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)    def __delattr__(self, item):        print('del obj.key')        self.__dict__.pop(item)f1 = Foo('sb')f1['age']=18f1['age1']=19# del f1.age1del f1['age']f1['name']='alex'print(f1.__dict__)