Mailman 3 October 2010 - Python-Dev

PPC Tiger is back up
by Bill Janssen Oct. 16, 2010

Oct. 16, 2010

I've moved the OS X buildbot parc-tiger-1 (PPC Tiger) to new hardware, a MDD dual-G4 PowerMac with more memory. Should move considerably faster. Enjoy! Bill

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Fwd: [Python-ideas] stats module Was: minmax() function ...
by Raymond Hettinger Oct. 16, 2010

Oct. 16, 2010

Hello guys. If you don't mind, I would like to hijack your thread :-) ISTM, that the minmax() idea is really just an optimization request. A single-pass minmax() is easily coded in simple, pure-python, so really the discussion is about how to remove the loop overhead (there isn't much you can do about the cost of the two compares which is where most of the time would be spent anyway). My suggestion is to aim higher. There is no reason a single pass couldn't also return min/max/len/sum and perhaps even other summary statistics like sum(x**2) so that you can compute standard deviation and variance. A few years ago, Guido and other python devvers supported a proposal I made to create a stats module, but I didn't have time to develop it. The basic idea was that python's batteries should include most of the functionality available on advanced student calculators. Another idea behind it was that we could invisibility do-the-right-thing under the hood to help users avoid numerical problems (i.e. math.fsum(s)/len(s) is a more accurate way to compute an average because it doesn't lose precision when building-up the intermediate sums). I think the creativity and energy of this group is much better directed at building a quality stats module (perhaps with some R-like capabilities). That would likely be a better use of energy than bike-shedding about ways to speed-up a trivial piece of code that is ultimately constrained by the cost of the compares per item. my-two-cents, Raymond

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A new warning category?
by Antoine Pitrou Oct. 15, 2010

Oct. 15, 2010

Hello, In the http://bugs.python.org/issue10093 discussion, I proposed to add a specific warning category for unclosed files. The rationale is that these warnings will happen in destructors and therefore filtering by line number and filename doesn't make sense. So a new category would be useful in order to allow defining specific rules. Do you think it would go against the moratorium? As for the category name, I would suggest ResourceWarning if we use it specifically for resource-consumption warnings. Or perhaps DebugWarning if we want to put all kinds of debugging helpers in it. Regards Antoine.

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Summary of Python tracker Issues
by Python tracker Oct. 15, 2010

