TRACKER: add support for Python 3.14

[jorisvandenbossche]

Overview issue to keep track of adding Python 3.14 support. We already have some known issues and work in progress, listing them here in addition with remaining items:

Fixing compatibilities:

• MNT: migrate from codecs.open to open #62073
• BUG: Python 3.14 may not increment refcount #61368
  • Move chained assignment detection to cython for Python 3.14 compat #62070

Adding CI/packaging support:

• TST: run python-dev CI on 3.14-dev #61950
• Enable building py 3.14 wheels + indicate support in pyproject.toml
  • DEPS: add Python 3.14 and 3.14t wheel builds #62318
  • PKG/DOC: indicate Python 3.14 support in pyproject.toml and release notes #62396

All Python 3.14 related issues: https://github.com/pandas-dev/pandas/issues?q=state%3Aopen%20label%3A%22Python%203.14%22

[EwoutH]

Any update on when Pandas Python 3.14 wheels are up on PyPI?

Python 3.14 release is expected in just two (!) weeks, and many packages depend on Pandas.

[jorisvandenbossche]

I am planning a 2.3.3 release (#62330) including Python 3.14 support later this week