Mailman 3 April 2009 - Python-Dev

Windows buildbots failing test_types in trunk
by Eric Smith 27 Apr '09

27 Apr '09

Mark Dickinson pointed out to me that the trunk buildbots are failing under Windows. After some analysis, I think this is because of a change I made to use _toupper in integer formatting. The correct solution to this is to implement issue 5793 to come up with a working, cross-platform, locale-unaware set of functions and/or macros for isdigit / isupper / toupper, etc. I'll work on this tonight or tomorrow, at which point the Windows buildbots should turn green. I don't think this affects py3k, although I'll port it there before the beta release. Eric.

1 0

Two proposed changes to float formatting
by Mark Dickinson 27 Apr '09

27 Apr '09

I'd like to propose two minor changes to float and complex formatting, for 3.1. I don't think either change should prove particularly disruptive. (1) Currently, '%f' formatting automatically changes to '%g' formatting for numbers larger than 1e50. For example: >>> '%f' % 2**166. '93536104789177786765035829293842113257979682750464.000000' >>> '%f' % 2**167. '1.87072e+50' I propose removing this feature for 3.1 More details: The current behaviour is documented (standard library->builtin types). (Until very recently, it was actually misdocumented as changing at 1e25, not 1e50.) """For safety reasons, floating point precisions are clipped to 50; %f conversions for numbers whose absolute value is over 1e50 are replaced by %g conversions. [5] All other errors raise exceptions.""" There's even a footnote: """[5] These numbers are fairly arbitrary. They are intended to avoid printing endless strings of meaningless digits without hampering correct use and without having to know the exact precision of floating point values on a particular machine.""" I don't find this particularly convincing, though---I just don't see a really good reason not to give the user exactly what she/he asks for here. I have a suspicion that at least part of the motivation for the '%f' -> '%g' switch is that it means the implementation can use a fixed-size buffer. But Eric has fixed this (in 3.1, at least) and the buffer is now dynamically allocated, so this isn't a concern any more. Other reasons not to switch from '%f' to '%g' in this way: - the change isn't gentle: as you go over the 1e50 boundary, the number of significant digits produced suddenly changes from 56 to 6; it would make more sense to me if it stayed fixed at 56 sig digits for numbers larger than 1e50. - now that we're using David Gay's 'perfect rounding' code, we can be sure that the digits aren't entirely meaningless, or at least that they're the 'right' meaningless digits. This wasn't true before. - C doesn't do this, and the %f, %g, %e formats really owe their heritage to C. - float formatting is already quite complicated enough; no need to add to the mental complexity - removal simplifies the implementation :-) On to the second proposed change: (2) complex str and repr don't behave like float str and repr, in that the float version always adds a trailing '.0' (unless there's an exponent), but the complex version doesn't: >>> 4., 10. (4.0, 10.0) >>> 4. + 10.j (4+10j) I propose changing the complex str and repr to behave like the float version. That is, repr(4. + 10.j) should be "(4.0 + 10.0j)" rather than "(4+10j)". Mostly this is just about consistency, ease of implementation, and aesthetics. As far as I can tell, the extra '.0' in the float repr serves two closely-related purposes: it makes it clear to the human reader that the number is a float rather than an integer, and it makes sure that e.g., eval(repr(x)) recovers a float rather than an int. The latter point isn't a concern for the current complex repr, but the former is: 4+10j looks to me more like a Gaussian integer than a complex number. Any comments? Mark

7 12

float formatting
by Dennis Allison 26 Apr '09

26 Apr '09

Floating point printing is tricky, as I am sure you know. You might want to refrefresh your understanding by consulting the literture--I know I would. For example, you might want to look at http://portal.acm.org/citation.cfm?id=93559 Guy Steele's paper: Guy L. Steele , Jon L. White, How to print floating-point numbers accurately, ACM SIGPLAN Notices, v.39 n.4, April 2004 is a classic and worthy of a read.

