class Foo:
    def __init__(self,name):
        self.name=name

    def __getitem__(self, item):
        print(self.__dict__[item])

    def __setitem__(self, key, value):
        print(‘obj[key]= vlaue時我執行‘)
        self.__dict__[key]=value


    def __delitem__(self, key):
        print(‘del obj[key]時,我執行
 
‘)
        self.__dict__.pop(key)


    def __delattr__(self, item):
        print(‘del obj.key時,我執行‘)
        self.__dict__.pop(item)



f1=Foo(‘sb‘)

f1[‘age‘]=18

f1[‘age1‘]=19

del f1.age1

del f1[‘age‘]

f1[‘name‘]=‘alex‘

print(f1.__dict__)

python 中的__item__方法