python 3.x - discord.py Music Bot: How to Combine a Play and Queue Command

Question

Hello I'm trying to create a music bot but I want it so I can play music and add additional music to a queue with the same command. I've tried to do this but I can't get it to work. Here's the code with play and queue being two separate commands:

@bot.command(pass_context=True)
async def join(ctx):
    await bot.join_voice_channel(bot.get_channel('487315853482786820'))


@bot.command(pass_context=True)
async def leave(ctx):
    voice_client = bot.voice_client_in(ctx.message.server)
    await voice_client.disconnect()


players = {}
queues = {}


def check_queue(id):
    if queues[id] != []:
        player = queues[id].pop(0)
        players[id] = player
        player.start()


@bot.command(pass_context=True)
async def play(ctx, url):
    server = ctx.message.server
    voice_client = bot.voice_client_in(server)
    player = await voice_client.create_ytdl_player(url, after=lambda: check_queue(server.id))
    players[server.id] = player
    player.start()


@bot.command(pass_context=True)
async def queue(ctx, url):
    server = ctx.message.server
    voice_client = bot.voice_client_in(server)
    player = await voice_client.create_ytdl_player(url, after=lambda: check_queue(server.id))

    if server.id in queues:
        queues[server.id].append(player)
    else:
        queues[server.id] = [player]
    await bot.say('Video queued.')


@bot.command(pass_context=True)
async def pause(ctx):
    id = ctx.message.server.id
    players[id].pause()


@bot.command(pass_context=True)
async def stop(ctx):
    id = ctx.message.server.id
    players[id].stop()


@bot.command(pass_context=True)
async def resume(ctx):
    id = ctx.message.server.id
    players[id].resume()

Answer 1

You need some sort of queue system where song requests are stored in the queue and a loop that checks if any item is in the queue, grabbing the first item in the queue if it's available. If no songs are in the queue, then the loop waits until a song is added. You can use asyncio.Queue() and asyncio.Event() to do this.

import asyncio
from discord.ext import commands

client = commands.Bot(command_prefix='!')
songs = asyncio.Queue()
play_next_song = asyncio.Event()


@client.event
async def on_ready():
    print('client ready')


async def audio_player_task():
    while True:
        play_next_song.clear()
        current = await songs.get()
        current.start()
        await play_next_song.wait()


def toggle_next():
    client.loop.call_soon_threadsafe(play_next_song.set)


@client.command(pass_context=True)
async def play(ctx, url):
    if not client.is_voice_connected(ctx.message.server):
        voice = await client.join_voice_channel(ctx.message.author.voice_channel)
    else:
        voice = client.voice_client_in(ctx.message.server)

    player = await voice.create_ytdl_player(url, after=toggle_next)
    await songs.put(player)

client.loop.create_task(audio_player_task())

client.run('token')