python之属性继承

class A:
    a = 1

a, b, c = A(), A(),A()

print(a.a, b.a, c.a)

a.a = 2
A.a = 3
print(a.a, A.a, c.a)   # 未对实例c.a赋值，则会继承类属性a的值

print(a.__dict__, A.__dict__, c.__dict__)

# output:

(1, 1, 1)
(2, 3, 3)
({'a': 2}, {'a': 3, '__module__': '__main__', '__doc__': None}, {}) # 实例c的__dict__为空