title: Decode one-hot dataframe in Pandas
body: <p>I have 2 dataframes with the data as below:</p>
  
  <pre><code>df1:
  ====
  id   name   age   likes
  ---  -----  ----  -----
  0     A      21    rose
  1     B      22    apple
  2     C      30    grapes
  4     D      21    lily
  
  df2:
  ====
  category    Fruit   Flower 
  ---------  -------  -------
  orange      1        0
  apple       1        0       
  rose        0        1
  lily        0        1
  grapes      1        0
  </code></pre>
  
  <p>What I am trying to do is add another column to df1 which would contain the word 'Fruit' or 'Flower' depending on the one-hot encoding in df2 for that entry.
  I am looking for a purely pandas/numpy implementation. </p>
  
  <p>Any help would be appreciated.</p>
  
  <p>Thanks!</p>