Python-Dev July 2020

python-dev@python.org

118 participants
66 discussions

by Xin, Peixing

Hi, I have several PRs pending there to get review for months. Anyone can help to review and do a merge? Thanks. https://github.com/python/cpython/pull/19447 https://github.com/python/cpython/pull/20254 https://github.com/python/cpython/pull/20256 https://github.com/python/cpython/pull/12670 bpo: https://bugs.python.org/issue31904 Thanks, Peixing

7 months, 1 week

PEP 622: Structural Pattern Matching -- followup

by Guido van Rossum

Everyone, If you've commented and you're worried you haven't been heard, please add your issue *concisely* to this new thread. Note that the following issues are already open and will be responded to separately; please don't bother commenting on these until we've done so: - Alternative spellings for '|' - Whether to add an 'else' clause (and how to indent it) - A different token for wildcards instead of '_' - What to do about the footgun of 'case foo' vs. 'case .foo' (Note that the last two could be combined, e.g. '?foo' or 'foo?' to mark a variable binding and '?' for a wildcard.) -- --Guido van Rossum (python.org/~guido) *Pronouns: he/him **(why is my pronoun here?)* <http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-…>

7 months, 1 week

Memory address vs serial number in reprs

by Serhiy Storchaka

I have problem with the location of hexadecimal memory address in custom reprs. <threading.BoundedSemaphore: 2/3 at 0x7ff4c26b3eb0> vs <threading.BoundedSemaphore at 0x7ff4c26b3eb0: 2/3> The long hexadecimal number makes the repr longer and distracts attention from other useful information. We could get rid of it, but it is useful if we want to distinguish objects of the same type. Although it is hard to distinguish long hexadecimal numbers which differ only by few digits in the middle. What if use serial numbers to differentiate instances? <threading.BoundedSemaphore #5: 2/3> where the serial number starts with 1 and increased for every new instance of that type. The advantages are: * Shorter repr. * Easier to distinguish different objects. * The serial number is unique for the life of program and cannot be reused (in contrary to id/memory address). The disadvantages are: * Increased object size and creation time. I do not propose to use serial numbers for all objects, because it would increase the size of objects and the fixed-size integer can be overflowed for some short-living objects created in mass (like numbers, strings, tuples). But only for some custom objects implemented in Python, for which size and creation time are not critical. I want to start with synchronization objects in threading and multiprocessing which did not have custom reprs, than change reprs of locks and asyncio objects. Is it worth to do?

7 months, 1 week

Re: Python-Dev Digest, Vol 204, Issue 129

by Eric Nieuwland

> On 25 Jul 2020, at 03:44, Rob Cliffe <rob.cliffe(a)btinternet.com> wrote: > > Without arguing for or against allowing a capture variable, IMO rather > than syntax like > match <expr> into <var>: > it would be far better (and not require a new keyword) to write this as > with <var> as match <expr>: > > On 24/06/2020 20:38, Guido van Rossum wrote: >> Everyone, >> >> If you've commented and you're worried you haven't been heard, please=20 >> add your issue *concisely* to this new thread. Note that the following=20 >> issues are already open and will be responded to separately; please=20 >> don't bother commenting on these until we've done so: >> >> - Alternative spellings for '|' >> - Whether to add an 'else' clause (and how to indent it) >> - A different token for wildcards instead of '_' >> - What to do about the footgun of 'case foo' vs. 'case .foo' >> >> (Note that the last two could be combined, e.g. '?foo' or 'foo?' to=20 >> mark a variable binding and '?' for a wildcard.) >> We already have 'with' for contexts. We already have patterns with 'as': - except expression "as" identifier ":" - "import" module "as" identifier - "with" expression "as" target So I think this would be quite confusing.

