Mailman 3 August 2012 - Python-Dev

Python 2.7: only Visual Studio 2008?
by Luc Bourhis 07 Sep '12

07 Sep '12

Greetings, it is my understanding that the patches floating around the net to support Visual Studio 2010 to compile the Python core and for distutils will never be accepted and therefore that the 2.7 line is stuck to VS 2008 for the remaining of its life. Could you please confirm that? Best wishes, Luc

7 11

Re: [Python-Dev] benchmarks: Pathlib works under Python 3.
by Antoine Pitrou 31 Aug '12

31 Aug '12

On Fri, 31 Aug 2012 17:52:38 +0200 (CEST) brett.cannon <python-checkins(a)python.org> wrote: > http://hg.python.org/benchmarks/rev/873baf08045e > changeset: 162:873baf08045e > user: Brett Cannon <brett(a)python.org> > date: Fri Aug 31 11:52:30 2012 -0400 > summary: > Pathlib works under Python 3. ... but therefore you shouldn't run it under 2to3 (which may pessimize the code). Benchmarks with a 3.x-compatible code base are listed under the "2n3" meta-benchmark name in perf.py: http://hg.python.org/benchmarks/file/873baf08045e/perf.py#l2000 Regards Antoine. -- Software development and contracting: http://pro.pitrou.net

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Summary of Python tracker Issues
by Python tracker 31 Aug '12

