Closes #1327

tests/test_visitors/test_ast/test_subscripts/test_slice_assignment.py

@@ -18,7 +18,7 @@
     ':',
     'slice(1)',
     'slice()',
-    'slice(1,3)',
+    'slice(1, 3)',
 ])
 def test_slice_assignment(
     assert_errors,

wemake_python_styleguide/logic/naming/name_nodes.py

@@ -66,8 +66,8 @@ def get_variables_from_node(node: ast.AST) -> List[str]:
     Can be used with any nodes that operate with ``ast.Name`` or ``ast.Tuple``
     as targets for the assignment.
 
-    Can be used with nodes like ``ast.Assign``, ``ast.Tuple``, ``ast.For``,
-    ``ast.With``, etc.
+    Can be used with nodes like
+    ``ast.Assign``, ``ast.Tuple``, ``ast.For``, ``ast.With``, etc.
     """
     names: List[str] = []
     naive_attempt = extract_name(node)

wemake_python_styleguide/logic/tree/classes.py

@@ -51,6 +51,7 @@ def is_forbidden_super_class(class_name: Optional[str]) -> bool:
 
 def get_attributes(
     node: ast.ClassDef,
+    *,
     include_annotated: bool,
 ) -> _AllAttributes:
     """
@@ -102,7 +103,7 @@ def _get_class_attribute(
     subnode: ast.AST,
 ) -> Optional[AnyAssign]:
     return subnode if (
-        nodes.get_context(subnode) == node and
+        nodes.get_context(subnode) is node and
         getattr(subnode, 'value', None) and
         isinstance(subnode, AssignNodes)
     ) else None
@@ -113,7 +114,7 @@ def _get_annotated_class_attribute(
     subnode: ast.AST,
 ) -> Optional[AnyAssign]:
     return subnode if (
-        nodes.get_context(subnode) == node and
+        nodes.get_context(subnode) is node and
         (
             getattr(subnode, 'value', None) and
             isinstance(subnode, AssignNodes)
@@ -124,7 +125,7 @@ def _get_annotated_class_attribute(
 def find_getters_and_setters(node: ast.ClassDef) -> Iterable[AnyFunctionDef]:
     """Returns nodes of all getter or setter methods."""
     for sub in ast.walk(node):
-        is_correct_context = nodes.get_context(sub) == node
+        is_correct_context = nodes.get_context(sub) is node
         if isinstance(sub, FunctionNodes) and is_correct_context:
             if sub.name[:GETTER_LENGTH] in _GetterSetterPrefixes:
                 yield sub

wemake_python_styleguide/logic/tree/variables.py

@@ -1,6 +1,9 @@
 import ast
 from typing import Union
 
+from wemake_python_styleguide.logic import nodes
+from wemake_python_styleguide.types import AnyVariableDef
+
 _VarDefinition = Union[ast.AST, ast.expr]
 _LocalVariable = Union[ast.Name, ast.ExceptHandler]
 
@@ -12,6 +15,18 @@ def get_variable_name(node: _LocalVariable) -> str:
     return getattr(node, 'name', '')
 
 
+def looks_like_builtin(node: AnyVariableDef) -> bool:
+    """
+    We allow attributes and class-level builtin overrides.
+
+    Like: ``self.map = {}`` or ``def map(self, function):``
+    """
+    return (
+        not isinstance(node, ast.Attribute) and
+        not isinstance(nodes.get_context(node), ast.ClassDef)
+    )
+
+
 def is_valid_block_variable_definition(node: _VarDefinition) -> bool:
     """Is used to check either block variables are correctly defined."""
     if isinstance(node, ast.Tuple):

wemake_python_styleguide/presets/topics/naming.py

@@ -0,0 +1,13 @@
+from typing_extensions import Final
+
+from wemake_python_styleguide.visitors.ast.naming import validation, variables
+
+#: Used to store all naming related visitors to be later passed to checker:
+PRESET: Final = (
+    validation.WrongNameVisitor,
+
+    variables.WrongModuleMetadataVisitor,
+    variables.WrongVariableAssignmentVisitor,
+    variables.UnusedVariableUsageVisitor,
+    variables.UnusedVariableDefinitionVisitor,
+)