1 0

Bug tracker down?
by Mark Dickinson 26 Apr '09

26 Apr '09

The bugs.python.org site seems to be down. ping gives me the following (from Ireland): Macintosh-4:py3k dickinsm$ ping bugs.python.org PING bugs.python.org (88.198.142.26): 56 data bytes 36 bytes from et.2.16.rs3k6.rz5.hetzner.de (213.239.244.101): Destination Host Unreachable Vr HL TOS Len ID Flg off TTL Pro cks Src Dst 4 5 00 5400 77e1 0 0000 3a 01 603d 192.168.1.2 88.198.142.26 Various others on #python-dev have confirmed that it's not working for them. Does anyone know what the problem is? Mark

3 4

Re: [Python-Dev] [Python-checkins] r71946 - peps/trunk/pep-0315.txt
by Eric Smith 26 Apr '09

26 Apr '09

You might want to note in the PEP that the problem that's being solved is known as the "loop and a half" problem. http://www.cs.duke.edu/~ola/patterns/plopd/loops.html#loop-and-a-half raymond.hettinger wrote: > Author: raymond.hettinger > Date: Sun Apr 26 02:34:36 2009 > New Revision: 71946 > > Log: > Revive PEP 315. > > Modified: > peps/trunk/pep-0315.txt > > Modified: peps/trunk/pep-0315.txt > ============================================================================== > --- peps/trunk/pep-0315.txt (original) > +++ peps/trunk/pep-0315.txt Sun Apr 26 02:34:36 2009 > @@ -2,9 +2,9 @@ > Title: Enhanced While Loop > Version: $Revision$ > Last-Modified: $Date$ > -Author: W Isaac Carroll <icarroll(a)pobox.com> > - Raymond Hettinger <python(a)rcn.com> > -Status: Deferred > +Author: Raymond Hettinger <python(a)rcn.com> > + W Isaac Carroll <icarroll(a)pobox.com> > +Status: Draft > Type: Standards Track > Content-Type: text/plain > Created: 25-Apr-2003 > _______________________________________________ > Python-checkins mailing list > Python-checkins(a)python.org > http://mail.python.org/mailman/listinfo/python-checkins >

1 0

Deprecating PyOS_ascii_formatd
by Eric Smith 25 Apr '09

25 Apr '09

Assuming that Mark's and my changes in the py3k-short-float-repr branch get checked in shortly, I'd like to deprecate PyOS_ascii_formatd. Its functionality is largely being replaced by PyOS_double_to_string, which we're introducing on our branch. PyOS_ascii_formatd was introduced to fix the issue in PEP 331. PyOS_double_to_string addresses all of the same issues, namely a non-locale aware double-to-string conversion. PyOS_ascii_formatd has an unfortunate interface. It accepts a printf-like format string for a single double parameter. It must parse the format string into the parameters it uses. All uses of it inside Python already know the parameters and must build up a format string using sprintf, only to turn around and have PyOS_ascii_formatd reparse it. In the branch I've replaced all of the internal calls to PyOS_ascii_format with PyOS_double_to_string. My proposal is to deprecate PyOS_ascii_formatd in 3.1 and remove it in 3.2. The 2.7 situation is tricker, because we're not planning on backporting the short-float-repr work back to 2.7. In 2.7 I guess we'll leave PyOS_ascii_formatd around, unfortunately. FWIW, I didn't find any external callers of it using Google code search. And as a reminder, the py3k-short-float-repr changes are on Rietveld at http://codereview.appspot.com/33084/show. So far, no comments.

3 5

Tuples and underorderable types
by Raymond Hettinger 25 Apr '09

25 Apr '09

Does anyone have any ideas about what to do with issue 5830 and handling the problem in a general way (not just for sched)? The basic problem is that decorate/compare/undecorate patterns no longer work when the primary sort keys are equal and the secondary keys are unorderable (which is now the case for many callables). >>> tasks = [(10, lambda: 0), (20, lambda: 1), (10, lambda: 2)] >>> tasks.sort() Traceback (most recent call last): ... TypeError: unorderable types: function() < function() Would it make sense to provide a default ordering whenever the types are the same? def object.__lt__(self, other): if type(self) == type(other): return id(self) < id(other) raise TypeError Raymond

7 9

"Length of str " changes after passed in Python 2.5
by Leo.Barendse＠nokia.com 24 Apr '09

24 Apr '09

----------------------------------------------------------- I have the following code: # len(all_svs) = 10 # the I call a function with 2 list parameters def proc_line(line,all_svs) : # inside the function the length of the list "all_svs" is 1 more -> 11 # I had to workaround it for i in range(len(all_svs) - 1 ) : # some how the length of all_svs is incremented !!!!!!!!!!!!!!!!!!!!!!!!!!! -------------------------------------------------------------- Is this a compiler bug ?? Or is it because of my first try of Python Thanks

