example: add dataset structure validation helper

python-sdk/nuscenes/scripts/validate_dataset_structure.py

@@ -0,0 +1,104 @@
+"""
+Validate the local structure of a nuScenes dataset directory.
+
+This script checks whether the expected metadata files for a nuScenes version
+exist under the provided dataroot. It is intended as a lightweight helper for
+users who want to verify that the dataset was extracted into the expected
+folder layout before using the devkit.
+
+Example usage:
+
+    python python-sdk/nuscenes/scripts/validate_dataset_structure.py \
+        --dataroot /data/sets/nuscenes \
+        --version v1.0-mini
+"""
+
+import argparse
+from pathlib import Path
+from typing import List
+
+
+REQUIRED_METADATA_FILES: List[str] = [
+    "attribute.json",
+    "calibrated_sensor.json",
+    "category.json",
+    "ego_pose.json",
+    "instance.json",
+    "log.json",
+    "map.json",
+    "sample.json",
+    "sample_annotation.json",
+    "sample_data.json",
+    "scene.json",
+    "sensor.json",
+    "visibility.json",
+]
+
+
+def validate_dataset_structure(dataroot: str, version: str) -> None:
+    """
+    Validate that required nuScenes metadata files exist.
+
+    :param dataroot: Path to the nuScenes dataset root.
+    :param version: Dataset version, for example 'v1.0-mini'.
+    """
+    root = Path(dataroot).expanduser().resolve()
+    version_dir = root / version
+
+    print(f"Checking nuScenes dataset structure")
+    print(f"Dataroot: {root}")
+    print(f"Version: {version}")
+    print(f"Expected metadata directory: {version_dir}")
+
+    if not root.exists():
+        raise FileNotFoundError(f"Dataroot does not exist: {root}")
+
+    if not version_dir.exists():
+        raise FileNotFoundError(
+            f"Version directory does not exist: {version_dir}\n"
+            f"Expected layout example: {root}/{version}/sample.json"
+        )
+
+    missing_files = [
+        filename for filename in REQUIRED_METADATA_FILES
+        if not (version_dir / filename).exists()
+    ]
+
+    if missing_files:
+        print("\nMissing metadata files:")
+        for filename in missing_files:
+            print(f"  - {version_dir / filename}")
+
+        raise FileNotFoundError(
+            "\nDataset structure validation failed. "
+            "Check that the dataset archive was fully extracted and that the "
+            "version folder is not nested one level too deep."
+        )
+
+    print("\nAll required metadata files were found.")
+    print("Dataset structure looks valid.")
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        description="Validate the local structure of a nuScenes dataset directory."
+    )
+
+    parser.add_argument(
+        "--dataroot",
+        default="/data/sets/nuscenes",
+        help="Path to the nuScenes dataset root.",
+    )
+
+    parser.add_argument(
+        "--version",
+        default="v1.0-mini",
+        help="nuScenes dataset version to validate.",
+    )
+
+    return parser.parse_args()
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    validate_dataset_structure(dataroot=args.dataroot, version=args.version)