You can use issubclass() like this assert issubclass(suit, Suit).
issubclass()
assert issubclass(suit, Suit)
issubclass(class, classinfo)
Excerpt:
Return true if class is a subclass (direct, indirect or virtual) of classinfo.
class
classinfo
You can use isinstance if you have an instance, or issubclass if you have a class. Normally thought its a bad idea. Normally in Python you work out if an object is capable of something by attempting to do that thing to it.
isinstance
issubclass