I'd rather `ruff` being merged with `ty` instead. `uv` for me is about package / project manager. It's not about code style. The only time `uv` should edit a code file is to update its dependencies (PEP 723).
On the other hand, both `ruff` and `ty` are about code style. They both edit the code, either to format or fix typing / lint issues. They are good candidates to be merged.
To clarify, `ruff` and `uv` aren't being merged. They remain separate tools. This is more about providing a simpler experience for users that don't want to think about their formatter as a separate tool.
The analogy would be to Cargo: `cargo fmt` just runs `rustfmt`, but you can also run `rustfmt` separately if you want.
Isn’t there `uv tool run ruff` already for this? Or `uv run ruff` if it’s a proper dependency? I’m not sure what’s the point of a special shortcut command, unless there are plans to make it flexible so it’ll be an abstraction over formatters (unifying ruff, black, etc).
Is `uv format` supposed to be an alias for `ruff check`?
Stupidly I ran `uv format` without `--check` (no harm done and I can `git diff` it) so I didn't see the changes it made but `ruff check` does still show things that can be fixed with `ruff check --fix`. If I'm guessing correctly the difference is coming down to the fact that I have (in my submodule where all changes were made) a pyproject.toml file with ruff rules (there's also a .flake8 file. Repo is being converted). Either way, I find this a bit confusing userside. Not sure what to expect.
I think one thing I would like is that by default `uv format` spits out what files were changed like `uv format --check` does (s/Would reformat/Reformatted/g). Fine for the actual changes not to be displayed but I think this could help with error reduction. Running it again I can see it knows 68 files were changed. Where is that information being stored? It's pretty hard to grep out a number like that (`grep -R \<68\>`) and there's a lot of candidates (honestly there's nothing that looks like a good candidate).
Also, there's a `--quiet` flag, but the output is already pretty quiet. As far as I can tell the only difference is that quiet suppresses the warning (does `--quiet` also suppress errors?)
uv format
warning: `uv format` is experimental and may change without warning. Pass `--preview-features format` to disable this warning.
36 files reformatted, 31 files left unchanged
uv format --quiet
36 files reformatted, 31 files left unchanged
I like the result for `--quiet` but I have a strong preference that `uv format` match the verbosity of `uv format --check`. I can always throw information away but not recover. I have a strong bias that it is better to fail by displaying too much information than fail by displaying too little. The latter failure mode is more harmful as the former is much more easily addressed by existing tools. If you're taking votes, that's mine.
Anyways, looking forward to seeing how this matures. Loved everything so far!
> To clarify, `ruff` and `uv` aren't being merged.
ruff at least seems to be compiled into uv, as the format worked here without a local ruff. This is significant more than just an interface. Whether they are managed and developed as separate tools doesn't matter.
> This is more about providing a simpler experience for users that don't want to think about their formatter as a separate tool.
Then build a separate interface, some script/binary acting as a unified interface, maybe with its separate distribution of all tools. Pushing it into uv is just adding a burden to those who don't want this.
uv and ruff are poor names anyway, this could be used to at least introduce a good name for this everything-python-tool they seem to aim for.
Including a formatter in a package manager doesn't make sense to me. Seems like obvious feature creep.
My understanding was that uv is for installing dependencies (e.g. like pip) with the added benefit of also installing/managing python interpreters (which can be reasonably thought of as a dependency). This makes sense. Adding more stuff doesn't make sense.
And I would think the next logical step here is to have a `uv lint` option here that runs ˋty` under the hood ?
I would love to see a world where there is a single or a set of standard commands that would prepare your python project (format, lint, test, publish). Maybe that’s the vision here?
this is very much in line with the unix philosophy - it delegates formatting to ruff and simply provides a unified front end that calls out to the right specialized tool. think of it as a makefile.
There is wisdom in knowing when -- and how -- to break standards. Don't know if this is the case, but I think it is. If introducing fmt powers to UV meant it had to consider tradeoffs elsewhere where it might hurt its quality somehow then maybe, but in this case UV is more like an umbrella, unifying the interface for pip, venv, builds... And now fmt. All keeping each separate domain isolated without details leaking to one another.
The spirit of the unix philosophy is not implementing MxN use cases separately. Running the same program as a separate binary or as a subcommand has nothing to do with it
The reality is, ecosystems evolve. First, we had mypy. Then more type checkers came out: pyre, pyright, etc. Then basedpyright. The era of rust arrived and now we have `ty` and `pyrefly` being worked on heavily.
On the linter side we saw flake8, black, and then ruff.
Decoupling makes adapting to evolution much easier. As long as both continue to offer LSP integrations it allows engineers to pick and chose what's best.
The whole premise of uv that you don't need to know that you can install specific python version using eg pyenv (`uv python install` or `uv run` may do it implicitly), you don't need to know about `python -m venv`/virtualenv (`uv venv`), or how to create lock files pip-tools / pipenv / poetry / etc(`uv lock`), or pipx (`uv tool install`) or `pip install`/ `pipenv install`/`poetry add` / many others (`uv add`), or how to build artifacts setuptools / hatchling / poetry way / etc (`uv build`). Other commands such as `uv sync` didn't break new ground too.
`uv format` is similar (you don't need to know about `ruff format` / black / yapf ).
I enjoy using uv a lot but am getting afraid that it is getting bloated for no reason. For ex., the number of niche flags that a lot of subcommands support is very high + some of them seemingly achieve the same result(uv run --no-project and uv run --active). I'd rather them working on improving existing tools and documentation than adding new (redundant) functionality
It's really difficult to do Python projects in a sound, reproducible, reasonably portable way. uv sync is in general able to build you only a package set that it can promise to build again.
