title: Override dict class?
body: <p>I'm trying to override <code>dict</code> class in a way that is compatible with standard <code>dict</code> class. How I can get access to parent <code>dict</code> attribute if I override <code>__getitem__</code> method?</p>
  <pre><code>class CSJSON(dict):
      def __getitem__(self, Key : str):
         Key = Key + 'zzz' # sample of key modification for app use
         return(super()[Key])
  </code></pre>
  <p>Then I receive error:</p>
  <pre><code>'super' object is not subscriptable.
  </code></pre>
  <p>If I use <code>self[Key]</code> then I get infinite recursive call of <code>__getitem__</code>.</p>