Add applicability notes for compare-to-empty-string/zero (#8592)

The extension `compare-to-empty-string` is only applicable when the expression being
compared is strictly a `str`.  The extension `compare-to-zero` is only applicable when
the expression being compared is strictly an `int`.

Author: Jason Lau

doc/user_guide/checkers/features.rst

@@ -893,14 +893,14 @@ Refactoring checker Messages
   Emitted when a single "return" or "return None" statement is found at the end
   of function or method definition. This statement can safely be removed
   because Python will implicitly return None
-:use-implicit-booleaness-not-comparison-to-zero (C1805): *"%s" can be simplified to "%s" as 0 is falsey*
-  Used when Pylint detects comparison to a 0 constant.
-:use-implicit-booleaness-not-comparison-to-string (C1804): *"%s" can be simplified to "%s" as an empty string is falsey*
+:use-implicit-booleaness-not-comparison-to-string (C1804): *"%s" can be simplified to "%s", if it is striclty a string, as an empty string is falsey*
   Used when Pylint detects comparison to an empty string constant.
-:use-implicit-booleaness-not-comparison (C1803): *'%s' can be simplified to '%s' as an empty %s is falsey*
+:use-implicit-booleaness-not-comparison (C1803): *"%s" can be simplified to "%s", if it is strictly a sequence, as an empty %s is falsey*
   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
+:use-implicit-booleaness-not-comparison-to-zero (C1805): *"%s" can be simplified to "%s", if it is strictly an int, as 0 is falsey*
+  Used when Pylint detects comparison to a 0 constant.
 :unneeded-not (C0113): *Consider changing "%s" to "%s"*
   Used when a boolean expression contains an unneeded negation.
 :consider-iterating-dictionary (C0201): *Consider iterating the dictionary directly instead of calling .keys()*

pylint/checkers/refactoring/implicit_booleaness_checker.py

@@ -74,14 +74,14 @@ class ImplicitBooleanessChecker(checkers.BaseChecker):
             {"old_names": [("C1801", "len-as-condition")]},
         ),
         "C1803": (
-            '"%s" can be simplified to "%s" as an empty %s is falsey',
+            '"%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",
         ),
         "C1804": (
-            '"%s" can be simplified to "%s" as an empty string is falsey',
+            '"%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.",
             {
@@ -90,7 +90,7 @@ class ImplicitBooleanessChecker(checkers.BaseChecker):
             },
         ),
         "C1805": (
-            '"%s" can be simplified to "%s" as 0 is falsey',
+            '"%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.",
             {"default_enabled": False, "old_names": [("C2001", "compare-to-zero")]},