Oct. 15, 2010

ACTIVITY SUMMARY (2010-10-08 - 2010-10-15) 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 stats: open 2554 (+34) closed 19344 (+63) total 21898 (+65) Open issues with patches: 1065 Issues opened (34) ================== #7140: imp.new_module does not function correctly if the module is re http://bugs.python.org/issue7140 reopened by benjamin.peterson #10052: Python/dtoa.c:158: #error "Failed to find an exact-width 32-bi http://bugs.python.org/issue10052 opened by akitada #10053: Don’t close fd when FileIO.__init__ fails http://bugs.python.org/issue10053 opened by ocean-city #10058: Unclear PyString_AsStringAndSize return value http://bugs.python.org/issue10058 opened by Nikratio #10060: python.exe crashes or hangs on help() modules when bad modules http://bugs.python.org/issue10060 opened by devplayer #10064: link to page with documentation bugs http://bugs.python.org/issue10064 opened by techtonik #10066: xmlrpclib does not handle some non-printable characters proper http://bugs.python.org/issue10066 opened by gyorkop #10070: 2to3 wishes for already-2to3'ed files http://bugs.python.org/issue10070 opened by hfuru #10071: Should not release GIL while running RegEnumValue http://bugs.python.org/issue10071 opened by ocean-city #10072: ftplib documentation is unclear http://bugs.python.org/issue10072 opened by rafe.kettler #10073: calendar.isleap() not checking parameter type http://bugs.python.org/issue10073 opened by shadikka #10076: Regex objects became uncopyable in 2.5 http://bugs.python.org/issue10076 opened by Michael.Shields #10077: Python 3.1: site error is not logged http://bugs.python.org/issue10077 opened by haypo #10079: idlelib for Python 3 with Guilherme Polo GSoC enhancements http://bugs.python.org/issue10079 opened by Bruce.Sherwood #10080: Py_Initialize crashes when stdout has been redirected with fre http://bugs.python.org/issue10080 opened by Mitchell.Stokes #10084: SSL support for asyncore http://bugs.python.org/issue10084 opened by pitrou #10086: test_sysconfig failure with site-packages http://bugs.python.org/issue10086 opened by hfuru #10087: HTML calendar is broken http://bugs.python.org/issue10087 opened by belopolsky #10089: Add support for arbitrary -X options http://bugs.python.org/issue10089 opened by pitrou #10090: python -m locale fails on OSX http://bugs.python.org/issue10090 opened by belopolsky #10092: calendar does not restore locale properly http://bugs.python.org/issue10092 opened by belopolsky #10093: Warn when files are not explicitly closed http://bugs.python.org/issue10093 opened by pitrou #10094: test_urllib.py fails in py3k r85440 with RuntimeError http://bugs.python.org/issue10094 opened by barry #10098: intermittent failure in test_os http://bugs.python.org/issue10098 opened by pitrou #10104: test_socket failures on Debian unstable http://bugs.python.org/issue10104 opened by pitrou #10107: Quitting IDLE on Mac doesn't save unsaved code http://bugs.python.org/issue10107 opened by Bruce.Sherwood #10108: ExpatError not property wrapped http://bugs.python.org/issue10108 opened by leos #10109: itertools.product with infinite iterator cause MemoryError. http://bugs.python.org/issue10109 opened by falsetru #10110: Queue doesn't recognize it is full after shrinking maxsize http://bugs.python.org/issue10110 opened by jaraco #10111: Minor problems with PyFileObject documentation (Doc/c-api/file http://bugs.python.org/issue10111 opened by pebolle #10112: Use -Wl,--dynamic-list=x.list, not -Xlinker -export-dynamic http://bugs.python.org/issue10112 opened by jankratochvil #10114: compile() doesn't support the PEP 383 (surrogates) http://bugs.python.org/issue10114 opened by haypo #10115: accept4 can fail with errno 90 http://bugs.python.org/issue10115 opened by pitrou #10116: Sporadic failures in test_urllibnet http://bugs.python.org/issue10116 opened by ixokai Most recent 15 issues with no replies (15) ========================================== #10114: compile() doesn't support the PEP 383 (surrogates) http://bugs.python.org/issue10114 #10112: Use -Wl,--dynamic-list=x.list, not -Xlinker -export-dynamic http://bugs.python.org/issue10112 #10111: Minor problems with PyFileObject documentation (Doc/c-api/file http://bugs.python.org/issue10111 #10110: Queue doesn't recognize it is full after shrinking maxsize http://bugs.python.org/issue10110 #10109: itertools.product with infinite iterator cause MemoryError. http://bugs.python.org/issue10109 #10092: calendar does not restore locale properly http://bugs.python.org/issue10092 #10090: python -m locale fails on OSX http://bugs.python.org/issue10090 #10077: Python 3.1: site error is not logged http://bugs.python.org/issue10077 #10064: link to page with documentation bugs http://bugs.python.org/issue10064 #10058: Unclear PyString_AsStringAndSize return value