Mailman 3 June 2013 - Python-Dev

python symbolizition
by Pynix Wang 14 Jun '13

14 Jun '13

1.lambda expression c# a.(x, y) => x == y b.() => SomeMethod() ruby: -> {|msg| puts msg} python can use c# like and remove "lambda" keyword. 2.global variable ruby $glo_var python can use $ or @ or another and remove "global".

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Re: [Python-Dev] cpython: Move test_pep352 over to unittest.main()
by Serhiy Storchaka 14 Jun '13

14 Jun '13

14.06.13 04:18, brett.cannon написав(ла): > http://hg.python.org/cpython/rev/af27c661d4fb > changeset: 84115:af27c661d4fb > user: Brett Cannon <brett(a)python.org> > date: Thu Jun 13 21:18:43 2013 -0400 > summary: > Move test_pep352 over to unittest.main() You forgot about: from test.support import run_unittest

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Re: [Python-Dev] cpython: fixd refleak
by Antoine Pitrou 13 Jun '13

13 Jun '13

On Mon, 10 Jun 2013 10:47:28 +0200 (CEST) christian.heimes <python-checkins(a)python.org> wrote: > http://hg.python.org/cpython/rev/6860263c05b3 > changeset: 84077:6860263c05b3 > user: Christian Heimes <christian(a)cheimes.de> > date: Mon Jun 10 10:47:22 2013 +0200 > summary: > fixd refleak > [...] > - return Py_BuildValue("(OOOO)", ofile_env, ofile, odir_env, odir); > + if ((tup = PyTuple_New(4)) == NULL) { > + goto error; > + } > + PyTuple_SET_ITEM(tup, 0, ofile_env); > + PyTuple_SET_ITEM(tup, 1, ofile); > + PyTuple_SET_ITEM(tup, 2, odir_env); > + PyTuple_SET_ITEM(tup, 3, odir); > + return tup; How about return Py_BuildValue("NNNN", ofile_env, ofile, odir_env, odir); ?

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ssl improvements and testing question
by Christian Heimes 13 Jun '13

13 Jun '13

Hi, I'm working on a couple of improvements for the ssl module: http://bugs.python.org/issue17134 http://bugs.python.org/issue18138 http://bugs.python.org/issue18143 http://bugs.python.org/issue18147 #17134 is going to provide a way to use Window's crypt32.dll to load CA certs from Window's CA cert storage. I have a working proof of concept [1] that uses ctypes to interface crypt32.dll. I'll reimplement the code in C. #18138 implements the bits and pieces for #17134 in order to add DER and PEM certs from memory (ASCII unicode or Py_Buffer). Until now the ssl module can only load files from the file system. #18143 and #18147 are diagnostic and debugging helpers that I would like to add. The SSLContext() object is black box. You stuff in some PEM files and don't know which CA certs have been loaded. The enhancements implement a function to retrieve a list of CA certs (same format as getpeercert()) and list of default CA locations for the platform. I'm also thinking about OCSP support and X509v3 extension support for _decode_certificate(). Both are a PITB ... Python has an easier and better documented C API. Question: What's the minimum version of OpenSSL Python 3.4 is going to support? Do we have an easy way to compile and link Python against a custom installation of OpenSSL or do I have to fiddle around with CPPFLAGS and CFLAGS? Christian [1] https://pypi.python.org/pypi/wincertstore

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Enhancement of Python memory allocators
by Victor Stinner 13 Jun '13

13 Jun '13

Hi, I would like to improve memory allocators of Python. My two use cases are replacing memory allocators with custom allocators in embedded system and hooking allocators to track usage of memory. I wrote a patch for this, I'm going to commit it if nobody complains: http://bugs.python.org/issue3329 Using this patch, detecting memory corruptions (buffer underflow and overflow) can be done without recompilation. We may add an environment variable to enable Python debug functions at runtime, example: PYDEBUGMALLOC=1. There is just a restriction: the environment variable would not be ignored with -E command line option, because command line options are parsed after the first memory allocation. What do you think? ***** The patch adds the following functions: void PyMem_GetAllocators( void **ctx_p, void* (**malloc_p) (void *ctx, size_t size), void* (**realloc_p) (void *ctx, void *ptr, size_t size), void (**free_p) (void *ctx, void *ptr)); void PyMem_SetAllocators( void *ctx, void* (*malloc) (void *ctx, size_t size), void* (*realloc) (void *ctx, void *ptr, size_t size), void (*free) (void *ctx, void *ptr)); It adds 4 similar functions (get/set) for PyObject_Malloc() and allocators of pymalloc arenas. ***** For the "track usage of memory" use case, see the following project which hooks memory allocators using PyMem_SetAllocators() and PyObject_SetAllocators() to get allocated bytes per filename and line number. https://pypi.python.org/pypi/pytracemalloc ***** Another issue proposes to use VirtualAlloc() and VirtualFree() for pymalloc arenas, see: http://bugs.python.org/issue13483 I don't know if it would be interesting, but it would now possible to choose the memory allocator (malloc, mmap, HeapAlloc, VirtualAlloc, ...) at runtime, with an environment variable for example. Victor

