Mailman 3 March 2002 - Python-Dev

Re: [Python-Dev] Activating pymalloc
by Michael Hudson March 25, 2002

March 25, 2002

Tim Peters <tim.one(a)comcast.net> writes: > [Neal] > > A lot of extensions will break. The example code in xxmodule.c was > > "wrong" for years. > > Ditto Zope (as Guido said), ditto Marc-Andre's extensions, ditto > NumPy (IIRC), yadda yadda yadda. I don't know whether MarkH has > tried the massive Win32 extensions with pymalloc yet. I think one of the reasons lots of modules break is that back in the 1.5.2 days, PyObject_Del didn't exist, and you were expected to use PyMem_Del. This now breaks. Could be misremembering. Cheers, M. -- The gripping hand is really that there are morons everywhere, it's just that the Americon morons are funnier than average. -- Pim van Riezen, alt.sysadmin.recovery

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2.2.1c1 platform reports.
by Michael Hudson March 25, 2002

March 25, 2002

I crunched through the various platform experiences I'd heard for 2.2.1c1, and came up with the following. Can anyone fill in some gaps, add comments or dig into some of the mentioned problems? Things are looking fairly good, but reports from AIX-land in particular are making my head spin like a top. If I remember, I'll try to keep a copy of this at http://starship.python.net/crew/mwh/221c1-reports.txt Hardware: Intel OS: Linux, BeOS, Win32 all fine. OS: FreeBSD test_math.test_exceptions blows up with "sqrt(-1) does not raise ValueError". It seems FreeBSD's libm doesn't set errno in this case, and that MacOSX has inherited this behaviour (see below) OS: OpenBSD test_signal hangs on the sf compile farm. We've had reports of this before. I can't be bothered to dig into it today. OS: NetBSD no reports. Hardware: Sparc OS: Solaris, Linux also fine Hardware: RS/6000 OS: AIX 3.5.2 ./configure dies without "--without-gcc"; don't know if it actually builds with it... OS: AIX 4.2 some posixmodule gremlins. Suggested fix to reporter; awaiting confirmation before I check it in. OS: Linux OK on the compile farm. Hardware: Mac OS: MacOS 8.1 Doesn't work at all apparently :( A linking problem. I hope Jack can sort this out -- certainly noone else can. Oh, apparently it's fixed, but it doesn't work on 8.5, or something... OS: MacOS 9 I doubt Jack would have let me release c1 if this hadn't worked :) OS: MacOSX Has the same test_math problem as FreeBSD/x86 (which is perhaps not so surprising). Everything else is fine, except on sf's compile farm machine, which seems to be fubarred anyway. OS: Linux Fine. Hardware: S390 OS: Linux Fine. Hardware: Alpha OS: Linux Fine (I think) OS: Digital Unix^W^WTru64^WWhatever V4.0 Threads b0rken, test_format fails (old libc bug) OS: Digital Unix^W^WTru64^WWhatever V5.1 Fine. OS: NetBSD (from Compaq's testdrive program). Not happy. Anyone care to dig in? Hardware: IA-64 OS: Linux Fine. Hardware: HP PA-RISC (shut up at the back there!) OS: HP-UX A.09.05 Apparently OK (!). It built, anyway. OS: HP-UX B.11.00 Seems to have unicode difficulties. Hardware: SGI OS: Irix 6.5 Fine. Hardware: Cray (!) J90 OS: UNICOS 10.0.0.3 Got nowhere, as it couldn't define PY_UNICODE_TYPE. Asked tester to try --disable-unicode and it dies in _sre.c: cc -DNDEBUG -O -I. -I./Include -DHAVE_CONFIG_H -c ./Modules/_sre.c -o Modules/_sre.o CC-147 cc: ERROR File = ./Modules/_sre.c, Line = 1791 Declaration is incompatible with "int join(char *, char *)" (declared at line 300 of "/usr/include/unistd.h"). join(PyObject* list, PyObject* pattern) Sigh... -- ZAPHOD: Listen three eyes, don't try to outwierd me, I get stranger things than you free with my breakfast cereal. -- The Hitch-Hikers Guide to the Galaxy, Episode 7

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[development doc updates]
by Fred L. Drake March 24, 2002

March 24, 2002

The development version of the documentation has been updated: http://python.sourceforge.net/csstest-docs/ This is the experimental formatting for the documentation. This version should work better for Opera users; it should work fine for Opera 6, and works (slightly) better than it did for Opera 5. There's probably no change for other browsers.

