Fix wrong type hints in data_files (#6910)

* Fix wrong type hints in data_files

* Add missing type hints in DataFilesList

* Inverse condition with negation

* Fix type hint of origin metadata

* Add missing arg to resolve_pattern docstring

* Minor fix docstrings

* Remove TypeAlias

Author: albertvillanova

src/datasets/data_files.py

@@ -22,6 +22,9 @@
 from .utils.py_utils import glob_pattern_to_regex, string_to_dict
 
 
+SingleOriginMetadata = Union[Tuple[str, str], Tuple[str], Tuple[()]]
+
+
 SANITIZED_DEFAULT_SPLIT = str(Split.TRAIN)
 
 
@@ -361,6 +364,7 @@ def resolve_pattern(
         base_path (str): Base path to use when resolving relative paths.
         allowed_extensions (Optional[list], optional): White-list of file extensions to use. Defaults to None (all extensions).
             For example: allowed_extensions=[".csv", ".json", ".txt", ".parquet"]
+        download_config ([`DownloadConfig`], *optional*): Specific download configuration parameters.
     Returns:
         List[str]: List of paths or URLs to the local or remote files that match the patterns.
     """
@@ -516,17 +520,17 @@ def get_metadata_patterns(
 def _get_single_origin_metadata(
     data_file: str,
     download_config: Optional[DownloadConfig] = None,
-) -> Tuple[str]:
+) -> SingleOriginMetadata:
     data_file, storage_options = _prepare_path_and_storage_options(data_file, download_config=download_config)
     fs, *_ = url_to_fs(data_file, **storage_options)
     if isinstance(fs, HfFileSystem):
         resolved_path = fs.resolve_path(data_file)
-        return (resolved_path.repo_id, resolved_path.revision)
+        return resolved_path.repo_id, resolved_path.revision
     elif isinstance(fs, HTTPFileSystem) and data_file.startswith(config.HF_ENDPOINT):
         hffs = HfFileSystem(endpoint=config.HF_ENDPOINT, token=download_config.token)
         data_file = "hf://" + data_file[len(config.HF_ENDPOINT) + 1 :].replace("/resolve/", "@", 1)
         resolved_path = hffs.resolve_path(data_file)
-        return (resolved_path.repo_id, resolved_path.revision)
+        return resolved_path.repo_id, resolved_path.revision
     info = fs.info(data_file)
     # s3fs uses "ETag", gcsfs uses "etag", and for local we simply check mtime
     for key in ["ETag", "etag", "mtime"]:
@@ -539,7 +543,7 @@ def _get_origin_metadata(
     data_files: List[str],
     download_config: Optional[DownloadConfig] = None,
     max_workers: Optional[int] = None,
-) -> Tuple[str]:
+) -> List[SingleOriginMetadata]:
     max_workers = max_workers if max_workers is not None else config.HF_DATASETS_MULTITHREADING_MAX_WORKERS
     return thread_map(
         partial(_get_single_origin_metadata, download_config=download_config),
@@ -555,11 +559,11 @@ def _get_origin_metadata(
 class DataFilesList(List[str]):
     """
     List of data files (absolute local paths or URLs).
-    It has two construction methods given the user's data files patterns :
+    It has two construction methods given the user's data files patterns:
     - ``from_hf_repo``: resolve patterns inside a dataset repository
     - ``from_local_or_remote``: resolve patterns from a local path
 
-    Moreover DataFilesList has an additional attribute ``origin_metadata``.
+    Moreover, DataFilesList has an additional attribute ``origin_metadata``.
     It can store:
     - the last modified time of local files
     - ETag of remote files
@@ -570,11 +574,11 @@ class DataFilesList(List[str]):
     This is useful for caching Dataset objects that are obtained from a list of data files.
     """
 
-    def __init__(self, data_files: List[str], origin_metadata: List[Tuple[str]]):
+    def __init__(self, data_files: List[str], origin_metadata: List[SingleOriginMetadata]) -> None:
         super().__init__(data_files)
         self.origin_metadata = origin_metadata
 
