'2' '11' '234' '1234' '12345' '2' '11' '234' '1234' '12345' 2’ 0000 00011’ 00234’ 01234’ ‘12345’ '00002' '00011' '00234' '01234' '12345' x np.char.zfill(x, 5) One digit Two digit Three digit Added zeros on left Numeric string of 5 digits with zeros: Four digit Five digit w3resource.com