| """Download and extract CaScenes from the Hugging Face Hub. |
| |
| Usage: |
| python download.py --out ./workspace |
| python download.py --out ./workspace --split test # download only test |
| python download.py --out ./workspace --no-extract # download tarballs only |
| |
| Requirements: |
| pip install -U huggingface_hub |
| """ |
|
|
| import argparse |
| import hashlib |
| import subprocess |
| import sys |
| from pathlib import Path |
|
|
| from huggingface_hub import HfApi, hf_hub_download |
|
|
| REPO_ID = "Zixia3/CaScenes" |
| REPO_TYPE = "dataset" |
| SPLITS = ("train", "test") |
|
|
|
|
| def sha256_of(path: Path, chunk: int = 1 << 20) -> str: |
| h = hashlib.sha256() |
| with path.open("rb") as f: |
| for buf in iter(lambda: f.read(chunk), b""): |
| h.update(buf) |
| return h.hexdigest() |
|
|
|
|
| def load_expected_sums(sumfile: Path) -> dict[str, str]: |
| sums: dict[str, str] = {} |
| for line in sumfile.read_text().splitlines(): |
| line = line.strip() |
| if not line or line.startswith("#"): |
| continue |
| digest, _, name = line.partition(" ") |
| sums[name.strip()] = digest.strip() |
| return sums |
|
|
|
|
| def verify(path: Path, expected: str) -> None: |
| print(f" verifying {path.name} ...", flush=True) |
| got = sha256_of(path) |
| if got != expected: |
| raise SystemExit( |
| f"sha256 mismatch for {path.name}:\n expected {expected}\n got {got}" |
| ) |
| print(f" {path.name}: OK") |
|
|
|
|
| def list_split_files(split: str) -> list[str]: |
| """Return remote filenames belonging to a split, sorted in concat order.""" |
| api = HfApi() |
| files = api.list_repo_files(REPO_ID, repo_type=REPO_TYPE) |
| if split == "train": |
| |
| parts = sorted(f for f in files if f.startswith("train.tar.part-")) |
| if parts: |
| return parts |
| |
| if "train.tar" in files: |
| return ["train.tar"] |
| raise SystemExit("no train.tar.part-* or train.tar found in repo") |
| if split == "test": |
| if "test.tar" in files: |
| return ["test.tar"] |
| raise SystemExit("test.tar not found in repo") |
| raise ValueError(split) |
|
|
|
|
| def extract_split(split: str, local_files: list[Path], out_dir: Path) -> None: |
| out_dir.mkdir(parents=True, exist_ok=True) |
| print(f" extracting {split} ({len(local_files)} file(s)) -> {out_dir} ...", flush=True) |
| if len(local_files) == 1: |
| rc = subprocess.call(["tar", "-xf", str(local_files[0]), "-C", str(out_dir)]) |
| if rc != 0: |
| raise SystemExit(f"tar -xf failed for {local_files[0].name}") |
| return |
| |
| cat = subprocess.Popen(["cat", *map(str, local_files)], stdout=subprocess.PIPE) |
| tar = subprocess.Popen(["tar", "-xf", "-", "-C", str(out_dir)], stdin=cat.stdout) |
| if cat.stdout is not None: |
| cat.stdout.close() |
| tar_rc = tar.wait() |
| cat.wait() |
| if cat.returncode != 0 or tar_rc != 0: |
| raise SystemExit(f"extraction failed (cat={cat.returncode}, tar={tar_rc})") |
|
|
|
|
| def main() -> None: |
| ap = argparse.ArgumentParser(description="Download & extract CaScenes") |
| ap.add_argument("--out", required=True, type=Path, help="workspace root; CaScenes/ will land inside") |
| ap.add_argument("--split", choices=SPLITS, action="append", |
| help="restrict to these splits (repeatable). Default: both.") |
| ap.add_argument("--cache", type=Path, default=None, |
| help="huggingface_hub cache dir (default: HF_HOME or ~/.cache/huggingface)") |
| ap.add_argument("--no-extract", action="store_true", help="download tarballs only, skip extraction") |
| args = ap.parse_args() |
|
|
| splits = tuple(args.split) if args.split else SPLITS |
| args.out.mkdir(parents=True, exist_ok=True) |
|
|
| sums_path = Path(hf_hub_download(REPO_ID, "SHA256SUMS", repo_type=REPO_TYPE, cache_dir=args.cache)) |
| expected = load_expected_sums(sums_path) |
|
|
| for split in splits: |
| remote_files = list_split_files(split) |
| local_files: list[Path] = [] |
| for rf in remote_files: |
| local = Path(hf_hub_download(REPO_ID, rf, repo_type=REPO_TYPE, cache_dir=args.cache)) |
| if rf in expected: |
| verify(local, expected[rf]) |
| else: |
| print(f"warning: {rf} not listed in SHA256SUMS; skipping verification", file=sys.stderr) |
| local_files.append(local) |
| if not args.no_extract: |
| extract_split(split, local_files, args.out) |
|
|
| print("done.") |
|
|
|
|
| if __name__ == "__main__": |
| main() |
|
|
