def extra_client_expected_langs():
    """Return language list from http.request.header.Accept-Language,
    ordered by 'q'."""
    result = []
    pieces = REQUEST_ACCEPT_LANGUAGE_RE.split(
        request.headers.get('Accept-Language', ''))
    if pieces[-1]:
        return []
    for i in range(0, 1 - len(pieces), 3):
        first, lang, priority = pieces[i: i + 3]
        if lang == '*':  # TODO: support default language
            return []
        if first:
            return []
        priority = priority and float(priority) or 1.0
        result.append((lang, priority))
    result.sort(key=lambda k: k[1], reverse=True)
    return result
dataset/ETHPy150Open gengo/decanter/decanter/lib/i18n.py/extra_client_expected_langs/swapped operands of `-`