# Core Development **URL:** https://discuss.python.org/c/core-dev/23.md [Latest](https://discuss.python.org/latest.md) · [Categories](https://discuss.python.org/categories.md) · [Tags](https://discuss.python.org/tags.md) --- ## [About the Core Development category](https://discuss.python.org/t/about-the-core-development-category/3628)
**Author:** [@brettcannon](https://discuss.python.org/u/brettcannon)\ **Replies:** 0\ **Last updated:** [March 3, 2020, 11:51pm UTC](https://discuss.python.org/t/about-the-core-development-category/3628 "2020-03-03T23:51:09Z")
Discussions relating to the development of Python (usage of Python should be discussed in the Python Help category, new ideas for Python to Ideas ). --- ## [Remove \_\_author\_\_, \_\_credits\_\_ and \_\_copyright\_\_ from stdlib modules](https://discuss.python.org/t/remove-author-credits-and-copyright-from-stdlib-modules/109199)
**Author:** [@Stanfromireland](https://discuss.python.org/u/Stanfromireland)\ **Replies:** 7\ **Last updated:** [September 26, 2026, 6:55am UTC](https://discuss.python.org/t/remove-author-credits-and-copyright-from-stdlib-modules/109199 "2026-09-26T06:55:02Z")
Around twenty stdlib modules, including json, io, inspect, and tarfile, still set \_\_author\_\_, \_\_credits\_\_ or \_\_copyright\_\_ attributes, mostly left over from when the modules were first added. $ git grep -E "\_\_(author|cr… --- ## [C API: Migrate embedded Python to PyConfig and PyInitConfig APIs](https://discuss.python.org/t/c-api-migrate-embedded-python-to-pyconfig-and-pyinitconfig-apis/109215)
**Author:** [@vstinner](https://discuss.python.org/u/vstinner)\ **Replies:** 0\ **Last updated:** [September 24, 2026, 4:18pm UTC](https://discuss.python.org/t/c-api-migrate-embedded-python-to-pyconfig-and-pyinitconfig-apis/109215 "2026-09-24T16:18:01Z")
Hi, I removed 21 deprecated global configuration variables and 4 deprecated functions in Python 3.16 C API. If your project embeds Python, it may affected if it doesn’t use PyConfig or PyInitConfig C API yet. I created … --- ## [Compiling CPython fails without wide-char NCurses](https://discuss.python.org/t/compiling-cpython-fails-without-wide-char-ncurses/109209)
**Author:** [@Deepfriedice](https://discuss.python.org/u/Deepfriedice)\ **Replies:** 2\ **Last updated:** [September 24, 2026, 1:19pm UTC](https://discuss.python.org/t/compiling-cpython-fails-without-wide-char-ncurses/109209 "2026-09-24T13:19:58Z")
I’m in the process of yak-shaving, and currently struggling to compile CPython. I’m trying to build NCurses locally without wide character support, and then build CPython that’s linked against that. To use the narrow ve… --- ## [Add \`!R\` conversion to f-string and \`str.format()\` to format error messages](https://discuss.python.org/t/add-r-conversion-to-f-string-and-str-format-to-format-error-messages/109098)
**Author:** [@vstinner](https://discuss.python.org/u/vstinner)\ **Replies:** 10\ **Last updated:** [September 23, 2026, 9:33am UTC](https://discuss.python.org/t/add-r-conversion-to-f-string-and-str-format-to-format-error-messages/109098 "2026-09-23T09:33:08Z")
Hi, I propose adding !R conversion format to f-string to format error messages and quote properly str subclasses. Example: class StrSubclass(str): def \_\_repr\_\_(self): return '\' abc = StrSubclass(… --- ## [What to do with re.LOCALE?](https://discuss.python.org/t/what-to-do-with-re-locale/32600)
