On 10 November 2017 at 18:39, Koos Zevenhoven email@example.com wrote:
On Wed, Sep 27, 2017 at 12:28 PM, Ivan Levkivskyi firstname.lastname@example.org wrote:
After creating the class, the original bases are saved in ``__orig_bases__`` (currently this is also done by the metaclass).
Those are *still* bases, right, even if they are not in the mro? I'm not sure if this is a naming thing or something even more.
The objects that have __subclass_base__ method (proposed to rename to __mro_entry__) are removed from __bases__ attributed of the newly created class. Otherwise they may cause a metaclass conflict. One can however still call them syntactic (or static?) bases. For example this is how it is going to be used by typing:
from typing import List
class Tokens(List[int]): ...
assert Tokens.__bases__ == (list,)
NOTE: These two method names are reserved for exclusive use by
the ``typing`` module and the generic types machinery, and any other use is strongly discouraged.
Given the situation, that may be a good thing. But will it really work? I think it is also strongly discouraged to invent your own dunder method names, but people still do it.
Terry had a similar comment. I will "soften" this formulation in the next revision of the PEP.