Mailman 3 October 2019 - Python-Dev

EnHackathon 2019 - seeking core dev support
by Lewis Gaul Nov. 2, 2019

Nov. 2, 2019

Hi all, In early November this year I'll be leading the first ever Python 'EnHackathon' at the Ensoft Cisco office - we anticipate having ~10 first-time contributors, all with experience writing C and/or Python (and training in both). We each have up to 5 days (per year) to contribute, with my intention being to focus on contributing to CPython. We will be blogging about our experience (probably using GitHub pages) - I'll send out the URL when it's been set up. Having spoken to people about this at PyCon UK this year and emailed on the core-mentorship mailing list, I'm posting here looking for any core devs who would be happy to provide us with some guidance. I'm wary of PR reviews being a blocker, and not wanting my co-contributors to feel disheartened by issues they're working on not reaching a resolution. We're open to working on almost any area of CPython, although particular areas of interest/familiarity might be: CPython core, re, unittest, subprocess, asyncio, ctypes, typing. There would be scope for us to work in small teams to work on more substantial issues if that is seen as a useful way to contribute, otherwise we can start with some of the easier issues on bpo. Would anyone here be willing to offer some support to help us reach our full potential? Please don't hesitate to contact me if you're interested in any way, or if you have any advice. If this year is a success there's a high probability we would look to do a similar thing in future years (with the experience from this year already in the bag)! Thanks, Lewis

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[WARNING] Some users who downloaded the Python 3.5.8 .xz tarball got the wrong version
by Larry Hastings Oct. 31, 2019

Oct. 31, 2019

Due to awkward CDN caching, some users who downloaded the source code tarballs of Python 3.5.8 got a preliminary version instead of the final version. As best as we can tell, this only affects the .xz release; there are no known instances of users downloading an incorrect version of the .tgz file. If you downloaded "Python-3.5.8.tar.xz" during the first twelve hours of its release, you might be affected. It's easy to determine this for yourself. The file size (15,382,140 bytes) and MD5 checksum (4464517ed6044bca4fc78ea9ed086c36) published on the release page have always matched the correct version. Also, the GPG signature file will only report a "Good signature" for the correct .xz file (using "gpg --verify"). What's the difference between the two? The only difference is that the final version also merges a fix for Python issue tracker #38243: https://bugs.python.org/issue38243 The fix adds a call to "html.escape" at a judicious spot, line 896 in Lib/xmlrpc/server.py. The only other changes are one new test, to ensure this new code is working, and an entry in the NEWS file. You can see the complete list of changes here: https://github.com/python/cpython/pull/16516/files What should you do? It's up to you. * If you and your users aren't using the XMLRPC library built in to Python, you don't need to worry about which version of 3.5.8 you downloaded. * If you downloaded the .tgz tarball or the Git repo, you already have the correct version. * If you downloaded the xz file and want to make sure you have the fix, check the MD5 sum, and if it's wrong download a fresh copy (and make sure that one matches the known good MD5 sum!). To smooth over this whole sordid mess, I plan to make a 3.5.9 release in the next day or so. It'll be identical to the 3.5.8 release; its only purpose is to ensure that all users have the same updated source code, including the fix for #38243. Sorry for the mess, everybody, //arry/

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small improvement idea for the CSV module
by Oz Tiram Oct. 31, 2019

Oct. 31, 2019

Hello Python-devs, The csv module is probably heavily utilized by newcomers to Python, being a very popular data exchange format. Although, there are better tools for processing tabular data like SQLite, or Pandas, I suspect this is still a very popular module. There are many examples floating around how one can read and process CSV with the csv module. Quite a few tutorials show how to use namedtuple to gain memory saving and speed, over the DictReader. Python's own documentation has got a recipe in the collections modules[1] Hence, I was wondering why not go the extra step and add a new class to the CSV module NamedTupleReader? This class would do a good service for Python's users, especially newcomers who are still not aware of modules like the collections module. Would someone be willing to sponsor and review such a PR from me? As a smaller change, we could simply add a link from the CSV module's documentation to the recipe in the collections module. What do you think? Best regards Oz [1]: https://docs.python.org/3/library/collections.html?highlight=namedtuple%20c… --- Imagine there's no countries it isn't hard to do Nothing to kill or die for And no religion too Imagine all the people Living life in peace

