Mailman 3 February 2019 - Python-Dev

Python 3.8 alpha and AIX buildbot “support” moving forward.
by Michael Felt (aixtools) 09 Feb '19

09 Feb '19

Congratulations on the official begin of the alpha phase of Python3-3.8. I hope there will be time to consider three of my PRs so that this phase has at least one of the AIX buildbots (not mine I fear) is passing all the tests and can finally serve it’s real purpose and signal when a change toggles it’s status from PASS to FAIL. Next week I hope to have some time to dig deeper and try to establish why my bot fails additional tests (in the multiprocessing module(s)) as well why AIX fails test_bdb when utf8 support is (additionally) installed but passes when utf8 support is not installed. While I am also concerned about AIX status I also hope that my inspection is helping to improve Python. Sincerely, Michael Sent from my iPhone

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About the future of multi-process Python
by Antoine Pitrou 08 Feb '19

08 Feb '19

Hello, For the record there are number of initiatives currently to boost the usefulness and efficiency of multi-process computation in Python. One of them is PEP 574 (zero-copy pickling with out-of-band buffers), which I'm working on. Another is Pierre Glaser's work on allowing pickling of dynamic functions and classes with the C-accelerated _pickle module (rather than the slow pure Python implementation): https://bugs.python.org/issue35900 https://bugs.python.org/issue35911 Another is Davin's work on shared memory managers. There are also emerging standards like Apache Arrow that provide a shared, runtime-agnostic, compute-friendly representation for in-memory tabular data, and third-party frameworks like Dask which are potentially able to work on top of that and expose nice end-user APIs. For maximum synergy between these initiatives and the resulting APIs, it is better if things are done in the open ;-) Regards Antoine.

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[RELEASE] Python 3.8.0a1 is now available for testing
by Łukasz Langa 08 Feb '19

08 Feb '19

I packaged my first release. *wipes sweat off of face* Go get it here: https://www.python.org/downloads/release/python-380a1/ Python 3.8.0a1 is the first of four planned alpha releases of Python 3.8, the next feature release of Python. During the alpha phase, Python 3.8 remains under heavy development: additional features will be added and existing features may be modified or deleted. Please keep in mind that this is a preview release and its use is not recommended for production environments. The next preview release, 3.8.0a2, is planned for 2019-02-24. Apart from building the Mac installers, Ned helped me a lot with the process, thank you! Ernest was super quick providing me with all required access and fixing a Unicode problem I found in Salt, thank you! Finally, this release was made on a train to Düsseldorf. There's a PyPy sprint there. The train is pretty cool, makes this "Wasm! Wasm!" sound. - Ł

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CPython on Windows ARM32
by Paul Monson 08 Feb '19

08 Feb '19

Hi Python Developers, I'm Paul Monson, I've spent about 20 years working with embedded software. Since 2010 I've worked for Microsoft as a developer. Our team is working with CPython on Azure IoT Edge devices that run on x64-based devices. We would like to extend that support to Windows running on ARM 32-bit devices and have a working proof-of-concept. Our team is prepared to provide support for CPython for Windows on ARM32 for 10 years, and to provide build bots for ARM32. I like to propose that the initial sequence of PRs could be: - Update to OpenSSL 1.1.1 (without anything ARM specific) - ready to go - Migrate to libffi directly (finish https://github.com/python/cpython/pull/3806<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.co…>) - Build file updates for OpenSSL ARM and check into cpython-bin-deps - Build file updates for CPython ARM - ctypes updates for ARM - Test module skips for ARM - Library updates and related test fixes for ARM Updating OpenSSL and libffi are independent of ARM support but need to be done as prerequisites. OpenSSL 1.1.0 doesn't have support for ARM32 on Windows but OpenSSL 1.1.1 does. I have OpenSSL 1.1.1a ready to check in to master with all tests passing on x86 and x64 on Windows. Since work has already been done on this for other platforms only very small changes were needed for Windows. I have also integrated and tested the current libffi on Windows x64. Some additonal porting of x86 assembler to MSVC tools will need to be done. I have a working port of ARM32 assembler for MSVC but it may need to be brought up to date and cleaned up. The last four all need to go in together, but can be reviewed separately. We are not planning to support Tk/Tcl on ARM32 because Windows IoT Core, Windows containers don't support GDI, which is a depenency of Tk/Tcl. Since Window IoT Core and Windows container don't support the .msi or .exe installers found on python.org my team at Microsoft will build the CPython for Windows ARM32 from the official repo and distribute it. Thanks in advance, Paul

