item内置函数

 1 class Foo:
 2     def __getitem__(self, item):
 3         print('getitem')
 4         return self.__dict__[item]
 5 
 6     def __setitem__(self, key, value):
 7         self.__dict__[key] = value
 8 
 9     def __delitem__(self, key):
10         print('delitem')
11         del self.__dict__[key]
12 
13     pass
14 
15 
16 f1 = Foo()
17 f1[1] = 3
18 print(f1.__dict__)
19 f1['age'] = 27
20 f1['name'] = '小白'
21 del f1['name']
22 print(f1.__dict__)
23 输出：
24 {1: 3}
25 delitem
26 {1: 3, 'age': 27}

该方法同__getattr__内置方法一样