Use positional-only parameters for some special methods

[serhiy-storchaka]

Feature or enhancement

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Proposal:

Most special methods (double underscored from both sizes) are only called with positional arguments. But some implementations forgot to add / in Argument Clinic description. It makes the code unnecessary complex and prevent using the efficient limited C API for it (Argument Clinic does not yet fully support the limited C API for keyword parameters).

We can just add missed /. No deprecation period is needed as these functions were not purposed to be used with keyword arguments.

Linked PRs

• gh-108635: Make parameters of some implementations of special methods positional-only #108636

[serhiy-storchaka]

They should have positional-only parameters:

typevar.__typing_subst__($self, /, arg)
paramspec.__typing_subst__($self, /, arg)
paramspec.__typing_prepare_subst__($self, /, alias, args)
typevartuple.__typing_subst__($self, /, arg)
typevartuple.__typing_prepare_subst__($self, /, alias, args)
winreg.HKEYType.__exit__($self, /, exc_type, exc_value, traceback)