But it can't in general build torch-tensorrt or flash-attn because it has no way of knowing if Mercury was in retrograde when you ran pip. They are trying to thread a delicate an economically pivotal needle: the Python community prizes privatizing the profits and socializing the costs of "works on my box".
The cost of making the software deployable, secure, repeatable, reliable didn't go away! It just became someone else's problem at a later time in a different place with far fewer degrees of freedom.
Doing this in a way that satisfies serious operations people without alienating the "works on my box...sometimes" crowd is The Lord's Work.
> But it can't in general build torch-tensorrt or flash-attn because it has no way of knowing if Mercury was in retrograde when you ran pip.
This is a self-inflicted wound, since flash attention insist on building a native C++ extension which is completely unnecessary in this case.
What you can do is the following:
1) Compile your CUDA kernels offline.
2) Include those compiled kernels in a package you push to pypi.
3) Call into the kernels with pure Python, without going through a C++ extension.
I do this for the CUDA kernels I maintain and it works great.
Flash attention currently publishes 48 (!) different packages[1], for different combinations of pytorch and C++ ABI. With this approach it would have to only publish one, and it would work for every combination of Python and pytorch.
I don’t understand why adding a subcommand to uv is being considered bloat.
uv is already a complex tool, but it has excellent documentation. Adding a straightforward, self-explanatory subcommand like this doesn’t seem out of place.
Developing a good and configurable formatter is a project almost as complex as uv's main focus, managing packages. As such it will divert time and attention from its main purpose and the outcome is questionable, considering how many bad formatters are out there. For example the "opinionated" black is terrible and has no awareness of semantics.
This is obviously a great move. I don't know why so many commenters here are against making things better. "Can't you just do <this slightly worse thing> already?". Well yes. But it's slightly worse.
I don't think being one word longer ("uvx ruff format" vs "uv format") counts as being is worse.
I think it is much worse to create a special case that obscures the actual formatter being run and how it is being run (is ruff now preinstalled, or is it downloaded and cached in the same way as other tools?)
I anticipate this will make it much easier for me to get my little team of actuaries formatting their code.
The impact of uv on our onboarding and utilisation of python has already been huge, and any way I can easily improve their code hygiene is a good one. Yes, I could get them to use ruff standalone, or set up pre-commit hooks etc for them, but the simple mental model that comes from `uv <do something>` is really beneficial.
Will have a play around with this and see how it goes. Would love to be able to hook into other formatters too, but not sure if that's easy or even possible already. For example, I would love it if `uv format` also formatted our SQL/dbt models.
At that point I think you start wanting Makefiles, or preferably IMO justfiles. Then you can run `just format` and have it format your combined Python/SQL/Bash/TypeScript project.
This feels like feature creep. I've been using uv more and more over the past year (mostly because I work with projects that use it) and although I like it and recognize the advantages, it is still not my first choice, and this kind of thing isn't going to help that...
What's wrong with this approach specifically? Go does it this way. Rust does it this way. Elixir does it this way. It reduces the toil in setting up and using projects in those ecosystems substantially. It unifies community effort behind a common set of tools and provides beginners and experts alike with a shared entrypoint to projects.
What's wrong with the approach is that it goes against basic principles of the Python ecosystem. Python has always followed the policy of standardising mechanisms and allowing implementations to develop and peacefully coexist. The Python way fosters diversity of implementations. Note that uv itself would not be a reasonable project if not for Python's approach to diverse tooling.
You cite good examples where other languages have chosen to standardise tooling. We can discuss the pros and cons of that choice. But it is a choice, and Python already made a different choice.
One thing I wonder about is what happens in pyproject? Do you use tool.ruff/tool.ruff.format or tool.uv.format or what? Are people who only know "uv format" supposed to understand that part? Does ruff start honoring tool.uv.format? Which have priority over which in search. Does it behave differently when you run uv format vs ruff format? etc
It wouldn't surprise me if the ruff featurset eventually gets integrated into uv and ty. The linting seems to better suited to ty which would be able to provide more intelligent linting since it understands the codebase better. And the formatting seems better suited to uv since that's all about managing your project.
Mixing a package manager, (which is needed for prod package installs) with dev-only tooling is analogous to an "attractive nuisance" (not that I'm saying anyone is a child mind). I know Go and Rust do it, but thinking from first principles, it sounds like a bad idea.
It really does sound like a bad idea, and now that I've used cargo a lot, I want a lot more of those bad ideas in my life.
Seriously, if uv becomes to Python what cargo is to Rust, the developer experience for Python is going to be vastly better than before. I've been writing Python professionally for more than 25 years, and getting paid to work around it's crummier parts, and I'm thrilled to be able to throw away all that knowledge and just use uv.
Having worked with many python repos, that didn’t know any better to follow conventions or that the tooling ecosystem has meaningful options, I am ecstatic to see formatting and linting be a first class feature of the modern python experience.
I know this is a hot take, but so much headache saved down the road to “force” this stuff up front.
Does it have to be "force" stuff up front? Surely there are less violent ways to ease new developers into conventions and tooling than the dictatorial approach.
I switched to ruff for the great linting. When they introduced a formatter, I gave it a try and:
- got similar results
- but runs faster
- I could delete one dev dependency
Given black's motto (any color as long as it's black), now I pick ruff and go with whatever formatting it produces.
This is starting to sound like uv is a trojan horse that was introduced as a package manager and is now seeking to replace the diverse python ecosystem with a totalizing approach that is anathema to the the python way (standardize protocols, accommodate diverse implementations).
Cargo is a hybrid of package manager and build system. So it has frontend fommands wrapping a formatter and loads of other stuff, like code linters, as part of the build system. I've used cargo to build projects even when they have no dependencies and I don't plan to bundle them up and publish them as crates.
