Mailman 3 March 2015 - Python-Dev

Asking for review for Windows issues 21518 and 22080
by Claudiu Popa 07 Mar '15

07 Mar '15

Hello, The winreg module has a function for loading a registry key under another registry key, called winreg.LoadKey. Unfortunately, the module doesn't provide a way to unload that key after the user finishes operating with it. There's a patch [1] for exporting the RegUnloadKey [2] API in winreg module as winreg.UnloadKey, similar to how RegLoadKey is exported as winreg.LoadKey. The patch is helped by another one [3], which provides a new module, test.support.windows_helper, for handling various issues on the Windows platform, such as acquiring or releasing a privilege. Unfortunately, it seems there's a dearth of reviewers for this platform. Could someone knowledgeable with Windows be so kind to review these patches? They could make a good addition for Python 3.5. Thank you very much. [1] http://bugs.python.org/issue21518 - Expose RegUnloadKey in winreg [2] https://msdn.microsoft.com/en-us/library/windows/desktop/ms724924%28v=vs.85… [3] http://bugs.python.org/issue22080 - Add windows_helper module helper /Claudiu

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Optimize binary insertion sort algorithm in Timsort.
by nha pham 07 Mar '15

07 Mar '15

This describes an optimization for "binary insertion sort" (BINSORT for short). BINSORT has been implemented in Python, CyThon, and Timsort (the default Array.sort() in JAVA SE 7 and JAVA SE 8) I have read the BINSORT in Timsort http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/8-b1… and I think that I can make a little more optimization. ================= The old BINSORT: The basic idea is to use binary search on the sorted list to find a final position for a new element X, then insert X to the sorted list. [SORTED_LIST], [X in UNSORTED_LIST] // pick X in UNSORTED_LIST index = binarySeach([SORTED_LIST]) // use binary search to find appropriate location for X in SORTED_LIST [SORTED_LIST].add(index, X) // insert X to index location ================== New BINSORT: [SORTED_LIST], [A] // A is an UNSORTED_LIST j = compare(A[i], A[i+1]) // pick A[i], compare to next element index = binarySeach([SORTED_LIST], A[i]) // use binary search to find // appropriate location for A[i] in SORTED_LIST, and remember the index [SORTED_LIST].add(index, A[i]) // insert A[i] to index location // Now for A[+1], where already know where it should be, compare to A[i] if j >= 0: // A[i] > A[i+1], so A[i+1] will be in the right side of A[i] // We only have to search on a reduced Array: index = binarySearch(SORTED_LIST[index : length(SORTED_LIST)], A[i+1]) else: // we search on the left side of of A[i] index = binarySearch(SORTED_LIST[0 : index], A[i+1]) [SORTED_LIST].add(index, A[i+1]) // insert A[i+1] to index location //repeat the loop ================== Run test. Intuitively, new BINSORT will be better if the Array become bigger, because it reduce the array to search with the cost of only 1 more comparison. I only care about small array, with the length < 100 (we have known that in Timsort, the list is divided to chunks with length 64, then apply BINSORT to them). So I make a big Array, divide them, and apply new BINSORT in each chunk, then compare to OLD BINSORT. The source code is in the bottom of this document. Here is the results: cpuinfo: model name : Intel(R) Core(TM) i3 CPU M 350 @ 2.27GHz stepping : 2 microcode : 0xc cpu MHz : 933.000 cache size : 3072 KB ----- random array: ARRAY_SIZE: 1000000 CHUNK_SIZE: 100 DATA: randint(0, 1000000) OLD BINSORT: 81.45754 new BINSORT: 5.26754 RATIO: (OLD - new) / new = 14.464 --- incremental array: ARRAY_SIZE: 1000000 CHUNK_SIZE: 100 DATA: range(0, 1000000) OLD BINSORT: 81.87927 new BINSORT: 5.41651 RATIO: (OLD - new) / new = 14.11659 --- decremental array: ARRAY_SIZE: 1000000 CHUNK_SIZE: 100 DATA: range(0, 1000000) OLD BINSORT: 81.45723 new BINSORT: 5.09823 RATIO: (OLD - new) / new = 14.97753 ---- all equal array: ARRAY_SIZE: 1000000 CHUNK_SIZE: 100 DATA: 50000 OLD BINSORT: 40.46027 new BINSORT: 5.41221 RATIO: (OLD - new) / new = 6.47573 ==================== What should we do next: - Tuning my test code (I have just graphed it). - Test other cases, and bigger array (my laptop cannot handle array more than 10^6.) - Modifying Timsort in java.util. and test if it is better. ==================== My test code, written by Python. from timeit import Timer setup ="""\ import bisect from random import randint from timeit import Timer SIZE = 1000000 CHUNK = 100 NUM_CHUNK = SIZE/CHUNK data = [] data2 = [] data3 = [] for i in range(0,SIZE): data.append(randint(0,1000000)) #data.append(i) #data = data[::-1] """ sample ="""\ for j in range(0,NUM_CHUNK): low = CHUNK*j high= low + CHUNK data2.append(data[low]) index = low for i in range(low,high): x = data[i] index = bisect.bisect_right(data2[low:], x, low, len(data2) - low-1) data2.insert(index, x) """ new ="""\ for j in range(0,NUM_CHUNK): low = CHUNK*j high= low + CHUNK data3.append(data[low]) index = low for i in range(low,high): x = data[i] if x >= data[i-1]: index = bisect.bisect_right(data3[low:len(data3) - low-1], x, index, len(data3) - low-1) else: index = bisect.bisect_right(data3[low:index], x, low, index) data3.insert(index, x) """ t2 = Timer(stmt = sample, setup=setup) a = t2.timeit(1) print a t3 = Timer(stmt = new, setup=setup) b = t3.timeit(1) print b print (str((a - b)/b)) ==================================== Nha Pham Mar 07 2015

