discord.py加载扩展报错：'Client'对象无'load_extension'属性

尝试将discord.py的命令拆分到music.py文件中时，运行出现错误：AttributeError: 'Client' object has no attribute 'load_extension'，此前还遇到过'Client' object has no attribute 'add_cog'错误。

以下是原代码：

main.py #

import discord
import music
from discord.ext import commands

client = commands.Bot(command_prefix="!", intents=discord.Intents.all())
token = ""

cogs = [music]

@client.event
async def on_ready():
    await client.load_extension(cogs.commands)
    print(f"Logged in as {client.user})")

client.run(token)

music.py #

import discord
from discord.ext import commands
import youtube_dl

class music(commands.Cog):
    def __init__(self, client):
        self.client = client

    @commands.command()
    async def join(self, ctx):
        if ctx.author.voice is None:
            await ctx.send("First join to voice channel")
            voicechannel = ctx.author.voice.channel
            if ctx.voicechannel is None:
                await voicechannel.join()
            else:
                await voicechannel.move_to(ctx.voicechannel)

    @commands.command()
    async def disconnect(self, ctx):
        await ctx.voice_client.disconnect()

    @commands.command()
    async def play(self,ctx,url):
        ctx.voice_client.stop()
        
        FFMPEG_OPTIONS = {'before options': '-reconnect 1 -reconnect_streamed 1 -reconnect_delay_max 5', 'options': '-vn' }
        YDL_OPTIONS = {'format':"bestaudio"}
        vc = ctx.voice_client 
        
        with youtube_dl.YoutubeDL(YDL_OPTIONS) as ydl:
            info = ydl.extract_info(url, download=False)
            url2 = info['formats'][0]['url']
            source = await discord.FFmpegOpusAudio.from_probe(url2, **FFMPEG_OPTIONS)
            vc.play(source)

    @commands.command()
    async def resume(self, ctx):
        await ctx.voice_client.resume()
        await ctx.send("resumed")
    
    @commands.command()
    async def pause(self, ctx):
        await ctx.voice_client.pause()
        await ctx.send("paused")

async def setup(client):
   await client.add_cog(music(client))  

1. 扩展加载方式错误 #

你创建的是commands.Bot实例（继承自Client），但加载扩展的代码写法错误：

• await client.load_extension(cogs.commands) 是错误用法，load_extension需要传入模块名字符串（比如"music"），而非模块对象的属性
• cogs = [music] 是导入的模块对象列表，正确加载方式是遍历列表，传入模块的名称

2. join命令逻辑错误 #

• 当ctx.author.voice is None时，尝试获取ctx.author.voice.channel会直接报错，因为ctx.author.voice已经是None
• 缩进错误：频道判断和连接代码应放在if块外部，仅当用户在语音频道时执行

3. 额外注意：youtube_dl已停止维护 #

youtube_dl目前不再更新，建议替换为yt-dlp，安装命令：pip install yt-dlp，代码中只需将import youtube_dl改为import yt_dlp as youtube_dl即可。

main.py #

import discord
import music
from discord.ext import commands

client = commands.Bot(command_prefix="!", intents=discord.Intents.all())
token = ""

cogs = [music]

@client.event
async def on_ready():
    # 遍历加载所有cog模块
    for cog in cogs:
        await client.load_extension(cog.__name__)
    print(f"Logged in as {client.user}")  # 修正字符串闭合错误

client.run(token)

music.py #

import discord
from discord.ext import commands
# 推荐替换为yt-dlp
# import yt_dlp as youtube_dl
import youtube_dl

class Music(commands.Cog):  # 类名首字母大写符合PEP8规范
    def __init__(self, client):
        self.client = client

    @commands.command()
    async def join(self, ctx):
        if ctx.author.voice is None:
            return await ctx.send("请先加入一个语音频道！")
        
        voice_channel = ctx.author.voice.channel
        if ctx.voice_client is None:
            await voice_channel.join()
        else:
            await ctx.voice_client.move_to(voice_channel)  # 修正move_to调用对象

    @commands.command()
    async def disconnect(self, ctx):
        if ctx.voice_client:
            await ctx.voice_client.disconnect()
        else:
            await ctx.send("我不在任何语音频道中！")

    @commands.command()
    async def play(self, ctx, url):
        if not ctx.voice_client:
            return await ctx.send("请先让我加入语音频道！")
        
        ctx.voice_client.stop()
        
        FFMPEG_OPTIONS = {
            'before_options': '-reconnect 1 -reconnect_streamed 1 -reconnect_delay_max 5',
            'options': '-vn'
        }
        YDL_OPTIONS = {'format': "bestaudio"}
        
        with youtube_dl.YoutubeDL(YDL_OPTIONS) as ydl:
            info = ydl.extract_info(url, download=False)
            url2 = info['formats'][0]['url']
            source = await discord.FFmpegOpusAudio.from_probe(url2, **FFMPEG_OPTIONS)
            ctx.voice_client.play(source)
            await ctx.send(f"正在播放: {info['title']}")

    @commands.command()
    async def resume(self, ctx):
        if ctx.voice_client and ctx.voice_client.is_paused():
            ctx.voice_client.resume()
            await ctx.send("已恢复播放！")
        else:
            await ctx.send("当前没有暂停的音频！")
    
    @commands.command()
    async def pause(self, ctx):
        if ctx.voice_client and ctx.voice_client.is_playing():
            ctx.voice_client.pause()
            await ctx.send("已暂停播放！")
        else:
            await ctx.send("当前没有正在播放的音频！")

async def setup(client):
    await client.add_cog(Music(client))

内容的提问来源于stack exchange，提问作者Kubzel