tests/functional/u/use/use_implicit_booleaness_not_comparison.txt

@@ -1,32 +1,32 @@
-use-implicit-booleaness-not-comparison:14:7:14:21:github_issue_4774:"""bad_list == []"" can be simplified to ""not bad_list"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:22:3:22:20::"""empty_tuple == ()"" can be simplified to ""not empty_tuple"" as an empty tuple is falsey":HIGH
-use-implicit-booleaness-not-comparison:25:3:25:19::"""empty_list == []"" can be simplified to ""not empty_list"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:28:3:28:19::"""empty_dict == {}"" can be simplified to ""not empty_dict"" as an empty dict is falsey":HIGH
-use-implicit-booleaness-not-comparison:31:3:31:20::"""empty_tuple == ()"" can be simplified to ""not empty_tuple"" as an empty tuple is falsey":HIGH
-use-implicit-booleaness-not-comparison:34:3:34:19::"""empty_list == []"" can be simplified to ""not empty_list"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:37:3:37:19::"""empty_dict == {}"" can be simplified to ""not empty_dict"" as an empty dict is falsey":HIGH
-use-implicit-booleaness-not-comparison:42:11:42:18:bad_tuple_return:"""t == ()"" can be simplified to ""not t"" as an empty tuple is falsey":HIGH
-use-implicit-booleaness-not-comparison:46:11:46:18:bad_list_return:"""b == []"" can be simplified to ""not b"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:50:11:50:18:bad_dict_return:"""c == {}"" can be simplified to ""not c"" as an empty dict is falsey":HIGH
-use-implicit-booleaness-not-comparison:52:7:52:24::"""empty_tuple == ()"" can be simplified to ""not empty_tuple"" as an empty tuple is falsey":HIGH
-use-implicit-booleaness-not-comparison:53:7:53:23::"""empty_list == []"" can be simplified to ""not empty_list"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:54:7:54:23::"""empty_dict != {}"" can be simplified to ""empty_dict"" as an empty dict is falsey":HIGH
-use-implicit-booleaness-not-comparison:55:7:55:23::"""empty_tuple < ()"" can be simplified to ""not empty_tuple"" as an empty tuple is falsey":HIGH
-use-implicit-booleaness-not-comparison:56:7:56:23::"""empty_list <= []"" can be simplified to ""not empty_list"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:57:7:57:23::"""empty_tuple > ()"" can be simplified to ""not empty_tuple"" as an empty tuple is falsey":HIGH
-use-implicit-booleaness-not-comparison:58:7:58:23::"""empty_list >= []"" can be simplified to ""not empty_list"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:83:3:83:10::"""a == []"" can be simplified to ""not a"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:95:3:95:10::"""e == []"" can be simplified to ""not e"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:95:15:95:22::"""f == {}"" can be simplified to ""not f"" as an empty dict is falsey":HIGH
-use-implicit-booleaness-not-comparison:133:3:133:14::"""A.lst == []"" can be simplified to ""not A.lst"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:137:3:137:14::"""A.lst == []"" can be simplified to ""not A.lst"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:141:3:141:20::"""A.test(...) == []"" can be simplified to ""not A.test(...)"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:149:3:149:24::"""test_function(...) == []"" can be simplified to ""not test_function(...)"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:156:3:156:20::"""numpy_array == []"" can be simplified to ""not numpy_array"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:158:3:158:20::"""numpy_array != []"" can be simplified to ""numpy_array"" as an empty list is falsey":HIGH
-use-implicit-booleaness-not-comparison:160:3:160:20::"""numpy_array >= ()"" can be simplified to ""not numpy_array"" as an empty tuple is falsey":HIGH
-use-implicit-booleaness-not-comparison:185:3:185:13::"""data == {}"" can be simplified to ""not data"" as an empty dict is falsey":HIGH
-use-implicit-booleaness-not-comparison:187:3:187:13::"""data != {}"" can be simplified to ""data"" as an empty dict is falsey":HIGH
-use-implicit-booleaness-not-comparison:195:3:195:26::"""long_test == {}"" can be simplified to ""not long_test"" as an empty dict is falsey":HIGH
-use-implicit-booleaness-not-comparison:233:11:233:41:test_func:"""my_class.parent_function == {}"" can be simplified to ""not my_class.parent_function"" as an empty dict is falsey":HIGH
-use-implicit-booleaness-not-comparison:234:11:234:37:test_func:"""my_class.my_property == {}"" can be simplified to ""not my_class.my_property"" as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:14:7:14:21:github_issue_4774:"""bad_list == []"" can be simplified to ""not bad_list"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:22:3:22:20::"""empty_tuple == ()"" can be simplified to ""not empty_tuple"", if it is strictly a sequence, as an empty tuple is falsey":HIGH
+use-implicit-booleaness-not-comparison:25:3:25:19::"""empty_list == []"" can be simplified to ""not empty_list"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:28:3:28:19::"""empty_dict == {}"" can be simplified to ""not empty_dict"", if it is strictly a sequence, as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:31:3:31:20::"""empty_tuple == ()"" can be simplified to ""not empty_tuple"", if it is strictly a sequence, as an empty tuple is falsey":HIGH
+use-implicit-booleaness-not-comparison:34:3:34:19::"""empty_list == []"" can be simplified to ""not empty_list"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:37:3:37:19::"""empty_dict == {}"" can be simplified to ""not empty_dict"", if it is strictly a sequence, as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:42:11:42:18:bad_tuple_return:"""t == ()"" can be simplified to ""not t"", if it is strictly a sequence, as an empty tuple is falsey":HIGH
+use-implicit-booleaness-not-comparison:46:11:46:18:bad_list_return:"""b == []"" can be simplified to ""not b"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:50:11:50:18:bad_dict_return:"""c == {}"" can be simplified to ""not c"", if it is strictly a sequence, as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:52:7:52:24::"""empty_tuple == ()"" can be simplified to ""not empty_tuple"", if it is strictly a sequence, as an empty tuple is falsey":HIGH
+use-implicit-booleaness-not-comparison:53:7:53:23::"""empty_list == []"" can be simplified to ""not empty_list"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:54:7:54:23::"""empty_dict != {}"" can be simplified to ""empty_dict"", if it is strictly a sequence, as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:55:7:55:23::"""empty_tuple < ()"" can be simplified to ""not empty_tuple"", if it is strictly a sequence, as an empty tuple is falsey":HIGH
+use-implicit-booleaness-not-comparison:56:7:56:23::"""empty_list <= []"" can be simplified to ""not empty_list"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:57:7:57:23::"""empty_tuple > ()"" can be simplified to ""not empty_tuple"", if it is strictly a sequence, as an empty tuple is falsey":HIGH
+use-implicit-booleaness-not-comparison:58:7:58:23::"""empty_list >= []"" can be simplified to ""not empty_list"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:83:3:83:10::"""a == []"" can be simplified to ""not a"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:95:3:95:10::"""e == []"" can be simplified to ""not e"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:95:15:95:22::"""f == {}"" can be simplified to ""not f"", if it is strictly a sequence, as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:133:3:133:14::"""A.lst == []"" can be simplified to ""not A.lst"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:137:3:137:14::"""A.lst == []"" can be simplified to ""not A.lst"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:141:3:141:20::"""A.test(...) == []"" can be simplified to ""not A.test(...)"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:149:3:149:24::"""test_function(...) == []"" can be simplified to ""not test_function(...)"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:156:3:156:20::"""numpy_array == []"" can be simplified to ""not numpy_array"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:158:3:158:20::"""numpy_array != []"" can be simplified to ""numpy_array"", if it is strictly a sequence, as an empty list is falsey":HIGH
+use-implicit-booleaness-not-comparison:160:3:160:20::"""numpy_array >= ()"" can be simplified to ""not numpy_array"", if it is strictly a sequence, as an empty tuple is falsey":HIGH
+use-implicit-booleaness-not-comparison:185:3:185:13::"""data == {}"" can be simplified to ""not data"", if it is strictly a sequence, as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:187:3:187:13::"""data != {}"" can be simplified to ""data"", if it is strictly a sequence, as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:195:3:195:26::"""long_test == {}"" can be simplified to ""not long_test"", if it is strictly a sequence, as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:233:11:233:41:test_func:"""my_class.parent_function == {}"" can be simplified to ""not my_class.parent_function"", if it is strictly a sequence, as an empty dict is falsey":HIGH
+use-implicit-booleaness-not-comparison:234:11:234:37:test_func:"""my_class.my_property == {}"" can be simplified to ""not my_class.my_property"", if it is strictly a sequence, as an empty dict is falsey":HIGH

