python实现图书管理系统

# 用户注册
def logon():
    print("欢迎来到图书管理系统注册页面~")
    username = input("请输入用户名：")
    if len(username)<6:
        print("用户名不能小于6个字符")
    else:
        email = input("请输入邮箱：")
        password = input("请输入密码：")
        if len(password)<8:
            print("密码不能少于8位")
        else:
            rpassword = input("请确认密码：")
            if password ==rpassword:
                print("注册成功！")
                # 函数调用，每追加一列数据都进行换行 每一个数据之间都有空格
                preserve_data(path,['\n'+ username,'   '+ email,'   '+ password])
                return True
            else:
                print("两次输入的密码不一致，请从新输入！")
                # 递归调用
                logon()


# 保存数据到文件
path = r'D:\Python\python-qf\文件操做\os.path\复制文件夹\案例练习\users\user.txt'
def preserve_data(file_path,data):
    # 将字符串转换为bytes，由于write写入的是字节流，不能是字符串 当为w时须要解码
    # data = data.encode()
    # 打开文件，追加数据到文件
    with open(file_path,'a') as wstream:
        # 判断是否可写
        if wstream.writable():
            wstream.writelines(data)
        else:
            print("没有权限！")


# 用户登陆
def login():
    print("欢迎来到图书管理系统登陆页面~")
    tips = input("是否已经注册？(yes/no)")
    if tips =='yes':
        while True:
            username = input("输入用户名：")
            password = input("输入密码：")
            # 读取文件时可能会出现找不到文件的异常，所以使用try except
            try:
                # 读取文件中的内容
                with open(path, 'rb') as stream:
                    # 读取多行保存到列表中，列表中保存的是二进制，字节
                    result = stream.readlines()
                    # print(result)
                    # 列表推导式，循环遍历列表，将字节解码为字符串放在一个新列表uesr_list
                    uesr_list = [i.decode() for i in result]
                    # print(uesr_list)
                    # 循环遍历列表，检查输入的用户名和密码是否在字符串中
                    for i in uesr_list:
                        # print(i)
                        if username in i and password in i:
                            print("登陆成功")
                            operate(book_path,username)
                            break
                    else:
                        raise Exception("用户名或密码错误，请从新输入！")

            except Exception as err:
                print(err)
            # 没有异常时执行else语句
            else:
                break
    else:
        print("您还未注册，请先注册后再登陆！")
        # 递归
        logon()

# 查询图书
def find_books(path):
    try:
        with open(path, 'r') as rstream:
            # readlines读到的内容是一个列表
            container = rstream.readlines()
            # 经过列表推导式获得新的列表，即每一个元素去掉后面的换行符号
            new_container = [books_name.rstrip('\n') for books_name in container]
            for b_name in new_container:
                # 打印图书+《》
                print("《{}》".format(b_name))

    except Exception as err:
        print("错误缘由：",err)

#添加图书
def add_book(b_path,username):
    # 添加前首先判断是不是管理员
    permission(b_path, username)
    # 追加图书 不能是w ,不然会清空以前的内容
    with open(b_path, 'a') as wstream:
        # 判断是否可写
        if wstream.writable:
            msg = input("请输入书名：")
            try:
                # 添加书籍以前判断某本书是否已经添加
                with open(b_path) as rstream:
                    while True:
                        line = rstream.readline()
                        # 去掉右边的换行
                        line = line.rstrip('\n')
                        # 当找到空行是若是尚未找到与输入的书名一致的时候，就添加输入的书名
                        if not line:
                            book = '\n' + msg
                            wstream.write(book)
                            print("添加成功")
                            break
                        else:
                            # 输入的图书和读到的行有一致的则提示不能重复添加
                            if line == msg:
                                print("{}已添加,请不要重复添加哦~".format(msg))
                                break
            except Exception as err:
                print("错误缘由：", err)
        else:
            print("没有权限")