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bpo-32972: Add unittest.AsyncioTestCase review (for 3.8?)
by David Shawley 05 Feb '19

05 Feb '19

Hi everyone, I added a PR to add a sub-class of unittest.TestCase that makes it possible to write async test methods. I wrote this a few months ago and it is waiting on core review. Is there a core dev that can take up this review? I would love to have this functionality in the core. Lukasz - should we add this to Python 3.8 or is it too late for feature additions? BPO link: https://bugs.python.org/issue32972 <https://bugs.python.org/issue32972> Github PR: https://github.com/python/cpython/pull/10296 <https://github.com/python/cpython/pull/10296> cheers, dave. -- "State and behavior. State and behavior. If it doesn’t bundle state and behavior in a sensible way, it should not be an object, and there should not be a class that produces it." eevee

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Return type of datetime subclasses added to timedelta
by Paul Ganssle 04 Feb '19

04 Feb '19

Happy New Year everyone! I would like to start a thread here for wider feedback on my proposal to change the return type of the addition operation between a datetime subclass and a timedelta. Currently, adding a timedelta to a subclass of datetime /always/ returns a datetime rather than an instance of the datetime subclass. I have an open PR implementing this, PR #10902 <https://github.com/python/cpython/pull/10902>, but I know it's a major change so I did not want to move forward without more discussion. I first brought this up on datetime-SIG <https://mail.python.org/archives/list/datetime-sig@python.org/thread/TGB3VZ…> [1], and we decided to move the discussion over here because the people most likely to object to the change would be on this list and not on datetime-SIG. In addition to the datetime-SIG thread, you may find a detailed rationale for the change in bpo-35364 <https://bugs.python.org/issue35364#msg331065> [2], and a rationale for why we would want to (and arguably already /do/) support subclassing datetime in bpo-32417 <https://bugs.python.org/issue32417#msg331353> [3]. A short version of the strongest rationale for changing how this works is that it is causing inconsistencies in how subclassing is handled in alternate constructors of datetime. For a given subclass of datetime (which I will call DateTimeSub), nearly all alternate constructors already support subclasses correctly - DateTimeSub.fromtimestamp(x) will return a DateTimeSub, for example. However, because DateTimeSub + timedelta returns datetime, any alternate constructor implemented in terms of timedelta additions will leak that implementation detail by returning a datetime object instead of the subclass. The biggest problem is that datetime.fromutc is defined in terms of timedelta addition, so DateTimeSub.now() returns a DateTimeSub object, but DateTimeSub.now(timezone.utc) returns a datetime object! This is one of the most annoying things to work around when building a datetime subclass, and I don't know of any situation where someone /wants/ their subclass to be lost on addition with a timedelta. From my understanding, this has been discussed before and the original objection was that this implementation assumes that the datetime subclass has a constructor with the same (or a sufficiently similar) signature as datetime. This may be a legitimate gripe, but unfortunately that ship has sailed long ago. All of datetime's alternate constructors make this assumption. Any subclass that does not meet this requirement must have worked around it long ago (or they don't care about alternate constructors). Thanks for your attention, I look forward to your replies. Best, Paul [1] https://mail.python.org/archives/list/datetime-sig@python.org/thread/TGB3VZ… [2] https://bugs.python.org/issue35364#msg331065 [3] https://bugs.python.org/issue32417#msg331353

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About multiprocessing maintainership
by Antoine Pitrou 04 Feb '19

04 Feb '19

Hello, In a recent message, Raymond dramatically pretends that I would have "edited out" Davin of the maintainers list for the multiprocessing module. What I did (*) is different: I asked to mark Davin inactive and to stop auto-assigning him on bug tracker issues. Davin was /still/ listed in the experts list, along with me and others. IOW, there was no "editing out". (*) https://github.com/python/devguide/pull/435 The reason I did this is simple: Davin does not do, and has almost never done, any actual maintenance work on multiprocessing (if you are not convinced, just go through the git history, and the PRs that were merged in the ~4 last years). He usually does not respond to tracker issues opened by users. He does not review PRs. The only sizable piece of work he committed is, as I mentioned in the previous thread, still untested and undocumented. Auto-assigning someone who never (AFAICT) responds to issues ultimately does a disservice to users, whose complaints go unanswered; while other people, who /do/ respond to users, are not aware of those stale issues. Regards Antoine.

