python学生管理系统

import os
import re

#获取本机用户名，构建student.txt文件名创建在左面
import getpass
username=getpass.getuser()
print("当前登录用户名"+username)
filename="student.txt"
filename="C:\\Users\\"+username+"\\Desktop"+"\\"+filename
print(filename)
def main():
    ctrl=True
    while ctrl:
        menu()
        option=input("请选择>>>:")
        option_str=re.sub("\D","",option)
        if option_str in ["0","1","2","3","4","5","6","7"]:
            option_int=int(option_str)
            if option_int==0:
                print("你已经退出学生管理系统")
                ctrl=0
            elif option_int==1:
                insert()
            elif option_int==2:
                search()
            elif option_int==3:
                delete()
            elif option_int==4:
                modify()
            elif option_int==5:
                sort()
            elif option_int==6:
                total()
            elif option_int==7:
                show()

def menu():     #first page
    print(
    """
                学生信息管理系统

     ===============功能菜单===============
    |                                     
    |   1 录入学生信息                     
    |   2 查找学生信息                     
    |   3 删除学生信息                     
    |   4 修改学生信息                     
    |   5 排序                            
    |   6 统计学生总人数                   
    |   7 显示所有学生信息                 
    |   0 退出管理系统                      
    =======================================
    说明：通过数字或↑↓方向键选择菜单  
    """
    )
def insert():   #录入学生信息
    studentlist=[]
    mark=True
    while mark:
        id=input("请输入id如（1001）:")
        if not id:
            break
        name=input("请输入姓名")
        if not name:
            break
        try:
            english =int(input("请输入英语成绩"))
            python  = int(input("请输入python成绩"))
            c       = int(input("请输入c语言成绩"))
        except:
            print("输入成绩格式无效")
            continue
        student={"id":id,"name":name,"english":english,"python":python,"c":c}
        studentlist.append(student)
        inputmark=input("是否继续添加(Y/N):")
        if inputmark=="Y" or inputmark=="y":
            mark=1
        else:
            mark=0
    print(studentlist)
    save(studentlist)
    print("学生信息录入完毕")

def search():
    mark=True
    student_query=[]
    while mark:
        id=""
        name=""
        if os.path.exists(filename):
            mode=input("按id查询输入1；按姓名查询输入2：")
            if mode=="1":
                id=input("请输入学生id:")
            elif mode=="2":
                name=input("请输入学生姓名")
            else:
                print("你的输入有误,请重新输入")
                search()
            with open(filename,"r") as file:
                student=file.readlines()
                for list in student:
                    d=dict(eval(list))
                    if id is not "":
                        if d["id"]==id:
                            student_query.append(d)
                    elif name is not "":
                        if d["name"]==name:
                            student_query.append(d)
                show_student(student_query)
                student_query.clear()
                inputmark=input("是否继续查询（y/n）：")
                if inputmark =="y" or inputmark=="Y":
                    mark=True
                else:
                    mark=False
        else:
            print("暂未保存数据信息")
            return
def delete():
    mark=True
    while mark:
        studentid=input("请输入你要删除的学生id,如果输入为空则退出删除")
        if studentid=="":
            return 1
        if studentid is not "":     #此处判断输入是否为空，如果输入有效执行读取信息
            if os.path.exists(filename):
                with open(filename,"r") as rfile:
                    student_old=rfile.readlines()
            else:   #如过为获取到文件内容，则返回空列表。stuent_ol=[]=false
                student_old=[]
            ifdel=False
            if student_old:
                with open(filename,"w") as wfile:
                    d={}
                    for list in student_old:
                        d=dict(eval(list))
                        if d['id']!=studentid:
                            wfile.write(str(d)+"\n")
                            #此处相当于读取了所有学生信息，除了id为输入要删除的id以外，其他学生的信息全部重新写入
                        else:   #如果 d['id']!=studentid ,那么ifdel=true,没有写入证明删除成功
                            ifdel=True
                    if ifdel:
                        print("id号为%s的学生信息已经删除"%studentid)
                    else:
                        print("没有找到id为%s的学生信息"%studentid)
            else:
                print("无学生信息")
                break
            show()
            inputmark=input("是否继续删除(Y/N):")
            if inputmark=="y" or inputmark=='Y':
                mark=True
            else:
                mark=False
def modify():
    show()
    if os.path.exists(filename):
        with open(filename,"r") as rfile:
            student_old=rfile.readlines()

