Mailman 3 February 2008 - Python-Dev

Re: [Python-Dev] Different float formatting on Windows and Linux
by Ralf W. Grosse-Kunstleve 19 Feb '08

19 Feb '08

> The tests for float.__format__ are breaking on Windows, because of this > issue: http://bugs.python.org/issue1600. Basically, Windows is using 3 > digits for exponents < 100, and Linux (and at least MacOS) are using 2. Yes, this is very annoying and I once lost of lot of time because of the Windows difference. > I think the options are: > 1: Do nothing. Adapt the tests to deal with the differences. > 2: Force 3 characters for exponents < 100. > 3: Force 2 characters for exponents < 100. I'd go for 3. Rationale: this change will mostly affect scientific code, which is mostly developed and used on Unix systems. Thanks for taking care if this nuisance! Ralf

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Py_CLEAR to avoid crashes
by Amaury Forgeot d'Arc 19 Feb '08

19 Feb '08

Hello, I think I found a prolific vein of potential crashes throughout the python interpreter. The idea is inspired from the discussion Issue1020188 and is quite simple: find a Py_DECREF(xxx->yyy), where xxx represents any kind of Python object, and craft a __del__ method so that the same function is recursively called with the same object. I recently submitted corrections for 3 problems found this way. Here are two more examples of this method: #==================================== class Special: def __del__(self): print a.args class MyException(BaseException): def __init__(self): global a a = self BaseException.__init__(self, Special(), 0) BaseException.__init__(self, "other", 1) MyException() # segfault #==================================== import sys class Special2(str): def __del__(self): f.__init__("@temp", "w") f = file(Special2("@temp"), "w") f.__init__("@temp", "w") # segfault #==================================== Issue1020188 (which is still open btw) deals with member reset to NULL; but any modification of the pointer is potentially concerned. And the correction is always the same: use Py_CLEAR, or a similar construction that detach the value from the structure before defcref'ing it. I think it would help a lot of code if we had a safe standard way to set struct members from C. A macro like the following: Py_SETREF(lvalue, newobj) (whatever its name) would perform the assignment and expand to code equivalent to: PyObject* oldobj = lvalue; Py_INCREF(newobj); lvalue = newobj; Py_DECREF(oldobj); I am currently searching for all places that could benefit of this, but I am not sure to find a test case for every potential crash. Most of the time, it is very unlikely that "normal" python code can fall in these traps (who calls f.__init__ in a __del__ method?), with the exception of the one corrected by r60871. Should we however intensively search and correct all of them? Is there a clever way to prevent these problems globally, for example by delaying finalizers "just a little"? -- Amaury Forgeot d'Arc

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Py_CLEAR to avoid crashes
by Jim Jewett 18 Feb '08

18 Feb '08

> A simple way to do this would be to push objects whose > refcounts had reached 0 onto a list instead of finalizing them > immediately, and have PyEval_EvalFrameEx periodically swap > in a new to-delete list and delete the objects on the old one. Some of the memory management threads discussed something similar to this, and pointed to IBM papers on Java. By adding states like "tenatively finalizable", the cost of using multiple processors was reduced. The down side is that objects which could be released (and recycled) immediately won't be -- which slows down a fair number of real-world programs that are used to the CPython refcount model. If the resource not being immediately released is scarce (such as file handles), it gets even worse. -jJ

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dir() and __all__
by Raymond Hettinger 16 Feb '08

16 Feb '08

Should dir(module) use __all__ when defined? >>> dir(Queue) ['Empty', 'Full', 'LifoQueue', 'PriorityQueue', 'Queue', '__all__', '__builtins__', '__doc__', '__file__', '__name__', '__package__', '_time', 'deque', 'heapq'] >>> Queue.__all__ ['Empty', 'Full', 'Queue', 'PriorityQueue', 'LifoQueue'] I like the second one better. Raymond

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Calling a builtin from C code; PEP 3101 format() builtin
by Eric Smith 16 Feb '08

16 Feb '08

While implementing "".format(), I need to call the builtin format() function, which I've already implemented (in bltinmodule.c:builtin_format()). In the py3k branch, I just hardcoded the same functionality into "".format(), which seems like the wrong thing to do, given how complex the code is. I see 2 approaches: 1: exposing builtin_format(), probably giving it another name (PyObject_Format?) and moving it somewhere other than bltinmodule.c. 2: Instead of calling the C code directly, lookup "format" in Python's builtins, and call it. This, I think, would allow you to override the global format() function if you wanted to modify the behavior (although I can't think of any use case for wanting to do that). I don't see where either behavior is specified in the PEP. If option 2 is preferred, could someone give me a pointer to how to find a builtin function from C code? Thanks.

