List of keywords you searched for before creating this issue. Write them down here so that others can find this issue more easily and help provide feedback.

• "PRL0913"
• "too-many-arguments"
• "self"
• "cls"
• "false positve"

A minimal code snippet that reproduces the bug.

class DemoClass:
    def __init__(self, one, two, three, four, five):
        pass

    @classmethod
    def bar(cls, one, two, three, four, five):
        pass

    @staticmethod
    def foo(one, two, three, four, five):
        pass

The command you invoked (e.g., ruff /path/to/file.py --fix), ideally including the --isolated flag.

ruff check foo.py --isolated --select PLR0913

This produles the following output:

(.venv) ~\PycharmProjects\test git:[dev]
ruff check foo.py --isolated --select PLR0913
foo.py:2:9: PLR0913 Too many arguments in function definition (6 > 5)
  |
1 | class DemoClass:
2 |     def __init__(self, one, two, three, four, five):
  |         ^^^^^^^^ PLR0913
3 |         pass
  |

foo.py:6:9: PLR0913 Too many arguments in function definition (6 > 5)
  |
5 |     @classmethod
6 |     def bar(cls, one, two, three, four, five):
  |         ^^^ PLR0913
7 |         pass
  |

Found 2 errors.

Apparently, ruff considers self and cls when computing the number of arguments. However, these arguments are mandatory anyway, are not visible to the consumer of these methods and don't introduce any maintenance overhead. I propose that ruff ignores them.

The current Ruff settings (any relevant sections from your pyproject.toml). used --isolated flag above

The current Ruff version (ruff --version): ruff 0.5.1