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Comment by scrollaway | Hacker News Reader

Can someone explain why UV is so praised when Poetry achieved a lot of that good several years earlier? Maybe I missed the train but I’ve been using poetry since its first version and all the benefits people praise UV for have long been in my builds.

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Ruff was the gateway drug for me, much better than the black/isort/etc combo.

Led me to try uv, which fixed a couple of egregious bugs in pip. Add speed and it’s a no brainer.

I don’t think poetry has these advantages, and heard about bugs early on. Is that completely fair? Probably not. But it’s obvious astral tools have funding and a competent team.

Speed and simplicity. Now I can fetch one binary on a system and in seconds fetch everything needed to run a Python tool or work on a code base.

I can do all that without having to even worry about virtual ends, or Python versions too.

after using both for the past 5 years, I'd say the main difference between peotry and uv is user experience and documentation. Poetry fought me every step of the way w.r.t. pip migration, venv, poetry updates. uv just worked in these areas, which meant I was updating packages much more frequently, which increased my experience and confidence in uv for a virtual cycle.

Poetry was in some senses before its time; people were frustrated with pip, but didn't really understand the problems they were encountering, meanwhile the ecosystem had started trying to move away from doing everything with Setuptools for everyone. There's a ton that I'd love to explain here about the history of pyproject.toml etc. but the point is that Poetry had its own idea about what it would mean to be an all-in-one tool... and so did everyone else. Meanwhile, the main packaging people had been designing standards with the expectation of making a UNIX-style tool ecosystem work.

Everyone seems to like uv's answer better, but I'm still a believer in composable toolchains, since I've already been using those forever. I actually was an early Poetry adopter for a few reasons. In particular, I would have been fine sticking with Setuptools for building projects if it had supported PEPS 517/518/621 promptly. 621 came later but Poetry's workaround was nicer than Setuptools' to me. And it was easier to use with the new pyproject.toml setup, and I really wanted to get away from the expectation of using setup.py even for pure-Python projects.

But that was really it. The main selling point point of Poetry was (and is) that they offered a lockfile and dependency resolution, but these weren't really things I personally needed. So there was nothing really to outweigh the downsides:

* The way Poetry does the actual installation is, as far as I can tell, not much different from what pip does. And there are a ton of problems with that model.

* The early days of Poetry were very inconsistent in terms of installation and upgrade procedures. There was at least once that it seemed that the only thing that would work was a complete manual uninstall and reinstall, and I had to do research to figure out what I had to remove for the uninstallation as there was nothing provided to automate that.

* In the end, Poetry didn't have PEP 621 support for about four years (https://github.com/python-poetry/roadmap/issues/3 ; the OP was already almost a year after PEP acceptance in https://discuss.python.org/t/_/5472/109); there was this whole thing about how you were supposed to use pyproject.toml to describe the basic metadata of your project for packaging purposes, but if you used Poetry then you used Masonry to build, and that meant using a whole separate metadata configuration. Setuptools was slow in getting PEP 621 support off the ground (and really, PEP 621 itself was slow! It's hard to justify expecting anyone to edit pyproject.toml manually without PEP 621!), but Poetry was far slower still. I had already long given up on it at that point.

So for me, Poetry was basically there to provide Masonry, and Masonry was still sub-par. I was still creating venvs manually, using `twine` to upload to PyPI etc. because that's just how I think. Writing something like `poetry shell` (or `uv run`) makes about as much sense to me as `git run-unit-tests` would.

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