def _is_url(url):
try:<EOL><INDENT>return parse_url(url).scheme in _VALID_URLS<EOL><DEDENT>except Exception:<EOL><INDENT>return False<EOL><DEDENT>
Check to see if a URL has a valid protocol.

    Parameters
    ----------
    url : str or unicode

    Returns
    -------
    isurl : bool
        If `url` has a valid protocol return True otherwise False.