Docs: Include built-in functions among weakly referenceable objects

[esadomer]

Summary

Include built-in functions in the list of objects that support weak references. The current text excludes functions written in C, although built-in functions have supported weak references since Python 3.5.

import weakref

assert weakref.ref(len)() is len

The wording names built-in functions specifically: it does not imply that every callable implemented in C supports weak references. For example, the list.append method descriptor still raises TypeError.

Validation

• Built CPython 3.16.0a0 from the checkout with PCbuild\build.bat -p x64 -d -M on Windows 10 x64 (MSVC 19.30).
• PCbuild\amd64\python_d.exe -m test test_weakref: SUCCESS (run=139, skipped=4).
• Verified the examples and boundary cases with the same debug interpreter.
• python -m sphinx -W --keep-going -j 1 -b html -d build/doctrees . build/html from Doc: incremental HTML build passed with Sphinx 8.2.3. The clean baseline build reported an existing duplicate customization label in using/windows.rst and reference/datamodel.rst.
• python -m sphinxlint Doc/library/weakref.rst, PCbuild\amd64\python_d.exe Tools\patchcheck\patchcheck.py, and git diff --check: passed.

This changes documentation only. No NEWS entry is needed. The full interpreter test suite was not run.

[read-the-docs-community]

Documentation build overview

📚 cpython-previews | 🛠️ Build #34831730 | 📁 Comparing 49033d9 against main (84d4601)

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1 file changed

± library/weakref.html