http://bugs.python.org/issue10058 #10051: distutils fail to install unicode-encoded files with POSIX loc http://bugs.python.org/issue10051 #10050: urllib.request still has old 2.x urllib primitives http://bugs.python.org/issue10050 #10048: urllib.request documentation confusing http://bugs.python.org/issue10048 #10037: multiprocessing.pool processes started by worker handler stops http://bugs.python.org/issue10037 #10036: compiler warnings for various modules on Ubuntu x86 http://bugs.python.org/issue10036 Most recent 15 issues waiting for review (15) ============================================= #10114: compile() doesn't support the PEP 383 (surrogates) http://bugs.python.org/issue10114 #10111: Minor problems with PyFileObject documentation (Doc/c-api/file http://bugs.python.org/issue10111 #10110: Queue doesn't recognize it is full after shrinking maxsize http://bugs.python.org/issue10110 #10093: Warn when files are not explicitly closed http://bugs.python.org/issue10093 #10089: Add support for arbitrary -X options http://bugs.python.org/issue10089 #10087: HTML calendar is broken http://bugs.python.org/issue10087 #10079: idlelib for Python 3 with Guilherme Polo GSoC enhancements http://bugs.python.org/issue10079 #10077: Python 3.1: site error is not logged http://bugs.python.org/issue10077 #10076: Regex objects became uncopyable in 2.5 http://bugs.python.org/issue10076 #10072: ftplib documentation is unclear http://bugs.python.org/issue10072 #10071: Should not release GIL while running RegEnumValue http://bugs.python.org/issue10071 #10066: xmlrpclib does not handle some non-printable characters proper http://bugs.python.org/issue10066 #10053: Don’t close fd when FileIO.__init__ fails http://bugs.python.org/issue10053 #10049: Add a "no-op" (null) context manager to contextlib http://bugs.python.org/issue10049 #10044: small int optimization http://bugs.python.org/issue10044 Top 10 most discussed issues (10) ================================= #8863: Display Python backtrace on SIGSEGV, SIGFPE and fatal error http://bugs.python.org/issue8863 16 msgs #10093: Warn when files are not explicitly closed http://bugs.python.org/issue10093 14 msgs #1553375: Add traceback.print_full_exception() http://bugs.python.org/issue1553375 14 msgs #10070: 2to3 wishes for already-2to3'ed files http://bugs.python.org/issue10070 11 msgs #10049: Add a "no-op" (null) context manager to contextlib http://bugs.python.org/issue10049 9 msgs #4388: test_cmd_line fails on MacOS X http://bugs.python.org/issue4388 8 msgs #10008: Two links point to same place http://bugs.python.org/issue10008 8 msgs #10089: Add support for arbitrary -X options http://bugs.python.org/issue10089 8 msgs #7944: Use the 'with' statement in conjunction with 'open' throughout http://bugs.python.org/issue7944 7 msgs #8998: add crypto routines to stdlib http://bugs.python.org/issue8998 7 msgs Issues closed (63) ================== #1051: certificate in Lib/test/test_ssl.py expires in February 2013 http://bugs.python.org/issue1051 closed by pitrou #1708: improvements for linecache http://bugs.python.org/issue1708 closed by r.david.murray #2830: Copy cgi.escape() to html http://bugs.python.org/issue2830 closed by georg.brandl #3865: explain that profilers should be used for profiling, not bench http://bugs.python.org/issue3865 closed by georg.brandl #5355: Expat parser error constants are string descriptions http://bugs.python.org/issue5355 closed by georg.brandl #6417: multiprocessing Process examples: print and getppid http://bugs.python.org/issue6417 closed by georg.brandl #6825: Minor documentation bug with os.path.split http://bugs.python.org/issue6825 closed by georg.brandl #7285: multiprocessing module, example code error http://bugs.python.org/issue7285 closed by orsenthil #7287: import hook demo does not work http://bugs.python.org/issue7287 closed by benjamin.peterson #7516: Flag "-3" is silently ignored when running "regrtest.py -j2" http://bugs.python.org/issue7516 closed by pitrou #7523: add SOCK_NONBLOCK and SOCK_CLOEXEC to socket module http://bugs.python.org/issue7523 closed by pitrou #7642: Minor improvement to os.system doc http://bugs.python.org/issue7642 closed by georg.brandl #7771: dict view comparison methods are not documented http://bugs.python.org/issue7771 closed by georg.brandl #8267: Tutorial section on dictionary keys recommends sort instead of http://bugs.python.org/issue8267 closed by georg.brandl #9003: urllib.request and http.client should allow certificate checki http://bugs.python.org/issue9003 closed by pitrou #9013: Implement tzinfo.dst() method in timezone http://bugs.python.org/issue9013 closed by belopolsky #9093: Tools/README is out of date http://bugs.python.org/issue9093 closed by georg.brandl #9183: Intern UTC timezone http://bugs.python.org/issue9183 closed by belopolsky #9409: doctest