Fix export_tfhub module with BertV2.

PiperOrigin-RevId: 431236080

official/nlp/tools/export_tfhub_lib.py

@@ -84,13 +84,13 @@ def _create_model(
   """Creates the model to export and the model to restore the checkpoint.
 
   Args:
-    bert_config: A legacy `BertConfig` to create a `BertEncoder` object.
-      Exactly one of encoder_config and bert_config must be set.
+    bert_config: A legacy `BertConfig` to create a `BertEncoder` object. Exactly
+      one of encoder_config and bert_config must be set.
     encoder_config: An `EncoderConfig` to create an encoder of the configured
       type (`BertEncoder` or other).
-    with_mlm: A bool to control the second component of the result.
-      If True, will create a `BertPretrainerV2` object; otherwise, will
-      create a `BertEncoder` object.
+    with_mlm: A bool to control the second component of the result. If True,
+      will create a `BertPretrainerV2` object; otherwise, will create a
+      `BertEncoder` object.
 
   Returns:
     A Tuple of (1) a Keras model that will be exported, (2) a `BertPretrainerV2`
@@ -110,7 +110,11 @@ def _create_model(
 
   # Convert from list of named inputs to dict of inputs keyed by name.
   # Only the latter accepts a dict of inputs after restoring from SavedModel.
-  encoder_inputs_dict = {x.name: x for x in encoder.inputs}
+  if isinstance(encoder.inputs, list) or isinstance(encoder.inputs, tuple):
+    encoder_inputs_dict = {x.name: x for x in encoder.inputs}
+  else:
+    # encoder.inputs by default is dict for BertEncoderV2.
+    encoder_inputs_dict = encoder.inputs
   encoder_output_dict = encoder(encoder_inputs_dict)
   # For interchangeability with other text representations,
   # add "default" as an alias for BERT's whole-input reptesentations.
@@ -206,26 +210,28 @@ def export_model(export_path: Text,
     encoder_config: An optional `encoders.EncoderConfig` object.
     model_checkpoint_path: The path to the checkpoint.
     with_mlm: Whether to export the additional mlm sub-object.
-    copy_pooler_dense_to_encoder: Whether to copy the pooler's dense layer
-      used in the next sentence prediction task to the encoder.
+    copy_pooler_dense_to_encoder: Whether to copy the pooler's dense layer used
+      in the next sentence prediction task to the encoder.
     vocab_file: The path to the wordpiece vocab file, or None.
-    sp_model_file: The path to the sentencepiece model file, or None.
-      Exactly one of vocab_file and sp_model_file must be set.
+    sp_model_file: The path to the sentencepiece model file, or None. Exactly
+      one of vocab_file and sp_model_file must be set.
     do_lower_case: Whether to lower-case text before tokenization.
   """
   if with_mlm:
-    core_model, pretrainer = _create_model(bert_config=bert_config,
-                                           encoder_config=encoder_config,
-                                           with_mlm=with_mlm)
+    core_model, pretrainer = _create_model(
+        bert_config=bert_config,
+        encoder_config=encoder_config,
+        with_mlm=with_mlm)
     encoder = pretrainer.encoder_network
     # It supports both the new pretrainer checkpoint produced by TF-NLP and
     # the checkpoint converted from TF1 (original BERT, SmallBERTs).
     checkpoint_items = pretrainer.checkpoint_items
     checkpoint = tf.train.Checkpoint(**checkpoint_items)
   else:
-    core_model, encoder = _create_model(bert_config=bert_config,
-                                        encoder_config=encoder_config,
-                                        with_mlm=with_mlm)
+    core_model, encoder = _create_model(
+        bert_config=bert_config,
+        encoder_config=encoder_config,
+        with_mlm=with_mlm)
     checkpoint = tf.train.Checkpoint(
         model=encoder,  # Legacy checkpoints.
         encoder=encoder)
@@ -279,21 +285,26 @@ class BertPackInputsSavedModelWrapper(tf.train.Checkpoint):
     # overridable. Having this dynamically determined default argument
     # requires self.__call__ to be defined in this indirect way.
     default_seq_length = bert_pack_inputs.seq_length
+
     @tf.function(autograph=False)
     def call(inputs, seq_length=default_seq_length):
       return layers.BertPackInputs.bert_pack_inputs(
-          inputs, seq_length=seq_length,
+          inputs,
+          seq_length=seq_length,
           start_of_sequence_id=bert_pack_inputs.start_of_sequence_id,
           end_of_segment_id=bert_pack_inputs.end_of_segment_id,
           padding_id=bert_pack_inputs.padding_id)
+
     self.__call__ = call
 
     for ragged_rank in range(1, 3):
       for num_segments in range(1, 3):
-        _ = self.__call__.get_concrete_function(
-            [tf.RaggedTensorSpec([None] * (ragged_rank + 1), dtype=tf.int32)
-             for _ in range(num_segments)],
-            seq_length=tf.TensorSpec([], tf.int32))
+        _ = self.__call__.get_concrete_function([
+            tf.RaggedTensorSpec([None] * (ragged_rank + 1), dtype=tf.int32)
+            for _ in range(num_segments)
+        ],
+                                                seq_length=tf.TensorSpec(
+                                                    [], tf.int32))
 
 
 def create_preprocessing(*,
@@ -311,14 +322,14 @@ def create_preprocessing(*,
 
   Args:
     vocab_file: The path to the wordpiece vocab file, or None.
-    sp_model_file: The path to the sentencepiece model file, or None.
-      Exactly one of vocab_file and sp_model_file must be set.
-      This determines the type of tokenzer that is used.
+    sp_model_file: The path to the sentencepiece model file, or None. Exactly
+      one of vocab_file and sp_model_file must be set. This determines the type
+      of tokenzer that is used.
     do_lower_case: Whether to do lower case.
     tokenize_with_offsets: Whether to include the .tokenize_with_offsets
       subobject.
-    default_seq_length: The sequence length of preprocessing results from
-      root callable. This is also the default sequence length for the
+    default_seq_length: The sequence length of preprocessing results from root
+      callable. This is also the default sequence length for the
       bert_pack_inputs subobject.
 
   Returns:
@@ -378,7 +389,8 @@ def create_preprocessing(*,
 
 def _move_to_tmpdir(file_path: Optional[Text], tmpdir: Text) -> Optional[Text]:
   """Returns new path with same basename and hash of original path."""
-  if file_path is None: return None
+  if file_path is None:
+    return None
   olddir, filename = os.path.split(file_path)
   hasher = hashlib.sha1()
   hasher.update(olddir.encode("utf-8"))
@@ -460,12 +472,17 @@ def _check_no_assert(saved_model_path):
 
   assert_nodes = []
   graph_def = saved_model.meta_graphs[0].graph_def
-  assert_nodes += ["node '{}' in global graph".format(n.name)
-                   for n in graph_def.node if n.op == "Assert"]
+  assert_nodes += [
+      "node '{}' in global graph".format(n.name)
+      for n in graph_def.node
+      if n.op == "Assert"
+  ]
   for fdef in graph_def.library.function:
     assert_nodes += [
         "node '{}' in function '{}'".format(n.name, fdef.signature.name)
-        for n in fdef.node_def if n.op == "Assert"]
+        for n in fdef.node_def
+        if n.op == "Assert"
+    ]
   if assert_nodes:
     raise AssertionError(
         "Internal tool error: "