python @property

class Person(object):
    def __init__(self, age):
        self.age = age

    @property
    def age(self):
        print('i am the get age of Person ...')
        return self._age

    @age.setter
    def age(self, value):
        print('i am the set age of Person ...')
        if value > 18:
            raise ValueError('should under 18')
        self._age = value


class Student(Person):
    @property
    def age(self):
        print('i am the get age of Student ...')
        # 在子类中调用父类的方法
        return super().age

    @age.setter
    def age(self, value):
        print('i am the set age of Student ...')
        # print(Student.__mro__)
        # 在子类中调用父类的方法
        super(Student, Student).age.__set__(self, value)


p = Person(18)
print(p.age)

s = Student(12)
print(s.age)


# property定义只读属性
class A(object):
    def __init__(self):
        super().__init__()

    @property
    def name(self):
        return 'aaa'

a = A()
# 会报错
a.name = 'fffff'
print(a.name)