[C API] Add a banner to the C API documentation to recommend tools

[vstinner]

I propose adding a banner to all C API documentation pages to recommend using 3rd party tools, rather than using directly the C API.

See the discussion on HPy: https://discuss.python.org/t/c-api-working-group-and-plan-to-get-a-python-c-api-compatible-with-alternative-python-implementations/89477/41

Linked PRs

• gh-133678: Add a banner to C API doc to recommend 3rd party tools #133679
• gh-133678: Document C API third party tools #134526
• [3.13] gh-133678: Document C API third party tools (GH-134526) #134792
• [3.14] gh-133678: Document C API third party tools (GH-134526) #134793

[encukou]

-1. I think CPython should have a usable and stable C API for all stakeholders, and a list of a few blessed users goes against that goal.

Extend the current list with the ideas here, but please don't add a new one and don't link to it aggressively from every page.

[vstinner]

-1. I think CPython should have a usable and stable C API for all stakeholders,

The banner doesn't change anything to the C API maintenance. It will remain the same.

and a list of a few blessed users goes against that goal.

Do you mean that the list is too short? Or do you mean that developers should be able/"allowed" to write C extensions directly with the C API?

Extend the current list with the ideas here, but please don't add a new one and don't link to it aggressively from every page.

Why do you think that it's aggressive? Can you propose a different phrasing to make it not aggressive?

[encukou]

The banner doesn't change anything to the C API maintenance. It will remain the same.

What's the motivation for this change, then?

Do you mean that the list is too short? Or do you mean that developers should be able/"allowed" to write C extensions directly with the C API?

Both.

Why do you think that it's aggressive?

It's on every page of the reference.