Why would you need one? To humidify a whole room to the amount you need for a ball python you're at risk of mold issues on your walls. (Unless you've purposely treated your walls to prevent water damage)

You should increase humidity of your tanks/tubs, not the room. There are many easier ways to do this, look at the care sheets.

For tanks you can mist the area, keep a towel over the tank, move to tubs.
In tubs you shouldn't have much of an issues at all.