描述符——类型检测，待补充……

先看代码：

# 描述的类
class Check(object):
    def __init__(self, key, value_type):
        self.k = key
        self.t = value_type

    def __set__(self, instance, value):
        print('set方法...')
        if isinstance(value, self.t):
            instance.__dict__[self.k] = value
        else:
            raise TypeError('传入格式错误！')

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

    def __delete__(self, instance, owner):
        print('delete方法...')
        return instance.__dict__.pop(self.k)


class C(object):
    name = Check('name', str)
    age = Check('age', int)

    def __init__(self, name, age):
        self.name = name
        self.age = age

c1 = C('aa',12)
c1.name='cname'
print(c1.name)