31 Aug '12

ACTIVITY SUMMARY (2012-08-24 - 2012-08-31) Python tracker at http://bugs.python.org/ To view or respond to any of the issues listed below, click on the issue. Do NOT respond to this message. Issues counts and deltas: open 3653 (+13) closed 23955 (+41) total 27608 (+54) Open issues with patches: 1621 Issues opened (37) ================== #15780: IDLE (windows) with PYTHONPATH and multiple python versions http://bugs.python.org/issue15780 opened by Jimbofbx #15782: Compile error for a number of Mac modules with recent Xcode http://bugs.python.org/issue15782 opened by ronaldoussoren #15783: decimal.localcontext(None) fails when using the C accelerator http://bugs.python.org/issue15783 opened by ncoghlan #15784: OSError.__str__() should distinguish between errno and winerro http://bugs.python.org/issue15784 opened by sbt #15785: curses.get_wch() returns keypad codes incorrectly http://bugs.python.org/issue15785 opened by simpkins #15786: IDLE code completion window does not scoll/select with mouse http://bugs.python.org/issue15786 opened by suddha.sourav #15787: PEP 3121 Refactoring http://bugs.python.org/issue15787 opened by belopolsky #15789: mention shell-like parts of the std lib in the subprocess docs http://bugs.python.org/issue15789 opened by cvrebert #15792: Fix compiler options for x64 builds on Windows http://bugs.python.org/issue15792 opened by jkloth #15793: Stack corruption in ssl.RAND_egd() http://bugs.python.org/issue15793 opened by storchaka #15795: Zipfile.extractall does not preserve file permissions http://bugs.python.org/issue15795 opened by uruz #15796: Fix readline() docstrings http://bugs.python.org/issue15796 opened by storchaka #15797: bdist_msi does not pass -install/remove flags to install_scrip http://bugs.python.org/issue15797 opened by braudel #15798: subprocess.Popen() fails if 0, 1 or 2 descriptor is closed http://bugs.python.org/issue15798 opened by sarum9in #15799: httplib client and statusline http://bugs.python.org/issue15799 opened by karlcow #15802: Nonsensical test for mailbox http://bugs.python.org/issue15802 opened by storchaka #15803: Incorrect docstring on ConfigParser.items() http://bugs.python.org/issue15803 opened by nbtrap #15805: Add stdout redirection tool to contextlib http://bugs.python.org/issue15805 opened by rhettinger #15806: Add context manager for the "try: ... except: pass" pattern http://bugs.python.org/issue15806 opened by rhettinger #15808: Possibility of setting custom key bindings for "Additional hel http://bugs.python.org/issue15808 opened by Rostyslav.Dzinko #15809: IDLE console uses incorrect encoding. http://bugs.python.org/issue15809 opened by alex.hartwig #15810: assertSequenceEqual should be fired when comparing sequence su http://bugs.python.org/issue15810 opened by flox #15811: ElementTree.write() raises TypeError when xml_declaration = Tr http://bugs.python.org/issue15811 opened by David.Buxton #15812: inspect.getframeinfo() cannot show first line http://bugs.python.org/issue15812 opened by sbt #15814: memoryview: equality-hash invariant http://bugs.python.org/issue15814 opened by skrah #15815: Add numerator to ZeroDivisionError messages http://bugs.python.org/issue15815 opened by terry.reedy #15817: Misc/gdbinit: Expose command documentation to gdb help http://bugs.python.org/issue15817 opened by belopolsky #15818: multiprocessing documentation of Process.exitcode http://bugs.python.org/issue15818 opened by schmiddy #15819: Unable to build Python out-of-tree when source tree is readonl http://bugs.python.org/issue15819 opened by trent #15820: Add additional info to Resources area on Dev Guide http://bugs.python.org/issue15820 opened by mikehoy #15821: Improve docs for PyMemoryView_FromBuffer() http://bugs.python.org/issue15821 opened by skrah #15822: Python 3.3 creates lib2to3 grammar in wrong order http://bugs.python.org/issue15822 opened by tpievila #15826: Increased test coverage of test_glob.py http://bugs.python.org/issue15826 opened by eng793 #15828: imp.load_module doesn't support C_EXTENSION type http://bugs.python.org/issue15828 opened by metolone #15829: Threading Lock - Wrong Exception Name http://bugs.python.org/issue15829 opened by mikehoy #15830: make -s no longer silences output from setup.py http://bugs.python.org/issue15830 opened by brett.cannon #15831: comma after leading optional argument is after bracket in docs http://bugs.python.org/issue15831 opened by cjerdonek Most recent 15 issues with no replies (15) ========================================== #15831: comma after leading optional argument is after bracket in docs http://bugs.python.org/issue15831 #15830: make -s no longer silences output from setup.py http://bugs.python.org/issue15830 #15826: Increased test coverage of test_glob.py http://bugs.python.org/issue15826 #15818: multiprocessing documentation of Process.exitcode http://bugs.python.org/issue15818 #15817: Misc/gdbinit: Expose command documentation to gdb help http://bugs.python.org/issue15817 #15812: inspect.getframeinfo() cannot show first line http://bugs.python.org/issue15812 #15797: bdist_msi does not pass -install/remove flags to install_scrip http://bugs.python.org/issue15797 #15796: Fix readline() docstrings http://bugs.python.org/issue15796 #15782: Compile error for a number of Mac modules with recent Xcode http://bugs.python.org/issue15782 #15772: Unresolved symbols in Windows 64-bit python http://bugs.python.org/issue15772 #15767: add ModuleNotFoundError http://bugs.python.org/issue15767 #15759: "make suspicious" doesn't display instructions in case of fail http://bugs.python.org/issue15759 #15744: missing tests for {RawIO,BufferedIO,TextIO}.writelines http://bugs.python.org/issue15744 #15735: PEP 3121, 384 Refactoring applied to ossaudio module http://bugs.python.org/issue15735 #15734: PEP 3121, 384 Refactoring applied to spwd module http://bugs.python.org/issue15734 Most recent 15 issues waiting for review (15) ============================================= #15829: Threading Lock - Wrong Exception Name http://bugs.python.org/issue15829 #15828: imp.load_module doesn't support C_EXTENSION type http://bugs.python.org/issue15828 #15826: Increased test coverage of test_glob.py http://bugs.python.org/issue15826 #15821: Improve docs for PyMemoryView_FromBuffer() http://bugs.python.org/issue15821 #15820: Add additional info to Resources area on Dev Guide http://bugs.python.org/issue15820 #15819: Unable to build Python out-of-tree when source tree is readonl http://bugs.python.org/issue15819 #15817: Misc/gdbinit: Expose command documentation to gdb help http://bugs.python.org/issue15817 #15814: memoryview: equality-hash invariant http://bugs.python.org/issue15814 #15811: ElementTree.write() raises TypeError when xml_declaration = Tr http://bugs.python.org/issue15811 #15809: IDLE console uses incorrect encoding. http://bugs.python.org/issue15809 #15808: Possibility of setting custom key bindings for "Additional hel http://bugs.python.org/issue15808 #15803: Incorrect docstring on ConfigParser.items() http://bugs.python.org/issue15803 #15802: Nonsensical test for mailbox http://bugs.python.org/issue15802 #15798: subprocess.Popen() fails if 0, 1 or 2 descriptor is closed http://bugs.python.org/issue15798 #15797: bdist_msi does not pass -install/remove flags to install_scrip http://bugs.python.org/issue15797 Top 10 most discussed issues (10) ================================= #15819: Unable to build Python out-of-tree when source tree is readonl http://bugs.python.org/issue15819 23 msgs #15814: memoryview: equality-hash invariant http://bugs.python.org/issue15814 18 msgs #15783: decimal.localcontext(None) fails when using the C accelerator http://bugs.python.org/issue15783 14 msgs #15785: curses.get_wch() returns keypad codes incorrectly http://bugs.python.org/issue15785 14 msgs #15751: Support subinterpreters in the GIL state API http://bugs.python.org/issue15751 13 msgs #15776: Allow pyvenv to work in existing directory http://bugs.python.org/issue15776 12 msgs #15798: subprocess.Popen() fails if 0, 1 or 2 descriptor is closed http://bugs.python.org/issue15798 11 msgs #15806: Add context manager for the "try: ... except: pass" pattern http://bugs.python.org/issue15806 10 msgs #15828: imp.load_module doesn't support C_EXTENSION type http://bugs.python.org/issue15828 9 msgs #15829: Threading Lock - Wrong Exception Name http://bugs.python.org/issue15829 9 msgs Issues closed (35) ================== #10650: decimal.py: quantize(): excess digits with watchexp=0 http://bugs.python.org/issue10650 closed by python-dev #11225: getcwd fix for NetBSD to handle ERANGE errno http://bugs.python.org/issue11225 closed by neologix #11964: Undocumented change to indent param of json.dump in 3.2 http://bugs.python.org/issue11964 closed by petri.lehtinen #13370: test_ctypes fails when building python with clang http://bugs.python.org/issue13370 closed by ronaldoussoren #13518: configparser can’t read file objects from urlopen http://bugs.python.org/issue13518 closed by pitrou #14042: json.dumps() documentation is slightly incorrect. http://bugs.python.org/issue14042 closed by petri.lehtinen #14674: Link to & explain deviations from RFC 4627 in json module docs http://bugs.python.org/issue14674 closed by pitrou #14880: csv.reader and .writer use wrong kwargs notation in 2.7 docs http://bugs.python.org/issue14880 closed by hynek #15136: Decimal accepting Fraction http://bugs.python.org/issue15136 closed by rhettinger #15544: math.isnan fails with some Decimal NaNs http://bugs.python.org/issue15544 closed by mark.dickinson #15573: Support unknown formats in memoryview comparisons http://bugs.python.org/issue15573 closed by python-dev #15591: when building the extensions, stdout is lost when stdout is re http://bugs.python.org/issue15591 closed by doko #15720: move __import__() out of the default lookup chain http://bugs.python.org/issue15720 closed by benjamin.peterson #15724: Add "versionchanged" to memoryview docs http://bugs.python.org/issue15724 closed by skrah #15761: Setting PYTHONEXECUTABLE can cause segfaults on OS X http://bugs.python.org/issue15761 closed by ronaldoussoren #15765: test_getcwd_long_pathnames (in test_posix) kills NetBSD http://bugs.python.org/issue15765 closed by trent #15777: test_capi refleak http://bugs.python.org/issue15777 closed by rosslagerwall #15778: str(ImportError(b'foo')) fails http://bugs.python.org/issue15778 closed by brett.cannon #15779: socket error [Errno 10013] when creating SMTP object http://bugs.python.org/issue15779 closed by loewis #15781: test_threaded_import fails with -j4 http://bugs.python.org/issue15781 closed by pitrou #15788: cross-refs in the subprocess.Popen.std{in,out,err} warning box http://bugs.python.org/issue15788 closed by ezio.melotti #15790: Python 3.3.0rc1 release notes claims PEP-405 support, yet pyse http://bugs.python.org/issue15790 closed by pas #15791: pydoc does not handle non-ASCII unicode AUTHOR field http://bugs.python.org/issue15791 closed by r.david.murray #15794: test_importlib: test_locks failure http://bugs.python.org/issue15794 closed by pitrou #15800: Closing of sys.std* files in gzip test. http://bugs.python.org/issue15800 closed by pitrou #15801: Weird string interpolation behaviour http://bugs.python.org/issue15801 closed by python-dev #15804: Feature request, implicit "except : pass" http://bugs.python.org/issue15804 closed by benjamin.peterson #15807: Bogus versionchanged note in logging.handlers.MemoryHandler do http://bugs.python.org/issue15807 closed by python-dev #15813: Python function decorator scope losing variable http://bugs.python.org/issue15813 closed by r.david.murray #15816: pydoc.py uses a hack that depends on implementation details an http://bugs.python.org/issue15816 closed by r.david.murray #15823: argparse produces error when multiply help lines http://bugs.python.org/issue15823 closed by r.david.murray #15824: mutable urlparse return type http://bugs.python.org/issue15824 closed by r.david.murray #15825: Typo in OrderedDict docs http://bugs.python.org/issue15825 closed by asvetlov #15827: Use "ll" for PY_FORMAT_SIZE_T on Win64 http://bugs.python.org/issue15827 closed by scoder #1432343: Description of file-object read() method is wrong. http://bugs.python.org/issue1432343 closed by r.david.murray

