I don't know what kind of python you have. Pythons fill many niches in nature, from deserts to tropical jungles. Most pythons that require high humidity aren't in the hands of folks who wouldn't already know how to solve that problem. So here's a couple of easy solutions...
Give the snake a hide box made of plastic that he can crawl down into. Put some damp substrate in there like peat moss or cypress mulch or whatever. This little hide will create a dark and humid place for the snake to relax. This will give him a humid micro-climate and he'll be fine.
Get rid of the screen top and get the snake in a cage designed for snakes. These usually restrict most of the airflow and allow for higher humidity in the cages.
Place a really large water dish in the cage. Something the snake can crawl into and move around. This will also raise the humidity.
Good luck.
Doug T