astral-sh
`PLR6301` doesn't consider base class methods
Consider the following simple example (and common python pattern in general) in django:
to build a management command, one simply inherits from BaseCommand and overrides some methods:
from django.core.management.base import BaseCommand, CommandError
class Command(BaseCommand):
def add_arguments(self, parser):
pass
def handle(self, *args, **options):
pass
Currently both of these are marked by ruff 0.5.0 as PLR6301 (https://docs.astral.sh/ruff/rules/no-self-use/).
I tell a lie: I copy pasted this "minimal" example into a new file and there is no warning 😁 However the moment I add actual code to the methods, the warnings show up:
from django.core.management.base import BaseCommand, CommandError
class Command(BaseCommand):
def add_arguments(self, parser):
parser.add_argument("--id", required=True, type=int, help="Page id")
def handle(self, *args, **options):
pass
Out of curiosity I installed pylint and ran it on the file and it does not trigger this message...
[tool.ruff]
line-length = 100
[tool.ruff.lint]
preview = true
select = [
"A", # https://pypi.org/project/flake8-builtins/
"B", # https://pypi.org/project/flake8-bugbear/
"C4", # https://pypi.org/project/flake8-comprehensions/
"C90", # https://pypi.org/project/mccabe/
"DJ", # https://pypi.org/project/flake8-django/
"DTZ", # https://pypi.org/project/flake8-datetimez/
"E", "W", # https://pypi.org/project/pycodestyle/
"F", # https://pypi.org/project/pyflakes/
"FURB", # https://pypi.org/project/refurb/
"G", # https://pypi.org/project/flake8-logging-format/
"I", # https://pypi.org/project/isort/
"N", # https://pypi.org/project/pep8-naming/
"PERF", # https://pypi.org/project/perflint/
"PIE", # https://pypi.org/project/flake8-pie/
"PL", # https://pypi.org/project/pylint/
"PT", # https://pypi.org/project/flake8-pytest-style/
"PTH", # https://pypi.org/project/flake8-use-pathlib/
"RET", # https://pypi.org/project/flake8-return/
"RUF", # Ruff-specific rules
"S", # https://pypi.org/project/flake8-bandit/
"SIM", # https://pypi.org/project/flake8-simplify/
"UP", # https://pypi.org/project/pyupgrade/
]
ignore = ["RUF012"]
[tool.ruff.lint.isort]
# Use a single line between direct and from import.
lines-between-types = 1
section-order = ["future", "standard-library", "third-party", "django", "wagtail", "first-party", "local-folder"]
[tool.ruff.lint.isort.sections]
# Group all Django imports into a separate section.
"django" = ["django"]
"wagtail" = ["wagtail"]
I think this is because we're missing a check for method overrides from the base class which is done by Pylint (https://github.com/pylint-dev/pylint/blob/c8351395008e586170b0dda680594ba29b8fe0ef/pylint/extensions/no_self_use.py#L90).
We could possibly add this check with the current semantic model but it will only work if the base class is in the same file. In your case, it's being imported from another module which will require multifile analysis.
Thank you for the quick analysis. This rule is clearly in preview mode, but in my understanding until multifile analysis is being done, even simple cases like this will be false positives. What is ruff's rule policy for these cases?
The general suggestion for now is to mark such methods as overrides: https://play.ruff.rs/d0b3d8f4-1706-4a22-b19f-ea28c7acaacc
I ran into something similar with a class that immediately raises a NotImplementedError.
I've previously raised a similar issue (#12427) and there it was fixed using some generic definition of a "base class stub". I wonder whether that same definition could be used to determine when to flag PLR6301 and when not to.
I have the same issue with a different library.
I would like to just add a # noqa: PLR6301 to the whole class:
class Command(BaseCommand): # noqa: PLR6301
def add_arguments(self, parser):
print(1)
def handle(self, *args, **options):
print(2)
