Discord.py斜杠命令踢人报错：如何将通知发送到指定频道

我在用Discord.py开发Discord机器人，需要实现通过斜杠命令踢出成员，并将User {member.mention} was kicked because {reason}的通知发送到指定频道，而非命令执行的频道。当前使用的代码如下：

@bot.slash_command(description = "Kick someone", guild_ids=[1041057700823449682])
@commands.has_permissions(kick_members=True)
@option("member",description = "Select member")
@option("reason",description = "Reason for kick (you can leave this empty)")
async def kick(
    ctx, 
    member: discord.Member,
    channel: bot.get_channel(1042042492020863037),
    *, 
    reason=None):
    if reason==None:
      reason="(no reason)"
    await ctx.guild.kick(member)
    await ctx.respond("Done :)")
    await ctx.channel.send(f'User {member.mention} was kicked because {reason}')

运行代码时出现如下报错：

Traceback (most recent call last):
  File "c:\Users\fonti\Documents\Projetos Python\Bot do Discord\Iniciar Bot.py", line 152, in <module>
    async def kick(
  File "C:\Users\fonti\AppData\Local\Programs\Python\Python310\lib\site-packages\discord\bot.py", line 905, in decorator
    self.add_application_command(result)
  File "C:\Users\fonti\AppData\Local\Programs\Python\Python310\lib\site-packages\discord\bot.py", line 127, in add_application_command
    command._set_cog(None)
  File "C:\Users\fonti\AppData\Local\Programs\Python\Python310\lib\site-packages\discord\commands\core.py", line 603, in _set_cog
    self.cog = cog
  File "C:\Users\fonti\AppData\Local\Programs\Python\Python310\lib\site-packages\discord\commands\core.py", line 827, in cog
    self._validate_parameters()
  File "C:\Users\fonti\AppData\Local\Programs\Python\Python310\lib\site-packages\discord\commands\core.py", line 705, in _validate_parameters
    self.options: list[Option] = self._parse_options(params)
  File "C:\Users\fonti\AppData\Local\Programs\Python\Python310\lib\site-packages\discord\commands\core.py", line 745, in _parse_options
    option = Option(option)
  File "C:\Users\fonti\AppData\Local\Programs\Python\Python310\lib\site-packages\discord\commands\options.py", line 210, in __init__
    self.input_type = SlashCommandOptionType.from_datatype(input_type)
  File "C:\Users\fonti\AppData\Local\Programs\Python\Python310\lib\site-packages\discord\enums.py", line 707, in from_datatype
    if datatype.__name__ in ["Member", "User"]:
AttributeError: 'NoneType' object has no attribute '__name__'. Did you mean: '__ne__'?

移除channel参数后机器人可正常运行，但通知会发送到命令执行的频道，而非目标指定频道。

错误原因 #

1. 机器人启动阶段尚未完成与Discord服务器的连接，此时调用bot.get_channel()会返回None，Discord.py在解析命令参数类型时无法识别None，因此抛出AttributeError。
2. 将channel定义为函数参数会被Discord.py当作斜杠命令的可选参数，但你实际需要的是固定发送到指定频道，不需要用户输入。

修正后的代码 #

@bot.slash_command(description = "Kick someone", guild_ids=[1041057700823449682])
@commands.has_permissions(kick_members=True)
@option("member",description = "Select member")
@option("reason",description = "Reason for kick (you can leave this empty)")
async def kick(
    ctx, 
    member: discord.Member,
    *, 
    reason=None):
    if reason is None:
        reason = "(no reason)"
    
    # 执行踢人操作
    await ctx.guild.kick(member)
    # 仅向命令执行者发送操作完成提示
    await ctx.respond("Done :)", ephemeral=True)
    
    # 获取指定通知频道
    target_channel = bot.get_channel(1042042492020863037)
    if target_channel:
        # 发送通知到指定频道
        await target_channel.send(f'User {member.mention} was kicked because {reason}')
    else:
        # 频道不存在时向执行者提示
        await ctx.followup.send("无法找到指定的通知频道，请检查频道ID是否正确", ephemeral=True)

关键说明 #

• 将获取指定频道的逻辑移到函数内部执行，此时机器人已完成连接，能正确获取频道对象。
• 移除函数参数中的channel定义，避免被Discord.py当作命令选项解析。
• 使用ephemeral=True让操作提示仅对命令执行者可见，避免频道刷屏。
• 增加频道不存在的容错处理，防止因频道ID错误导致的异常。

内容的提问来源于stack exchange，提问作者Jack142