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nan
this is about the correct name of the pythons in Southern Africa, and all I can tell you is that there is no such a thing as a correct name, because the naming depends on your (or scientist's) opinion about a python in Southern Africa.
Most (as your "specialist") think, the pythons in Southern Africa are different to pythons in central and west Africa and say they are two species: Python sebae (some call it Northern or Central African Python, others call it African Rock Python) in central and west Africa and Python natalensis (Southern African Python) in the South and East.
Other specialists think, they are all one species Python sebae and call them African Rock Python. This "African Rock Python" is divided into two subspecies, P. s. sebae (the nominate subspecies) and P. s. natalensis (the Southern African rock python).
If somebody says there is no African Rock Python in South Africa or Namibia, he should explain why.
If you support the older taxonomic idea, there is a "African Rock Python" in South Africa or Namibia.
So how do we decide if the southern pythons are a separate species or only a subspecies? That depends on your understanding of a "species" and there are many different opinions.
Most species concepts say a species is different from another when they do not (or can not) succesfully interbreed.
For the pythons in Africa:
The existence of sympatric populations of the two taxa Python sebae and P. natalensis in northeastern Tanzania provides evidence for the validity of P. natalensis (Broadley 1999), however possible hybrids with intermediate characters are known from this region
Sympatric populations means boths pythons occur in the same area in Tanzania and you can still distinguish them. But they can interbreed and there are a few hybrids. This is why experts do not agree.
And the English (or any) common names (often there is more than one or the same name is applied to different species) are usually more confusing than the scientific Latin names, as you can see here.