I would suggest the answer is posting the question should be based on how fast you'll get a answer, the quality of the answer, and the breadth of knowledge of those answering the question, for follow up.
The problem is that I am not sure where that is. I think that discovering the best place to ask the question is to search for similar questions an look at the quality of those responses. I just happened to notice the same post on SFServer Fault 80227 and SOStack Overflow 1655932 asking about PYTHONPATHPYTHONPATH. I'll let someone else judge the quality of the two answers.