Find names of top-n highest-value columns in each pandas dataframe row

Question

I have the following dataframe:

  id     p1 p2 p3 p4
  1      0  9  1  4
  2      0  2  3  4
  3      1  3 10  7
  4      1  5  3  1
  5      2  3  7 10
         


        

Answer 1

You can use:

df = df.set_index('id').apply(lambda x: pd.Series(x.sort_values(ascending=False)
       .iloc[:3].index, 
      index=['top1','top2','top3']), axis=1).reset_index()
print (df)
   id top1 top2 top3
0   1   p2   p4   p3
1   2   p4   p3   p2
2   3   p3   p4   p2
3   4   p2   p3   p4
4   5   p4   p3   p2