Python: The Optimization Ladder

While this is great, I expected faster CPython to eventually culminate into what YJIT for Ruby is. I'm not sure the current approaches they are trying will get the ecosystem there.

Now this is great to know.

Taichi, benchmarked in the article, claims to be able to outperform CUDA at some GPU tasks, although their benchmarks look to be a few years old:

https://github.com/taichi-dev/taichi_benchmark

Jax seems quite interesting even from this point of view… numpy has the same problem as blas basically, right? The limited interface. Eventually this leads to heresies like daxpby, and where does the madness stop once you’ve allowed that sort of thing? Better to create some sort of array language.

this is a pointless (valueless) reductive take

The dynamism exists to support the object model. That's the actual dependency. Monkey-patching, runtime class mutation, vtable dispatch. These aren't language features people asked for. They're consequences of building everything on mutable objects with identity.

Strip the object model. Keep Python.

You get most of the speed back without touching a compiler, and your code gets easier to read as a side effect.

I built a demo: Dishonest code mutates state behind your back; Honest code takes data in and returns data out. Classes vs pure functions in 11 languages, same calculation. Honest Python beats compiled C++ and Swift on the same problem. Not because Python is fast, but because the object model's pointer-chasing costs more than the Python VM overhead.

Don't take my word for it. It's dockerized and on GitHub. Run it yourself: honestcode.software, hit the Surprise! button.

I've always thought the flexibility should allow python to consume things like gRPC proto files or OpenAPI docs and auto-generate the classes/methods at runtime as opposed to using codegen tools. But as far as I know, there aren't any libraries out there actually doing that.

There are some use cases for very dynamic code, like ORMs; with descriptors you can add attributes + behavior at runtime and it's quite useful. Anyways, breaking metaprogramming and more dynamic features would mean python 4 and we know how 2 -> 3 went. I also don't think it's where the core developers are going. Also also, there are other things I'd change before going after monkey patching like some scoping rules, mutable defaults in function attributes, better async ergonomics, etc.

I've used a library that patches the zipfile module to add support for zstd compression in zipfiles.

In python3.14 the support is there, but 2 years ago you could just import this library and it would just work normally.

The author is from Turkey (where I’m also originally from).

Believe it or not, when you write a blog post in a different language, it really helps to use an LLM, even just to fix your grammar mistakes etc.

I assume that’s most likely what happened here too.

Here's what gave it away for me

> The remaining difference is noise, not a fundamental language gap. The real Rust advantage isn't raw speed -- it's pipeline ownership.

I didn't notice any signs of AI writing until seeing this comment and re-reading (though I did notice it on the second pass).

That said, I think this article demonstrates that focusing on whether or not an article used AI might be focusing on the wrong “problem.” I appreciate being sensitive to the "smell" (the number of low-effort, AI posts flying around these days has made me sensitive too), but personally, I found this article both (1) easy to read and (2) insightful. I think the number of AI-written content lacking (2) is the problem.

I also seem to be developing an immune response to several slopisms. But the actual content is useful for outlining tradeoffs if you’re needing to make your Python code go faster.

I have the same issue now. It's especially annoying when it happens while reading a "serious" publication like a newspaper or long form magazine. Whether it was because an AI wrote it or "real" writers have spent so much time reading AI slop they've picked up the same style is kinda by the by. It all reads to me like SEO, which was the slop template that LLMs took their inspiration from, apparently. It just flattens language into the most exhausting version of it, where you need to try to subconsciously blank out all the unnecessary flourishes and weird hype phrases to try figure out what actually is trying to be said. I guess humans who learn to ignore it might to do better in this brave new world, but it's definitely annoying that humans are being forced to adapt to machines instead of the other way around.

Fwiw, I thought the article is full of great information and well researched. I think your reflex is holding you back.

So much "is real". It is ok to check your grammar, but this is slopabetes inducing.

I had the same reflex. I just can't read AI redacted stuff. I don't know why it just reads very hollow and 'icky'

“The numbers are real.” But the voice is not.

I got the same sense, but nowadays I can't be sure whether a text is AI or the writer's style has absorbed LLM tropes.

If we only applied the same reflex to software, even when 100% human programmed.

What is the point of your post? I find it increasingly tedious to read comments about alledged AI use under almost every post. It's like complaining that you didn't want to read the submission because you didn't like their font or website design.

I think almost everyone here agrees they don't want to read AI slop, but this submission clearly wasn't that as you admit yourself.

I don't think it should be conflated with auto generated AI slop. I see a lot of snippets which were clearly manually written. I'm assuming the author used AI in a supervised manner, to smooth out the writing process and improve coherency.

I've checked some run times on my M1 mac mini, and have realised the C run time of 2.1s for n-body is the figure from the benchmark game itself, which is 50 million iterations on a very old i5. It would have made sense if they'd run the C version on their M4 pro and used the same number of iterations to get a true comparison there.

