title: Python: use the same class instance in multiple modules
body: <p>I have a class called EventManager, and am calling this class in each module I have. I thought  of creating a single instance of the EventManager in the main file, and use that instance in each module. My questions are:</p>
  
  <ul>
  <li>Is this the right way in my case? Note that I don't want to create multiple instances of the EventManager as it parses a file each time it is called, and that file can contain large amount of data.</li>
  <li>what is the best way to do it, given that I want less memory usage?</li>
  </ul>