Add loading script

wikititles.py

@@ -0,0 +1,41 @@
+import datasets
+
+from .wmt_utils import Wmt, WmtConfig
+
+
+_URL = "http://www.statmt.org/wmt22/translation-task.html"
+# TODO: Update with citation of overview paper once it is published.
+_CITATION = """
+@ONLINE {wmt22translate,
+    author = {Wikimedia Foundation},
+    title  = {EMNLP 2022 Seventh Conference on Machine Translation (WMT22), Shared Task: General Machine Translation},
+    url    = {http://www.statmt.org/wmt22/translation-task.html}
+}
+"""
+
+
+_LANGUAGE_PAIRS = (
+    {(src, "en") for src in ["cs", "de", "ha", "ig", "is", "ja", "ps", "ru", "zh"]}
+    | {("ca", "es"), ("de", "fr"), ("bn", "hi")}
+    | {(src, "pt") for src in ["ca", "es"]}
+    | {(src, "ro") for src in ["ca", "es", "pt"]}
+    | {("xh", "zu")}
+)
+
+
+class Wikititles(Wmt):
+
+    BUILDER_CONFIGS = [
+        WmtConfig(
+            description="Wikititles v3 {0}-{1} translation dataset".format(*language_pair),
+            url=_URL,
+            citation=_CITATION,
+            language_pair=language_pair,
+            version=datasets.Version("3.0.0"),
+        )
+        for language_pair in _LANGUAGE_PAIRS
+    ]
+
+    @property
+    def _subsets(self):
+        return {datasets.Split.TRAIN: ["wikititles_v3"]}