title: access value of a python dict() without knowing the keys
body: <p>I have a dictionary of a list of dictionaries. something like below:</p>
  
  <p><code>x = {'a':[{'p':1, 'q':2}, {'p':4, 'q':5}], 'b':[{'p':6, 'q':1}, {'p':10, 'q':12}]}</code></p>
  
  <p>The length of the lists (values) is the same for all keys of dict x.
  I want to get the length of any one value i.e. a list without having to go through the obvious method -> get the keys, use len(x[keys[0]]) to get the length.</p>
  
  <p>my code for this as of now:</p>
  
  <pre><code>val = None
  for key in x.keys():
      val = x[key]
      break
      #break after the first iteration as the length of the lists is the same for any key
  try:
      what_i_Want = len(val)
  except TypeError:
      print 'val wasn't set'
  </code></pre>
  
  <p>i am not happy with this, can be made more 'pythonic' i believe. </p>