7 months, 1 week

PEP 622: Structural Pattern Matching -- followup

by Eric Nieuwland

7 months, 1 week

Summary of Python tracker Issues

by Python tracker

ACTIVITY SUMMARY (2020-07-17 - 2020-07-24) 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 7569 (+19) closed 45560 (+43) total 53129 (+62) Open issues with patches: 3075 Issues opened (44) ================== #38946: IDLE on macOS 10.15 Catalina does not open double-clicked file https://bugs.python.org/issue38946 reopened by ned.deily #41288: Pickle crashes unpickling invalid NEWOBJ_EX opcode https://bugs.python.org/issue41288 reopened by serhiy.storchaka #41314: PEP 563 and annotations __future__ mandatory version https://bugs.python.org/issue41314 reopened by gvanrossum #41326: Build failure in blurb-it repo: "Failed building wheel for yar https://bugs.python.org/issue41326 opened by Mariatta #41328: Hudson CI is not available anymore https://bugs.python.org/issue41328 opened by DmytroLitvinov #41330: Inefficient error-handle for CJK encodings https://bugs.python.org/issue41330 opened by malin #41332: connect_accepted_socket() missing from AbstractEventLoop https://bugs.python.org/issue41332 opened by alex.gronholm #41335: free(): invalid pointer in list_ass_item() in Python 3.7.3 https://bugs.python.org/issue41335 opened by Howard_Landman #41336: Sporadic segfaults during zoneinfo object creation stopped usi https://bugs.python.org/issue41336 opened by xtreak #41340: Not very good strcpy implementation in cpython/Python/strdup.c https://bugs.python.org/issue41340 opened by fj92f3jj923f923 #41341: Recursive evaluation of ForwardRef (and PEP 563) https://bugs.python.org/issue41341 opened by joperez #41344: SharedMemory crash when size is 0 https://bugs.python.org/issue41344 opened by vinay0410 #41345: Remote end closed connection without response https://bugs.python.org/issue41345 opened by Michal Arbet #41346: test_thousand and compileall hangs on riscv64 https://bugs.python.org/issue41346 opened by felixonmars #41348: Support replacing global function pointers in a shared library https://bugs.python.org/issue41348 opened by Unai Martinez #41349: idle not going full screen when I rotate screen 90° on mac https://bugs.python.org/issue41349 opened by Tim Z #41350: Use of zipfile.Path causes attempt to write after ZipFile is c https://bugs.python.org/issue41350 opened by Nick Henderson #41352: FileIO.readall() should raise "UnsupportedOperation" when in " https://bugs.python.org/issue41352 opened by Ziyi Wang #41353: Indicate supported sound header formats https://bugs.python.org/issue41353 opened by nanjekyejoannah #41354: filecmp.cmp documentation does not match actual code https://bugs.python.org/issue41354 opened by chanke #41355: os.link(..., follow_symlinks=False) without linkat(3) https://bugs.python.org/issue41355 opened by ronaldoussoren #41356: Convert bool.__new__ to argument clinic https://bugs.python.org/issue41356 opened by Dennis Sweeney #41357: pathlib.Path.resolve incorrect os.path equivalent https://bugs.python.org/issue41357 opened by Jendrik Weise #41359: argparse mutually exclusive group does not exclude in some ca https://bugs.python.org/issue41359 opened by kkarbowiak #41360: method _tunnel does not allow for a standard proxy authenticat https://bugs.python.org/issue41360 opened by Namyotkin #41362: Regenerating parser table fails (windows) https://bugs.python.org/issue41362 opened by constantmarks #41365: Python Launcher is sorry to say... No pyvenv.cfg file https://bugs.python.org/issue41365 opened by Packhash #41367: Popen Timeout raised on 3.6 but not on 3.8 https://bugs.python.org/issue41367 opened by Joan Prat Rigol #41368: Allow compiling Python with llvm-clang on Windows. https://bugs.python.org/issue41368 opened by William Pickard #41369: Update to libmpdec-2.5.1 https://bugs.python.org/issue41369 opened by skrah #41370: PEP 585 and ForwardRef https://bugs.python.org/issue41370 opened by joperez #41371: test_zoneinfo fails when lzma module is unavailable https://bugs.python.org/issue41371 opened by doodspav #41372: Log exception never retrieved in concurrent.futures https://bugs.python.org/issue41372 opened by bar.harel #41373: IDLE: edit/save files created by Windows Explorer https://bugs.python.org/issue41373 opened by terry.reedy #41374: socket.TCP_* no longer available with cygwin 3.1.6+ https://bugs.python.org/issue41374 opened by lazka #41376: site.getusersitepackages() incorrectly claims that PYTHONNOUSE https://bugs.python.org/issue41376 opened by pelson #41377: memoryview of str (unicode) https://bugs.python.org/issue41377 opened by jakirkham #41380: Add snake example to turtledemo https://bugs.python.org/issue41380 opened by Ehsonjon Gadoev #41381: Google chat