[fix] youtube_noapi : don't crash when there is no content

content_xpath = './/div[@class="yt-lockup-content"]/div[@class="yt-lockup-description yt-ui-ellipsis yt-ui-ellipsis-2"]'

# get element in list or default value

def list_get(a_list, index, default=None):

    if len(a_list) > index:

        return a_list[index]

    else:

        return default

# returns extract_text on the first result selected by the xpath or None

def extract_text_from_dom(result, xpath):

    r = result.xpath(xpath)

    if len(r) > 0:

        return extract_text(r[0])

    return None

# do search-request

def request(query, params):

    params['url'] = search_url.format(query=quote_plus(query),

    # parse results

    for result in dom.xpath(results_xpath):

        videoid = result.xpath('@data-context-item-id')[0]

        videoid = list_get(result.xpath('@data-context-item-id'), 0)

        if videoid is not None:

            url = base_youtube_url + videoid

            thumbnail = 'https://i.ytimg.com/vi/' + videoid + '/hqdefault.jpg'

        title = extract_text(result.xpath(title_xpath)[0])

        content = extract_text(result.xpath(content_xpath)[0])

            title = extract_text_from_dom(result, title_xpath) or videoid

            content = extract_text_from_dom(result, content_xpath)

            embedded = embedded_url.format(videoid=videoid)