Mailman 3 May 2015 - Python-Dev

Single-file Python executables (was: Computed Goto dispatch for Python 2)
by Steve Dower May 30, 2015

May 30, 2015

Donald Stufft wrote: > Well Python 3.4.3 binary is 4kb for me, so you'd have that + your 1KB Python script + whatever other pieces you need. For contrast, here are the things you need on Windows to be able to get to an interactive prompt (I don't know how other platforms get this down to 4KB...): * python.exe (or some equivalent launcher) 39KB * python35.dll 3,788KB * vcruntime140.dll 87KB (the rest of the CRT is about 1MB, but is not redistributable so doesn't count here) * 26 files in Lib 343KB This gets you to ">>>", and basically everything after that is going to fail for some reason. That's an unavoidable 4,257KB. The rest of the stdlib adds another ~16MB once you exclude the test suite, so a fully functioning Python is not cheap. (Using compressed .pyc's in a zip file can make a big difference here though, assuming you're willing to trade CPU for HDD.) Cheers, Steve

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Summary of Python tracker Issues
by Python tracker May 29, 2015

May 29, 2015

ACTIVITY SUMMARY (2015-05-22 - 2015-05-29) Python tracker at http://bugs.python.org/ To view or respond to any of the issues listed below, click on the issue. Do NOT respond to this message. Issues counts and deltas: open 4844 (+11) closed 31241 (+47) total 36085 (+58) Open issues with patches: 2217 Issues opened (38) ================== #23970: Update distutils.msvccompiler for VC14 http://bugs.python.org/issue23970 reopened by benjamin.peterson #23996: _PyGen_FetchStopIterationValue() crashes on unnormalised excep http://bugs.python.org/issue23996 reopened by scoder #24267: test_venv.EnsurePipTest.test_with_pip triggers version check o http://bugs.python.org/issue24267 opened by vadmium #24270: PEP 485 (math.isclose) implementation http://bugs.python.org/issue24270 opened by ncoghlan #24272: PEP 484 docs http://bugs.python.org/issue24272 opened by gvanrossum #24274: erroneous comments in dictobject.c http://bugs.python.org/issue24274 opened by Jim.Jewett #24277: Take the new email package features out of provisional status http://bugs.python.org/issue24277 opened by r.david.murray #24278: Docs on Parsing arguments should say something about mem mgmt http://bugs.python.org/issue24278 opened by blais #24279: Update test_base64 to use test.support.script_helper http://bugs.python.org/issue24279 opened by bobcatfish #24280: Unable to install Python http://bugs.python.org/issue24280 opened by Jeff77789 #24284: Inconsistency in startswith/endswith http://bugs.python.org/issue24284 opened by serhiy.storchaka #24287: Let ElementTree prolog include comments and processing instruc http://bugs.python.org/issue24287 opened by rhettinger #24290: c_uint32 bitfields break structures http://bugs.python.org/issue24290 opened by Rony Batista #24291: wsgiref.handlers.SimpleHandler truncates large output blobs http://bugs.python.org/issue24291 opened by Jonathan Kamens #24292: wsgiref.simple_server.WSGIRequestHandler doesn't log request t http://bugs.python.org/issue24292 opened by Jonathan Kamens #24294: DeprecationWarnings should be visible by default in the intera http://bugs.python.org/issue24294 opened by njs #24295: Backport of #17086 causes regression in setup.py http://bugs.python.org/issue24295 opened by moritzs #24296: Queue documentation note needed http://bugs.python.org/issue24296 opened by Sandy Chapman #24299: 2.7.10 test__locale.py change breaks on Solaris http://bugs.python.org/issue24299 opened by jbeck #24300: Code Refactoring in function nis_mapname() http://bugs.python.org/issue24300 opened by pankaj.s01 #24301: gzip