sure hope this works

my_webdataset.py

@@ -0,0 +1,58 @@
+import datasets
+import tarfile
+from datasets import Features, Value
+from datasets.download.download_manager import DownloadManager
+from typing import List, NamedTuple, TypedDict, Generator
+from PIL import Image
+
+Example = TypedDict('Example', {
+  'index': int,
+  'tar': str,
+  'tar_path': str,
+  'img': Image.Image,
+})
+
+class KeyedExample(NamedTuple):
+    key: int
+    example: Example
+
+tar_count = 2
+files = [f'./{ix:05d}.tar' for ix in range(tar_count)]
+
+class MyWebdataset(datasets.GeneratorBasedBuilder):
+    VERSION = '1.0.0'
+    
+    def _info(self) -> datasets.DatasetInfo:
+        print(__file__)
+        return datasets.DatasetInfo(
+            description="My webdataset",
+            features=Features({
+                'index': Value('uint32'),
+                'tar': Value('string'),
+                'tar_path': Value('string'),
+                'img': datasets.Image(),
+            }),
+        )
+    
+    def _split_generators(self, dl_manager: DownloadManager) -> List[datasets.SplitGenerator]:
+        return [
+            datasets.SplitGenerator(
+                name=datasets.Split.TRAIN,
+                gen_kwargs={"filepaths": dl_manager.download(files)},
+            )
+        ]
+
+    def _generate_examples(self, filepaths: List[str]) -> Generator[KeyedExample, None, None]:
+        index = 0
+        for filepath in filepaths:
+            with tarfile.open(filepath, "r:") as tar:
+                for member in tar.getmembers():
+                    with tar.extractfile(member.name) as f:
+                        pil: Image.Image = Image.open(f)
+                        yield KeyedExample(index, Example(
+                            index=index,
+                            tar=filepath,
+                            tar_path=member.path,
+                            img=pil,
+                        ))
+                        index += 1