Convincing Dad to Let Me Buy a Snake

First of all...

EVERYTHING SALLOS SAID !!!

I agree with every word, so no need to say it again.

Many pleasures in life are in all practicality "useless". Watching TV is useless. Sure, you "might" learn a bit, but truly. Mostly you just vegetate. However, it is our "down time". It gives us pleasure.
So while "useless", its still considered having a good time.
Taking a walk outside is "useless". You might loose a bit of weight, but other then that, its not a very productive "past time". Yet, that is how we can enjoy nature and relax, re-charge.

Owning pets is not useless. Even dogs and cats are not earning us money or washing dishes for us. Yet having them around gives us pleasure.

So what if a snake doesn't wag its tail when we come home or ask to be petted.

Tell you dad, love is selfless. You can enjoy and love a being without expecting something in return. I take real pleasure from my air plants. A new hobby. They are really fun to own and you can be creative with them. They don't wait by the door for me, but its still great fun to research them, take care of them, mount them in elaborate settings, etc etc. They are, much like reptiles, "Living Art".

Anything that keeps a persons mind and body occupied and interested isn't useless. And if you spend your time learning about natural science, taking care of it, you aren't spending it hanging out in the mall parking lot drinking beer. Or worse.

All that said, though...it is still your parents house and their rules.

Life flies by, before you know it, you will have MANY many years in which you make your own rules in your own place.
So if your dad will just not budge, look forward to the many snakes you'll have later in life ;)

You're not going to convince your dad that a snake is useful, because it's not going to pull a wagon or keep mice out of the barn or herd sheep or hunt pheasants or do your chores for you. Pets inherently aren't "practical" in that sense.
But they are certainly worth the trouble of having around, if you're the sort of person for whom they're worth it.

When I was a teenager my mom tolerated us having pets, but once we were out of the house she vowed to never take responsibility for another animal ever again. She gets it that other people like them, but won't ever be convinced that they're worth the trouble of having. My dad, on the other hand, is really an animal person and having them really makes a huge difference in his life. For him, there's no question about whether they're worth it. (They aren't together, if you were wondering!)

Probably the best argument is that a ball python is most of the time about as easy and undemanding of an animal as you can ask for, once the initial setup is taken care of. It will may also help to have a game plan for when you go to college or otherwise move out of the house and may not be able to take the snake with you; maybe a friend or relative who will agree to take the snake in for a year or two until you can care for it again, or a plan for re-homing it if necessary. In other words, assure your parents that they won't be on the hook for the snake's care if your life circumstances mean that you can't during college or whatever.