Patch token classification pipeline (#8364)

* Patch token classification pipeline

* Some added tests for TokenClassificationArgumentHandler (#8366)
Co-authored-by: Nicolas Patry <patry.nicolas@protonmail.com>

src/transformers/pipelines.py

@@ -1333,18 +1333,17 @@ class TokenClassificationArgumentHandler(ArgumentHandler):
     def __call__(self, *args, **kwargs):
 
         if args is not None and len(args) > 0:
-            if isinstance(args, str):
-                inputs = [args]
-            else:
-                inputs = args
+            inputs = list(args)
             batch_size = len(inputs)
+        else:
+            raise ValueError("At least one input is required.")
 
-        offset_mapping = kwargs.get("offset_mapping", None)
+        offset_mapping = kwargs.get("offset_mapping")
         if offset_mapping:
             if isinstance(offset_mapping, list) and isinstance(offset_mapping[0], tuple):
                 offset_mapping = [offset_mapping]
             if len(offset_mapping) != batch_size:
-                raise ("offset_mapping should have the same batch size as the input")
+                raise ValueError("offset_mapping should have the same batch size as the input")
         return inputs, offset_mapping
 
 
@@ -1379,20 +1378,19 @@ class TokenClassificationPipeline(Pipeline):
         tokenizer: PreTrainedTokenizer,
         modelcard: Optional[ModelCard] = None,
         framework: Optional[str] = None,
-        args_parser: ArgumentHandler = None,
+        args_parser: ArgumentHandler = TokenClassificationArgumentHandler(),
         device: int = -1,
         binary_output: bool = False,
         ignore_labels=["O"],
         task: str = "",
         grouped_entities: bool = False,
-        ignore_subwords: bool = True,
+        ignore_subwords: bool = False,
     ):
         super().__init__(
             model=model,
             tokenizer=tokenizer,
             modelcard=modelcard,
             framework=framework,
-            args_parser=TokenClassificationArgumentHandler(),
             device=device,
             binary_output=binary_output,
             task=task,
@@ -1405,10 +1403,17 @@ class TokenClassificationPipeline(Pipeline):
         )
 
         self._basic_tokenizer = BasicTokenizer(do_lower_case=False)
+        self._args_parser = args_parser
         self.ignore_labels = ignore_labels
         self.grouped_entities = grouped_entities
         self.ignore_subwords = ignore_subwords
 
+        if self.ignore_subwords and not self.tokenizer.is_fast:
+            raise ValueError(
+                "Slow tokenizers cannot ignore subwords. Please set the `ignore_subwords` option"
+                "to `False` or use a fast tokenizer."
+            )
+
     def __call__(self, inputs: Union[str, List[str]], **kwargs):
         """
         Classify each token of the text(s) given as inputs.
@@ -1429,10 +1434,7 @@ class TokenClassificationPipeline(Pipeline):
               corresponding token in the sentence.
         """
 
-        if isinstance(inputs, str):
-            inputs = [inputs]
-
-        offset_mappings = kwargs.get("offset_mappings")
+        inputs, offset_mappings = self._args_parser(inputs, **kwargs)
 
         answers = []
 
@@ -1450,14 +1452,13 @@ class TokenClassificationPipeline(Pipeline):
                     return_offsets_mapping=self.tokenizer.is_fast,
                 )
                 if self.tokenizer.is_fast:
-                    offset_mapping = tokens["offset_mapping"].cpu().numpy()[0]
-                    del tokens["offset_mapping"]
+                    offset_mapping = tokens.pop("offset_mapping").cpu().numpy()[0]
                 elif offset_mappings:
                     offset_mapping = offset_mappings[i]
                 else:
-                    raise Exception("To decode [UNK] tokens use a fast tokenizer or provide offset_mapping parameter")
-                special_tokens_mask = tokens["special_tokens_mask"].cpu().numpy()[0]
-                del tokens["special_tokens_mask"]
+                    offset_mapping = None
+
+                special_tokens_mask = tokens.pop("special_tokens_mask").cpu().numpy()[0]
 
                 # Forward
                 if self.framework == "tf":
@@ -1482,14 +1483,17 @@ class TokenClassificationPipeline(Pipeline):
             ]
 
             for idx, label_idx in filtered_labels_idx:
-                start_ind, end_ind = offset_mapping[idx]
-                word_ref = sentence[start_ind:end_ind]
-                word = self.tokenizer.convert_ids_to_tokens([int(input_ids[idx])])[0]
-                is_subword = len(word_ref) != len(word)
-
-                if int(input_ids[idx]) == self.tokenizer.unk_token_id:
-                    word = word_ref
-                    is_subword = False
+                if offset_mapping is not None:
+                    start_ind, end_ind = offset_mapping[idx]
+                    word_ref = sentence[start_ind:end_ind]
+                    word = self.tokenizer.convert_ids_to_tokens([int(input_ids[idx])])[0]
+                    is_subword = len(word_ref) != len(word)
+
+                    if int(input_ids[idx]) == self.tokenizer.unk_token_id:
+                        word = word_ref
+                        is_subword = False
+                else:
+                    word = self.tokenizer.convert_ids_to_tokens(int(input_ids[idx]))
 
                 entity = {
                     "word": word,

tests/test_pipelines_ner.py

 import unittest
 
 from transformers import AutoTokenizer, pipeline
-from transformers.pipelines import Pipeline
+from transformers.pipelines import Pipeline, TokenClassificationArgumentHandler
 from transformers.testing_utils import require_tf, require_torch
 
 from .test_pipelines_common import CustomInputPipelineCommonMixin
@@ -107,13 +107,9 @@ class NerPipelineTests(CustomInputPipelineCommonMixin, unittest.TestCase):
     def test_tf_only(self):
         model_name = "Narsil/small"  # This model only has a TensorFlow version
         # We test that if we don't specificy framework='tf', it gets detected automatically
-        tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
-        nlp = pipeline(task="ner", model=model_name, tokenizer=tokenizer)
+        nlp = pipeline(task="ner", model=model_name)
         self._test_pipeline(nlp)
 
