def __lt__(self, other):
        """Returns 1 if the lhs set is contained but not equal to the rhs set."""
        if len(self.elems) < len(other.elems):
            temp = other.copy()
            for elem in self.elems:
                if elem in temp.elems:
                    temp.remove(elem)
                else:
                    return 0
            return len(temp.elems) == 0
        else:
            return 0
Returns 1 if the lhs set is contained but not equal to the rhs set.
recipes/Python/106469_Yet_another_Set_class_for_Python/recipe-106469.py