What's really need with twins is when only one egg comes out and you have this nice multi-gene clutch. It's been documented that even though the one baby comes out shows on phenotype, hidden genes may exist in the snake through the sibling DNA that was absorbed. It's been documented in Carpet pythons, so its very well possible with other python species :-)

As far as identical goes, it has been documented fairly well that twins in pythons are genetically identical, but patterns may not be phenotypically identical. They will both generally be the same sex, and same morph. On the other side of the story . . . there is some evidence that suggest twins bred lead to higher chances of twins in their future clutches. While its not understood how it may or may not be heritable. It has been shown when Nick Mutton held back a pair of twins, bred them, and then I think one of their clutches ended up with a set of twins and triplets!

Congrats :-)