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[RELEASED] Python 3.5.8 is (finally) released
by Larry Hastings Oct. 29, 2019

Oct. 29, 2019

On behalf of the Python development community, I'm relieved to announce the availability of Python 3.5.8. Python 3.5 is in "security fixes only" mode. This new version only contains security fixes, not conventional bug fixes, and it is a source-only release. You can find Python 3.5.8 here: https://www.python.org/downloads/release/python-358/ Oh what fun, //arry/

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Adding GitHub usernames to the developer log
by Kyle Stanley Oct. 27, 2019

Oct. 27, 2019

Recently, Brett updated the developer log in the devguide (https://devguide.python.org/developers/) to fetch the names of each core developer and the date they were given commit privileges from the private python-committers repository. I think it would also be quite useful to include GitHub usernames on that list. Currently, the only list that contributors can find the GitHub usernames for each core developer is through the committers list on bpo. Since we will be moving away from bpo (PEP 581), we should have a comprehensive list that is separate from that platform. The motivation behind creating a a new topic for this issue was Brett's response to my comment in the PR that updated the devguide (https://github.com/python/devguide/pull/533#issuecomment-532405907). Essentially, if no core developers have an issue with having their GitHub username posted on the devguide, we can move forward with adding it. Another related but more long term project is adding the GitHub usernames to the experts index (https://devguide.python.org/experts/). This is more involved because the bpo nosy list currently pulls from the experts index, meaning the nosy list is dependent on the specific formatting used. To address this, I opened a PR a couple of months ago which would add a .json file containing the data from the experts index (https://github.com/python/devguide/pull/517), based on the discussion in the related issue (https://github.com/python/devguide/issues/507). If any available core developers are experienced with structuring .json files, I would greatly appreciate any feedback. The next step would be converting the nosy list script to use the new .json file instead of the experts index page, so that we could adjust the page to also include GitHub usernames. Optimally, the contents in the experts index would be pulled from the .json file automatically so any changes only have to be made to a single location.

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Allow custom headers in `http.server`
by Alex Yursha Oct. 27, 2019

Oct. 27, 2019

Hi CPython maintainers, I need to test my CORS setup and looking for a possibility to set a custom *Access-Control-Allow-Origin *header in http.server. As of now, there is no such feature. Are you interested in me writing a patch to contribute a feature of setting custom headers directly to `http.server`? Best, - Alex

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RFC: PEP 608: Coordinated Python release
by Victor Stinner Oct. 26, 2019

Oct. 26, 2019

Hi, I just posted a new PEP for comments, please reply there, rather than by email: https://discuss.python.org/t/rfc-pep-608-coordinated-python-release/2539 PEP 608: Coordinated Python release https://www.python.org/dev/peps/pep-0608/ Abstract: Block a Python release until a compatible version of selected projects is available. The Python release manager can decide to release Python even if a project is not compatible, if they decide that the project is going to be fixed soon enough, or if the issue severity is low enough. Victor -- Night gathers, and now my watch begins. It shall not end until my death.

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Summary of Python tracker Issues
by Python tracker Oct. 25, 2019

