title: Associate files with specific extension to my own application in Python
body: <p>I have created an app. It uses some database file to show its contents in a wxpython frame.
  Let us assume the database file extension is .xyz. When I double-click on an .xyz file, I want to open that file in my application and call a function inside my app to process it. How can I do it in Python and in Windows.</p>
  
  <p>Thanks in advance.</p>