如何检查类型是否是Python中的某个类型的子类型？

Question

我该如何检查一个类型是否是Python中的一个类型的子类型？我不是指一个类型的实例，而是比较类型实例本身。例如：

class A(object): 
    ... 

class B(A): 
    ... 

class C(object) 
    ... 

# Check that instance is a subclass instance: 
isinstance(A(), A) --> True 
isinstance(B(), A) --> True 
isinstance(C(), A) --> False 

# What about comparing the types directly? 
SOME_FUNCTION(A, A) --> True 
SOME_FUNCTION(B, A) --> True 
SOME_FUNCTION(C, A) --> False 

Answer 1

也许issubclass？

>>> class A(object): pass 
>>> class B(A): pass 
>>> class C(object): pass 
>>> issubclass(A, A) 
True 
>>> issubclass(B, A) 
True 
>>> issubclass(C, A) 
False