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Summary of Tracker Issues
by Tracker 15 Feb '08

15 Feb '08

ACTIVITY SUMMARY (02/08/08 - 02/15/08) 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. 1720 open (+39) / 12232 closed (+13) / 13952 total (+52) Open issues with patches: 449 Average duration of open issues: 745 days. Median duration of open issues: 1081 days. Open Issues Breakdown open 1695 (+37) pending 25 ( +2) Issues Created Or Reopened (53) _______________________________ PYO file permission problem 02/08/08 http://bugs.python.org/issue2051 created stocker81 Lack of difflib.HtmlDiff unicode support 02/08/08 http://bugs.python.org/issue2052 created josephoenix IDLE - standardize dialogs 02/09/08 http://bugs.python.org/issue2053 created taleinat patch add ftp-tls support to ftplib - RFC 4217 02/09/08 http://bugs.python.org/issue2054 created gregory.p.smith easy test_fcntl.py converted to unittest 02/09/08 http://bugs.python.org/issue2055 created giampaolo.rodola patch install command rejects --compiler option 02/10/08 CLOSED http://bugs.python.org/issue2056 created kermode difflib: add patch capability 02/10/08 http://bugs.python.org/issue2057 created techtonik reduce tarfile memory footprint 02/10/08 http://bugs.python.org/issue2058 created lars.gustaebel patch OptionMenu class is defined both in Tkinter and Tix 02/10/08 http://bugs.python.org/issue2059 created isandler python2.6 -3 gives "warning: callable() not supported in 3.x" on 02/10/08 http://bugs.python.org/issue2060 created eopadoan IDLE - autocompletion to support alternate patch separators 02/10/08 http://bugs.python.org/issue2061 created taleinat patch IDLE - autocompletion logic optimization 02/10/08 http://bugs.python.org/issue2062 created taleinat patch os.times() utime and stime exchanged on windows 02/11/08 CLOSED http://bugs.python.org/issue2063 created kcwu patch List of Dicts problem 02/11/08 CLOSED http://bugs.python.org/issue2064 created sunaluak trunk version does not compile with vs8 and vc6 02/11/08 http://bugs.python.org/issue2065 created amaury.forgeotdarc Adding new CNS11643, a *huge* charset, support in cjkcodecs 02/11/08 http://bugs.python.org/issue2066 created hyeshik.chang file.__exit__ does not call subclass' close method 02/11/08 http://bugs.python.org/issue2067 created belopolsky SimpleXMLRPCServer documentation about rpc_paths might be wrong 02/11/08 http://bugs.python.org/issue2072 created schwarz asynchat push always sends 512 bytes (ignoring ac_out_buffer_siz 02/11/08 http://bugs.python.org/issue2073 created mkc pprint._safe_repr() unsafe on ordering differently types objects 02/12/08 http://bugs.python.org/issue2074 created percivall Float number comparision problem 02/12/08 CLOSED http://bugs.python.org/issue2075 created tsxy xmlrpclib closes connection after each call 02/12/08 http://bugs.python.org/issue2076 created erno Interpreter crash on shutdown 02/12/08 http://bugs.python.org/issue2077 created rupert.summerton CSV Sniffer does not function properly on single column .csv fil 02/12/08 http://bugs.python.org/issue2078 created jplaverdure UserDict documentation typo 02/12/08 http://bugs.python.org/issue2079 created gsf Syntax for property set method 02/12/08 CLOSED http://bugs.python.org/issue2085 created LambertDW __import__ with fromlist=[''] causes double initialization of mo 02/12/08 http://bugs.python.org/issue2090 created hauser file accepts 'rU+' as a mode 02/12/08 http://bugs.python.org/issue2091 created brett.cannon PEP-3100 should reflect removal of 'cmp' parameter in sort() and 02/13/08 CLOSED http://bugs.python.org/issue2092 created kbk Reporting bugs page refers to old site 02/13/08 CLOSED http://bugs.python.org/issue2096 created Yinon typo in exception-handling tutorial 02/13/08 CLOSED http://bugs.python.org/issue2097 created Yinon unclear error message on bug reporting 02/13/08 CLOSED http://bugs.python.org/issue2099 created Yinon unit test UnicodeWarning 02/13/08 http://bugs.python.org/issue2100 created JosephArmbruster xml.dom documentation doesn't match implementation 02/13/08 http://bugs.python.org/issue2101 created stefan New style vs. old style classes __ror__() operator overloading 02/13/08 http://bugs.python.org/issue2102 created calvin __x should be _x in documentation of property() 02/13/08 CLOSED http://bugs.python.org/issue2103 created bgailer ? 