Discord Bot的!roblox命令中username变量无值问题求助

我开发了一个Discord Bot，该Bot通过!roblox <username>命令触发，计划调用Roblox API查询目标用户的群组等级、好友数量、账号年龄。但目前username变量始终没有存储值，我添加了print语句排查也没有输出。以下是我的代码：

import discord
import requests

intents = discord.Intents.default()
intents.members = True

client = discord.Client(intents=intents)

@client.event
async def on_ready():
    print('Logged in as {0.user}'.format(client))

@client.event
async def on_message(message):
    if message.author == client.user:
        return

    if message.content.startswith('!roblox'):
        # Get the username from the user input
        username = message.content.split('!roblox ')[1]
        print(username) 
        # Make a request to the Roblox API to get the user's data
        url = f"https://users.roblox.com/v1/users/search?keyword={username}&limit=10"
        response = requests.get(url)
        data = response.json()

        # Check if the user exists
        if "data" in data and data["data"]:
            user_id = data["data"][0]["id"]

            # Get the user's account age
            url = f"https://users.roblox.com/v1/users/{user_id}"
            response = requests.get(url)
            data = response.json()
            created_at = data["created"]

             # Get the user's friend count
             url = f"https://friends.roblox.com/v1/users/{user_id}/friends/count"
             response = requests.get(url)
             data = response.json()
             friend_count = data["count"]

             # Get the user's role name in the group "United States Army"
             url = f"https://groups.roblox.com/v2/users/{user_id}/groups/roles"
             response = requests.get(url)
             data = response.json()

             role_name = None
             for group in data["data"]:
                 if group["group"]["id"] == 3108077:
                     role_name = group["role"]["name"]
                    break

             # Build the response message
            message = f"**Username:** {username}\n"
            message += f"**Account Age:** {created_at}\n"
            message += f"**Friend Count:** {friend_count}\n"
            message += f"**Role in United States Army:** {role_name}" if role_name else ""

        else:
            message = f"Could not find user {username}."

        # Send the response message
        await message.channel.send(message)

client.run('TOKEN')

请问为何username变量没有值，请求帮助！

核心问题 #

你提取用户名的方式存在两个关键问题，导致username无法正常赋值甚至代码直接终止：

1. 索引越界异常：用message.content.split('!roblox ')[1]时，如果用户输入的命令格式错误（比如只打了!roblox没加用户名，或者空格位置不对），split后的列表长度会小于2，直接取索引1会触发IndexError，代码会中断，print(username)根本没机会执行。
2. 命令匹配不严谨：startswith('!roblox')会匹配所有以!roblox开头的消息，比如!robloxian这种错误指令，此时split('!roblox ')只能得到一个元素，同样会触发索引错误。

另外代码还有隐藏问题：你用字符串覆盖了原有的message对象，后续执行await message.channel.send(message)会报错，因为此时message已经不是Discord的Message实例了。

修复步骤 #

1. 安全提取用户名：改用按空格拆分的方式，先判断参数数量：

parts = message.content.split()
# 确保命令格式正确
if len(parts) < 2:
    await message.channel.send("请输入正确格式：!roblox <用户名>")
    return
username = parts[1]
print(username)

2. 严谨匹配命令：直接判断拆分后的第一个元素是否为!roblox，避免误匹配：

if parts[0] == '!roblox':
    # 后续逻辑

3. 避免覆盖Message对象：把回复消息的变量名改成response_msg：

# 构建回复消息
response_msg = f"**Username:** {username}\n"
response_msg += f"**Account Age:** {created_at}\n"
response_msg += f"**Friend Count:** {friend_count}\n"
if role_name:
    response_msg += f"**Role in United States Army:** {role_name}"

# 发送回复
await message.channel.send(response_msg)

4. 添加异常防护：对API请求步骤添加异常捕获，避免Bot崩溃：

try:
    response = requests.get(url)
    response.raise_for_status()  # 捕获HTTP错误
    data = response.json()
except requests.exceptions.RequestException as e:
    await message.channel.send(f"API请求失败：{str(e)}")
    return

内容的提问来源于stack exchange，提问作者FrostZer0