Remove HfFileSystem and deprecate S3FileSystem (#6052)

* Remove `HfFileSystem` and deprecate `S3FileSystem`

* Update docstring

Author: mariosasko

src/datasets/arrow_dataset.py

@@ -1383,8 +1383,7 @@ def save_to_disk(
         storage_options: Optional[dict] = None,
     ):
         """
-        Saves a dataset to a dataset directory, or in a filesystem using either `s3fs.S3FileSystem` or
-        any implementation of `fsspec.spec.AbstractFileSystem`.
+        Saves a dataset to a dataset directory, or in a filesystem using any implementation of `fsspec.spec.AbstractFileSystem`.
 
         For [`Image`] and [`Audio`] data:
 
@@ -1601,8 +1600,7 @@ def load_from_disk(
     ) -> "Dataset":
         """
         Loads a dataset that was previously saved using [`save_to_disk`] from a dataset directory, or from a
-        filesystem using either `s3fs.S3FileSystem` or any implementation of
-        `fsspec.spec.AbstractFileSystem`.
+        filesystem using any implementation of `fsspec.spec.AbstractFileSystem`.
 
         Args:
             dataset_path (`str`):

src/datasets/dataset_dict.py

@@ -1199,8 +1199,7 @@ def save_to_disk(
         storage_options: Optional[dict] = None,
     ):
         """
-        Saves a dataset dict to a filesystem using either [`~filesystems.S3FileSystem`] or
-        `fsspec.spec.AbstractFileSystem`.
+        Saves a dataset dict to a filesystem using `fsspec.spec.AbstractFileSystem`.
 
         For [`Image`] and [`Audio`] data:
 
@@ -1293,8 +1292,7 @@ def load_from_disk(
         storage_options: Optional[dict] = None,
     ) -> "DatasetDict":
         """
-        Load a dataset that was previously saved using [`save_to_disk`] from a filesystem using either
-        [`~filesystems.S3FileSystem`] or `fsspec.spec.AbstractFileSystem`.
+        Load a dataset that was previously saved using [`save_to_disk`] from a filesystem using `fsspec.spec.AbstractFileSystem`.
 
         Args:
             dataset_dict_path (`str`):

src/datasets/filesystems/hffilesystem.py

@@ -1,6 +1,9 @@
 import s3fs
 
+from ..utils.deprecation_utils import deprecated
 
+
+@deprecated("Use s3fs.S3FileSystem instead.")
 class S3FileSystem(s3fs.S3FileSystem):
     """
     `datasets.filesystems.S3FileSystem` is a subclass of [`s3fs.S3FileSystem`](https://s3fs.readthedocs.io/en/latest/api.html).

src/datasets/filesystems/s3filesystem.py

@@ -2158,8 +2158,7 @@ def load_from_disk(
 ) -> Union[Dataset, DatasetDict]:
     """
     Loads a dataset that was previously saved using [`~Dataset.save_to_disk`] from a dataset directory, or
-    from a filesystem using either [`~datasets.filesystems.S3FileSystem`] or any implementation of
-    `fsspec.spec.AbstractFileSystem`.
+    from a filesystem using any implementation of `fsspec.spec.AbstractFileSystem`.
 
     Args:
         dataset_path (`str`):