title: python tkinter Listbox bind with items updated
body: <p>I have a python GUI made with tkinter and I want to define a callback method to be called when the items in a listbox change:</p>
  
  <ol>
  <li>Item added to the listbox</li>
  <li>Item deleted from the listbox</li>
  </ol>
  
  <p>I think that should be possible with bindings but I am not sure what is the exact binding name. </p>