1. 作用

把函数变成属性，同时可以对属性进行检查

2. 操作

# property
# getter, setter

# 设定属性
# 一般情况
# class Student(object):

#     def __init__(self, name, score):
#         self.__name = name  # __value 私有变量
#         self.__score = score # 不要在外部访问，don't do that

#     def get_name(self):
#         return self.__name

#     def get_score(self):
#         return self.__score

#     def set_score(self, value):
#         if not isinstance(value, int):
#             raise ValueError('score must be an integer!')
#         if value < 0 or value > 100:
#             raise ValueError('score must between 0 ~ 100')
#         self.__score = value

# s = Student('Tommy', 76)
# print('{}-{}'.format(s.get_name(), s.get_score()))
# s.set_score(90)
# print('{}-{}'.format(s.get_name(), s.get_score()))

# 加上property
# score()方法变成属性

class Student(object):
    def __init__(self, name, score):
        self.__name = name
        self.__score = score

    @property
    def name(self):
        return self.__name

    @property
    def score(self):
        return self.__score
    
    @score.setter
    def score(self, value):
        if not isinstance(value, int):
            raise ValueError('score must be an integer')
        if value < 0 or value > 100:
            raise ValueError('score must between 0 ~ 100')
        self.__score = value

s = Student('Tommy', 76)
print('{}-{}'.format(s.name, s.score))
s.score = 90
print('{}-{}'.format(s.name, s.score))
# s.name = 'Laura' 只读属性