title: How to quickly fail a python script if it is called from wrong interpreter?
body: <p>I have inherited a few Python scripts from someone who has left my employer. Some are meant to be run from Jython, others are not. </p>
  
  <p>I'd like to add them to svn, but before I do I want to modify these files so that if a "requires Jython" file is run from python, the user gets a message like "please run with Jython" and the program exits.  </p>
  
  <p>(Warning: I am not very familiar with Python/Jython.)  </p>
  
  <p>I expect the simplest way to do this is create a file <code>require-jython.py</code> with the contents like:</p>
  
  <pre><code>if runtime.name !=  'jython'
    print "Please run with Jython"
    exit(1) 
  </code></pre>
  
  <p>and then "include/require"? this file (again I'm not an expert. bear with me here)</p>
  
  <p>Can anyone spell out the steps for me?</p>