title: discord.py: Trying to wait for author response and answer it
body: <p>I'm currently trying to make a bot using discord.py, and I have a small problem: I don't know how to wait for the author response and for the bot to post another message after it.
  Here's my code for the moment:</p>
  <pre><code>import discord
  
  client = discord.Client()
  
  @client.event
  async def on_ready():
      print('We have logged in as {0.user}'.format(client))
  
  @client.event
  async def on_message(message):
  
      if message.author == client.user:
          return
  
      if message.content.startswith('.pdfcheckup'):
          await message.channel.send(&quot;Quelle matière scolaire cherchez-vous ?\nListe des matières disponibles:\n**```\n1- Histoire\n2- Géographie\n3- EMC\n4- Français\n6- Mathématiques\n7- Physique-Chimie\n8- Enseignement Scientifique\n9- NSI\n10- Anglais\n11- Espagnol\n12- Allemand\n```**&quot;)
  
  client.run('[my token]')
  </code></pre>
  <p>So, to sum what my bot needs to do, the author writes &quot;.pdfcheckup&quot;, the bot responds with the long message, the bot waits for the author to say a number between 1 and 12, and depending on the number the author picked, it answers with a special message. But I'm dumb to do this.</p>
  <p>Thank you.</p>