class C(object):

    def __init__(self):

        self._x = None

    def getx(self):

        print('get')

        return self._x

    def setx(self, value):

        print('set')

        self._x = value

    def delx(self):

        print('del')

        del self._x

    x = property(getx, setx, delx, "I'm the 'x' property.")

# c = C()

# c.x = 12

# print(c.x)

# del c.x

# @property 装饰器负责把一个方法变成属性调用

class Student(object):

    # 把一个getter方法变成属性，只需加上 @property

    @property

    def score(self):

        return self._score

    # 把一个setter方法变成属性，@fun.setter

    @score.setter

    def score(self, value):

        if not isinstance(value, int):

            raise ValueError('score must be an interger!')

        if value < 0 or value > 100:

            raise  ValueError('score must between 0~100')

        self._score = value

s = Student()

s.score = 60

print(s.score)

class Parrot(object):

    def __init__(self):

        self._voltage = 100000

    @property

    def voltage(self):

        """Get the current voltage."""

        return self._voltage

    # setter,deleter，这些额外函数名和property相同

    @voltage.setter

    def voltage(self, value):

        self._voltage = value

    @voltage.deleter

    def voltage(self):

        del self._voltage