Backup The npm cache to Zip (Python)

#!/usr/bin/env python3
"""
backup_npm_cache_to_zip.py

Backs up the npm cache to a timestamped zip archive before you clear it.

Usage:
    python backup_npm_cache_to_zip.py <destination_folder>
"""

import os
import sys
import zipfile
from datetime import datetime
from pathlib import Path


def main() -> None:
    if len(sys.argv) < 2:
        sys.exit("Usage: python backup_npm_cache_to_zip.py <destination_folder>")

    source = Path(os.path.expandvars(r'%APPDATA%\npm-cache'))
    destination_folder = Path(sys.argv[1])

    if not source.exists():
        print(f"{source} does not exist on this machine.")
        return

    destination_folder.mkdir(parents=True, exist_ok=True)
    timestamp = datetime.now().strftime("%Y%m%d-%H%M%S")
    zip_path = destination_folder / f"npm_cache_{timestamp}.zip"

    # Zip file-by-file (rather than shutil.make_archive) so a single locked
    # or in-use file doesn't abort the whole backup — it's just skipped.
    added, skipped = 0, 0
    with zipfile.ZipFile(zip_path, "w", zipfile.ZIP_DEFLATED) as zf:
        for file in source.rglob("*"):
            if not file.is_file():
                continue
            try:
                zf.write(file, file.relative_to(source))
                added += 1
            except OSError:
                skipped += 1

    print(f"Backed up to {zip_path} ({added} file(s) added, {skipped} skipped)")


if __name__ == "__main__":
    main()