module failing to decompress valid compressed file http://bugs.python.org/issue24301 opened by Eric Gorr #24302: Dead Code of Handler check in function faulthandler_fatal_erro http://bugs.python.org/issue24302 opened by pankaj.s01 #24303: OSError 17 due to _multiprocessing/semaphore.c assuming a one- http://bugs.python.org/issue24303 opened by Paul Hobbs #24305: The new import system makes it impossible to correctly issue a http://bugs.python.org/issue24305 opened by njs #24306: Backport py.exe to 3.4 http://bugs.python.org/issue24306 opened by steve.dower #24307: pip error on windows whose current user name contains non-asci http://bugs.python.org/issue24307 opened by tanbro-liu #24308: Test failure: test_with_pip (test.test_venv.EnsurePipTest in 3 http://bugs.python.org/issue24308 opened by koobs #24309: string.Template should be using str.format and/or deprecated http://bugs.python.org/issue24309 opened by vlth #24310: Idle documentation -- what to do if you do not see an undersco http://bugs.python.org/issue24310 opened by lac #24313: json fails to serialise numpy.int64 http://bugs.python.org/issue24313 opened by thomas-arildsen #24314: irrelevant cross-link in documentation of user-defined functio http://bugs.python.org/issue24314 opened by july #24317: Change installer Customize default to match quick settings http://bugs.python.org/issue24317 opened by steve.dower #24318: Better documentaiton of profile-opt (and release builds in gen http://bugs.python.org/issue24318 opened by skip.montanaro #24319: Crash during "make coverage-report" http://bugs.python.org/issue24319 opened by skip.montanaro #24320: Remove a now-unnecessary workaround from importlib._bootstrap. http://bugs.python.org/issue24320 opened by eric.snow #24322: Hundreds of linker warnings on Windows http://bugs.python.org/issue24322 opened by BreamoreBoy #24323: Typo in Mutable Sequence Types documentation. http://bugs.python.org/issue24323 opened by eimista #24324: Remove -Wunreachable-code flag http://bugs.python.org/issue24324 opened by skip.montanaro Most recent 15 issues with no replies (15) ========================================== #24324: Remove -Wunreachable-code flag http://bugs.python.org/issue24324 #24322: Hundreds of linker warnings on Windows http://bugs.python.org/issue24322 #24319: Crash during "make coverage-report" http://bugs.python.org/issue24319 #24317: Change installer Customize default to match quick settings http://bugs.python.org/issue24317 #24307: pip error on windows whose current user name contains non-asci http://bugs.python.org/issue24307 #24303: OSError 17 due to _multiprocessing/semaphore.c assuming a one- http://bugs.python.org/issue24303 #24302: Dead Code of Handler check in function faulthandler_fatal_erro http://bugs.python.org/issue24302 #24300: Code Refactoring in function nis_mapname() http://bugs.python.org/issue24300 #24292: wsgiref.simple_server.WSGIRequestHandler doesn't log request t http://bugs.python.org/issue24292 #24280: Unable to install Python http://bugs.python.org/issue24280 #24277: Take the new email package features out of provisional status http://bugs.python.org/issue24277 #24274: erroneous comments in dictobject.c http://bugs.python.org/issue24274 #24265: IDLE produces error message when run with both -s and -c. http://bugs.python.org/issue24265 #24264: imageop Unsafe Arithmetic http://bugs.python.org/issue24264 #24263: Why VALID_MODULE_NAME in unittest/loader.py is r'[_a-z]\w*\.py http://bugs.python.org/issue24263 Most recent 15 issues waiting for review (15) ============================================= #24318: Better documentaiton of profile-opt (and release builds in gen http://bugs.python.org/issue24318 #24314: irrelevant cross-link in