    else:
        return
    studentid=input("请输入你要修改的学生信息的id：")
    with open(filename,"w") as wfile:
        for student in student_old:
            d=dict(eval(student))
            if d['id']==studentid:
                print("找到该学生id，可以修改信息")
                while 1:
                    try:
                        d["name"]=input("请输入姓名")
                        d["english"] =int( input("请输入英语成绩"))
                        d["python"] = int(input("请输入python成绩"))
                        d["c"] = int(input("请输入C语言成绩"))
                    except:
                        print("输入信息有误,请重新输入")
                    else:
                        break
                student=str(d)
                wfile.write(student+"\n")   #修改后的信息写入文件
                print("信息修改成功")
            else:
                wfile.write(student)    #未修改的内容重新写入
    mark = input("是否继续修改（Y/N）：")
    if mark == "y" or mark == "Y":
        modify()
    else:
        return 1

def sort():
    show()  #首先显示全部学生信息
    if os.path.exists(filename):
        with open(filename,"r") as file:
            student_old=file.readlines()
            student_new=[]
        for list in student_old:
            d=dict(eval(list))
            student_new.append(d)       #一个列表中的元素为字典，每个元素存储每个学生信息的字典
    else:
        return
    ascordesc=input("请选择（0升序 / 1降序）：")
    if ascordesc=="0":
        ascbool=False
    if ascordesc=="1":
        ascbool=True
    else:
        print("你的输入有误，请重新输入")
        sort()
    mode=input("""请选择排序方式（1 按英语成绩排序 2 按python成绩排序 3 按c语言成绩排序 0 按总成绩排序   ）""")
    if mode=="1":
        student_new.sort(key=lambda x:x["english"],reverse=ascbool)
    elif mode=="2":
        student_new.sort(key=lambda x:x["python"],reverse=ascbool)
    elif mode=="3":
        student_new.sort(key=lambda x:x["c"],reverse=ascbool)
    elif mode=="0":
        student_new.sort(key=lambda x: x["english"]+x["python"]+x["c"], reverse=ascbool)
    else:
        print("输入有误，请重新输入")
        sort()
    show_student(student_new)

def total():
    if os.path.exists(filename):
        with open(filename,"r") as rfile:
            student_old=rfile.readlines()
            if student_old:
                print("一共有%d名学生"%len(student_old))
            else:
                print("还没有录入学生信息")
    else:
        print("暂时未保存数据信息")
def show():
    student_new=[]
    if os.path.exists(filename):
        with open(filename,"r") as rfile:
            student_old=rfile.readlines()
        for list in student_old:
            student_new.append(eval(list))
        if student_new:
            show_student(student_new)
    else:
        print("暂未找到数据信息")
def save(student):
    try:
        students_txt=open(filename,"a")
    except Exception as e:
        students_txt=open(filename,"w")
    for info in student:
        students_txt.write(str(info)+"\n")
    students_txt.close()
def show_student(studentList):
    if not studentList:
        print("!!--无数据信息--!!\n")
        return
    format_title="{:^6}{:^12}\t{:^8}\t{:^10}\t{:^10}\t{:^10}"
    print(format_title.format("id","姓名","英语成绩","python成绩","语言成绩","总成绩"))
    format_data="{:^6}{:^12}\t{:^12}\t{:^12}\t{:^12}\t{:^12}"
    for info in studentList:
        print(format_data.format(info.get("id"),info.get("name"),str(info.get("english")),
                                 str(info.get("python")),str(info.get("c")),
                                 str(info.get("english")+info.get("c")+info.get("python")).center(12)
                                 ))
main()