title: Python: sort this dictionary (dict in dict)
body: <pre><code>d = { 'a':{'k':1, 'b':'whatever'},  'b':{'k':2, 'b':'sort by k'} }
  </code></pre>
  
  <p>Want to sort this dictionary by k as descending order, in python.</p>
  
  <p>Little tricky, please help.</p>