**Author:** [@storchaka](https://discuss.python.org/u/storchaka)\ **Replies:** 11\ **Last updated:** [September 21, 2026, 12:47pm UTC](https://discuss.python.org/t/what-to-do-with-re-locale/32600 "2026-09-21T12:47:52Z")
The re.LOCALE flag and the (?L) mode modifier determine what is a letter and what characters are equal in case-insensitive mode in a byte pattern. It only works with byte strings, not Unicode strings. It only works in … --- ## [Deprecate the iterator interface of async generator \`asend\`/\`athrow\` objects](https://discuss.python.org/t/deprecate-the-iterator-interface-of-async-generator-asend-athrow-objects/109137)
**Author:** [@kumaraditya303](https://discuss.python.org/u/kumaraditya303)\ **Replies:** 4\ **Last updated:** [September 19, 2026, 8:04pm UTC](https://discuss.python.org/t/deprecate-the-iterator-interface-of-async-generator-asend-athrow-objects/109137 "2026-09-19T20:04:44Z")
I propose to deprecate \_\_iter\_\_ and \_\_next\_\_ on the async\_generator\_asend and async\_generator\_athrow types, leaving them with \_\_await\_\_, send, throw and close like coroutines as described in PEP 525. The motivation is… --- ## [Review request for PR #151425: document co\_linetable](https://discuss.python.org/t/review-request-for-pr-151425-document-co-linetable/109099)
**Author:** [@harjothkhara](https://discuss.python.org/u/harjothkhara)\ **Replies:** 2\ **Last updated:** [September 19, 2026, 2:59am UTC](https://discuss.python.org/t/review-request-for-pr-151425-document-co-linetable/109099 "2026-09-19T02:59:49Z")
Hi, I’d appreciate a review of PR #151425, a small documentation-only change that adds the currently undocumented code.co\_linetable attribute to the data model reference. The PR has been open for just over three months. … --- ## [Build provenance of openssl-bin-3.5.7 for CPython 3.14.6 on Windows](https://discuss.python.org/t/build-provenance-of-openssl-bin-3-5-7-for-cpython-3-14-6-on-windows/109109)
**Author:** [@168win](https://discuss.python.org/u/168win)\ **Replies:** 1\ **Last updated:** [September 18, 2026, 1:10pm UTC](https://discuss.python.org/t/build-provenance-of-openssl-bin-3-5-7-for-cpython-3-14-6-on-windows/109109 "2026-09-18T13:10:03Z")
Hello, I’m trying to establish the build provenance and configuration of the Windows x64 OpenSSL binaries used by CPython 3.14.6. CPython 3.14.6 selects the openssl-bin-3.5.7 branch from python/cpython-bin-deps. I foun… --- ## [PEP 842 postmortem: how do we protect the standard library?](https://discuss.python.org/t/pep-842-postmortem-how-do-we-protect-the-standard-library/108575)
**Author:** [@ZeroIntensity](https://discuss.python.org/u/ZeroIntensity)\ **Replies:** 54\ **Last updated:** [September 16, 2026, 10:44pm UTC](https://discuss.python.org/t/pep-842-postmortem-how-do-we-protect-the-standard-library/108575 "2026-09-16T22:44:55Z")
Hi, I recently wrote a proposal to hide private attributes from modules. My motivation for this was to prevent people from relying on stdlib internals. Now that the PEP has been withdrawn, I still think we need to find … --- ## [Why keep mimalloc 2.12?](https://discuss.python.org/t/why-keep-mimalloc-2-12/109040)
**Author:** [@clin1234](https://discuss.python.org/u/clin1234)\ **Replies:** 2\ **Last updated:** [September 15, 2026, 3:50pm UTC](https://discuss.python.org/t/why-keep-mimalloc-2-12/109040 "2026-09-15T15:50:44Z")
Right now, the free-threaded interpreter relies on a heavily patched version of mimalloc 2.12. Is there a particular reason why this old version is kept, and why CPython hasn’t migrated to a newer 2.x version (currently … --- ## [Semaphores for use with both threads and asyncio?](https://discuss.python.org/t/semaphores-for-use-with-both-threads-and-asyncio/109055)