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Summary of Python tracker Issues
by Python tracker 06 Mar '15

06 Mar '15

ACTIVITY SUMMARY (2015-02-27 - 2015-03-06) 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 4804 (+16) closed 30555 (+45) total 35359 (+61) Open issues with patches: 2260 Issues opened (47) ================== #22079: Ensure in PyType_Ready() that base class of static type is sta http://bugs.python.org/issue22079 reopened by doko #23538: New Windows installer in 3.5.0a1 breaks compatibility with Win http://bugs.python.org/issue23538 opened by Link Mauve #23539: Content-length not set for HTTP methods expecting body when bo http://bugs.python.org/issue23539 opened by demian.brecht #23540: Proposal for asyncio: SubprocessTransport.detach() to detach a http://bugs.python.org/issue23540 opened by martius #23542: Update PEP 476 for using urllib2.build_opener() http://bugs.python.org/issue23542 opened by Shakeel Mohamed #23543: encoding error trying to save string to file http://bugs.python.org/issue23543 opened by Gravitania #23544: IDLE hangs when selecting Stack View with debug active http://bugs.python.org/issue23544 opened by Andrew.Harrington #23545: Turn on extra warnings on GCC http://bugs.python.org/issue23545 opened by serhiy.storchaka #23546: windows, IDLE and pep 397 http://bugs.python.org/issue23546 opened by Liam.Marsh #23549: heapq docs should be more precise about how to access the smal http://bugs.python.org/issue23549 opened by eli.bendersky #23550: Add to unicodedata a function to query the "Quick_Check" prope http://bugs.python.org/issue23550 opened by Hammerite #23551: IDLE to provide menu options for using PIP http://bugs.python.org/issue23551 opened by rhettinger #23552: Have timeit warn about runs that are not independent of each o http://bugs.python.org/issue23552 opened by rhettinger #23553: Reduce the number of comparisons for range checking. http://bugs.python.org/issue23553 opened by rhettinger #23554: EchoServerClientProtocol class should be called EchoServerProt http://bugs.python.org/issue23554 opened by gc #23555: behavioural change in argparse set_defaults in python 2.7.9 http://bugs.python.org/issue23555 opened by doko #23556: Scope for raise without argument is different in Python 2 and http://bugs.python.org/issue23556 opened by a3nm #23557: Misc/SpecialBuilds.txt contains outdated information about PYM http://bugs.python.org/issue23557 opened by Jakub Klama #23560: Group the docs of similar methods in stdtypes.rst http://bugs.python.org/issue23560 opened by ezio.melotti #23564: Patch fixing sanity check for ordered fd sequence in _posixsub http://bugs.python.org/issue23564 opened by Hisham Muhammad #23565: local_clear walks the list of threads without holding head_loc http://bugs.python.org/issue23565 opened by stutzbach #23566: RFE: faulthandler.register() should support file descriptors http://bugs.python.org/issue23566 opened by haypo #23567: os.stat() tuple access vs named attribute access int vs float http://bugs.python.org/issue23567 opened by gregory.p.smith #23568: unittest.mock.MagicMock doesn't support __rdivmod__ http://bugs.python.org/issue23568 opened by zkrynicki #23570: Change "with subprocess.Popen():" (context manager) to ignore http://bugs.python.org/issue23570 opened by haypo #23571: Raise SystemError if a function returns a result with an excep http://bugs.python.org/issue23571 opened by haypo #23572: functools.singledispatch fails when "not BaseClass" is True http://bugs.python.org/issue23572 opened by Sergio Pascual #23573: