title: Invalid URL: No host supplied : error while using Request.get(url) in Python
body: <p>Code:</p>
  
  <pre><code>img=requests.get('http:////files.explosm.net/comics/Rob/chainsaw.png')
  </code></pre>
  
  <p>Error Message:</p>
  
  <pre><code>requests.exceptions.InvalidURL: Invalid URL u'http://files.explosm.net/comics/Rob/chainsaw.png': No host supplied
  </code></pre>
  
  <p>What's wrong with the url? 
  files.explosm.net/comics/Rob/chainsaw.png</p>