[Answered ]-Can I use a python metaclass to keep track of subclasses in separate files?

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This could be done with a decorator:

from SocialProvider import SocialProvider

@SocialProvider.Register
class NewSocialProvider( SocialProvider ):
    pass

I’ve assumed SocialProvider is a superclass written by you. If so, in your superclass file, the Register helper could be defined as a class method:

class SocialProvider:

    subclasses = []
    @classmethod
    def Register( cls, subcl ):
        cls.subclasses.append( subcl )
        return subcl

If not, then you could still define a function somewhere, to be used as a decorator, but it and the list it appends to would have to be defined somewhere else, separate from the SocialProvider class. You mention the problem of not-yet-imported files. There’s nothing you can do to detect a class that hasn’t been defined yet, so you’d have to make sure that the files with the subclass definitions are imported (e.g. via statements like import facebook etc in the ___init__.py file of your module).

👤jez

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