Avoid redundant allocations in str.find and like http://bugs.python.org/issue23573 opened by serhiy.storchaka #23574: datetime: support leap seconds http://bugs.python.org/issue23574 opened by haypo #23575: MIPS64 needs ffi's n32.S http://bugs.python.org/issue23575 opened by Simon Hoinkis #23577: Add tests for wsgiref.validate http://bugs.python.org/issue23577 opened by ashkop #23578: struct.pack error messages do not indicate which argument was http://bugs.python.org/issue23578 opened by alynn #23579: Amazon.com links http://bugs.python.org/issue23579 opened by Edrie Ddrie #23581: unittest.mock.MagicMock doesn't support matmul (@) operator http://bugs.python.org/issue23581 opened by zkrynicki #23583: IDLE: printing unicode subclasses broken (again) http://bugs.python.org/issue23583 opened by mjpieters #23584: test_doctest lineendings fails in verbose mode http://bugs.python.org/issue23584 opened by jbeck #23585: patchcheck doesn't depend on all http://bugs.python.org/issue23585 opened by rbcollins #23587: asyncio: use the new traceback.TracebackException class http://bugs.python.org/issue23587 opened by haypo #23588: Errno conflicts in ssl.SSLError http://bugs.python.org/issue23588 opened by Ben.Darnell #23589: Redundant sentence in FAQ http://bugs.python.org/issue23589 opened by fossilet #23591: Add IntFlags http://bugs.python.org/issue23591 opened by serhiy.storchaka #23592: SIGSEGV on interpreter shutdown, with daemon threads running w http://bugs.python.org/issue23592 opened by A. Skrobov #23593: Update Windows and OS X installer OpenSSL to 1.0.2 http://bugs.python.org/issue23593 opened by ned.deily #23595: Split the math module into _math (C) + math (py) http://bugs.python.org/issue23595 opened by haypo #23596: gzip argparse interface http://bugs.python.org/issue23596 opened by Antony.Lee #23597: Allow easy display of local variables in log messages? http://bugs.python.org/issue23597 opened by ncoghlan #23598: No backspace on curses on iTerm (mac) http://bugs.python.org/issue23598 opened by ragreener Most recent 15 issues with no replies (15) ========================================== #23598: No backspace on curses on iTerm (mac) http://bugs.python.org/issue23598 #23591: Add IntFlags http://bugs.python.org/issue23591 #23588: Errno conflicts in ssl.SSLError http://bugs.python.org/issue23588 #23585: patchcheck doesn't depend on all http://bugs.python.org/issue23585 #23584: test_doctest lineendings fails in verbose mode http://bugs.python.org/issue23584 #23581: unittest.mock.MagicMock doesn't support matmul (@) operator http://bugs.python.org/issue23581 #23578: struct.pack error messages do not indicate which argument was http://bugs.python.org/issue23578 #23577: Add tests for wsgiref.validate http://bugs.python.org/issue23577 #23575: MIPS64 needs ffi's n32.S http://bugs.python.org/issue23575 #23573: Avoid redundant allocations in str.find and like http://bugs.python.org/issue23573 #23572: functools.singledispatch fails when "not BaseClass" is True http://bugs.python.org/issue23572 #23568: unittest.mock.MagicMock doesn't support __rdivmod__ http://bugs.python.org/issue23568 #23565: local_clear walks the list of threads without holding head_loc http://bugs.python.org/issue23565 #23560: Group the docs of similar methods in stdtypes.rst http://bugs.python.org/issue23560 #23557: Misc/SpecialBuilds.txt contains outdated information about PYM http://bugs.python.org/issue23557 Most recent 15 issues waiting for review (15) ============================================= #23598: No backspace on curses on iTerm (mac) http://bugs.python.org/issue23598 #23596: gzip argparse interface http://bugs.python.org/issue23596 #23595: Split the math module into _math (C) + math (py) http://bugs.python.org/issue23595 #23593: Update Windows and OS X installer OpenSSL to 1.0.2 http://bugs.python.org/issue23593 #23591: Add IntFlags http://bugs.python.org/issue23591 #23589: Redundant sentence in FAQ http://bugs.python.org/issue23589 #23585: patchcheck doesn't depend on all http://bugs.python.org/issue23585 #23584: test_doctest lineendings fails in verbose mode http://bugs.python.org/issue23584 #23583: IDLE: printing unicode subclasses broken (again) http://bugs.python.org/issue23583 #23577: Add tests for wsgiref.validate http://bugs.python.org/issue23577 #23575: MIPS64 needs ffi's n32.S http://bugs.python.org/issue23575 #23574: datetime: support leap seconds http://bugs.python.org/issue23574 #23573: Avoid redundant allocations in str.find and like http://bugs.python.org/issue23573 #23571: Raise SystemError if a function returns a result with an excep http://bugs.python.org/issue23571 #23570: Change "with subprocess.Popen():" (context manager) to ignore http://bugs.python.org/issue23570 Top 10 most discussed issues (10) ================================= #23496: Steps for Android Native Build of Python 3.4.2 http://bugs.python.org/issue23496 26 msgs #23539: Content-length not set for HTTP methods expecting body when bo http://bugs.python.org/issue23539 26 msgs #23595: Split the math module into _math (C) + math (py) http://bugs.python.org/issue23595 14 msgs #17911: traceback: add a new thin class storing a traceback without st http://bugs.python.org/issue17911 13 msgs #23553: Reduce the number of comparisons for range checking. http://bugs.python.org/issue23553 12 msgs #23571: Raise SystemError if a function returns a result with an excep http://bugs.python.org/issue23571 12 msgs #22936: traceback module has no way to show locals http://bugs.python.org/issue22936 11 msgs #23512: The list of built-in functions is not alphabetical on https:// http://bugs.python.org/issue23512 10 msgs #23524: Use _set_thread_local_invalid_parameter_handler in posixmodule http://bugs.python.org/issue23524 10 msgs #23505: Urlparse insufficient validation leads to open redirect http://bugs.python.org/issue23505 9 msgs Issues closed (43) ================== #3111: multiprocessing ppc Debian/ ia64 Ubuntu compilation error http://bugs.python.org/issue3111 closed by davin #6461: multiprocessing: freezing apps on Windows http://bugs.python.org/issue6461 closed by davin #11097: MSI: Remove win32com dependency from installer generator http://bugs.python.org/issue11097 closed by steve.dower #13697: python RLock implementation unsafe with signals http://bugs.python.org/issue13697 closed by pitrou #18382: multiprocessing's overlapped PipeConnection issues on Windows http://bugs.python.org/issue18382 closed by steve.dower #19075: Add sorting algorithm visualization to turtledemo http://bugs.python.org/issue19075 closed by ethan.furman #19931: namedtuple docstrings are verbose for no added benefit http://bugs.python.org/issue19931 closed by rhettinger #19980: Improve help('non-topic') response http://bugs.python.org/issue19980 closed by serhiy.storchaka #20147: multiprocessing.Queue.get() raises queue.Empty exception if ev http://bugs.python.org/issue20147 closed by davin #20521: Cleanup for "dis" module documentation http://bugs.python.org/issue20521 closed by berker.peksag #21293: Remove "capsule hack" from object.c? http://bugs.python.org/issue21293 closed by larry #21619: