1 #!/usr/bin/env python 2 class Mapper: 3     __mapper_relation = {}#__私有化,其他类不能访问 4  5     @staticmethod 6     def register(cls,value): 7         Mapper.__mapper_relation[cls] = value 8  9     @staticmethod10     def exist(cls):11         if cls in Mapper.__mapper_relation:12             return True13         return False14     @staticmethod15     def value(cls):16         return Mapper.__mapper_relation[cls]17 18 class MyType(type):19 20     def __call__(cls, *args, **kwargs):21         obj = cls.__new__(cls, *args, **kwargs)22         arg_list = list(args)23         if Mapper.exist(cls):24             value =http://www.mamicode.com/ Mapper.value(cls)25             arg_list.append(value)26         obj.__init__(*arg_list,**kwargs)27         return obj28 class Foo(metaclass=MyType):29 30     def __init__(self, name):31         self.name = name32 33     def f1(self):34         print(self.name)35 36 class Bar(metaclass=MyType):37     def __init__(self, name):38         self.name = name39 40     def f1(self):41         print(self.name)42 Mapper.register(Foo,‘666‘)43 Mapper.register(Bar,‘999‘)44 a = Foo()45 b= Bar()46 print(a.name)47 print(b.name)