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Re: [Python-Dev] [Python-checkins] cpython: Move test___all__ over to unittest.main() and use ModuleNotFoundError
by Brett Cannon 12 Jun '13

12 Jun '13

Obviously the commit message is a little misleading since changes I was about to stage accidentally went in on this change. Sorry about that. Same basic concept of the changes, just to more modules. On Wed, Jun 12, 2013 at 8:12 PM, brett.cannon <python-checkins(a)python.org>wrote: > http://hg.python.org/cpython/rev/c4d7228421df > changeset: 84106:c4d7228421df > user: Brett Cannon <brett(a)python.org> > date: Wed Jun 12 20:12:30 2013 -0400 > summary: > Move test___all__ over to unittest.main() and use ModuleNotFoundError > > files: > Lib/test/regrtest.py | 16 ++++++++-------- > Lib/test/support.py | 14 +++++++------- > Lib/test/test___all__.py | 7 ++----- > Lib/xmlrpc/server.py | 2 +- > Lib/zipfile.py | 6 +++--- > 5 files changed, 21 insertions(+), 24 deletions(-) > > > diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py > --- a/Lib/test/regrtest.py > +++ b/Lib/test/regrtest.py > @@ -146,11 +146,11 @@ > > try: > import threading > -except ImportError: > +except ModuleNotFoundError: > threading = None > try: > import multiprocessing.process > -except ImportError: > +except ModuleNotFoundError: > multiprocessing = None > > > @@ -180,7 +180,7 @@ > if sys.platform == 'darwin': > try: > import resource > - except ImportError: > + except ModuleNotFoundError: > pass > else: > soft, hard = resource.getrlimit(resource.RLIMIT_STACK) > @@ -571,7 +571,7 @@ > if findleaks: > try: > import gc > - except ImportError: > + except ModuleNotFoundError: > print('No GC available, disabling findleaks.') > findleaks = False > else: > @@ -692,7 +692,7 @@ > if use_mp: > try: > from threading import Thread > - except ImportError: > + except ModuleNotFoundError: > print("Multiprocess option requires thread support") > sys.exit(2) > from queue import Queue > @@ -1396,7 +1396,7 @@ > pic = sys.path_importer_cache.copy() > try: > import zipimport > - except ImportError: > + except ModuleNotFoundError: > zdc = None # Run unmodified on platforms without zipimport support > else: > zdc = zipimport._zip_directory_cache.copy() > @@ -1473,7 +1473,7 @@ > sys.path_importer_cache.update(pic) > try: > import zipimport > - except ImportError: > + except ModuleNotFoundError: > pass # Run unmodified on platforms without zipimport support > else: > zipimport._zip_directory_cache.clear() > @@ -1510,7 +1510,7 @@ > doctest.master = None > try: > import ctypes > - except ImportError: > + except ModuleNotFoundError: > # Don't worry about resetting the cache if ctypes is not supported > pass > else: > diff --git a/Lib/test/support.py b/Lib/test/support.py > --- a/Lib/test/support.py > +++ b/Lib/test/support.py > @@ -29,27 +29,27 @@ > > try: > import _thread, threading > -except ImportError: > +except ModuleNotFoundError: > _thread = None > threading = None > try: > import multiprocessing.process > -except ImportError: > +except ModuleNotFoundError: > multiprocessing = None > > try: > import zlib > -except ImportError: > +except ModuleNotFoundError: > zlib = None > > try: > import bz2 > -except ImportError: > +except ModuleNotFoundError: > bz2 = None > > try: > import lzma > -except ImportError: > +except ModuleNotFoundError: > lzma = None > > __all__ = [ > @@ -116,7 +116,7 @@ > with _ignore_deprecated_imports(deprecated): > try: > return importlib.import_module(name) > - except ImportError as msg: > + except ModuleNotFoundError as msg: > if sys.platform.startswith(tuple(required_on)): > raise > raise unittest.SkipTest(str(msg)) > @@ -188,7 +188,7 @@ > if not _save_and_block_module(blocked_name, orig_modules): > names_to_remove.append(blocked_name) > fresh_module = importlib.import_module(name) > - except ImportError: > + except ModuleNotFoundError: > fresh_module = None > finally: > for orig_name, module in orig_modules.items(): > diff --git a/Lib/test/test___all__.py b/Lib/test/test___all__.py > --- a/Lib/test/test___all__.py > +++ b/Lib/test/test___all__.py > @@ -75,7 +75,7 @@ > try: > import rlcompleter > import locale > - except ImportError: > + except ModuleNotFoundError: > pass > else: > locale.setlocale(locale.LC_CTYPE, 'C') > @@ -113,8 +113,5 @@ > print('Following modules failed to be imported:', > failed_imports) > > > -def test_main(): > - support.run_unittest(AllTest) > - > if __name__ == "__main__": > - test_main() > + unittest.main() > diff --git a/Lib/xmlrpc/server.py b/Lib/xmlrpc/server.py > --- a/Lib/xmlrpc/server.py > +++ b/Lib/xmlrpc/server.py > @@ -116,7 +116,7 @@ > import traceback > try: > import fcntl > -except ImportError: > +except ModuleNotFoundError: > fcntl = None > > def resolve_dotted_attribute(obj, attr, allow_dotted_names=True): > diff --git a/Lib/zipfile.py b/Lib/zipfile.py > --- a/Lib/zipfile.py > +++ b/Lib/zipfile.py > @@ -18,18 +18,18 @@ > try: > import zlib # We may need its compression method > crc32 = zlib.crc32 > -except ImportError: > +except ModuleNotFoundError: > zlib = None > crc32 = binascii.crc32 > > try: > import bz2 # We may need its compression method > -except ImportError: > +except ModuleNotFoundError: > bz2 = None > > try: > import lzma # We may need its compression method > -except ImportError: > +except ModuleNotFoundError: > lzma = None > > __all__ = ["BadZipFile", "BadZipfile", "error", > > -- > Repository URL: http://hg.python.org/cpython > > _______________________________________________ > Python-checkins mailing list > Python-checkins(a)python.org > http://mail.python.org/mailman/listinfo/python-checkins > >

