Mailman 3 July 2007 - Python-Dev

Re: [Python-Dev] proposed attribute lookup optimization
by Paul Pogonyshev July 11, 2007

July 11, 2007

[I don't know why I didn't receive this mail, presumably spam filter at gmx.net sucks as always] Phillip J. Eby wrote: > At 08:23 PM 7/8/2007 +0300, Paul Pogonyshev wrote: > >I would like to propose an optimization (I think so, anyway) for the > >way attributes are looked up. [...] > > [...] > > Again, though, this has already been proposed, and I believe there's > a patch awaiting review for inclusion in 2.6 (and presumably 3.0). OK, good to know. Of course it is better if done by someone familiar with Python internals :) After proposing this I decided it wasn't worthwile, since it would require cache revalidation after any assignment to a new class attribute. But supposedly I just have incorrect picture of what is often in Python :) Paul

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itertools addition: getitem()
by Walter Dörwald July 11, 2007

July 11, 2007

I'd like to propose the following addition to itertools: A function itertools.getitem() which is basically equivalent to the following python code: _default = object() def getitem(iterable, index, default=_default): try: return list(iterable)[index] except IndexError: if default is _default: raise return default but without materializing the complete list. Negative indexes are supported too (this requires additional temporary storage for abs(index) objects). The patch is available at http://bugs.python.org/1749857 Servus, Walter

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Add a -z interpreter flag to execute a zip file
by Andy C July 11, 2007

July 11, 2007

I'd like to request comments on this patch I submitted: https://sourceforge.net/tracker/index.php?func=detail&aid=1739468&group_id=… There are many details given in the comments on that page. This can be used to deploy Python programs in a very lightweight and cross-platform way. You could imagine a cgi script or a light web app server being deployed like this. I have personally deployed Python programs using zip files and this would get rid of the need for boilerplate needed for each platform. The good thing about this is that it's extremely simple -- basically 20 lines of C code to add a -z flag that calls a 3-line Python function in the runpy module. I don't believe it overlaps with anything that already exists. py2exe and py2app are platform specific and bundle the Python interpreter. This will be a cross platform binary that doesn't bundle the Python interpreter. It doesn't require eggs but I think it would work fine with eggs, and could help fix a little bug as I mentioned on the patch page. Nick Coghlan has reviewed the patch and seems to think it's a good idea. Thomas Wouters also said he likes it, and I ran it by Guido earlier and he seemed to think the idea is good, although I don't think he has seen the implementation. thanks, Andy

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Should r53624 be applied to release branches?
by Aaron Bingham July 10, 2007

July 10, 2007

Hello, We recently had a production failure caused by the issue fixed in r53624 on the trunk [1]. I see that this patch has also been applied to py3k-struni. Should this patch be merged to the release branches? In the meantime we will have to patch subprocess.py ourselves. [1] http://mail.python.org/pipermail/python-checkins/2007-February/058421.html Thanks, -- Aaron Bingham Senior Software Engineer bingham(a)cenix-bioscience.com Tel. +49 (0)351 4173-146 Fax +49 (0)351 4173-109 Cenix BioScience GmbH Tatzberg 47 01307 Dresden, Germany www.cenix-bioscience.com --------------------------------------------------------- Sitz der Gesellschaft (Place of Business): Dresden Geschäftsführer (CEO): Dr. Christophe J. Echeverri Amtsgericht (Local Court): Dresden, HRB 19964 Ust-ID (VAT-No.): DE205824437 --------------------------------------------------------- WICHTIGE INFORMATION: Diese Email, inklusive der Anhänge, ist ausschließlich für den Gebrauch durch die hierzu berechtigten Empfänger bestimmt. Sollten Sie nicht der für diese Email bestimmte Adressat sein, ist Ihnen jede Veröffentlichung, Vervielfältigung oder Weitergabe dieses Dokuments untersagt. Bitte senden Sie eine Email an info(a)cenix-bioscience.com, falls Sie diese Email versehentlich erhalten haben. Vielen Dank! IMPORTANT NOTICE: This message, including any attached documents, is intended only for the use of the individual or entity to which it is addressed, and may contain information that is privileged, confidential and exempt from disclosure under applicable law. If the reader of this Message is not the intended recipient, or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify Cenix BioScience immediately by email at info(a)cenix-bioscience.com. Thank you.

