title: How to wrap a python dict?
body: <p>I want to implement a class that will <em>wrap</em> -- not subclass -- the python <code>dict</code> object, so that when a change is detected in a backing store I can re-create the delegated dict object. I intend to check for changes in the backing store each time the dict is accessed for a read.</p>
  
  <p>Supposing I was to create an object to act like this; what methods would I need to implement?</p>