class Another_Student():

    def __init__(self,name,gender):

        self.name = name

        self.__gender = gender

    def get_gender(self):

        return self.__gender

    def set_gender(self,gender):

        self.__gender = gender

        return self.__gender

bart = Another_Student('Bart', 'male')

if bart.get_gender() != 'male':

    print('测试失败!')

else:

    bart.set_gender('female')

    if bart.get_gender() != 'female':

        print('测试失败!')

    else:

        print('测试成功!')