class Foo:

    def __init__(self,name):

        self.name=name

    def __getitem__(self, item):

        print(self.__dict__[item])

    def __setitem__(self, key, value):

        self.__dict__[key]=value

    def __delitem__(self, key):

        print('del obj[key]时,我执行')

        self.__dict__.pop(key)

    def __delattr__(self, item):

        print('del obj.key时,我执行')

        self.__dict__.pop(item)

f1=Foo('sb')

f1['age']=18

print(f1.__dict__)

>>

{'name': 'sb', 'age': 18}

f1['name']='alex'  #设置对象的name

print(f1.__dict__)

>>

{'name': 'alex'}

del f1.name

print(f1.__dict__)

>>

del obj.key时,我执行

{}