-    #         offset=tokenizer(VALID_INPUTS[0],return_offsets_mapping=True)['offset_mapping']
-    #         pipeline_running_kwargs = {"offset_mapping"}  # Additional kwargs to run the pipeline with
-
     @require_tf
     def test_tf_defaults(self):
         for model_name in self.small_models:
@@ -122,9 +118,8 @@ class NerPipelineTests(CustomInputPipelineCommonMixin, unittest.TestCase):
         self._test_pipeline(nlp)
 
     @require_tf
-    def test_tf_small(self):
+    def test_tf_small_ignore_subwords_available_for_fast_tokenizers(self):
         for model_name in self.small_models:
-            print(model_name)
             tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
             nlp = pipeline(
                 task="ner",
@@ -136,27 +131,41 @@ class NerPipelineTests(CustomInputPipelineCommonMixin, unittest.TestCase):
             )
             self._test_pipeline(nlp)
 
-            for model_name in self.small_models:
-                tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
-                nlp = pipeline(
-                    task="ner",
-                    model=model_name,
-                    tokenizer=tokenizer,
-                    framework="tf",
-                    grouped_entities=True,
-                    ignore_subwords=False,
-                )
-                self._test_pipeline(nlp)
+        for model_name in self.small_models:
+            tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
+            nlp = pipeline(
+                task="ner",
+                model=model_name,
+                tokenizer=tokenizer,
+                framework="tf",
+                grouped_entities=True,
+                ignore_subwords=False,
+            )
+            self._test_pipeline(nlp)
 
     @require_torch
-    def test_pt_defaults(self):
+    def test_pt_ignore_subwords_slow_tokenizer_raises(self):
         for model_name in self.small_models:
-            tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
+            tokenizer = AutoTokenizer.from_pretrained(model_name)
+
+            with self.assertRaises(ValueError):
+                pipeline(task="ner", model=model_name, tokenizer=tokenizer, ignore_subwords=True)
+
+    @require_torch
+    def test_pt_defaults_slow_tokenizer(self):
+        for model_name in self.small_models:
+            tokenizer = AutoTokenizer.from_pretrained(model_name)
             nlp = pipeline(task="ner", model=model_name, tokenizer=tokenizer)
             self._test_pipeline(nlp)
 
     @require_torch
-    def test_torch_small(self):
+    def test_pt_defaults(self):
+        for model_name in self.small_models:
+            nlp = pipeline(task="ner", model=model_name)
+            self._test_pipeline(nlp)
+
+    @require_torch
+    def test_pt_small_ignore_subwords_available_for_fast_tokenizers(self):
         for model_name in self.small_models:
             tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
             nlp = pipeline(
@@ -170,3 +179,46 @@ class NerPipelineTests(CustomInputPipelineCommonMixin, unittest.TestCase):
                 task="ner", model=model_name, tokenizer=tokenizer, grouped_entities=True, ignore_subwords=False
             )
             self._test_pipeline(nlp)
+
+
+class TokenClassificationArgumentHandlerTestCase(unittest.TestCase):
+    def setUp(self):
+        self.args_parser = TokenClassificationArgumentHandler()
+
+    def test_simple(self):
+        string = "This is a simple input"
+
+        inputs, offset_mapping = self.args_parser(string)
+        self.assertEqual(inputs, [string])
+        self.assertEqual(offset_mapping, None)
+
+        inputs, offset_mapping = self.args_parser(string, string)
+        self.assertEqual(inputs, [string, string])
+        self.assertEqual(offset_mapping, None)
+
+        inputs, offset_mapping = self.args_parser(string, offset_mapping=[(0, 1), (1, 2)])
+        self.assertEqual(inputs, [string])
+        self.assertEqual(offset_mapping, [[(0, 1), (1, 2)]])
+
+        inputs, offset_mapping = self.args_parser(string, string, offset_mapping=[[(0, 1), (1, 2)], [(0, 2), (2, 3)]])
+        self.assertEqual(inputs, [string, string])
+        self.assertEqual(offset_mapping, [[(0, 1), (1, 2)], [(0, 2), (2, 3)]])
+
+    def test_errors(self):
+        string = "This is a simple input"
+
+        # 2 sentences, 1 offset_mapping
+        with self.assertRaises(ValueError):
+            self.args_parser(string, string, offset_mapping=[[(0, 1), (1, 2)]])
+
+        # 2 sentences, 1 offset_mapping
+        with self.assertRaises(ValueError):
+            self.args_parser(string, string, offset_mapping=[(0, 1), (1, 2)])
+
+        # 1 sentences, 2 offset_mapping
+        with self.assertRaises(ValueError):
+            self.args_parser(string, offset_mapping=[[(0, 1), (1, 2)], [(0, 2), (2, 3)]])
+
+        # 0 sentences, 1 offset_mapping
+        with self.assertRaises(ValueError):
+            self.args_parser(offset_mapping=[[(0, 1), (1, 2)]])