Update nemo_corpus.py

nemo_corpus.py

@@ -1,10 +1,7 @@
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
-
 import os
 import tempfile
 from pathlib import Path
-
+from typing import Iterable, Tuple, List
 import datasets
 
 logger = datasets.logging.get_logger(__name__)
@@ -31,6 +28,93 @@ _DESCRIPTION = """\
 URL = "https://github.com/OnlpLab/NEMO-Corpus"
 
 
+def tokens_with_tags_to_spans(tags: Iterable[str], tokens: Iterable[str]) -> List[
+    Tuple[str, int, int]]:
+    """
+    Convert a list of tokens and tags to a list of spans for BIOSE/BIOLU schemes tags.
+    Args:
+        tags: list of entities tags
+        tokens: list of tokens
+    Note that the end index returned by this function is exclusive.
+    No, need to increment the end by 1.
+    Returns:
+        list of {span, start, end, entity, start_char, end_char}
+        where span is a phrase/tokens, start and end are the indices of the span,
+        entity is the entity type, and start_char and end_char are the start
+        and end characters of the span.
+    """
+    entities = []
+    start = None
+    start_char = None
+    words = []
+    curr_pos = 0
+    for i, (tag, token) in enumerate(zip(tags, tokens)):
+        if tag is None or tag.startswith("-"):
+            if start is not None:
+                start = None
+                start_char = None
+                words = []
+            else:
+                end_pos = curr_pos + len(token)
+                words.append(token)
+                entities.append({
+                    "entity": "",
+                    "span": " ".join(words),
+                    "start": i,
+                    "end": i + 1,
+                    "start_char": curr_pos,
+                    "end_char": end_pos
+                })
+        elif tag.startswith("O"):
+            pass
+        elif tag.startswith("I"):
+            words.append(token)
+            if start is None:
+                raise ValueError(
+                    "Invalid BILUO tag sequence: Got a tag starting with {start} "
+                    "without a preceding 'B' (beginning of an entity). "
+                    "Tag sequence:\n{tags}".format(start="I", tags=list(tags)[: i + 1])
+                )
+        elif tag.startswith("U") or tag.startswith("S"):
+            end_pos = curr_pos + len(token)
+            entities.append({
+                "entity": tag[2:],
+                "span": token,
+                "start": i,
+                "end": i + 1,
+                "start_char": curr_pos,
+                "end_char": end_pos
+            })
+        elif tag.startswith("B"):
+            start = i
+            start_char = curr_pos
+            words.append(token)
+        elif tag.startswith("L") or tag.startswith("E"):
+            if start is None:
+                raise ValueError(
+                    "Invalid BILUO tag sequence: Got a tag starting with {start} "
+                    "without a preceding 'B' (beginning of an entity). "
+                    "Tag sequence:\n{tags}".format(start="L", tags=list(tags)[: i + 1])
+                )
+            end_pos = curr_pos + len(token)
+            words.append(token)
+            entities.append({
+                "entity": tag[2:],
+                "span": " ".join(words),
+                "start": start,
+                "end": i + 1,
+                "start_char": start_char,
+                "end_char": end_pos
+            })
+            start = None
+            start_char = None
+            words = []
+        else:
+            raise ValueError("Invalid BILUO tag: '{}'.".format(tag))
+        curr_pos += len(token) + len(" ")
+    return entities
+
+
 class NemoCorpusConfig(datasets.BuilderConfig):
     """BuilderConfig for NemoCorpus"""
 
@@ -48,6 +132,7 @@ class NemoCorpusConfig(datasets.BuilderConfig):
             {
                 "id": datasets.Value("string"),
                 "tokens": datasets.Sequence(datasets.Value("string")),
+                "sentence": datasets.Value("string"),
                 "ner_tags": datasets.Sequence(
                     datasets.features.ClassLabel(
                         names=['S-ANG', 'B-ANG', 'I-ANG', 'E-ANG',
@@ -62,6 +147,14 @@ class NemoCorpusConfig(datasets.BuilderConfig):
                                'B-WOA', 'E-WOA', 'I-WOA', 'S-WOA']
                     )
                 ),
+                "spans": datasets.Sequence({
+                    "span": datasets.Value("string"),
+                    "start": datasets.Value("int32"),
+                    "end": datasets.Value("int32"),
+                    "entity": datasets.Value("string"),
+                    "start_char": datasets.Value("int32"),
+                    "end_char": datasets.Value("int32"),
+                })
             }
         )
 
@@ -138,6 +231,7 @@ class NemoCorpus(datasets.GeneratorBasedBuilder):
             "validation": dl_manager.download(folder / "morph_gold_dev.bmes"),
             "test": dl_manager.download(folder / "morph_gold_test.bmes"),
         }
+
         return [
             datasets.SplitGenerator(name=datasets.Split.TRAIN,
                                     gen_kwargs={"filepath": data_files["train"]}),
@@ -164,8 +258,10 @@ class NemoCorpus(datasets.GeneratorBasedBuilder):
                     if tokens:
                         yield guid, {
                             "id": str(guid),
+                            "sentence": " ".join(tokens),
                             "tokens": tokens,
                             "ner_tags": ner_tags,
+                            "spans": tokens_with_tags_to_spans(ner_tags, tokens)
                         }
                         guid += 1
                         tokens = []
@@ -177,8 +273,10 @@ class NemoCorpus(datasets.GeneratorBasedBuilder):
             # last example
             yield guid, {
                 "id": str(guid),
+                "sentence": " ".join(tokens),
                 "tokens": tokens,
                 "ner_tags": ner_tags,
+                "spans": tokens_with_tags_to_spans(ner_tags, tokens)
             }
 
     def _generate_examples_nested(self, filepath, sep=" "):