python描述器

[python]代码库

class A:
    def __init__(self):
        print('A init')
        self.a1 = 'a1'

    def __get__(self, instance, owner):
        print('A.__get__',self,instance,owner)
        return self

    def __set__(self, instance, value):
        print('A.__set__',self,instance,value)

class B:
    x = A()

    def __init__(self):
        print('B.init')
        # self.x = 100    #触发了类的set描述器,相当于操作类属性
        # self.x = A()
# print(B.x)
# print()
# print(B.x.a1)
# print()

b = B()
# print()
# print(B.x)
# print()
# print(b.x.a1)

b.x = 600
print(b.x)
print(b.__dict__)
# B.x = 500
print(B.__dict__)