[Python-Dev] PEP 384 status

["Martin v. Löwis"]

> On http://bugs.python.org/issue9778 you elaborated on what the PEP would
> entail in its current state:
> 
> “No, vice versa. The PEP promises that the ABI won't change until
> Python 4. For any change that might break the ABI, either a
> backwards-compatible solution needs to be found, or the change be
> deferred to Python 4.”
> 
> This sounds like it could be detrimental by blocking desired
> improvements (the aforementioned issue is a potential example of this).

Notice that it's only potential: in the specific case, there would be
an ABI-compatible way of introducing wide hashes, using a second type
slot.

> Do you think it would complicate things a lot to version the ABI itself?

It would miss the point. The ABI deliberately restricts itself to
features that really have been stable, and we should be committed to
keeping that subset stable.

If you think this is too restrictive, please point out specific aspects
that you think might need to change in the mid-term future. They should
then be excluded from the ABI.

> Actually, PYTHON_API_VERSION is already used as some kind of ABI tag
> (since it's checked at module load time rather than at compile time).

It's too late, though: when the module is being created, the code
using the ABI is already running. As I wrote in the issue: the *real*
ABI version is "python3.dll".

Regards,
Martin