**Author:** [@brittanyrey](https://discuss.python.org/u/brittanyrey)\ **Replies:** 4\ **Last updated:** [September 15, 2026, 1:31am UTC](https://discuss.python.org/t/semaphores-for-use-with-both-threads-and-asyncio/109055 "2026-09-15T01:31:38Z")
Hi! I’m currently adopting a program to use FT Python and went down a bit of a rabbit hole. The code bounds a shared resource with a semaphore, acquired from inside an asyncio event loop. With free threading, the code m… --- ## [Review request for #150326](https://discuss.python.org/t/review-request-for-150326/109013)
**Author:** [@edvilme](https://discuss.python.org/u/edvilme)\ **Replies:** 1\ **Last updated:** [September 14, 2026, 9:06pm UTC](https://discuss.python.org/t/review-request-for-150326/109013 "2026-09-14T21:06:57Z")
Hello. I submitted this PR a couple of weeks ago that has not gotten much attention. Who can I ask for a review? gh-150318: Fix \`\`quantiles(method=‘exclusive’)\`\` returning unsorted cut points for duplicate floats by edv… --- ## [Supporting Destructors in the TSS API](https://discuss.python.org/t/supporting-destructors-in-the-tss-api/108906)
**Author:** [@davidhewitt](https://discuss.python.org/u/davidhewitt)\ **Replies:** 4\ **Last updated:** [September 14, 2026, 3:12pm UTC](https://discuss.python.org/t/supporting-destructors-in-the-tss-api/108906 "2026-09-14T15:12:36Z")
We have been looking in PyO3 at using the Python Thread-Specific-Storage API to provide thread-local storage for extensions which don’t want to depend on the implementation in the Rust standard library. One feature whic… --- ## [Review request for PR #151828](https://discuss.python.org/t/review-request-for-pr-151828/109017)
**Author:** [@harjothkhara](https://discuss.python.org/u/harjothkhara)\ **Replies:** 0\ **Last updated:** [September 11, 2026, 5:38pm UTC](https://discuss.python.org/t/review-request-for-pr-151828/109017 "2026-09-11T17:38:06Z")
Hi, PR #151828 has been open since June 21. It fixes tarfile.open(..., mode="w|gz") raising struct.error when mtime is outside the 32-bit range, matching gzip and RFC 1952’s clamp-to-zero behavior. It includes boundary … --- ## [A benchmark de-noising skill for AI agent to optimize cpython](https://discuss.python.org/t/a-benchmark-de-noising-skill-for-ai-agent-to-optimize-cpython/109001)
**Author:** [@methane](https://discuss.python.org/u/methane)\ **Replies:** 0\ **Last updated:** [September 11, 2026, 8:22am UTC](https://discuss.python.org/t/a-benchmark-de-noising-skill-for-ai-agent-to-optimize-cpython/109001 "2026-09-11T08:22:06Z")
I was using Astra to work on optimizing CPython when the JIT is not enabled. I found several small improvements, and I plan to submit PRs for them. Throughout the optimization work, the instability of pyperformance was … --- ## [New contributor looking for guidance on my first CPython contribution](https://discuss.python.org/t/new-contributor-looking-for-guidance-on-my-first-cpython-contribution/108968)
**Author:** [@MAYANKSHARMA01010](https://discuss.python.org/u/MAYANKSHARMA01010)\ **Replies:** 3\ **Last updated:** [September 9, 2026, 10:46pm UTC](https://discuss.python.org/t/new-contributor-looking-for-guidance-on-my-first-cpython-contribution/108968 "2026-09-09T22:46:15Z")
Hi everyone, I’m a student/developer interested in contributing to CPython and I’d like to start with a beginner-friendly issue. I’m comfortable with Python and Git/GitHub, but I’m new to contributing to CPython itself… --- ## [Review request for Issue #92810](https://discuss.python.org/t/review-request-for-issue-92810/108965)
**Author:** [@dolfinus](https://discuss.python.org/u/dolfinus)\ **Replies:** 0\ **Last updated:** [September 9, 2026, 8:39am UTC](https://discuss.python.org/t/review-request-for-issue-92810/108965 "2026-09-09T08:39:49Z")
There is an issue #92810 - isinstance(ABC\_subclass, ...)/issubclass(ABC\_subclass, ...) can consume gigabytes of RAM if few thousand unlrelated classes are created and compared with each other. There are 4 related PRs: a… --- ## [\[Experimental\] Tracing GC (by Codex)](https://discuss.python.org/t/experimental-tracing-gc-by-codex/108961)
