title: Arranging columns in pivot_table, Pandas
body: <p>I have a question regarding rearrangement of the columns in a pivot_table. I want to group  columns by month, but with the arrangement as follows:</p>
  
  <pre><code>JAN      FEB  
  X,Y,X/Y  X,Y,X/Y ....
  </code></pre>
  
  <p>The current output is:</p>
  
  <pre><code>JAN FEB      JAN  FEB    JAN ...
  
  X   X   ...  Y     Y ...  X/Y ...
  </code></pre>
  
  <p>I've noticied the same behavior implemented in Excel when building a pivot table with multiple columns.</p>
  
  <p>See an example below. The output has the first format.
  Thanks</p>
  
  <pre><code>from pandas import DataFrame,pivot_table
  import numpy as np
  from datetime import datetime 
  
  names=["a","b","c","a","b"]
  dates=["20/01/2013","21/01/2013","22/02/2013", "01/03/2013","01/03/2013"]
  dico={"x":[1,3,5,7,9], "y":[2,4,6,8,10], "date":dates, "name":names}
  
  df=DataFrame(dico)
  df["month"]=[datetime.strptime(x,'%d/%m/%Y').month for x in dates ]
  
  print df
  mpivot=pivot_table(df, values=["x","y"],cols=["month"], rows="name",aggfunc=np.sum)
  print mpivot
  </code></pre>