class Course:
    name = ' '
    credit = ' '

    def __init__(self, name, credit):
        Course.name = name
        Course.credit = credit
        print("课程名：" + Course.name + " 课程学分：" + Course.credit)

    def _reset_course(self, name, credit):
        Course.name = name
        Course.credit = credit
        print("课程名：" + Course.name + " 课程学分：" + Course.credit)


class InformationSecurity(Course):
    number_of_people = ' '
    teacher = ' '

    def _set_IS(self, number_of_people, teacher):
        InformationSecurity.number_of_people = number_of_people
        InformationSecurity.teacher = teacher
        print(InformationSecurity.name + " 为" + InformationSecurity.credit + "学分课程，由"
              + InformationSecurity.teacher + "授课，课堂人数为" + InformationSecurity.number_of_people)

    def _reset_course(self, name, credit, number_of_people, teacher):
        InformationSecurity.name = name
        InformationSecurity.credit = credit
        InformationSecurity.number_of_people = number_of_people
        InformationSecurity.teacher = teacher
        print(InformationSecurity.name + " 为" + InformationSecurity.credit + "学分课程，由"
              + InformationSecurity.teacher + "授课，课堂人数为" + InformationSecurity.number_of_people)


cipher = Course("密码学", "4")
cipher._reset_course("密码分析学", "4")

Is1 = InformationSecurity("信息安全", "4")
Is1._set_IS("70", "张三")
Is1._reset_course("信息安全攻击","8","30","李四")