Obviously the main point of the article is to compare different python optimisations, however "rewrite it in C/C++/rust/Go" is an option that should be considered, and none of his optimisations on his M4 Pro beat the C option on my 6-year old M1 mac mini.

The rest of the numbers in the blog post use a 500k iterations for the nbody simulation. Here's my numbers on the M1 mac using the default Clang installed with xcode:

    Clang 17.0.0.   0.06s
    python 3.12.11  1.59s
    pypy 3.11.13.   0.23s 

clang -O3 -march=native nbody-gcc-6.c -o nbody.clang6

Used the python version from [2].

[1] http://benchmarksgame-team.pages.debian.net/benchmarksgame/p...

[2] https://github.com/cemrehancavdar/faster-python-bench/tree/m...

The language itself is not the issue, the implementations are wildly different in other ways

I have used Julia for my main language for years. Yes, it really does solve the two language problem. It really is as fast as C and as expressive as Python.

It then gives you a bunch of new problems. First and foremost that you now work in a niche language with fewer packages and fewer people who can maintain the code. Then you get the huge JIT latency. And deployment issues. And lack of static tooling which Rust and Python have.

For me, as a research software engineer writing performance sensitive code, those tradeoffs are worth it. For most people, it probably isn’t. But if you’re the kind of person who cares about the Python optimization ladder, you should look into Julia. It’s how I got hooked.

As a sibling comment mentions, yes it does. Just don’t expect to have code that runs as fast as C without some effort put into it. You still need to write your program in a static enough way to obtain those speed. It’s not the easiest thing in the world, since the tooling is, yes, improving but is still not there yet.

If you then want to access fully trimmed small executables then you have to start writing Julia similarly to how you write rust.

To me the fact that this is even possible blows my mind and I have tons of fun coding in it. Except when precompiling things. That is something that really needs to be addressed.

This problem has been solved already by Lisp, Scheme, Java, .NET, Eiffel, among others, with their pick and choose mix of JIT and AOT compiler toolchains and runtimes.

If you're patching hot paths with C and praying the interface layer doesn't explode, you can spend almost as much time chasing ABI boundary bugs as you save on perf. Type hints in Python are still docs for humans and maybe your LSP. Julia does address the two language problem in theory, but getting your whole stack and your deps to exist there is its own wierd pain, and people underplay how much library inertia matters once you leave numerics.

Be careful with that, numpy arrays can be slower than Python tuples for some operations. The creation is always slower and the overhead has to be worth it.

You can turn trees into numpy-style matrix operations because graphs and matrices are two sides of the same coin. I don't see the code for the binary-tree benchmark in the repo to see how it's written, but there are libraries like graphblas that use the equivalence for optimization.

Being upfront about AI-assistance or no AI-assistance doesn't mean shit. Whether AI was involved is independent of what they state and there's no real way to fully prove otherwise.

Typescript is basically a JavaScript linter.

The benefit is that JavaScript JIT compilers have a few decades of research behind them, all the way back to Smalltalk and SELF.

So in many cases you can still stay with V8 or JavaScript Core, instead of rewriting into something else, regardless of the whole rewriting into Rust that is now fashionable.

As a mostly Python programmer and partly TypeScript programmer, my subjective thought is that a bit more 'noise' with TypeScript than Python.

Just a little more to parse with my eyes and a little more to type with TypeScript.

But hey, with all these cool kids with their AI coding agents, reading and handwriting code may soon be obsolete!

It's missing the easiest of the choices: grab a coffee and come back when it has run.

They're cheap but not free, especially at the front end of the CPU where it's just a lot more instructions to churn through. What the branch predictor gets you is it turns branches, which would normally cause a pipeline bubble, to be executed like straightline code if they're predicted right. It's a bit like a tracing jit. But you will still have a bunch of extra instructions to, like, compute the branch predicate.

From when I was working on optimizing one or two things with Cython years ago, it wasn’t per-se the branch cost that hurt: it was impeding the compiler from various loop optimisations, potentially being the impediment from going all the way to auto-vectorisation.

> a garbage collected rust like language with fast compilation

I don't know what languages you might have in mind. "Rust-like" in what sense?

One thing with python is that usually I will use one of the many c based libraries to get reasonable speed and well thought out abstractions from the start. I architect around numpy, scipy, shapely, pandas/polars or whatever. So my code runs at reasonable speed from the start. But transpiling to rust then effectively means a complete redesign of the code, data structures, algorithms etc. And I have seen the AI tools really struggle to get it right, as my intent gets lost somewhere.

So what I do now (since Claude Code) is write really bare bones (and slow) pure python implementation (like I used to do for numba, pypy or cython ready code), with minimal dependencies. Then I use the REPL, notebooks and nice plotting tools to get a real understanding of the problem space and the intricacies of my algorithm/problem at hand. When done, I let Claude add tests and I ask it to transpile to equivalent Rust and boom! a flawless 1000x speed upgrade in a minutes.

