AttributeError: __aenter__

I’ve got a following error when running my code:

  File "C:\discord bot\main.py", line 19, in <module>
    asyncio.run(main())
  File "C:\Users\punk102rus\AppData\Local\Programs\Python\Python310\lib\asyncio\runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "C:\Users\punk102rus\AppData\Local\Programs\Python\Python310\lib\asyncio\base_events.py", line 641, in run_until_complete
    return future.result()
  File "C:\discord bot\main.py", line 14, in main
    async with bot:
AttributeError: __aenter__

How can I fix it? Here is the code that I’ve used:

import discord
from discord.ext import commands
from youtubesearchpython import VideosSearch
from yt_dlp import YoutubeDL
import asyncio

class music_cog(commands.Cog):
    def __init__(self, bot):
        self.bot = bot
    
        #all the music related stuff
        self.is_playing = False
        self.is_paused = False

        # 2d array containing [song, channel]
        self.music_queue = []
        self.YDL_OPTIONS = {'format': 'bestaudio/best'}
        self.FFMPEG_OPTIONS = {'options': '-vn'}

        self.vc = None
        self.ytdl = YoutubeDL(self.YDL_OPTIONS)

     #searching the item on youtube
    async def __aenter__(self):
        return self

    async def __aexit__(self, exc_type, exc, tb):

        pass
    def search_yt(self, item):
        if item.startswith("https://"):
            title = self.ytdl.extract_info(item, download=False)["title"]
            return{'source':item, 'title':title}
        search = VideosSearch(item, limit=1)
        return{'source':search.result()["result"][0]["link"], 'title':search.result()["result"][0]["title"]}

    async def play_next(self):
        if len(self.music_queue) > 0:
            self.is_playing = True

            #get the first url
            m_url = self.music_queue[0][0]['source']

            #remove the first element as you are currently playing it
            self.music_queue.pop(0)
            loop = asyncio.get_event_loop()
            data = await loop.run_in_executor(None, lambda: self.ytdl.extract_info(m_url, download=False))
            song = data['url']
            self.vc.play(discord.FFmpegPCMAudio(song, executable= "ffmpeg.exe", **self.FFMPEG_OPTIONS), after=lambda e: asyncio.run_coroutine_threadsafe(self.play_next(), self.bot.loop))
        else:
            self.is_playing = False

    # infinite loop checking 
    async def play_music(self, ctx):
        if len(self.music_queue) > 0:
            self.is_playing = True

            m_url = self.music_queue[0][0]['source']
            #try to connect to voice channel if you are not already connected
            if self.vc == None or not self.vc.is_connected():
                self.vc = await self.music_queue[0][1].connect()

                #in case we fail to connect
                if self.vc == None:
                    await ctx.send("```Could not connect to the voice channel```")
                    return
            else:
                await self.vc.move_to(self.music_queue[0][1])
            #remove the first element as you are currently playing it
            self.music_queue.pop(0)
            loop = asyncio.get_event_loop()
            data = await loop.run_in_executor(None, lambda: self.ytdl.extract_info(m_url, download=False))
            song = data['url']
            self.vc.play(discord.FFmpegPCMAudio(song, executable= "ffmpeg.exe", **self.FFMPEG_OPTIONS), after=lambda e: asyncio.run_coroutine_threadsafe(self.play_next(), self.bot.loop))

        else:
            self.is_playing = False

    @commands.command(name="play", aliases=["p","playing"], help="Plays a selected song from youtube")
    async def play(self, ctx, *args):
        query = " ".join(args)
        try:
            voice_channel = ctx.author.voice.channel
        except:
            await ctx.send("```You need to connect to a voice channel first!```")
            return
        if self.is_paused:
            self.vc.resume()
        else:
            song = self.search_yt(query)
            if type(song) == type(True):
                await ctx.send("```Could not download the song. Incorrect format try another keyword. This could be due to playlist or a livestream format.```")
            else:
                if self.is_playing:
                    await ctx.send(f"**#{len(self.music_queue)+2} -'{song['title']}'** added to the queue")  
                else:
                    await ctx.send(f"**'{song['title']}'** added to the queue")  
                self.music_queue.append([song, voice_channel])
                if self.is_playing == False:
                    await self.play_music(ctx)

    @commands.command(name="pause", help="Pauses the current song being played")
    async def pause(self, ctx, *args):
        if self.is_playing:
            self.is_playing = False
            self.is_paused = True
            self.vc.pause()
        elif self.is_paused:
            self.is_paused = False
            self.is_playing = True
            self.vc.resume()

