Use the lower() method to map character values to lowercase.
Example Setup
>>> df = DataFrame('sales')
>>> df
Feb Jan Mar Apr datetime accounts Alpha Co 210.0 200 215 250 04/01/2017 Red Inc 200.0 150 140 None 04/01/2017 Orange Inc 210.0 None None 250 04/01/2017 Jones LLC 200.0 150 140 180 04/01/2017 Yellow Inc 90.0 None None None 04/01/2017 Blue Inc 90.0 50 95 101 04/01/2017
Example 1
>>> df.assign(drop_columns = True, lower = df.accounts.str.lower())
lower 0 alpha co 1 red inc 2 orange inc 3 jones llc 4 yellow inc 5 blue inc
Example 2
>>> df[df.accounts.str.lower() == 'orange inc']
Feb Jan Mar Apr datetime accounts Orange Inc 210.0 None None 250 04/01/2017