title: How to unpack pkl file?
body: <p>I have a pkl file from MNIST dataset, which consists of handwritten digit images.</p>
  
  <p>I'd like to take a look at each of those digit images, so I need to unpack the pkl file, except I can't find out how.</p>
  
  <p>Is there a way to unpack/unzip pkl file?</p>