python简单实现学生管理系统

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
# Author:Du Fei
import os

#学号，姓名，年龄，性别，身高
allStudentsList=[]
#从文件中读取数据
def readFromFile(fileName):
    if not os.path.exists(fileName):# 如果文件不存在，则新增一个空文件
        f = open(fileName,"w")
        f.close()
    with open(fileName,"r",encoding="utf-8") as f:
        for onStr in f:
            oneList=onStr.strip("\n").split(",")
            oneList[0]=int(oneList[0])#学号
            oneList[1]=oneList[1]#姓名
            oneList[2]=int(oneList[2])#年龄
            oneList[3]=oneList[3]#性别
            oneList[4]=float(oneList[4])#身高
            allStudentsList.append(oneList)

#将数据写入文件
def writeToFile(fileName):
    f =open(fileName,"w")
    f.close()

    with open(fileName,"a",encoding="utf-8") as f:
        for oneList in allStudentsList:
            oneStr=str(str(oneList[0])+","+oneList[1]+","+str(oneList[2])+","+oneList[3]+","+str(oneList[4])+"\n")
            f.write(oneStr)

#显示所有学生信息
def allStudentsShow():
    for one in allStudentsList:
        print("学号：%d,姓名：%s,年龄：%d,性别：%s,身高：%f" % (one[0], one[1], one[2], one[3],one[4]))

#新增学生
def addNewStudent(newStuList):
    #check学号是否重复复
    for one in allStudentsList:
        if one[0] == newStuList[0]:
            return -1 #学号重复
        allStudentsList.append(newStuList)
        writeToFile("student.txt")
        return 1

#修改学生年龄
def updateStudentsAge(id,newAge):
    for one in allStudentsList:
        if one[0]==id:
            one[2]=newAge
            break
    else:
        return -1#找不到此学号
    writeToFile("student.txt")
    return 1

#删除学生
def deleteStudent(id):
    index =0
    for one in allStudentsList:
        if one[0] ==id:
            del allStudentsList[index]
            break
        index +=1
    else:
        return -1#找不到要删除的学号
    writeToFile("student.txt")
    return 1

#按照姓名查找
def searchStudents(name):
    flag =0
    for one in allStudentsList:
        if one[1]==name:
            print("学号：%d,姓名：%s,年龄：%d,性别：%s,身高：%f" % (one[0], one[1], one[2], one[3], one[4]))
            flag=1
    if flag==0:
        return -1#查无此人
    return 1


def sortMe(oneList):
    return oneList[0]

#按序号排序
def orderById(flag):#flag:1升序，2降序
    if flag==1:#升序
        allStudentsList.sort(reverse=False,key=lambda oneList:oneList[0])
    else:
        allStudentsList.sort(reverse=True,key=sortMe)

#功能菜单
def menuShow():
    print("**********************************")
    print("*1.查看所有学生信息****************")
    print("*2.新增学生************************")
    print("*3.修改学生************************")
    print("*4.删除学生************************")
    print("*5.按姓名查找**********************")
    print("*6.按学号排序**********************")
    print("*7.保存***************************")
    print("*8.退出***************************")
    print("**********************************")


if __name__ == "__main__":
    #从文件中读取数据
    readFromFile("student.txt")
    # print(allStudentsList)
    while True:
        # 显示主菜单
        menuShow()
        select =int(input("请选择功能选项："))
        if select == 1:
            allStudentsShow()
        elif select == 2:
            while True:
                try:
                    id = int(input("请输入学号："))
                    name = input("请输入姓名：")
                    age = int(input("请输入年龄："))
                    sex = input("请输入性别：")
                    height = float(input("请输入身高："))

                    newStuList=[id,name,age,sex,height]
                    if addNewStudent(newStuList) ==-1:
                        print("学号已存在,请重新输入")
                    else:
                        flag=input("新增用户成功,是否继续新增(y/n)?:")
                        if flag.lower() !="y":
                            break
                except:
                    print("输入有误请重新输入")

        elif select == 3:
            while True:
                id=int(input("请输入序号："))
                newAge=int(input("请输入新的年龄："))
                if updateStudentsAge(id,newAge) ==-1:
                    print("找不到此学号的学生，请重新输入")
                else:
                    flag = input("修改成功,是否继续修改(y/n)?:")
                    if flag.lower() != "y":
                        break

        elif select == 4:
            while True:
                id =int(input("请输入删除的学号："))
                if deleteStudent(id) == -1:
                    print("找不到此学号的学生，请重新输入")
                else:
                    flag = input("删除成功,是否继续删除(y/n)?:")
                    if flag.lower() != "y":
                        break
        elif select == 5:
            while True:
                name=input("请输入查找的姓名：")
                if searchStudents(name) ==-1:
                    print("查无此人")

                flag = input("是否继续查找(y/n)?:")
                if flag.lower() != "y":
                    break

        elif select == 6:
            flag=int(input("请选择排序方式（1：升序，2：降序）"))
            orderById(flag)
            allStudentsShow()
        elif select == 7:
            writeToFile("student.txt")
        else:
            exit()