title: Script does not filter swear words discord py
body: <p>I`m trying to create my discord.py bot to delete messages with swear words and, after that make an announcement who made that and abuse him for his behaviour. I load a bad words list in .txt File looks like: 'Badword, badword2, etc' </p>
  
  <p>i`ve tried many ways but i really do not get how to do that.</p>
  
  <p><a href="https://i.stack.imgur.com/JfgzP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JfgzP.png" alt="enter image description here"></a></p>
  
  <pre><code>import discord
  from discord.ext import commands,tasks
  import datetime 
  from itertools import cycle
  import os
  
  bot = commands.Bot(command_prefix = '/')
  
  with open('badwords.txt','r') as file:
      bad_words = [bad_word.strip(', ').lower() for bad_word in file.read()]
  
  @bot.event 
  async def on_message(message):
       if any(bad_word in message.content.strip().lower() for bad_word in bad_words):
             await message.channel.send(f"{message.author.mention}, твое сообщение не прошло цензуру")
             await message.channel.purge(limit=1)
             await bot.process_commands(message)
  </code></pre>
  
  <p>The bot calls himself too much, looks like it is recursive or smth!
  he reacts not only on bad words but on good ones too.</p>