Answer:
You have nobody, don't you? or
Step-by-step explanation:
It wouldn't be don't you have nobody? because technically without contractions it would mean do you not have nobody?, which is a double negative sentence, which is grammatically incorrect. So, 'You have nobody, don't you? means the same thing as 'You have nobody, do you not?, which is grammatically correct because it isn't a double negative like the first one. It's stating that you have nobody, and then asking if that statement is correct.