(🐞) bad unnecessary-dunder-call report for object.__getattribute__(self within a __getattribute__ implementation

[KotlinIsland]

class A:
    a = 1

    def __getattribute__(self, item):
        return object.__getattribute__(self, item)  # PLC2801 Unnecessary dunder call to `__getattribute__`. Access attribute directly or use getattr built-in function..

A().a

Ah yes, better use getattr built-in function..

class A:
    a = 1

    def __getattribute__(self, item):
        return getattr(self, item)

A().a
#   File "C:\Users\charlie_marsh(parody)\rust_based_python_typechecker\__init__.py", line 5, in __getattribute__
#    return getattr(self, item)
#           ^^^^^^^^^^^^^^^^^^^
#  [Previous line repeated 745 more times]
#RecursionError: maximum recursion depth exceeded

[charliermarsh]

What is going on with that filename lol

[randolf-scholz]

Other example of a false-positive:

class A:
    def __repr__(self):
        return "Prints this text"

a = A()
object.__repr__(a)  # PLC2801

Generally, for T.__dunder__(obj, *args, **kwargs) to be redundant (assuming isinstance(T, type)), I think we necessarily need type(obj).__dunder__ is T.__dunder__ to be true?

[charliermarsh]

Need to understand how pylint handles this.

[charliermarsh]

So for one thing, they omit dunder calls within dunder methods.

[charliermarsh]

It looks like they also skip dunder calls on non-instantiated classes? Which includes object?

[bastimeyer]

So for one thing, they omit dunder calls within dunder methods.

This is the main cause of PLC2801 being raised in our project after updating ruff to 0.1.13.

Another false positive report (IMO) after upgrading to the latest version is the explicit call of dunder methods in test cases. Imagine a __getitem__ method which gets tested for a specific exception in a with pytest.raises(...) block. Ruff now wants me to use the subscript notation (foo[bar] instead of foo.__getitem__(bar)), which is then reported as a "statement without an effect" by other linters (like the one built into pycharm for example). Calling the __getitem__ method explicitly should be ok in test cases and shouldn't require an annotation for suppressing PLC2801.

[charliermarsh]

Yeah we can easily fix that part. The second part is harder and will require us to greatly limit the scope of the rule.

[charliermarsh]

(I'll fix the first part now.)