import discord

client = discord.Client()

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

    if message.content.startswith('!hello'):
        msg = 'Hello {}!'.format(message.author.mention()
        yield from client.send_message(message.channel, msg))

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

client.run('email', 'password')