The ball python won't be any real risk to either your cats or pugs. Newly born kittens or pups cuold be eaten by the ball python but such animal young are not a natural diet for ball pythons. However both the snake and furry animals can be injured if any 'incident' happens. Dog bites, cat bites and scratches can harm a ball python, either in severety or infections.
Keep your cats and dogs away from teh ball python when it is out of it's cage. Make sure the python cage is secure and able to withstand the weight of your cats jumping ontop. In fact, it would be better, if possible to have the ball python in it's separate room, then you can raise the room temp at night with a separate heater to stay around 70-75F.
Oh one other thing, in regards to a question you had in your earlier post. I would avoid hanlding the new python for at least a couple successful feedings, to make sure it is well and setttled in it's new home. After than you can take him out for short periods (5-10 minutes) gradually increasing this time but stop handling if the snake shows any signs of stress.