Function _bulk_last_updated

scripts/update_lib/deps.py:1126–1172

Get last git commit dates for all paths under Lib/ in one git call. Keys are Lib/-relative paths (e.g. "re/__init__.py", "test/test_os.py", "os.py"), plus directory rollups (e.g. "re", "test/test_zoneinfo"). Returns: Dict mapping Lib/-relative path to date string.

()

@functools.cache
def _bulk_last_updated() -> dict[str, str]:
    """Get last git commit dates for all paths under Lib/ in one git call.

    Keys are Lib/-relative paths (e.g. "re/__init__.py", "test/test_os.py",
    "os.py"), plus directory rollups (e.g. "re", "test/test_zoneinfo").

    Returns:
        Dict mapping Lib/-relative path to date string.
    """
    file_map: dict[str, str] = {}
    try:
        result = subprocess.run(
            ["git", "log", "--format=%cd", "--date=short", "--name-only", "--", "Lib/"],
            capture_output=True,
            text=True,
            timeout=30,
        )
        if result.returncode != 0:
            return file_map
    except Exception:
        return file_map

    current_date = None
    for line in result.stdout.splitlines():
        line = line.strip()
        if not line:
            continue
        # Date lines are YYYY-MM-DD format
        if len(line) == 10 and line[4] == "-" and line[7] == "-":
            current_date = line
        elif current_date and line.startswith("Lib/"):
            # Strip "Lib/" prefix to get Lib-relative key
            rel = line[4:]
            if rel and rel not in file_map:
                file_map[rel] = current_date

    # Pre-compute directory rollups
    dir_map: dict[str, str] = {}
    for filepath, date in file_map.items():
        parts = filepath.split("/")
        for i in range(1, len(parts)):
            dirpath = "/".join(parts[:i])
            if dirpath not in dir_map or date > dir_map[dirpath]:
                dir_map[dirpath] = date

    dir_map.update(file_map)
    return dir_map


@functools.cache