Ok, but we will go a step further and also integrate the remaining of ruff features? Because we have `go vet`. Does it even make sense to have the linter integrated too?
I am not sure I like this either. I think linter and formatter are more like developer dependencies, especially because both formatter and linters are generally things that you want to lock to a specific version to avoid e.g. CI failures or mass changes when a version is updated. But I can understand that having a formatter always available may be nice.
internally, they are working on ty and some of its logic is going to have to call out to uv. I imagine that things like this is being built to experiment with some of the connections and interfaces between tools.
The astral team is pretty responsive to questions and feedback. If this type of change concerns you (as an actual user of the tool) please reach out to them. My big thing right now is integrations with workspaces. And if special case commands is the answer,,, well not ideal but I’ll take it.
The native integration offers persistent configuration, caching, and project-aware behavior that uvx (which just creates an ephemeral venv) doesn't provide.
I would imagine that a person who is seriously concerned about any of that would just install a standalone version of ruff. Given the existence of uvx, this addition seems like feature creep to me.
Of course we already have it automated in pre-commit checks, I'm just mildly annoyed that it's two different commands in the first place (though I'm sure there is some good historical reason). The distinction/ordering between them isn't really clear as a user, I just want "find and fix everything you can, error if you cant autofix" every time.
Just so you know, when people say "I hate this paper cut", they aren't really asking how they can put in extra work to get around it. Obviously hey can add some alias to ~/.bashrc... on every computer he uses. The complaint is that he has to do that in the first place. It's still annoying.
uv is trying to deliver the same experience as cargo does for rust. Just install a single CLI and it's the only tool you have to worry about when working on your Python project.
There's nothing wrong with `ruff format`, but it's nice to have `uv` as a universal entrypoint.
> Try out uv format in your next project and see how it fits into your development workflow. The experimental nature means your feedback could help shape how this feature evolves.
So maybe nobody has been waiting for this and the feedback will be: we don’t need this.
Also it uses ruff under the hood. If it’s integrated with uv, an advantage is one less tool to juggle.
I've been playing around with go quite a bit lately, and now think that being bundled is actually a really serious advantage.
Being able to just to "go fmt", without needing any additional tools, is a really great thing about the language.
The only danger that I can see (and it is a big one) is that Python doesn't have the same kind of consistency that go does. It might end up failing just because so many people use Python in such different ways.
Is it just me, or do other people also have the impression that a lot of sock puppets are advertising for the Astral company on the internet?
That said, I may not have installed super complex packages, but for years now I have never ever experienced one situation (on Windows, ok) where pip did not just work. For me, pip is the way.
I also have the Python folder be a Git repo, and every `pip install` is a commit, and every project is a branch. Why so difficult?
Meanwhile, they provide identical functionality. (`Under the hood, it calls Ruff’s formatter to automatically style your code according to consistent standards.`)
Good questions. I don't think we'd ever deprecate Ruff because `uv format` exists, and adding `uv format` won't have any impact on Ruff's release cycles or development. The analogy would be to Cargo: `cargo fmt` just runs `rustfmt`, but you can also run `rustfmt` separately if you want.
A lot of users just want a simpler experience. They want to install uv, run `uv run` to run their project, `uv format` to format it, etc. The idea here is to experiment with providing that functionality and see if folks find it useful. Maybe they won't want it! It's experimental :)
i expect to hear "hey replygirl, can we upgrade from ruff to uv format?" from 5 of my coworkers in the next month, and "what's the difference between ruff and uv format?" from another 10. per interaction i expect 2 minutes of reading and explaining, plus an average 5 minutes listening to the other party wax philosophical. so the convenience costs my job $400
I'm just going to ask this: if your coworkers ask "can we upgrade from ruff to uv format," and it takes you that much time to explain it, have you just considered going "sure thing," spending two hours on Twitter, and pushing a commit and getting paid for it?
Package managers providing a shortcut to call a standardized formatter is a very popular feature in many languages, also not hard to understand the appeal:
Cool. I want a do it all python tool. Ruff is great. Having it out of the box with uv is great. Less crap to mess with. I haven’t tried ty yet, but looking forward to not having to mess with pyright.
Not all devs have very deep knowledge of the ecosystem, some will get to use a tool only if it's part of the default set of tools they're provided.
Plus, it saves on memorizing a name if you only use python once in a long while.
There just isn't much of a reason not to.
I landed in python last year, the pre uv time for me. The language itself is fine, but the project organization sucked. What kind of folder structure to choose? Do I use pip, env, pipenv, poetry? How to format, and with which settings? I've read tens of blog post, all giving different choices, all equally reasonable, all having some downsides.
The great thing about uv is not that their choices are best, it's that the choices have been made, the gordian knots cut. There is a good enough standard to build upon. Future python projects will look a lot more like each other, and less time will be wasted on organizational minutiae.
As someone who has worked on package managers quite a bit in the past, and for that examined prior art across package managers, that's because Cargo is doing things very well on almost all fronts. Partially because of their RFC process and partially because they have the luxury of being a "newer" package manager that doesn't have to live with ecosystem baggage going many decades back.
There are/were definitely some weaker spots with Cargo (e.g. private registry support was meh for some time), but if one were tasked to build a package manager and were only allowed to pick a single one to take inspration from, Cargo is definitely the way to go.
Anyone from uv reading this?
please scrap this thing, there is a separate formatter ruff that anyone ll use if they want a formatter. please do not complicate stuff. ruff ll come with its own configuration. this will have its own config at some point. potential rule clashes, ignore plugins. please do not go in this direction
A clean alternative: automatically adding ruff as a tool when creating a new pyproject.toml file, with a command line flag to opt out for the minority who know they don't intend to use ruff. For the majority of users, simplicity is worth an accidental download.
