Mailman 3 December 2008 - Python-Dev

Problem with svn on community buildbot
by skip＠pobox.com 14 Dec '08

14 Dec '08

I have a community buildbot: http://www.python.org/dev/buildbot/community/all/g5%20OSX%202.5/builds/14/s… which is failing the svn checkout of the 2.5 branch: svn: PROPFIND request failed on '/projects/python/branches/release25-maint' svn: PROPFIND of '/projects/python/branches/release25-maint': Could not resolve hostname `svn.python.org': Temporary failure in name resolution (http://svn.python.org) The svn command is: /opt/local/bin/svn checkout --revision 67742 --non-interactive http://svn.python.org/projects/python/branches/release25-maint build Any idea what the problem might be? Thanks, Skip

3 10

How to force export of a particular symbol from python.exe?
by Mark Dickinson 14 Dec '08

14 Dec '08

Hi all, I'm having some trouble making some bits of the Python core code available to extension modules. Specifically, I'm trying to add a function 'Py_force_to_memory' to Python/pymath.c and then use it (via a macro) from Modules/cmathmodule.c. But importing of the cmath module fails with a 'Symbol not found' error. The function is declared with a 'PyAPI_FUNC' in Python/pymath.h. Here's the relevant portion of the make output: *** WARNING: renaming "cmath" since importing it failed: dlopen(build/lib.macosx-10.3-i386-2.7/cmath.so, 2): Symbol not found: _Py_force_to_memory Referenced from: /Users/dickinsm/python_source/branches/trunk/build/lib.macosx-10.3-i386-2.7/cmath.so Expected in: dynamic lookup This is a non-debug trunk build, on OS X (10.5.5), with all the defaults. I'm using Apple's standard toolchain (gcc 4.0.1, Darwin linker). The patch I'm building with can be seen at: http://bugs.python.org/issue4575 (It's the first of the two patches there, called 'force_to_memory.patch'.) I think I understand the cause of this problem; I just don't know how to fix it. The cause seems to be that none of the symbols in pymath.o is used in the Python executable; they're used only in the extension modules. So while the '_Py_force_to_memory' symbol appears in libpython2.7.a, it doesn't appear in the python.exe executable; hence the above error. If I move the definition of Py_force_to_memory from Python/pymath.c to Objects/floatobject.c then everything works as expected. Questions: (1) Is this an OS X only problem? (2) Is there an easy way to force a particular symbol (or all the symbols from a particular object file) to be exported in the Python executable, so that it's available to a dynamically loaded extension module? I've found the -u option to gcc, but this doesn't seem like a particularly portable solution. Of course, if this problem exists only on OS X, then the solution doesn't need to be portable. Thanks, Mark

2 3

2to3 question about fix_imports.
by Lennart Regebro 14 Dec '08

14 Dec '08

The fix_imports fix seems to fix only the first import per line that you have. So if you do for example import urllib2, cStringIO it will not fix cStringIO. Is this a bug or a feature? :-) If it's a feature it should warn at least, right? -- Lennart Regebro: Zope and Plone consulting. http://www.colliberty.com/ +33 661 58 14 64

3 6

beginning developer: fastest way to learn how Python 3.0 works
by Roy Lowrance 13 Dec '08

13 Dec '08

I'd like to learn how Python 3.0 works. I've downloaded the svn. I am wondering what the best way to learn is: - Just jump in? - Or perhaps learn A before B? - Or maybe there is a tutorial for those new to the internals? What's the best way to learn how Python 3.0 works? Roy