handler in Logging module https://bugs.python.org/issue41381 opened by anandtripathi5 #41383: Provide a limit arguments for __repr__ https://bugs.python.org/issue41383 opened by Bernat Gabor #41384: tkinter raises TypeError when it's supposed to raise TclError https://bugs.python.org/issue41384 opened by Akuli #41385: test_executable_without_cwd fails on appx test run in Azure pi https://bugs.python.org/issue41385 opened by xtreak #41386: Popen.wait does not account for negative return codes https://bugs.python.org/issue41386 opened by MrTroble #41387: Escape needed in the email documentation example https://bugs.python.org/issue41387 opened by Antonio Gutierrez Most recent 15 issues with no replies (15) ========================================== #41387: Escape needed in the email documentation example https://bugs.python.org/issue41387 #41385: test_executable_without_cwd fails on appx test run in Azure pi https://bugs.python.org/issue41385 #41384: tkinter raises TypeError when it's supposed to raise TclError https://bugs.python.org/issue41384 #41376: site.getusersitepackages() incorrectly claims that PYTHONNOUSE https://bugs.python.org/issue41376 #41374: socket.TCP_* no longer available with cygwin 3.1.6+ https://bugs.python.org/issue41374 #41372: Log exception never retrieved in concurrent.futures https://bugs.python.org/issue41372 #41362: Regenerating parser table fails (windows) https://bugs.python.org/issue41362 #41360: method _tunnel does not allow for a standard proxy authenticat https://bugs.python.org/issue41360 #41355: os.link(..., follow_symlinks=False) without linkat(3) https://bugs.python.org/issue41355 #41354: filecmp.cmp documentation does not match actual code https://bugs.python.org/issue41354 #41353: Indicate supported sound header formats https://bugs.python.org/issue41353 #41352: FileIO.readall() should raise "UnsupportedOperation" when in " https://bugs.python.org/issue41352 #41348: Support replacing global function pointers in a shared library https://bugs.python.org/issue41348 #41346: test_thousand and compileall hangs on riscv64 https://bugs.python.org/issue41346 #41344: SharedMemory crash when size is 0 https://bugs.python.org/issue41344 Most recent 15 issues waiting for review (15) ============================================= #41386: Popen.wait does not account for negative return codes https://bugs.python.org/issue41386 #41385: test_executable_without_cwd fails on appx test run in Azure pi https://bugs.python.org/issue41385 #41380: Add snake example to turtledemo https://bugs.python.org/issue41380 #41376: site.getusersitepackages() incorrectly claims that PYTHONNOUSE https://bugs.python.org/issue41376 #41373: IDLE: edit/save files created by Windows Explorer https://bugs.python.org/issue41373 #41369: Update to libmpdec-2.5.1 https://bugs.python.org/issue41369 #41357: pathlib.Path.resolve incorrect os.path equivalent https://bugs.python.org/issue41357 #41356: Convert bool.__new__ to argument clinic https://bugs.python.org/issue41356 #41354: filecmp.cmp documentation does not match actual code https://bugs.python.org/issue41354 #41353: Indicate supported sound header formats https://bugs.python.org/issue41353 #41352: FileIO.readall() should raise "UnsupportedOperation" when in " https://bugs.python.org/issue41352 #41350: Use of zipfile.Path causes attempt to write after ZipFile is c https://bugs.python.org/issue41350 #41344: SharedMemory crash when size is 0 https://bugs.python.org/issue41344 #41341: Recursive evaluation of ForwardRef (and PEP 563) https://bugs.python.org/issue41341 #41340: Not very good strcpy implementation in cpython/Python/strdup.c https://bugs.python.org/issue41340 Top 10 most discussed issues (10) ================================= #41295: CPython 3.8.4 regression on __setattr__ in multiinheritance wi https://bugs.python.org/issue41295 11 msgs #38628: Issue with ctypes in AIX https://bugs.python.org/issue38628 8 msgs #41273: asyncio: proactor read transport: use recv_into instead of rec https://bugs.python.org/issue41273 6 msgs #41365: Python Launcher is sorry to say... No pyvenv.cfg file https://bugs.python.org/issue41365 6 msgs #23882: unittest discovery doesn't detect namespace packages when give https://bugs.python.org/issue23882 5 msgs #41317: sock_accept() does not remove server socket reader on cancella https://bugs.python.org/issue41317 5 msgs #41330: Inefficient error-handle for CJK encodings https://bugs.python.org/issue41330 5 msgs #41350: Use of zipfile.Path causes attempt to write after ZipFile is c https://bugs.python.org/issue41350 5 msgs #41377: memoryview of str (unicode) https://bugs.python.org/issue41377 5 msgs #40979: typing module docs: keep text, add subsections https://bugs.python.org/issue40979 