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Weekly Python Patch/Bug Summary
by Kurt B. Kaiser July 10, 2007

July 10, 2007

Patch / Bug Summary ___________________ Patches : 392 open ( +7) / 3792 closed ( +2) / 4184 total ( +9) Bugs : 1042 open (+13) / 6757 closed (+13) / 7799 total (+26) RFE : 263 open ( +1) / 292 closed ( +1) / 555 total ( +2) New / Reopened Patches ______________________ "%d" format handling for long values (2007-06-25) http://python.org/sf/1742669 opened by Gabriel Genellina Read Write lock (2007-06-27) http://python.org/sf/1744382 opened by Yaakov Nemoy Improve exception pickling support (2007-06-27) http://python.org/sf/1744398 opened by Eric Huss Patch for feat. 713877 Expose callbackAPI in readline module (2007-06-27) http://python.org/sf/1744456 opened by strank IPv6 Interface naming/indexing functions (2007-07-02) http://python.org/sf/1746656 opened by Michael Meier Limiting data copy in xmlrpclib (2007-07-04) http://python.org/sf/1747670 opened by Gael Le Mignot Extra optional argument to os.path.expandvars (2007-07-06) http://python.org/sf/1748960 opened by Geoffrey Bache New byte packing format for the struct module (2007-07-07) http://python.org/sf/1749662 opened by Robert Zeh itertools.getitem() (2007-07-08) http://python.org/sf/1749857 opened by Walter Dörwald Patches Closed ______________ Fix for duplicate "preferences" menu-OS X (2007-04-03) http://python.org/sf/1693258 closed by ronaldoussoren Mac OS X: libtool (2007-03-03) http://python.org/sf/1673122 closed by ronaldoussoren New / Reopened Bugs ___________________ Incorrect docs for optparse OptionParser add_help_option (2007-06-23) http://python.org/sf/1742164 opened by Forest Wilkinson ZipFile.writestr writes incorrect extended local headers (2007-06-23) http://python.org/sf/1742205 opened by alexis Documentation for BaseHTTPServer.HTTPServer (2007-06-25) http://python.org/sf/1742837 opened by Brandon Mintern Pickling of exceptions broken (2007-06-25) http://python.org/sf/1742889 opened by Jim Fulton shlex handles 'None' poorly (2007-06-25) CLOSED http://python.org/sf/1742901 opened by Seth Vidal can't run single lamba funcs as unittest (2007-06-25) http://python.org/sf/1742940 opened by timmeh conditional expressions vs. () and * in call arguments. (2007-06-26) CLOSED http://python.org/sf/1743665 opened by Mike Meyer Some incorrect national characters (Polish) in unicodedata (2007-06-26) CLOSED http://python.org/sf/1743795 opened by admindomeny Examples dropped from PDF version of docs (2007-06-26) http://python.org/sf/1743846 opened by Terry Carroll cvs.get_dialect() return a class object (2007-06-28) http://python.org/sf/1744580 opened by Christian Kristukat Newline skipped in "for line in file" (2007-06-28) http://python.org/sf/1744752 opened by Rune Devik DoS smtpd vulnerability (2007-06-28) http://python.org/sf/1745035 opened by billiejoex 2.5.1 curses panel segfault in new_panel on aix 5.3 (2007-06-29) http://python.org/sf/1745108 opened by Mattias Wadenstein pdtri gives wrong results (2007-06-29) CLOSED http://python.org/sf/1745178 opened by Nikke Knatterton Filename providing cross platform capability (2007-06-29) CLOSED http://python.org/sf/1745533 reopened by loewis Filename providing cross platform capability (2007-06-29) CLOSED http://python.org/sf/1745533 opened by Damian Bad attributes/data handling in SGMLib (2007-06-30) http://python.org/sf/1745761 opened by Alvaro Lopez class mutex doesn't do anything atomically (2007-07-01) http://python.org/sf/1746071 opened by David Benbennick long.