4 4

Summary of Python tracker Issues
by Python tracker 12 Dec '08

12 Dec '08

ACTIVITY SUMMARY (12/05/08 - 12/12/08) Python tracker at http://bugs.python.org/ To view or respond to any of the issues listed below, click on the issue number. Do NOT respond to this message. 2261 open (+58) / 14206 closed (+37) / 16467 total (+95) Open issues with patches: 763 Average duration of open issues: 699 days. Median duration of open issues: 2499 days. Open Issues Breakdown open 2242 (+57) pending 19 ( +1) Issues Created Or Reopened (97) _______________________________ Remove mimetools usage from the stdlib 12/06/08 http://bugs.python.org/issue2848 reopened brett.cannon patch improve linecache: reuse tokenize.detect_encoding() and io.open( 12/12/08 http://bugs.python.org/issue4016 reopened benjamin.peterson patch Deprecated python 2.x syntax in "HOWTO Use Python in the web" 12/05/08 CLOSED http://bugs.python.org/issue4550 created jcsalterego patch The python 2.6.1 source distribution is missing Doc/tools/sphinx 12/05/08 CLOSED http://bugs.python.org/issue4551 created andreask Doc/tools/sphinxext not included in the 2.6.1 tarball 12/05/08 CLOSED http://bugs.python.org/issue4552 created doko Results from os.path.islink and os.stat S_ISLNK do not match 12/05/08 CLOSED http://bugs.python.org/issue4553 created npatters Missing make altframeworkinstall for Mac OS X 12/06/08 http://bugs.python.org/issue4554 created christian.heimes Smelly exports 12/06/08 http://bugs.python.org/issue4555 created christian.heimes cmp() function erroneously noted as gone in "What's New" 12/06/08 CLOSED http://bugs.python.org/issue4556 created mwatkins array('c') in python 3.0 produces error, doc says it is ok 12/06/08 CLOSED http://bugs.python.org/issue4557 created lopgok with_stdc89 12/06/08 http://bugs.python.org/issue4558 created christian.heimes patch, patch Whats new recommendation error 12/06/08 CLOSED http://bugs.python.org/issue4559 created lregebro "Flouted", not "flaunted" 12/06/08 CLOSED http://bugs.python.org/issue4560 created jdf Optimize new io library 12/06/08 http://bugs.python.org/issue4561 created christian.heimes patch zip() documentation was not updated 12/06/08 CLOSED http://bugs.python.org/issue4562 created mchouza Wrong formatting of contributor list in About page 12/06/08 http://bugs.python.org/issue4563 created salty-horse bytearray.fromhex doesn't respect bytearray subclass 12/06/08 CLOSED http://bugs.python.org/issue4564 created pitrou io write() performance very slow 12/06/08 http://bugs.python.org/issue4565 created ialbert 2.6.1 breaks many applications that embed Python on Windows 12/06/08 http://bugs.python.org/issue4566 created craigh Registry key not set if unattended installation used 12/06/08 http://bugs.python.org/issue4567 created stuaxo Improved optparse "varargs" callback example 12/06/08 http://bugs.python.org/issue4568 created gregg.lind patch Segfault when mutating a memoryview to an array.array 12/07/08 CLOSED http://bugs.python.org/issue4569 created pitrou Bad example in set tutorial 12/07/08 CLOSED http://bugs.python.org/issue4570 created jmarter write to stdout in binary mode - is it possible? 12/07/08 CLOSED http://bugs.python.org/issue4571 created lopgok add SEEK_* values to io and/or io.IOBase 12/07/08 http://bugs.python.org/issue4572 created gumpy zsh-style subpattern matching for fnmatch/glob 12/07/08 http://bugs.python.org/issue4573 created erickt patch reading UTF16-encoded text file crashes if \r on 64-char boundar 12/07/08 http://bugs.python.org/issue4574 created sjmachin patch Py_IS_INFINITY defect causes test_cmath failure on x86 12/07/08 http://bugs.python.org/issue4575 created marketdickinson patch "Defining new types" little outdated 12/07/08 CLOSED http://bugs.python.org/issue4576 created exe distutils: -3 warnings (apply) 12/07/08 http://bugs.python.org/issue4577 created srittau patch compiler: -3 warnings 12/07/08 http://bugs.python.org/issue4578 created srittau patch .read() and .readline() differ in failing 