机器人响应频道提及

Question

I've been trying to develop a discord bot in python recently. I made it so that if a message contains a certain number, it will react and send a message. Here is the code in the cog file:

import discord

from discord.ext import commands
    
nice_numbers = ['69', '420']
    
class Auto(commands.Cog):
    def __init__(self, client):
        self.client = client
      
    @commands.Cog.listener()
    async def on_message(self, message):
        
        msg = message.content
    
        if message.author == self.client.user:
             return
    
        if any (word in msg for word in nice_numbers):
             await message.add_reaction('👌')
             await message.channel.send(f'lmao nice')
        
    
def setup(client):
    client.add_cog(Auto(client))

The problem is, the bot also responds with the same message and reaction when a user mentions a certain channel (in this case #general, #super-private-testing, and #resources). I can't seem to fix it or figure out why it's happening. I'm still pretty new to python so can someone please tell me what I'm doing wrong?

Answer 1

Basically what is happening is that mentions have a special syntax within the Discord API where they are basically a bunch of numbers put together.

For example when you are mentioning another user like the following:

Hello @User1234!

The real syntax within the discord message is the following:

Hello <@125342019199458000>!

And in the case of mentioning channels, it works similar, as a channel mentioned like:

#general

Internally would be written as:

<#550012071928922144>

Of course, the problem is that within this big number there could be false positive of finding your nice_numbers . There could be different ways to avoid this, for example you could check if a channel or a user is being mentioned in the message and return in that case.

if message.channel_mentions or message.mentions:
    return

I think a better solution would be to changing the way you are checking if the nice_numbers are within message.content .

Using if word in msg would return true if message.content also includes something like 'My favourite number is 456 69 ' . To overcome this issue it is better to make use of regular expressions .

You can declare a new function like this answers explains, which would return a <match object> if what you pass as parameter is found.

It would be something like this:

import re

def findCoincidences(w):
    return re.compile(r'\b({0})\b'.format(w)).search

findCoincidences('69')('I like 69')    # -> return <match object>
findCoincidences('69')('My favourite number is 45669')                   # -> return None

Answer 2

Expanding on Shunya's answer , you can use message.clean_content instead of message.content :

A property that returns the content in a “cleaned up” manner. This basically means that mentions are transformed into the way the client shows it. eg <#id> will transform into #name.

This will also transform @everyone and @here mentions into non-mentions.

This will prevent you from inadvertently matching against the IDs of channels, users, roles, etc. Of course, if the actual name contains a nice_number , it'll still match.