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Info needed on metaclasses / type-ing
by Dimitris Garanatsios March 24, 2002

March 24, 2002

I recently browsed through an unfinished book of Bruce Eckel, "Thinking in Python", Revision 0.1.2 I can't remember the URL where i got it, but i found it through searching for documentation on Python from the main site, www.python.org I found the following peace of code there: ------------------------------------------------------------------ #: c01:SingletonMetaClass.py class SingletonMetaClass(type): def __init__(cls, name, bases, dict): super(SingletonMetaClass, cls).__init__(name, bases, dict) original_new = cls.__new__ def my_new(cls, *args, **kwds): if cls.instance == None: cls.instance = original_new(cls, *args, **kwds) return cls.instance cls.instance = None cls.__new__ = staticmethod(my_new) class bar(object): __metaclass__ = SingletonMetaClass def __init__(self,val): self.val = val def __str__(self): return `self` + self.val ... #:~ ------------------------------------------------------------------ My question is about the "SingletonMetaClass" class. I have tried in the past to create my own types using Python and just could not find a way of doing that since built-in type objects' structure where not documented. The "SingletonMetaClass though", as far as i can understand, please help me with that, is doing exactly what i wanted: a new type definition. I browsed Python's manuals to find more about the attributes and functions that are used, but found nothing... Could anyone help me find information about the meaning and use of the following attributes/functions/objects? These are: --- the "__metaclass__" attribute of the "bar" class (derived from object) --- the "object" object itself --- the "super" function used in the "SingletonMetaClass" class (a class for a new type object?) --- the "__new__" attribute/method of a class (applies to any class?) --- the "staticmethod" function used in the "SingletonMetaClass" class --- any additional info about related classes or functions that are not used in the above example but exist and are available to use Thanx, Dimitris

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Weekly Python Bug/Patch Summary
by Skip Montanaro March 24, 2002

