GH-3098/add fewnerd corpus

.pre-commit-config.yaml

@@ -19,7 +19,7 @@ repos:
               tests/resources/.*\.(tsv|txt|testa|testb|train|conllu|json)
           )$
   - repo: https://github.com/pycqa/isort
-    rev: 5.10.1
+    rev: 5.12.0
     hooks:
       - id: isort
         name: isort (python)

flair/datasets/__init__.py

@@ -168,6 +168,7 @@
     CONLL_03_GERMAN,
     CONLL_03_SPANISH,
     CONLL_2000,
+    FEWNERD,
     KEYPHRASE_INSPEC,
     KEYPHRASE_SEMEVAL2010,
     KEYPHRASE_SEMEVAL2017,
@@ -438,6 +439,7 @@
     "CONLL_03_GERMAN",
     "CONLL_03_SPANISH",
     "CONLL_2000",
+    "FEWNERD",
     "KEYPHRASE_INSPEC",
     "KEYPHRASE_SEMEVAL2010",
     "KEYPHRASE_SEMEVAL2017",

flair/datasets/sequence_labeling.py

@@ -1092,6 +1092,79 @@ def __init__(
         )
 
 
+class FEWNERD(ColumnCorpus):
+    def __init__(
+        self,
+        setting: str = "supervised",
+        **corpusargs,
+    ):
+        assert setting in ["supervised", "inter", "intra"]
+
+        base_path = flair.cache_root / "datasets"
+        self.dataset_name = self.__class__.__name__.lower()
+        self.data_folder = base_path / self.dataset_name / setting
+        self.bio_format_data = base_path / self.dataset_name / setting / "bio_format"
+
+        if not self.data_folder.exists():
+            self._download(setting=setting)
+
+        if not self.bio_format_data.exists():
+            self._generate_splits(setting)
+
+        super(FEWNERD, self).__init__(
+            self.bio_format_data,
+            column_format={0: "text", 1: "ner"},
+            **corpusargs,
+        )
+
+    def _download(self, setting):
+        _URLs = {
+            "supervised": "https://cloud.tsinghua.edu.cn/f/09265750ae6340429827/?dl=1",
+            "intra": "https://cloud.tsinghua.edu.cn/f/a0d3efdebddd4412b07c/?dl=1",
+            "inter": "https://cloud.tsinghua.edu.cn/f/165693d5e68b43558f9b/?dl=1",
+        }
+
+        log.info(f"FewNERD ({setting}) dataset not found, downloading.")
+        dl_path = _URLs[setting]
+        dl_dir = cached_path(dl_path, Path("datasets") / self.dataset_name / setting)
+
+        if setting not in os.listdir(self.data_folder):
+            import zipfile
+
+            from tqdm import tqdm
+
+            log.info("FewNERD dataset has not been extracted yet, extracting it now. This might take a while.")
+            with zipfile.ZipFile(dl_dir, "r") as zip_ref:
+                for f in tqdm(zip_ref.namelist()):
+                    if f.endswith("/"):
+                        os.makedirs(self.data_folder / f)
+                    else:
+                        zip_ref.extract(f, path=self.data_folder)
+
+    def _generate_splits(self, setting):
+        log.info(
+            f"FewNERD splits for {setting} have not been parsed into BIO format, parsing it now. This might take a while."
+        )
+        os.mkdir(self.bio_format_data)
+        for split in os.listdir(self.data_folder / setting):
+            with open(self.data_folder / setting / split, "r") as source:
+                with open(self.bio_format_data / split, "w") as target:
+                    previous_tag = None
+                    for line in source:
+                        if line == "" or line == "\n":
+                            target.write("\n")
+                        else:
+                            token, tag = line.split("\t")
+                            tag = tag.replace("\n", "")
+                            if tag == "O":
+                                target.write(token + "\t" + tag + "\n")
+                            elif previous_tag != tag and tag != "O":
+                                target.write(token + "\t" + "B-" + tag + "\n")
+                            elif previous_tag == tag and tag != "O":
+                                target.write(token + "\t" + "I-" + tag + "\n")
+                            previous_tag = tag
+
+
 class BIOSCOPE(ColumnCorpus):
     def __init__(
         self,