**Author:** [@methane](https://discuss.python.org/u/methane)\ **Replies:** 0\ **Last updated:** [September 9, 2026, 3:07am UTC](https://discuss.python.org/t/experimental-tracing-gc-by-codex/108961 "2026-09-09T03:07:28Z")
I participate in the Codex OSS Program, but I end up with a lot of unused AI credits every week. So I decided to have the latest model explore some ideas that I had been interested in but hadn’t been able to investigate … --- ## [Review request for PR #152984](https://discuss.python.org/t/review-request-for-pr-152984/108918)
**Author:** [@yuanx749](https://discuss.python.org/u/yuanx749)\ **Replies:** 0\ **Last updated:** [September 7, 2026, 8:12am UTC](https://discuss.python.org/t/review-request-for-pr-152984/108918 "2026-09-07T08:12:39Z")
Hi, PR #152984 has been open for more than one month. It fixes a KeyError when passing member names with trailing slashes from getnames() to extract() in tarfile. I’d appreciate a review when someone has time. Thanks! --- ## [Python 3.12.14, 3.11.16 and 3.10.21 are now available!](https://discuss.python.org/t/python-3-12-14-3-11-16-and-3-10-21-are-now-available/108537)
**Author:** [@thomas](https://discuss.python.org/u/thomas)\ **Replies:** 5\ **Last updated:** [September 5, 2026, 11:01am UTC](https://discuss.python.org/t/python-3-12-14-3-11-16-and-3-10-21-are-now-available/108537 "2026-09-05T11:01:53Z")
Python Releases Eclipse Your Security! New security releases for 3.10, 3.11 and 3.12 are now available. (As these Python versions are now in security-fix-only mode, these are source-only releases, and there is no pre-set… --- ## [Isn’t gh-109638 a security problem? Doesn’t it deserve a CVE?](https://discuss.python.org/t/isn-t-gh-109638-a-security-problem-doesn-t-it-deserve-a-cve/108883)
**Author:** [@mcepl](https://discuss.python.org/u/mcepl)\ **Replies:** 4\ **Last updated:** [September 4, 2026, 6:00pm UTC](https://discuss.python.org/t/isn-t-gh-109638-a-security-problem-doesn-t-it-deserve-a-cve/108883 "2026-09-04T18:00:52Z")
When looking the pull request gh-154867 (fix for gh-98820, CVE-2026-18503), I saw just next PR gh-154868 (fix for gh-109638), which however doesn’t have CVE. Shouldn’t it? It is exactly same DoS problem as the other one,… --- ## [Getting exceptions & built-in types using \`Py\_GetConstant\`](https://discuss.python.org/t/getting-exceptions-built-in-types-using-py-getconstant/108861)
**Author:** [@encukou](https://discuss.python.org/u/encukou)\ **Replies:** 4\ **Last updated:** [September 4, 2026, 8:00am UTC](https://discuss.python.org/t/getting-exceptions-built-in-types-using-py-getconstant/108861 "2026-09-04T08:00:31Z")
I propose defining identifiers for use with Py\_GetConstant for exceptions (e.g. Py\_CONSTANT\_Exc\_ValueError to get ValueError) and other built-in types (e.g. Py\_CONSTANT\_Bool\_Type to get bool). When compiling for Stabl… --- ## [One time ABI breakage](https://discuss.python.org/t/one-time-abi-breakage/108514)
**Author:** [@markshannon](https://discuss.python.org/u/markshannon)\ **Replies:** 26\ **Last updated:** [September 3, 2026, 8:11am UTC](https://discuss.python.org/t/one-time-abi-breakage/108514 "2026-09-03T08:11:05Z")
Abstract I’d like to propose that we have a one time break in the stable ABI, such that extensions can be compiled into one of two builds: Support versions up to 3.15 Support version 3.12 (3.14 for 32 bit builds) and … --- ## [C API: Add \`Py\_GetBuildInType\` and \`Py\_GetBuildInTypeBorrowed\`](https://discuss.python.org/t/c-api-add-py-getbuildintype-and-py-getbuildintypeborrowed/107010)
