diff options
Diffstat (limited to 'pylint/checkers/refactoring/implicit_booleaness_checker.py')
| -rw-r--r-- | pylint/checkers/refactoring/implicit_booleaness_checker.py | 36 |
1 files changed, 19 insertions, 17 deletions
diff --git a/pylint/checkers/refactoring/implicit_booleaness_checker.py b/pylint/checkers/refactoring/implicit_booleaness_checker.py index d3ef542a1..ad072e3f8 100644 --- a/pylint/checkers/refactoring/implicit_booleaness_checker.py +++ b/pylint/checkers/refactoring/implicit_booleaness_checker.py @@ -66,24 +66,28 @@ class ImplicitBooleanessChecker(checkers.BaseChecker): "C1802": ( "Do not use `len(SEQUENCE)` without comparison to determine if a sequence is empty", "use-implicit-booleaness-not-len", - "Used when Pylint detects that len(sequence) is being used " - "without explicit comparison inside a condition to determine if a sequence is empty. " - "Instead of coercing the length to a boolean, either " - "rely on the fact that empty sequences are false or " - "compare the length against a scalar.", + "Empty sequences are considered false in a boolean context. You can either" + " remove the call to 'len' (``if not x``) or compare the length against a" + "scalar (``if len(x) > 1``).", {"old_names": [("C1801", "len-as-condition")]}, ), "C1803": ( '"%s" can be simplified to "%s", if it is strictly a sequence, as an empty %s is falsey', "use-implicit-booleaness-not-comparison", - "Used when Pylint detects that collection literal comparison is being " - "used to check for emptiness; Use implicit booleaness instead " - "of a collection classes; empty collections are considered as false", + "Empty sequences are considered false in a boolean context. Following this" + " check blindly in weakly typed code base can create hard to debug issues." + " If the value can be something else that is falsey but not a sequence (for" + " example ``None``, an empty string, or ``0``) the code will not be " + "equivalent.", ), "C1804": ( '"%s" can be simplified to "%s", if it is striclty a string, as an empty string is falsey', "use-implicit-booleaness-not-comparison-to-string", - "Used when Pylint detects comparison to an empty string constant.", + "Empty string are considered false in a boolean context. Following this" + " check blindly in weakly typed code base can create hard to debug issues." + " If the value can be something else that is falsey but not a string (for" + " example ``None``, an empty sequence, or ``0``) the code will not be " + "equivalent.", { "default_enabled": False, "old_names": [("C1901", "compare-to-empty-string")], @@ -92,7 +96,11 @@ class ImplicitBooleanessChecker(checkers.BaseChecker): "C1805": ( '"%s" can be simplified to "%s", if it is strictly an int, as 0 is falsey', "use-implicit-booleaness-not-comparison-to-zero", - "Used when Pylint detects comparison to a 0 constant.", + "0 is considered false in a boolean context. Following this" + " check blindly in weakly typed code base can create hard to debug issues." + " If the value can be something else that is falsey but not an int (for" + " example ``None``, an empty string, or an empty sequence) the code will not be " + "equivalent.", {"default_enabled": False, "old_names": [("C2001", "compare-to-zero")]}, ), } @@ -223,12 +231,6 @@ class ImplicitBooleanessChecker(checkers.BaseChecker): ) def _check_compare_to_string(self, node: nodes.Compare) -> None: - """Checks for comparisons to empty string. - - Most of the time you should use the fact that empty strings are false. - An exception to this rule is when an empty string value is allowed in the program - and has a different meaning than None! - """ _operators = {"!=", "==", "is not", "is"} # note: astroid.Compare has the left most operand in node.left while the rest # are a list of tuples in node.ops the format of the tuple is @@ -257,7 +259,7 @@ class ImplicitBooleanessChecker(checkers.BaseChecker): if error_detected: suggestion = f"not {node_name}" if op_2 in {"==", "is"} else node_name self.add_message( - "compare-to-empty-string", + "use-implicit-booleaness-not-comparison-to-string", args=(node.as_string(), suggestion), node=node, confidence=HIGH, |