这段代码运行错误是什么原因，明明和提示答案写的一样
class Person(object):
__slots__ = ('name', 'gender')
def __init__(self, name, gender):
self.name = name
self.gender = gender
class Student(Person):
__slots__ = （'score',）
def __init__(self，name,gender,score):
super(Student,self).__init__(name,gender)
self.score=score
s = Student('Bob', 'male',99)
s.name = 'Tim'
s.score = 99
print s.score