Oct. 25, 2019

ACTIVITY SUMMARY (2019-10-18 - 2019-10-25) 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 7066 ( -8) closed 43274 (+79) total 50340 (+71) Open issues with patches: 2793 Issues opened (51) ================== #30064: BaseSelectorEventLoop.sock_{recv,sendall}() don't remove their https://bugs.python.org/issue30064 reopened by yselivanov #38092: environment variables not passed correctly using new virtualen https://bugs.python.org/issue38092 reopened by eryksun #38519: Internal include files missing on Windows https://bugs.python.org/issue38519 opened by steve.dower #38520: There is no proper way to know if a process is the main one https://bugs.python.org/issue38520 opened by Delgan #38522: Py_USING_MEMORY_DEBUGGER is referenced in docs but not present https://bugs.python.org/issue38522 opened by Sümer.Cip #38523: ignore_dangling_symlinks in shutil.copytree does not apply rec https://bugs.python.org/issue38523 opened by veaviticus #38524: functools.cached_property is not supported for setattr https://bugs.python.org/issue38524 opened by hongweipeng #38526: zipfile.Path has the wrong method name https://bugs.python.org/issue38526 opened by tritium #38527: configure script fails to detect "float word ordering" on Sola https://bugs.python.org/issue38527 opened by wiggin15 #38529: Python 3.8 improperly warns about closing properly closed stre https://bugs.python.org/issue38529 opened by Ron Frederick #38530: Offer suggestions on AttributeError https://bugs.python.org/issue38530 opened by pablogsal #38532: Missing decrefs in the _ctypes module https://bugs.python.org/issue38532 opened by ZackerySpytz #38533: v3.7.5 py script run ok with python.exe but not pythonw.exe (p https://bugs.python.org/issue38533 opened by 4evermaat #38534: Version 3.8.0 has released with a wrong MS KB number reference https://bugs.python.org/issue38534 opened by seahoh #38535: Incorrect col_offset for decorators with zero arguments (empty https://bugs.python.org/issue38535 opened by alexmojaki #38536: Trailing space in formatted currency with international=True a https://bugs.python.org/issue38536 opened by Jonas Aschenbrenner #38538: dictobject dictviews don't return NotImplemented for unrecogni https://bugs.python.org/issue38538 opened by mdk #38541: Performance degradation of attribute accesses in Python 3.7.4 https://bugs.python.org/issue38541 opened by ttrd #38544: test_venv: test_isolation() failed on AMD64 Windows7 SP1 3.x: https://bugs.python.org/issue38544 opened by vstinner #38546: test_concurrent_futures: reap_children() warnings on RHEL7 and https://bugs.python.org/issue38546 opened by vstinner #38547: test_pty fails when using setsid() https://bugs.python.org/issue38547 opened by vstinner #38549: Compiler build paths and related environment variables are ign https://bugs.python.org/issue38549 opened by Alex Grund #38550: hashlib missing algorithms https://bugs.python.org/issue38550 opened by floppymaster #38552: Colored Prompt broken in REPL in Windows in 3.8 https://bugs.python.org/issue38552 opened by MinchinWeb #38553: Document functools.cached_property supports value updating and https://bugs.python.org/issue38553 opened by Epic_Wink #38554: A fatal error in test_descr https://bugs.python.org/issue38554 opened by ZackerySpytz #38557: PyTuple_GetSlice docs minor inaccuracy https://bugs.python.org/issue38557 opened by wim.glenn #38558: Data Structures documentation out of sync with new Walrus oper https://bugs.python.org/issue38558 opened by Matt Ward #38560: Allow iterable argument unpacking after a keyword argument? https://bugs.python.org/issue38560 opened by brandtbucher #38561: multiprocessing.Queue fails intermittently with "Broken pipe" https://bugs.python.org/issue38561 opened by Samuel Grayson #38564: test_asyncio: test_run_coroutine_threadsafe_with_timeout() has https://bugs.python.org/issue38564 opened by vstinner #38565: Expose the value passed of typed passed to functools.lru_cache https://bugs.python.org/issue38565 opened by Scott Sanderson2 #38566: Description of '\w' behavior is vague in `re` documentation https://bugs.python.org/issue38566 opened by snoopjedi #38567: urllib.parse.unquote_plus raises incorrect error message when https://bugs.python.org/issue38567 opened by stein-k #38569: Unknown distribution option: 'license_files' https://bugs.python.org/issue38569 opened by Marco Sulla #38570: Shlex does not parse commands containing single quotes correct https://bugs.python.org/issue38570 opened by timonegk #38571: Segfault with StopIteration https://bugs.python.org/issue38571 opened by kchen #38572: Misleading AttributeError accessing fileno attribute in tarfil https://bugs.python.org/issue38572 opened by xtreak #38573: Not Implemented Error in stdLib HTMLParser https://bugs.python.org/issue38573 opened by