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Why a merge for 3.8.0a1?
by Stephane Wirtel 04 Feb '19

04 Feb '19

Hi all, After a git pull, I have seen there is a merge for v3.8.0a1 by Łukasz Langa, why? I think the code should keep a linear commit and in this case, it's against the "commit&squash" of CPython and Github :/ Thank you for your response. Stéphane -- Stéphane Wirtel - https://wirtel.be - @matrixise

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Difference between Include/internal and Include/cpython ?
by Antoine Pitrou 03 Feb '19

03 Feb '19

Hello, Can someone explain why we have two separate directories Include/internal and Include/cpython? What is the rule for declaring an API inside one or another? At first sight, it seems to me we're having gratuitous complication here. For example, I notice that PyFloat_Fini() is declared in Include/cpython/pylifecycle.h but PyLong_Fini() is declared in Include/internal/pycore_pylifecycle.h? (and why the additional "pycore_XXX.h" naming convention for some of those files?) Regards Antoine.

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Summary of Python tracker Issues
by Python tracker 01 Feb '19

01 Feb '19

ACTIVITY SUMMARY (2019-01-25 - 2019-02-01) Python tracker at https://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 6985 (+32) closed 40649 (+23) total 47634 (+55) Open issues with patches: 2775 Issues opened (45) ================== #25592: distutils docs: data_files always uses sys.prefix https://bugs.python.org/issue25592 reopened by pitrou #30670: pprint for dict in sorted order or insert order? https://bugs.python.org/issue30670 reopened by josephsmeng #35829: datetime: parse "Z" timezone suffix in fromisoformat() https://bugs.python.org/issue35829 opened by rdb #35830: building multiple (binary) packages from a single project https://bugs.python.org/issue35830 opened by stefan #35832: Installation error https://bugs.python.org/issue35832 opened by Stefano Bonalumi #35833: IDLE: revise doc for control chars sent to Shell https://bugs.python.org/issue35833 opened by Dude Roast #35834: get_type_hints exposes an instance of ForwardRef (internal cla https://bugs.python.org/issue35834 opened by Lincoln Quirk #35838: ConfigParser calls optionxform twice when assigning dict https://bugs.python.org/issue35838 opened by Phil Kang #35839: Suggestion: Ignore sys.modules entries with no __spec__ attrib https://bugs.python.org/issue35839 opened by ncoghlan #35840: Control flow inconsistency on closed asyncio stream https://bugs.python.org/issue35840 opened by schlamar #35841: Datetime strftime() does not return correct week numbers for 2 https://bugs.python.org/issue35841 opened by tr12 #35843: importlib.util docs for namespace packages innaccurate https://bugs.python.org/issue35843 opened by Anthony Sottile #35844: Calling `Multiprocessing.Queue.close()` too quickly causes int https://bugs.python.org/issue35844 opened by charmonium #35845: Can't read a F-contiguous memoryview in physical order https://bugs.python.org/issue35845 opened by pitrou #35846: Incomplete documentation for re.sub https://bugs.python.org/issue35846 opened by pbugnion #35847: RISC-V needs CTYPES_PASS_BY_REF_HACK https://bugs.python.org/issue35847 opened by schwab #35848: readinto is not a method on io.TextIOBase https://bugs.python.org/issue35848 opened by steverpalmer #35849: Added thousands separators to Lib/pstats.py final report https://bugs.python.org/issue35849 opened by addons_zz #35851: Make search result in online docs keep their position when sea https://bugs.python.org/issue35851 opened by roelschroeven #35852: Fixed tests regenerating using CRLF when running it on Windows https://bugs.python.org/issue35852 opened by addons_zz #35854: EnvBuilder and venv symlinks do not work on Windows on 3.7.2 https://bugs.python.org/issue35854 opened by steve.dower #35855: IDLE squeezer: improve unsqueezing and autosqueeze default https://bugs.python.org/issue35855 opened by terry.reedy #35856: bundled pip syntaxwarning https://bugs.python.org/issue35856 opened by Dima.Tisnek #35857: Stacktrace shows lines from updated file on disk, not code act https://bugs.python.org/issue35857 opened by Steve Pryde #35859: Capture behavior depends on the order of an alternation https://bugs.python.org/issue35859 opened by davisjam #35860: ProcessPoolExecutor subprocesses crash & break pool when raisi https://bugs.python.org/issue35860 opened by underyx #35861: test_named_expressions