def to_abspath(path: Union[str, List[str], None], check_path_exist: bool = False) -> Union[str, List[str], None]:
    """Check the path for validity and convert it to an absolute path.

    Args:
        path: The path to be checked/converted
        check_path_exist: Whether to check if the path exists

    Returns:
        Absolute path
    """
    if path is None:
        return
    elif isinstance(path, str):
        # Remove user path prefix and convert to absolute path.
        path = os.path.abspath(os.path.expanduser(path))
        if check_path_exist and not os.path.exists(path):
            raise FileNotFoundError(f"path: '{path}'")
        return path
    assert isinstance(path, list), f'path: {path}'
    res = []
    for v in path:
        res.append(to_abspath(v, check_path_exist))
    return res
Check the path for validity and convert it to an absolute path.

    Args:
        path: The path to be checked/converted
        check_path_exist: Whether to check if the path exists

    Returns:
        Absolute path
    
swift/llm/argument/base_args/utils.py