title: proper way to subclass object for __getitem__() in python if emulating a dict
body: <p>What's the proper way to subclass <code>object.__getitem__()</code> but fall back on the default behavior? I want to make this look like a dict that behaves dynamically (but consistently) for any possible key.</p>
  
  <pre><code>class MyObj(object):
      """MyObj()[k] returns 1 for any key k that ends in '_q',
         default item lookup behavior otherwise"""
      mypattern = re.compile(r'_q$')
      def __getitem__(self, k):
          if self.mypattern.match(k):
              return 1
          else:
              ???
  </code></pre>
  
  <p>I tried calling <code>return super(TFConverter, self).__getitem__(k)</code> and it tells me <code>AttributeError: 'super' object has no attribute '__getitem__'</code></p>