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Doubly linked lists in Python core?
by Skip Montanaro 11 Jun '13

11 Jun '13

I encountered this disconcerting message yesterday on a Linux system running Python 2.7.2: *** glibc detected *** /opt/local/bin/python: corrupted double-linked list: 0x0000000003b01c90 *** Of course, no core file or other information about where the problem occurred was left behind, just the raw pointer value. Running under valgrind didn't report anything obvious, at least nothing different than a run with slightly different command line parameters which didn't elicit the message. I suspect the problem actually lies in one of our C++ libraries here at work, but before I attempt any debugging gymnastics (ow! my back hurts) I thought I would check to see if Python makes much use of double linked lists in a non-debug build. I don't recall a lot from days of yore, perhaps some in the dict implementation? Thanks, Skip

3 3

new Plan 9 (and family) port of v2.7.5
by Jeff Sickel 11 Jun '13

11 Jun '13

I have a set of patches I've developed based on the 2.7 branch that provides a working port of Python 2.7.5 to Plan 9 386 and amd64 builds (an arm version is mostly working, but will need a few more updates before being hauled off on the wagon). Most of the changes, including mkfiles, are local to a Plan9 subdirectory. There are a few changes to Lib/*.py files specifically site.py and sysconfig.py to make living in a semi-POSIX world tolerable with many current Python modules. Because Plan 9 does not have shared libraries, we must link in all the C modules we want at build time. This means that I've included specific targets to pull in Mercurial sources during the compilation and linking phases. That brings us up to a current version of Mercurial 2.6.2. There is no ssh support for cloning, but we do have a viable version of https: using TLS/SSLv3 that has worked well with bitbucket. That said, I can prepare a patch from my mq work area and submit it upstream in one of various ways for review. Is there a preferred method that does not require an initial `hg clone ssh://hg@hg.python.org/cpython`? acme# pwd /usr/jas/src/cmd/cpython acme# hg sum parent: 83814:75a6bbf41cc8 plan9 qbase qtip update setup base install locations branch: 2.7 commit: 8 unknown (clean) update: 37 new changesets, 2 branch heads (merge) mq: 1 applied ac -jas

2 1

Python 3 metaclasses, doctest, and unittest
by Ethan Furman 10 Jun '13

10 Jun '13

I just wanted to take a minute and say THANK YOU to everyone involved in getting Python 3 to where it is today. It is so much easier to use, especially metaclasses (nearly pulled my hair out trying to get Enum working on Py2!). Also a big thank you to the doctest folks as it was invaluable in getting my Py2 examples correct, and, of course, the unittest folks as I would have been lost without those. Thank you thank you thank you. -- ~Ethan~ P.S. I'll get a backported package on PyPI after the code commit for 3.4.

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Ordering keyword dicts
by Guido van Rossum 10 Jun '13

10 Jun '13

On Sat, May 18, 2013 at 10:27 PM, Raymond Hettinger <raymond.hettinger(a)gmail.com> wrote: > BTW, I'm +1 on the idea for ordering keyword-args. It makes > it easier to debug if the arguments show-up in the order they > were created. AFAICT, no purpose is served by scrambling them > (which is exacerbated by the new randomized hashing security feature). I'm slow at warming up to the idea. My main concern is speed -- since most code doesn't need it and function calls are already slow (and obviously very common :-) it would be a shame if this slowed down function calls that don't need it noticeably. An observation is that it's only necessary to preserve order if the function definition uses **kwds. AFAIK we currently don't know if this is the case when the call is made though, but perhaps the information could be made available to the call site somehow. There are also many special cases to consider; e.g. using **kwds in the call where kwds is an unordered dict, or calls from C, or calls to C. But maybe someone considers this a challenge and comes up with a patch? The benefits to *some* use cases would be obvious. -- --Guido van Rossum (python.org/~guido)

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