python实现学生成绩测评系统

import os
def printwindows():
 print('='*30)
 print('学生信息管理系统V1.0')
 print('1.添加学生信息')
 print('2.删除学生信息')
 print('3.修改学生信息')
 print('4.显示所有学生信息')
 print('5.保存数据')
 print('0.退出系统')
 print('='*30)
students = []
def add_student():
 while 1:
 os.system("cls")
 student = []
 student_name = input("请输入学生姓名：")
 student_id = input("请输入学生学号：")
 student_xingbie = input("请输入学生性别：")
 student_age = input("请输入学生年龄：")
 student_pione = input("请输入学生电话：")
 student.append(student_name)
 student.append(student_id)
 student.append(student_xingbie)
 student.append(student_age)
 student.append(student_pione)
 students.append(student)
 n = input("是否继续添加？y or n:")
 if n == "n":
  break
def del_student():
 while 1:
 del_student_id = input("请输入要删除的学生学号：")
 for student in students:
  if student[1] == del_student_id:
  del student
  print("删除成功！")
  break
 n = input("是否继续添加？y or n:")
 if n == "n":
  break
def updata_student():
 while 1:
 updata_student_id = input("请输入你要更改的学生学号：")
 for student in students:
  if student[1] == updata_student_id:
  flag = input("选择你要更改的学生信息：1.姓名，2.学号，3.性别，4.年龄，5.电话:")
  if flag == 1:
   name = input("请输入你要换成的名字：")
   student[0] = name
  elif flag == 2:
   student_id = input("请输入你要换成的学号：")
   student[1] = student_id
  elif flag == 3:
   student_xinbie = input("请输入你要换成的性别:")
   student[2] = student_xinbie
  elif flag == 4:
   student_age = input("请输入你要换成的年龄：")
   student[3] = student_age
  elif flag == 5:
   student_pione = input("请输入你要换成的电话:")
   student[4] = student_pione
  else :
   pass 
 n = input("是否继续添加？y or n:")
 if n == "n":
  break
def show_student():
 print(" 学生信息")
 print("姓名 学号 性别 年龄 电话")
 for student in students:
 print(student[0] + " " + student[1] + " " + student[2] + " " + student[3] + " " + student[4])
 os.system("pause") 
def read_in_file():
 with open("student_data.txt", 'a') as f:
 for student in students:
  f.write(student[0] + " " + student[1] + " " + student[2] + " " + student[3] + " " + student[4] + '\n')
 print("保存成功！")
def main():
 while(1):
 os.system("cls")
 printwindows()
 print("请输入你要执行的代码：")
 n = int(input())
 if n == 1:
  add_student()
 elif n == 2:
  del_student()
 elif n == 3:
  updata_student()
 elif n == 4:
  show_student()
 elif n == 5:
  read_in_file()
 else:
  break
if __name__ == '__main__':
 main()