title: Redirection url using urllib in Python 3
body: <p>I would need to know what is my final URL when following redirections using urllib in Python 3.</p>
  
  <p>Let's say I've some code like :</p>
  
  <pre><code>opener = urllib.request.build_opener()
  request = urllib.request.Request(url)
  u = opener.open(request)
  </code></pre>
  
  <p>If my urls redirects to another website, how can I know this new website URL ? I've found nothing useful in documentation.</p>
  
  <p>Thanks for your help !</p>