title: Search for a key in a nested Python dictionary
body: <p>I have some Python dictionaries like this: </p>
  
  <pre><code>A = {id: {idnumber: condition},.... 
  </code></pre>
  
  <p>e.g.</p>
  
  <pre><code>A = {1: {11 : 567.54}, 2: {14 : 123.13}, .....
  </code></pre>
  
  <p>I need to search if the dictionary has any <code>idnumber == 11</code> and calculate something with the <code>condition</code>. But if in the entire dictionary doesn't have any <code>idnumber == 11</code>, I need to continue with the <em>next</em> dictionary.</p>
  
  <p>This is my try:</p>
  
  <pre><code>for id, idnumber in A.iteritems():
      if 11 in idnumber.keys(): 
         calculate = ......
      else:
         break
  </code></pre>