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Comment by Timja | Hacker News Reader

Javascript being 41x faster than Python seems a bit excessive.

In my experience, having done quite a lot of dynamic language benchmarks, Javascript is about as fast as PHP and both are about 6x faster than Python.

Has someone looked at the Python code used here, if it has any obvious gotchas?

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There is one. The author's implementation of `combinations` runs in quadratic time making copies of lists on each iteration. I replaced that for `itertools.combinations`, which uses an iterator, and found a pretty big difference:

     ~/p/not_that_slow  python3.11 modified.py 5000000
    -0.169075164
    0.183753791
    Time: 6.335 s

     ~/p/not_that_slow  python3.11 main.py 5000000
    -0.169075164
    -0.169083134
    Time: 48.515 s

Other than this, the only modification I made is to include a `print` statement at the end to show the time taken.

EDIT: That is not actually equivalent, my bad. The iterator is consumed and the execution ends early, I didn't realize the algorith iterated over it multiple times.

how're you using it? what you printed out (modified.py) seems to be a different result than expected

Heavy list creation is one way to really slow down Python.

And itertools is a real gem, full of lots of goodies to handle list manipulation tasks.

It’s a benchmark that is basically the ideal case for a JIT so it’s really Python vs. JS that got native compiled.

I’m in no way criticizing the benchmark but that’s the reason for the starker difference.

let me know if you find anything! Happy to edit the post with a correction.

For a little more information, this is using Bun 0.2.1, which uses JavaScriptCore (JSC), a part of WebKit which powers Safari. Since I'm running on an M1 Pro (Apple's ARM chip), there is probably somewhat of a benefit in using JSC.

It's not excessive in my experience. Javascript is usually very fast. Much faster than PHP and Phython.

There are many flaws in this benchmark but the order of magnitude looks right to me: https://benchmarksgame-team.pages.debian.net/benchmarksgame/...

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