title: python whois library return nothing for active domain names
body: <p>I am trying to use python whois library to gather whois records of some web sites.</p>
  
  <p>The problem is that I got nothing for some web sites such as nih.gov which is an active domain name!</p>
  
  <pre><code>w = whois.whois("nih.gov")
  print w
  {u'updated_date': None, u'status': u'ACTIVE', u'name': None, u'dnssec': None, u'city': None, u'expiration_date': None, u'zipcode': None, u'domain_name': u'NIH.GOV', u'country': None, u'whois_server': None, u'state': None, u'registrar': None, u'referral_url': None, u'address': None, u'name_servers': None, u'org': None, u'creation_date': None, u'emails': None}
  </code></pre>
  
  <p>I can not understand what is the problem and which library or how should I use to cover all situations?</p>