The good news is that is a ball python. A Milk Snake would have already rented a car, booked a plane ticket and be half-way back to its country by now....
Ball python playbook: First day of escape---Hide ASAP somewhere dark and don't move until you are hungry!
-Imagine a fifteen foot radius around his tank, now check every nook and cranny (even really small ones that seem physically impossible to get into). If you have a hole in the wall nearby or radiator pipes that have gaps through the floor--that is bad news.
-They are also adept climbers-so don't forget to check elevated spots that they can wedge their body into (e.g. behind books on a shelf, inside clothes on a hanger, on the upper top edge of a cabinet etc)...