2 1

Summary of Python tracker Issues
by Python tracker 24 Apr '09

24 Apr '09

ACTIVITY SUMMARY (04/17/09 - 04/24/09) 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. 2227 open (+32) / 15427 closed (+17) / 17654 total (+49) Open issues with patches: 865 Average duration of open issues: 641 days. Median duration of open issues: 395 days. Open Issues Breakdown open 2175 (+31) pending 52 ( +1) Issues Created Or Reopened (51) _______________________________ Builtin round function is sometimes inaccurate for floats 04/18/09 CLOSED http://bugs.python.org/issue1869 reopened marketdickinson patch logging to file + encoding 04/20/09 CLOSED http://bugs.python.org/issue5170 reopened shamilbi IDLE cannot find windows chm file 04/17/09 http://bugs.python.org/issue5783 created rhettinger patch raw deflate format and zlib module 04/17/09 http://bugs.python.org/issue5784 created phr Condition.wait() does not respect its timeout 04/18/09 CLOSED http://bugs.python.org/issue5785 created Kjir len(reversed([1,2,3])) does not work anymore in 2.6.2 04/19/09 http://bugs.python.org/issue5786 reopened rhettinger object.__getattribute__(super, '__bases__') crashes the interpre 04/19/09 CLOSED http://bugs.python.org/issue5787 reopened alexer datetime.timedelta is inconvenient to use... 04/18/09 http://bugs.python.org/issue5788 created bquinlan patch powerset recipe listed twice in itertools docs 04/19/09 CLOSED http://bugs.python.org/issue5789 created stevenjd easy itertools.izip python code has a typo 04/19/09 CLOSED http://bugs.python.org/issue5790 created stevenjd title information of unicodedata is wrong in some cases 04/19/09 CLOSED http://bugs.python.org/issue5791 created cfbolz Enable short float repr() on Solaris/x86 04/19/09 http://bugs.python.org/issue5792 created marketdickinson easy Rationalize isdigit / isalpha / tolower / ... uses throughout Py 04/19/09 http://bugs.python.org/issue5793 created marketdickinson easy pickle/cPickle of recursive tuples create pickles that cPickle c 04/19/09 http://bugs.python.org/issue5794 created cwitty test_distutils failure on the ppc Debian buildbot 04/19/09 CLOSED http://bugs.python.org/issue5795 created pitrou test_posix, test_pty crash under Windows 04/19/09 CLOSED http://bugs.python.org/issue5796 created pitrou patch there is en exception om Create User page 04/20/09 http://bugs.python.org/issue5797 created nabeel test_asynchat fails on Mac OSX 04/20/09 http://bugs.python.org/issue5798 created cartman Change ntpath functions to implicitly support UNC paths 04/20/09 http://bugs.python.org/issue5799 created larry patch make wsgiref.headers.Headers accept empty constructor 04/20/09 http://bugs.python.org/issue5800 created tarek easy spurious empty lines in wsgiref code 04/20/09 http://bugs.python.org/issue5801 created tarek The security descriptors of python binaries in Windows are not s 04/20/09 http://bugs.python.org/issue5802 created kindloaf email/quoprimime: encode and decode are very slow on large messa 04/20/09 http://bugs.python.org/issue5803 created dmbaggett Add a "tail" argument to zlib.decompress 04/21/09 http://bugs.python.org/issue5804 created krisvale patch Distutils (or py2exe) error with DistributionMetaData 04/21/09 CLOSED http://bugs.python.org/issue5805 created varash MySQL crash on machine startup.... 04/21/09 CLOSED http://bugs.python.org/issue5806 created plattecoducks ConfigParser.RawConfigParser it's an "old-style" class 04/21/09 CLOSED http://bugs.python.org/issue5807 created ZeD Subprocess.getstatusoutput Fails Executing 'dir' Command on Wind 04/21/09 CLOSED http://bugs.python.org/issue5808 created mrwizard82d1 "No such file or directory" with framework build under MacOS 10. 04/21/09 http://bugs.python.org/issue5809 created creachadair test_distutils fails - sysconfig._config_vars is None 04/22/09 http://bugs.python.org/issue5810 created srid io.BufferedReader.peek(): Documentation differs from Implementat 04/22/09 http://bugs.python.org/issue5811 created trott Fraction('1e6') should be valid. 