replace subdirecty_mapping by split_paths and allow list of files for values

brat.py

@@ -2,7 +2,7 @@ import glob
 import logging
 from dataclasses import dataclass
 from os import listdir, path
-from typing import Dict, List, Optional
+from typing import Dict, List, Optional, Union
 
 import datasets
 from datasets import BuilderConfig, DatasetInfo, Features, Sequence, SplitGenerator, Value
@@ -18,8 +18,9 @@ class BratConfig(BuilderConfig):
     description: Optional[str] = None
     citation: Optional[str] = None
     homepage: Optional[str] = None
-
-    subdirectory_mapping: Optional[Dict[str, str]] = None
+    
+    # paths to directories or files per split (relative to url or data_dir)
+    split_paths: Optional[Dict[str, Union[str, List[str]]]] = None
     file_name_blacklist: Optional[List[str]] = None
     ann_file_extension: str = "ann"
     txt_file_extension: str = "txt"
@@ -270,14 +271,15 @@ class Brat(datasets.GeneratorBasedBuilder):
                     )
         return res
 
-    def _generate_examples(self, files=None, directory=None):
+    def _generate_examples(self, base_dir: str, files: Optional[List[str]] = None, directory: Optional[str] = None):
         """Read context (.txt) and annotation (.ann) files."""
         if files is None:
-            assert (
-                directory is not None
-            ), "If files is None, directory has to be provided, but it is also None."
+            if directory is None:
+                raise ValueError("Either files or directory has to be provided.")
             _files = glob.glob(f"{directory}/*.{self.config.ann_file_extension}")
             files = sorted(path.splitext(fn)[0] for fn in _files)
+        elif directory is not None:
+            raise ValueError("Only one of files or directory can be provided.")
 
         for filename in files:
             basename = path.basename(filename)
@@ -311,24 +313,36 @@ class Brat(datasets.GeneratorBasedBuilder):
 
             data_dir = dl_manager.download_and_extract(self.config.url)
 
-        subdirectory_mapping = self.config.subdirectory_mapping
         # if no subdirectory mapping is provided, ...
-        if subdirectory_mapping is None:
+        if self.config.split_paths is None:
             # ... use available subdirectories as split names ...
             subdirs = [f for f in listdir(data_dir) if path.isdir(path.join(data_dir, f))]
             if len(subdirs) > 0:
-                subdirectory_mapping = {subdir: subdir for subdir in subdirs}
+                split_paths = {subdir: {"directory": subdir} for subdir in subdirs}
             else:
                 # ... otherwise, default to a single train split with the base directory
-                subdirectory_mapping = {"": "train"}
+                split_paths = {"train": {"directory": ""}}
+        else:
+            split_paths = {}
+            for split, paths in self.config.split_paths.items():
+                if isinstance(paths, str):
+                    split_paths[split] = {"directory": paths}
+                elif isinstance(paths, list):
+                    split_paths[split] = {"files": paths}
+                else:
+                    raise ValueError(
+                        f"split_paths must be a dict containing either a single path to a directory "
+                        f"or a list of file paths, but found: {paths}"
+                    )
 
         return [
             SplitGenerator(
                 name=split,
                 # These kwargs will be passed to _generate_examples
                 gen_kwargs={
-                    "directory": path.join(data_dir, subdir),
+                    "base_dir": data_dir,
+                    **split_kwargs,
                 },
             )
-            for subdir, split in subdirectory_mapping.items()
-        ]
+            for split, split_kwargs in split_paths.items()
+        ]