fix base_path

Author: lhoestq

src/datasets/builder.py

@@ -213,9 +213,12 @@ def create_config_id(
         else:
             return self.name
 
-    def _resolve_data_files(self, base_path: str, download_config: DownloadConfig) -> None:
+    def _resolve_data_files(self, base_path: Optional[str], download_config: DownloadConfig) -> None:
         if isinstance(self.data_files, DataFilesPatternsDict):
-            base_path = xjoin(base_path, self.data_dir) if self.data_dir else base_path
+            if base_path is None:
+                base_path = self.data_dir
+            else:
+                base_path = xjoin(base_path, self.data_dir) if self.data_dir else base_path
             self.data_files = self.data_files.resolve(base_path, download_config)
 
 

src/datasets/load.py

@@ -2240,7 +2240,7 @@ def load_dataset_builder(
     else:
         builder_config = None
     if builder_config and builder_config.data_files is not None:
-        builder_config._resolve_data_files(base_path=builder_kwargs["base_path"], download_config=download_config)
+        builder_config._resolve_data_files(base_path=builder_kwargs.get("base_path"), download_config=download_config)
         hash = update_hash_for_cache(hash, data_files=builder_config.data_files)
     # Instantiate the dataset builder
     builder_instance: DatasetBuilder = builder_cls(