2024-05-29
PyPy has been quietly working for me for several years now
A number of years ago I switched to installing various Python programs through pipx so that each of them got their own automatically managed virtual environment, rather than me having to wrestle with various issues from alternate approaches. On our Ubuntu servers, it wound up being simpler to do this using my own version of PyPy instead of Ubuntu's CPython, for various reasons. I've been operating this way for long enough that I didn't really remember how long.
Recently we got our first cloud server, and I wound up installing our cloud provider's basic CLI tool. This CLI tool has a number of official ways of installing it, but when the dust settles I discovered it was a Python package (with a bunch of additional complicated dependencies) and this package is available on PyPi. So I decided to see if 'pipx install <x>' would work, which it did. Only much later did it occur to me that this very large Python and stuff tool was running happily under PyPy, because this is the default if I just 'pipx install' something.
As it turns out, everything I have installed through pipx on our servers is currently installed using PyPy instead of CPython, and all of it works fine. I've been running all sorts of code with PyPy for years without noticing anything different. There is definitely code that will notice (I used to have some), but either I haven't encountered any of it yet or significant packages are now routinely tested under PyPy and hardened against things like deferred garbage collection of open files.
(Some current Python idioms, such as the 'with' statement,
avoid this sort of problem, because they explicitly close files and
otherwise release resources as you're done with them.)
In a way there's nothing remarkable about this. PyPy's goal is to be a replacement for CPython that simply works while generally being faster. In another way, it's nice to see that PyPy has been basically completely successful in this for me, to the extent that I can forget that my pipx-installed things are all running under PyPy and that a big cloud vendor thing just worked.