我是小白，程序报错，请前辈们看一下，谢谢！

代码:

class StudentModel:
    def __init__(self, n01=0, name="", age=0, score=0):
        self.n01 = n01
        self.name = name
        self.age = age
        self.score = score


class StudentManagerController:
    __init_n01 = 1000

    def __init__(self):
        self.__stu_list = []

    @property
    def stu_list(self):
        return self.__stu_list

    def add_student(self, stu_info):
        stu_info.n01 = self.__generate_n01()

        self.__stu_list.append(stu_info)

    def __generate_n01(self):
        StudentManagerController.__init_n01 += 1
        return StudentManagerController.__init_n01

    def remove_student(self, n01):
        for item in self.__stu_list:
            if item.n01 == n01:
                self.__stu_list.remove(item)
                return True
        return False

    def update_student(self, str_info):
        for item in self.__stu_list:
            if item.n01 == str_info.n01:
                item.name = stu_info.name
                item.age = stu_info.age
                item.score = stu_info.score
                return True
        return False


class StudentManagerView:
    def __init__(self):
        self.__manager = StudentManagerController()

    def __display_menu(self):
        print("1)添加学生")
        print("2)显示学生")
        print("3)删除学生")
        print("4)修改学生")
        print("5)按照成绩升序显示学生")

    def __select_menu(self):
        item = input("请输入：")
        if item == "1":
            self.__input_student()
        elif item == "2":
            self.__output_student(self.__manager.stu_list)
        elif item == "3":
            pass
        elif item == "4":
            pass
        elif item == "5":
            pass

    def main(self):
        while True:
            self.__display_menu()
            self.__select_menu()

    def __input_student(self):
        name = input("请输入姓名：")
        age = int(input("请输入年龄："))
        score = int(input("请输入成绩："))
        stu = StudentModel(n01, name, age, score)
        self.__manager.add_student(stu)

    def __output_student(self, list_output):
        for item in list_output:
            print(item.id, item.name, item.age, item.score)


view = StudentManagerView()
view.main()

报错代码：

1)添加学生
2)显示学生
3)删除学生
4)修改学生
5)按照成绩升序显示学生
请输入：1
请输入姓名：qtx
请输入年龄：45
请输入成绩：78
Traceback (most recent call last):
File “D:\python\项目\学生管理系统.py”, line 87, in
view.main()
File “D:\python\项目\学生管理系统.py”, line 72, in main
self.select_menu()
File “D:\python\项目\学生管理系统.py”, line 59, in __select_menu
self.input_student()
File “D:\python\项目\学生管理系统.py”, line 78, in __input_student
stu = StudentModel(n01, name, age, score)
^^^
NameError: name ‘n01’ is not defined

进程已结束,退出代码1

需求：

    请前辈们指点一下报错原因和解决方法，谢谢！