self-assigning-variable skips class level assignments.

Close #2930

ChangeLog

@@ -10,6 +10,10 @@ Release date: TBA
 
 * ``ignored-modules`` can skip submodules. Close #3135
 
+* ``self-assigning-variable`` skips class level assignments.
+
+   Close #2930
+
 
 What's New in Pylint 2.4.1?
 ===========================

pylint/checkers/base.py

@@ -1495,6 +1495,10 @@ def visit_with(self, node):
 
     def _check_self_assigning_variable(self, node):
         # Detect assigning to the same variable.
+
+        scope = node.scope()
+        scope_locals = scope.locals
+
         rhs_names = []
         targets = node.targets
         if isinstance(targets[0], astroid.Tuple):
@@ -1518,6 +1522,10 @@ def _check_self_assigning_variable(self, node):
                 continue
             if not isinstance(target, astroid.AssignName):
                 continue
+            if isinstance(scope, astroid.ClassDef) and target.name in scope_locals:
+                # Check that the scope is different than a class level, which is usually
+                # a pattern to expose module level attributes as class level ones.
+                continue
             if target.name == lhs_name.name:
                 self.add_message(
                     "self-assigning-variable", args=(target.name,), node=target

tests/functional/s/self_assigning_variable.py

@@ -18,3 +18,10 @@ class Class:
 FIRST = Class()
 FIRST = FIRST # [self-assigning-variable]
 FIRST, SECOND = FIRST, CLS.FIRST # [self-assigning-variable]
+
+
+FOO = 1
+
+
+class RedefinedModuleLevel:
+    FOO = FOO