Dependencies

Dependencies are managed with uv and declared in pyproject.toml:

• Runtime dependencies ([project] dependencies) are what users install: NumPy and opt_einsum. Keep this list short; every entry is imposed on every downstream project.
• Extras ([project.optional-dependencies]) enable optional features in production: gpu-nvidia and gpu-rocm add CuPy.
• Dependency groups ([dependency-groups]) are for development only and are never installed by users:
  • test: pytest, its plugins, and quimb to build reference networks;
  • bench: what the scripts under benches/ import (cyclopts, quimb, scipy);
  • dev: the linters, type checker and hooks, plus test and bench;
  • interactive: Jupyter and plotting for notebooks;
  • docs: what this site's build needs, plus test and interactive.

Why uv?Copy Anchor Link

• Its lockfile is compact and multi-platform.
• It gives granular control over which index each dependency comes from, which matters with private indexes.
• It is very fast.

Changing dependenciesCopy Anchor Link

1. Edit pyproject.toml.
2. Run uv sync --all-groups to update the environment and regenerate uv.lock, and commit both files. The uv-lock hook fails if they disagree.

Version constraintsCopy Anchor Link

Declare the oldest version that works rather than the one you happen to have installed: a high floor stops users from installing src_method next to anything that has not caught up yet. Give every direct dependency a floor, including those in dependency groups.

Floors are tested rather than assumed: the test workflow has a job on the oldest supported Python that resolves every direct dependency to its lowest allowed version (UV_RESOLUTION=lowest-direct). To reproduce it locally:

export UV_RESOLUTION=lowest-direct
uv sync --python 3.11 --no-dev --group test
uv run --no-sync pytest -m "not slow"

--no-sync matters: a plain uv run would also install the dev group, at its lowest versions. Do not commit the uv.lock this produces. Raise a floor only when the code needs a newer feature or the lowest-resolution job fails.

Tool pinsCopy Anchor Link

ruff and ty are pinned twice, in the dev group and in prek.toml. The check-tool-pins hook fails if the two disagree; update-ruff.yml and update-ty.yml bump both pins of their tool together.