I recognize that uv is very popular but it still feels faddish.
I don't want my package manager to format anything.
I don't want my package manager to lint anything.
I don't want my package manager to `run` anything.
I don't want my package manager to even manage environments (yes yes this one is a bit extreme).
I want to have single purpose tools that work together well.
This way I can have a flexible, composable toolchain that can both adapt to me and my specific project.
For example, I like conda, pip, ruff, mypy, flake8. Someone else might like venv, pip, black, pyright, flake8.
This is the heart of the Unix Philosophy and I feel like it's a philosophy each software community has to reject, suffer due to that rejection, and re-adopt on a regular basis. I'd rather we skip the suffering bit.
It's a minor issues in teams where people use inconsistent formatting. This causes needless complications when merging code and additional work related to resolving conflicts that shouldn't exist to begin with.
Some languages (Go, Rust) have essentially solved this issue to the point where blindly running the formatters these languages have solves the problem and is uncontroversial.
Sadly, the language of choice for me (Kotlin) has a big unaddressed problem here where what the IDE does for formatting and what independent formatting tools do are two things that are hard to align for mostly the historical reasons that what the IDE does is fragmented over different bits of code that don't listen to the same configuration. There is a lot of variation in preferences for indentation, where to put new lines, line length, what order to put imports in, which imports to use wildcards for (if any at all), etc. Particularly imports are a problem because the bit of code that organizes imports is separate from the bit of code that formats code in the IDE.
The common solution of using IDE plugins to work around this is a bit of a kludge. The proper solution would be a more sane way to just make the IDE externally configurable so that build tools can make the IDE do exactly the same as what they do without requiring users to manually configure their IDEs just right by installing plugins or fiddling with configuration. This stuff should not be user controllable if there is a build file that defines the proper formatting.
Coding agents actually add to this problem. Because getting those to stick to formatting conventions is tricky. Unless you have tools that just fix that properly.
So good change in uv and probably something I'd be using on my next python project (I do those once in a while).
I hope for uv's sake, that the formatting is always optional and that it is not "opinionated" (read: half asses and no way to configure it), but configurable. And if we get into that, well, it's a whole different tool, that they are trying to put into uv. Seems like a bad idea.
I'd rather `ruff` being merged with `ty` instead. `uv` for me is about package / project manager. It's not about code style. The only time `uv` should edit a code file is to update its dependencies (PEP 723).
On the other hand, both `ruff` and `ty` are about code style. They both edit the code, either to format or fix typing / lint issues. They are good candidates to be merged.
To clarify, `ruff` and `uv` aren't being merged. They remain separate tools. This is more about providing a simpler experience for users that don't want to think about their formatter as a separate tool.
The analogy would be to Cargo: `cargo fmt` just runs `rustfmt`, but you can also run `rustfmt` separately if you want.
Thank you for writing software for all of us Python day-jobbers who wish we were writing Rust instead.
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Isn’t there `uv tool run ruff` already for this? Or `uv run ruff` if it’s a proper dependency? I’m not sure what’s the point of a special shortcut command, unless there are plans to make it flexible so it’ll be an abstraction over formatters (unifying ruff, black, etc).
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Is `uv format` supposed to be an alias for `ruff check`?
Stupidly I ran `uv format` without `--check` (no harm done and I can `git diff` it) so I didn't see the changes it made but `ruff check` does still show things that can be fixed with `ruff check --fix`. If I'm guessing correctly the difference is coming down to the fact that I have (in my submodule where all changes were made) a pyproject.toml file with ruff rules (there's also a .flake8 file. Repo is being converted). Either way, I find this a bit confusing userside. Not sure what to expect.
I think one thing I would like is that by default `uv format` spits out what files were changed like `uv format --check` does (s/Would reformat/Reformatted/g). Fine for the actual changes not to be displayed but I think this could help with error reduction. Running it again I can see it knows 68 files were changed. Where is that information being stored? It's pretty hard to grep out a number like that (`grep -R \<68\>`) and there's a lot of candidates (honestly there's nothing that looks like a good candidate).
Also, there's a `--quiet` flag, but the output is already pretty quiet. As far as I can tell the only difference is that quiet suppresses the warning (does `--quiet` also suppress errors?)
I like the result for `--quiet` but I have a strong preference that `uv format` match the verbosity of `uv format --check`. I can always throw information away but not recover. I have a strong bias that it is better to fail by displaying too much information than fail by displaying too little. The latter failure mode is more harmful as the former is much more easily addressed by existing tools. If you're taking votes, that's mine.
Anyways, looking forward to seeing how this matures. Loved everything so far!
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> To clarify, `ruff` and `uv` aren't being merged.
ruff at least seems to be compiled into uv, as the format worked here without a local ruff. This is significant more than just an interface. Whether they are managed and developed as separate tools doesn't matter.
> This is more about providing a simpler experience for users that don't want to think about their formatter as a separate tool.
Then build a separate interface, some script/binary acting as a unified interface, maybe with its separate distribution of all tools. Pushing it into uv is just adding a burden to those who don't want this.
uv and ruff are poor names anyway, this could be used to at least introduce a good name for this everything-python-tool they seem to aim for.
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Does it have the capability to use a different formatter than ruff?
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This is cool. Is there a way to call ruff’s linter? Like `uv lint`, which would call `ruff check`.
To your analogy, it’d be like `cargo clippy`
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They are mimicking Rust's cargo, which has `cargo fmt`
> They are mimicking Rust's cargo
Cargo cargo cult?
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Also `go fmt` and `dart format`.
Doesn't cargo just have a subcommand plugin system? Or is fmt actually hard-coded into the cargo code?
I prefer the plugin system. I don't like god programs like what the npm monstrosity became.
