scripts/card_stats.py

"""Emit JSON statistics for the train parquet, for use by the dataset-card skill."""
from __future__ import annotations

import json
import sys
from pathlib import Path

import pyarrow.parquet as pq

REPO = Path(__file__).resolve().parent.parent
PARQUET = REPO / "data" / "train-00000-of-00001.parquet"


def main() -> int:
    if not PARQUET.exists():
        print(json.dumps({"error": f"missing {PARQUET}"}))
        return 1
    pf = pq.ParquetFile(PARQUET)
    table = pf.read()
    num_rows = table.num_rows
    num_bytes_disk = PARQUET.stat().st_size
    num_bytes_uncompressed = sum(chunk.nbytes for c in table.columns for chunk in c.chunks)
    out = {
        "num_rows": num_rows,
        "num_bytes_disk": num_bytes_disk,
        "num_bytes_uncompressed": int(num_bytes_uncompressed),
        "schema": [{"name": f.name, "type": str(f.type)} for f in table.schema],
        "parquet_relpath": "data/train-00000-of-00001.parquet",
    }
    print(json.dumps(out, ensure_ascii=False, indent=2))
    return 0


if __name__ == "__main__":
    sys.exit(main())