文件user_id.txt包含的是注册的用户名，请编写程序，读取该文件中的用户名，并通过在用户名后添加@airlines123.com来生成该用户的邮箱，将用户名和对应的邮箱保存至新建的user_mailbox.csv文件中，其结果如下图所示，要求文件中带有'user_id'和 'user_mailbox'的表头

可以使用Python语言来实现，代码如下：

import csv# open user_id.txt and user_mailbox.csv
with open('user_id.txt', 'r') as f1, open('user_mailbox.csv', 'w') as f2:
    # create reader and writer
    reader = f1.readlines()
    writer = csv.writer(f2)
    # write table head
    writer.writerow(["user_id", "user_mailbox"])
    # read user_id from file and generate user_mailbox 
    for user_id in reader:
        user_mailbox = user_id.strip() + "@airlines123.com"
        # write user_id and user_mailbox to user_mailbox.csv
        writer.writerow([user_id.strip(), user_mailbox])