title: Mapping user site to their own url in a web.py application
body: <p>I'm coding a web app with web.py allowing users to add some html pages.</p>
  
  <p>Currently, the pages are mapping like that:</p>
  
  <pre><code>webapp.com/user1/page1
  webapp.com/user1/page2
  webapp.com/user2/page1
  webapp.com/user3/page1
  </code></pre>
  
  <p>I know web.py can manage subdomains to have:</p>
  
  <pre><code>user1.webapp.com/page1
  user2.webapp.com/page2
  ...
  </code></pre>
  
  <p>If the user would like his pages to appear under a custom domain URL that he control, such as www.user-own-url.com, I would like to give him the option.</p>
  
  <p>Is it possible to do it with web.py? Or is there another python solutions to do that?</p>