[Python-Dev] Python 3.6 dict becomes compact and gets a private version; and keywords become ordered

[Maciej Fijalkowski]

On Thu, Sep 15, 2016 at 1:27 PM, Paul Moore <p.f.moore at gmail.com> wrote:
> On 15 September 2016 at 10:43, Raymond Hettinger
> <raymond.hettinger at gmail.com> wrote:
>> Something like this will reveal the true and massive improvement in iteration speed:
>>
>>      $ ./python.exe -m timeit -s "d=dict.fromkeys(map(str,range(10**6)))" "list(d)"
>
>>py -3.5 -m timeit -s "d=dict.fromkeys(map(str,range(10**6)))" "list(d)"
> 10 loops, best of 3: 66.2 msec per loop
>>py -3.6 -m timeit -s "d=dict.fromkeys(map(str,range(10**6)))" "list(d)"
> 10 loops, best of 3: 27.8 msec per loop
>
> And for Victor:
>
>>py -3.5 -m perf timeit -s "d=dict.fromkeys(map(str,range(10**6)))" "list(d)"
> ....................
> Median +- std dev: 65.7 ms +- 3.8 ms
>>py -3.6 -m perf timeit -s "d=dict.fromkeys(map(str,range(10**6)))" "list(d)"
> ....................
> Median +- std dev: 27.9 ms +- 1.2 ms
>
> Just as a side point, perf provided essentially identical results but
> took 2 minutes as opposed to 8 seconds for timeit to do so. I
> understand why perf is better, and I appreciate all the work Victor
> did to create it, and analyze the results, but for getting a quick
> impression of how a microbenchmark performs, I don't see timeit as
> being *quite* as bad as Victor is claiming.
>
> I will tend to use perf now that I have it installed, and now that I
> know how to run a published timeit invocation using perf. It's a
> really cool tool. But I certainly won't object to seeing people
> publish timeit results (any more than I'd object to *any*
> mirobenchmark).
>
> Paul

How about we just make timeit show average and not disable the GC then
(two of the complaints that will not change the execution time)?