Add SoftDeprecationWarning warning category

[vstinner]

Implementation of my proposed PEP 387 "Soft Deprecation" policy: python/peps#3182

• Add SoftDeprecationWarning warning category
• Ignore these warnings by default, except in the __main__ module (similar to PEP 565: Show DeprecationWarning in main)

As an example, I propose to soft deprecate the getopt module: PR #105735 (currently, the PR uses a regular "hard" deprecation).

Linked PRs

• gh-106137: Add SoftDeprecationWarning category #106142

[terryjreedy]

This seems like a new feature. Is there any discussion that you can link to? Such as about the PEP?

[hugovk]

Discussion is ongoing at https://discuss.python.org/t/formalize-the-concept-of-soft-deprecation-dont-schedule-removal-in-pep-387-backwards-compatibility-policy/27957

[vstinner]

This seems like a new feature. Is there any discussion that you can link to? Such as about the PEP?

Yes, see the first link in the issue :-)

Implementation of my proposed PEP 387 "Soft Deprecation" policy: python/peps#3182

=> python/peps#3182

Also, @hugovk gave the link to the discussion.