class_constuctor.py

class AdapterFabric(type):
    """
    Return adapter object regarding to social network
    """

    instances = 0

    def __new__(cls, social, bases=(), dct={}):
        cls.instances += 1
        adapters = [YouTubeSocialAdapter, VKSocialAdapter]

        for Adapter in adapters:
            if getattr(Adapter, '__social__') == social:
                bases += (Adapter,)

        return type.__new__(cls, social, bases, dct)