2.5/site-packages/cvs2svn_lib/run_options.py", line 41, in <module> from cvs2svn_lib.svn_output_option import DumpfileOutputOption File "/usr/local/lib/python2.5/site-packages/cvs2svn_lib/svn_output_option.py ", line 42, in <module> from cvs2svn_lib.svn_repository_mirror import SVNRepositoryMirror File "/usr/local/lib/python2.5/site-packages/cvs2svn_lib/svn_repository_mirro r.py", line 34, in <module> from cvs2svn_lib.serializer import MarshalSerializer File "/usr/local/lib/python2.5/site-packages/cvs2svn_lib/serializer.py", line 24, in <module> import zlib ImportError: ld.so.1: python: fatal: relocation error: file /usr/local/lib/python2.5/lib-dynload/zlib.so: symbol inflateCopy: referenced symbol not found -The zlib.so file exisits on our machine at the specified path. We are using Python 2.5.1. If possible, could you provide advice on where the problem is occuring? Thanks, Paul James Paul.James(a)amsa.gov.au <mailto:Paul.James@amsa.gov.au> ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you are not the intended recipient, you are notified that any use or dissemination of this communication is prohibited. If you receive this transmission in error, please notify us immediately by telephone on +61 2 62795000 and delete all copies of this transmission together with any attachments. **********************************************************************

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Why .index() is not a method of all sequence types ?
by Joost Behrends March 13, 2008

March 13, 2008

Hello, hopefully this mailing list is the right address for the following. Since there is a huge gap in performance between tuple(cur.execute(...)) and list(cur.execute(...)) - i saw a factor in the magnitude of 50 once - the first has always to be chosen when sufficient. Even if that difference would be smaller - you also document the resulting sequence as read-only in your code. I also use deque( ... some generator ... ) frequently (And i think, that this should have more room in tutorials for beginners - some of them have no idea, what tuples are for). With such a tuple tp i tried 'ix = tp.index(...)' recently and was astonished to learn, that this doesn't work. Since we have '... in tp' for me it seems, that it should make very little difference in the interpreter's code, if .index() would be a method of any sequence, mutable or not. Such a small difference, that this minor change wouldn't deserve a PEP. Do i overlook something here ? Kind regards, Joost Behrends

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Python XML Validator
by Medhat Gayed March 12, 2008

March 12, 2008

I tested and tried a few XML validators but none of them is able to successfully validate a string of xml (not a file just a string) to programatically be able to validate messages of xml that flow in and out of the different systems. Teh validators I used were XSV, oNVDL and lxml, can we implement a pure python module for validating strings of xml using XML Schema (not DTD). lxml is good but not written in python and difficult to install and didn't work on MacOS X. XSV very poor documentation and only validates xml files not strings. oNVDL not writtem in python and only validates xml files not strings.

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Proxy form not getting through
by Greg Ewing March 12, 2008

March 12, 2008

I'm trying to send a proxy form, but all my mail to psf(a)python.org or goodger(a)python.org is getting bounced. Is there another address I can send it to that goes through a different mail server? -- Greg

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Compiler used to build Python for Windows
by Bob Kline March 12, 2008

March 12, 2008

I know this is a topic which has been discussed before (more than once). I'm just adding one more data point. Python.org currently uses VS2003's compiler for building the distributed Windows binaries for Python. Unfortunately, there's a nasty bug in the runtime libraries that support this compiler which causes Python to give the wrong answer when you ask what time it is in most US time zones for four weeks of the year (daylight saving time is observed in that country for four more weeks than those Microsoft's libraries think it is). Even more unfortunate, the patch Microsoft offers is not for the redistributable libraries directly, but for Visual Studio. Worse, Microsoft advises against applying the patch at all, implying that insufficient testing has taken place, urging instead that customers wait for a service pack for Visual Studio which corrects the bug. We've been waiting more than a year, without any indication from MS that this service pack will ever materialize, and it doesn't apply to non-development machines anyway. Every indication seems to point to effective abandonment by Microsoft of those who still use this version of the compiler. http://support.microsoft.com/kb/932299 We don't have conclusive evidence that later versions of Visual Studio are not affected by this bug, but the only KB article we have found for the bug is specific to C runtime library for the 2003 compiler. Any possibility of revisiting this question (upgrading to a more recent compiler for Windows builds of Python)? -- Bob Kline http://www.rksystems.com mailto:bkline@rksystems.com

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[OT] Python mentioned on OOPSLA 2008 postcard
by Brett Cannon March 11, 2008

March 11, 2008

I just got my postcard announcing OOPSLA 2008. Interesting thing is that the postcard, which lists various things that will be at OOPSLA, includes Python. It's actually listed in the first line and the thing is not alphabetized. And even cooler, it is the first language listed (ruby, Objective-C, C#, and Java are also listed). Anyway, thought other might get a kick out of this like I did. -Brett

