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Fix FP for invalid-name with typing.Final on dataclass fields #10797

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Fix FP for invalid-name with typing.Final on dataclass fields #10797

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4 changes: 4 additions & 0 deletions doc/whatsnew/fragments/10790.false_positive
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Original file line number Diff line number Diff line change
@@ -0,0 +1,4 @@
Fix a false positive for ``invalid-name`` where a dataclass field typed with ``Final``
was evaluated against the ``class_const`` regex instead of the ``class_attribute`` regex.

Closes #10790
11 changes: 8 additions & 3 deletions pylint/checkers/base/name_checker/checker.py
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Expand Up @@ -552,9 +552,14 @@ def visit_assignname( # pylint: disable=too-many-branches,too-many-statements
elif isinstance(frame, nodes.ClassDef) and not any(
frame.local_attr_ancestors(node.name)
):
if utils.is_enum_member(node) or utils.is_assign_name_annotated_with(
node, "Final"
):
if utils.is_assign_name_annotated_with_class_var_typing_name(node, "Final"):
self._check_name("class_const", node.name, node)
elif utils.is_assign_name_annotated_with(node, "Final"):
if frame.is_dataclass:
self._check_name("class_attribute", node.name, node)
else:
self._check_name("class_const", node.name, node)
elif utils.is_enum_member(node):
self._check_name("class_const", node.name, node)
else:
self._check_name("class_attribute", node.name, node)
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16 changes: 16 additions & 0 deletions pylint/checkers/utils.py
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Expand Up @@ -1762,6 +1762,22 @@ def is_assign_name_annotated_with(node: nodes.AssignName, typing_name: str) -> b
return False


def is_assign_name_annotated_with_class_var_typing_name(
node: nodes.AssignName, typing_name: str
) -> bool:
if not is_assign_name_annotated_with(node, "ClassVar"):
return False
annotation = node.parent.annotation
if isinstance(annotation, nodes.Subscript):
annotation = annotation.slice
if isinstance(annotation, nodes.Subscript):
annotation = annotation.value
match annotation:
case nodes.Name(name=n) | nodes.Attribute(attrname=n) if n == typing_name:
return True
return False


def get_iterating_dictionary_name(node: nodes.For | nodes.Comprehension) -> str | None:
"""Get the name of the dictionary which keys are being iterated over on
a ``nodes.For`` or ``nodes.Comprehension`` node.
Expand Down
9 changes: 6 additions & 3 deletions tests/functional/i/invalid/invalid_name/invalid_name_with_final_typing.py
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Expand Up @@ -3,7 +3,7 @@
# pylint: disable=missing-class-docstring, missing-function-docstring

from dataclasses import dataclass
from typing import Final
from typing import ClassVar, Final

module_snake_case_constant: Final[int] = 42 # [invalid-name]
MODULE_UPPER_CASE_CONSTANT: Final[int] = 42
Expand All @@ -17,8 +17,11 @@ def function() -> None:

@dataclass
class Class:
class_snake_case_constant: Final[int] = 42 # [invalid-name]
CLASS_UPPER_CASE_CONSTANT: Final[int] = 42
class_snake_case_constant: ClassVar[Final[int]] = 42 # [invalid-name]
CLASS_UPPER_CASE_CONSTANT: ClassVar[Final[int]] = 42

field_annotated_with_final: Final[int] = 42
FIELD_ANNOTATED_WITH_FINAL: Final[int] = 42 # this could emit invalid-name eventually.
Comment on lines +23 to +24
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@Pierre-Sassoulas Pierre-Sassoulas Jan 13, 2026

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Reading PEP591 I felt that Final was supposed to indicate a constant. Note that most of the Final annotated variable are in UPPERCASE here : https://peps.python.org/pep-0591/#id2 (with a notable exception of the mutable list and a 2 int vector example). Also here in the "updated documentation" linked in PEP 591 : https://docs.python.org/3/library/typing.html#typing.Final. Could you explain your reasoning for forbidding uppercase ?

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@jacobtylerwalls jacobtylerwalls Jan 13, 2026

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Good question. I can remove the editorial comment. I don't think there's any plan to forbid upper cased final variables.

I replied to the reporter, if it helps:

I'm a little surprised we enforce snake_case for function variables annotated with Final, since it seems like they should be UPPER_CASE, which would conflict with the example here, but I take it we should just be liberal and allow either.


def method(self) -> None:
method_snake_case_constant: Final[int] = 42
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2 changes: 1 addition & 1 deletion tests/functional/i/invalid/invalid_name/invalid_name_with_final_typing.txt
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
invalid-name:8:0:8:26::"Constant name ""module_snake_case_constant"" doesn't conform to UPPER_CASE naming style":HIGH
invalid-name:14:4:14:32:function:"Variable name ""FUNCTION_UPPER_CASE_CONSTANT"" doesn't conform to snake_case naming style":HIGH
invalid-name:20:4:20:29:Class:"Class constant name ""class_snake_case_constant"" doesn't conform to UPPER_CASE naming style":HIGH
invalid-name:25:8:25:34:Class.method:"Variable name ""METHOD_UPPER_CASE_CONSTANT"" doesn't conform to snake_case naming style":HIGH
invalid-name:28:8:28:34:Class.method:"Variable name ""METHOD_UPPER_CASE_CONSTANT"" doesn't conform to snake_case naming style":HIGH