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()