def columnitas(pal1, pal2):
    if len(pal1) != len(pal2):
        maslargo = max(len(pal1), len(pal2))
        pal1 = pal1.ljust(maslargo)
        pal2 = pal2.ljust(maslargo)

    for a,b in zip(pal1, pal2):
        print a, b

columnitas("Hola", "mundo")