yevgenyp #38575: Child process deadlock in subprocess.Popen https://bugs.python.org/issue38575 opened by Zhipeng Xie #38576: CVE-2019-18348: CRLF injection via the host part of the url pa https://bugs.python.org/issue38576 opened by rschiron #38578: test_concurrent_futures failed on AMD64 FreeBSD Shared 3.8 https://bugs.python.org/issue38578 opened by vstinner #38579: 'u' formatted arrays mostly prevent appends of 4 byte characte https://bugs.python.org/issue38579 opened by bup #38580: select()'s documentation claims only sequences are accepted, b https://bugs.python.org/issue38580 opened by jstasiak #38582: re: backreference number in replace string can't >= 100 https://bugs.python.org/issue38582 opened by veaba #38583: The activate script in Windows is not correct for venvs create https://bugs.python.org/issue38583 opened by Mo #38584: argparse: Specifying a whitespace-only help message to a posit https://bugs.python.org/issue38584 opened by Lucas Cimon #38585: defusedexpat not supported past python 3.3/3.4 https://bugs.python.org/issue38585 opened by Avi Kelman #38586: logging: handlers names are not set when using fileConfig https://bugs.python.org/issue38586 opened by Lucas Cimon #38588: Use-after-free in dict/list https://bugs.python.org/issue38588 opened by LCatro #38589: Bad target address assigned in Python Manuals shortcut on Pyth https://bugs.python.org/issue38589 opened by Y3Kv Bv Most recent 15 issues with no replies (15) ========================================== #38589: Bad target address assigned in Python Manuals shortcut on Pyth https://bugs.python.org/issue38589 #38586: logging: handlers names are not set when using fileConfig https://bugs.python.org/issue38586 #38585: defusedexpat not supported past python 3.3/3.4 https://bugs.python.org/issue38585 #38580: select()'s documentation claims only sequences are accepted, b https://bugs.python.org/issue38580 #38579: 'u' formatted arrays mostly prevent appends of 4 byte characte https://bugs.python.org/issue38579 #38576: CVE-2019-18348: CRLF injection via the host part of the url pa https://bugs.python.org/issue38576 #38575: Child process deadlock in subprocess.Popen https://bugs.python.org/issue38575 #38572: Misleading AttributeError accessing fileno attribute in tarfil https://bugs.python.org/issue38572 #38570: Shlex does not parse commands containing single quotes correct https://bugs.python.org/issue38570 #38567: urllib.parse.unquote_plus raises incorrect error message when https://bugs.python.org/issue38567 #38561: multiprocessing.Queue fails intermittently with "Broken pipe" https://bugs.python.org/issue38561 #38558: Data Structures documentation out of sync with new Walrus oper https://bugs.python.org/issue38558 #38557: PyTuple_GetSlice docs minor inaccuracy https://bugs.python.org/issue38557 #38552: Colored Prompt broken in REPL in Windows in 3.8 https://bugs.python.org/issue38552 #38547: test_pty fails when using setsid() https://bugs.python.org/issue38547 Most recent 15 issues waiting for review (15) ============================================= #38586: logging: handlers names are not set when using fileConfig https://bugs.python.org/issue38586 #38584: argparse: Specifying a whitespace-only help message to a posit https://bugs.python.org/issue38584 #38567: urllib.parse.unquote_plus raises incorrect error message when https://bugs.python.org/issue38567 #38565: Expose the value passed of typed passed to functools.lru_cache https://bugs.python.org/issue38565 #38558: Data Structures documentation out of sync with new Walrus oper https://bugs.python.org/issue38558 #38554: A fatal error in test_descr https://bugs.python.org/issue38554 #38550: hashlib missing algorithms https://bugs.python.org/issue38550 #38536: Trailing space in formatted currency with international=True a https://bugs.python.org/issue38536 #38535: Incorrect col_offset for decorators with zero arguments (empty https://bugs.python.org/issue38535 #38534: Version 3.8.0 has released with a wrong MS KB number reference https://bugs.python.org/issue38534 #38532: Missing decrefs in the _ctypes module https://bugs.python.org/issue38532 #38530: Offer suggestions on AttributeError https://bugs.python.org/issue38530 #38527: configure script fails to detect "float word ordering" on Sola https://bugs.python.org/issue38527 #38519: Internal include files missing on Windows https://bugs.python.org/issue38519 #38517: functools.cached_property should support partial functions and https://bugs.python.org/issue38517 Top 10 most discussed issues (10) ================================= #38530: Offer suggestions on AttributeError https://bugs.python.org/issue38530 17 msgs #20443: __code__. co_filename should always be an absolute path https://bugs.python.org/issue20443 15 msgs #38582: re: backreference number in replace string