Linting and code quality

Code can be linted and quality-checked with the command

just check

Note that this requires the prek hooks to be installed.

This command will run the following tools:

ruff

ruff is used to lint and format the code, and it is configured through pyproject.toml with comprehensive rules covering security, style, best practices, and documentation:

[tool.ruff]
line-length = 120
fix = true

[tool.ruff.lint]
preview = true
select = [
    "FAST", # FastAPI - FastAPI specific rules
    "YTT",  # flake8-2020 - checks for Python 2020 best practices
    "ANN",  # flake8-annotations - enforces type annotation style
    "S",    # flake8-bandit - security issues
    "BLE",  # flake8-blind-except – flags bare excepts
    "FBT",  # flake8-boolean-trap – potential pitfalls with booleans
    "B",    # flake8-bugbear - common bug patterns
    "A",    # flake8-builtins - misuse of python builtin names
    "C4",   # flake8-comprehensions - best practices in comprehensions
    "DTZ",  # flake8-datetimez – requires timezone-aware datetime objects
    "T10",  # flake8-debugger – debugger statements (e.g. pdb)
    "SIM",  # flake8-simplify
    "EM",   # flake8-errmsg – error message style
    "EXE",  # flake8-executable – executable file checks
    "FA",   # flake8-future-annotations – future import for annotations
    "ISC",  # flake8-implicit-str-concat – warns on implicit string concatenation
    "ICN",  # flake8-import-conventions – enforces conventional import aliases
    "LOG",  # flake8-logging – proper logging usage
    "G",    # flake8-logging-format – logging format string issues
    "INP",  # flake8-no-pep420 – warns against non-PEP420 namespace usage
    "PIE",  # flake8-pie – Python improvement suggestions
    "PYI",  # flake8-pyi – checks for type stub (.pyi) consistency
    "PT",   # flake8-pytest-style – pytest best practices
    "Q",    # flake8-quotes – enforces quote style consistency
    "RSE",  # flake8-raise – proper raise statement usage
    "RET",  # flake8-return – return statement issues
    "SLF",  # flake8-self – flags instance methods that don't use self
    "SLOT", # flake8-slots – suggests use of __slots__ where appropriate
    "TID",  # flake8-tidy-imports – enforces specific import styles
    "TC",   # flake8-type-checking – proper import of typing in type checks
    "INT",  # flake8-gettext – checks for proper internationalization usage
    "ARG",  # flake8-unused-arguments – flags unused function arguments
    "PTH",  # flake8-use-pathlib – encourages pathlib over os.path
    "TD",   # flake8-todos – flags TODO comments
    "FIX",  # flake8-fixme – flags FIXME comments
    "FLY",  # Flynt - f-string conversion suggestions
    "I",    # isort - import ordering checks
    "C90",  # mccabe - complexity metric for functions
    "NPY",  # NumPy-specific rules
    "PD",   # pandas-vet – pandas-specific code practices
    "N",    # PEP8 Naming – naming conventions
    "PERF", # Perflint – performance-related checks
    "E",    # pycodestyle errors
    "W",    # pycodestyle warnings
    "DOC",  # pydoclint - docstring style
    "D",    # pydocstyle - docstring formatting
    "F",    # pyflakes - detects syntax errors and basic mistakes
    "PGH",  # pygrep-hooks - custom grep hooks for linting
    "UP",   # pyupgrade - upgrades syntax to newer Python versions
    "RUF",  # Ruff-specific rules
    "TRY",  # Tryceratops – try/except usage suggestions
]
ignore = [
    "E501", # line-too-long
    "S311", # suspicious-non-cryptographic-random-usage
    "D107", # undocumented-public-init
]

[tool.ruff.lint.pydocstyle]
convention = "google"

[tool.ruff.lint.per-file-ignores]
"tests/*" = ["D", "S101", "ANN", "BLE", "TRY"]

This comprehensive rule set helps ensure code quality, security, and maintainability across your project.

mypy

mypy is used for static type checking, and it's configuration can be edited in pyproject.toml.

[tool.mypy]
disallow_untyped_defs = true
disallow_any_unimported = true
no_implicit_optional = true
check_untyped_defs = true
warn_return_any = true
warn_unused_ignores = true
show_error_codes = true
exclude = [
    '\.venv',
    '{{cookiecutter.project_name}}',
    'tests'
]

ty

ty is an extremely fast type checker (and language server) that can be used instead of mypy, and it's configuration can be edited in pyproject.toml.

[tool.ty.environment]
python = "./.venv"
python-version = "3.10"

deptry

deptry is used to check the code for dependency issues, and it can be configured by adding a [tool.deptry] section in pyproject.toml. For more information, see this section documentation of deptry.

Github Actions

If include_github_actions is set to "y", code formatting is checked for every merge request, every merge to main, and every release.