wemake_python_styleguide/presets/types/tree.py

@@ -1,6 +1,6 @@
 from typing_extensions import Final
 
-from wemake_python_styleguide.presets.topics import complexity
+from wemake_python_styleguide.presets.topics import complexity, naming
 from wemake_python_styleguide.visitors.ast import (  # noqa: WPS235
     annotations,
     attributes,
@@ -16,7 +16,6 @@
     keywords,
     loops,
     modules,
-    naming,
     operators,
     statements,
     subscripts,
@@ -62,12 +61,6 @@
 
     imports.WrongImportVisitor,
 
-    naming.WrongNameVisitor,
-    naming.WrongModuleMetadataVisitor,
-    naming.WrongVariableAssignmentVisitor,
-    naming.UnusedVariableUsageVisitor,
-    naming.UnusedVariableDefinitionVisitor,
-
     builtins.WrongNumberVisitor,
     builtins.WrongStringVisitor,
     builtins.WrongFormatStringVisitor,
@@ -114,6 +107,7 @@
     subscripts.ImplicitDictGetVisitor,
     subscripts.CorrectKeyVisitor,
 
-    # Complexity:
+    # Topics:
     *complexity.PRESET,
+    *naming.PRESET,
 )

wemake_python_styleguide/types.py

@@ -61,6 +61,9 @@
 #: In case we need to work with any loop: sync, async, and while.
 AnyLoop = Union[AnyFor, ast.While]
 
+#: This is how you can define a variable in Python.
+AnyVariableDef = Union[ast.Name, ast.Attribute, ast.ExceptHandler]
+
 #: All different comprehension types in one place.
 AnyComprehension = Union[
     ast.ListComp,
@@ -72,19 +75,9 @@
 #: In cases we need to work with both sync and async context managers.
 AnyWith = Union[ast.With, ast.AsyncWith]
 
-#: Tuple of AST node types for declarative syntax.
-AnyNodes = Tuple[Type[ast.AST], ...]
-
 #: When we search for assign elements, we also need typed assign.
 AnyAssign = Union[ast.Assign, ast.AnnAssign]
 
-#: That's how we define context of operations.
-ContextNodes = Union[
-    ast.Module,
-    ast.ClassDef,
-    AnyFunctionDef,
-]
-
 #: In cases we need to work with both access types.
 AnyAccess = Union[
     ast.Attribute,
@@ -98,9 +91,19 @@
     ast.Call,
 ]
 
+#: Tuple of AST node types for declarative syntax.
+AnyNodes = Tuple[Type[ast.AST], ...]
+
 #: We use this type to work with any text-like values. Related to `AnyText`.
 AnyTextPrimitive = Union[str, bytes]
 
+#: That's how we define context of operations.
+ContextNodes = Union[
+    ast.Module,
+    ast.ClassDef,
+    AnyFunctionDef,
+]
+
 #: Flake8 API format to return error messages.
 CheckResult = Tuple[int, int, str, type]
 

wemake_python_styleguide/visitors/ast/classes.py

@@ -125,10 +125,10 @@ def _check_getters_setters_methods(self, node: ast.ClassDef) -> None:
         flat_class_attributes = name_nodes.flat_variable_names(class_attributes)
 
         attributes_stripped = {
-            class_attribute.lstrip('_')
+            class_attribute.lstrip(constants.UNUSED_PLACEHOLDER)
             for class_attribute in flat_class_attributes
         }.union({
-            instance.attr.lstrip('_')
+            instance.attr.lstrip(constants.UNUSED_PLACEHOLDER)
             for instance in instance_attributes
         })
 
@@ -409,7 +409,7 @@ def _check_method_order(self, node: ast.ClassDef) -> None:
 
         for subnode in ast.walk(node):
             if isinstance(subnode, FunctionNodes):
-                if nodes.get_context(subnode) == node:
+                if nodes.get_context(subnode) is node:
                     method_nodes.append(subnode.name)
 
         ideal = sorted(method_nodes, key=self._ideal_order, reverse=True)