I can only imagine that since a ball python consumes small mammals whole, which includes a large portion of fur, skin, bones, and other things that would never end up in our own digestive systems, it isn't surprising that they have such unusual excrement.
I am sure the OP will appreciate the answer 12 years later
As mentioned the so called white "poop" is in fact urate (a urine by product), poop well just looks like poop.