12/07/08 http://bugs.python.org/issue4579 created eggy patch, needs review slicing of memoryviews when itemsize != 1 is wrong 12/07/08 http://bugs.python.org/issue4580 created pitrou patch, needs review failed to import module from lib-dynload 12/07/08 CLOSED http://bugs.python.org/issue4581 created legerf type of __builtins__ changes if in main module or not 12/07/08 CLOSED http://bugs.python.org/issue4582 created nnorwitz segfault when mutating memoryview to array.array when array is r 12/07/08 http://bugs.python.org/issue4583 created gumpy doctest fails to display bytes type 12/07/08 CLOSED http://bugs.python.org/issue4584 created msyang Build failure on OS X 10.5.5: make: *** [sharedmods] Error 1 12/07/08 CLOSED http://bugs.python.org/issue4585 created marketdickinson "Extending Embedded Python" documention uses removed Py_InitModu 12/07/08 CLOSED http://bugs.python.org/issue4586 created blakemadden Need to rework the dbm lib/include selection process 12/08/08 http://bugs.python.org/issue4587 created skip.montanaro patch, needs review Need a way to make my own bytes 12/08/08 CLOSED http://bugs.python.org/issue4588 created lopgok 'with' loses ->bool exceptions 12/08/08 CLOSED http://bugs.python.org/issue4589 created jyasskin patch 2to3 strips trailing L for long iterals in two fixers 12/08/08 CLOSED http://bugs.python.org/issue4590 created aronacher patch, needs review 32-bits unsigned user/group identifier 12/08/08 http://bugs.python.org/issue4591 created sjoerd patch, needs review Embedding example does not add created module 12/08/08 CLOSED http://bugs.python.org/issue4592 created blakemadden patch, needs review Documentation for multiprocessing - Pool.apply() 12/08/08 http://bugs.python.org/issue4593 created beazley easy Can't compile with -O3, on ARM, with gcc 3.4.4 12/08/08 http://bugs.python.org/issue4594 created metageek new types example is out of date 12/08/08 http://bugs.python.org/issue4595 created blakemadden 2to3 does not fail as early as possible. 12/08/08 http://bugs.python.org/issue4596 created LambertDW EvalFrameEx fails to set 'why' for some exceptions 12/10/08 CLOSED http://bugs.python.org/issue4597 reopened amaury.forgeotdarc patch IDLE not opening 12/08/08 CLOSED http://bugs.python.org/issue4598 created ec2929 Strings undisplayable with repr 12/08/08 CLOSED http://bugs.python.org/issue4599 created mfoord __class__ assignment: new-style? heap? == confusing 12/08/08 http://bugs.python.org/issue4600 created tjreedy directory permission error with make install in 3.0 12/08/08 http://bugs.python.org/issue4601 created legerf patch 2to3 drops executable bit with --write 12/08/08 CLOSED http://bugs.python.org/issue4602 created dato patch 3.0 document tab interpretation change 12/08/08 http://bugs.python.org/issue4603 created tjreedy close() seems to have limited effect 12/09/08 http://bugs.python.org/issue4604 created skip.montanaro patch 3.0 documentation mentions using maketrans from within the strin 12/09/08 http://bugs.python.org/issue4605 created suicideducky Passing 'None' if argtype is set to POINTER(...) doesn't always 12/09/08 http://bugs.python.org/issue4606 created robertluce patch uuid behavior with multiple threads 12/09/08 http://bugs.python.org/issue4607 created mortenab urllib.request.urlopen does not return an iterable object 12/09/08 http://bugs.python.org/issue4608 created jwilk Allow use of > 256 FD's on solaris in 32 bit mode 12/09/08 http://bugs.python.org/issue4609 created pajs(a)fodder.org.uk Unicode case mappings are incorrect 12/09/08 http://bugs.python.org/issue4610 created alexs Small error in "Extending Python with C or C++" 12/09/08 http://bugs.python.org/issue4611 created jakamkon PyModule_Create() doesn't add/import module 12/09/08 CLOSED http://bugs.python.org/issue4612 created blakemadden Can't figure out where SyntaxError: can not delete variable 'x' 12/09/08 http://bugs.python.org/issue4613 created marduk patch Document PyModule_Create() 12/09/08 http://bugs.python.org/issue4614 