in python2.7 can't handle non-ascii characters http://bugs.python.org/issue9409 closed by flox #9774: test_smtpnet fails with "[110] Connection timed out" on AMD64 http://bugs.python.org/issue9774 closed by pitrou #9964: Test failures with -OO http://bugs.python.org/issue9964 closed by georg.brandl #9988: test_warnings fails with PYTHONFSENCODING=latin-1 on UNIX/BSD http://bugs.python.org/issue9988 closed by haypo #9992: Command-line arguments are not correctly decoded if locale and http://bugs.python.org/issue9992 closed by haypo #10011: `except` doesn't use `isinstance` http://bugs.python.org/issue10011 closed by terry.reedy #10014: sys.path[0] is incorrect if PYTHONFSENCODING is used http://bugs.python.org/issue10014 closed by haypo #10018: IDLE not loading in xp pro due to tcl issue http://bugs.python.org/issue10018 closed by terry.reedy #10029: "Equivalent to" code for zip is wrong in Python 3 http://bugs.python.org/issue10029 closed by rhettinger #10039: python é.py fails with UnicodeEncodeError if PYTHONFSENCODING http://bugs.python.org/issue10039 closed by haypo #10045: poor cStringIO.StringO seek performance http://bugs.python.org/issue10045 closed by fdrake #10046: Correction to atexit documentation http://bugs.python.org/issue10046 closed by georg.brandl #10054: select extension does not build on platforms where uintptr_t i http://bugs.python.org/issue10054 closed by pitrou #10055: C99 code in _json.c http://bugs.python.org/issue10055 closed by pitrou #10056: Can't build tkinter with libtk 8.6 http://bugs.python.org/issue10056 closed by pitrou #10057: Unclear if exception should be set http://bugs.python.org/issue10057 closed by jankratochvil #10059: add the method `index` to collections.deque http://bugs.python.org/issue10059 closed by Simon.Liedtke #10061: ** operator yielding wrong result for negative numbers http://bugs.python.org/issue10061 closed by orsenthil #10062: Python 3.2 does not build on systems which do not have sem_tim http://bugs.python.org/issue10062 closed by pitrou #10065: future_builtins' docstring lacks some functions http://bugs.python.org/issue10065 closed by orsenthil #10067: itertools' docs put izip_longest in the "terminating on the sh http://bugs.python.org/issue10067 closed by rhettinger #10068: global objects created in some module are not destroyed when l http://bugs.python.org/issue10068 closed by benjamin.peterson #10069: 2to3 crash in fix_urllib.py http://bugs.python.org/issue10069 closed by benjamin.peterson #10074: dictobject.c: crash in Py_XDECREF http://bugs.python.org/issue10074 closed by benjamin.peterson #10075: Get session cache stats from SSLContext http://bugs.python.org/issue10075 closed by pitrou #10078: Documentation: 'Postive' should be 'Positive' http://bugs.python.org/issue10078 closed by benjamin.peterson #10081: 'import' operator doesn't work with unicode non 7-bit ASCII mo http://bugs.python.org/issue10081 closed by brett.cannon #10082: PyRun_SimpleFile crashes application http://bugs.python.org/issue10082 closed by loewis #10083: locale.currency() uses different formatting than system locale http://bugs.python.org/issue10083 closed by eric.smith #10085: Memory allocation for primitive types http://bugs.python.org/issue10085 closed by pitrou #10088: pdb can't re-set variables http://bugs.python.org/issue10088 closed by giampaolo.rodola #10091: ast.literal_eval does not handled new set literals http://bugs.python.org/issue10091 closed by georg.brandl #10095: Support undecodable filenames in the parser API http://bugs.python.org/issue10095 closed by haypo #10096: Question regarding python migration http://bugs.python.org/issue10096 closed by orsenthil #10097: platform.uname gives UnicodeError for non-ASCII computer names http://bugs.python.org/issue10097 closed by lemburg #10099: socket.fromfd() documentation problem http://bugs.python.org/issue10099 closed by orsenthil #10100: fromfd is now available on all platforms http://bugs.python.org/issue10100 closed by orsenthil #10101: a bug in built-in function round() ? http://bugs.python.org/issue10101 closed by benjamin.peterson #10102: mktime adding an hour in April (naive struct)? http://bugs.python.org/issue10102 closed by belopolsky #10103: use the SOABI for GNU/kfreeBSD and the GNU Hurd http://bugs.python.org/issue10103 closed by doko #10105: Strings failing to print http://bugs.python.org/issue10105 closed by eric.araujo #10106: missing packages http://bugs.python.org/issue10106 closed by brett.cannon #10113: UnicodeDecodeError in mimetypes.guess_type on Windows http://bugs.python.org/issue10113 closed by r.david.murray #1710703: zipfile.ZipFile behavior inconsistent. http://bugs.python.org/issue1710703 closed by georg.brandl #10063: file:// scheme will stop accessing via ftp protocol http://bugs.python.org/issue10063 closed by orsenthil