4 msgs Issues closed (42) ================== #4630: IDLE: add cursor noblink option https://bugs.python.org/issue4630 closed by terry.reedy #10879: cgi memory usage https://bugs.python.org/issue10879 closed by inada.naoki #35617: unittest discover does not work with implicit namespaces https://bugs.python.org/issue35617 closed by inada.naoki #36723: Unittest Discovery for namespace subpackages dot notation fail https://bugs.python.org/issue36723 closed by inada.naoki #37703: Inconsistent gather with child exception https://bugs.python.org/issue37703 closed by asvetlov #38018: Increase Code Coverage for multiprocessing.shared_memory https://bugs.python.org/issue38018 closed by vinay0410 #38169: Increase Code Coverage for SharedMemory and ShareableListe https://bugs.python.org/issue38169 closed by corona10 #39073: [security] email module incorrect handling of CR and LF newlin https://bugs.python.org/issue39073 closed by ned.deily #39603: [security] http.client: HTTP Header Injection in the HTTP meth https://bugs.python.org/issue39603 closed by ned.deily #40741: Upgrade to SQLite v3.32 in Windows and macOS builds https://bugs.python.org/issue40741 closed by steve.dower #41220: add optional make_key argument to lru_cache https://bugs.python.org/issue41220 closed by rhettinger #41229: Asynchronous generator memory leak https://bugs.python.org/issue41229 closed by njs #41262: Convert memoryview to Argument Clinic https://bugs.python.org/issue41262 closed by serhiy.storchaka #41271: Add support for io_uring to cpython https://bugs.python.org/issue41271 closed by ronaldoussoren #41272: New clause in FOR and WHILE instead of ELSE https://bugs.python.org/issue41272 closed by rhettinger #41297: Remove doctest import from heapq https://bugs.python.org/issue41297 closed by ronaldoussoren #41300: IDLE: add missing import io in iomenu.py https://bugs.python.org/issue41300 closed by terry.reedy #41311: Add a function to get a random sample from an iterable (reserv https://bugs.python.org/issue41311 closed by rhettinger #41315: Add mathematical functions as wrappers to decimal.Decimal meth https://bugs.python.org/issue41315 closed by terry.reedy #41321: Calculate timestamp is wrong in datetime.datetime https://bugs.python.org/issue41321 closed by SilentGhost #41325: Document addition of `mock.call_args.args` and `mock.call_args https://bugs.python.org/issue41325 closed by xtreak #41327: Windows Store "stub" Python executables give confusing behavio https://bugs.python.org/issue41327 closed by brett.cannon #41329: IDLE not saving .py files https://bugs.python.org/issue41329 closed by terry.reedy #41331: Sphinx can't find asdl.py when not started from the Doc/ direc https://bugs.python.org/issue41331 closed by mdk #41333: Convert OrderedDict.pop() to Argument Clinic https://bugs.python.org/issue41333 closed by serhiy.storchaka #41334: Convert str(), bytes() and bytearray() to Argument Clinic https://bugs.python.org/issue41334 closed by serhiy.storchaka #41337: strangnedd with the parser https://bugs.python.org/issue41337 closed by eric.smith #41338: test_decimal emits DeprecationWarning due to PyUnicode_FromUni https://bugs.python.org/issue41338 closed by inada.naoki #41339: make queue.Queue objects iterable https://bugs.python.org/issue41339 closed by rhettinger #41342: Convert int.__round__ to Argument Clinic https://bugs.python.org/issue41342 closed by serhiy.storchaka #41343: Convert complex methods to Argument Clinic https://bugs.python.org/issue41343 closed by serhiy.storchaka #41347: collections.deque.count performance enhancement https://bugs.python.org/issue41347 closed by corona10 #41351: IDLE does not close the brackets and does not insert the closi https://bugs.python.org/issue41351 closed by terry.reedy #41358: Unable to uninstall Python launcher using command line https://bugs.python.org/issue41358 closed by hap #41361: Converting collections.deque methods to Argument Clinic https://bugs.python.org/issue41361 closed by rhettinger #41363: python 3.8.5 folder not visible in https://www.python.org/ftp/ https://bugs.python.org/issue41363 closed by ned.deily #41364: Optimise uuid platform detection https://bugs.python.org/issue41364 closed by steve.dower #41366: sign-conversion warning in 3.9 beta https://bugs.python.org/issue41366 closed by inada.naoki #41375: `mode` security concern https://bugs.python.org/issue41375 closed by YoSTEALTH #41378: IDLE EOL convention not set on a empty file https://bugs.python.org/issue41378 closed by serhiy.storchaka #41379: Configparser is not reading Indended Sections as Mentioned in https://bugs.python.org/issue41379 closed by SilentGhost #41382: print() unpredictable behaviour https://bugs.python.org/issue41382 closed by n-io