1 0

why is _PyBytes_Join not public but PyUnicode_Join is?
by Gregory P. Smith 31 Aug '12

31 Aug '12

We have use for _PyBytes_Join in an extension module but technically it isn't a public Python C API... anyone know why? PyUnicode_Join is. Looking up the bytes 'join' method and using the C API to call that method object with proper parameters seems like overkill in the case where we're not dealing with user supplied byte strings at all. -gps

5 4

Problem with _PyTrash_destroy_chain ?
by Manu 30 Aug '12

30 Aug '12

Hi, I am currently hitting http://bugs.python.org/issue13992. I have a scenario that reproduces the bug after 1 to 2 hours (intensive sqlalchemy and threading). I get the same stack trace as described in the bug. After spending quite a bit of time trying to understand what could go wrong in the C extensions I use, and not finding anything interesting, I decided to try to find the problem with gdb. The stacktrace I have seems to mean that we are trying to double free something in the frame_dealloc method. See (gdb) bt #0 0x000000000046479f in _Py_ForgetReference (op=0x4dc7bc0) at Objects/object.c:2222 #1 0x0000000000464810 in _Py_Dealloc (op=0x4dc7bc0) at Objects/object.c:2242 #2 0x0000000000559a68 in frame_dealloc (f=0x4997ab0) at Objects/frameobject.c:458 #3 0x000000000046481d in _Py_Dealloc (op=0x4997ab0) at Objects/object.c:2243 and info in the bug report. Since the frame dealloc method is bracketed with Py_TRASHCAN_SAFE_{BEGIN|END} macros, and they deal with memory management, I had a closer look at those. I compiled cpython without this trashcan management (replaced the macros by two noops) and reran my scenario and it seems it is not segfaulting anymore. I then had a closer look at the PyTrash_destroy_chain method (in object.c). Here is what I think it does : for each PyObject in the _PyTrash_delete_later linked list do : set delete_nesting to 1 (it was 0 when the method was called) so that we don't call destroy_chain again. call deallocator for the object set delete_nesting back to 1. The thing is that this deallocator (from what I understood) is also bracketed with Py_TRASHCAN macros. It could potentially cause a long deallocation chain, that will be added to the _PyTrash_delete_later linked list (if it's bigger than the PyTrash_UNWIND_LEVEL). If that happens, it seems that the _PyTrash_delete_later list is going to contain twice the same object, which could in turn cause the double free ? Note that I am really not sure about this. What I am now almost sure about is that my segfault goes away if I bypass the trashcan mechanism. I am currently trying to set the unwind level to something like 5 and get a quicker way to reproduce the bug, but I didn't manage to yet. I am definitely available for help if needed. Thanks, Manu

3 4

hg.python.org should default to defaut, not 2.7
by Terry Reedy 30 Aug '12

30 Aug '12

If one goes to http://hg.python.org/cpython/ and clicks 'browse', it defaults to 2.7, not to default (now 3.3). Moreover, there is no indication that it is defaulting to an old branch rather than current default, as one might reasonably expect. I found this very confusing when I was trying to get a link for a python-list post and the code did not look right. When one clicks 'branches', default is listed under 2.7, instead of on top, where it should be. I hope someone can fix both these issues. -- Terry Jan Reedy

6 7

Py_buffer.obj documentation
by Alexander Belopolsky 30 Aug '12

30 Aug '12

I am trying to reconcile this section in 3.3 documentation: """ void *obj A new reference to the exporting object. The reference is owned by the consumer and automatically decremented and set to NULL by PyBuffer_Release(). The field is the equivalent of the return value of any standard C-API function. As a special case, for temporary buffers that are wrapped by PyMemoryView_FromBuffer() or PyBuffer_FillInfo() this field is NULL. In general, exporting objects MUST NOT use this scheme. """ -- http://docs.python.org/dev/c-api/buffer.html#Py_buffer.obj with the following comment in the code (Objects/memoryobject.c:762): /* info->obj is either NULL or a borrowed reference. This reference should not be decremented in PyBuffer_Release(). */ I have not studied the code yet, but given the history of bugs in this area the code may not have the most authoritative answer. In any case, either the comment or the ReST section should be corrected.