March 24, 2002

Bug/Patch Summary ----------------- 254 open / 2338 total bugs 95 open / 1386 total patches Closed Bugs ----------- Distutils should have a Setup parser (2001-03-23) http://python.org/sf/410878 linuxaudiodev fails during "make test". (2001-03-24) http://python.org/sf/410993 xmlrpclib won't marshal new types (2001-10-10) http://python.org/sf/469972 Deprecate modules (2001-10-24) http://python.org/sf/474585 python version benchmark (2001-10-25) http://python.org/sf/474992 Uncaught MI order conflict (2001-11-14) http://python.org/sf/481985 dumbdbm fails to overwrite existing key (2001-11-16) http://python.org/sf/482460 Different behavior of readline() (2001-11-29) http://python.org/sf/487277 Int(long) causes Integer Overflow (2002-01-04) http://python.org/sf/499708 os.listdir("") bug on Windows (2002-01-07) http://python.org/sf/500705 type.__module__ problems (again?) (2002-01-15) http://python.org/sf/503837 Bad exceptions from pickle (2002-01-16) http://python.org/sf/504723 Super method search quirk (2002-01-17) http://python.org/sf/505028 python-mode.el sets TMPDIR to /usr/tmp (2002-01-18) http://python.org/sf/505488 Fix hardlink against NavServices (2002-01-18) http://python.org/sf/505587 urllib.urlopen results.readline is slow (2002-01-24) http://python.org/sf/508157 make test failure on sunos5 (2002-02-01) http://python.org/sf/512007 Very slow performance (2002-02-09) http://python.org/sf/515434 urlparse can get fragments wrong (2002-02-11) http://python.org/sf/516299 Error in tutorial chapter 4 (2002-02-15) http://python.org/sf/518076 undocumented argument in filecmp.cmpfile (2002-02-25) http://python.org/sf/522426 Segfault evaluating '%.100f' % 2.0**100 (2002-02-25) http://python.org/sf/522699 pickle/cPickle Inconsistent EOF handling (2002-02-26) http://python.org/sf/523020 Inaccuracy in PyErr_SetFromErrno()'s doc (2002-02-28) http://python.org/sf/523833 breaking file iter loop leaves file in stale state (2002-03-02) http://python.org/sf/524804 cmd.py does not flush stdout (2002-03-06) http://python.org/sf/526357 raw_input does not flush stdout (2002-03-06) http://python.org/sf/526382 tixwidgets.py improperly indented (2002-03-06) http://python.org/sf/526548 popen3 hangs on windows (2002-03-09) http://python.org/sf/527783 classmethod().__get__() segfault (2002-03-10) http://python.org/sf/528132 PyTraceBack_Store/Fetch are absent (2002-03-12) http://python.org/sf/528914 broken error handling in unicode-escape (2002-03-12) http://python.org/sf/529104 ICGlue byte alignment issue (2002-03-12) http://python.org/sf/529146 Linking under AIX failing (2002-03-13) http://python.org/sf/529713 pydoc regression (2002-03-14) http://python.org/sf/530070 Typo in 3.16 copy_reg doc (2002-03-14) http://python.org/sf/530143 redefining SRE_CODE in Modules/sre.h (2002-03-15) http://python.org/sf/530285 import and execfile don't handle utf-16 (2002-03-16) http://python.org/sf/530882 New Bugs -------- socket.sslerror is not a socket.error (2002-03-17) http://python.org/sf/531145 Bugs in rfc822.parseaddr() (2002-03-17) http://python.org/sf/531205 surprise overriding __radd__ in subclass of complex (2002-03-18) http://python.org/sf/531355 221 still doesn't work on OS 8.1 (2002-03-18) http://python.org/sf/531398 urllib ftp broken if Win32 proxy (2002-03-19) http://python.org/sf/532007 6.9 The raise statement is confusing (2002-03-20) http://python.org/sf/532467 Build python fails after fpectl (2002-03-20) http://python.org/sf/532618 Confusions in formatfloat (2002-03-20) http://python.org/sf/532631 Recursive class instance "error" (2002-03-20) http://python.org/sf/532646 isinstance() should respect __class__ (2002-03-20) http://python.org/sf/532767 NameError assigning to class in a func (2002-03-20) http://python.org/sf/532860 configure.in Assumes cc_r Exists on AIX. (2002-03-21) http://python.org/sf/533188 Complex power underflow raises exception (2002-03-21) http://python.org/sf/533198 __reduce__ does not work as documented (2002-03-21) http://python.org/sf/533291 not building on AIX (2002-03-21) http://python.org/sf/533306 rexec: potential security hole (2002-03-22) http://python.org/sf/533625 2.2 on HP-UX 11 64-bit - longs crash (2002-03-22) http://python.org/sf/533632 cut-o/paste-o in Marshalling doc: 2.2.1 (2002-03-22) http://python.org/sf/533735 AIX 3.2.5 Has No chroot/fsync Prototypes (2002-03-23) http://python.org/sf/534108 CODESET Doesn't Infer ERA et al. (2002-03-23) http://python.org/sf/534153 Running MacPython as non-priv user may fail (2002-03-23) http://python.org/sf/534158 Closed Patches -------------- Persistent connections in BaseHTTPServer (2001-06-06) http://python.org/sf/430706 ncurses form module (2001-09-04) http://python.org/sf/458534 allow dumbdbm to reuse space (2001-11-12) http://python.org/sf/480902 Final set of patches to Demo/tix (2001-11-27) http://python.org/sf/485959 Namespace selection for rlcompleter (2001-12-06) http://python.org/sf/490026 Lets Tkinter work with MacOSX native Tk (2001-12-06) http://python.org/sf/490100 make inspect.stack() work with PyShell (2001-12-07) http://python.org/sf/490374 Opt for tok_nextc (2001-12-12) http://python.org/sf/491936 Access to readline history elements (2001-12-16) http://python.org/sf/494066 test exceptions in various types/methods (2001-12-18) http://python.org/sf/494871 add an -q (quiet) option to pycompile (2001-12-20) http://python.org/sf/495598 Mach-O MacPython IDE! (2001-12-22) http://python.org/sf/496096 location of mbox (2001-12-27) http://python.org/sf/497097 robotparser.py fails on some URLs (2002-01-04) http://python.org/sf/499513 compileall.py -d errors (2002-01-10) http://python.org/sf/501713 call warnings.warn with Warning instance (2002-01-17) http://python.org/sf/504943 Script to move faqwiz entries. (2002-02-03) http://python.org/sf/512466 build, install in HP-UX10.20 (2002-02-05) http://python.org/sf/513329 Adding galeon support (2002-02-16) http://python.org/sf/518675 minor fix for regen on IRIX (2002-03-04) http://python.org/sf/525763 urllib2: duplicate call, stat attrs (2002-03-05) http://python.org/sf/525870 Enable pymalloc (2002-03-15) http://python.org/sf/530556 New Patches ----------- PEP 4 update: deprecations (2002-03-18) http://python.org/sf/531491 Add multicall support to xmlrpclib (2002-03-18) http://python.org/sf/531629 binary packagers (2002-03-19) http://python.org/sf/531901 fix xmlrpclib float marshalling bug (2002-03-19) http://python.org/sf/532180 Better AttributeError formatting (2002-03-20) http://python.org/sf/532638 specifying headers for extensions (2002-03-21) http://python.org/sf/533008 Silence AIX C Compiler Warnings. (2002-03-21) http://python.org/sf/533070 small seek tweak upon reads (gzip) (2002-03-22) http://python.org/sf/533482 Apply semaphore code to Cygwin (2002-03-22) http://python.org/sf/533681