-    def __add__(self, other):
+    def __add__(self, other: "DataFilesList") -> "DataFilesList":
         return DataFilesList([*self, *other], self.origin_metadata + other.origin_metadata)
 
     @classmethod
@@ -646,9 +650,9 @@ class DataFilesDict(Dict[str, DataFilesList]):
     - ``from_hf_repo``: resolve patterns inside a dataset repository
     - ``from_local_or_remote``: resolve patterns from a local path
 
-    Moreover each list is a DataFilesList. It is possible to hash the dictionary
+    Moreover, each list is a DataFilesList. It is possible to hash the dictionary
     and get a different hash if and only if at least one file changed.
-    For more info, see ``DataFilesList``.
+    For more info, see [`DataFilesList`].
 
     This is useful for caching Dataset objects that are obtained from a list of data files.
 
@@ -666,14 +670,14 @@ def from_local_or_remote(
         out = cls()
         for key, patterns_for_key in patterns.items():
             out[key] = (
-                DataFilesList.from_local_or_remote(
+                patterns_for_key
+                if isinstance(patterns_for_key, DataFilesList)
+                else DataFilesList.from_local_or_remote(
                     patterns_for_key,
                     base_path=base_path,
                     allowed_extensions=allowed_extensions,
                     download_config=download_config,
                 )
-                if not isinstance(patterns_for_key, DataFilesList)
-                else patterns_for_key
             )
         return out
 
@@ -689,15 +693,15 @@ def from_hf_repo(
         out = cls()
         for key, patterns_for_key in patterns.items():
             out[key] = (
-                DataFilesList.from_hf_repo(
+                patterns_for_key
+                if isinstance(patterns_for_key, DataFilesList)
+                else DataFilesList.from_hf_repo(
                     patterns_for_key,
                     dataset_info=dataset_info,
                     base_path=base_path,
                     allowed_extensions=allowed_extensions,
                     download_config=download_config,
                 )
-                if not isinstance(patterns_for_key, DataFilesList)
-                else patterns_for_key
             )
         return out
 
@@ -712,14 +716,14 @@ def from_patterns(
         out = cls()
         for key, patterns_for_key in patterns.items():
             out[key] = (
-                DataFilesList.from_patterns(
+                patterns_for_key
+                if isinstance(patterns_for_key, DataFilesList)
+                else DataFilesList.from_patterns(
                     patterns_for_key,
                     base_path=base_path,
                     allowed_extensions=allowed_extensions,
                     download_config=download_config,
                 )
-                if not isinstance(patterns_for_key, DataFilesList)
-                else patterns_for_key
             )
         return out
 
@@ -751,7 +755,7 @@ def __add__(self, other):
     @classmethod
     def from_patterns(
         cls, patterns: List[str], allowed_extensions: Optional[List[str]] = None
-    ) -> "DataFilesPatternsDict":
+    ) -> "DataFilesPatternsList":
         return cls(patterns, [allowed_extensions] * len(patterns))
 
     def resolve(
@@ -777,7 +781,7 @@ def resolve(
         origin_metadata = _get_origin_metadata(data_files, download_config=download_config)
         return DataFilesList(data_files, origin_metadata)
 
-    def filter_extensions(self, extensions: List[str]) -> "DataFilesList":
+    def filter_extensions(self, extensions: List[str]) -> "DataFilesPatternsList":
         return DataFilesPatternsList(
             self, [allowed_extensions + extensions for allowed_extensions in self.allowed_extensions]
         )
@@ -795,12 +799,12 @@ def from_patterns(
         out = cls()
         for key, patterns_for_key in patterns.items():
             out[key] = (
-                DataFilesPatternsList.from_patterns(
+                patterns_for_key
+                if isinstance(patterns_for_key, DataFilesPatternsList)
+                else DataFilesPatternsList.from_patterns(
                     patterns_for_key,
                     allowed_extensions=allowed_extensions,
                 )
-                if not isinstance(patterns_for_key, DataFilesPatternsList)
-                else patterns_for_key
             )
         return out