请问大家以下代码哪里错了？提交后一直不行

class Person(object):

    def __init__(self, name, gender):

        self.name = name

        self.gender = gender

class Student(Person):

    def __init__(self, name, gender, score):

        super(Student, self).__init__(name, gender)

        self.score = score

    def __str__(self):

        return 'Student:%s,%s,%d'%(self.name,self.gender,self.score)

        __repr__ = __str__

s = Student('Bob', 'male', 88)

print s