title: How to show all the element names in a npz file without having to load the completely?
body: <p>I use the following code to show the element names in a npz file. But it requires loading the file completely, which can be slow especially when the file is large. Is there a way to extract the element names without having to load the file completely?</p>
  
  <pre><code>x = numpy.load(file)
  for k in x.iterkeys():
      print k
  </code></pre>