created brett.cannon needs review de-duping function in itertools 12/10/08 http://bugs.python.org/issue4615 created thomaspinckney3 tarfile does not set the creation date and time of the extracted 12/10/08 CLOSED http://bugs.python.org/issue4616 created throbi SyntaxError when free variable name is also an exception target 12/10/08 http://bugs.python.org/issue4617 created amaury.forgeotdarc patch, needs review print_function and unicode_literals don't work together 12/10/08 http://bugs.python.org/issue4618 created exarkun Invalid Behaviour When a Default Argument is a Mutable Object 12/10/08 CLOSED http://bugs.python.org/issue4619 created rhr Memory leak with datetime used with time.strptime 12/10/08 CLOSED http://bugs.python.org/issue4620 created sebegue zipfile returns string but expects binary 12/10/08 http://bugs.python.org/issue4621 created francescor SequenceMatcher bug with long sequences 12/10/08 http://bugs.python.org/issue4622 created eliben IDLE shutdown if I run an edited file contains chinese 12/11/08 http://bugs.python.org/issue4623 created bianpeng Can not import readline on python3.0 (ubuntu 8.04) 12/11/08 CLOSED http://bugs.python.org/issue4624 created xxiao IDLE won't open anymore, .idlerc unaccessible 12/11/08 http://bugs.python.org/issue4625 created skcheng compile() doesn't ignore the source encoding when a string is pa 12/11/08 http://bugs.python.org/issue4626 created brett.cannon Add Mac OS X Disk Images to Python.org homepage 12/11/08 http://bugs.python.org/issue4627 created carlj No universal newline support for compile() when using bytes 12/11/08 http://bugs.python.org/issue4628 created brett.cannon getopt should not accept no_argument that ends with '=' 12/11/08 http://bugs.python.org/issue4629 created wangchun patch IDLE no longer respects .Xdefaults insertOffTime 12/11/08 http://bugs.python.org/issue4630 created mark urlopen returns extra, spurious bytes 12/11/08 http://bugs.python.org/issue4631 created dato Wrong fix for range(42)[::-1] 12/11/08 CLOSED http://bugs.python.org/issue4632 created theller file.tell() gives wrong result 12/11/08 CLOSED http://bugs.python.org/issue4633 created yavuz164 2to3 should fix "import HTMLParser" 12/11/08 CLOSED http://bugs.python.org/issue4634 created mastrodomenico no reference for optparse methods 12/11/08 http://bugs.python.org/issue4635 created techtonik bdist_wininst installer with install script raises exception 12/11/08 http://bugs.python.org/issue4636 created theller Binary floating point and decimal floating point arithmetic 12/11/08 CLOSED http://bugs.python.org/issue4637 created Retro 1 is 1 is allways true while 1.0 is 1.0 may sometimes be true 12/12/08 CLOSED http://bugs.python.org/issue4638 created nassrat Build failure on OpenBSD 4.4-current regarding lstat() 12/12/08 http://bugs.python.org/issue4639 created vext01 optparse - dosn't distinguish between '--option' and '-option' 12/12/08 http://bugs.python.org/issue4640 created kszawala optparse - dosn't distinguish between '--option' and '-option' 12/12/08 http://bugs.python.org/issue4641 created kszawala optparse - dosn't distinguish between '--option' and '-option' 12/12/08 http://bugs.python.org/issue4642 created kszawala cgitb.html fails if getattr call raises exception 12/12/08 http://bugs.python.org/issue4643 created amc1 Minor documentation fault in 2to3 script 12/12/08 http://bugs.python.org/issue4644 created amc1 Issues Now Closed (74) ______________________ gdbm/ndbm 1.8.1+ needs libgdbm_compat.so 449 days http://bugs.python.org/issue1167 ocean-city patch Victor Stinner's GMP patch for longs 328 days http://bugs.python.org/issue1814 marketdickinson patch Python fails silently on bad locale 291 days http://bugs.python.org/issue2173 marketdickinson patch Full precision summation 214 days http://bugs.python.org/issue2819 marketdickinson patch Incorrect rounding in floating-point operations with gcc/x87 198 days http://bugs.python.org/issue2937 marketdickinson math test fails on Solaris 10 173 days