class A:
def get(self):
self.say()
def say(self):
print('AAAAA')
class B(A):
def say(self):
print('BBBBB')
b = B()
b.get()
class A(object):
pass
class B(A):
pass
print(isinstance(A(), A))
print(isinstance(B(), A))
print(type(A()) == A)
print(type(B()) == A)