documentation of user-defined functio http://bugs.python.org/issue24314 #24303: OSError 17 due to _multiprocessing/semaphore.c assuming a one- http://bugs.python.org/issue24303 #24302: Dead Code of Handler check in function faulthandler_fatal_erro http://bugs.python.org/issue24302 #24300: Code Refactoring in function nis_mapname() http://bugs.python.org/issue24300 #24299: 2.7.10 test__locale.py change breaks on Solaris http://bugs.python.org/issue24299 #24295: Backport of #17086 causes regression in setup.py http://bugs.python.org/issue24295 #24287: Let ElementTree prolog include comments and processing instruc http://bugs.python.org/issue24287 #24284: Inconsistency in startswith/endswith http://bugs.python.org/issue24284 #24279: Update test_base64 to use test.support.script_helper http://bugs.python.org/issue24279 #24278: Docs on Parsing arguments should say something about mem mgmt http://bugs.python.org/issue24278 #24272: PEP 484 docs http://bugs.python.org/issue24272 #24270: PEP 485 (math.isclose) implementation http://bugs.python.org/issue24270 #24266: raw_input + readline: Ctrl+C during search breaks readline http://bugs.python.org/issue24266 #24259: tar.extractall() does not recognize unexpected EOF http://bugs.python.org/issue24259 Top 10 most discussed issues (10) ================================= #16991: Add OrderedDict written in C http://bugs.python.org/issue16991 28 msgs #24244: Python exception on strftime with %f on Python 3 and Python 2 http://bugs.python.org/issue24244 27 msgs #24270: PEP 485 (math.isclose) implementation http://bugs.python.org/issue24270 21 msgs #24259: tar.extractall() does not recognize unexpected EOF http://bugs.python.org/issue24259 14 msgs #21998: asyncio: support fork http://bugs.python.org/issue21998 13 msgs #24294: DeprecationWarnings should be visible by default in the intera http://bugs.python.org/issue24294 9 msgs #14373: C implementation of functools.lru_cache http://bugs.python.org/issue14373 8 msgs #24260: TabError behavior doesn't match documentation http://bugs.python.org/issue24260 8 msgs #23970: Update distutils.msvccompiler for VC14 http://bugs.python.org/issue23970 7 msgs #24254: Make class definition namespace ordered by default http://bugs.python.org/issue24254 7 msgs Issues closed (46) ================== #11205: Evaluation order of dictionary display is different from refer http://bugs.python.org/issue11205 closed by python-dev #18032: Optimization for set/frozenset.issubset() http://bugs.python.org/issue18032 closed by rhettinger #18459: readline: libedit support on non-apple platforms http://bugs.python.org/issue18459 closed by vadmium #20035: Clean up Tcl library discovery in Tkinter on Windows http://bugs.python.org/issue20035 closed by zach.ware #21448: Email Parser use 100% CPU http://bugs.python.org/issue21448 closed by rhettinger #21961: Add What's New for Idle. http://bugs.python.org/issue21961 closed by terry.reedy #22189: collections.UserString missing some str methods http://bugs.python.org/issue22189 closed by rhettinger #22931: cookies with square brackets in value http://bugs.python.org/issue22931 closed by python-dev #22955: Pickling of methodcaller, attrgetter, and itemgetter http://bugs.python.org/issue22955 closed by serhiy.storchaka #23086: Add start and stop parameters to the Sequence.index() ABC mixi http://bugs.python.org/issue23086 closed by rhettinger #23270: Use the new __builtin_mul_overflow() of Clang and GCC 5 to che http://bugs.python.org/issue23270 closed by haypo #23359: Speed-up set_lookkey() http://bugs.python.org/issue23359 closed by rhettinger #23509: Speed up Counter operators http://bugs.python.org/issue23509 closed by rhettinger #23574: datetime: support leap seconds