http://bugs.python.org/issue3167 marketdickinson patch Multiprocessing Array and sharedctypes.Array error in docs/imple 165 days http://bugs.python.org/issue3206 amaury.forgeotdarc patch BufferedWriter not thread-safe 129 days http://bugs.python.org/issue3476 wplappert patch expm1 missing 123 days http://bugs.python.org/issue3501 marketdickinson test_math: math.log(-ninf) fails to raise exception on OpenBSD 108 days http://bugs.python.org/issue3682 marketdickinson math.log(x, 10) gives different result than math.log10(x) 98 days http://bugs.python.org/issue3724 marketdickinson patch _lsprof: clear() should call flush_unmatched() 79 days http://bugs.python.org/issue3952 haypo patch tokenize.detect_encoding(): raise SyntaxError on codecs.lookup() 70 days http://bugs.python.org/issue4021 benjamin.peterson patch, patch, needs review Decimal.max(NaN, x) gives incorrect results when x is finite and 63 days http://bugs.python.org/issue4084 marketdickinson patch ihooks incompatible with absolute_import feature 35 days http://bugs.python.org/issue4244 georg.brandl Update pydoc URLs 36 days http://bugs.python.org/issue4259 loewis smtplib.py initialisation defect 28 days http://bugs.python.org/issue4302 ocean-city patch state_reset not called on 'state' before sre_search invoked 16 days http://bugs.python.org/issue4416 amaury.forgeotdarc String allocations waste 3 bytes of memory on average. 9 days http://bugs.python.org/issue4445 marketdickinson patch __import__ documentation obsolete 9 days http://bugs.python.org/issue4457 georg.brandl patch parameters of PyLong_FromString() are not checked for NULL 6 days http://bugs.python.org/issue4461 marketdickinson patch Windows installer crash 4 days http://bugs.python.org/issue4481 tjreedy Error to build _dbm module during make 6 days http://bugs.python.org/issue4483 skip.montanaro patch, easy Python Documentation not Newb Friendly 4 days http://bugs.python.org/issue4488 georg.brandl Compiler warnings in longobject.c 3 days http://bugs.python.org/issue4497 marketdickinson patch 3.0 test failure on Mac OS X 10.5.5 2 days http://bugs.python.org/issue4507 marketdickinson Decorators should have an index entry 2 days http://bugs.python.org/issue4511 georg.brandl problem with str.join - should work with list input, error says 1 days http://bugs.python.org/issue4534 lopgok webbrowser.UnixBrowser should use builtins.open 1 days http://bugs.python.org/issue4537 amaury.forgeotdarc A defect in <The Python Tutorial>-<Python Scopes and Name Spaces 0 days http://bugs.python.org/issue4549 georg.brandl Deprecated python 2.x syntax in "HOWTO Use Python in the web" 0 days http://bugs.python.org/issue4550 georg.brandl patch The python 2.6.1 source distribution is missing Doc/tools/sphinx 0 days http://bugs.python.org/issue4551 georg.brandl Doc/tools/sphinxext not included in the 2.6.1 tarball 3 days http://bugs.python.org/issue4552 georg.brandl Results from os.path.islink and os.stat S_ISLNK do not match 0 days http://bugs.python.org/issue4553 christian.heimes cmp() function erroneously noted as gone in "What's New" 0 days http://bugs.python.org/issue4556 georg.brandl array('c') in python 3.0 produces error, doc says it is ok 0 days http://bugs.python.org/issue4557 georg.brandl Whats new recommendation error 1 days http://bugs.python.org/issue4559 lregebro "Flouted", not "flaunted" 0 days http://bugs.python.org/issue4560 georg.brandl zip() documentation was not updated 0 days http://bugs.python.org/issue4562 georg.brandl bytearray.fromhex doesn't respect bytearray subclass 0 days http://bugs.python.org/issue4564 amaury.forgeotdarc Segfault when mutating a memoryview to an array.array 1 days http://bugs.python.org/issue4569 pitrou Bad example in set tutorial 0 days http://bugs.python.org/issue4570 rhettinger write to stdout in binary mode - is it possible? 