Creating New Cogs

What is a Cog?

In the words of the Discord API docs, a cog is “a collection of commands, listeners, and optional state to help group commands together”. A more intuitive way to think of what a cog is to recall what a cog is in a machine: an individual component that serves some purpose within the machine. Cogs are a nice way to think of grouping toghether functionalities that the bot should have.

How Can I Set Up a Cog?

1. Create a new python module in the src/cogs/ cogs directory.

2. Open the aforementioned file in your editor of choice and do the following

   1. Copy and paste this expression to initialize logging for the module: logger = getLogger(f"main.{__name__}")

   2. Define a class that inherits from commands.Cog and defines its constructor as the following:

   def __init__(self, client):
       self.client = client
   

   1. To define a new command, create an asynchronous method and decorate it with the @commands.command decorator

That’s it. To pull it all toghether by definining a cog that replys “hello” when the user types the command “/hi” and logs the user that entered the command

from logging import getLogger

from discord.ext import commands
from discord.ext.commands import Bot
from discord.ext.commands.context import Context

class Hello(commands.Cog):

    def __init__(self, client: Bot):
        self.client = client

    @commands.command(alias=['hi'])
    async def say_hello(self, ctx: Context):
        sender = ctx.author
        await sender.send("hello")
        logger.debug(f"{sender} said hi")