title: Find minimum element in a dictionary of dictionaries
body: <p>I need to find what element of <code>apple</code> has the minimum <code>size</code>.</p>
  
  <p>Tnx for all answers. But there is one problem: I use Python 2.4.2 (I can't change it) and function <code>min</code> haven't <code>key</code> arg. Yes, I need key of <code>apple</code></p>
  
  <pre><code>apple = {1:{'size':12,'color':'red'},2:{'size':10,'color':'green'}}
  </code></pre>