http://bugs.python.org/issue23574 closed by haypo #23648: PEP 475 meta issue http://bugs.python.org/issue23648 closed by haypo #23712: Experiment: Assume that exact unicode hashes are perfect disc http://bugs.python.org/issue23712 closed by rhettinger #23754: Add a new os.read_into() function to avoid memory copies http://bugs.python.org/issue23754 closed by haypo #23840: tokenize.open() leaks an open binary file on TextIOWrapper err http://bugs.python.org/issue23840 closed by haypo #23955: Add python.ini file for embedded/applocal installs http://bugs.python.org/issue23955 closed by steve.dower #23993: Use surrogateescape error handler by default in open() if the http://bugs.python.org/issue23993 closed by haypo #24199: Idle: remove idlelib.idlever.py and its use in About dialog http://bugs.python.org/issue24199 closed by python-dev #24204: string.strip() documentation is misleading http://bugs.python.org/issue24204 closed by rhettinger #24219: Repeated integer in Lexical analysis/Integer literals section http://bugs.python.org/issue24219 closed by rhettinger #24230: tempfile.mkdtemp() doesn't work with bytes paths http://bugs.python.org/issue24230 closed by gregory.p.smith #24268: PEP 489 -- Multi-phase extension module initialization http://bugs.python.org/issue24268 closed by ncoghlan #24269: Few improvements to the collections documentation http://bugs.python.org/issue24269 closed by rhettinger #24271: Python site randomly scrolls up when on mobile. http://bugs.python.org/issue24271 closed by ned.deily #24273: _scproxy.so causes EXC_BAD_ACCESS (SIGSEGV) http://bugs.python.org/issue24273 closed by ned.deily #24275: lookdict_* give up too soon http://bugs.python.org/issue24275 closed by benjamin.peterson #24276: Correct reuse argument tuple in property descriptor http://bugs.python.org/issue24276 closed by serhiy.storchaka #24281: String formatting: incorrect number of decimal places http://bugs.python.org/issue24281 closed by r.david.murray #24282: 3.5 gdbm extension build fails with "'clinic/_gdbmmodule.c.h' http://bugs.python.org/issue24282 closed by ned.deily #24283: Print not safe in signal handlers http://bugs.python.org/issue24283 closed by pitrou #24285: regression for importing extensions in packages http://bugs.python.org/issue24285 closed by berker.peksag #24286: Should OrderedDict.viewitems compare equal to dict.viewitems w http://bugs.python.org/issue24286 closed by rhettinger #24288: Include/opcode.h is modified during building http://bugs.python.org/issue24288 closed by serhiy.storchaka #24289: can't start Python3 due to ImportError of copy_reg http://bugs.python.org/issue24289 closed by r.david.murray #24293: Windows installer unreadable with std/custom themes http://bugs.python.org/issue24293 closed by steve.dower #24297: Lib/symbol.py is out of sync with Grammar/Grammar http://bugs.python.org/issue24297 closed by yselivanov #24298: inspect.signature includes bound argument for wrappers around http://bugs.python.org/issue24298 closed by yselivanov #24304: Documentation broken link to license http://bugs.python.org/issue24304 closed by ned.deily #24311: urllib2.urlopen() through proxy fails when HTTPS URL contains http://bugs.python.org/issue24311 closed by serhiy.storchaka #24312: miniDOM._write_data() give a vague error message when the argu http://bugs.python.org/issue24312 closed by serhiy.storchaka #24315: collections.abc: Coroutine should be derived from Awaitable http://bugs.python.org/issue24315 closed by yselivanov #24316: Fix types.coroutine to accept objects from Cython http://bugs.python.org/issue24316 closed by yselivanov #24321: interaction of nonlocal and except leading to incorrect behavi http://bugs.python.org/issue24321 closed by ned.deily