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I think the goal is to make uv a complete package manager for Python while still giving you the option to use the parts separately.
uv is like cargo for python.
If you only need a fast type checker you can just use ty, if you just need a fast formatter and linter you can just use ruff.
Combining ruff and ty doesn't make sense if you think about like this.
Including a formatter in a package manager doesn't make sense to me. Seems like obvious feature creep.
My understanding was that uv is for installing dependencies (e.g. like pip) with the added benefit of also installing/managing python interpreters (which can be reasonably thought of as a dependency). This makes sense. Adding more stuff doesn't make sense.
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i think it's good to let them experiment! cargo (and go?) offers this already, so why not.
But what if `ty` was also eventually merged into `uv` as well? 8-)
That's probably the vision, given all from astral.sh, but `ty` isn't ready yet.
And I would think the next logical step here is to have a `uv lint` option here that runs ˋty` under the hood ?
I would love to see a world where there is a single or a set of standard commands that would prepare your python project (format, lint, test, publish). Maybe that’s the vision here?
This is the direction I expected things to go, and not something I'm especially fond of. I'll stick with UNIX-philosophy tools, thanks.
this is very much in line with the unix philosophy - it delegates formatting to ruff and simply provides a unified front end that calls out to the right specialized tool. think of it as a makefile.
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There is wisdom in knowing when -- and how -- to break standards. Don't know if this is the case, but I think it is. If introducing fmt powers to UV meant it had to consider tradeoffs elsewhere where it might hurt its quality somehow then maybe, but in this case UV is more like an umbrella, unifying the interface for pip, venv, builds... And now fmt. All keeping each separate domain isolated without details leaking to one another.
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The spirit of the unix philosophy is not implementing MxN use cases separately. Running the same program as a separate binary or as a subcommand has nothing to do with it
I mean, Go was designed by one of the authors of UNIX, and that has very much batteries-included tooling.
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Oh please no...
The reality is, ecosystems evolve. First, we had mypy. Then more type checkers came out: pyre, pyright, etc. Then basedpyright. The era of rust arrived and now we have `ty` and `pyrefly` being worked on heavily.
On the linter side we saw flake8, black, and then ruff.
Decoupling makes adapting to evolution much easier. As long as both continue to offer LSP integrations it allows engineers to pick and chose what's best.
The whole premise of uv that you don't need to know that you can install specific python version using eg pyenv (`uv python install` or `uv run` may do it implicitly), you don't need to know about `python -m venv`/virtualenv (`uv venv`), or how to create lock files pip-tools / pipenv / poetry / etc(`uv lock`), or pipx (`uv tool install`) or `pip install`/ `pipenv install`/`poetry add` / many others (`uv add`), or how to build artifacts setuptools / hatchling / poetry way / etc (`uv build`). Other commands such as `uv sync` didn't break new ground too.
`uv format` is similar (you don't need to know about `ruff format` / black / yapf ).
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I enjoy using uv a lot but am getting afraid that it is getting bloated for no reason. For ex., the number of niche flags that a lot of subcommands support is very high + some of them seemingly achieve the same result(uv run --no-project and uv run --active). I'd rather them working on improving existing tools and documentation than adding new (redundant) functionality
It's really difficult to do Python projects in a sound, reproducible, reasonably portable way. uv sync is in general able to build you only a package set that it can promise to build again.
But it can't in general build torch-tensorrt or flash-attn because it has no way of knowing if Mercury was in retrograde when you ran pip. They are trying to thread a delicate an economically pivotal needle: the Python community prizes privatizing the profits and socializing the costs of "works on my box".
The cost of making the software deployable, secure, repeatable, reliable didn't go away! It just became someone else's problem at a later time in a different place with far fewer degrees of freedom.
Doing this in a way that satisfies serious operations people without alienating the "works on my box...sometimes" crowd is The Lord's Work.
> But it can't in general build torch-tensorrt or flash-attn because it has no way of knowing if Mercury was in retrograde when you ran pip.
This is a self-inflicted wound, since flash attention insist on building a native C++ extension which is completely unnecessary in this case.
What you can do is the following:
1) Compile your CUDA kernels offline. 2) Include those compiled kernels in a package you push to pypi. 3) Call into the kernels with pure Python, without going through a C++ extension.
I do this for the CUDA kernels I maintain and it works great.
Flash attention currently publishes 48 (!) different packages[1], for different combinations of pytorch and C++ ABI. With this approach it would have to only publish one, and it would work for every combination of Python and pytorch.
[1] - https://github.com/Dao-AILab/flash-attention/releases/tag/v2...
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I don’t understand why adding a subcommand to uv is being considered bloat.
uv is already a complex tool, but it has excellent documentation. Adding a straightforward, self-explanatory subcommand like this doesn’t seem out of place.
Developing a good and configurable formatter is a project almost as complex as uv's main focus, managing packages. As such it will divert time and attention from its main purpose and the outcome is questionable, considering how many bad formatters are out there. For example the "opinionated" black is terrible and has no awareness of semantics.
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> I don’t understand why adding a subcommand to uv is being considered bloat.
It's simple:
- Everything I use and I see: good
- Everything I don't use and I see: bloat
- Everything I use and I don't see: good
- Everything I think I don't use and I don't see: Java
When talking about uv, this comes across similar to saying that "the 'make' command has too many targets".
Are they baked into the main executable or are they separate binaries (a la apt, cargo, etc)?
It's a separate binary -- we install Ruff if you invoke `uv format`. So if you don't invoke `uv format`, there's no impact on the binary size, etc.
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This is obviously a great move. I don't know why so many commenters here are against making things better. "Can't you just do <this slightly worse thing> already?". Well yes. But it's slightly worse.
I don't think being one word longer ("uvx ruff format" vs "uv format") counts as being is worse.
