class Student(object):
    def __init__(self, name, score, gender):
        if isinstance(name, str):
            self.name = name
        if gender == '男' or gender == '女':
            self.__gender = gender
        if isinstance(score, int):
            self.score = score

    def get_gender(self):
        return self.__gender

    def set_gender(self, gender):
        if gender == '男' or gender == '女':
            self.__gender = gender
            a = '性别设置成功为%s ' % self.__gender
            return a
        else:
            a = '性别输入错误'            return a

    def pr_s(self):
        na_sc = '%s %s' % (self.name, self.score)
        return na_sc

    def get_greet(self):
        if self.score > 80:
            A = '评价为 A '            return self.name, A
        elif self.score > 60:
            B = '评价为 B '            return self.name, B
        else:
            C = '评价为 C '            return self.name, C