[Python-Dev] Making PyInterpreterState an opaque type

[Jeroen Demeyer]

On 2019-02-19 04:04, Steve Dower wrote:
> On 18Feb.2019 1324, Jeroen Demeyer wrote:
>> For a very concrete example, was it really necessary to put
>> _PyTuple_ITEMS in (4)? That's used in _functoolsmodule.c. Especially
>> given that the very similar PySequence_Fast_ITEMS is in (2), that seems
>> like a strange and arbitrary limiting choice.
>
> The reason to do this is that we can "guarantee" that we've fixed all
> users when we change the internal representation.

I think that CPython should then at least "eat its own dog food" and 
don't use any of the internal functions/macros when implementing the 
stdlib. As I said before: if a function/macro is useful for implementing 
stdlib functionality like "functools" or "json", it's probably useful 
for external modules too.