title: How to unzip/decompress a *.z file
body: <p>I have a file called pack.z which contains a few file. I want to unzip/decompress this pack.z file into a folder named *./pack using a python script. <br>
  I have tried using zipfile module, but it throws an error <strong>"zipfile.BadZipfile: File is not a zip file"</strong><br>
  So I am looking for a method to unzip this file. Any help would be great. </p>