Adding new column to existing DataFrame in Python pandas

Question

I have the following indexed DataFrame with named columns and rows not- continuous numbers:

          a         b         c         d
2  0.671399  0.101208 -         


        

Answer 1

Easiest ways:-

data['new_col'] = list_of_values

data.loc[ : , 'new_col'] = list_of_values

This way you avoid what is called chained indexing when setting new values in a pandas object. Click here to read further.