Python--简单学生管理系统

import os

filename='student.txt'
def meun():
    print('''==========================学生管理系统=====================
--------------------------功能菜单------------------------''')
    print('\t\t\t\t\t\t1.录入学生信息')
    print('\t\t\t\t\t\t2.查找学生信息')
    print('\t\t\t\t\t\t3.删除学生信息')
    print('\t\t\t\t\t\t4.修改学生信息')
    print('\t\t\t\t\t\t5.排序')
    print('\t\t\t\t\t\t6.统计学生总人数')
    print('\t\t\t\t\t\t7.显示所有学生信息')
    print('\t\t\t\t\t\t8.退出')
def main():
    while True:
        meun()
        choice=int(input('请输入你的选择：'))
        if choice in [1,2,3,4,5,6,7,8]:
            if choice==8:
                answer=input('你确定要退出系统吗')
                if answer=='Y' or answer=='y':
                    print('谢谢你的使用！')
                    break
                else:
                    continue
            elif choice==1:
                insert()
            elif choice==2:
                search()
            elif choice==3:
                delete()
            elif choice==4:
                update()
            elif choice==5:
                sort()
            elif choice==6:
                totol()
            elif choice==7:
                showall()
def insert():
    stu_list=[]
    while True:
        name=input('请输入学生姓名：')
        id=input('请输入学生id:')
        if not id and not name :
            break
        try:
            english=int(input('请输入英语成绩：'))
            python=int(input('请输入python成绩：'))
            java=int(input('请输入java成绩：'))

        except:
            print("输入无效，请输入整数！")
            continue
        #将录入的学生信息保存到字典中
        stu_dict={'id':id,'name':name,'english':english,'python':python,'java':java}
        #将学生信息保存到列表中
        stu_list.append(stu_dict)
        answer=input('是否继续录入？y/Y')
        if answer=='y' or answer=='Y':
            continue
        else:
            break
    save(stu_list)
    print('录入学生信息成功！')
def save(stu_list):
    try:
        stu_txt=open(filename,'a',encoding='utf-8')
    except:
        stu_txt= open(filename, 'w', encoding='utf-8')
    for items in stu_list:
        stu_txt.write(str(items)+'\n')
    stu_txt.close()
def search():
    student_query=[]
    while True:
        id=''
        name=''
        if os.path.exists(filename):
            mode=int(input('按Id查询请输入1，按名字查询请输入2'))
            if mode==1:
                id=input('请输入要查询的ID：')
            elif mode==2:
                name=input('请输入要查询的学生名字：')
            else:
                print('您的输入有误，请重新输入！')
                search()
            with open(filename,'r',encoding='utf=8') as file:
                stu_list=file.readlines()
                for item in stu_list:
                    d=dict(eval(item))
                    if id!='':
                        if d['id']==id:
                            student_query.append(d)
                    elif name!='':
                        if d['name']==name:
                            student_query.append(d)
            #显示查询结果
            show_student(student_query)
            #清空列表
            student_query.clear()
            answer=input('是否继续查询')
            if answer=='y' or answer=='Y':
                continue
            else:
                break
        else:
            print('暂未保存信息')
            return
def show_student(list):
    if len(list)==0:
        print('没有查询到信息')
        return
    #定义标题显示格式
    format_title='{:^6}\t{:^12}\t{:^8}\t{:^10}\t{:^10}\t{:^8}'
    print(format_title.format('ID','姓名','英语','Python','Java','Sum'))
    #内容显示格式
    format_data='{:^6}\t{:^12}\t{:^8}\t{:^10}\t{:^10}\t{:^8}'
    for item in list :
        print(format_data.format(item.get('id'),item.get('name'),item.get('english'),item.get('python'),item.get('java'),item.get('english')+item.get('python')+item.get('java')))
def delete():
    while True:
        stu_id=input('请输入要删除的学生id:')
        if stu_id!='' :
            if os.path.exists(filename):
                with open(filename,'r',encoding='utf-8') as wfile :
                    stu_list=wfile.readlines()
            else:
                stu_list=[]
            flag=False
            if stu_list:
                with open(filename,'w',encoding='utf=8') as wfile:
                    d={}
                    for item in stu_list :
                        d=dict(eval(item))
                        if d['id']!=stu_id:
                            wfile.write(str(d)+'\n')
                        else:
                            flag=True
                    if flag :
                        print('学号为{}的学生已经删除'.format(stu_id))
                    else:
                        print('未找到学号{}的学生信息'.format(stu_id))
            else:
                print('无学生信息')
                break
            showall()
            answer=input('是否继续删除！')
            if answer=='Y' or answer=='y':
                continue
            else:
                break
def totol():
    if os.path.exists(filename):
        with open(filename,'r',encoding='utf-8') as file:
            stu_list=file.readlines()
            if stu_list:
                print('一共{}学生'.format(len(stu_list)))
            else:
                print('还没有录入学生信息！')
    else:
        print('暂未保存数据信息')
def update():
    pass
def sort():
    showall()
    if os.path.exists(filename):
        with open(filename,'r',encoding='utf-8') as file:
            stu_list1=file.readlines()
            stu_new=[]
            for item in stu_list1:
                d=dict(eval(item))
                stu_new.append(d)

    else:
        print('暂未保存数据信息')
        return
    asc_or_desc=input('请选择(0:升序,1:降序)')
    if asc_or_desc=='0':
        asc_or_desc_bool=False
    elif asc_or_desc=='1':
        asc_or_desc_bool=True
    else:
        print('输入信息有误，请重新输入')
        sort()
    mode=input('请选择排序方式：1.英语2.python3.Java4.总成绩')
    if mode=='1':
        stu_new.sort(key=lambda x:int(stu_new['english']),reverse=asc_or_desc_bool)
    elif mode=='2':
        stu_new.sort(key=lambda  x: int(stu_new['python']), reverse=asc_or_desc_bool)
    elif mode=='3':
        stu_new.sort(key=lambda x:int(stu_new['java']),reverse=asc_or_desc_bool)
    elif mode=='4':
        stu_new.sort(key=lambda x:int(stu_new['english'])+int(stu_new['python'])+int(stu_new['java']),reverse=asc_or_desc_bool)
    else:
        print('您的输入有误，请重新输入')
        sort()
    show_student(stu_new)
def showall():
    stu_list=[]
    if os.path.exists(filename):
        with open(filename,'r',encoding='utf-8') as file:
            stu_list1=file.readlines()
            for item in stu_list1:
                stu_list.append(eval(item))
            if stu_list:
                show_student(stu_list)
    else:
        print('暂未保存数据信息')
if __name__ == '__main__':
    main()