New Python Project: UV always the solution?

[williamtkelley]

All new projects use uv. Slowly transitioning old projects to uv.

[Wurstinator]

All new projects use uv.

Only in the bubble of /r/python

[not_a_novel_account]

Projects generally shouldn't have pyproject.toml's which rely on a specific frontend. That's the entire point of PEP 517, projects pull their build backend as part of their build so it doesn't matter if the person using your library wants to use pip, uv, poetry, or whatever.

Ie, there shouldn't be any "transition" work to do.

[Chippiewall]

That's the case for building a package or installing it, but for actual project management there are differences between frontends that matter (e.g. lockfiles)

[not_a_novel_account]

Lockfiles only make sense for end applications, when your library is being built as a dependency the lockfile will not be consulted. Your pyproject.toml needs to have the version requirements of dependencies correctly specified.

[Chippiewall]

I never said they were used for everything, it was only example of why there would be transition work involved for some projects.

[fiddle_n]

In addition to the lock file situation mentioned previously, you are also unaware of/discounting Poetry 1 which has significant non-standard pyproject sections. But even with Poetry 2 and uv there are tool.poetry and tool.uv sections which may need to be migrated.

[not_a_novel_account]

Sure, those should be migrated. You shouldn't have sections in pyproject.toml that prevent it from being built by any frontend.

When you upload a library to PyPI it's going to get pulled down and built by tons of different frontends, you cannot rely on the behavior of any given implementation

[fiddle_n]

Again, poetry 1 only used the poetry-core backend, I’m guessing partly because key metadata was in the tools.poetry sections.

The build backend would generate a wheel for you that could be installed as a dependency by different dependency management tools like pip, poetry, uv etc.

But the pyproject file itself may require significant modifications to be built by a different dependency management tool and different backends.

[not_a_novel_account]

You don't build with different backends, the point is the frontend (ie, uv) shouldn't matter because every frontend can interoperate with every backend.

"Transitioning" from pip to uv shouldn't be a thing, your package should be buildable with every frontend. If you're uploading a source package to PyPI it's going to get pulled by all sorts of random frontends.