1 days http://bugs.python.org/issue4571 christian.heimes "Defining new types" little outdated 0 days http://bugs.python.org/issue4576 georg.brandl failed to import module from lib-dynload 0 days http://bugs.python.org/issue4581 loewis type of __builtins__ changes if in main module or not 0 days http://bugs.python.org/issue4582 loewis doctest fails to display bytes type 0 days http://bugs.python.org/issue4584 georg.brandl Build failure on OS X 10.5.5: make: *** [sharedmods] Error 1 1 days http://bugs.python.org/issue4585 marketdickinson "Extending Embedded Python" documention uses removed Py_InitModu 2 days http://bugs.python.org/issue4586 georg.brandl Need a way to make my own bytes 0 days http://bugs.python.org/issue4588 loewis 'with' loses ->bool exceptions 3 days http://bugs.python.org/issue4589 amaury.forgeotdarc patch 2to3 strips trailing L for long iterals in two fixers 1 days http://bugs.python.org/issue4590 aronacher patch, needs review Embedding example does not add created module 1 days http://bugs.python.org/issue4592 georg.brandl patch, needs review EvalFrameEx fails to set 'why' for some exceptions 0 days http://bugs.python.org/issue4597 jyasskin patch IDLE not opening 2 days http://bugs.python.org/issue4598 loewis Strings undisplayable with repr 0 days http://bugs.python.org/issue4599 loewis 2to3 drops executable bit with --write 3 days http://bugs.python.org/issue4602 benjamin.peterson patch PyModule_Create() doesn't add/import module 0 days http://bugs.python.org/issue4612 amaury.forgeotdarc tarfile does not set the creation date and time of the extracted 2 days http://bugs.python.org/issue4616 lars.gustaebel Invalid Behaviour When a Default Argument is a Mutable Object 0 days http://bugs.python.org/issue4619 loewis Memory leak with datetime used with time.strptime 1 days http://bugs.python.org/issue4620 skip.montanaro Can not import readline on python3.0 (ubuntu 8.04) 0 days http://bugs.python.org/issue4624 benjamin.peterson Wrong fix for range(42)[::-1] 0 days http://bugs.python.org/issue4632 benjamin.peterson file.tell() gives wrong result 0 days http://bugs.python.org/issue4633 QuantumTim 2to3 should fix "import HTMLParser" 0 days http://bugs.python.org/issue4634 benjamin.peterson Binary floating point and decimal floating point arithmetic 0 days http://bugs.python.org/issue4637 gvanrossum 1 is 1 is allways true while 1.0 is 1.0 may sometimes be true 0 days http://bugs.python.org/issue4638 tim_one Proto 2 pickle vs dict subclass 1873 days http://bugs.python.org/issue826897 benjamin.peterson Python interpreter stalled on _PyPclose.WaitForSingleObject 1708 days http://bugs.python.org/issue928332 amaury.forgeotdarc Fix for #777597 - socketmodule.c connection handling incorec 1647 days http://bugs.python.org/issue965036 amaury.forgeotdarc patch distutils' dry-run wants to create some real build dirs 1545 days http://bugs.python.org/issue1030250 amaury.forgeotdarc patch correct/clarify documentation for super 1363 days http://bugs.python.org/issue1163367 rhettinger sys.settrace cause curried parms to show up as attributes 796 days http://bugs.python.org/issue1569356 loewis thread + import => crashes? 292 days http://bugs.python.org/issue1720705 forest Top Issues Most Discussed (10) ______________________________ 42 Get rid of more refercenes to __cmp__ 57 days open http://bugs.python.org/issue1717 23 slicing of memoryviews when itemsize != 1 is wrong 5 days open http://bugs.python.org/issue4580 17 Make conversions from long to float correctly rounded. 174 days open http://bugs.python.org/issue3166 13 Optimize new io library 6 days open http://bugs.python.org/issue4561 12 bugs in array.array with exports (buffer protocol) 9 days open http://bugs.python.org/issue4509 11 Whats new recommendation error 1 days closed http://bugs.python.org/issue4559 11 Error to build _dbm module during make 6 days closed http://bugs.python.org/issue4483 10 with_stdc89 7 days open http://bugs.python.org/issue4558 9 tarfile does not set the creation date and time of the extracte 2 days closed http://bugs.python.org/issue4616 9 'with' loses ->bool exceptions 3 days closed http://bugs.python.org/issue4589