I think it is much worse to create a special case that obscures the actual formatter being run and how it is being run (is ruff now preinstalled, or is it downloaded and cached in the same way as other tools?)
Let me rewrite your comment a little bit to make clearer what you’re saying.
> I don’t think additional complexity counts as being worse.
Yes, it does.
But you have to know about ruff. I didn't, but I did know about uv.
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Strong agree, they can even make the formatter configurable in pyproject if you want to use something else.
I think the biggest thing is that it doesn't seem to support other formatters. If my project uses black I don't get to have uv format work for me.
right, but you definitely shouldn’t be using any other formatter than ruff and this helps with that
fwiw `ruff format` includes nearly all the black rules by default / supports a superset of black's options https://astral.sh/blog/the-ruff-formatter
Ruff pretty much follows the same rules as black, and can be made identical with some options tweaking.
So when I moved several projects from black to ruff, there were no changes made to the code.
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I anticipate this will make it much easier for me to get my little team of actuaries formatting their code.
The impact of uv on our onboarding and utilisation of python has already been huge, and any way I can easily improve their code hygiene is a good one. Yes, I could get them to use ruff standalone, or set up pre-commit hooks etc for them, but the simple mental model that comes from `uv <do something>` is really beneficial.
Will have a play around with this and see how it goes. Would love to be able to hook into other formatters too, but not sure if that's easy or even possible already. For example, I would love it if `uv format` also formatted our SQL/dbt models.
At that point I think you start wanting Makefiles, or preferably IMO justfiles. Then you can run `just format` and have it format your combined Python/SQL/Bash/TypeScript project.
This feels like feature creep. I've been using uv more and more over the past year (mostly because I work with projects that use it) and although I like it and recognize the advantages, it is still not my first choice, and this kind of thing isn't going to help that...
What's wrong with this approach specifically? Go does it this way. Rust does it this way. Elixir does it this way. It reduces the toil in setting up and using projects in those ecosystems substantially. It unifies community effort behind a common set of tools and provides beginners and experts alike with a shared entrypoint to projects.
What's wrong with the approach is that it goes against basic principles of the Python ecosystem. Python has always followed the policy of standardising mechanisms and allowing implementations to develop and peacefully coexist. The Python way fosters diversity of implementations. Note that uv itself would not be a reasonable project if not for Python's approach to diverse tooling.
You cite good examples where other languages have chosen to standardise tooling. We can discuss the pros and cons of that choice. But it is a choice, and Python already made a different choice.
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One thing I wonder about is what happens in pyproject? Do you use tool.ruff/tool.ruff.format or tool.uv.format or what? Are people who only know "uv format" supposed to understand that part? Does ruff start honoring tool.uv.format? Which have priority over which in search. Does it behave differently when you run uv format vs ruff format? etc
What is your first choice?
Pip, because it introduces no third-party software. This is critical in regulated industries.
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It wouldn't surprise me if the ruff featurset eventually gets integrated into uv and ty. The linting seems to better suited to ty which would be able to provide more intelligent linting since it understands the codebase better. And the formatting seems better suited to uv since that's all about managing your project.
ty is already in the same repo as ruff, so integrating seems likely
Mixing a package manager, (which is needed for prod package installs) with dev-only tooling is analogous to an "attractive nuisance" (not that I'm saying anyone is a child mind). I know Go and Rust do it, but thinking from first principles, it sounds like a bad idea.
It really does sound like a bad idea, and now that I've used cargo a lot, I want a lot more of those bad ideas in my life.
Seriously, if uv becomes to Python what cargo is to Rust, the developer experience for Python is going to be vastly better than before. I've been writing Python professionally for more than 25 years, and getting paid to work around it's crummier parts, and I'm thrilled to be able to throw away all that knowledge and just use uv.
I see zero need for this given that excellent time-testing code formatting tooling options are already available.
This smacks of feature-creep and I won't be incorporating it into any pipelines for the foreseeable future.
`uv format` is just a front-end for `ruff format`. It isn't introducing a new formatter to the ecosystem or anything like that.
You realize this is just a shortcut for one of those "time-tested" options, right? ruff format is already widely used.
But why bundle? It makes zero design sense to me.
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When is UVA going to start handling email?
Having worked with many python repos, that didn’t know any better to follow conventions or that the tooling ecosystem has meaningful options, I am ecstatic to see formatting and linting be a first class feature of the modern python experience.
I know this is a hot take, but so much headache saved down the road to “force” this stuff up front.
Does it have to be "force" stuff up front? Surely there are less violent ways to ease new developers into conventions and tooling than the dictatorial approach.
This approach is “violent”?
Foot massage and blowjob over coffee?
Do you even read you write? Work is about efficiency, not catering to every special snowflake.
Love this! I would name it `uv fmt` and add `uv vet` to the roadmap too
I use black and I like it. Where does ruff differ in terms of formatting?
It’s mostly similar, just a bit more consistent: https://docs.astral.sh/ruff/formatter/black/
and speed, it's way way faster
I switched to ruff for the great linting. When they introduced a formatter, I gave it a try and: - got similar results - but runs faster - I could delete one dev dependency
Given black's motto (any color as long as it's black), now I pick ruff and go with whatever formatting it produces.
The new `uv format` is just a shortcut for `uv run --with ruff ruff`.
Why does a package manager need a formatter at all?
Is cargo just a package manager? Go?
Careful, we're going to end up with some integrated development environment, that has all these things working nicely together!
This is starting to sound like uv is a trojan horse that was introduced as a package manager and is now seeking to replace the diverse python ecosystem with a totalizing approach that is anathema to the the python way (standardize protocols, accommodate diverse implementations).
