Thanks for clarifying. On Tue, Jul 19, 2016 at 10:34 AM Nick Coghlan <ncogh...@gmail.com> wrote:
> 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 >
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