类的装饰器应用

class Type:
    def __init__(self, key, expcet_type):
        self.key = key
        self.expct_type = expcet_type

    def __get__(self, instance, owner):
        print('执行get')
        return instance.__dict__[self.key]

    def __set__(self, instance, value):
        print('执行set')
        if not isinstance(self.key, self.expct_type):
            print('%s 类型不符合%s'%(value,self.expct_type))
            return
        instance.__dict__[self.key] = value


def test(**kwargs):
    def wrapper(obj):
        for k, v in kwargs.items():
            val = Type(k, v)
            setattr(obj, k, val)
        return obj

    return wrapper


@test(name=str, age=int, gender=str, price=int)
class Foo:
    def __init__(self, name, age, gender, price):
        self.name = name
        self.age = age
        self.gender = gender
        self.price = price


print(Foo.__dict__)
f1 = Foo('alex',16, '男',13)
print(f1.__dict__)
输出：
{'__module__': '__main__', '__init__': <function Foo.__init__ at 0x009A8A00>, '__dict__': <attribute '__dict__' of 'Foo' objects>, '__weakref__': <attribute '__weakref__' of 'Foo' objects>, '__doc__': None, 'name': <__main__.Type object at 0x00992FD0>, 'age': <__main__.Type object at 0x009AE148>, 'gender': <__main__.Type object at 0x009AE0E8>, 'price': <__main__.Type object at 0x009AE178>}
执行set
执行set
16 类型不符合<class 'int'>
执行set
执行set
13 类型不符合<class 'int'>
{'name': 'alex', 'gender': '男'}