diff --git a/ChangeLog b/ChangeLog index e575805e70..eb6838f518 100644 --- a/ChangeLog +++ b/ChangeLog @@ -242,6 +242,11 @@ What's New in Pylint 2.13.8? ============================ Release date: TBA +* Fix a false positive for ``undefined-loop-variable`` for a variable used in a lambda + inside the first of multiple loops. + + Closes #6419 + * Fix a crash when linting a file that passes an integer ``mode=`` to ``open`` diff --git a/doc/whatsnew/2.13.rst b/doc/whatsnew/2.13.rst index 2935bddb5b..c5a2e4e527 100644 --- a/doc/whatsnew/2.13.rst +++ b/doc/whatsnew/2.13.rst @@ -615,6 +615,11 @@ Other Changes Closes #5930 +* Fix a false positive for ``undefined-loop-variable`` for a variable used in a lambda + inside the first of multiple loops. + + Closes #6419 + * Fix a crash when linting a file that passes an integer ``mode=`` to ``open`` diff --git a/pylint/checkers/variables.py b/pylint/checkers/variables.py index 2fa33f3246..a309b329d0 100644 --- a/pylint/checkers/variables.py +++ b/pylint/checkers/variables.py @@ -2198,7 +2198,10 @@ def _loopvar_name(self, node: astroid.Name) -> None: # the usage is safe because the function will not be defined either if # the variable is not defined. scope = node.scope() - if isinstance(scope, nodes.FunctionDef) and any( + # FunctionDef subclasses Lambda due to a curious ontology. Check both. + # See https://github.com/PyCQA/astroid/issues/291 + # TODO: Revisit when astroid 3.0 includes the change + if isinstance(scope, nodes.Lambda) and any( asmt.scope().parent_of(scope) for asmt in astmts ): return diff --git a/tests/functional/u/undefined/undefined_loop_variable.py b/tests/functional/u/undefined/undefined_loop_variable.py index 956773e310..0270c6b532 100644 --- a/tests/functional/u/undefined/undefined_loop_variable.py +++ b/tests/functional/u/undefined/undefined_loop_variable.py @@ -103,3 +103,23 @@ def handle_line(layne): ] for item in lst ] + + +def lambda_in_first_of_two_loops(): + """https://github.com/PyCQA/pylint/issues/6419""" + my_list = [] + for thing in my_list: + print_it = lambda: print(thing) # pylint: disable=cell-var-from-loop + print_it() + + for thing in my_list: + print(thing) + + +def variable_name_assigned_in_body_of_second_loop(): + for alias in tuple(bigger): + continue + for _ in range(3): + alias = True + if alias: + print(alias)