raises SyntaxWarning https://bugs.python.org/issue35861 opened by xtreak #35862: Change the environment for a new process https://bugs.python.org/issue35862 opened by r-or #35866: concurrent.futures deadlock https://bugs.python.org/issue35866 opened by jwilk #35867: NameError is not caught at Task execution https://bugs.python.org/issue35867 opened by Sampsa Riikonen #35868: Support ALL_PROXY environment variable in urllib https://bugs.python.org/issue35868 opened by Oleh Khoma #35869: io.BufferReader.read() returns None https://bugs.python.org/issue35869 opened by steverpalmer #35870: readline() specification is unclear https://bugs.python.org/issue35870 opened by porton #35871: Pdb NameError in generator param and list comprehension https://bugs.python.org/issue35871 opened by jayanth #35872: Creating venv from venv no longer works in 3.7.2 https://bugs.python.org/issue35872 opened by schlamar #35873: Controlling venv from venv no longer works in 3.7.2 https://bugs.python.org/issue35873 opened by schlamar #35874: Clarify that the (...) convertor to PyArg_ParseTuple... accept https://bugs.python.org/issue35874 opened by Antony.Lee #35875: Crash - algos.cp36-win_amd64.pyd join.cp36-win_amd64.pyd https://bugs.python.org/issue35875 opened by AxelArnoldBangert #35876: test_start_new_session for posix_spawnp fails https://bugs.python.org/issue35876 opened by pablogsal #35877: parenthesis is mandatory for named expressions in while statem https://bugs.python.org/issue35877 opened by xtreak #35878: ast.c: end_col_offset may be used uninitialized in this functi https://bugs.python.org/issue35878 opened by vstinner #35879: test_type_comments leaks references https://bugs.python.org/issue35879 opened by vstinner #35880: math.sin has no backward error; this isn't documented https://bugs.python.org/issue35880 opened by jneb #35882: distutils fails with UnicodeEncodeError with strange filename https://bugs.python.org/issue35882 opened by scjody #35883: Change invalid unicode characters to replacement characters in https://bugs.python.org/issue35883 opened by Neui Most recent 15 issues with no replies (15) ========================================== #35882: distutils fails with UnicodeEncodeError with strange filename https://bugs.python.org/issue35882 #35878: ast.c: end_col_offset may be used uninitialized in this functi https://bugs.python.org/issue35878 #35874: Clarify that the (...) convertor to PyArg_ParseTuple... accept https://bugs.python.org/issue35874 #35873: Controlling venv from venv no longer works in 3.7.2 https://bugs.python.org/issue35873 #35867: NameError is not caught at Task execution https://bugs.python.org/issue35867 #35860: ProcessPoolExecutor subprocesses crash & break pool when raisi https://bugs.python.org/issue35860 #35852: Fixed tests regenerating using CRLF when running it on Windows https://bugs.python.org/issue35852 #35844: Calling `Multiprocessing.Queue.close()` too quickly causes int https://bugs.python.org/issue35844 #35827: C API dictionary views type checkers are not documented https://bugs.python.org/issue35827 #35813: shared memory construct to avoid need for serialization betwee https://bugs.python.org/issue35813 #35812: Don't log an exception from the main coroutine in asyncio.run( https://bugs.python.org/issue35812 #35807: Update bundled pip to 19.0 https://bugs.python.org/issue35807 #35803: Test and document that `dir=...` in tempfile may be PathLike https://bugs.python.org/issue35803 #35801: venv in 3.7 references python3 executable https://bugs.python.org/issue35801 #35792: Specifying AbstractEventLoop.run_in_executor as a coroutine co https://bugs.python.org/issue35792 Most recent 15 issues waiting for review (15) ============================================= #35877: parenthesis is mandatory for named expressions in while statem https://bugs.python.org/issue35877 #35876: test_start_new_session for posix_spawnp fails https://bugs.python.org/issue35876 #35862: Change the environment for a new process https://bugs.python.org/issue35862 #35861: test_named_expressions raises SyntaxWarning https://bugs.python.org/issue35861 #35854: EnvBuilder and venv symlinks do not work on Windows on 3.7.2 https://bugs.python.org/issue35854 #35852: Fixed tests regenerating using CRLF when running it on Windows https://bugs.python.org/issue35852 #35849: Added thousands separators to Lib/pstats.py final report https://bugs.python.org/issue35849 #35847: RISC-V needs CTYPES_PASS_BY_REF_HACK https://bugs.python.org/issue35847 #35843: importlib.util docs for namespace packages innaccurate https://bugs.python.org/issue35843 #35826: Typo in example for async with statement with condition https://bugs.python.org/issue35826 #35824: http.cookies._CookiePattern modifying regular expressions https://bugs.python.org/issue35824 #35823: Use vfork() in subprocess on Linux https://bugs.python.org/issue35823 #35813: shared memory construct to avoid need for serialization betwee https://bugs.python.org/issue35813 #35810: Object Initialization Bug with Heap-allocated Types https://bugs.python.org/issue35810 #35803: Test and document that `dir=...