Fix Lambda layer deserialization polluting core module.

PiperOrigin-RevId: 314978364
Change-Id: Iae42839140cdb0853f91c77a3a1c7ff16d391e02

tensorflow/python/keras/layers/core.py

@@ -1025,7 +1025,7 @@ class Lambda(Layer):
   def _parse_function_from_config(
       cls, config, custom_objects, func_attr_name, module_attr_name,
       func_type_attr_name):
-    globs = globals()
+    globs = globals().copy()
     module = config.pop(module_attr_name, None)
     if module in sys.modules:
       globs.update(sys.modules[module].__dict__)

tensorflow/python/keras/layers/core_test.py

@@ -29,6 +29,7 @@ from tensorflow.python.framework import ops
 from tensorflow.python.framework import tensor_spec
 from tensorflow.python.keras import keras_parameterized
 from tensorflow.python.keras import testing_utils
+from tensorflow.python.keras.layers import core
 from tensorflow.python.keras.mixed_precision.experimental import policy
 from tensorflow.python.ops import array_ops
 from tensorflow.python.ops import math_ops
@@ -274,6 +275,12 @@ class LambdaLayerTest(keras_parameterized.TestCase):
     expected_out = ragged_factory_ops.constant([[2.0], [3.0, 4.0]])
     self.assertAllClose(out, expected_out)
 
+  def test_lambda_deserialization_does_not_pollute_core(self):
+    layer = keras.layers.Lambda(lambda x: x + 1)
+    config = layer.get_config()
+    keras.layers.Lambda.from_config(config)
+    self.assertNotIn(self.__class__.__name__, dir(core))
+
 
 class TestStatefulLambda(keras_parameterized.TestCase):