How to delete words that do not match exactly the black list due to additional characters in the word?

Question

I am making a Discord bot that blocks swear words. It can be bypassed by using underscores and/or other symbols attached to the swear word.

How do I get the script to still block these words but not delete characters in general?

Here is my code:

import discord
import random
import string
from discord.ext import commands

client = commands.Bot(command_prefix = 'as-')

with open("badwords2.txt") as file:
    bad_words = file.read().splitlines()

def check_if_allowed(text):

    allowed_characters = string.ascii_uppercase + string.ascii_lowercase 
    
    if character not in allowed_characters: 
        return False

    return True
    
@client.event
async def on_message(message):    
    for bad_word in bad_words:
        if bad_word in message.content.lower().split(" "):
            t = discord.Embed(color=0x039e00, title="Message Removed", description=":x:   Please do not swear. Swearing can result in a mute or ban.")
            t.set_footer(text="DM TheSuperRobert2498#2498 for bot suggestions.")
            await message.channel.send(embed=t)
            await message.delete()
            return

    if not check_if_allowed(message.content):
        t = discord.Embed(color=0x039e00, title="Message Removed", description=":x:  Please do not swear. Swearing can result in a mute or ban.")
        t.set_footer(text="DM TheSuperRobert2498#2498 for bot suggestions.")
        await message.channel.send(embed=t)
        await message.delete()
        return


client.run('TOKEN')

score 0 · Answer 1 · answered Jan 16 '21 at 18:59

If my message is "hey guys @#@@_badWord@@ what's up?" then, message.content.lower().split(" ") is ["hey", "guys", "@#@@_badWord@@", "what's", "up?"]

So you can be creative with this list that you are checking.

Maybe do

[re.sub(r'\W+', ' ', word) for word in content.message.content.lower().split(" ")]

which will create a new list (using list comprehension) that has each word with the special characters removed (using RegEx substitution)

See: How to remove special characters except space from a file in python?

I also recommend making this into a function so you don't have to write the code twice:

t = discord.Embed(color=0x039e00, title="Message Removed", description=":x:   Please do not swear. Swearing can result in a mute or ban.")
t.set_footer(text="DM TheSuperRobert2498#2498 for bot suggestions.")

score 0 · Answer 2 · answered Jan 16 '21 at 19:10

You can try and remove all special character from the words with the re.sub() function from the re module:

    clearMessage = re.sub('[^A-Za-z0-9]+', '', message.content))

And remove the spaces:

    clearMessage = clearMessage.replace(" ","")

If you put it in your code it would look something like this:

import random
import string
import re
from discord.ext import commands

client = commands.Bot(command_prefix = 'as-')

with open("badwords2.txt") as file:
    bad_words = file.read().splitlines()

def check_if_allowed(text):

    allowed_characters = string.ascii_uppercase + string.ascii_lowercase #creates a string containing all upper- and lower- case letters.

    if character not in allowed_characters: #checks if the character is in the set of allowed characters, and returns false if not
        return False

    return True #returns true if every character in the input is allowed
    
@client.event
async def on_message(message):    
    clearMessage = re.sub('[^A-Za-z0-9]+', '', message.content))
    clearMessage = clearMessage.replace(" ","")

    for bad_word in bad_words:
        if bad_word in clearMessage:
            t = discord.Embed(color=0x039e00, title="Message Removed", description=":x:   Please do not swear. Swearing can result in a mute or ban.")
            t.set_footer(text="DM TheSuperRobert2498#2498 for bot suggestions.")
            await message.channel.send(embed=t)
            await message.delete()
            return

    if not check_if_allowed(message.content):
        t = discord.Embed(color=0x039e00, title="Message Removed", description=":x:  Please do not swear. Swearing can result in a mute or ban.")
        t.set_footer(text="DM TheSuperRobert2498#2498 for bot suggestions.")
        await message.channel.send(embed=t)
        await message.delete()
        return

You don't necessarily need to split your message into all words. The if something in something statement can also search raw strings

it works, but if there is an uppercase letter in the message it does not block it. Is there something wrong with the code? I looked over it, but from what I saw there wasn't anything wrong with it. — TheSuperRobert, Jan 17 '21 at 02:09
then please replace `clearMessage = re.sub('[^A-Za-z0-9]+', '', message.content))` with `clearMessage = re.sub('[^A-Za-z0-9]+', '', message.content)).lower()`. — Timinator, Jan 17 '21 at 08:34

How to delete words that do not match exactly the black list due to additional characters in the word?

2 Answers2