title: Pandas dataframe - column transpose
body: <p>given the dataframe</p>
  
  <pre><code>user month      valueX   valueY
  --------------------------------
  884  2013-01    1        5
  889  2013-02    0        15
  884  2013-02    7        29
  889  2013-01    9        38
  </code></pre>
  
  <p>how can I get to this one:</p>
  
  <pre><code>user |2013-01-valueX |2013-02-valueX  |2013-01-valueY  |2013-02-valueY
  --------------------------------------------------------------------
  884  |1              |7               |5               |19
  889  |9              |0               |38              |15
  </code></pre>