Ask HN: Is anyone using PyPy for real work?

I have been the release manager for PyPy, an alternative Python interpreter with a JIT [0] since 2015, and have done a lot of work to make it available via conda-forge [1] or by direct download [2]. This includes not only packaging PyPy, but improving on an entire C-API emulation layer so that today we can run (albeit more slowly) almost the entire scientific python data stack. We get very limited feedback about real people using PyPy in production or research, which is frustrating. Just keeping up with the yearly CPython release cycle is significant work. Efforts to improve the underlying technology needs to be guided by user experience, but we hear too little to direct our very limited energy. If you are using PyPy, please let us know, either here or via any of the methods listed in [3].

[0] https://www.pypy.org/contact.html [1] https://www.pypy.org/posts/2022/11/pypy-and-conda-forge.html [2] https://www.pypy.org/download.html [3] https://www.pypy.org/contact.html

I use PyPy quite often as a 'free' way to make some non-numpy CPU-bound Python script faster. This is also the context for when I bring up PyPy to others.

The biggest blocker for me for 'defaulting' to PyPy is a) issues when dealing with CPython extensions and how quite often it ends up being a significant effort to 'port' more complex applications to PyPy b) the muscle memory for typing 'python3' instead of 'pypy3'.

For the b) part, you should consider creating alias for that command, if it really might lead for you to not use it otherwise.

I don't use PyPy because when I'm stuck with performance issues, I go to numpy and if it really doesn't work I go to cython/numba (because it means that 99% of my python code continue to work the same, only the 1% that gets optimized is different; if I'd go PyPy, I'd have to check my whole code again). I do mostly computational fluid dynamics.

(nevertheless, PyPy is impressive :-) )

This post is a funny coincidence as I tried today to speed-up a CI pipeline running ~10k tests with pytest by switching to pypy.

I am still working on it but the main issue is psycopg support for now, as I had to install psycopg2cffi in my test environment, but it will probably prevent me from using pypy for running our test suite, because psycopg2cffi does not have the same features and versions as psycopg2. This means either we switch our prod to pypy, which won't be possible because I am very new in this team and that would be seen as a big, risky change by the others, or we keep in mind the tests do not run using the exact same runtime as production servers (which might cause bugs to go unnoticed and reach production, or failing tests that would otherwise work on a live environment).

I think if I ever started a python project right now, I'd probably try and use pypy from the start, since (at least for web development) there does not seem to be any downsides to using it.

Anyways, thank you very much for your hard work !