Allow Autograph tuple unpacking in for loops.

PiperOrigin-RevId: 209988449

2 files changed, 11 insertions, 1 deletions

diff --git a/tensorflow/contrib/autograph/converters/control_flow.py b/tensorflow/contrib/autograph/converters/control_flow.py
index f7dd3183b0..8d314250a0 100644
--- a/tensorflow/contrib/autograph/converters/control_flow.py
+++ b/tensorflow/contrib/autograph/converters/control_flow.py
@@ -310,7 +310,9 @@ class ControlFlowTransformer(converter.Base):
     template = """
       def extra_test_name(state_ssf):
         return extra_test_expr
-      def body_name(iterate, state_ssf):
+      def body_name(loop_vars, state_ssf):
+        # Workaround for PEP-3113
+        iterate = loop_vars
         body
         return state_ssf,
       state_ast_tuple = ag__.for_stmt(
diff --git a/tensorflow/contrib/autograph/converters/control_flow_test.py b/tensorflow/contrib/autograph/converters/control_flow_test.py
index 02bc00dbc8..2a6f3cb395 100644
--- a/tensorflow/contrib/autograph/converters/control_flow_test.py
+++ b/tensorflow/contrib/autograph/converters/control_flow_test.py
@@ -217,5 +217,13 @@ class ControlFlowTest(converter_testing.TestCase):
     with self.assertRaises(transformer.AutographParseError):
       control_flow.transform(node, ctx)
 
+  def test_for_tuple_unpacking(self):
+    def test_fn(x_list):
+      z = tf.constant(0)  # pylint:disable=undefined-variable
+      for i, x in enumerate(x_list):
+        z = z + x + i
+      return z
+
+    self.assertTransformedResult(test_fn, [3, 3], 7)
 if __name__ == '__main__':
   test.main()