def urljoin(*parts):
    """Combines parts of a URL into a fully path.

    Removes any additional trailing or leading "/" characters.

    Example:
      urljoin('abc.com', 'path/', 'file.txt) -> 'abc.com/path/file.txt'

    Args:
        *parts: Any sequence of parts of a URL to join

    Returns:
        Concatenate the parts of the URL together, separated by "/".
    """
    return "/".join(str(part).strip("/") for part in parts)