factory_awesome.py

class Parent(object):

    def __new__(cls, to, *args, **kwargs):
        if hasattr(to, 'something'):
            return object.__new__(Child)
        return object.__new__(Parent)

    def send(self):
        raise RuntimeError('You must override the send method for this Parent subclass')

class Child(Parent):
    def __init__(self, to, *args, **kwargs):
        print(kwargs)