Pandas: add a column to a multiindex column dataframe
It’s actually pretty simple (FWIW, I originally thought to do it your way): df[‘bar’, ‘three’] = [0, 1, 2] df = df.sort_index(axis=1) print(df) bar baz one two three one two A -0.212901 0.503615 0 -1.660945 0.446778 B -0.803926 -0.417570 1 -0.336827 0.989343 C 3.400885 -0.214245 2 0.895745 1.011671