property1.py

#!/usr/bin/env python3
# -*- coding:utf-8 -*-
# github:https://github.com/tangthis

#Python内置的@property装饰器就是负责把一个方法变成属性调用的
class Student(object):
	@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

#@property的实现比较复杂，我们先考察如何使用。把一个getter方法变成属性，只需要加上@property就可以了，此时，@property本身又创建了另一个装饰器@score.setter，负责把一个setter方法变成属性赋值

s = Student()
s.score = 60
print(s.score)

class Student(object):

    @property
    def birth(self):
        return self._birth

    @birth.setter
    def birth(self, value):
        self._birth = value

    @property
    def age(self):
        return 2015 - self._birth

s = Student()
s.birth = 2000
#s.age = 20
print(s.age)