04/22/09 CLOSED http://bugs.python.org/issue5812 created marketdickinson patch Pointer into language reference from __future__ module documenta 04/22/09 CLOSED http://bugs.python.org/issue5813 created ncoghlan SocketServer: TypeError: waitpid() takes no keyword arguments 04/22/09 http://bugs.python.org/issue5814 created arekm locale.getdefaultlocale() missing corner case 04/22/09 http://bugs.python.org/issue5815 created rg3 patch Simplify parsing of complex numbers and make complex('inf') vali 04/22/09 CLOSED http://bugs.python.org/issue5816 created marketdickinson patch Right-click behavior from Windows Explorer 04/23/09 http://bugs.python.org/issue5817 created Mkop Fix five small bugs in the bininstall and altbininstall pseudota 04/23/09 http://bugs.python.org/issue5818 created larry patch Add PYTHONPREFIXES environment variable 04/23/09 http://bugs.python.org/issue5819 created larry patch Very small bug in documentation of json.load() 04/23/09 CLOSED http://bugs.python.org/issue5820 created pcshyamshankar patch Documentation: mention 'close' and iteration for tarfile.TarFile 04/23/09 http://bugs.python.org/issue5821 created bennorth patch inconsistent behavior of range when used in combination with rem 04/23/09 CLOSED http://bugs.python.org/issue5822 created zero79 feature request: a conditional "for" statement 04/23/09 CLOSED http://bugs.python.org/issue5823 created zero79 SocketServer.DatagramRequestHandler Broken under Linux 04/23/09 http://bugs.python.org/issue5824 created jimd Patch to add "remove" method to tempfile.NamedTemporaryFile 04/24/09 http://bugs.python.org/issue5825 created tebeka patch new unittest function listed as assertIsNotNot() instead of asse 04/24/09 http://bugs.python.org/issue5826 created mrooney os.path.normpath doesn't preserve unicode 04/24/09 http://bugs.python.org/issue5827 created mgiuca patch Invalid behavior of unicode.lower 04/24/09 http://bugs.python.org/issue5828 created jarek float('1e500') -> inf, complex('1e500') -> ValueError 04/24/09 http://bugs.python.org/issue5829 created marketdickinson easy heapq item comparison problematic with sched's events 04/24/09 http://bugs.python.org/issue5830 created kfj Doc mistake : threading.Timer is *not* a class 04/24/09 http://bugs.python.org/issue5831 created maxenced easy Issues Now Closed (50) ______________________ Use shorter float repr when possible 495 days http://bugs.python.org/issue1580 marketdickinson patch Builtin round function is sometimes inaccurate for floats 0 days http://bugs.python.org/issue1869 marketdickinson patch Idle, some Linuxes, cannot position Cursor by mouseclick 329 days http://bugs.python.org/issue2995 gpolo Make conversions from long to float correctly rounded. 303 days http://bugs.python.org/issue3166 marketdickinson patch Exception for test_urllib2_localnet 246 days http://bugs.python.org/issue3584 r.david.murray float.fromhex discrepancy under Solaris 240 days http://bugs.python.org/issue3633 marketdickinson patch, needs review patch for review: OS/2 EMX port fixes for 2.6 221 days http://bugs.python.org/issue3868 aimacintyre patch, patch logging to file + encoding 2 days http://bugs.python.org/issue5170 vsajip Allow auto-numbered replacement fields in str.format() strings 68 days http://bugs.python.org/issue5237 eric.smith patch Add test.support.import_python_only 58 days http://bugs.python.org/issue5354 ncoghlan 'n' formatting for int and float handles leading zero padding po 35 days http://bugs.python.org/issue5515 eric.smith bad repr of itertools.count object with negative value on OS X 1 18 days http://bugs.python.org/issue5657 ronaldoussoren Fix BufferedRWPair 8 days http://bugs.python.org/issue5734 pitrou patch Typo in documentation of print function parameters 7 days http://bugs.python.org/issue5751 georg.brandl Documentation error for Condition.notify() 7 days http://bugs.python.org/issue5757 georg.brandl __getitem__ error message hard to understand 3 days http://bugs.python.org/issue5760 georg.brandl SA bugs with unittest.py@r71263 2 days http://bugs.python.org/issue5771 benjamin.peterson patch For float.__format__, don't add a trailing ".0" if we're using n 6 days http://bugs.python.org/issue5772 eric.smith easy marshal.c needs to be checked for out of memory errors 5 days http://bugs.python.org/issue5775 eric.smith unable to search in python V3 documentation 1 days http://bugs.python.org/issue5777 georg.brandl _elementtree import can fail silently 1 days http://bugs.python.org/issue5779 benjamin.peterson test_float fails for 'legacy' float repr style 1 days http://bugs.python.org/issue5780 marketdickinson patch Legacy float repr is used unnecessarily on some platforms 1 days http://bugs.python.org/issue5781 marketdickinson easy ',' formatting with empty format type '' (PEP 378) 5 days http://bugs.python.org/issue5782 eric.smith easy Condition.wait() does not respect its timeout 1 days http://bugs.python.org/issue5785 benjamin.peterson object.