1 0

Not getting the exact file to start
by Saket Sourav May 29, 2015

May 29, 2015

Hello sir. I have just installed python 3.4.2. I'm not getting the file 'IDLE (python GUI)' to start programming. Or which file I should open to write code

2 1

Preserving the definition order of class namespaces.
by Eric Snow May 29, 2015

May 29, 2015

tl;dr Are there any objections to making making the default cls.__prepare__ return OrderedDict instead of dict (and preserve that order in a list on the class)? A couple years ago [1][2] I proposed making class definition namespaces use OrderedDict by default. Said Guido [3]: I'm fine with doing this by default for a class namespace; the type of cls.__dict__ is already a non-dict (it's a proxy) and it's unlikely to have 100,000 entries. It turns out making cls.__dict__ an OrderedDict isn't reasonably tractable (due to the concrete API v. subclasses), but really that isn't what I was looking for anyway. Regardless, since it's been a while I just want to run the proposal by the group again. I'm hopeful about landing my C implementation of OrderedDict [4] in the next few days. Also, I have a patch up [5] that implements using OrderedDict for class definitions. So mostly I just want to double check that I'm still good to go. Just to be clear on what I'm proposing specifically, I've summed it up below. -eric --------------------- Currently if you want to preserve the order of a class definition you have to use a metaclass with a __prepare__ method (see PEP 3115). However, as that PEP points out [6], the common case for __prepare__ is to use OrderedDict. I'm proposing that we return OrderedDict() by default from __prepare__. Considering the common case, we should also expose that definition order on the class afterward since otherwise the extra information from the class definition namespace is discarded (type.__new__ copies it into a dict which is then used for cls.__dict__). So the key changes are: * use OrderedDict by default for class definition namespace (e.g. from type.__prepare__) * expose that definition order as cls.__definition_order__ (a list) (Note that I will not be changing the actual type of cls.__dict__ (i.e. tp_dict) which will remain a dict.) The effect of the change would be that the following are basically equivalent (relative to the the definition namespace): class Meta(type): @classmethod. def __prepare__(meta, *args, **kwargs): return OrderedDict() class SpamOld(metaclass=Meta): a = 1 b = 2 c = 3 __definition_order__ = list(locals()) class SpamNew: a = 1 b = 2 c = 3 assert SpamOld.__definition__order == SpamNew.__definition_order__ The key differences are: * for SpamNew you don't need to use a metaclass [7][8] * for SpamNew you don't need to rely on the behavior of locals() * for SpamNew the class definition isn't cluttered with extra boilerplate for __definition_order__ * class decorators that care about definition order [9] don't have to require that classes like SpamNew manually preserve that order somehow The patch for the change is pretty minimal. [5] Also, Nick Coghlan recently expressed that he favored using OrderedDict by default over the alternative presented by PEP 422/487. [10] [1] https://mail.python.org/pipermail/python-ideas/2013-February/019690.html [2] https://mail.python.org/pipermail/python-dev/2013-June/127103.html [3] Guido: https://mail.python.org/pipermail/python-ideas/2013-February/019704.html [4] http://bugs.python.org/issue16991 [5] http://bugs.python.org/issue24254 [6] see the "Alternate Proposals" section of https://www.python.org/dev/peps/pep-3115/ [7] PEPs 422 and 487 relatedly focus on the benefits of reducing the need to use metaclasses [8] https://mail.python.org/pipermail/python-ideas/2013-February/019706.html [9] see "Key points" on https://mail.python.org/pipermail/python-dev/2013-February/124439.html [10] Nick: https://mail.python.org/pipermail/python-ideas/2015-March/032254.html

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Python 3.5 schedule addendum adding a new Python 3.5.0 beta, this weekend
by Larry Hastings May 29, 2015

May 29, 2015

On behalf of the Python 3.5 release team: Due to a particularly bad bug ( http://bugs.python.org/issue24285 ), we're going to issue a new beta of Python 3.5 this weekend. This will not change the rest of the schedule; it'll just bump the remaining beta numbers up by 1. Thus the schedule is now as follows: - 3.5.0 beta 1: May 24, 2015 - 3.5.0 beta 2: May 31, 2015 - 3.5.0 beta 3: July 5, 2015 - 3.5.0 beta 4: July 26, 2015 - 3.5.0 candidate 1: August 9, 2015 - 3.5.0 candidate 2: August 23, 2015 - 3.5.0 candidate 3: September 6, 2015 - 3.5.0 final: September 13, 2015 May you live in interesting times, //arry/

