Writer APIs for str and bytes should be public

[malemburg]

These are useful when creating larger strings or bytes arrays from C and hide away the details of the usual allocate/write/resize dance, which was the default way of doing things before we had the writer APIs (the str object still supports this via PyUnicode_Resize(), bytes do so as well, but only via the private _PyString_Resize()).

[gvanrossum]

@malemburg To make it easier to find this issue when searching for APIs, and to find the APIs you propose to make public, can you name the specific APIs please?

[vstinner]

I proposed a new PyUnicodeWriter API which was just approved by the C API WG: capi-workgroup/decisions#27

The _PyBytesWriter API is still private.

[malemburg]

I proposed a new PyUnicodeWriter API which was just approved by the C API WG: capi-workgroup/decisions#27

Great. Would have been nice to ping me on this for comments, since I was not aware of your proposal.

The _PyBytesWriter API is still private.

This should be made public in the same way.

[vstinner]

Writer APIs for str and bytes should be public

I just created python/cpython#121710 [C API] Add PyBytesWriter API.

Great. Would have been nice to ping me on this for comments, since I was not aware of your proposal.

I wasn't aware of this issue. I found it after the decision was taken on PyUnicodeWriter.

[vstinner]

This issue has been solved by adding the PyUnicodeWriter API to Python 3.14 and the PyBytesWriter API to Python 3.15. 💖