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Cargo is a hybrid of package manager and build system. So it has frontend fommands wrapping a formatter and loads of other stuff, like code linters, as part of the build system. I've used cargo to build projects even when they have no dependencies and I don't plan to bundle them up and publish them as crates.
I don't know much about go.
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Am I just a package manager?
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Ok, but we will go a step further and also integrate the remaining of ruff features? Because we have `go vet`. Does it even make sense to have the linter integrated too?
I am not sure I like this either. I think linter and formatter are more like developer dependencies, especially because both formatter and linters are generally things that you want to lock to a specific version to avoid e.g. CI failures or mass changes when a version is updated. But I can understand that having a formatter always available may be nice.
internally, they are working on ty and some of its logic is going to have to call out to uv. I imagine that things like this is being built to experiment with some of the connections and interfaces between tools.
The astral team is pretty responsive to questions and feedback. If this type of change concerns you (as an actual user of the tool) please reach out to them. My big thing right now is integrations with workspaces. And if special case commands is the answer,,, well not ideal but I’ll take it.
Why would a type checker need to call a package manager?
Can't you just do this? Why bundle?
The native integration offers persistent configuration, caching, and project-aware behavior that uvx (which just creates an ephemeral venv) doesn't provide.
I would imagine that a person who is seriously concerned about any of that would just install a standalone version of ruff. Given the existence of uvx, this addition seems like feature creep to me.
It's not bundled. `uv format` will use the `ruff` binary and more or less run `uvx ruff format` behind the scene.
It's this "more or less" that is a problem. More complication, less reliability.
Because that's a way less obvious command.
that’s a bit slow typically
so install ruff?
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We can argue if it's a feature feature creep and if it's the right choice of formatter.
But let's appreciate that this will increase the use of formatters astronomically (or part thereof), which is an excellent thing.
As long as it does `ruff check --fix; ruff format` internally and not just one or the other, then I'm happy. Tired of running 2 commands every time.
Also needs to make sorting imports a default.
and stop removing extra leading whitespace before inline comments (#7684)
FWIW, you can pretty easily script this sort of thing. In Bash it can even be a function added to your ~/.bashrc .
Of course we already have it automated in pre-commit checks, I'm just mildly annoyed that it's two different commands in the first place (though I'm sure there is some good historical reason). The distinction/ordering between them isn't really clear as a user, I just want "find and fix everything you can, error if you cant autofix" every time.
Just so you know, when people say "I hate this paper cut", they aren't really asking how they can put in extra work to get around it. Obviously hey can add some alias to ~/.bashrc... on every computer he uses. The complaint is that he has to do that in the first place. It's still annoying.
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> an experimental new command that Python developers have been waiting for: uv format
Have developers really been waiting for this? What's wrong with ruff format?
I've been waiting.
uv is trying to deliver the same experience as cargo does for rust. Just install a single CLI and it's the only tool you have to worry about when working on your Python project.
There's nothing wrong with `ruff format`, but it's nice to have `uv` as a universal entrypoint.
> Try out uv format in your next project and see how it fits into your development workflow. The experimental nature means your feedback could help shape how this feature evolves.
So maybe nobody has been waiting for this and the feedback will be: we don’t need this.
Also it uses ruff under the hood. If it’s integrated with uv, an advantage is one less tool to juggle.
I've been playing around with go quite a bit lately, and now think that being bundled is actually a really serious advantage.
Being able to just to "go fmt", without needing any additional tools, is a really great thing about the language.
The only danger that I can see (and it is a big one) is that Python doesn't have the same kind of consistency that go does. It might end up failing just because so many people use Python in such different ways.
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Well, the same functionality used to be bundled into rye before the switch to uv. I appreciate having one less dependency to declare again.
Oh neat. I wonder if they are integrating everything into uv then.
Well that title was a lot more interesting without the parentheses that HN automatically removed.
Is it just me, or do other people also have the impression that a lot of sock puppets are advertising for the Astral company on the internet?
That said, I may not have installed super complex packages, but for years now I have never ever experienced one situation (on Windows, ok) where pip did not just work. For me, pip is the way.
I also have the Python folder be a Git repo, and every `pip install` is a commit, and every project is a branch. Why so difficult?
A Foolish Consistency is the Hobgoblin of Little Minds
https://peps.python.org/pep-0008/#a-foolish-consistency-is-t...
I wonder how a code formatting tool is going to implement that.
The HN commenters in a nutshell:
ruff: Aww, you're sweet!
uv format: Hello, human resources?
Meanwhile, they provide identical functionality. (`Under the hood, it calls Ruff’s formatter to automatically style your code according to consistent standards.`)
But why do it? Keep each tool focused on its specific goal. Will there eventually be a call to deprecate ruff because it already exists in uv?
Both tools are still evolving enough that I would not want their individual release cycles to impact each other.
Good questions. I don't think we'd ever deprecate Ruff because `uv format` exists, and adding `uv format` won't have any impact on Ruff's release cycles or development. The analogy would be to Cargo: `cargo fmt` just runs `rustfmt`, but you can also run `rustfmt` separately if you want.
A lot of users just want a simpler experience. They want to install uv, run `uv run` to run their project, `uv format` to format it, etc. The idea here is to experiment with providing that functionality and see if folks find it useful. Maybe they won't want it! It's experimental :)
Yeah the reaction is weird. It's 100% optional. People just love to complain.
i expect to hear "hey replygirl, can we upgrade from ruff to uv format?" from 5 of my coworkers in the next month, and "what's the difference between ruff and uv format?" from another 10. per interaction i expect 2 minutes of reading and explaining, plus an average 5 minutes listening to the other party wax philosophical. so the convenience costs my job $400
I'm just going to ask this: if your coworkers ask "can we upgrade from ruff to uv format," and it takes you that much time to explain it, have you just considered going "sure thing," spending two hours on Twitter, and pushing a commit and getting paid for it?