    @commands.command(name = "resume", aliases=["r"], help="Resumes playing with the discord bot")
    async def resume(self, ctx, *args):
        if self.is_paused:
            self.is_paused = False
            self.is_playing = True
            self.vc.resume()

    @commands.command(name="skip", aliases=["s"], help="Skips the current song being played")
    async def skip(self, ctx):
        if self.vc != None and self.vc:
            self.vc.stop()
            #try to play next in the queue if it exists
            await self.play_music(ctx)


    @commands.command(name="queue", aliases=["q"], help="Displays the current songs in queue")
    async def queue(self, ctx):
        retval = ""
        for i in range(0, len(self.music_queue)):
            retval += f"#{i+1} -" + self.music_queue[i][0]['title'] + "\n"

        if retval != "":
            await ctx.send(f"```queue:\n{retval}```")
        else:
            await ctx.send("```No music in queue```")

    @commands.command(name="clear", aliases=["c", "bin"], help="Stops the music and clears the queue")
    async def clear(self, ctx):
        if self.vc != None and self.is_playing:
            self.vc.stop()
        self.music_queue = []
        await ctx.send("```Music queue cleared```")

    @commands.command(name="stop", aliases=["disconnect", "l", "d"], help="Kick the bot from VC")
    async def dc(self, ctx):
        self.is_playing = False
        self.is_paused = False
        await self.vc.disconnect()
    
    @commands.command(name="remove", help="Removes last song added to queue")
    async def re(self, ctx):
        self.music_queue.pop()
        await ctx.send("```last song removed```")

My guess is that bot does not support async with.
What do the docs for what ever bot is say?

The error traceback that you show here, refers to your main.py file - specifically starting with code that says asyncio.run(main()) in that file. But what you have shown us doesn’t include that code; it’s clearly a different file - so we can only speculate about what is actually happening in the main.py file.

It seems like you mean to use bot as an asynchronous context manager, and I guess that this bot is an instance of the Bot class from the Discord API. (Please don’t make people guess when you want a clear answer!) It also looks like you wrote your own commands.Cog that the bot should use, and tried to write code that will explain how to use that Cog as a context manager. I again guess you are expecting that, when the bot is used as an asynchronous context manager (async with bot:), that it will in turn use its Cogs in the same way (i.e., __aenter__ the Cogs when the bot’s __aenter__ is called, to set everything up, and similarly with __aexit__.)

However, based on the error message, it looks like the Bot class does not actually work this way. To check this, and understand what should be done instead, start by reading the documentation for the Bot class. Or, if you thought it should work because of some documentation or guide that you already read, maybe you need a different (probably newer) version of the Discord.py library to make it work.

By putting the relevant terms in a search engine, I was able to find this Stack Overflow Q&A. It looks to be about the same problem, although the error was reported differently. Does it help?

(It looks like the different error reporting is because of the Python version. For example, if I try an obviously non-working “asynchronous context manager” in Python 3.8, it looks like this:

>>> import asyncio
>>> async def x():
...     async with 1: pass
... 
>>> asyncio.run(x())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.8/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/usr/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete
    return future.result()
  File "<stdin>", line 2, in x
AttributeError: __aexit__

But in Python 3.11, I see a more helpful error:

>>> import asyncio
>>> async def x():
...     async with 1: pass
... 
>>> asyncio.run(x())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.11/asyncio/runners.py", line 190, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/asyncio/base_events.py", line 653, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "<stdin>", line 2, in x
TypeError: 'int' object does not support the asynchronous context manager protocol

If you feel lost reading the above explanation, it is probably because you are biting off more than you can chew. In particular, if you got all (or most) of this code from a tutorial and just want to “fix it”, then it isn’t really possible to help you like this. (I’m worried about this possibility because of how you presented the code.) It’s important to understand fundamental concepts - like what __aenter__ and __aexit__ are for; what a “context manager” is; what async means in Python and how asynchronous programming using it works; etc. - before trying to use third-party libraries, or solve problems, that depend on those concepts.

The Discord API expects you to understand Python’s built-in async API (the async keyword and the asyncio library) first, because writing a Discord bot requires asynchronous programming, and it’s designed build upon asyncio etc. (Since you don’t know when the command will be entered or who will enter it, but the bot needs to be able to keep listening for commands; and if responding to a command involves a lot of work - or waiting for something else, like a Youtube download - then the bot still needs to keep listening while doing that work). Similarly, cleanup with context managers is a fundamental task (you should be familiar with using it in simple command-line programs, for example, to make sure files get cleaned up after using them, even if an error occurs in the code that tries to read or write them). Those two ideas get combined when we use async with, __aenter__ and __aexit__, which brings its own special considerations.