7 months, 1 week

How to customize CPython to a minimal set

by Huang, Yang

Hi, all There is a request to run python in a Linux-based embedded resource constrained system with sqlite3 support. So many features are not required, like posixmodule, signalmodule, hashtable ... But seems there are some dependencies among the Modules/Parser/Python/Objects/Programs... Is there a way to tailor CPython 3 to a minimal set with sqlite3 (the less syscalls the better) ? Is it possible to do that? Thank you.

7 months, 1 week

Add mimetypes.mimesniff

by Dong-hee Na

Hi, A few weeks ago, I suggested adding mimetypes.mimesniff on stdlib. (https://bugs.python.org/issue40841, https://github.com/python/cpython/pull/20720) Detecting MIME types well is an important feature and we already have mimetypes detection library but AFAIK it is not good enough. Note that some of our stdlib module already use the sniffing algorithm (e.g imghdr) The question is how exactly the mime sniffing should be done in terms of file formats and algorithm. Luckily, WHATWG published the standard for mime sniffing, and I think we should follow it. (https://mimesniff.spec.whatwg.org/) So I created the issue on the bpo and implemented it. I 'd like to listen to all your opinions :) -- Software Development Engineer at Kakao corp. Tel: +82 10-3353-9127 Email: donghee.na92(a)gmail.com | denny.i(a)kakaocorp.com Linkedin: https://www.linkedin.com/in/dong-hee-na-2b713b49/