# 修改图书
def update_book(b_path,username):
    permission(b_path, username)
    try:
        with open(b_path, 'r') as rstream:
            container = rstream.read()
            # 经过'\n'来分割字符串，返回结果是列表
            container = container.split('\n')
            # print(container)
            # 删除前先展现有哪些图书
            find_books(book_path)
            book_name = input("请输入须要修改的图书书名：")
            # 循环遍历修改书名
            for i in range(len(container)):
                if book_name == container[i]:
                    rbook_name = input("请输入修改后的图书书名：")
                    container[i] = rbook_name + '\n'
                else:
                    # 列表中的每一个书名后面加换行符，用于写入文件时换行
                    container[i] = container[i] + '\n'
            # print(container)
            # 将书名更新后的内容以writelines写入文件中  writelines(可迭代)
            with open(b_path, 'w') as wwstream:
                wwstream.writelines(container)
            print("修改为功")
    except Exception as err:
        print("错误缘由：", err)



# 删除图书
def del_book(b_path,username):
    permission(path, username)
    try:
        with open(b_path, 'r') as rstream:
            container = rstream.read()
            # 经过'\n'来分割字符串，返回结果是列表
            container = container.split('\n')
            # print(container)
            # 展现有哪些图书
            find_books(book_path)
            book_name = input("请输入须要删除的图书书名：")
            # 循环遍历修改书名
            for i in range(len(container) - 1):
                if book_name == container[i]:
                    container.remove(container[i])
                else:
                    # 列表中的每一个书名后面加换行符，用于写入文件时换行
                    container[i] = container[i] + '\n'
            # print(container)
            # 将书名删除后的内容以writelines写入文件中  writelines(可迭代)
            with open(b_path, 'w') as wwstream:
                wwstream.writelines(container)
            print("删除成功")
    except Exception as err:
        print("错误缘由：", err)

# 借书
def borrow_book(username):
    while True:
        print("图书列表：")
        find_books(book_path)
        borrow_books = input("请选择图书：")
        try:
            with open('../user_books/user_books.txt') as rstream:
                # 每次读取一行
                lines = rstream.readline()
                lines = lines.rstrip('\n')
                # 将读到的内容经过空格分割保存到列表
                lines = lines.split(' ')
                # 判断输入的书是否已被借走
                if borrow_books not in lines:
                    # print(lines)
                    # 借书以前先判断该用户以前是否借过，若是借过，就在后面累加图书，用，分割图书
                    # for user_book in lines:
                    if username in lines:
                        with open('../user_books/user_books.txt', 'a') as wstream:
                            # 判断以前是否借过某本书
                            if borrow_books not in lines:
                                wstream.write(' {}'.format(borrow_books))
                                print("借书成功")
                                break
                            else:
                                print("您已借过此书，请重新选择！")
                                break
                    else:
                        # 将选择的图书与用户名一块儿保存到文件中
                        with open('../user_books/user_books.txt', 'a') as wstream:
                            wstream.write('\n{} {}\n'.format(username, borrow_books))
                            print("借书成功")
                            break
                else:
                    print("<<{}>>已被用户{}借走，请从新选择~".format(borrow_books,lines[0]))
        except Exception as err:
            print("错误缘由：", err)


# 还书
def return_book(username):
    try:
        with open('../user_books/user_books.txt') as rstream:
            # print("{}您已借阅，未归还图书以下：".format(username))
            # 读到的结果是列表
            lines = rstream.readlines()
            # 遍历列表，将里面的元素再拆分为列表
            for i in range(len(lines)):
                # 去掉换行
                lines[i] = lines[i].rstrip('\n')
                lines[i] = lines[i].rstrip(' ')
                lines[i] = lines[i].split(' ')
                for ii in range(len(lines[i])-1):
                    # 只打印登陆用户借阅的图书
                    if username == lines[i][0]:
                        print("{}您已借阅，未归还图书以下：".format(username))
                        print(lines[i][ii+1])
                        msg = input("请选择你要归还的图书：")
                        with open('../user_books/user_books.txt') as rstream:
                            lines = rstream.readlines()
                            for i in range(len(lines)):
                                if username in lines[i] and msg in lines[i]:
                                    # 用空字符串替换msg,即表示删除归还的图书
                                    lines[i] = lines[i].replace(msg, '')
                                    with open('../user_books/user_books.txt', 'w') as wstream:
                                        # 将变动后的列表再写入文件，只变动当前用户的图书信息
                                        wstream.writelines(lines)
                                        print("归还成功！")
                                        break

