Python(学生查询系统)

###模块
import os
import time

# 自定义文件名
filename = 'student.txt'


#####菜单操作*
def main():  ###
    while True:
        menu()
        choice = int(input('请选择:'))
        if choice in [0, 1, 2, 3, 4, 5, 6, 7]:
            if choice == 0:
                answer = input('你确定要退出系统?y/n')
                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:
                modify()
            elif choice == 6:
                total()
            elif choice== 7:
                show()
            elif choice== 5:
                sort()



########显示菜单*
def menu():  ####显示菜单
    print('============学生管理==============')
    print('--------------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\t0.退出系统')
    print('---------------------------')  ################显示菜单


###录入学生信息*
def insert():
    student_list = []
    while True:
        id = input('请输入ID(如1001):')
        if not id:
            break
        name = input('请输入姓名')
        if not name:
            break
        try:
            englist = 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,不是证书类型,请重新输入')
            continue
        ####将录入的学生信息保存到字典
        student = {'id': id, 'name': name, 'english': englist, 'python': python, 'java': java}
        # 添加到列表中
        student_list.append(student)
        answer = input('是否继续添加?y/n \n')
        if answer == 'y':
            continue
        else:
            break

        ##调用save()函数

    ##调用save()函数
    save(student_list)
    print('学生信息录入完毕!')


#####1录入保存操作*
def save(lst):
    try:
        stu_txt = open(filename, 'a', encoding='utf-8')
    except:
        stu_txt = open(filename, 'a+', encoding='utf-8')
    for item in lst:
        stu_txt.write(str(item) + '\n')
    stu_txt.close()


####2查询学生信息 *
def search():
    student_quert = []
    while True:
        id = ''
        name = ''
        if os.path.exists(filename):
            mode = input('按IP查询输入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('您输入有误,请重新输入')
                search()  ####重新调用自己函数
            with open(filename, 'r', encoding='utf-8') as rfile:
                student = rfile.readlines()
                for item in student:
                    d = dict(eval(item))
                    if id != '':
                        if d['id'] == id:
                            student_quert.append(d)
                    elif name != '':
                        if d['name'] == name:
                            student_quert.append(d)
            ###显示查询结果
            show_student(student_quert)
            # 清空列表
            student_quert.clear()
            anser = input('是否继续查询?y/n \n')
            if anser == 'y':
                continue  #####跳出本次循环,执行下一次
            if anser == 'n':
                break
        else:
            print('暂未保存学生信息')
            return


####输出2 查询学生结果*
def show_student(lst):
    if len(lst) == 0:
        print('没有查询到学生信息,无数据')
        return
    #####定义标题显示格式
    format_title = '{:^16}{:^12}{:^18}{:^10}{:^18}{:^18}'
    print(format_title.format('ID', '姓名', '英语成绩', 'Python成绩', 'java成绩', '总成绩'))
    ####定义内容的显示格式
    format_data = '{:^6}\t{:^12}\t{:^8}\t{:^10}\t{:^8}\t{:^18}'
    for item in lst:
        print(format_data.format(item.get('id'),
                                 item.get('name'),
                                 item.get('english'),
                                 item.get('python'),
                                 item.get('java'),
                                 int(item.get('english')) + int(item.get('python')) + int(item.get('java')),

                                 ))


###3删除学生信息*
def delete():
    while True:
        student_id = input('请输入要删除的学生ID:')
        if student_id != '':
            if os.path.exists(filename):
                with open(filename, 'r', encoding='utf-8') as file:
                    student_old = file.readlines()
            else:
                student_old = []
            flag = False  ######标记是否删除
            if student_old:
                with open(filename, 'w', encoding='utf-8') as wfile:
                    d = {}
                    for item in student_old:
                        d = dict(eval(item))  ###将字符串转成字典
                        if d['id'] != student_id:  # d['id'] 为d 列表中id为XX
                            wfile.write(str(d) + '\n')
                        else:
                            flag = True
                    if flag:
                        print(f'id为{student_id}的学生已删除')
                    else:
                        print(f'没有找到ID为{student_id}的学生')
            else:
                print('无学生信息,将在两秒钟后返回主菜单')
                time.sleep(2)
                break
            show()  ####删除后重新显示所有学生信息
            answer = input('是否继续删除?/n\n')
            if answer == 'y':
                continue
            else:
                break


###4修改学生信息*
def modify():
    show()
    if os.path.exists(filename):
        with open(filename, 'r', encoding='utf-8') as rfile:
            student_old = rfile.readlines()
    else:
        return
    student_id = input('请输入要修改的学生ID:')
    # if student_id != '':   ####如果无学生信息
    with open(filename, 'w', encoding='utf-8') as wfile:
        for item in student_old:
            d = dict(eval(item))
            if d['id'] == student_id:
                print(f'找到学生{student_id}信息可以修改)')
                while True:
                    try:
                        d['name'] = input('请输入姓名')
                        d['english'] = input('enlish')
                        d['python'] = input('python')
                        d['java'] = input('java')
                    except:
                        print('输入有误,请重新输入')
                    else:
                        break
                wfile.write(str(d) + '\n')
                print('修改成功!!!')
            else:
                wfile.write(str(d) + '\n')
        answer = input('是否继续秀嘎其他学生信息? y/n \n')
        if answer == 'y':
            modify()
    # else:
    #     print('无学生信息,将在两秒钟后返回主菜单')
    #     time.sleep(2)


####5排序
def sort():
    show()
    if os.path.exists(filename):
        with open(filename,'r',encoding='utf-8')as rfile:
            student_list=rfile.readlines()
        student_new=[]
        for item in student_list:
            d=dict(eval(item))
            student_new.append(d)
    else:
        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('你的输入有误')
        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java成绩排序 0.按总成绩)')
    if mode=='1':
        student_new.sort(key=lambda x:int(x['english']),reverse=asc_or_desc_bool)
    elif mode=='2':
        student_new.sort(key=lambda x:int(x['python']),reverse=asc_or_desc_bool)
    elif mode=='3':
        student_new.sort(key=lambda x:int(x['java']),reverse=asc_or_desc_bool)
    elif mode=='0':
        student_new.sort(key=lambda x:int(x['english'])+int(x['python'])+int(x['java']),reverse=asc_or_desc_bool)
    else:
        print('输入有无,重新输入')
        sort()
    show_student(student_new)


###6查询学生总人数
def total():
    if os.path.exists(filename):
        with open(filename, 'r', encoding='utf-8') as rfile:
            students = rfile.readlines()
            if students:
                print(f'一共{len(students)}名学生,2s后返回主菜单')  ###判断列表总长度
                time.sleep(2)
            else:
                print('还没有录入学生')
    else:
        print('无保存数据')


####7输出学生列表
def show():
    student_lst=[]
    if os.path.exists(filename):
        with open(filename,'r',encoding='utf-8') as rfile:
            students=rfile.readlines()
            for item in students:
                student_lst.append(eval(item))
            if student_lst:
                show_student(student_lst)   #####show_student是输出函数
                time.sleep(5)
    else:
        print('未保存学生信息')



#######
if __name__ == '__main__':
    main()