BLD: Drop Python 3.10 support

[wirable23]

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Question about pandas

Per spec0, python 3.10 support should be dropped. Will pandas 3 still support it?

[rhshadrach]

I believe we follow NumPy who has adopted Spec0, which means we should drop support with pandas 3.0 (or even 2.3?).

cc @jorisvandenbossche @WillAyd @mroeschke

[WillAyd]

I think 2.3 will continue to support 3.10 but yea probably worth dropping by the time 3.0 gets out

[jorisvandenbossche]

I would also certainly keep support for 2.3 (there is not that much reason to drop it now and backport those changes IMO)

[simonjayhawkins]

The motivation for SPEC 0 - Minimum Supported Dependencies is that limiting the scope of supported dependencies helps reduce the maintenance burden, allowing developers to focus on adding features, fixing bugs, and optimizing performance.

SPEC 0 states that support for Python versions should be dropped 3 years after their initial release. Python 3.10 was released in October 2021 and so, according to the spec we now follow, should be dropped for the forthcoming 2.3 release.

We don't drop support for Python in patch releases and so if not dropped for 2.3, we would need to ensure support for all subsequent 2.3.x releases. If we follow previous release schedules this could be around 6 months.

I would also certainly keep support for 2.3 (there is not that much reason to drop it now and backport those changes IMO)

there is also not that much reason not to drop it?

[jorisvandenbossche]

there is also not that much reason not to drop it?

For a maintenance branch like 2.3, it's more work to drop it than to not drop it ..

Also, SPEC0 does not require you to drop a version immediately when allowed according to their schedule, only that it is fine to drop it from that point

[WillAyd]

I would add that maintaining 2.3 has already been rather challenging. The bar to put any changes into that which are not related to the string data type should be really high, and I don't think dropping 3.10 would be worth it