Add loading script

liv4ever.py

@@ -0,0 +1,145 @@
+"""OPUS liv4ever dataset."""
+
+from pathlib import Path
+
+import datasets
+
+
+_DESCRIPTION = """\
+This is the Livonian 4-lingual parallel corpus. Livonian is a Uralic / Finnic language with just about 20 fluent
+speakers and no native speakers (as of 2021). The texts and translations in this corpus were collected from all the
+digital text resources that could be found by the authors; scanned and printed materials are left for future work.
+"""
+
+_HOMEPAGE = "https://opus.nlpl.eu/liv4ever.php"
+
+_LICENSE = "CC BY-SA"
+
+_CITATION = r"""
+@inproceedings{rikters-etal-2022-machine,
+    title = "Machine Translation for {L}ivonian: Catering to 20 Speakers",
+    author = "Rikters, Mat{\=\i}ss  and
+      Tomingas, Marili  and
+      Tuisk, Tuuli  and
+      Ern{\v{s}}treits, Valts  and
+      Fishel, Mark",
+    booktitle = "Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)",
+    month = may,
+    year = "2022",
+    address = "Dublin, Ireland",
+    publisher = "Association for Computational Linguistics",
+    url = "https://aclanthology.org/2022.acl-short.55",
+    doi = "10.18653/v1/2022.acl-short.55",
+    pages = "508--514",
+}
+@inproceedings{tiedemann-2012-parallel,
+    title = "Parallel Data, Tools and Interfaces in {OPUS}",
+    author = {Tiedemann, J{\"o}rg},
+    booktitle = "Proceedings of the Eighth International Conference on Language Resources and Evaluation ({LREC}'12)",
+    month = may,
+    year = "2012",
+    address = "Istanbul, Turkey",
+    publisher = "European Language Resources Association (ELRA)",
+    url = "http://www.lrec-conf.org/proceedings/lrec2012/pdf/463_Paper.pdf",
+    pages = "2214--2218",
+}
+"""
+
+_URLS = {
+    "parallel": "https://opus.nlpl.eu/download.php?f=liv4ever/v1/moses/{}-{}.txt.zip",
+    "monolingual": "https://opus.nlpl.eu/download.php?f=liv4ever/v1/mono/{}.txt.gz",
+}
+_LANGUAGES = ["en", "et", "fr", "liv", "lv"]
+_LANGUAGE_PAIRS = [("en", "liv"), ("et", "liv"), ("fr", "liv"), ("liv", "lv")]
+
+
+class Liv4EverConfig(datasets.BuilderConfig):
+    def __init__(self, language_pair=None, language=None, version=datasets.Version("1.0.0"), **kwargs):
+        if (language_pair and language) or (not language_pair and not language):
+            raise ValueError("Pass either 'language_pair' or 'language'")
+        if language_pair:
+            if isinstance(language_pair, str):
+                language_pair = language_pair.split("-")
+            language_pair = tuple(sorted(language_pair))
+            name = f"{'-'.join(language_pair) if language_pair else language}"
+        else:
+            name = f"{language}"
+        super().__init__(name=name, version=version, **kwargs)
+        self.language_pair = language_pair
+        self.language = language
+
+
+class Liv4Ever(datasets.GeneratorBasedBuilder):
+
+    BUILDER_CONFIG_CLASS = Liv4EverConfig
+
+    BUILDER_CONFIGS = [Liv4EverConfig(language_pair=language_pair) for language_pair in _LANGUAGE_PAIRS] + [
+        Liv4EverConfig(language=language) for language in _LANGUAGES
+    ]
+
+    def _info(self):
+        if self.config.language_pair:
+            features = datasets.Features(
+                {
+                    "translation": datasets.Translation(languages=self.config.language_pair),
+                }
+            )
+        else:
+            features = datasets.Features(
+                {
+                    "text": datasets.Value("string"),
+                }
+            )
+        return datasets.DatasetInfo(
+            description=_DESCRIPTION,
+            features=features,
+            homepage=_HOMEPAGE,
+            license=_LICENSE,
+            citation=_CITATION,
+        )
+
+    def _split_generators(self, dl_manager):
+        url = (
+            _URLS["parallel"].format(*self.config.language_pair)
+            if self.config.language_pair
+            else _URLS["monolingual"].format(self.config.language)
+        )
+        path = dl_manager.download_and_extract(url)
+        return [
+            datasets.SplitGenerator(
+                name=datasets.Split.TRAIN,
+                gen_kwargs={
+                    "path": path,
+                },
+            ),
+        ]
+
+    def _generate_examples(self, path):
+        if self.config.language_pair:
+            for key, item in enumerate(_parse_txt_pair(path, self.config.language_pair)):
+                # Skip first line containing just the language name
+                if key == 0:
+                    continue
+                yield key, {"translation": item}
+        else:
+            for key, line in enumerate(_parse_txt(path)):
+                # Skip first line containing just the language name
+                if key == 0:
+                    continue
+                yield key, {
+                    "text": line,
+                }
+
+
+def _parse_txt(path):
+    with open(path, encoding="utf-8") as f:
+        for line in f:
+            line = line.strip()
+            if line:
+                yield line
+
+
+def _parse_txt_pair(path, language_pair):
+    paths = [sorted(Path(path).glob(f"*.{language}"))[0] for language in language_pair]
+    for line_pair in zip(_parse_txt(paths[0]), _parse_txt(paths[1])):
+        yield {language: line for language, line in zip(language_pair, line_pair)}