__getattribute__(super, '__bases__') crashes the interpre 0 days http://bugs.python.org/issue5787 benjamin.peterson powerset recipe listed twice in itertools docs 3 days http://bugs.python.org/issue5789 rhettinger easy itertools.izip python code has a typo 2 days http://bugs.python.org/issue5790 rhettinger title information of unicodedata is wrong in some cases 0 days http://bugs.python.org/issue5791 loewis test_distutils failure on the ppc Debian buildbot 1 days http://bugs.python.org/issue5795 tarek test_posix, test_pty crash under Windows 2 days http://bugs.python.org/issue5796 r.david.murray patch Distutils (or py2exe) error with DistributionMetaData 0 days http://bugs.python.org/issue5805 loewis MySQL crash on machine startup.... 0 days http://bugs.python.org/issue5806 plattecoducks ConfigParser.RawConfigParser it's an "old-style" class 0 days http://bugs.python.org/issue5807 benjamin.peterson Subprocess.getstatusoutput Fails Executing 'dir' Command on Wind 0 days http://bugs.python.org/issue5808 benjamin.peterson Fraction('1e6') should be valid. 2 days http://bugs.python.org/issue5812 marketdickinson patch Pointer into language reference from __future__ module documenta 1 days http://bugs.python.org/issue5813 georg.brandl Simplify parsing of complex numbers and make complex('inf') vali 2 days http://bugs.python.org/issue5816 marketdickinson patch Very small bug in documentation of json.load() 0 days http://bugs.python.org/issue5820 georg.brandl patch inconsistent behavior of range when used in combination with rem 0 days http://bugs.python.org/issue5822 zero79 feature request: a conditional "for" statement 0 days http://bugs.python.org/issue5823 zero79 No sleep or busy wait 2093 days http://bugs.python.org/issue780602 gpolo ConfigParser non-string defaults broken with .getboolean() 1771 days http://bugs.python.org/issue974019 draghuram patch, easy ctrl-left/-right works incorectly with diacritics 1707 days http://bugs.python.org/issue1012435 gpolo not enough information in SGMLParseError 1625 days http://bugs.python.org/issue1063229 ajaksu2 Frame does not receive configure event on move 1562 days http://bugs.python.org/issue1100366 gpolo Let shift operators take any integer value 1436 days http://bugs.python.org/issue1205239 marketdickinson Allow thread(ing) tests to pass without setting stack size 994 days http://bugs.python.org/issue1533520 aimacintyre patch import deadlocks when using PyObjC threads 898 days http://bugs.python.org/issue1590864 abaron object.__init__ shouldn't allow args/kwds 763 days http://bugs.python.org/issue1683368 KayEss Top Issues Most Discussed (10) ______________________________ 18 Add DTrace probes 194 days open http://bugs.python.org/issue4111 15 IDLE cannot find windows chm file 7 days pending http://bugs.python.org/issue5783 9 len(reversed([1,2,3])) does not work anymore in 2.6.2 6 days open http://bugs.python.org/issue5786 8 Use shorter float repr when possible 495 days closed http://bugs.python.org/issue1580 7 Fraction('1e6') should be valid. 2 days closed http://bugs.python.org/issue5812 7 datetime.timedelta is inconvenient to use... 6 days open http://bugs.python.org/issue5788 7 logging to file + encoding 2 days closed http://bugs.python.org/issue5170 7 Builtin round function is sometimes inaccurate for floats 0 days closed http://bugs.python.org/issue1869 6 Simplify parsing of complex numbers and make complex('inf') val 2 days closed http://bugs.python.org/issue5816 6 locale.getdefaultlocale() missing corner case 2 days open http://bugs.python.org/issue5815

4 3

Dates in python-dev
by MRAB 24 Apr '09

24 Apr '09

Hi, I've recently subscribed to this list and received my first "Summary of Python tracker Issues". What I find annoying are the dates, for example: ACTIVITY SUMMARY (04/17/09 - 04/24/09) 3 x double-digits (have we learned nothing from Y2K? :-)) with the _middle_ ones changing fastest! I know it's the US standard, but Python is global. Could we have an 'international' style instead, say, year-month-day: ACTIVITY SUMMARY (2009-04-17 - 2009-04-24) Thank you for your attention, etc.

6 5