isinstance
isinstance(obj,cls)检查是否obj是否是类 cls 的对象
class A(object):
pass
a = A()
isinstance(a, A)
#true
issubclass
issubclass(sub, super)检查sub类是否是 super 类的子类
class A(object):
pass
class B(A):
pass
issubclass(B,A)
#true