@bot.event in a cog discord.py

Question

I was wondering if it is possible to use @bot.event in a cog for discord.py. I have tried doing

@self.bot.event
async def on_member_join(self, ctx, member):
    channel = discord.utils.get(member.guild.channels, name='general')
    await channel.send("hello")

in my cog class, but I get the error

NameError: name 'self' is not defined

even though I define self.bot in my __init __.

Is there a different way of doing bot.event in cogs, or is it just not possible?

Answer 1

To register an event from a new-style cog, you must use the commands.Cog.listener decorator. Below is mental's example converted to the new style:

from discord.ext import commands

class Events(commands.Cog):
    def __init__(self, bot):
        self.bot = bot

    @commands.Cog.listener()
    async def on_ready(self):
        print('Ready!')
        print('Logged in as ---->', self.bot.user)
        print('ID:', self.bot.user.id)

    @commands.Cog.listener()
    async def on_message(self, message):
        print(message)

def setup(bot):
    bot.add_cog(Events(bot))

Answer 2

I do not reccomend qspitzers answer since this is not a sensible way of moving your events to a cog and the answer may throw some unknown/unexpected exceptions.

Instead do something like this.

from discord.ext import commands

class Events:
    def __init__(self, bot):
        self.bot = bot

    async def on_ready(self):
        print('Ready!')
        print('Logged in as ---->', self.bot.user)
        print('ID:', self.bot.user.id)

    async def on_message(self, message):
        print(message)

def setup(bot):
    bot.add_cog(Events(bot))

Keep in mind that to place an event inside a cog you do not need a decorator for it. Also the events inside the cog do not overide the default events and these events will be stored in bot.extra_events.