def subclasses(class_a, class_b):
    """
    Checks whether class_a is a subclass of class_b. Will also make sure it's not the same class
    :param class_a: Class to check
    :param class_b: Reference class to check against
    :return: True if A is an actual subclass of B
    """
    return issubclass(class_a, class_b) and class_a != class_b