Bad Discord Bot

import discord

def execute(code):
    res = {}
    try:
        exec(code,{},res)
    except Exception as e:
        return str(e)
    return str(res)

client = discord.Client()

@client.event
async def on_message(message):
    # we do not want the bot to reply to itself
    if message.author == client.user:
        return

    if message.content.startswith('!exec'):
        msg = execute(message.content[6:])
        await client.send_message(message.channel, msg)

@client.event
async def on_ready():
    print('Logged in as')
    print(client.user.name)
    print(client.user.id)
    print('------')

client.run('token')