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Issue 10094
by Barry Warsaw Oct. 15, 2010

Oct. 15, 2010

Posting this here first, though it's looking less like a Python bug and more like an environment problem, or issue with something in Ubuntu. I'm running the regular test suite for the py3k branch and seeing this failure on Ubuntu 10.10: http://bugs.python.org/issue10094 test_urllib.py fails with RuntimeError on Ubuntu 10.10 It's completely consistent. It happens with the regular test suite, or just running test_urllib.py, and it does not happen with any other test afaict. I've gone way back in svn, pulled down earlier alphas that I know worked and they all exhibit the bug. This only happens on Ubuntu 10.10 machines (afaict so far), both i386 and x86_64. It does not happen on Ubuntu 10.04 64bit VMs, nor does it happen on Debian squeeze. I'll continue to investigate, but since it's damn perplexing I just wanted to see if anybody had any thoughts on the problem. Cheers, -Barry

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Re: [Python-Dev] [Python-checkins] r85486 - python/branches/py3k/configure
by Daniel Stutzbach Oct. 14, 2010

Oct. 14, 2010

On Thu, Oct 14, 2010 at 12:38 PM, barry.warsaw <python-checkins(a)python.org>wrote: > -# Generated by GNU Autoconf 2.65 for python 3.2. > +# Generated by GNU Autoconf 2.67 for python 3.2. > Was the change in autoconf versions intentional and/or is it a problem? -- Daniel Stutzbach, Ph.D. President, Stutzbach Enterprises, LLC <http://stutzbachenterprises.com/>

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Re: [Python-Dev] [Python-checkins] r85481 - in python/branches/py3k: Misc/NEWS configure.in
by Brett Cannon Oct. 14, 2010

Oct. 14, 2010

Doesn't autoconf need to be run to regenerate configure? On Thu, Oct 14, 2010 at 08:24, matthias.klose <python-checkins(a)python.org> wrote: > Author: matthias.klose > Date: Thu Oct 14 17:24:22 2010 > New Revision: 85481 > > Log: > - Issue #10094: Use versioned .so files on GNU/kfreeBSD and the GNU Hurd. > > > Modified: > python/branches/py3k/Misc/NEWS > python/branches/py3k/configure.in > > Modified: python/branches/py3k/Misc/NEWS > ============================================================================== > --- python/branches/py3k/Misc/NEWS (original) > +++ python/branches/py3k/Misc/NEWS Thu Oct 14 17:24:22 2010 > @@ -61,6 +61,11 @@ > > - Issue #7287: Demo/imputil/knee.py was removed. > > +Build > +----- > + > +- Issue #10094: Use versioned .so files on GNU/kfreeBSD and the GNU Hurd. > + > > What's New in Python 3.2 Alpha 3? > ================================= > > Modified: python/branches/py3k/configure.in > ============================================================================== > --- python/branches/py3k/configure.in (original) > +++ python/branches/py3k/configure.in Thu Oct 14 17:24:22 2010 > @@ -3652,7 +3652,8 @@ > esac > ;; > CYGWIN*) SO=.dll;; > - Linux*) SO=.${SOABI}.so;; > + Linux*|GNU*) > + SO=.${SOABI}.so;; > *) SO=.so;; > esac > else > _______________________________________________ > Python-checkins mailing list > Python-checkins(a)python.org > http://mail.python.org/mailman/listinfo/python-checkins >

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Re: [Python-Dev] [Python-checkins] r85463 - python/branches/py3k/Lib/test/test_import.py
by Barry Warsaw Oct. 14, 2010

Oct. 14, 2010

On Oct 14, 2010, at 09:34 AM, georg.brandl wrote: >Author: georg.brandl >Date: Thu Oct 14 09:34:56 2010 >New Revision: 85463 > >Log: >Better check for "any optimize option given". > >Modified: > python/branches/py3k/Lib/test/test_import.py > >Modified: python/branches/py3k/Lib/test/test_import.py >============================================================================== >--- python/branches/py3k/Lib/test/test_import.py (original) >+++ python/branches/py3k/Lib/test/test_import.py Thu Oct 14 09:34:56 2010 >@@ -521,7 +521,7 @@ > self.assertTrue(os.path.exists('__pycache__')) > self.assertTrue(os.path.exists(os.path.join( > '__pycache__', '{}.{}.py{}'.format( >- TESTFN, self.tag, sys.flags.optimize and 'o' or 'c')))) >+ TESTFN, self.tag, __debug__ and 'c' or 'o')))) You might want to use imp.cache_from_source() instead for consistency. > > @unittest.skipUnless(os.name == 'posix', > "test meaningful only on posix systems") -Barry

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socket.fromfd() documentation problem
by Kálmán Gergely Oct. 14, 2010

