Proposal: deprecation policy (details for classes)

[Kwankyu Lee]

Hi, 

From the discussion in 

    https://github.com/sagemath/sage/issues/38211 

motivated by the issue raised in 

    https://github.com/sagemath/sage/pull/38207,

we created a proposal to augment the current deprecation policy

    https://doc.sagemath.org/html/en/developer/coding_in_python.html#deprecation.

Here is the proposal:

(S) Only public functions, methods, attributes, classes living under sage are subject to the deprecation policy.

(M) Functions, methods, attributes, classes whose names start with an underscore are considered internal, and is not subject to the deprecation policy.

(C) A class whose name does not start with an underscore is public by default, but can be considered internal if experts agree that the class is unlikely to be directly imported by user code. If experts disagree, then it is public. For a PR changing the class, authors and reviewers are the experts.

Moreover https://github.com/sagemath/sage/issues/38211#issuecomment-2180309924 defines the standard procedure for deprecation of public classes.

If no one has major objections, we will proceed to update the developer guide to reflect the proposal. Comments are welcome. Thanks.

Kwankyu 

[Kwankyu Lee]

Here is the PR implementing the proposal:

https://github.com/sagemath/sage/pull/38273

[Kwankyu Lee]

Thanks for your attention, and no objection :-)

Here is the PR implementing the updated policy: https://github.com/sagemath/sage/pull/38273 in "needs review".

Kwankyu