Find the column name which has the maximum value for each row

Question

I have a DataFrame like this one:

In [7]:
frame.head()
Out[7]:
Communications and Search   Business    General Lifestyle
0   0.745763    0.050847    0.118644         


        

Answer 1

You can use idxmax with axis=1 to find the column with the greatest value on each row:

>>> df.idxmax(axis=1)
0    Communications
1          Business
2    Communications
3    Communications
4          Business
dtype: object

To create the new column 'Max', use df['Max'] = df.idxmax(axis=1).

To find the row index at which the maximum value occurs in each column, use df.idxmax() (or equivalently df.idxmax(axis=0)).