Preserve order of configs and splits when using Parquet exports

src/datasets/utils/metadata.py

@@ -179,26 +179,37 @@ def _from_exported_parquet_files_and_dataset_infos(
         exported_parquet_files: List[Dict[str, Any]],
         dataset_infos: DatasetInfosDict,
     ) -> "MetadataConfigs":
-        return cls(
-            {
+        metadata_configs = {
+            config_name: {
+                "data_files": [
+                    {
+                        "split": split_name,
+                        "path": [
+                            parquet_file["url"].replace("refs%2Fconvert%2Fparquet", revision)
+                            for parquet_file in parquet_files_for_split
+                        ],
+                    }
+                    for split_name, parquet_files_for_split in groupby(parquet_files_for_config, itemgetter("split"))
+                ],
+                "version": str(dataset_infos.get(config_name, DatasetInfo()).version or "0.0.0"),
+            }
+            for config_name, parquet_files_for_config in groupby(exported_parquet_files, itemgetter("config"))
+        }
+        if dataset_infos:
+            # Preserve order of configs and splits
+            metadata_configs = {
                 config_name: {
                     "data_files": [
-                        {
-                            "split": split_name,
-                            "path": [
-                                parquet_file["url"].replace("refs%2Fconvert%2Fparquet", revision)
-                                for parquet_file in parquet_files_for_split
-                            ],
-                        }
-                        for split_name, parquet_files_for_split in groupby(
-                            parquet_files_for_config, itemgetter("split")
-                        )
+                        data_file
+                        for split_name in dataset_info.splits
+                        for data_file in metadata_configs[config_name]["data_files"]
+                        if data_file["split"] == split_name
                     ],
-                    "version": str(dataset_infos.get(config_name, DatasetInfo()).version or "0.0.0"),
+                    "version": metadata_configs[config_name]["version"],
                 }
-                for config_name, parquet_files_for_config in groupby(exported_parquet_files, itemgetter("config"))
+                for config_name, dataset_info in dataset_infos.items()
             }
-        )
+        return cls(metadata_configs)
 
     @classmethod
     def from_dataset_card_data(cls, dataset_card_data: DatasetCardData) -> "MetadataConfigs":

tests/test_metadata_util.py

@@ -9,6 +9,7 @@
 from huggingface_hub import DatasetCard, DatasetCardData
 
 from datasets.config import METADATA_CONFIGS_FIELD
+from datasets.info import DatasetInfo
 from datasets.utils.metadata import MetadataConfigs
 
 
@@ -249,3 +250,85 @@ def test_metadata_configs_incorrect_yaml():
         dataset_card_data = DatasetCard.load(path).data
         with pytest.raises(ValueError):
             _ = MetadataConfigs.from_dataset_card_data(dataset_card_data)
+
+
+def test_split_order_in_metadata_configs_from_exported_parquet_files_and_dataset_infos():
+    exported_parquet_files = [
+        {
+            "dataset": "beans",
+            "config": "default",
+            "split": "test",
+            "url": "https://huggingface.co/datasets/beans/resolve/refs%2Fconvert%2Fparquet/default/test/0000.parquet",
+            "filename": "0000.parquet",
+            "size": 17707203,
+        },
+        {
+            "dataset": "beans",
+            "config": "default",
+            "split": "train",
+            "url": "https://huggingface.co/datasets/beans/resolve/refs%2Fconvert%2Fparquet/default/train/0000.parquet",
+            "filename": "0000.parquet",
+            "size": 143780164,
+        },
+        {
+            "dataset": "beans",
+            "config": "default",
+            "split": "validation",
+            "url": "https://huggingface.co/datasets/beans/resolve/refs%2Fconvert%2Fparquet/default/validation/0000.parquet",
+            "filename": "0000.parquet",
+            "size": 18500862,
+        },
+    ]
+    dataset_infos = {
+        "default": DatasetInfo(
+            dataset_name="beans",
+            config_name="default",
+            version="0.0.0",
+            splits={
+                "train": {
+                    "name": "train",
+                    "num_bytes": 143996486,
+                    "num_examples": 1034,
+                    "shard_lengths": None,
+                    "dataset_name": "beans",
+                },
+                "validation": {
+                    "name": "validation",
+                    "num_bytes": 18525985,
+                    "num_examples": 133,
+                    "shard_lengths": None,
+                    "dataset_name": "beans",
+                },
+                "test": {
+                    "name": "test",
+                    "num_bytes": 17730506,
+                    "num_examples": 128,
+                    "shard_lengths": None,
+                    "dataset_name": "beans",
+                },
+            },
+            download_checksums={
+                "https://huggingface.co/datasets/beans/resolve/main/data/train.zip": {
+                    "num_bytes": 143812152,
+                    "checksum": None,
+                },
+                "https://huggingface.co/datasets/beans/resolve/main/data/validation.zip": {
+                    "num_bytes": 18504213,
+                    "checksum": None,
+                },
+                "https://huggingface.co/datasets/beans/resolve/main/data/test.zip": {
+                    "num_bytes": 17708541,
+                    "checksum": None,
+                },
+            },
+            download_size=180024906,
+            post_processing_size=None,
+            dataset_size=180252977,
+            size_in_bytes=360277883,
+        )
+    }
+    metadata_configs = MetadataConfigs._from_exported_parquet_files_and_dataset_infos(
+        "123", exported_parquet_files, dataset_infos
+    )
+    split_names = [data_file["split"] for data_file in metadata_configs["default"]["data_files"]]
+    assert split_names == ["train", "validation", "test"]