# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html # For details: https://github.com/PyCQA/pylint/blob/main/LICENSE # Copyright (c) https://github.com/PyCQA/pylint/blob/main/CONTRIBUTORS.txt from __future__ import annotations from itertools import zip_longest from typing import TYPE_CHECKING from astroid import nodes from pylint.checkers import BaseChecker from pylint.interfaces import HIGH if TYPE_CHECKING: from pylint.lint import PyLinter class LambdaExpressionChecker(BaseChecker): """Check for unnecessary usage of lambda expressions.""" name = "lambda-expressions" msgs = { "C3001": ( "Lambda expression assigned to a variable. " 'Define a function using the "def" keyword instead.', "unnecessary-lambda-assignment", "Used when a lambda expression is assigned to variable " 'rather than defining a standard function with the "def" keyword.', ), "C3002": ( "Lambda expression called directly. Execute the expression inline instead.", "unnecessary-direct-lambda-call", "Used when a lambda expression is directly called " "rather than executing its contents inline.", ), } options = () def visit_assign(self, node: nodes.Assign) -> None: """Check if lambda expression is assigned to a variable.""" if isinstance(node.targets[0], nodes.AssignName) and isinstance( node.value, nodes.Lambda ): self.add_message( "unnecessary-lambda-assignment", node=node.value, confidence=HIGH, ) elif isinstance(node.targets[0], nodes.Tuple) and isinstance( node.value, (nodes.Tuple, nodes.List) ): # Iterate over tuple unpacking assignment elements and # see if any lambdas are assigned to a variable. # N.B. We may encounter W0632 (unbalanced-tuple-unpacking) # and still need to flag the lambdas that are being assigned. for lhs_elem, rhs_elem in zip_longest( node.targets[0].elts, node.value.elts ): if lhs_elem is None or rhs_elem is None: # unbalanced tuple unpacking. stop checking. break if isinstance(lhs_elem, nodes.AssignName) and isinstance( rhs_elem, nodes.Lambda ): self.add_message( "unnecessary-lambda-assignment", node=rhs_elem, confidence=HIGH, ) def visit_namedexpr(self, node: nodes.NamedExpr) -> None: if isinstance(node.target, nodes.AssignName) and isinstance( node.value, nodes.Lambda ): self.add_message( "unnecessary-lambda-assignment", node=node.value, confidence=HIGH, ) def visit_call(self, node: nodes.Call) -> None: """Check if lambda expression is called directly.""" if isinstance(node.func, nodes.Lambda): self.add_message( "unnecessary-direct-lambda-call", node=node, confidence=HIGH, ) def register(linter: PyLinter) -> None: linter.register_checker(LambdaExpressionChecker(linter))
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__pycache__ | Folder | 0755 |
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base | Folder | 0755 |
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classes | Folder | 0755 |
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refactoring | Folder | 0755 |
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__init__.py | File | 4.26 KB | 0644 |
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async.py | File | 3.83 KB | 0644 |
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bad_chained_comparison.py | File | 2.18 KB | 0644 |
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base_checker.py | File | 10.67 KB | 0644 |
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deprecated.py | File | 9.43 KB | 0644 |
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design_analysis.py | File | 21.62 KB | 0644 |
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dunder_methods.py | File | 3.43 KB | 0644 |
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ellipsis_checker.py | File | 1.97 KB | 0644 |
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exceptions.py | File | 26.05 KB | 0644 |
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format.py | File | 26.91 KB | 0644 |
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imports.py | File | 41.31 KB | 0644 |
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lambda_expressions.py | File | 3.38 KB | 0644 |
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logging.py | File | 15.84 KB | 0644 |
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mapreduce_checker.py | File | 1.08 KB | 0644 |
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method_args.py | File | 4.68 KB | 0644 |
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misc.py | File | 4.87 KB | 0644 |
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modified_iterating_checker.py | File | 7.67 KB | 0644 |
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nested_min_max.py | File | 3.63 KB | 0644 |
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newstyle.py | File | 4.46 KB | 0644 |
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non_ascii_names.py | File | 6.98 KB | 0644 |
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raw_metrics.py | File | 3.81 KB | 0644 |
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similar.py | File | 33.29 KB | 0644 |
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spelling.py | File | 16.17 KB | 0644 |
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stdlib.py | File | 31.28 KB | 0644 |
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strings.py | File | 40.28 KB | 0644 |
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threading_checker.py | File | 1.9 KB | 0644 |
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typecheck.py | File | 86.83 KB | 0644 |
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unicode.py | File | 18.05 KB | 0644 |
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unsupported_version.py | File | 2.93 KB | 0644 |
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utils.py | File | 77.26 KB | 0644 |
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variables.py | File | 126.57 KB | 0644 |
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