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Re: [Python-Dev] [Python-checkins] cpython (merge 3.2 -> default): merge 3.2 (#15801)
by Petri Lehtinen 29 Aug '12

29 Aug '12

Hi, benjamin.peterson wrote: > http://hg.python.org/cpython/rev/263d09ce3e9e > changeset: 78794:263d09ce3e9e > parent: 78790:454dceb5fd56 > parent: 78793:4d431e719646 > user: Benjamin Peterson <benjamin(a)python.org> > date: Tue Aug 28 18:01:45 2012 -0400 > summary: > merge 3.2 (#15801) > > files: > Lib/test/string_tests.py | 3 +++ > Misc/NEWS | 3 +++ > Objects/unicodeobject.c | 3 +-- > 3 files changed, 7 insertions(+), 2 deletions(-) > [snip] > diff --git a/Misc/NEWS b/Misc/NEWS > --- a/Misc/NEWS > +++ b/Misc/NEWS > @@ -71,6 +71,9 @@ > > - Issue #15761: Fix crash when PYTHONEXECUTABLE is set on Mac OS X. > > +- Issue #15801: Make sure mappings passed to '%' formatting are actually > + subscriptable. > + > - Issue #15726: Fix incorrect bounds checking in PyState_FindModule. > Patch by Robin Schreiber. The news entry was added in the middle of the news for 3.3.0 RC 1, which has already been released. Petri

1 0

Copyediting PEPs
by Chris Angelico 29 Aug '12

29 Aug '12

What's the procedure for making trivial edits to a PEP? I was (re)reading PEP 393 and found a couple of typos (PyCompactObject s/be PyCompactUnicodeObject and "differs form length" s/be "from"). Can I edit them directly in the web site's SVN repo, or should a patch be submitted? Apologies for the perhaps clueless question! ChrisA

3 5

Re: [Python-Dev] [Python-checkins] cpython: Issue #15794: Relax a test case due to the deadlock detection's
by Brett Cannon 28 Aug '12

28 Aug '12

Should there be a Misc/NEWS entry since we are in rc mode? On Tue, Aug 28, 2012 at 2:13 PM, antoine.pitrou <python-checkins(a)python.org>wrote: > http://hg.python.org/cpython/rev/454dceb5fd56 > changeset: 78790:454dceb5fd56 > parent: 78788:06497bbdf4fe > user: Antoine Pitrou <solipsis(a)pitrou.net> > date: Tue Aug 28 20:10:18 2012 +0200 > summary: > Issue #15794: Relax a test case due to the deadlock detection's > conservativeness. > > files: > Lib/test/test_importlib/test_locks.py | 22 ++++++++++++-- > 1 files changed, 18 insertions(+), 4 deletions(-) > > > diff --git a/Lib/test/test_importlib/test_locks.py > b/Lib/test/test_importlib/test_locks.py > --- a/Lib/test/test_importlib/test_locks.py > +++ b/Lib/test/test_importlib/test_locks.py > @@ -1,4 +1,5 @@ > from importlib import _bootstrap > +import sys > import time > import unittest > import weakref > @@ -41,6 +42,17 @@ > @unittest.skipUnless(threading, "threads needed for this test") > class DeadlockAvoidanceTests(unittest.TestCase): > > + def setUp(self): > + try: > + self.old_switchinterval = sys.getswitchinterval() > + sys.setswitchinterval(0.000001) > + except AttributeError: > + self.old_switchinterval = None > + > + def tearDown(self): > + if self.old_switchinterval is not None: > + sys.setswitchinterval(self.old_switchinterval) > + > def run_deadlock_avoidance_test(self, create_deadlock): > NLOCKS = 10 > locks = [LockType(str(i)) for i in range(NLOCKS)] > @@ -75,10 +87,12 @@ > > def test_deadlock(self): > results = self.run_deadlock_avoidance_test(True) > - # One of the threads detected a potential deadlock on its second > - # acquire() call. > - self.assertEqual(results.count((True, False)), 1) > - self.assertEqual(results.count((True, True)), len(results) - 1) > + # At least one of the threads detected a potential deadlock on its > + # second acquire() call. It may be several of them, because the > + # deadlock avoidance mechanism is conservative. > + nb_deadlocks = results.count((True, False)) > + self.assertGreaterEqual(nb_deadlocks, 1) > + self.assertEqual(results.count((True, True)), len(results) - > nb_deadlocks) > > def test_no_deadlock(self): > results = self.run_deadlock_avoidance_test(False) > > -- > Repository URL: http://hg.python.org/cpython > > _______________________________________________ > Python-checkins mailing list > Python-checkins(a)python.org > http://mail.python.org/mailman/listinfo/python-checkins > >

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Python-Dev August 2012