Python

The Python scaffold uses uv, Ruff, a local Flake8 plugin for Anvil rules, mypy, pytest coverage, dependency audit, dead-code checks, CRAP scoring, and mutation testing.

uv pip install -e ".[dev]"
make check

Useful generated targets include make lint, make typecheck, make test, make coverage, make audit, make check, and make quality.

What gets wired in

Anvil adds Ruff rules, a local editable Flake8 plugin under tools/flake8-plugin/, mypy strict type checking, pytest coverage, Vulture dead-code checks, pip-audit, mutmut, gitleaks scanning, and a generated Nix shell with Python and uv.

The Python checks focus on maintainability pressure for agent-authored code: explicit error handling, structured logging, meaningful tests, file/function size limits, exported type/error/constant organization, and dependency risk.

Seed/reference code

Greenfield projects receive src/seed/ and tests/ examples that model package structure, typed errors, constants, enums, and tests. Existing projects skip seed code when Python source already exists.