fixed PY-11293 namedtuple underscore-methods are not protected

python/src/com/jetbrains/python/inspections/PyProtectedMemberInspection.java

@@ -25,6 +25,7 @@ import com.jetbrains.python.PyBundle;
 import com.jetbrains.python.PyNames;
 import com.jetbrains.python.codeInsight.controlflow.ScopeOwner;
 import com.jetbrains.python.codeInsight.dataflow.scope.ScopeUtil;
+import com.jetbrains.python.codeInsight.stdlib.PyNamedTupleType;
 import com.jetbrains.python.psi.PyClass;
 import com.jetbrains.python.psi.PyExpression;
 import com.jetbrains.python.psi.PyReferenceExpression;
@@ -72,6 +73,7 @@ public class PyProtectedMemberInspection extends PyInspection {
     public void visitPyReferenceExpression(PyReferenceExpression node) {
       final PyExpression qualifier = node.getQualifier();
       if (qualifier == null || PyNames.CANONICAL_SELF.equals(qualifier.getText())) return;
+      if (myTypeEvalContext.getType(qualifier) instanceof PyNamedTupleType) return;
       final String name = node.getName();
       if (name != null && name.startsWith("_") && !name.startsWith("__") && !name.endsWith("__")) {
         final PyClass parentClass = getClassOwner(node);

python/testData/inspections/PyProtectedMemberInspection/namedTuple.py

@@ -0,0 +1,6 @@
+from collections import namedtuple
+
+i = namedtuple('Point', ['x', 'y'], verbose=True)
+i._replace( **{"a":"a"})
+
+

python/testSrc/com/jetbrains/python/inspections/PyProtectedMemberInspectionTest.java

@@ -50,6 +50,10 @@ public class PyProtectedMemberInspectionTest extends PyTestCase {
     doTest();
   }
 
+  public void testNamedTuple() {
+    doTest();
+  }
+
   public void testModule() {
     myFixture.configureByFiles(getTestName(true) + ".py", "tmp.py");
     myFixture.enableInspections(PyProtectedMemberInspection.class);