#coding:utf-8
class Student(object):

	def __init__(self,name,score):
		
		self.name = name
		self.__score = score

	@property
	def score(self):
		return self.__score

	@score.setter
	def score(self,score):
		if score < 0 or score > 100:
			raise ValueError('invalid score')
		self.__score = score


s = Student('Bob', 59)
s.score = 10
print s.score

