add dataset unpack script

scripts/unpack_dataset.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+"""
+Extract all tar archives under train/ and val/ directories.
+"""
+from __future__ import annotations
+
+import argparse
+import tarfile
+from pathlib import Path
+
+
+def iter_archives(root: Path) -> list[Path]:
+    patterns = ("*.tar", "*.tar.gz", "*.tgz")
+    archives: list[Path] = []
+    for pattern in patterns:
+        archives.extend(root.rglob(pattern))
+    return sorted(set(archives))
+
+
+def extract_archive(archive: Path, dest: Path, *, dry_run: bool) -> None:
+    if dry_run:
+        print(f"[dry-run] {archive} -> {dest}")
+        return
+    with tarfile.open(archive, "r:*") as tar:
+        tar.extractall(path=dest)
+    print(f"extracted {archive} -> {dest}")
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(
+        description="Extract tar archives under train/ and val/ directories."
+    )
+    parser.add_argument(
+        "--root",
+        type=Path,
+        default=Path("."),
+        help="Project root containing train/ and val/ (default: current directory).",
+    )
+    parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="List archives without extracting.",
+    )
+    args = parser.parse_args()
+
+    root = args.root.resolve()
+    targets = [root / "train", root / "val"]
+    archives: list[Path] = []
+    for target in targets:
+        if target.is_dir():
+            archives.extend(iter_archives(target))
+        else:
+            print(f"skip missing directory: {target}")
+
+    if not archives:
+        print("no archives found")
+        return 0
+
+    for archive in archives:
+        extract_archive(archive, archive.parent, dry_run=args.dry_run)
+
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())