[python] Support custom dataset readers in PaimonLeRobotDataset

docs/docs/pypaimon/lerobot.md

@@ -226,3 +226,30 @@ Without `tag_name`, the latest snapshots are used. Frame lookups use the BTree
 on `index`; payloads remain lazy. Video decoding prefers TorchCodec, falls back
 to PyAV, and reuses a bounded decoder cache. Set `video_backend` to force
 either decoder.
+
+Subclass `PaimonDatasetReader` for a custom logical frame layout:
+
+```python
+from pypaimon.multimodal import PaimonDatasetReader, PaimonLeRobotDataset
+
+class CustomDatasetReader(PaimonDatasetReader):
+    def __init__(self, metadata, source, **kwargs):
+        self._source = source
+        super().__init__(
+            metadata,
+            file_io=getattr(source, "file_io", None),
+            **kwargs,
+        )
+
+    def read_indices(self, indices, columns):
+        return self._source.read_indices(indices, columns)
+
+reader = CustomDatasetReader(
+    metadata, source, delta_timestamps=delta_timestamps
+)
+dataset = PaimonLeRobotDataset(reader)
+```
+
+`source` exposes `read_indices` and optional `file_io`. Pass
+`schema=source.schema` for eager schema validation. `PaimonDatasetReader`
+reuses the standard Episode, delta-window, media, and Torch handling.

paimon-python/pypaimon/multimodal/__init__.py

@@ -29,7 +29,10 @@
     Hdf5File,
     Hdf5LoadResult,
 )
-from pypaimon.multimodal.lerobot.dataset import PaimonLeRobotDataset
+from pypaimon.multimodal.lerobot.dataset import (
+    PaimonDatasetReader,
+    PaimonLeRobotDataset,
+)
 from pypaimon.multimodal.rosbag import (
     RosbagLoadResult,
     RosbagSource,
@@ -67,6 +70,7 @@
     "MultimodalTable",
     "NoSuchKey",
     "ObjectInfo",
+    "PaimonDatasetReader",
     "PaimonLeRobotDataset",
     "PutObjectResult",
     "RosbagLoadResult",

paimon-python/pypaimon/multimodal/lerobot/__init__.py

@@ -17,11 +17,15 @@
 """LeRobot Dataset v3 integration for multimodal Paimon tables."""
 
 from pypaimon.multimodal.lerobot.api import load_from_lerobot
-from pypaimon.multimodal.lerobot.dataset import PaimonLeRobotDataset
+from pypaimon.multimodal.lerobot.dataset import (
+    PaimonDatasetReader,
+    PaimonLeRobotDataset,
+)
 from pypaimon.multimodal.lerobot.writer import PaimonLeRobotWriter
 
 
 __all__ = [
+    "PaimonDatasetReader",
     "PaimonLeRobotDataset",
     "PaimonLeRobotWriter",
     "load_from_lerobot",