tests/functional/u/use/use_implicit_booleaness_not_comparison_to_string.txt

@@ -1,6 +1,6 @@
-use-implicit-booleaness-not-comparison-to-string:6:3:6:10::"""X is ''"" can be simplified to ""not X"" as an empty string is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-string:9:3:9:14::"""Y is not ''"" can be simplified to ""Y"" as an empty string is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-string:12:3:12:10::"""X == ''"" can be simplified to ""not X"" as an empty string is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-string:15:3:15:10::"""Y != ''"" can be simplified to ""Y"" as an empty string is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-string:18:3:18:10::"""'' == Y"" can be simplified to ""not Y"" as an empty string is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-string:21:3:21:10::"""'' != X"" can be simplified to ""X"" as an empty string is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-string:6:3:6:10::"""X is ''"" can be simplified to ""not X"", if it is striclty a string, as an empty string is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-string:9:3:9:14::"""Y is not ''"" can be simplified to ""Y"", if it is striclty a string, as an empty string is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-string:12:3:12:10::"""X == ''"" can be simplified to ""not X"", if it is striclty a string, as an empty string is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-string:15:3:15:10::"""Y != ''"" can be simplified to ""Y"", if it is striclty a string, as an empty string is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-string:18:3:18:10::"""'' == Y"" can be simplified to ""not Y"", if it is striclty a string, as an empty string is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-string:21:3:21:10::"""'' != X"" can be simplified to ""X"", if it is striclty a string, as an empty string is falsey":HIGH

tests/functional/u/use/use_implicit_booleaness_not_comparison_to_zero.txt

@@ -1,6 +1,6 @@
-use-implicit-booleaness-not-comparison-to-zero:6:3:6:9::"""X is 0"" can be simplified to ""not X"" as 0 is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-zero:12:3:12:13::"""Y is not 0"" can be simplified to ""Y"" as 0 is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-zero:18:3:18:9::"""X == 0"" can be simplified to ""not X"" as 0 is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-zero:24:3:24:9::"""0 == Y"" can be simplified to ""not Y"" as 0 is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-zero:27:3:27:9::"""Y != 0"" can be simplified to ""Y"" as 0 is falsey":HIGH
-use-implicit-booleaness-not-comparison-to-zero:30:3:30:9::"""0 != X"" can be simplified to ""X"" as 0 is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-zero:6:3:6:9::"""X is 0"" can be simplified to ""not X"", if it is strictly an int, as 0 is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-zero:12:3:12:13::"""Y is not 0"" can be simplified to ""Y"", if it is strictly an int, as 0 is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-zero:18:3:18:9::"""X == 0"" can be simplified to ""not X"", if it is strictly an int, as 0 is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-zero:24:3:24:9::"""0 == Y"" can be simplified to ""not Y"", if it is strictly an int, as 0 is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-zero:27:3:27:9::"""Y != 0"" can be simplified to ""Y"", if it is strictly an int, as 0 is falsey":HIGH
+use-implicit-booleaness-not-comparison-to-zero:30:3:30:9::"""0 != X"" can be simplified to ""X"", if it is strictly an int, as 0 is falsey":HIGH