can't >= 100 https://bugs.python.org/issue38582 11 msgs #38533: v3.7.5 py script run ok with python.exe but not pythonw.exe (p https://bugs.python.org/issue38533 10 msgs #38565: Expose the value passed of typed passed to functools.lru_cache https://bugs.python.org/issue38565 9 msgs #38524: functools.cached_property is not supported for setattr https://bugs.python.org/issue38524 7 msgs #1635741: Py_Finalize() doesn't clear all Python objects at exit https://bugs.python.org/issue1635741 6 msgs #34028: Python 3.7.0 wont compile with SSL Support 1.1.0 > alledged mi https://bugs.python.org/issue34028 5 msgs #38323: asyncio: MultiLoopWatcher has a race condition (test_asyncio: https://bugs.python.org/issue38323 5 msgs #38546: test_concurrent_futures: reap_children() warnings on RHEL7 and https://bugs.python.org/issue38546 5 msgs Issues closed (77) ================== #6741: Garbage collector release method https://bugs.python.org/issue6741 closed by vstinner #8787: warnings inside PyRun_SimpleString() display argv[1] https://bugs.python.org/issue8787 closed by vstinner #9098: MSYS build fails with `S_IXGRP' undeclared https://bugs.python.org/issue9098 closed by vstinner #12179: Race condition using PyGILState_Ensure on a new thread https://bugs.python.org/issue12179 closed by vstinner #12232: embedded python import cmath https://bugs.python.org/issue12232 closed by vstinner #12598: Move sys variable initialization from import.c to sysmodule.c https://bugs.python.org/issue12598 closed by vstinner #12919: Control what module is imported first https://bugs.python.org/issue12919 closed by vstinner #13131: FD leak in urllib2 https://bugs.python.org/issue13131 closed by vstinner #13562: Notes about module load path https://bugs.python.org/issue13562 closed by vstinner #13986: ValueError: cannot convert float NaN to integer https://bugs.python.org/issue13986 closed by vstinner #15047: Cygwin install (regen) problem https://bugs.python.org/issue15047 closed by vstinner #16353: add function to os module for getting path to default shell https://bugs.python.org/issue16353 closed by vstinner #16381: Introduce option to force the interpreter to exit upon MemoryE https://bugs.python.org/issue16381 closed by vstinner #17922: Crash in clear_weakref https://bugs.python.org/issue17922 closed by vstinner #17978: Python crashes if Py_Initialize/Py_Finalize are called multipl https://bugs.python.org/issue17978 closed by vstinner #21387: Memory leaks when embedded interpreter is reinitialized https://bugs.python.org/issue21387 closed by vstinner #22385: Define a binary output formatting mini-language for *.hex() https://bugs.python.org/issue22385 closed by gregory.p.smith #23496: Steps for Android Native Build of Python 3.4.2 https://bugs.python.org/issue23496 closed by vstinner #25430: speed up ipaddress __contain__ method https://bugs.python.org/issue25430 closed by xtreak #26888: Multiple memory leaks after raw Py_Initialize and Py_Finalize. https://bugs.python.org/issue26888 closed by vstinner #27530: Non-Critical Compiler WARNING: Python Embedding C++11 does not https://bugs.python.org/issue27530 closed by vstinner #27657: urlparse fails if the path is numeric https://bugs.python.org/issue27657 closed by vstinner #28202: Python 3.5.1 C API, the global variable is not destroyed when https://bugs.python.org/issue28202 closed by vstinner #28562: test_asyncio fails on Android upon calling getaddrinfo() https://bugs.python.org/issue28562 closed by vstinner #30618: readlink for pathlib paths https://bugs.python.org/issue30618 closed by gregory.p.smith #30735: Python 3.6.1 test_asyncio fails on Solaris 11 https://bugs.python.org/issue30735 closed by vstinner #31074: Startup failure if executable is a \\?\ path on Windows https://bugs.python.org/issue31074 closed by vstinner #31670: Associate .wasm with application/wasm https://bugs.python.org/issue31670 closed by xtreak #32026: Memory leaks in Python on Windows https://bugs.python.org/issue32026 closed by vstinner #32080: Re locale test fails after installing Python 3.6.3 on ubuntu 1 https://bugs.python.org/issue32080 closed by vstinner #32496: lib2to3 fails to parse a ** of a conditional expression https://bugs.python.org/issue32496 closed by gregory.p.smith #32526: Closing async generator while it is running does not raise an https://bugs.python.org/issue32526 closed by yselivanov #33348: lib2to3 doesn't parse f(*[] or []) https://bugs.python.org/issue33348 closed by gregory.p.smith #33384: Build does not work with closed stdin on NetBSD https://bugs.python.org/issue33384 closed by vstinner #33463: Can namedtuple._asdict return a regular dict instead of Ordere https://bugs.python.org/issue33463 closed by rhettinger #34316: test_socket and test_asyncio timeouts in AMD64 Windows10 3.x b https://bugs.python.org/issue34316 