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Build failure on OpenBSD 4.4-current
by Edd Barrett 12 Dec '08

12 Dec '08

Hi, I just had to move the "extern lstat..." outside the "ifndef HAVE_LSTAT" to get python 2.6.1 to build on OpenBSD 4.4-current/i386. I'm not suggesting this is correct, but it fixes the build for my platform at least. --- Modules/posixmodule.c.orig Fri Dec 12 11:08:54 2008 +++ Modules/posixmodule.c Fri Dec 12 11:54:16 2008 @@ -208,10 +208,11 @@ #ifdef HAVE_SYMLINK extern int symlink(const char *, const char *); #endif /* HAVE_SYMLINK */ +#endif /* !HAVE_UNISTD_H */ + #ifdef HAVE_LSTAT extern int lstat(const char *, struct stat *); #endif /* HAVE_LSTAT */ -#endif /* !HAVE_UNISTD_H */ #endif /* !_MSC_VER */ Im using gcc-4.2 Thanks -- Best Regards Edd http://students.dec.bournemouth.ac.uk/ebarrett

2 2

Merging flow
by Christian Heimes 11 Dec '08

11 Dec '08

Several people have asked about the patch and merge flow. Now that Python 3.0 is out it's a bit more complicated. Flow diagram ------------ trunk ---> release26-maint \-> py3k ---> release30-maint Patches for all versions of Python should land in the trunk. They are then merged into release26-maint and py3k branches. Changes for Python 3.0 are merged via the py3k branch. Christian

11 26

Allocation of shape and strides fields in Py_buffer
by Antoine Pitrou 10 Dec '08

10 Dec '08

Hello, The Py_buffer struct has two pointers named `shape` and `strides`. Each points to an array of Py_ssize_t values whose length is equal to the number of dimensions of the buffer object. Unfortunately, the buffer protocol spec doesn't explain how allocation of these arrays should be handled. Right now this is circumvented by either pointing them to an externally-managed piece of memory (e.g. a Py_ssize_t field in the original PyObject), or by pointing them to another field in the Py_buffer (because in the case of a one-dimensional buffer with itemsize == 1, shape[0] is simply equal to the length of the buffer in bytes). Of course this is not flexible, and it makes fixing the situation with buffers of itemsize larger than 1 difficult (indeed, for those buffers, we can't simply point the shape array to the byte length, and if we are taking a slice of the memoryview, we can't either point it to the size of the original object (for example an array.array)). Therefore, arises the problem of allocation of the shape array. For the one-dimensional case, I had in mind a simple scheme where the Py_buffer struct has an additional two-member Py_ssize_t array. Then `shape` and `strides` can point to the first and second member of this array, respectively. This wouldn't solve the multi-dimensional case, however. Thanks for any ideas on how to solve this. Regards Antoine.

5 36

datetime.date.today() raises "AttributeError: time"
by Tal Einat 10 Dec '08

10 Dec '08

For an unknown reason, datetime.date.today() began throwing a cryptic "AttributeError: time" exception. It took me a while to figure out that this was caused by an accidental overriding of the built-in 'time' module. Here's an example interactive session which shows the problem: [tal ~]$ touch time.py [tal ~]$ python Python 2.5.2 (r252:60911, Jul 17 2008, 10:47:50) [GCC 4.0.1 (Apple Inc. build 5484)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import time >>> time.__file__ 'time.py' >>> import datetime >>> datetime.date.today() Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: time >>> Here I used version 2.5.2, but I checked and this also happens on 2.6. It this desired behavior? At the very least the exception should be more detailed, perhaps to the point of suggesting the probable cause of the error (i.e. overriding the time module). - Tal

6 7

Floating-point implementations
by Steve Holden 10 Dec '08

10 Dec '08

Is anyone aware of any implementations that use other than 64-bit floating-point? I'd be particularly interested in any that use greater precision than the usual 56-bit mantissa. Do modern 64-bit systems implement anything wider than the normal double? regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/

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Python-Dev December 2008