1 0

Usability of the limited API
by Paul Moore May 28, 2015

May 28, 2015

With Python 3.5 shipping an embeddable copy of the interpreter on Windows, I thought I'd try out a simple embedded interpreter as an experiment. I wanted to use the limited API, as I'd rather it were easy to upgrade the interpreter without recompiling the embedding app. But the "Very high-level embedding" example in the docs doesn't compile with the limited API. #include <Python.h> int main(int argc, char *argv[]) { wchar_t *program = Py_DecodeLocale(argv[0], NULL); if (program == NULL) { fprintf(stderr, "Fatal error: cannot decode argv[0]\n"); exit(1); } Py_SetProgramName(program); /* optional but recommended */ Py_Initialize(); PyRun_SimpleString("from time import time,ctime\n" "print('Today is', ctime(time()))\n"); Py_Finalize(); PyMem_RawFree(program); return 0; } The Py_DecodeLocale/Py_SetProgramName/PyMem_RawFree bit can probably be replaced by a Py_SetProgramName call specifying a static value, it's not exactly crucial. (Py_DecodeLocale appears to be defined as in the limited API by the headers, but not exported from python3.dll, by the way, which implies that something's out of sync). But PyRun_SimpleString doesn't appear to be exposed in the limited API, even though https://docs.python.org/3/c-api/veryhigh.html doesn't mention this, and https://docs.python.org/3/c-api/stable.html says that functions not part of the stable API will be marked as such. I dumped out the exported symbols from python3.dll, which is the simplest way I could think of finding out what is in the limited API (it's hardly user friendly, but never mind). And frustratingly, none of the very high level PyRun_XXX APIs are available. At this point, I think I'll probably just give up and use the full API, but it does make me question whether the limited API is actually usable as it stands. I was hoping to be able to suggest as an application bundling option that people could write a trivial wrapper script in C to fire up a Python script, and bundle that along with its dependencies and the embeddable Python distribution. Looks like that's doable, but only using the full API, which makes upgrading the bundled Python interpreter a bit messier. Ah, well, no huge loss :-( But after this experiment, I do wonder - is the limited API really a viable option for embedders? Paul

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Re: [Python-Dev] cpython (3.5): remove STORE_MAP, since it's unused
by Serhiy Storchaka May 28, 2015

May 28, 2015

On 28.05.15 22:40, benjamin.peterson wrote: > https://hg.python.org/cpython/rev/ac891c518d4e > changeset: 96342:ac891c518d4e > branch: 3.5 > parent: 96339:6f05f83c7010 > user: Benjamin Peterson <benjamin(a)python.org> > date: Thu May 28 14:40:08 2015 -0500 > summary: > remove STORE_MAP, since it's unused Wouldn't it break support of .pyc files compiled with older versions of Python 3?

3 2

Issue 24285: regression for importing extensions in packages
by Ned Batchelder May 28, 2015

May 28, 2015

This issue has been fixed, but a day or two late for 3.5b1. It prevents loading the coverage.py extension. It'd be great to get a new beta release soon. :) --Ned.

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Embedded Python. Debug Version and _ctypes
by Uladzimir Kryvian May 27, 2015

May 27, 2015

Hi! I'm trying to use embedding of Python in my program. Simple C-program, compiled in Debug, that uses py-script that just imports "ctypes" gives me an error about "no module named "_ctypes". How to compile python lib in Visual Studio statically with ctypes support? Or how to use shared ctypes lib in debug mode?

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Re: [Python-Dev] [Python-checkins] cpython (3.4): Issue #23840: tokenize.open() now closes the temporary binary file on error to
by Yury Selivanov May 26, 2015

May 26, 2015

On 2015-05-26 12:26 AM, Terry Reedy wrote: >> + try: >> + encoding, lines = detect_encoding(buffer.readline) >> + buffer.seek(0) >> + text = TextIOWrapper(buffer, encoding, line_buffering=True) >> + text.mode = 'r' >> + return text >> + except: >> + buffer.close() >> + raise > > Please do not add bare 'except:'. If you mean 'except > BaseException:', say so. try..finally would be even better. Yury

4 5