` in tempfile may be PathLike https://bugs.python.org/issue35803 Top 10 most discussed issues (10) ================================= #35431: Add a function for computing binomial coefficients to the math https://bugs.python.org/issue35431 12 msgs #25592: distutils docs: data_files always uses sys.prefix https://bugs.python.org/issue25592 10 msgs #35857: Stacktrace shows lines from updated file on disk, not code act https://bugs.python.org/issue35857 10 msgs #35854: EnvBuilder and venv symlinks do not work on Windows on 3.7.2 https://bugs.python.org/issue35854 7 msgs #35848: readinto is not a method on io.TextIOBase https://bugs.python.org/issue35848 6 msgs #35859: Capture behavior depends on the order of an alternation https://bugs.python.org/issue35859 6 msgs #35823: Use vfork() in subprocess on Linux https://bugs.python.org/issue35823 5 msgs #35829: datetime: parse "Z" timezone suffix in fromisoformat() https://bugs.python.org/issue35829 5 msgs #30670: pprint for dict in sorted order or insert order? https://bugs.python.org/issue30670 4 msgs #32834: test_gdb fails with Posix locale in 3.7 https://bugs.python.org/issue32834 4 msgs Issues closed (22) ================== #2212: Cookie.BaseCookie has ambiguous unicode handling https://bugs.python.org/issue2212 closed by martin.panter #29235: Allow profile/cProfile to be used as context managers https://bugs.python.org/issue29235 closed by cheryl.sabella #34003: csv.DictReader can return basic dict instead of OrderedDict https://bugs.python.org/issue34003 closed by rhettinger #35196: IDLE text squeezer is too aggressive and is slow https://bugs.python.org/issue35196 closed by terry.reedy #35717: enum.Enum error on sys._getframe(2) https://bugs.python.org/issue35717 closed by vstinner #35769: IDLE: change new file name from ''Untitled" to "untitled" https://bugs.python.org/issue35769 closed by cheryl.sabella #35780: Recheck logic in the C version of the lru_cache() https://bugs.python.org/issue35780 closed by rhettinger #35797: concurrent.futures.ProcessPoolExecutor does not work in venv o https://bugs.python.org/issue35797 closed by steve.dower #35811: py.exe should unset the __PYVENV_LAUNCHER__ environment variab https://bugs.python.org/issue35811 closed by steve.dower #35825: Py_UNICODE_SIZE=4 fails to link on Windows https://bugs.python.org/issue35825 closed by inada.naoki #35831: Format Spec example says limited to 3.1+ but works in 2.7 https://bugs.python.org/issue35831 closed by fdrake #35835: There is no mention of breakpoint() in the pdb documentation https://bugs.python.org/issue35835 closed by Mariatta #35836: ZeroDivisionError class should have a __name__ attr https://bugs.python.org/issue35836 closed by steven.daprano #35837: smtpd PureProxy breaks on mail_options keyword argument https://bugs.python.org/issue35837 closed by r.david.murray #35842: A potential bug about use of uninitialised variable https://bugs.python.org/issue35842 closed by josh.r #35850: CKAN installation went on script error https://bugs.python.org/issue35850 closed by christian.heimes #35853: Extend the functools module with more higher order function co https://bugs.python.org/issue35853 closed by rhettinger #35858: Consider adding the option of running shell/console commands i https://bugs.python.org/issue35858 closed by jcrmatos #35863: email.headers wraps headers badly https://bugs.python.org/issue35863 closed by r.david.murray #35864: Replace OrderedDict with regular dict in namedtuple's _asdict( https://bugs.python.org/issue35864 closed by rhettinger #35865: configparser document refers about random dict order https://bugs.python.org/issue35865 closed by inada.naoki #35881: test_type_comments leaks references and memory blocks https://bugs.python.org/issue35881 closed by vstinner

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