__str__ is quadratic time (2007-07-01) http://python.org/sf/1746088 opened by David Benbennick AMD64 installer does not place python25.dll in system dir (2007-07-02) http://python.org/sf/1746880 opened by Roger Upole chown broken on 64bit (2007-07-04) http://python.org/sf/1747858 opened by Neal D. Becker Module-level stack scopes have incorrect bindings. (2007-07-04) http://python.org/sf/1748015 opened by Nefarious CodeMonkey, Jr. inspect.getargspec fails on built-in or slot wrapper methods (2007-07-04) http://python.org/sf/1748064 opened by Michael A. Hawker str.join() intercepts UnicodeDecodeError raised by iterator (2007-07-05) CLOSED http://python.org/sf/1748292 opened by Christoph Zwerschke imaplib cannot handle mailboxes with ACL: lrs (2007-07-07) http://python.org/sf/1749512 opened by Florian Friesdorf PLATFORM macro in PC/pyconfig.h already defined by Apache (2007-07-07) http://python.org/sf/1749567 opened by Adal Chiriliuc expanduser("~") on Windows looks for HOME first (2007-07-07) http://python.org/sf/1749583 opened by Edward Diener os.getlogin should use the DISPLAY and not the tty (2007-07-08) http://python.org/sf/1750013 opened by Serge Noiraud Python 2.5+ skips while statements in debuggers (2007-07-08) http://python.org/sf/1750076 opened by Chris Lasher Bugs Closed ___________ Odd UDP problems in socket library (2007-06-22) http://python.org/sf/1741898 deleted by bluej774 shlex handles 'None' poorly (2007-06-25) http://python.org/sf/1742901 closed by gbrandl python: Modules/gcmodule.c:240: update_refs: Assertion `gc-> (2007-06-20) http://python.org/sf/1740599 closed by stuffduff shutil.move doesn't work when only case changes (2007-06-16) http://python.org/sf/1738441 closed by ggambett conditional expressions vs. () and * in call arguments. (2007-06-26) http://python.org/sf/1743665 closed by gbrandl Some incorrect national characters (Polish) in unicodedata (2007-06-26) http://python.org/sf/1743795 closed by loewis pdtri gives wrong results (2007-06-29) http://python.org/sf/1745178 closed by gbrandl Filename providing cross platform capability (2007-06-29) http://python.org/sf/1745533 closed by loewis Filename providing cross platform capability (2007-06-29) http://python.org/sf/1745533 closed by atagar str.join() intercepts UnicodeDecodeError raised by iterator (2007-07-05) http://python.org/sf/1748292 closed by lemburg Tkinter is not working on trunk (2.6) (2007-06-09) http://python.org/sf/1733943 closed by kbk logging module formatter problem with %(filename)s (2006-06-19) http://python.org/sf/1508369 closed by ronaldoussoren Mac Universal Build of Python confuses distutils (2006-07-28) http://python.org/sf/1530142 closed by ronaldoussoren Mac build fails if not building universal due to libtool (2007-06-12) http://python.org/sf/1736103 closed by jackjansen Status bar on OSX garbled (2007-01-04) http://python.org/sf/1627543 closed by ronaldoussoren New / Reopened RFE __________________ please add wsgi to SimpleXMLRPCServer (2007-06-30) http://python.org/sf/1745722 opened by Helmut Grohne RFE Closed __________ MacPython ignores user-installed Tcl/Tk (2006-09-21) http://python.org/sf/1563046 closed by ronaldoussoren

