```python
#!/usr/bin/python3
# DELETE ALL MESSAGEZ
# BY bisti

import asyncio
import discord
import re

c = discord.Client()
token = "YOUR_TOKEN"
channel_id = "CHANNEL_ID"
deleted = 9999

@c.event
async def on_ready():
    welcome = "Logged in as {0.name} - {0.id}".format(c.user)
    print(welcome)
    print("Trying to delete all messages in " + channel_id + " from username " + c.user.name)
    async for m in c.logs_from(c.get_channel(channel_id),limit=deleted):
        try:
            if m.author == c.user:
                await c.delete_message(m)
        except: pass
    print (str(deleted) + " messages were deleted")
c.run(token, bot=False)
```