title: How to detect if any element in a dictionary changes?
body: <p><strong>Rather than saving a duplicate</strong> of the dictionary and comparing the old with the new, alike this:</p>
  
  <pre><code>dict = { "apple":10, "pear":20 }
  
  if ( dict_old != dict ):
     do something
     dict_old = dict
  </code></pre>
  
  <p><strong>How is it possible to detect WHEN any element of a dictionary changes?</strong></p>