#!/usr/bin/env python3 """ Script to extract files from blobs created for Hugging Face datasets. Usage: python blob_extract.py /path/to/blob/directory --file path/to/extract.txt --output /path/to/save """ import json import argparse from pathlib import Path import shutil import os class BlobExtractor: def __init__(self, blob_dir: str): """Initialize extractor with directory containing blobs and metadata.""" self.blob_dir = Path(blob_dir) self.metadata_path = self.blob_dir / 'metadata.json' self.metadata = self._load_metadata() def _load_metadata(self) -> dict: """Load and return the metadata JSON file.""" if not self.metadata_path.exists(): raise FileNotFoundError(f"Metadata file not found at {self.metadata_path}") with open(self.metadata_path, 'r') as f: return json.load(f) def list_files(self): """Print all files stored in the blobs.""" print("\nFiles available for extraction:") print("-" * 50) for file_path in sorted(self.metadata.keys()): info = self.metadata[file_path] print(f"{file_path:<50} (size: {info['size']} bytes, blob: {info['blob']})") def extract_file(self, file_path: str, output_path: str = None) -> None: """ Extract a specific file from the blob. Args: file_path: Path of the file within the blob output_path: Where to save the extracted file. If None, uses original filename """ if file_path not in self.metadata: print(f"Error: File '{file_path}' not found in blobs") return info = self.metadata[file_path] blob_path = self.blob_dir / info['blob'] # Determine output path if output_path is None: output_path = file_path # Create output directory if needed output_path = Path(output_path) output_path.parent.mkdir(parents=True, exist_ok=True) print(f"\nExtracting: {file_path}") print(f"From blob: {info['blob']}") print(f"Size: {info['size']} bytes") print(f"To: {output_path}") try: with open(blob_path, 'rb') as src, open(output_path, 'wb') as dst: # Seek to file's position in blob src.seek(info['offset']) # Copy exact number of bytes shutil.copyfileobj(src, dst, length=info['size']) print(f"Successfully extracted to: {output_path}") except Exception as e: print(f"Error extracting file: {e}") def main(): parser = argparse.ArgumentParser(description="Extract files from blobs") parser.add_argument("blob_dir", help="Directory containing blobs and metadata.json") parser.add_argument("--file", "-f", help="Specific file to extract") parser.add_argument("--output", "-o", help="Output path for extracted file") parser.add_argument("--list", "-l", action="store_true", help="List all files in blobs") args = parser.parse_args() try: extractor = BlobExtractor(args.blob_dir) if args.list: extractor.list_files() elif args.file: extractor.extract_file(args.file, args.output) else: extractor.list_files() # Default to listing files if no specific action except Exception as e: print(f"Error: {e}") if __name__ == "__main__": main()