Cleaning up a subprocess with a broken pipe http://bugs.python.org/issue21619 closed by serhiy.storchaka #22791: datetime.utcfromtimestamp() shoud have option for create tz aw http://bugs.python.org/issue22791 closed by belopolsky #22801: collections.Counter, when empty, doesn't raise an error with & http://bugs.python.org/issue22801 closed by rhettinger #22817: re.split fails with lookahead/behind http://bugs.python.org/issue22817 closed by serhiy.storchaka #22840: strpdate('20141110', '%Y%m%d%H%S') returns wrong date http://bugs.python.org/issue22840 closed by belopolsky #23263: Python 3 gives misleading errors when validating unicode ident http://bugs.python.org/issue23263 closed by haypo #23304: Unused Superclass in calendar.py http://bugs.python.org/issue23304 closed by serhiy.storchaka #23362: integer overflow in string translate http://bugs.python.org/issue23362 closed by python-dev #23367: integer overflow in unicodedata.normalize http://bugs.python.org/issue23367 closed by python-dev #23368: integer overflow in _PyUnicode_AsKind http://bugs.python.org/issue23368 closed by serhiy.storchaka #23387: test_urllib2 fails with HTTP Error 502: Bad Gateway http://bugs.python.org/issue23387 closed by berker.peksag #23471: 404 Not Found when downloading Python 3.4.3rc1 Documentation http://bugs.python.org/issue23471 closed by larry #23477: Increase coverage for wsgiref module http://bugs.python.org/issue23477 closed by berker.peksag #23494: adding timedelta to datetime object is not timezone aware http://bugs.python.org/issue23494 closed by belopolsky #23504: Add __all__ into types http://bugs.python.org/issue23504 closed by serhiy.storchaka #23521: OverflowError from timedelta * float in datetime.py http://bugs.python.org/issue23521 closed by belopolsky #23527: test_smtpnet uses incorrect port for STARTTLS http://bugs.python.org/issue23527 closed by berker.peksag #23541: Re module's match() fails to halt on a particular input http://bugs.python.org/issue23541 closed by serhiy.storchaka #23547: Misdirected http://bugs.python.org/issue23547 closed by benjamin.peterson #23548: TypeError in event loop finalizer, new in Python 3.4.3 http://bugs.python.org/issue23548 closed by haypo #23558: Unable to install Python 3.4.3 amd64 on Windows 8.1 http://bugs.python.org/issue23558 closed by steve.dower #23559: [doc] inconsistent range example output http://bugs.python.org/issue23559 closed by georg.brandl #23561: a little typo in dis.rst; need a non-trivial preceding dot http://bugs.python.org/issue23561 closed by python-dev #23562: file.read() followed by file.write() result in incorrect behav http://bugs.python.org/issue23562 closed by r.david.murray #23563: Faster urllib.urlparse utility functions http://bugs.python.org/issue23563 closed by serhiy.storchaka #23569: unittest.mock.MagicMock.__div__ works but __truediv__ doesn' http://bugs.python.org/issue23569 closed by ned.deily #23576: HTTPS reads can block when content length not available and ti http://bugs.python.org/issue23576 closed by pitrou #23580: Amazon.com links http://bugs.python.org/issue23580 closed by ethan.furman #23582: multiprocessing.Queue.get is not getting all the items in the http://bugs.python.org/issue23582 closed by r.david.murray #23586: Add classproperty to the builtin functions http://bugs.python.org/issue23586 closed by rhettinger #23590: Potential leak in PyFloat_AsDouble. Refcount error. http://bugs.python.org/issue23590 closed by python-dev #23594: Wrong variable name in traceback http://bugs.python.org/issue23594 closed by ned.deily

