On 19 July 2016 at 16:41, Neil Girdhar <mistersh...@gmail.com> wrote: > Yes, I see what you're saying. However, I don't understand why > __init_subclass__ (defined on some class C) cannot be used to implement the > checks required by @abstractmethod instead of doing it in ABCMeta. This > would prevent metaclass conflicts since you could use @abstractmethod with > any metaclass or no metaclass at all provided you inherit from C.
ABCMeta also changes how __isinstance__ and __issubclass__ work and adds additional methods (like register()), so enabling the use of @abstractmethod without otherwise making the type an ABC would be very confusing behaviour that we wouldn't enable by default. But yes, this change does make it possible to write a mixin class that implements the "@abstractmethod instances must all be overridden to allow instances to to be created" logic from ABCMeta without otherwise turning the class into an ABC instance. Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