                            with open('../user_books/user_books.txt') as rstream:
                                lines = rstream.readlines()
                                for i in range(len(lines)):
                                    lines[i] = lines[i].rstrip('\n')
                                    lines[i] = lines[i].rstrip(' ')
                                    lines[i] = lines[i].split(' ')
                                    # print(type(lines[i]))
                                    for ii in range(len(lines[i])):
                                        # 图书归还成功后判断列表中只有用户名了，若是只有用户名则将用户名用空字符串代替
                                        if username == lines[i][0] and len(lines[i]) == 1:
                                            lines[i][0] = lines[i][0].replace(lines[i][0], '')
                                            lines.append(lines[i][0])
                                # print(lines)
                                str = ''
                                for i in range(len(lines)):
                                    for ii in range(len(lines[i])):
                                        # 将嵌套列表中的元素取出来拼接成字符串
                                        str += lines[i][ii] + ' '
                                    str += '\n'
                                # 遍历完毕删除以前列表里面嵌套的列表，追加字符串str
                                lines.clear()
                                lines.append(str)

                                # print(lines)
                                # 将更新后的列表写入文件
                                with open('../user_books/user_books.txt', 'w') as wstream:
                                    wstream.writelines(lines)
                    else:
                        print("您尚未借阅记录哦~")

    except Exception as err:
        print("错误缘由：", err)

# 查看我的信息
def look_person_info(path,username):
    with open(path) as rstream:
        while True:
            line = rstream.readline()
            if not line:
                break
            else:
                line = line.split('   ')
                # 列表推导式
                line = [info.strip('\n') for info in line]
                if username in line:
                    print("----我的信息----")
                    print("用户名：",line[0])
                    print("邮箱：", line[1])
                    print("密码：", line[2])


# 修改我的信息
def update_password(path,username):
    tips = input("请选择操做：\n 1.修改邮箱\n 2.修改密码\n")

    # 修改邮箱
    if tips =='1':
        new_email = ''
        line = []
        try:
            with open(path) as rstream:
                while True:
                    line = rstream.readline()
                    if not line:
                        break
                    line = line.split('   ')
                    # 去掉密码后面的换行符
                    line[2] = line[2].rstrip('\n')
                    if username == line[0]:
                        new_email = input("请输入新邮箱：")
                        line[1] = new_email
                        break
        except Exception as err:
            print(err)

        else:
            # 将新修改邮箱后的用户的全部信息追加到文件夹
            with open(path, 'a') as wstream:
                for i in range(len(line)):
                    if i == 0:
                        # 遍历列表，第一个列表元素须要前面须要加换行，后面须要加空格与其余元素分割
                        line[i] = '\n' + line[i] + '   '
                    else:
                        line[i] = line[i] + '   '
                wstream.writelines(line)
                print("修改为功")
            # 删除修改邮箱以前用户的信息
            with open(path) as rstream:
                # 读取多行
                lines = rstream.readlines()
                i = 0
                l = len(lines)
                while i < l:
                    # 当 当前用户名在用户信息行且新的邮箱不在时就删除以前的用户信息，不会删除其余用户的信息
                    if username in lines[i] and new_email not in lines[i]:
                        lines.remove(lines[i])
                    i += 1
                    l -= 1
                # 删除旧邮箱对应的当前用户信息后，再将新邮箱对应的用户信息以及其余用户的信息重新写入到文件
                with open(path, 'w') as wstream:
                    wstream.writelines(lines)
    # 修改密码
    elif tips =='2':
        new_password = ''
        line = []
        try:
            with open(path) as rstream:
                while True:
                    line = rstream.readline()
                    if not line:
                        break
                    line = line.split('   ')
                    # 去掉密码后面的换行符
                    line[2] = line[2].rstrip('\n')
                    if username == line[0]:
                        new_password = input("请输入新密码：")
                        # 判断新密码与旧密码是否一致
                        if new_password ==line[2]:
                            # 抛出异常
                            raise Exception("新密码不能与旧密码相同哦~")
                        else:
                            line[2] =new_password
                            break
        # 能够捕获到前面raise抛出的异常
        except Exception as err:
            print(err)

