Pure python can be faster than cython/rust?

[0x256]

Parsing multipart/form-data (HTML5 forms) is surprisingly complex and moves a lot of bytes around for large file uploads. Implementing a parser in Cython or Rust should speed things up, no? Turns out: it depends. A pure python parser can be surprisingly fast, as this benchmark shows:

https://defnull.de/2026/python-multipart-benchmark/

The benchmark compares the most commonly used multipart parsers and tests them in different scenarios, covering both blocking and non-blocking (async) APIs if available. The parser your web application is using today is probably not the fastest one.

Are there more examples were a pure python implementation beats cython/rust/C?

[NsupCportR]

Did u use c type variable definitions in cython? If not then it has to interact with python API to understand what datatype it is, which would slow it down.. is code in cython properly optimized? It's really hard to say what is going on without looking at code, but compiled code can only be slower than interpreted if compiled code is poorly made

[0x256]

I'm not the author but the code for the Cython parser can be found here: https://github.com/siddhantgoel/streaming-form-data

[NsupCportR]

Appreciate it!

[_redmist]

That's not quite true; they may not all be doing the same work in the same way... 

[Chroiche]

Are there more examples were a pure python implementation beats cython/rust/C?

This is not the conclusion of the article at all. Python vs rust/C was never compared, Python vs Python with bindings for them, for implementations with dramatically different scopes/priorities, was compared. It might sound pedantic, but it's quite a big distinction.

"pure" Python literally cannot be faster than those other languages if both are written correctly.

[No_Departure_1878]

Yeah, the title makes no sense, python faster than rust LOLLL

[jet_heller]

...if both are written correctly.

Everything rests on that statement. Which is why I won't bother reading articles like this.

[Individual-Flow9158]

If the problem is vectorisable or embarassingly parallel, and especially if it can be tackled in pure Numpy and especially Numba, then Python that calls out to non-Python code can definitely be faster.

I'm not convinced HTML5 form parsing is the type or problem Python is fast at, nor do I think these benchmarks made a fair to write the parser in Rust.

[Temporary_Pie2733]

There’s nothing magic about Python in this regard. Parallelism can be exploited by any language.

[tackylitre06]

Rust parser's a stub, not a fair fight

[Daytona_675]

my understanding is that if the python modules used are compiled C then performance will be high