replace_captions.py

import json
from pathlib import Path

CAPTIONS_DIR = Path("/nobackup/zy_zhang/data/r1lite-20260423-lerobot/captions")
NEW_CAPTION = "coffee making"

files = sorted(CAPTIONS_DIR.glob("*.json"))
print(f"Found {len(files)} json files")

total_replaced = 0
for fp in files:
    with fp.open("r", encoding="utf-8") as f:
        data = json.load(f)

    replaced = 0
    for entry in data:
        if "caption" in entry and (entry["caption"] is None or entry["caption"] == "None"):
            entry["caption"] = NEW_CAPTION
            replaced += 1

    if replaced:
        with fp.open("w", encoding="utf-8") as f:
            json.dump(data, f, indent=2, ensure_ascii=False)
        total_replaced += replaced
    print(f"{fp.name}: replaced {replaced} captions")

print(f"\nDone. Total captions replaced: {total_replaced}")