大家好。我一直在为我的 discord 服务器开发一些机器人，在其中一个机器人中我遇到了一个问题，我似乎无法解决。我有一个名为“info”的命令，本质上，这个命令会显示所需用户的一些信息。当我调用命令 ?info [user] 时，它工作正常，直到我故意请求不存在的用户的信息来测试我设置的例外情况。这里'

@laugh.command(pass_context=True)
async def info(ctx, user: discord.Member = None):
    if ctx.message.channel.name != "admin":
        await laugh.send_message(ctx.message.author, "Sorry, you need to be in a text channel called 'admin' for that.")
        return
    if not ctx.message.author.server_permissions.administrator:
        return
    if not user:
        user = ctx.message.author
    try:
        minfo = ("""
{0}'s ID is: {1}
{0}'s status is: {2}
{0}'s highest role is: {3}
{0} joined at: {4}""".format(user.name, user.id, user.status, user.top_role, user.joined_at))
        embed = discord.Embed(title = user.name, description = minfo, color = 0x00D2FF)
        await laugh.say(embed = embed)
    except discord.NotFound:
        await laugh.say("User not found.")

当我运行此代码并将不存在的用户作为参数时，我的异常不起作用，相反，我会将此输出发送到我的控制台：

Ignoring exception in command info
Traceback (most recent call last):
  File "C:\Users\Matthew\AppData\Local\Programs\Python\Python36-32\lib\site-packages\discord\ext\commands\bot.py", line 846, in process_commands
    yield from command.invoke(ctx)
  File "C:\Users\Matthew\AppData\Local\Programs\Python\Python36-32\lib\site-packages\discord\ext\commands\core.py", line 367, in invoke
    yield from self.prepare(ctx)
  File "C:\Users\Matthew\AppData\Local\Programs\Python\Python36-32\lib\site-packages\discord\ext\commands\core.py", line 345, in prepare
    yield from self._parse_arguments(ctx)
  File "C:\Users\Matthew\AppData\Local\Programs\Python\Python36-32\lib\site-packages\discord\ext\commands\core.py", line 304, in _parse_arguments
    transformed = yield from self.transform(ctx, param)
  File "C:\Users\Matthew\AppData\Local\Programs\Python\Python36-32\lib\site-packages\discord\ext\commands\core.py", line 223, in transform
    raise e
  File "C:\Users\Matthew\AppData\Local\Programs\Python\Python36-32\lib\site-packages\discord\ext\commands\core.py", line 221, in transform
    return (yield from self.do_conversion(ctx, converter, argument))
  File "C:\Users\Matthew\AppData\Local\Programs\Python\Python36-32\lib\site-packages\discord\ext\commands\core.py", line 184, in do_conversion
    return instance.convert()
  File "C:\Users\Matthew\AppData\Local\Programs\Python\Python36-32\lib\site-packages\discord\ext\commands\converter.py", line 100, in convert
    raise BadArgument('Member "{}" not found'.format(self.argument))
discord.ext.commands.errors.BadArgument: Member "test" not found

我看过无数的例子和论坛帖子，我唯一获得的知识是错误的根源在于 async def info(ctx, user: discord.Member = None): ，有什么想法我可以做什么吗？