title: Unknown encoding: idna in Python Requests
body: <p>I'm using Python Requests. All works great but today I get this strange error:   </p>
  
  <pre><code>[...]
  File "/usr/local/Cellar/python/2.7.2/lib/python2.7/site-packages/requests/models.py", line 321, in full_url
      netloc = netloc.encode('idna').decode('utf-8')
  LookupError: unknown encoding: idna
  </code></pre>
  
  <p>Any ideas what could be wrong? I'm using Python 2.7.2 from brew.</p>