我正在尝试使用discord.py编写一个简单的机器人，所以我从有趣的命令开始，例如只是为了获得api的优势。

import discord
import asyncio
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('!hug'):
        await client.send_message(message.channel, "hugs {0.author.mention}".format(message))

    # Greetings
    if message.content.startswith('hello'):
        msg = 'Hello {0.author.mention}'.format(message)
        await client.send_message(message.channel, msg)

    # say (id) is the best
    # This is where I am lost. how to mention someone's name or id ?
    if message.content.startswith('!best'):
        mid = User.id('ZERO#6885').format(message)
        await client.send_message(message.channel, '{mid} mentioned')