7 months, 1 week

datetime module refactoring: folder vs parallel private modules

by Paul Ganssle

Hi all, I was hoping to get some feedback on a proposed refactoring of the datetime module that should dramatically improve import performance. The datetime module is implemented more or less in full both in pure Python and in C; the way that this is currently achieved <https://github.com/python/cpython/blob/5a2bac7fe0e7a2b67fd57c7a9176a50feed0…> is that the pure Python implementation is defined in datetime.py, and the C implementation is in _datetime, and /after/ the full Python version is defined, the C version is star-imported and thus any symbols defined in both versions are taken from the C version; if the C version is used, any private symbols used only in the pure Python implementation are manually deleted (see the end of the file <https://github.com/python/cpython/blob/5a2bac7fe0e7a2b67fd57c7a9176a50feed0…>). This adds a lot of unnecessary overhead, both to define a bunch of unused classes and functions and to import modules that are required for the pure Python implementation but not for the C implementation. In the issue he created about this <https://bugs.python.org/issue40799>, Victor Stinner demonstrated that moving the pure Python implementation to its own module would speed up the import of datetime by a factor of 4. I think that we should indeed move the pure Python implementation into its own module, despite the fact that this is almost guaranteed to break some people either relying on implementation details or doing something funky with the import system — I don't think it should break anyone relying on the guaranteed public interface. The issue at hand is that we have two options available for the refactoring: either move the pure Python implementation to its own private top-level module (single file) such as `_pydatetime`, or make `datetime` a folder with an `__init__.py` and move the pure Python implementation to `datetime._pydatetime` or something of that nature. The decimal and zoneinfo modules both have this same issue; the decimal module uses the first strategy with _pydecimal and decimal, the zoneinfo module uses a folder with a zoneinfo._zoneinfo submodule. Assuming we go forward with this, we need to decide which strategy to adopt for datetime. In favor of using a datetime/ folder, I'd say it's cleaner to put the pure Python implementation of datetime under the datetime namespace, and also it gives us more freedom to play with the module's structure in the future, since we could have lazily-imported sub-components, or we could implement some logic common to both implementations in Python and import it from a `datetime._common` module without requiring the C version to import the entire Python version, similar to the way zoneinfo has the zoneinfo._common <https://github.com/python/cpython/blob/master/Lib/zoneinfo/_common.py> module. The downside of the folder method is that it complicates the way datetime is imported — /especially/ if we add additional structure to the module, or add any logic into the __init__.py. Two single-file modules side-by-side, one imported by the other doesn't change anything about the nature of how the datetime module is imported, and is much less likely to break anything. Anyone have thoughts or strong preferences here? Anyone have use cases where one or the other approaches is likely to cause a bunch of undue hardship? I'd like to avoid moving this more than once. Best, Paul P.S. Victor's PR moving this code to _pydatetime <https://github.com/python/cpython/pull/20472> is currently done in such a way that the ability to backport changes from post-refactoring to pre-refactoring branches is preserved; I have not checked but I /think/ we should be able to do the same thing with the other strategy as well.

7 months, 2 weeks

Official joint communication from the Python Steering Council, PSF Board of Directors, and PSF Conduct WG

by Python Steering Council

Recently, a series of discussions on this mailing list resulted in behavior that did not live up to the standards of the Python Community. The PSF Board of Directors, Python Steering Council, and the PSF Conduct Working Group would like to remind this community that our shared goal is to advance the Python language while simultaneously building a diverse, inclusive, and welcoming Python community. While the community has made progress in recent years, this discussion made it clear to many of us that we still have room to grow. At the request of the PSF Board, the Steering Council, and members of the community, the PSF Conduct WG met to discuss these recent events and recommend action. As a result, warnings will be given to several members of the Python Community, and the Steering Council will be taking further action. Especially during passionate discussions like these, we'd like to ask that all Pythonistas focus on being welcoming and respectful, and that we all try to act in the best spirit of the Python Community. Thank you, Python Steering Council PSF Board of Directors PSF Conduct WG

7 months, 2 weeks

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Python-Dev July 2020