Fix DuplicatedKeysError

Fix DuplicatedKeysError, by using a unique key for each example.

ESCI-product-dataset.py

@@ -71,8 +71,10 @@ class ESCIproduct(datasets.GeneratorBasedBuilder):
 
     def _generate_examples(self, files):
         """Yields examples."""
+        key = 0
         for filepath in files:
             with open(filepath, encoding="utf-8") as f:
                 for line in f:
                     data = json.loads(line)
-                    yield data['query_id'], data
+                    yield key, data
+                    key += 1