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[ANN] Python 2.3.7 and 2.4.5 (final)
by "Martin v. Löwis" March 11, 2008

March 11, 2008

On behalf of the Python development team and the Python community, I'm happy to announce the release of Python 2.4.5 and 2.3.7 (final). Both releases include only security fixes. Python 2.5 is the latest version of Python, we're making this release for people who are still running Python 2.3 or 2.4. See the release notes at the website (also available as Misc/NEWS in the source distribution) for details of bugs fixed; most of them prevent interpreter crashes (and now cause proper Python exceptions in cases where the interpreter may have crashed before). Since the release candidate, we received various reports that the this release may fail to build on current operating systems, in particular on OS X. We have made no attempt to fix these problems, as the release is targeted for systems that were current at the time Python 2.4 was originally released. For more recent systems, you might have to come up with work-arounds. For OS X in particular, try invoking:: ./configure MACOSX_DEPLOYMENT_TARGET=10.5 We have made no changes since the release candidate (except for the version numbers). For more information on Python 2.3.7 and 2.4.5, including download links for various platforms, release notes, and known issues, please see: http://www.python.org/2.3.7 http://www.python.org/2.4.5 Highlights of the previous major Python releases are available from the Python 2.4 page, at http://www.python.org/2.3/highlights.html http://www.python.org/2.4/highlights.html Enjoy this release, Martin Martin v. Loewis martin(a)v.loewis.de Python Release Manager (on behalf of the entire python-dev team)

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Re: [Python-Dev] PEP Proposal: Revised slice objects & lists use slice objects as indexes
by Forrest Voight March 10, 2008

March 10, 2008

> I am not sure what you are trying to propose here. The slice object > isn't special, it's just a regular built-in type. The idea is to have slice objects be generators. You could make a slice like 1:10:2 , and that would make a slice object which could be used as a list index. The list would return a list with the corresponding item for every index in the generator. Then, lists could transparently be used as list indexes, or you could supply your own generator instead of a slice object. > I don't see how introducing new syntax would simplify indexing. It would move the slice logic from the list to the slice object. Now the slice object is just a container, but with this it would be useful. > Why should lists accept a list or a generator as an index? What is the > use case you have in mind? For example, a multiple selection box's selection would be changed into its values by supplying the chosen indexes into a list of values. > > Optionally, the 1:2 syntax would create a slice object outside of list > > index areas. > > Again, I don't see how this could be useful... > > > > >>> list(1:5) > > [1, 2, 3, 4] > > > > >>> list(1:5:2) > > [1, 3] > > > > list(range(1,5,2))? It would only be useful as shorthand for xrange, but its addition capabilities would be useful. > > >>> range(30)[1:5 + 15:17] > > [1, 2, 3, 4, 15, 16] > > > > This is confusing, IMHO, and doesn't provide any advantage over: > > >>> s = list(range(30)) > >>> s[1:5] + s[15:17] > I don't think it's confusing. Also, an advantage would be if the slice object were being automatically generated, this would simplify the code. > If you really needed it, you could define a custom class with a fancy > __getitem__ > > class A: > def __getitem__(self, x): > return x > > >>> A()[1:3,2:5] > (slice(1, 3, None), slice(2, 5, None)) > > P.S. You should consider using the python-ideas > (http://mail.python.org/mailman/listinfo/python-ideas) mailing list, > instead of python-dev for posting suggestions. > > Cheers, > -- Alexandre >

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PEP Proposal: Revised slice objects & lists use slice objects as indexes
by Forrest Voight March 10, 2008

March 10, 2008

This would simplify the handling of list slices. Slice objects that are produced in a list index area would be different, and optionally the syntax for slices in list indexes would be expanded to work everywhere. Instead of being containers for the start, end, and step numbers, they would be generators, similar to xranges. Lists would accept these slice objects as indexes, and would also accept any other list or generator. Last, slice objects would be able to be added for multiple index ranges of a list. The new slice object would keep a list of ranges. Optionally, the 1:2 syntax would create a slice object outside of list index areas. It would be shorthand for slice, as [] is for list. This would create some confusion in loops and conditionals due to the colon being used for the end of the structure. (see last example) This would be incompatible with classes that define __setitem__ and __getitem__, and would need changes in how slices are handled in CPython. Therefore, this is probably a proposal for Python 3000. Examples: >>> 1:5 1:5 >>> list(1:5) [1, 2, 3, 4] >>> list(1:5:2) [1, 3] >>> s = 1:3 >>> range(5)[s] [1, 2] >>> 1:5 + 15:17 1:5 + 15:17 >>> range(30)[1:5 + 15:17] [1, 2, 3, 4, 15, 16] >>> range(100)[[1,2,3]] [1, 2, 3] >>> range(100)[1,2,5] # maybe [1, 2, 5] >>> for x in :15:3: print x # maybe 0 3 6 9 12 --- Forrest Voight

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