学生成绩信息管理系统

#_author:来童星
#date:2020/4/17
import re
import os
def menu():
    print(
        """
        |----------学生信息管理系统----------|
        |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
        |8.退出系统
        |-----------------------------------|
        |说明：通过数字或者↑↓来选择菜单
        """
    )
def save(student):
    try:
        student_txt=open("student.txt","a")
    except Exception as e:
        student_txt=open("student.txt","w")
    for s in student:
        student_txt.write(str(s)+"
")
    student_txt.close()

def insert():
    student_list=[]
    mark=True
    while mark:
        id=input("请输入ID（如：1001）：")
        if not id:
            break
        name=input("请输入名字：")
        if not name:
            break
        try:
            english=int(input("请输入英语成绩："))
            py=int(input("请输入python成绩："))
            c=int(input("请输入C语言成绩："))
        except:
            print('输入无效，不是整数类型，请重新输入')
            continue
        #将输入的学生信息保存到字典
        student={"id":id,"name":name,"english":english,"python":py,"C语言":c}
        student_list.append(student)
        inputcont=input("是否继续添加：（y/n）")
        if inputcont=="y":
            mark=True
        else:
            mark=False
    save(student_list)#将学生信息保存到文件
    print("学生信息录入完毕!")



def show_student(query):
    if not query:
        print("@__无数据信息__@")
        return
    format_title="{:^6}{:^12}	{:^8}	{:^10}	{:^10}	{:^10}"
    print(format_title.format("ID","名字","英语成绩","python成绩","C语言成绩","总成绩"))

    format_data="{:^6}{:^12}	{:^12}	{:^12}	{:^12}	{:^12}"
    for info in query:
        print(format_data.format(info.get('id',0),info.get('name',0),str(info.get('english',0)),str(info.get('python',0)),str(info.get('C语言',0)),str(info.get('english',0)+info.get('py',0)+info.get('c',0)).center(12)))

def search():
    mark=True
    student_query=[]
    while mark:
        id=""
        name=""
        if os.path.exists('student.txt'):
            mode=input("按ID查找输入1，按姓名查找输入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("student.txt","r") as rfile:
                student=rfile.readlines()
                for list in student:
                    d=dict(eval(list))
                    if id is not "":#判断是否按照id查询
                        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()#清空列表
                inputsearch=input("是否继续查找(y/n)")
                if inputsearch=="y":
                    search()
                else:
                    mark=False
　　　　　　　　　　　　return
        else:
            print("暂未保存数据信息")
            return



def delete():
    mark=True
    while mark:
        studentId=input("请输入需要删除的学生ID:")
        if studentId is not "":
            if os.path.exists("student.txt"):
                with open("student.txt","r") as rfile:
                    stu_old_news=rfile.readlines()
            else:
                stu_old_news=[]
            flag_del=False
            if stu_old_news:  #如果存在学生信息
                with open("student.txt","w") as wfile:
                    d={}
                    for list in stu_old_news:
                        d=dict(eval(list))#字符串转字典
                        if d["id"]!=studentId:
                            wfile.write(str(d)+"
")
                        else:
                            flag_del=False #标记已经删除,前面已经都出来了，此处不做操作就代表删除
                            if flag_del:
                                print("ID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()
            inputdel=input("是否继续删除:(y/n)")
            if inputdel=="y":
                delete()
            else:
                mark=False
def modify():
    show()
    if os.path.exists("student.txt"):
        with open("student.txt","r") as rfile:
            stu_old_news=rfile.readlines()
    else:
        return
    studentId=input("请输入修改的学生ID：")
    with open("student.txt","w") as wfile:
        for s in stu_old_news:
            d=dict(eval(s))
            if d["id"]==studentId:
                print("找到了这名学生，可以修改他的信息")
                while True:
                    try:
                        d['name']=input("请输入名字：")
                        d['english']=int(input("请输入英语成绩："))
                        d['python']=int(input("请输入python成绩："))
                        d['C语言']=int(input("请输入C语言成绩："))
                    except:
                        print("你的输入有误，请重新输入")
                    else:
                        break

                student=str(d)
                wfile.write(student+"
")  #将已经修改的信息写入到文件
                print("修改成功")
            else:
                wfile.write(student)#将未修改的信息写入到文件
    inputmod=input("是否继续修改其他学生信息？(y/n)")
    if inputmod=="y":
        modify()



def sort():
    show()
    if os.path.exists("student.txt"):
        with open("student.txt","r") as rfile:
            student_old=rfile.readlines()
            student_news=[]
        for list in student_old:
            d=dict(eval(list))
            student_news.append(d)
    else:
        return
    ascORdesc=input("请选择：(0:升序；1:降序)")
    if ascORdesc=="0":
        ascORdescbool=False
    elif ascORdesc=="1":
        ascORdescbool=True
    else:
        print("您的输入有误，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；4.按总成绩排序")
    if mode=="1":
        student_news.sort(key=lambda x:x['english'],reverse=ascORdescbool)
    elif mode=="2":
        student_news.sort(key=lambda x:x['python'],reverse=ascORdescbool)
    elif mode=="3":
        student_news.sort(key=lambda x:x['C语言'],reverse=ascORdescbool)
    elif mode=="4":
        student_news.sort(key=lambda x:x['english']+x['python']+x['C语言'],reverse=ascORdescbool)
    else:
        print("您的输入有误，请重新输入")
        sort()
    show_student(student_news)



def total():
    if os.path.exists("student.txt"):
        with open("student.txt","r") as rfile:
            student_old=rfile.readlines()
            if student_old:
                print("一共有 %s 名学生"%len(student_old))
            else:
                print("还没有录入学生信息")
    else:
        print("暂未保存数据信息")

def show():
    student_news=[]
    if os.path.exists('student.txt'):
        with open("student.txt","r") as rfile:
            student_old=rfile.readlines()
        for list in student_old:
            student_news.append(eval(list)) #将找到的学生信息保存到字典中
        if student_news:
            show_student(student_news)

    else:
        print("暂未保存数据信息")


def main():
    flag=True
    while(flag):
        menu()
        option=input("请选择：")
        option_str=re.sub("D","",option)
        if option 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")
            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()
if __name__=="__main__":
    main()
运行结果如下：