There are three species.
Borneo short-tailed pythons (aka "Borneo blood python" )are found only on the island of Borneo (this includes Kalimantan, Sarawak, Sabah and probably Brunei.) There is some potential for confusion because Sarawak is part of the country of Malaysia and is also referred to as East Malaysia.
Sumatran short-tailed pythons (aka "black bloods" ) are found only on Sumatra. Sumatra is a large long island that has a mountain range that divides it into a west side and an east side. Sumatran short-tailed pythons are found on the west side of the island and in the south.
Blood pythons (aka "red bloods", "Sumatran bloods," "Malaysian bloods" and other combinations of names) are found on the east side of Sumatra and on the southern 2/3 of the Malay Peninsula, and on many of the islands in-between in the Straits of Malacca.
Blood pythons are not rare in West Malaysia, but they are today uncommon in captivity because neither Malaysia nor Thailand export the species (not in significant numbers, anyway.) Essentially all of the blood pythons available for sale in the US today are descended from animals collected in central eastern Sumatra.
"Red blood python" is a redundant common name usually used to distinguish the species from the "black blood" or the "Borneo blood" All three of those names are incorrect and down the road lead to further confusion.