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subprocess, buffered files, pipes and broken pipe errors
by Victor Stinner 06 Mar '15

06 Mar '15

Hi, => I propose to ignore BrokenPipeError on Popen.__exit__(), what do you think? A recent issue fixed subprocess.Popen.__exit__() to read the exit status of the child process, even if stdin.close() raised a BrokenPipeError: http://bugs.python.org/issue21619 When I saw the issue, I was surprised that Popen.__exit__() doesn't ignore BrokenPipeError. Popen.communicate() is designed to handle corner cases and it ignores BrokenPipeError. Popen.__exit__() only returns when the process exited. The method starts by closing all pipes. Usually the child process notices that stdin was closed and exit (programs used as "pipes" like grep, cat, wc, etc.). The problem is that Popen uses a buffered writer for Popen.stdin with a default buffer size of 8 KB. We may buffer some data and so stdin.close() will call stdin.write(). If the child process exited or closed stdin, the pipe is broken, and the write in the parent process (stdin.close() in Popen.__exit__) will raise BrokenPipeError. I propose to ignore BrokenPipeError in Popen.__exit__, as done in communicate(), for convinience: http://bugs.python.org/issue23570 Serhiy wants to keep BrokenPipeError, he wrote that file.close() should not ignore write errors (read the issue for details). I consider that BrokenPipeError on a pipe is different than a write error on a regular file. EPIPE and SIGPIPE are designed to notify that the pipe is closed and that it's now inefficient to continue to write into this pipe. Ignoring BrokenPipeError in Popen.__exit__() respects this constrain because the method closes stdin and only returns when the process exited. So the caller will not write anything into stdin anymore. What do you think? Victor

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PEP 485 review (isclose())
by Guido van Rossum 05 Mar '15

05 Mar '15

I think it's time to accept PEP 485. I've re-read it once more, and it looks like the text is in great shape. (My only recommendation would be to update the Abstract to state that we're specifically adding math.isclose().) A wording question: "This implementation has a flag that lets the user select which relative tolerance test to apply -- this PEP does not suggest that that be retained, but rather than the weak test be selected." -- I think this was meant to say "... rather *that* the weak test be selected", right? (It would be nice if the sample implementation defaulted to the choice in the PEP.) However, those are just minor edits, and I hereby approve the PEP. Thanks Chris and everyone else for the fruitful discussion (and thanks especially to Chris for eventually ending the bikeshedding and writing a PEP that explains each of the choices). Congrats! -- --Guido van Rossum (python.org/~guido)

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Make review
by Serhiy Storchaka 05 Mar '15

05 Mar '15

If you have ready patches that wait for review and committing, tell me. Send me no more than 5 links to issues per person (for first time) in private and I'll try to make reviews if I'm acquainted with affected modules or areas.

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Re: [Python-Dev] Python-Dev Digest, Vol 140, Issue 6
by SHAHRUKH KHAN 05 Mar '15

