学生管理系统含保存功能（需改进）

def showinfo():
    print('*'*20)
    print('***1: 添加学生')
    print('***2: 删除学生')
    print('***3: 查找学生')
    print('***4: 修改学生')
    print('***5: 查看全部学生信息')
    print('***6: 退出')

def getusers():
    users.clear()
    fp=open('information.txt','r+')
    list1 = fp.readlines()
    fp.close()
    list2=[]
    for list3 in list1:
        list2.append(list3.split())
    ketlist = ["name","pass"]
    for valuelist in list2:
        user = dict(zip(ketlist,valuelist))
        users.append(user)
        
students=[]
users=[]
first_add=1
fp =open('information.txt','a+')
fp.close()
        
while 1:
    getusers()
    x = input('用户未登录\n 登入请输入0 注册请输入1:\n')
    if x== '1':
        fp=open('infomation.txt','a+')
        user_name = input('请输入注册账号：')
        user_pass = input('请输入注册密码：')
        user_info = {'name':user_name,'pass':user_pass}
        i=0
        for user in users:
            if user==user_info:
                i+=1
        if i>0 :
            print('用户已存在，请登入')
            continue
        else:
            print(user_name,user_pass,file = fp)
            fp.close()
            print('注册成功')
            continue
    if x == '0':
        user_name = input('请输入账号：')
        user_pass = input('请输入密码：')
        user_info = {'name':user_name,'pass':user_pass}
        i=0
        for user in users:
            if user==user_info:
                i+=1
        if i>0 :
            print('登入成功!')
            break
        else:
            print('账号密码错误')
            continue
while 1:
    showinfo()
    key = input('（请输入所需操作对应的数字）')
    
    if key == '1':
        print("添加学生信息：")
        stuName = input("请输入学生姓名：")
        stuId = input("请输入学生学号(学号不可重复)：")
        stuClass = input("请输入学生班级:")
        #验证学号是否唯一
        i = 0
        leap = 0
        for stu in students:
            if stu['stuId'] == stuId:
                leap = 1
                break
            else:
                i = i + 1
        if leap == 1:
            print("输入学生学号重复，添加失败！")
        else:
            # 定义一个字典，存放单个学生信息
            stuInfo = {}
            stuInfo['stuName'] = stuName
            stuInfo['stuId'] = stuId
            stuInfo['stuClass'] = stuClass
            # 单个学生信息放入列表
            students.append(stuInfo)
            print("添加成功！")
    elif key == '2':
        print("准备删除学生信息：")
        delId=input("请输入要删除的学生学号:")
        #i记录要删除的下标，leap为标志位，如果找到leap=1，否则为0
        i = 0
        leap = 0
        for stu in students:
            if stu['stuId'] == delId:
                leap = 1
                break
            else:
                i=i+1
        if leap == 0:
            print("没有此学生学号，删除失败！")
        else:
            del students[i]
            print("删除成功！")

    elif key == '3':
        print("正在修改学生信息：")
        alterId=input("请输入你要修改学生的学号:")
        #检测是否有此学号，然后进行修改信息
        i = 0
        leap = 0
        for stu in students:
            if stu['stuId'] == alterId:
                leap = 1
                break
            else:
                i = i + 1
        if leap == 1:
            while True:
                alterNum=int(input(" 1.修改学号\n 2.修改姓名 \n 3.修改班级 \n 4.退出修改\n"))
                if alterNum == 1:
                    newId=input("输入更改后的学号:")
                    #修改后的学号要验证是否唯一
                    i = 0
                    leap1 = 0
                    for stu1 in students:
                        if stu1['stuId'] == newId:
                            leap1 = 1
                            break
                        else:
                            i = i + 1
                    if leap1 == 1:
                        print("输入学号不可重复，修改失败！")
                    else:
                        stu['stuId']=newId
                        print("学号修改成功")

                elif alterNum == 2:
                    newName=input("输入更改后的姓名:")
                    stu['stuName'] = newName
                    print("姓名修改成功")

                elif alterNum == 3:
                    newClass=input("输入更改后的班级:")
                    stu['stuClass'] = newClass
                    print("班级修改成功")

                elif alterNum == 4:
                    break
                else:
                    print("输入错误请重新输入")
        else:
            print("没有此学号，修改失败！")

    elif key =='4':
        print("正在查询学生信息：")
        searchID=input("请输入你要查询学生的学号:")
        #验证是否有此学号
        i = 0
        leap = 0
        for stu in students:
            if stu['stuId'] == searchID:
                leap = 1
                break
            else:
                i = i + 1
        if leap == 0:
            print("没有此学生学号，查询失败！")
        else:
            print("找到此学生，信息如下：")
            print("学号：%s\n姓名：%s\n班级：%s\n"%(stu['stuId'],stu['stuName'],stu['stuClass']))

    elif key == 5:
                #遍历并输出所有学生的信息
                print('*'*30)
                print("接下来进行遍历所有的学生信息...")
                print("学 号     姓 名     班 级")
                for stu in students:
                    print("  %s         %s        %s"%(stu['stuId'],stu['stuName'],stu['stuClass']))
                print("*"*30)

    elif key == '6':
        x = input("确认退出（yes或者no）")
        if x == 'yes':
            print("欢迎使用本系统，谢谢")
            break;