PY-38928 Parentheses around unpacking for "for" loop target variables break type inference

GitOrigin-RevId: 9debb720880dd77b47c325e426e2d76c74135192

python/python-psi-impl/src/com/jetbrains/python/psi/impl/PyTargetExpressionImpl.java

@@ -301,8 +301,9 @@ public class PyTargetExpressionImpl extends PyBaseElementImpl<PyTargetExpression
     if (source != null) {
       final PyType sourceType = context.getType(source);
       final PyType type = getIterationType(sourceType, source, this, context);
-      if (type instanceof PyTupleType && target instanceof PyTupleExpression) {
-        return PyTypeChecker.getTargetTypeFromTupleAssignment(this, (PyTupleExpression)target, (PyTupleType)type);
+      target = PyPsiUtils.flattenParens(target);
+      if (type instanceof PyTupleType tupleType && target instanceof PyTupleExpression tupleExpression) {
+        return PyTypeChecker.getTargetTypeFromTupleAssignment(this, tupleExpression, tupleType);
       }
       if (target == this && type != null) {
         return type;

python/testSrc/com/jetbrains/python/PyTypeTest.java

@@ -1114,6 +1114,17 @@ public class PyTypeTest extends PyTestCase {
            "(a, (_, expr)) = (1, xs) ");
   }
 
+  // PY-38928
+  public void testIterateListOfTuples() {
+    doTest(
+      "str",
+      """
+        for ((_, expr)) in [(1, 'foo')]:
+            pass
+        """
+    );
+  }
+
   public void testConstructorUnification() {
     doTest("C[int]",
            """