05 Mar '15

i think it's time to rename math module to math.py module On Thu, Mar 5, 2015 at 4:30 PM, <python-dev-request(a)python.org> wrote: > Send Python-Dev mailing list submissions to > python-dev(a)python.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://mail.python.org/mailman/listinfo/python-dev > or, via email, send a message with subject or body 'help' to > python-dev-request(a)python.org > > You can reach the person managing the list at > python-dev-owner(a)python.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Python-Dev digest..." > > > Today's Topics: > > 1. Re: PEP 485 review (isclose()) (Chris Barker) > 2. Re: PEP 485 review (isclose()) (Guido van Rossum) > 3. Re: PEP 485 review (isclose()) (Brett Cannon) > 4. Re: PEP 485 review (isclose()) (Guido van Rossum) > 5. Re: PEP 485 review (isclose()) (Chris Barker) > 6. Re: Any volunteers to implement PEP 479? (Guido van Rossum) > 7. Re: Any volunteers to implement PEP 479? (Ethan Furman) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 4 Mar 2015 12:12:34 -0800 > From: Chris Barker <chris.barker(a)noaa.gov> > To: Ethan Furman <ethan(a)stoneleaf.us> > Cc: Python Dev <python-dev(a)python.org> > Subject: Re: [Python-Dev] PEP 485 review (isclose()) > Message-ID: > <CALGmxEKSz6wBzq7NyfN9B0S5EBdg3Y9wJttBoBpoebu= > 8i3jFA(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > On Tue, Mar 3, 2015 at 8:43 AM, Ethan Furman <ethan(a)stoneleaf.us> wrote: > > > On 03/03/2015 01:17 AM, Victor Stinner wrote: > > > > > > > Maybe it's time to rename the math module to _math and create a > > > math.py module, like _decimal/decimal? math.py should end with "from > > > _math import *". > > > > +1 > > > > What do folks think? If we're going to do this, I'll write isclose() in > python. And I could do the work to split it out, too, I suppose. > > -Chris > > > > > > -- > > Christopher Barker, Ph.D. > Oceanographer > > Emergency Response Division > NOAA/NOS/OR&R (206) 526-6959 voice > 7600 Sand Point Way NE (206) 526-6329 fax > Seattle, WA 98115 (206) 526-6317 main reception > > Chris.Barker(a)noaa.gov >

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Any volunteers to implement PEP 479?
by Guido van Rossum 05 Mar '15

05 Mar '15

There's a proof of concept patch in http://bugs.python.org/issue22906, but it doesn't have the __future__ import and probably gets other details wrong. Reference: PEP 479 -- Change StopIteration handling inside generators <https://www.python.org/dev/peps/pep-0479/> -- --Guido van Rossum (python.org/~guido)

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Wg: Re: [Python-checkins] cpython (3.4): Issue #23446: Use PyMem_New instead of PyMem_Malloc to avoid possible integer
by s.krah 01 Mar '15

01 Mar '15

== == == == == == Weitergeleitete Nachricht == == == == == == Absender : Stefan Krah<stefan(a)bytereef.org> Empfänger : "Victor Stinner"<victor.stinner(a)gmail.com> Datum : So, 01 Mrz 2015 18:58:43 +0000 Betreff : Re: [Python-Dev] [Python-checkins] cpython (3.4): Issue #23446: Use PyMem_New instead of PyMem_Malloc to avoid possible integer == == == == == == Weitergeleitete Nachricht == == == == == == On Mon, Feb 16, 2015 at 10:14:59PM +0100, Victor Stinner wrote: > 2015-02-16 17:34 GMT+01:00 Stefan Krah <stefan(a)bytereef.org>: > > > > On Mon, Feb 16, 2015 at 11:35:52AM +0000, serhiy.storchaka wrote: > >> diff --git a/Modules/_testbuffer.c b/Modules/_testbuffer.c > >> --- a/Modules/_testbuffer.c > >> +++ b/Modules/_testbuffer.c > >> @@ -850,7 +850,7 @@ > >> Py_ssize_t *dest; > >> Py_ssize_t x, i; > >> > >> - dest = PyMem_Malloc(len * (sizeof *dest)); > >> + dest = PyMem_New(Py_ssize_t, len); > >> if (dest == NULL) { > >> PyErr_NoMemory(); > >> return NULL; > > > > This, too, was already protected by len == ndim <= 64. > > I don't understand why you don't want to use PyMem_New() even if it > cannot overflow. PyMem_New() is more readable no? It's readable, but I don't see a reason to change code that already has an overflow analysis, especially in 3.4. As I wrote in http://bugs.python.org/issue23446#msg235770 , people need to see that one *can* make certain assumptions about PEP-3118 buffers (otherwise one would go insane with overflow checks when doing arithmetic on the buffers. So, in a sense, this commit removes information for the reader. I would prefer an "assert(len <= 64)" for documentation purposes while keeping the multiplication. Stefan Krah

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