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Summary of Tracker Issues
by Tracker July 9, 2007

July 9, 2007

ACTIVITY SUMMARY (07/01/07 - 07/08/07) 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. 1645 open ( +0) / 8584 closed ( +0) / 10229 total ( +0) Average duration of open issues: 850 days. Median duration of open issues: 798 days. Open Issues Breakdown open 1645 ( +0) pending 0 ( +0)

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proposed attribute lookup optimization
by Paul Pogonyshev July 8, 2007

July 8, 2007

Hi, I would like to propose an optimization (I think so, anyway) for the way attributes are looked up. Currently, it is done like this: return value of attribute in instance.__dict__ if present for type in instance.__class__.__mro__: return value of attribute in type.__dict__ if present raise AttributeError I propose adding to each type a C-implementation-private dictionary of attribute-name => type-in-which-defined. Then, it will not be necessary to traverse __mro__ on each attribute lookup for names which are present in this lookup dictionary. This optimization will not have any effect for attributes defined on instance. It will, however, for type attributes, most notably for methods. It will most likely cause a slowdown for looking up attributes that are defined directly on self.__class__, not on any of its bases. However, I believe it will be a benefit for all non-extremely shallow inheritance tree. Especially if they involve multiple inheritance. One open question is what to do in case an attribute on a type is set or deleted. Python example: class Current (type): @staticmethod def getattribute (self, name): dict = object.__getattribute__(self, '__dict__') if name in dict: return dict[name] mro = object.__getattribute__ (self, '__class__').__mro__ for type in mro: dict = type.__dict__ if name in dict: return dict[name] raise AttributeError def __init__(self, name, bases, dict): super (Current, self).__init__(name, bases, dict) self.__getattribute__ = Current.getattribute class Optimized (type): @staticmethod def getattribute (self, name): dict = object.__getattribute__(self, '__dict__') if name in dict: return dict[name] # <possible optimization> lookup = object.__getattribute__ (self, '__class__').__lookup_cache__ if name in lookup: return lookup[name].__dict__[name] # </possible optimization> mro = object.__getattribute__ (self, '__class__').__mro__ for type in mro: dict = object.__getattribute__(type, '__dict__') if name in dict: return dict[name] raise AttributeError # <possible optimization> def build_lookup_cache (self): lookup = {} for type in self.__mro__: for name in type.__dict__: if name not in lookup: lookup[name] = type return lookup # </possible optimization> def __init__(self, name, bases, dict): super (Optimized, self).__init__(name, bases, dict) # <possible optimization> self.__lookup_cache__ = self.build_lookup_cache () # </possible optimization> self.__getattribute__ = Optimized.getattribute class A (object): __metaclass__ = Optimized x = 1 class B (A): pass class C (B): pass class D (C): pass class E (D): pass t = E () for k in xrange (100000): t.x Try swapping metaclass of A from Optimized to Current and measure execution time. Paul

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Python for embedding?
by "Knut A. Wikström" July 8, 2007

July 8, 2007

Python is a great language. We all know. But I have tried implementing Python into C/C++ applications, and have a) had a lot of trouble getting it running properly and b) it is slow, compared to other languages, like LUA. What is my idea, is to make a Python implementation made to be embedded into applications.. It will have these features: a) Small footprint. b) Easy-to-use, but still advanced API. c) Stackless. d) A smaller standard library. e) Fast. The smaller footprint is, so that it will use minimal resources possible, leaving more for the underlying application. The API is the most important thing, really, as this distro will be made for embedding. It will not have any compiler features, just an interpreter. Stackless Python is - as we know - faster than Python. Another good reason to use it in embedding. A lot of the standard library is seldom used; we only need the core functions. Fast, of course! It needs to be the fastest interpreter ever written (at least fast). Hope you have any ideas/comments! ~Knut

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Python 2.6 BaseException.message deprecation, really needed?
by Gustavo Carneiro July 8, 2007

July 8, 2007

In PyGObject we want to use a 'message' attribute in an exception defined by us. The name 'message' comes from a C API, therefore we would like to keep it for easier mapping between C and Python APIs. Why does Python have to deprecate this attribute? .../gobject/option.py:187: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6 gerror.message = str(error) -- Gustavo J. A. M. Carneiro INESC Porto, Telecommunications and Multimedia Unit "The universe is always one step beyond logic." -- Frank Herbert

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Adding NetworkIOError for bug 1706815
by Gregory P. Smith July 6, 2007

July 6, 2007

In response to bug 1706815 and seeing messy code to catch errors in network apps I've implemented most of the ideas in the bug and added a NetworkIOError exception (child of IOError). With this, socket.error would now inherit from NetworkIOError instead of being its own thing (the old one didn't even declare a parent!). Complete patch attached to the bug. All unit tests pass. Documentation updates included. http://sourceforge.net/tracker/index.php?func=detail&aid=1706816&group_id=5… Any thoughts? I'm happy with it and would like to commit it if folks agree.

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