你如何根据第二个“列”对 python 中 1.72e+10 个元素的生成器类型进行排序？

Question

I have a generator object containing 2 "columns" and 1.72e+10 "rows". I want to sort the generator object according to the second column, using sorted like this takes an insane amount of time. I don't know if it makes sense to talk about columns and rows in generators, but I use quotations marks as I don't know what else to call it.

sorted_list = sorted(list(generator_obj),
                     key=lambda x: x[1], 
                         reverse=True)

Is there any smart way of sorting a huge generator object quickly? I don't have a computer science background, so I guess I am also wondering if it is inevitable to spend a huge amount of time on sorting such a large object? Also I believe it is faster to convert the generator_obj before supplying it as an argument for sorted() , which is why I don't submit a raw generator.

I have also tried to sort in place with the same results as above:

list(generator_obj).sort(key=lambda x: x[1], reverse=True)

Answer 1

Sorting requires ~N log N time, if all you have is a comparison function.

If your keys are integers, you can sort in ~ N time using the radix sort .

Either way, sorting a "huge" sequence requires "huge" time.