title: Extracting a zipfile to memory?
body: <p>How do I extract a zip to memory?</p>
  
  <p>My attempt (returning <code>None</code> on <code>.getvalue()</code>):</p>
  
  <pre><code>from zipfile import ZipFile
  from StringIO import StringIO
  
  def extract_zip(input_zip):
      return StringIO(ZipFile(input_zip).extractall())
  </code></pre>