Oct. 14, 2010

Hello I was having a very nasty fd leak recently where I've leaked more than 200k FDs, allocating more than 1Gbytes of ram in kernel space. It was my fault alright, but I thought I'd mention it here so maybe you'll put a little NOTE section in the documentation mentioning that you have to os.close() the original FD to avoid leakage. Also I'm not completely clear why python does it this way and why not close the original socket - it seems (at least to me) that this would be the right(er) way. Nevertheless what are your thoughts on this? Should I file a bug report for it? (The best part was that the allocated FD memory did not show up as slab, so this was a real pain in the butt to hunt down) Kalman Gergely

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Add aware local time support to datetime module
by Alexander Belopolsky Oct. 13, 2010

Oct. 13, 2010

[I've got no response from python-ideas, so I am forwarding to python-dev.] With addition of fixed offset timezone class and the timezone.utc instance [0], it is easy to get UTC time as an aware datetime instance: >>> datetime.now(timezone.utc) datetime.datetime(2010, 8, 3, 14, 16, 10, 670308, tzinfo=datetime.timezone.utc) However, if you want to keep time in your local timezone, getting an aware datetime is almost a catch 22. If you know your timezone UTC offset, you can do >>> EDT = timezone(timedelta(hours=-4)) >>> datetime.now(EDT) datetime.datetime(2010, 8, 3, 10, 20, 23, 769537, tzinfo=datetime.timezone(datetime.timedelta(-1, 72000))) but the problem is that there is no obvious or even correct way to find local timezone UTC offset. [1] In a comment on issue #5094 ("datetime lacks concrete tzinfo implementation for UTC"), I proposed to address this problem in a localtime([t]) function that would return current time (or time corresponding to the optional datetime argument) as an aware datetime object carrying local timezone information in a tzinfo set to an appropriate timezone instance. This solution is attractive by its simplicity, but there are several problems: 1. An aware datetime cannot carry all information that system localtime() supplies in a time tuple. Specifically, the is_dst flag is lost. This is not a problem for most applications as long as timezone UTC offset and timezone name are available, but may be an issue when interoperability with the time module is required. 2. Datetime's tzinfo interface was designed with the idea that <2010-11-06 12:00 EDT> + <1 day> = <2010-11-07 12:00 EST>, not <2010-11-07 12:00 EDT>. It other words, if I have lunch with someone at noon (12:00 EDT) on Saturday the day before first Sunday in November, and want to meet again "at the same time tomorrow", I mean 12:00 EST, not 24 hours later. With localtime() returning datetime with tzinfo set to fixed offset timezone, however, localtime() + timedelta(1) will mean exactly 24 hours later and the result will be expressed in an unusual for the given location timezone. An alternative approach is the one recommended in the python manual. [3] One could implement a LocalTimezone class with utcoffset(), tzname() and dst() extracting information from system mktime and localtime calls. This approach has its own shortcomings: 1. While adding integral number of days to datetimes in business setting, it is natural to expect automatic timezone adjustments, it is not as clearcut when adding hours or minutes. 2. The tzinfo.utcoffset() interface that expects *standard* local time as an argument is confusing to many users. Even the "official" example in the python manual gets it wrong. [4] 3. datetime(..., tzinfo=LocalTimezone()) is ambiguous during the "repeated hour" when local clock is set back in DST to standard time transition. As far as I can tell, the only way to resolve the last problem is to add is_dst flag to the datetime object, which would also be the only way to achieve full interoperability between datetime objects and time tuples. [5] The traditional answer to call for improvement of timezone support in datetime module has been: "this is upto 3rd parties to implement." Unfortunately, stdlib is asking 3rd parties to implement an impossible interface without giving access to the necessary data. The impossibility comes from the requirement that dst() method should find out whether local time represents DST or standard time while there is an hour each year when the same local time can be either. The missing data is the system UTC offset when it changes historically. The time module only gives access to the current UTC offset. My preference is to implement the first alternative - localtime([t]) returning aware datetime with fixed offset timezone. This will solve the problem of python's lack of access to the universally available system facilities that are necessary to implement any kind of aware local time support. [0] http://docs.python.org/dev/library/datetime.html#timezone-objects [1] http://bugs.python.org/issue1647654 [2] http://bugs.python.org/issue5094#msg106997 [3] http://docs.python.org/library/datetime.html#tzinfo-objects [4] http://bugs.python.org/issue9063 [5] http://bugs.python.org/issue9004

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