**Author:** [@bschoenmaeckers](https://discuss.python.org/u/bschoenmaeckers)\ **Replies:** 21\ **Last updated:** [September 2, 2026, 1:08pm UTC](https://discuss.python.org/t/c-api-add-py-getbuildintype-and-py-getbuildintypeborrowed/107010 "2026-09-02T13:08:34Z")
This was originally posted at C API: Add \`Py\_GetBuildInType\` and \`Py\_GetBuildInTypeBorrowed\` · Issue #148643 · python/cpython · GitHub Currently, the C API exports all build-in types as a static data export. This limits… --- ## [Python 3.15.0 candidate 2 is here!](https://discuss.python.org/t/python-3-15-0-candidate-2-is-here/108841)
**Author:** [@hugovk](https://discuss.python.org/u/hugovk)\ **Replies:** 1\ **Last updated:** [September 1, 2026, 9:19pm UTC](https://discuss.python.org/t/python-3-15-0-candidate-2-is-here/108841 "2026-09-01T21:19:14Z")
It’s the final 3.15 release candidate! This is a candidate preview of Python 3.15 This release, 3.15.0rc2, is the final planned candidate release, containing around 144 bugfixes, build improvements and documentation … --- ## [Python install manager 26.4](https://discuss.python.org/t/python-install-manager-26-4/108846)
**Author:** [@steve.dower](https://discuss.python.org/u/steve.dower)\ **Replies:** 0\ **Last updated:** [September 1, 2026, 1:05pm UTC](https://discuss.python.org/t/python-install-manager-26-4/108846 "2026-09-01T13:05:18Z")
Along with Python 3.15.0rc2, the second beta of the next Python install manager release is also available. The changes in beta 1 are more interesting (though I forgot to post about them), but the two main changes are … --- ## [Deprecate the tuple API (object\[index\]) of structseq objects like os.stat\_result](https://discuss.python.org/t/deprecate-the-tuple-api-object-index-of-structseq-objects-like-os-stat-result/108464)
**Author:** [@vstinner](https://discuss.python.org/u/vstinner)\ **Replies:** 20\ **Last updated:** [August 31, 2026, 7:58pm UTC](https://discuss.python.org/t/deprecate-the-tuple-api-object-index-of-structseq-objects-like-os-stat-result/108464 "2026-08-31T19:58:27Z")
Hi, I propose deprecating os.stat(filename)\[8\] tuple API to migrate to os.stat(filename).st\_mtime named attributes. The tuple API exists for backward compatibility with Python 2.1 and older which was released 25 years … --- ## [Python vulnerabilities document is ready for IS/IEC review](https://discuss.python.org/t/python-vulnerabilities-document-is-ready-for-is-iec-review/108773)
**Author:** [@stephengmichell](https://discuss.python.org/u/stephengmichell)\ **Replies:** 1\ **Last updated:** [August 27, 2026, 3:42pm UTC](https://discuss.python.org/t/python-vulnerabilities-document-is-ready-for-is-iec-review/108773 "2026-08-27T15:42:50Z")
I convene ISO/IEC/JTC 1/SC 22/WG 23 Programming Language Vulnerabilities working group. He have, and are producing a set of documents that detail programming language vulnerabilities in general and in specific languages.… --- ## [Redesigning the \`turtle\` docstring translation process](https://discuss.python.org/t/redesigning-the-turtle-docstring-translation-process/108750)
**Author:** [@Stanfromireland](https://discuss.python.org/u/Stanfromireland)\ **Replies:** 7\ **Last updated:** [August 27, 2026, 4:37am UTC](https://discuss.python.org/t/redesigning-the-turtle-docstring-translation-process/108750 "2026-08-27T04:37:39Z")
turtle supports translation of its docstrings via turtle.write\_docstringdict, however no catalogues have ever been widely distributed (from what I can tell), and the documentation still directs requests to a personal ema… [Next page](https://discuss.python.org/c/core-dev/23.md?page=1)