        else:
            # 将新修改密码后的用户的全部信息追加到文件夹
            with open(path,'a') as wstream:
                for i in range(len(line)):
                    if i ==0:
                        # 遍历列表，第一个列表元素须要前面须要加换行，后面须要加空格与其余元素分割
                        line[i] = '\n'+line[i]+'   '
                    else:
                        line[i] = line[i] +'   '
                wstream.writelines(line)
                print("修改为功")
            # 删除修改密码以前用户的信息
            with open(path) as rstream:
                # 读取多行
                lines = rstream.readlines()
                i =0
                l = len(lines)
                while i < l:
                    # 当 当前用户名在用户信息行且新的密码不在时就删除以前的用户信息，不会删除其余用户的信息
                    if username in lines[i] and new_password not in lines[i]:
                        lines.remove(lines[i])
                    i+=1
                    l-=1
                # 删除旧密码对应的当前用户信息后，再将新密码对应的用户信息以及其余用户的信息重新写入到文件
                with open(path,'w') as wstream:
                    wstream.writelines(lines)

# 我的信息
def person_information(path,username):
    tips = input("请选择操做：\n 1.查看我的信息\n 2.修改我的信息\n")
    if tips =='1':
        look_person_info(path,username)
    elif tips =='2':
        update_password(path, username)

# 只有管理员才能够进行图书的增删改操做
def permission(user_path,username):
    try:
        with open(user_path) as rstream:
            while True:
                line = rstream.readline()
                # 读到空行跳出循环
                if not line:
                    break
                # 经过3个空格将字符串line分割为一个列表，存储三个值
                line = line.split('   ')
                # 循环遍历列表，去掉列表中每一个元素后面的换行，若是有就去掉，没有就不取掉
                for i in range(len(line)):
                    line[i] = line[i].rstrip('\n')
                # 判断是否管理员，若是是就能够进行添加操做
                if username == 'admin123':
                    pass
                else:
                    print("只有管理员才能够进行该操做~".format(username))
                    # 不是管理员将回到操做页面
                    operate(path, username)
    except Exception as err:
        print("错误缘由：",err)




# 图书增删改借还操做
book_path = '../books/books.txt'
# book_list = ['水浒传\n','红楼梦\n','廊桥遗梦']
def operate(b_path,username):
    while True:
        msg = input("请选择操做:\n 1.查询图书\n 2.添加图书\n 3.修改图书\n 4.删除图书\n 5.借书\n 6.归还图书\n 7.我的信息\n 8.退出登陆\n")
        # 查询图书
        if msg =='1':
            find_books(book_path)
        # 添加图书
        elif msg =='2':
            add_book(b_path, username)
        # 修改图书
        elif msg =='3':
            update_book(b_path, username)
        # 删除图书
        elif msg =='4':
            del_book(b_path, username)
        # 借书
        elif msg =='5':
            borrow_book(username)
        # 还书
        elif msg =='6':
            return_book(username)
        #查看、修改我的信息
        elif msg =='7':
            person_information(path, username)

        # 退出登陆
        elif msg =='8':
            msg = input("肯定退出登陆吗？(yes/no)")
            if msg == 'yes':
                break



login()