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Re: PEP 282 comments
by Kevin Butler March 24, 2002

March 24, 2002

[Guido] > Here's another way to look at it. To support the base functionality, > we need an X amount of code. To add the feature of logging exceptions > at any level, we would need an additional Y amount. The number Y is > much smaller than X, but not insignificant. If the size of a subclass > that adds that feature is approximately equal to Y, I think it should > be kept out of the base class in this case, because you can easily > write that subclass for Zope. If writing such a subclass would > require significantly more code than Y (the amount of code needed to > integrate it directly into the base class), I agree that the base > class needs to be reworked to make this easier to add, or even to > support it outright. But I find that hard to believe in this case. I quite like this standard in general. Then I applied it to adding the **kwargs for exc_info to Vinay's logging module 0.4, and found that adding **kwargs to the convenience methods saved 143 bytes compared to the 0.4 implementation with its single "logException" method. Each convenience method: def fatal(self, msg, *args): """ Log 'msg % args' with severity 'FATAL'. """ if self.manager.disable >= FATAL: return if FATAL >= self.getChainedPriority(): self._log(FATAL, msg, args, None) gets **kwargs and replaces the final "None" with **kwargs: def fatal(self, msg, *args, **kwargs): ... self._log(FATAL, msg, args, **kwargs) logException goes away, taking its "sore thumb" name & usage with it. My experience suggests we use Vinay's exception( lvl, msg, *args ) to automagically call sys.exc_info() at different log levels, but including that change skews the results because of Vinay's shorter comment. :-) The signature of _log changes from: def _log(self, lvl, msg, args, exc_info): to: def _log(self, lvl, msg, args, exc_info=None): Simple usage & test cases work exactly as they did before, plus Jeremy & I are very happy with our "advanced" applications, and the "simple subclass" now just needs to override _log to do advanced things with other optional arguments. If you can provide a simple standard that supports both simple and advanced applications with equal facility, and you can save code by doing it without sacrificing readability, why in the world would you want to require multiple users to add subclasses that just duplicate the standard library methods with such a slight change? [Guido] "/The joy of coding Python should be in seeing short, concise, readable classes that express a lot of action in a small amount of clear code -- not in reams of trivial code that bores the reader to death./" :-) kb PS. Adding the straightforward subclass LoggerX to provide the functionality adds an extra 1.5K of code, all of it (except those negative 143 bytes) copied directly from Logger. Duplication of code is evil.

