title: Python Dataframe new columns from dictionary
body: <p>I have a dictionary called pair_candidates. It is the co integration of various stocks. When I run:</p>
  
  <pre><code>for key, value in pair_candidates.iteritems():
      print key
      for i, x in value.iteritems():
          print i
          print x
  </code></pre>
  
  <p>yields: </p>
  
  <pre><code>GOOG
  Equity(26578 [GOOG_L])
  0.99474625176
  Equity(46631 [GOOG])
  1.0
  NEM
  Equity(154 [AEM])
  0.986407479901
  Equity(5261 [NEM])
  1.0
  USB
  Equity(25006 [JPM])
  0.976828428881
  Equity(25010 [USB])
  1.0
  CMA
  Equity(1620 [CMA])
  1.0
  Equity(8399 [ZION])
  0.982642475515
  Equity(25006 [JPM])
  0.980413261534
  AMAT
  Equity(337 [AMAT])
  1.0
  Equity(7671 [TXN])
  0.978239746926
  Equity(8677 [MCHP])
  0.978793774219
  </code></pre>
  
  <p>What I would like is a dataframe as follows please:
  <a href="https://i.stack.imgur.com/Ly0Am.png" rel="nofollow noreferrer">enter image description here</a></p>