title: How do I get the id of a mentioned user in a discord.py message?
body: <p>I'm making a discord bot with discord.py. How do I get the ID of a user mentioned in a message?</p>
  
  <p>For example, if someone types  <code>Hello @user</code></p>
  
  <p>The bot would detect the <code>@user</code> and find the id of that user.</p>