Any source of heat needs to be on a controller. There's rheostats which are basically lamp dimmers, control current-not very accurate or controllable and will vary with temps around it so if you run lamps you need to keep very on top of temps in there. Rheostats are decent for running a ceramic heat emitter but I would get something more controllable and accurate for a heat mat. Most light emitting heat bulbs aren't controllable with dimmers and will just burn out quickly but ball pythons don't like or need lights so I'd steer clear of them entirely. Then there's on/off thermostats, get up to temp at full power, shut off, turn back on when temps drop. These are good for running oil filled heaters but not ideal for heat sources like radiant heat panels or flexwatt or UTH if you want to keep a steady temp. Proportional thermostats are great for those, keeping temps steady and constantly adjusting as needed without running full power or shutting on/off all the time. Personally I use pvc cages with flexwatt and radiant heat panels controlled by a herpstat thermostat. My advice is don't go cheap when it comes to the most important thing for your snakes health.