[Question]: sort_direct = -1 if condition_in_question == "none" else 1

Describe the issue

I have a question about the control_sentence_budget
In the functions:
def get_distance_longllmlingua(corpus, query):
context_ppl = [
self.get_condition_ppl(
d,
query
+ " We can get the answer to this question in the given documents.",
condition_in_question,
)
- dl * 2 / 250 * 0
for d, dl in zip(corpus, context_tokens_length)
]
sort_direct = -1 if condition_in_question == "none" else 1
ys = sorted(enumerate(context_ppl), key=lambda x: sort_direct * x[1])
return ys
and in the function
def control_sentence_budget()
......
sort_direct = -1 if condition_in_question == "none" else 1
sent_sort = sorted(
enumerate(sentence_ppl), key=lambda x: sort_direct * x[1]
)
Why is the sorting order of sent_sort in ascending order when condition_in_question is not "none"? Does this mean that when considering the question, sentences with lower perplexity are selected? But shouldn't sentences with higher perplexity be retained instead?Thanl you!