I would wait until he completes his shed. Often times, they'll defecate at the same time. So leave him alone - nice and quiet and stress free and wait until he's finished. Then it's your call - wait a couple of days and offer food or a day or whenever....but I would definately wait until after the shed. 2 weeks isn't long for a ball python and most wont eat during a shed cycle anyways.
All the best with your new guy :-)