title: Which method can I override for cleanup task when a Tkinter.Tk window in Python?
body: <pre><code>class MainGUI(Tkinter.Tk):
      # some overrides
  
  # MAIN 
  
  gui = MainGUI(None)
  gui.mainloop()
  </code></pre>
  
  <p>But I need to do some cleanup when the window is closed by the user.  Which method in Tkinter.Tk can I override?</p>