closed by vstinner #35473: Intel compiler (icc) does not fully support C11 Features, incl https://bugs.python.org/issue35473 closed by vstinner #36107: aarch64 python3 buffer overflow with stack protector on rpi3 ( https://bugs.python.org/issue36107 closed by vstinner #36752: test multiprocessing: test_rapid_restart() crash on AIX when u https://bugs.python.org/issue36752 closed by vstinner #37285: Python 2.7 setup.py incorrectly double-joins SDKROOT https://bugs.python.org/issue37285 closed by ned.deily #37415: Error build Python with Intel compiler: <stdatomic.h> doesn't https://bugs.python.org/issue37415 closed by vstinner #37911: Minor error in PEP567 code example https://bugs.python.org/issue37911 closed by xtreak #37922: inspect.getsource returns wrong class definition when multiple https://bugs.python.org/issue37922 closed by xtreak #38172: Python 3.8 Segfult with Bandersnatch pytest Suite https://bugs.python.org/issue38172 closed by vstinner #38208: Simplify string.Template by using __init_subclass__() https://bugs.python.org/issue38208 closed by serhiy.storchaka #38303: Make audioop PEP-384 compatible https://bugs.python.org/issue38303 closed by Tyler Kieft #38340: ERROR WHILE BUILDING pyworld for x86_64-linux-gnu-gcc https://bugs.python.org/issue38340 closed by xtreak #38395: proxy_contains (weakref.proxy) can access an object with 0 ref https://bugs.python.org/issue38395 closed by benjamin.peterson #38419: The path of check-c-globals.py on README is wrong https://bugs.python.org/issue38419 closed by corona10 #38433: 2.7.17rc1 tcl/tk version regression on Windows https://bugs.python.org/issue38433 closed by steve.dower #38448: test_concurrent_futures: reap_children() reaped child process https://bugs.python.org/issue38448 closed by vstinner #38457: __package__ is None in __init__.py until an import is used https://bugs.python.org/issue38457 closed by ncoghlan #38465: The type of ob_exports in PyByteArrayObject become Py_ssize_t. https://bugs.python.org/issue38465 closed by serhiy.storchaka #38466: [Easy doc] threading.excepthook doc talks about "object" https://bugs.python.org/issue38466 closed by vstinner #38493: os.CLD_KILLED and os.CLD_STOPPED should be implemented https://bugs.python.org/issue38493 closed by serhiy.storchaka #38521: Error in NormalDist.__eq__ https://bugs.python.org/issue38521 closed by rhettinger #38525: Strange reversed dict behavior https://bugs.python.org/issue38525 closed by pablogsal #38528: Docs for 2.7 version switcher still shows 3.8 as pre https://bugs.python.org/issue38528 closed by ned.deily #38531: argparse action "extend" not documented as new https://bugs.python.org/issue38531 closed by rhettinger #38537: 2.7 on Windows: all-users installation does not clear previous https://bugs.python.org/issue38537 closed by zach.ware #38539: Update demo files https://bugs.python.org/issue38539 closed by rhettinger #38540: Possible leaks in PyArg_Parse for "es#" and "et#" https://bugs.python.org/issue38540 closed by serhiy.storchaka #38542: [3.7] clean extern PyGC_Head *_PyGC_generation0; in Include/ob https://bugs.python.org/issue38542 closed by vstinner #38543: [2.7] Expose Py_TabcheckFlag as other PyAPI_DATA flag https://bugs.python.org/issue38543 closed by egaudry #38545: Implement setter and deleter on functools.cached_property https://bugs.python.org/issue38545 closed by Epic_Wink #38548: open() and file.write() without file.close() https://bugs.python.org/issue38548 closed by vstinner #38551: lib2to3 Grammar.txt doesn't have Python 3.8 grammar changes https://bugs.python.org/issue38551 closed by Peter Ludemann #38555: Undefined behavior in dictreviter_iternext https://bugs.python.org/issue38555 closed by serhiy.storchaka #38556: Walrus operator in list comprehensions [Python 3.8.0] https://bugs.python.org/issue38556 closed by eric.smith #38559: async generators aclose() behavior in 3.8 https://bugs.python.org/issue38559 closed by yselivanov #38562: pip install --upgrade git submodule update --recursive does no https://bugs.python.org/issue38562 closed by xtreak #38563: ProactorEventLoop.close(): set_wakeup_fd() only works in main https://bugs.python.org/issue38563 closed by vstinner #38568: [3.7.5 x86_64 Linux] f-string parsing results in EOL https://bugs.python.org/issue38568 closed by zach.ware #38574: Dataclasses documentation should show the necessary imports https://bugs.python.org/issue38574 closed by eric.smith #38577: OPENSSL_* flags not propagated to extensions during build https://bugs.python.org/issue38577 closed by Björn Pollex #38581: Crash on distutils/util.py when header variable isn't a string https://bugs.python.org/issue38581 closed by vstinner #38587: __set_name__ missing from descriptor howto documentation https://bugs.python.org/issue38587 closed by rhettinger

