Did you clean and replace the substrate in the snake's cage? You can always give your snake a soak in luke warm water for about 15 minutes (supervised) but that really is unnecessary. Most times it is the enclosure that is causing the odor not the snake.All you need to do for a snake is take a mildly damp paper towel and wipe the snake down to remove any waste on it.
Make sure you disinfect the cage. Ball pythons should not smell normally. If the cage is fouled or bacteria have started to grow you can get an odor but as for a foul odor, that is pretty uncommon in a healthy snake.