The great thing is I don't need to do the mental gymnastics to vectorize code in a write only mode like I've had to do since my Matlab days. Instead I can write simple to read for loops that follow my intent much better, and result in much more legible code. So refreshing!

And with pyO3 i can still expose the Rust lib to python, and continue to use Python for glue and plotting

That has been a thing forever, many "Python" libraries, are actually bindings to C, C++ and Fortran.

The culture of calling them "Python" is one reason why JITs are so hard to gain adoption in Python, the problem isn't the dynamism (see Smalltalk, SELF, Ruby,...), rather the culture to rewrite code in C, C++ and Fortran code and still call it Python.

There's no surprise that Rust is faster to run, but I don't think there are many who would claim that Rust is faster to write.

Because for 99% of cases python is fast enough and it's fast as fuck to code. And for the 1% that aren't, you have 50 different flavors of making it faster. And the final of which is "slap pybind on a c module to do the hot path in C" which then lets you minimize the suffering of C into a single high value location. And the rest of the code still gets to be Python.

Beyond the economic arguments, there’s a lot in JS that actually makes it a lot easier: almost all of the operators can only return a subset of the types and cannot be overridden (e.g., the binary + operator in JS can only return a string or a number primitive), the existence of like string and number primitives dramatically reduce the amount of dynamic behaviour they can have, only proxy objects can exhibit the same amount of dynamism as arbitrary Python ones (and thus only they pay the performance cost)…

The more real answer is that python's primary usage is a glue language. It has to be able to interface with various C libraries, and to make the interfaces even more ergonomic, they exposed several internal details on how code is evaluated that libraries make use of (e.g. you can increment/decrement a ref counted python object's counter from C).

This pretty much makes it impossible to change many of the internal details, and to significantly optimize it.

If we remove this requirement, we get the alternative runtimes and if you check e.g. GraalPy, it has the same order of performance as JS, so your intuition is right. It's just that you have to drop supporting a good chunk of what people use Python for which is obviously a no go for most applications. (Note: GraalPy can actually also run some C libraries and in this case can cross-optimize across python and C!)

> ok I guess the harder question is. Why isn't python as fast as javascript?

Actually there is a pretty easy answer: worldwide, the amount of javascript being evaluated every day is many orders of magnitude higher than the amount of python. The amount of money available for optimizing it has thus been many orders of magnitude higher as well.

Yea while reading, I just didn't understand how you end up LLM writing the article? Clearly, the data and writeup are real. But, was it "edited" with an LLM? It looks closer to ~the entire thing being LLM written. I finished reading because the topic is interesting, but the LLM writing style is difficult to bear.. and I agree with your point that trying to fool us that it's human with `--` is just absurd

Same problems, same Apple M4 Pro, real numbers.

Isn't this a depressing thought? Regardless of AI, to think that everything we read would come in the same literary style, conveying little of the author, giving no window through which to learn about who they are -- that would be a real loss.

Why is it amusing?

How can you suppose that this is not a good reason to object, especially days after https://news.ycombinator.com/item?id=47340079 ?

I find the style so reflexively grating that it's honestly hard for me to imagine others not being bothered by it, let alone being bothered by others being bothered.

Especially since I looked at previous posts on the blog and they didn't have the same problem.

The smell makes me suspicious because I don’t know how the author used AI.

If the author wrote a detailed rough draft, had AI edit, reviewed the output thoroughly, and has the domain knowledge to know if the AI is correct, then this could be a useful piece.

I suspect most authors _don’t_ fall in that bucket.

> detractors-for-no-good-reason

It's partly just a matter of taste; we can disagree on whether that's a good reason, but I'd be surprised if there were no writing styles that you personally find offputting.

The LLM smell is also a signal of low effort, and a signal that we as readers can't rely on our usual heuristics for judging credibility. The whole thing with LLMs is that they're great at producing polished, plausible-looking outputs, but they're still prone to bullshitting and making errors that don't match the usual human patterns. (And of course they're a great tool for churning out human-initiated disinformation.) If you don't have any kind of immune response against the LLM smell, I reckon you're probably absorbing more bs than you realise.

Yeah, while posting how they are using Claude to do something really amazing.

"I totally get a kick out of the peeps who find the writeup super helpful yet are totally put off by that distinct "AI smell"—it’s like they can't even! Just imagine when everything we value is woven into a tapestry of that same "smell"—where will all the naysayers retreat to then? It’s a little frustrating, honestly, and I’m just like, come on! Let’s delve into this new era of content and embrace the chaos!"

There, FTFY :D

While I sympathize (and have said similar in the past), language design can (and in Python's case certainly does) hinder optimization quite a bit. The techniques that are purely "use a better implementation" get you not much further than PyPy. Further benefits come from cross-compilation that requires restricting access to language features (and a system that can statically be convinced that those features weren't used!), or indeed straight up using code written in a different language through an FFI.

But yes, the very terminology "interpreted language" was designed for a different era and is somewhere between misleading and incomprehensible in context. (Not unlike "pass by value".)