02/14/08 CLOSED http://bugs.python.org/issue2109 created susanna Implement __format__ for Decimal 02/14/08 http://bugs.python.org/issue2110 created facundobatista mmap segfaults when trying to write a block opened with PROT_REA 02/14/08 http://bugs.python.org/issue2111 created therve mmap.error should be a subclass of EnvironmentError and not a di 02/14/08 http://bugs.python.org/issue2112 created therve patch, easy Bad interaction between signal and subprocess 02/14/08 http://bugs.python.org/issue2113 created piro test_decimal failure on OSX 10.3 02/14/08 CLOSED http://bugs.python.org/issue2114 created ronaldoussoren __slots__ make attribute setting 10x slower 02/14/08 http://bugs.python.org/issue2115 created jyasskin weakref copy module interaction 02/14/08 http://bugs.python.org/issue2116 created rharris smtplib.SMTP() raises socket.error rather than SMTPConnectError 02/14/08 http://bugs.python.org/issue2118 created stranger4good Empty test 02/14/08 CLOSED http://bugs.python.org/issue2119 created loewis broken links in advocacy HOWTO 02/15/08 http://bugs.python.org/issue2120 created salty-horse complex constructor doesn't accept string with nan and inf 02/15/08 http://bugs.python.org/issue2121 created tiran mmap.flush does not check for errors on windows 02/15/08 http://bugs.python.org/issue2122 created schmir ctypes pointer not always keeping target alive 02/15/08 http://bugs.python.org/issue2123 created arigo xml.sax and xml.dom fetch DTDs by default 02/15/08 http://bugs.python.org/issue2124 created akuchling [patch] Read support for Records in msilib 02/15/08 http://bugs.python.org/issue2125 created flub test_sqlite fails on OSX G5 arch if test_ctypes is run 02/10/08 http://bugs.python.org/issue1581906 reopened skip.montanaro Issues Now Closed (29) ______________________ Probable extra semicolon in Py_LeaveRecursiveCall macro 63 days http://bugs.python.org/issue1595 loewis IDLE messes around with sys.exitfunc 58 days http://bugs.python.org/issue1647 kbk Force WINVER 0x0500 (Windows 2000) 43 days http://bugs.python.org/issue1706 tiran Three bugs of FCICreate (PC/_msi.c) 39 days http://bugs.python.org/issue1736 loewis patch IDLE fails to launch 39 days http://bugs.python.org/issue1743 kbk infinite loop in httplib 14 days http://bugs.python.org/issue1966 loewis patch, easy asyncore loop lacks timers and work tasks 10 days http://bugs.python.org/issue2006 facundobatista Turn NamedTemporaryFile into a context manager 5 days http://bugs.python.org/issue2021 ncoghlan patch Class instance attributes that are property() should appear in _ 1 days http://bugs.python.org/issue2040 tiran IDLE - Restart Shell & Run Module 3 days http://bugs.python.org/issue2049 taleinat patch install command rejects --compiler option 0 days http://bugs.python.org/issue2056 loewis os.times() utime and stime exchanged on windows 2 days http://bugs.python.org/issue2063 georg.brandl patch List of Dicts problem 0 days http://bugs.python.org/issue2064 tiran Float number comparision problem 0 days http://bugs.python.org/issue2075 amaury.forgeotdarc Syntax for property set method 0 days http://bugs.python.org/issue2085 georg.brandl PEP-3100 should reflect removal of 'cmp' parameter in sort() and 1 days http://bugs.python.org/issue2092 kbk Reporting bugs page refers to old site 0 days http://bugs.python.org/issue2096 facundobatista typo in exception-handling tutorial 0 days http://bugs.python.org/issue2097 facundobatista unclear error message on bug reporting 0 days http://bugs.python.org/issue2099 facundobatista __x should be _x in documentation of property() 0 days http://bugs.python.org/issue2103 marketdickinson ? 0 days http://bugs.python.org/issue2109 amaury.forgeotdarc test_decimal failure on OSX 10.3 1 days http://bugs.python.org/issue2114 ronaldoussoren Empty test 0 days http://bugs.python.org/issue2119 loewis virtual IO for embedding Py in server 2358 days http://bugs.python.org/issue456086 draghuram Uninstall target in makefile 2112 days http://bugs.python.org/issue549764 draghuram Embedded python thread crashes 1018 days http://bugs.python.org/issue1193099 amaury.forgeotdarc Spurious Tabnanny error 511 days http://bugs.python.org/issue1562716 kbk simple moves freeze IDLE 497 days http://bugs.python.org/issue1571112 kbk 0.0 and -0.0 identified, with surprising results 339 days http://bugs.python.org/issue1678380 marketdickinson patch Top Issues Most Discussed (10) ______________________________ 25 Move Demo/classes/Rat.py to Lib/fractions.py and fix it up. 56 days open http://bugs.python.org/issue1682 11 Adding new CNS11643, a *huge* charset, support in cjkcodecs 4 days open http://bugs.python.org/issue2066 9 Force WINVER 0x0500 (Windows 2000) 43 days closed http://bugs.python.org/issue1706 8 trunk version does not compile with vs8 and vc6 4 days open http://bugs.python.org/issue2065 7 __slots__ make attribute setting 10x slower 1 days open http://bugs.python.org/issue2115 6 test_decimal failure on OSX 10.3 1 days closed http://bugs.python.org/issue2114 6 IDLE - autocompletion logic optimization 5 days open http://bugs.python.org/issue2062 6 shutil.destinsrc returns wrong result when source path matches 7 days open http://bugs.python.org/issue2047 5 Inheriting from ABCs makes classes slower. 38 days open http://bugs.python.org/issue1762 4 __x should be _x in documentation of property() 0 days closed http://bugs.python.org/issue2103

