Simon Willison’s Weblog

uv: Python packaging in Rust (via) “uv is an extremely fast Python package installer and resolver, written in Rust, and designed as a drop-in replacement for pip and pip-tools workflows.”

From Charlie Marsh and Astral, the team behind Ruff, who describe it as a milestone in their pursuit of a “Cargo for Python”.

Also in this announcement: Astral are taking over stewardship of Armin Ronacher’s Rye packaging tool, another Rust project.

uv is reported to be 8-10x faster than regular pip, increasing to 80-115x faster with a warm global module cache thanks to copy-on-write and hard links on supported filesystems—which saves on disk space too.

It also has a --resolution=lowest option for installing the lowest available version of dependencies—extremely useful for testing, I’ve been wanting this for my own projects for a while.

Also included: “uv venv”—a fast tool for creating new virtual environments with no dependency on Python itself.