[Python-Dev] Optimizing list.sort() by checking type in advance

[Guido van Rossum]

So maybe someone should explain to Elliott *why* his own benchmarks
are not trustworthy, rather than just repeat "use perf or timeit".
Actually, there are two things: (a) when something new comes along it
*always* needs to prove beyond a shadow of a doubt that it is actually
an improvement and not a timing artifact or a trick; (b) you can't
time sorting 10 values *once* and get a useful result. You have to do
it many times. And you have to make sure that creating a list of 10
random values isn't taken as part of your test -- that's tricky since
random() isn't all that fast; but it has to be done.

Although Elliott had it coming when he used needlessly offensive
language in his first post.

On Mon, Oct 10, 2016 at 5:09 PM, Steven D'Aprano <steve at pearwood.info> wrote:
> On Mon, Oct 10, 2016 at 09:16:32PM +0000, Elliot Gorokhovsky wrote:
>
>> Anyway, benchmarking technique aside, the point is that it it works well
>> for small lists (i.e. doesn't affect performance).
>
> You've been shown that there is something suspicious about your
> benchmarking technique, something that suggests that the timing results
> aren't trustworthy. Until you convince us that your timing results are
> reliable and trustworthy, you shouldn't be drawing *any* conclusions
> about your fastsort versus the standard sort.
>
>
> --
> Steve
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--Guido van Rossum (python.org/~guido)