When creating an abstract class, subclassing tuple causes check for instantiation of an abstract class to be bypassed. See the associated stackoverflow question -- http://stackoverflow.com/questions/35267954/mix-in-of-abstract-class-and-namedtuple

    from abc import abstractmethod, ABCMeta

    class AbstactClass(tuple, metaclass=ABCMeta):

        @abstractmethod
        def some_method(self):
            pass

    # following should throw a TypeError, but doesn't
    AbstactClass()