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Helpers for dynamic bytecode generation
by Yonatan Zunger Oct. 25, 2019

Oct. 25, 2019

Hi everyone, I've found myself recently writing Python code that dynamically generates bytecode.¹ I now have yet another case where I'm having to do this, in which my nice situation of being able to easily precompute all the jump addresses no longer holds. So I'm starting to write a helper to make it easy to write bytecode from Python, with its basic API calls being write(opcode, arg) and nextLine(optional label). The argument can be an int, name, local name, constant, label, etc., depending on the opcode, and it maintains all the appropriate tables and finally dumps a code object at the end. All of which is well and good and makes life much easier, but... I am *not* looking forward to writing the logic that basically duplicates that of assemble() in compile.c, of splitting all of this into basic blocks and computing the correct jump positions and so on before finally dumping out the bytecode. Has anyone already done this that people know of? (Searching the Internetz didn't turn anything up) Failing that, to what extent is it reasonable to either consider assemble() as some kind of sane API point into compile.c, and/or add some new API in compile.h which implements all of the stuff described above in C? (I'm fully expecting the answer to these latter questions to be "you have got to be kidding me," but figured it was wiser to check than to reinvent this particular wheel if it isn't necessary) Yonatan ¹ Not out of masochism, in case you're wondering; there was a real use case. A storage system would receive a read request that specified a bunch of (key, condition) pairs, where conditions where either return any value, return an exact value, or return values in a range. It would then receive between 1 and 1M (depending on the request parameters) candidate cells from the underlying storage layers, each of which had a tuple of bytes as its actual key values; it had to compare each of those tuples against the request parameters, and yield the values which matched. Because it's an inner loop and can easily be called 1M times, doing this in pure Python slows things down by a lot. Because it's also only called once, doing some really expensive overhead like synthesizing Python code and calling compile() on it would also slow things down a lot. But converting a bunch of (key, condition) pairs to a really efficient function from tuples of bytes to bools was pretty easy.

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4 first-time contributions that need core review.
by Brandt Bucher Oct. 23, 2019

Oct. 23, 2019

Hi all. There are a few *very simple* PRs from first-time contributors that have been sitting un-core-reviewed for several weeks. https://github.com/python/cpython/pull/16680: bpo-38419: fix "check-c-globals" path https://github.com/python/cpython/pull/16678: bpo-38421: Update email.utils documentation https://github.com/python/cpython/pull/16557: bpo-38361: syslog: fixed making default "ident" from sys.argv[0] https://github.com/python/cpython/pull/16438: bpo-38293: Allow shallow and deep copying of property objects I've reviewed them and they look good. If somebody has a small bit of time to look at these, I'm sure the authors would appreciate it!

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