$3=227(209):

def _parse_seq_preheader(line):
    """
    $3=227(209):
    """
    match = re.match(r"\$ (\d+) = (\d+) \( (\d+) \):", line, re.VERBOSE)
    if not match:
        raise ValueError("Unparseable header: " + line)
    index, this_len, query_len = match.groups()
    return map(int, (index, this_len, query_len))