Python 3.14 compatibility.

[Mariusz Felisiak]

Python 3.14 final is scheduled for October 2025 (see ​​PEP 745). This is a tracking ticket for compatibility fixes for Django submitted in the meantime.

Django 5.2 will be the first version to support Python 3.14, because Django 5.1 will end the mainstream support in April 2024.

[Mariusz Felisiak]

Initial PRs:

• ​https://github.com/django/django/pull/18686 - Added Python 3.14 to daily builds.
• ​https://github.com/django/django/pull/18680 - Fixed asyncio.iscoroutinefunction() deprecation warnings.
• ​https://github.com/django/django/pull/18685 - Fixed tests for test --parallel option.

After applying these 3 changes we'll have one more deprecation warning, 49 test failures, and 24 test errors. All of them are under investigation of Team Venus of the 3rd Djangonauts cohort, PRs will be submitted soonish :)

[GitHub <noreply@…>]

In 48fa531:

Refs #35844 -- Added Python 3.14 to daily builds.

[GitHub <noreply@…>]

In bd3b1dfa:

Refs #35844 -- Used asgiref.sync.iscoroutinefunction() instead of deprecated asyncio.iscoroutinefunction().

Fixes DeprecationWarning:

'asyncio.iscoroutinefunction' is deprecated and slated for removal in
Python 3.16; use inspect.iscoroutinefunction() instead.

[GitHub <noreply@…>]

In 34066d6:

Refs #35844 -- Fixed tests for test --parallel option on Python 3.14+.

"forkserver" is the new default on POSIX systems, and Django doesn't
support parallel tests with "forkserver":

​https://github.com/python/cpython/commit/b65f2cdfa77d8d12c213aec663ddaaa30d75a4b2

[Sarah Boyce <42296566+sarahboyce@…>]

In 4c3897b:

Refs #35844 -- Corrected expected error messages in commands tests on Python 3.14+.

Updated CommandTests.test_subparser_invalid_option and CommandDBOptionChoiceTests.test_invalid_choice_db_option to address changes in Python 3.14+ error handling.

[Mariusz Felisiak]

FYI: urljoin() behavior change has been accepted as a regression in Python 3.14, ​https://github.com/python/cpython/issues/125926.

[Claude Paroz <claude@…>]

In fc22fdd3:

Refs #35844 -- Expanded compatibility for expected error messages in command tests on Python 3.12 and 3.13.

Updated CommandTests.test_subparser_invalid_option and CommandDBOptionChoiceTests.test_invalid_choice_db_option to use assertRaisesRegex() for compatibility with modified error messages in Python 3.12, 3.13, and 3.14+..

[Sarah Boyce <42296566+sarahboyce@…>]

In b57a839:

[5.1.x] Refs #35844 -- Expanded compatibility for expected error messages in command tests on Python 3.12 and 3.13.

Updated CommandTests.test_subparser_invalid_option and CommandDBOptionChoiceTests.test_invalid_choice_db_option to use assertRaisesRegex() for compatibility with modified error messages in Python 3.12, 3.13, and 3.14+..

Backport of fc22fdd34f1e55adde161f5f2dca8db90bbfce80 from main.

[Sarah Boyce <42296566+sarahboyce@…>]

In 5064ddb:

[5.0.x] Refs #35844 -- Expanded compatibility for expected error messages in command tests on Python 3.12.

Updated CommandTests.test_subparser_invalid_option and CommandDBOptionChoiceTests.test_invalid_choice_db_option to use assertRaisesRegex() for compatibility with modified error messages in Python 3.12, 3.13, and 3.14+..

Backport of fc22fdd34f1e55adde161f5f2dca8db90bbfce80 from main.

[Sarah Boyce <42296566+sarahboyce@…>]

In ea4a1fb:

[4.2.x] Refs #35844 -- Expanded compatibility for expected error messages in command tests on Python 3.12.

Updated CommandTests.test_subparser_invalid_option and CommandDBOptionChoiceTests.test_invalid_choice_db_option to use assertRaisesRegex() for compatibility with modified error messages in Python 3.12, 3.13, and 3.14+..

Backport of fc22fdd34f1e55adde161f5f2dca8db90bbfce80 from main.

[Mariusz Felisiak]

Replying to Mariusz Felisiak:

FYI: urljoin() behavior change has been accepted as a regression in Python 3.14, ​https://github.com/python/cpython/issues/125926.

Fixed in ​https://github.com/python/cpython/commit/dbb6e22cb1f533bba00a61a5b63ec68af9d48836.

[Sarah Boyce <42296566+sarahboyce@…>]

In 8d7b142:

Refs #35844 -- Fixed copying BaseContext and its subclasses on Python 3.14+.

super objects are copyable on Python 3.14+:

​https://github.com/python/cpython/commit/5ca4e34bc1aab8321911aac6d5b2b9e75ff764d8

and can no longer be used in BaseContext.copy().

[Sarah Boyce <42296566+sarahboyce@…>]

In fcd9d08:

Refs #35844 -- Fixed OtherModelFormTests.test_prefetch_related_queryset() test on Python 3.14+.

​https://github.com/python/cpython/commit/5a23994a3dbee43a0b08f5920032f60f38b63071

[GitHub <noreply@…>]

In 0a341125:

Refs #35844 -- Removed unnecessary ArgumentParser.add_argument_group()'s prefix_chars argument.

The prefix_chars argument is deprecated since ​https://github.com/python/cpython/commit/7b04496e5c7ed47e9653f4591674fc9ffef34587.