Discord py obtenga el usuario por identificación
user = bot.get_user(user_id)
IllegalBeagle123
user = bot.get_user(user_id)
username = client.get_user(user_id)
user = await bot.fetch_user(payload.user_id)
#Another way to do it as a simpler way with discord.py:
#(This is a command for showing the author of the message's ID)
id = message.author.id
if message.content.startswith("!whatismyid"):
await message.channel.send("Your ID is: "+str(id))
id = message.author.id
await message.channel.send("<@"+str(id)+"> Mentioned you!")