Python core

House Python stack: uv for env and deps, ruff for lint and format, mypy strict-leaning, pytest, pydantic v2 at IO boundaries. Route to the matching reference for framework or data work.

Tooling

uv is the default — replaces pip, venv, virtualenv, and pip-tools:

uv init                    # new project, writes pyproject.toml
uv add fastapi             # add a runtime dep
uv add --dev pytest ruff mypy
uv sync                    # install from lockfile
uv run pytest              # run inside the project's venv
uv python pin 3.12         # pin the interpreter

Commit uv.lock. Use pip or poetry only when a project already runs on one of them — don't migrate an incumbent project unasked.