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Adding __format__ to classic classes
by Eric Smith 14 Feb '08

14 Feb '08

When backporting PEP 3101, do we want to add __format__ to classic classes? If so, could someone give me a pointer on how to implement this? I don't see where to hook it up. Thanks. Eric.

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RELEASED Python 2.5.2, release candidate 1
by "Martin v. Löwis" 14 Feb '08

14 Feb '08

On behalf of the Python development team and the Python community, I'm happy to announce the release of Python 2.5.2 (release candidate 1). This is the second bugfix release of Python 2.5. Python 2.5 is now in bugfix-only mode; no new features are being added. According to the release notes, over 100 bugs and patches have been addressed since Python 2.5.1, many of them improving the stability of the interpreter, and improving its portability. For more information on Python 2.5.2, including download links for various platforms, release notes, and known issues, please see: http://www.python.org/2.5.2/ Highlights of this new release include: Bug fixes. According to the release notes, at least 100 have been fixed. Highlights of the previous major Python release (2.5) are available from the Python 2.5 page, at http://www.python.org/2.5/highlights.html Enjoy this release, Martin Martin v. Loewis martin(a)v.loewis.de Python Release Manager (on behalf of the entire python-dev team)

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2.5.2 freeze upcoming
by "Martin v. Löwis" 14 Feb '08

14 Feb '08

The 2.5 maintenance branch will be frozen tomorrow (Thursday) around 7:00 UTC. Please don't make any changes to the branch after that point unless you are directly involved in the release process. If there are any issues that you think should be considered before the 2.5.2 release, please assign them to me with high priority. Regards, Martin

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test_decimal failure on OSX 10.3
by Ronald Oussoren 14 Feb '08

14 Feb '08

Hi, I've just filed issue2114 (http://bugs.python.org/issue2114) because test_decimal.py fails on OSX 10.3 with Python 2.5.2c1 (using the python.org build that will be released soon). The same test passes on OSX 10.4 and 10.5 (both Intel and PPC) using the exact same binaries. IIRC the 2.5.1 release had no unexpected test failures on OSX 10.3, so this is a regression in that regard. Ronald

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