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March 24, 2002

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[development doc updates]
by Fred L. Drake March 24, 2002

March 24, 2002

The development version of the documentation has been updated: http://python.sourceforge.net/csstest-docs/ This is a test version of some style changes. The changes are localized to the navigation areas (I hope!), and probably only work for the browsers with the most-compliant CSS2 implementations. I've tested this with Mozilla 0.9.9 and MSIE 6 -- and it only worked in Mozilla. This isn't going to be usable until more browsers support the CSS needed to make this work, but I've never seen this done without frames before now (though I've played with the idea several times over the last couple of years). If you can't tell what the changes are, visit a page that needs to be scrolled to see the whole thing, and try scrolling it! Comments are welcome; send to python-docs(a)python.org.

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Re: [Python-Dev] Debug entry points for PyMalloc
by Michael Hudson March 24, 2002

March 24, 2002

Tim Peters <tim.one(a)comcast.net> writes: > [Michael Hudson] > > ... > > Presuambly it would be possible to do this wrapped around malloc() & > > free() too? > > Provided they were spelled PyMem_Malloc etc, sure. The debug routines as > sketched don't make any secret assumptions about the underlying allocators > they call. That's what I thought. > > No real point, I guess. > > There may be an excellent point to it: one of the pad bytes could be used > to record which "API family" a block of memory came from. Then a > mismatching realloc/free could be caught directly at the time it happened. Good point! > >> + The Debug free first uses the address to find the number of bytes > >> originally asked for, then checks the 8 bytes on each end for > >> sanity (in particular, that the PYMALLOC_FORBIDDENBYTEs are still > >> intact). > >> XXX Make this checking a distinct entry point. > > > Yes. Particularly if you can call it from gdb. > > Is something extraordinary required to make that possible? I had in mind > nothing fancier than > > extern void _PyMalloc_DebugCheckAddress(void* p); Dunno. I ought to learn how to use gdb properly. [...] > > ... > > What are you waiting for? <wink> > > For endless silly objections to fade away <wink>. Well, if you consider my comments to be objections, feel free to consider them to be written in very faint writing :) Cheers, M. -- While preceding your entrance with a grenade is a good tactic in Quake, it can lead to problems if attempted at work. -- C Hacking -- http://home.xnet.com/~raven/Sysadmin/ASR.Quotes.html

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Re: [Python-Dev] asyncore 2.1.1/2.2 incompatibility
by Zooko March 24, 2002

March 24, 2002

[add Cc: taral(a)taral.net, the author of an alternative to asyncore.py] GvR wrote: > > I think a way to tell asyncore to exit its loop on the next iteration > is still a good idea, but as it's a feature, I don't think it should > be added to any revision before 2.3. When we used asyncore in Mojo Nation, we ended up writing a wrapper around it. Here's the source: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/pyutil/pyutil/pyutilasync.py… When this happens, I think it's worth examining if some of the functionality of the wrapper deserve to be in the standard library. In particular, we added a way to tell asyncore to exit after the next select returns and is processed. We also added a way to trigger the current select from a different thread so that our newly ready writer could get started. We also added a simple FIFO event queue for arbitrary functions to be invoked from the asyncore thread. BTW, I intend to try an alternative to asyncore.py, written by taral(a)taral.net if I have time to experiment with it. This alternative uses an interface in which the higher-level code registers and unregisters, instead of the asyncore interface in which the lower level code polls the higher level asking "Now are you ready? Now are you ready?". This change will hopefully eliminate the last performance hotspot in my comms code as identified by profiling. (It will also, I think, clear the way for an implementation of the async module which uses nice new async I/O like FreeBSD's kqueue for excellent performance.) Regards, Zooko --- zooko.com Security and Distributed Systems Engineering ---

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