The difference between southern and northern white lipped pythons is both in color and size. The southern white lipped python is significantly larger, with the southern white lipped pythons being the ones tipping the scales at 8-9 ft in length. They also tend to be a great deal duller and darker than their northern counterparts. More often than not, you find northern white lipped pythons in the pet trade. If you are uncertain as to the exact species that you are looking at, ask the vendor or breeder. If they cannot tell you which variety the snake is, do not purchase it. Though care is similar between all of the white lipped python genus, temperament is not and you are entitled to know which temperament you are getting.