uv: Unified Python packaging (via) Huge new release from the Astral team today. uv 0.3.0 adds a bewildering array of new features, as part of their attempt to build "Cargo, for Python".
It's going to take a while to fully absorb all of this. Some of the key new features are:
uv tool run cowsay
, aliased touvx cowsay
- a pipx alternative that runs a tool in its own dedicated virtual environment (tucked away in~/Library/Caches/uv
), installing it if it's not present. It has a neat--with
option for installing extras - I tried that just now withuvx --with datasette-cluster-map datasette
and it ran Datasette with thedatasette-cluster-map
plugin installed.- Project management, as an alternative to tools like Poetry and PDM.
uv init
creates apyproject.toml
file in the current directory,uv add sqlite-utils
then creates and activates a.venv
virtual environment, adds the package to thatpyproject.toml
and adds all of its dependencies to a newuv.lock
file (like this one). Thatuv.lock
is described as a universal or cross-platform lockfile that can support locking dependencies for multiple platforms. - Single-file script execution using
uv run myscript.py
, where those scripts can define their own dependencies using PEP 723 inline metadata. These dependencies are listed in a specially formatted comment and will be installed into a virtual environment before the script is executed. - Python version management similar to pyenv. The new
uv python list
command lists all Python versions available on your system (including detecting various system and Homebrew installations), anduv python install 3.13
can then install a uv-managed Python using Gregory Szorc's invaluable python-build-standalone releases.
It's all accompanied by new and very thorough documentation.
The paint isn't even dry on this stuff - it's only been out for a few hours - but this feels very promising to me. The idea that you can install uv
(a single Rust binary) and then start running all of these commands to manage Python installations and their dependencies is very appealing.
If you’re wondering about the relationship between this and Rye - another project that Astral adopted solving a subset of these problems - this forum thread clarifies that they intend to continue maintaining Rye but are eager for uv
to work as a full replacement.
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