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Memes aside, the conceptual grouping of tools does matter.
Cause one is a formatter and the other is a package manager. That shouldn’t be hard to understand.
Package managers providing a shortcut to call a standardized formatter is a very popular feature in many languages, also not hard to understand the appeal:
- cargo fmt
- go fmt
- deno fmt
- dart format
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`uv` isn't a package manager (that's the `uv-pip` sub command), it's a project manager. It's meant to manage all aspects of the project.
I love ruff and I love uv and I’m sure I will ty as soon as it’s ready but please keep them separate.
Cool. I want a do it all python tool. Ruff is great. Having it out of the box with uv is great. Less crap to mess with. I haven’t tried ty yet, but looking forward to not having to mess with pyright.
Wary of the vc funded aspect though…
Every single time someone asks "why?" in this thread, the answer is "well cargo does it too". Not sure what to think about that.
Not all devs have very deep knowledge of the ecosystem, some will get to use a tool only if it's part of the default set of tools they're provided. Plus, it saves on memorizing a name if you only use python once in a long while. There just isn't much of a reason not to.
I landed in python last year, the pre uv time for me. The language itself is fine, but the project organization sucked. What kind of folder structure to choose? Do I use pip, env, pipenv, poetry? How to format, and with which settings? I've read tens of blog post, all giving different choices, all equally reasonable, all having some downsides.
The great thing about uv is not that their choices are best, it's that the choices have been made, the gordian knots cut. There is a good enough standard to build upon. Future python projects will look a lot more like each other, and less time will be wasted on organizational minutiae.
As someone who has worked on package managers quite a bit in the past, and for that examined prior art across package managers, that's because Cargo is doing things very well on almost all fronts. Partially because of their RFC process and partially because they have the luxury of being a "newer" package manager that doesn't have to live with ecosystem baggage going many decades back.
There are/were definitely some weaker spots with Cargo (e.g. private registry support was meh for some time), but if one were tasked to build a package manager and were only allowed to pick a single one to take inspration from, Cargo is definitely the way to go.
“Cargo does it” is a shortcut for “yes, it’s fucking good”.
the python crowd sure likes reinventing formatters every handful of years huh
uv is taking bun's route and just adding features "willy-nilly"?
Excellent. Love it. Keep on at it, guys.
Anyone from uv reading this? please scrap this thing, there is a separate formatter ruff that anyone ll use if they want a formatter. please do not complicate stuff. ruff ll come with its own configuration. this will have its own config at some point. potential rule clashes, ignore plugins. please do not go in this direction
A clean alternative: automatically adding ruff as a tool when creating a new pyproject.toml file, with a command line flag to opt out for the minority who know they don't intend to use ruff. For the majority of users, simplicity is worth an accidental download.
Ruff and uv are written by the same company, astral
this command is more or less an alias for calling Ruff, it's quite explicitly written in the article
I recognize that uv is very popular but it still feels faddish.
I don't want my package manager to format anything.
I don't want my package manager to lint anything.
I don't want my package manager to `run` anything.
I don't want my package manager to even manage environments (yes yes this one is a bit extreme).
I want to have single purpose tools that work together well.
This way I can have a flexible, composable toolchain that can both adapt to me and my specific project.
For example, I like conda, pip, ruff, mypy, flake8. Someone else might like venv, pip, black, pyright, flake8.
This is the heart of the Unix Philosophy and I feel like it's a philosophy each software community has to reject, suffer due to that rejection, and re-adopt on a regular basis. I'd rather we skip the suffering bit.
As someone using formating tools on IDE since the 1990's and UNIX indent as well, I really don't get the hype for formatters.
Even moreso in the LLM age of tooling and coding agents.
It's a minor issues in teams where people use inconsistent formatting. This causes needless complications when merging code and additional work related to resolving conflicts that shouldn't exist to begin with.
Some languages (Go, Rust) have essentially solved this issue to the point where blindly running the formatters these languages have solves the problem and is uncontroversial.
Sadly, the language of choice for me (Kotlin) has a big unaddressed problem here where what the IDE does for formatting and what independent formatting tools do are two things that are hard to align for mostly the historical reasons that what the IDE does is fragmented over different bits of code that don't listen to the same configuration. There is a lot of variation in preferences for indentation, where to put new lines, line length, what order to put imports in, which imports to use wildcards for (if any at all), etc. Particularly imports are a problem because the bit of code that organizes imports is separate from the bit of code that formats code in the IDE.
The common solution of using IDE plugins to work around this is a bit of a kludge. The proper solution would be a more sane way to just make the IDE externally configurable so that build tools can make the IDE do exactly the same as what they do without requiring users to manually configure their IDEs just right by installing plugins or fiddling with configuration. This stuff should not be user controllable if there is a build file that defines the proper formatting.
Coding agents actually add to this problem. Because getting those to stick to formatting conventions is tricky. Unless you have tools that just fix that properly.
So good change in uv and probably something I'd be using on my next python project (I do those once in a while).
Easily solvable with SCM pre-commit hooks, at very least since CVS days.
All major IDEs allow to save the format configurations, which can be stored on the repo alongside the code as the team official's configuration.
Coding agents solve this problem in that eventually all programming languages will be as relevant as mastering Assembly is nowadays.
I already do stuff in low code/no code, that in the past I would be manually writing code to sort out those issues.
In the meantime, you can also ask them to format generated code in whatever way one feels like it.
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I hope for uv's sake, that the formatting is always optional and that it is not "opinionated" (read: half asses and no way to configure it), but configurable. And if we get into that, well, it's a whole different tool, that they are trying to put into uv. Seems like a bad idea.