I have 2 dogs, a cat, and 2 guinea Pigs. I want a Ball Python! How do I get my parents to get 1?

To be honest, you should be thankful for the pets you do have. I wouldn't be surprised about the fact your dad does not let you get another animal. You seem like a spoiled brat to me. You're lucky to even have all of those pets, now go and give your pets attention while they're still alive and stop thinking about what you don't have for once.