# Ruff config — the single source of truth for Python style/lint in this repo.
# See CLAUDE.md ("Coding principles") for the conventions this enforces.
line-length = 120
target-version = "py39"
extend-exclude = ["frontend", "**/__pycache__"]

[lint]
# E/W: pycodestyle, F: pyflakes (unused imports/vars, f-strings w/o placeholders),
# I: import sorting. Deliberately conservative — no opinionated reformatting rules.
select = ["E", "W", "F", "I"]
# Line length is owned by the formatter; a handful of URLs/strings can't wrap, so
# don't fail lint on length.
ignore = ["E501"]

[lint.per-file-ignores]
# conftest must insert the repo root onto sys.path before importing project modules.
"tests/conftest.py" = ["E402"]

[format]
# The codebase is intentionally mixed (single-quoted keys/literals, double-quoted
# f-strings/messages); preserve that rather than churn every string.
quote-style = "preserve"