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Speed up itertools.pairwise #118218

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hauntsaninja opened this issue Apr 24, 2024 · 1 comment
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Speed up itertools.pairwise #118218

hauntsaninja opened this issue Apr 24, 2024 · 1 comment
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extension-modules C modules in the Modules dir performance Performance or resource usage type-feature A feature request or enhancement

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@hauntsaninja
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hauntsaninja commented Apr 24, 2024 •
edited by bedevere-app bot
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The pairwise implementation mentions that we can reuse the result tuple

There's currently some discussion of performance ongoing at https://discuss.python.org/t/nwise-itertools/51718

Linked PRs
@hauntsaninja hauntsaninja added the type-feature A feature request or enhancement label Apr 24, 2024
@AlexWaygood AlexWaygood added performance Performance or resource usage extension-modules C modules in the Modules dir labels Apr 24, 2024
hauntsaninja added a commit to hauntsaninja/cpython that referenced this issue Apr 24, 2024
@hauntsaninja
pythongh-118218: Reuse return tuple in itertools.pairwise
3bd6a58 
With this change:
```
b1(1)            min=152.8us mean=155.5us ± 3.8us (25 repeats, 1000 loops)
b2(1)            min=149.0us mean=159.1us ± 8.8us (25 repeats, 1000 loops)
b3(1)            min=232.6us mean=242.5us ± 11.7us (25 repeats, 1000 loops)
b1(10)           min=279.2us mean=296.9us ± 16.6us (25 repeats, 1000 loops)
b2(10)           min=249.5us mean=259.2us ± 12.2us (25 repeats, 1000 loops)
b3(10)           min=386.6us mean=398.8us ± 10.1us (25 repeats, 1000 loops)
b1(1000)         min=20.3ms mean=20.7ms ± 0.5ms (25 repeats, 1000 loops)
b2(1000)         min=16.7ms mean=17.1ms ± 0.2ms (25 repeats, 1000 loops)
b3(1000)         min=26.0ms mean=26.2ms ± 0.3ms (25 repeats, 1000 loops)
```
Without this change:
```
b1(1)            min=142.2us mean=143.0us ± 0.9us (25 repeats, 1000 loops)
b2(1)            min=142.7us mean=143.3us ± 1.0us (25 repeats, 1000 loops)
b3(1)            min=219.8us mean=227.2us ± 4.4us (25 repeats, 1000 loops)
b1(10)           min=314.2us mean=323.8us ± 4.1us (25 repeats, 1000 loops)
b2(10)           min=335.4us mean=341.8us ± 5.1us (25 repeats, 1000 loops)
b3(10)           min=362.0us mean=386.2us ± 14.9us (25 repeats, 1000 loops)
b1(1000)         min=26.5ms mean=27.3ms ± 0.3ms (25 repeats, 1000 loops)
b2(1000)         min=29.8ms mean=30.2ms ± 0.2ms (25 repeats, 1000 loops)
b3(1000)         min=26.0ms mean=26.5ms ± 0.4ms (25 repeats, 1000 loops)
```
@bedevere-app bedevere-app bot mentioned this issue Apr 24, 2024
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@eendebakpt
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eendebakpt commented Apr 24, 2024 •
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Also see #118222 (improve performance of pairwise by replacing PyTuple_Pack)

serhiy-storchaka pushed a commit that referenced this issue Apr 30, 2024
@hauntsaninja
gh-118218: Reuse return tuple in itertools.pairwise (GH-118219)
6999d68
SonicField pushed a commit to SonicField/cpython that referenced this issue May 8, 2024
@hauntsaninja @SonicField
pythongh-118218: Reuse return tuple in itertools.pairwise (pythonGH-1…
ca6a36f 
…18219)
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