def build_url(s_o, image_mode):
            _urls = [[], []]
            _url = s_o[image_mode]
            if _url and _url.startswith('http'):
                if 'poster' == image_mode:
                    _url = re.sub('posters', '_cache/posters', _url)
                elif 'banner' == image_mode:
                    _url = re.sub('graphical', '_cache/graphical', _url)
                _urls[0].append(_url)

                try:
                    alt_url = '%swww.%s%s' % re.findall(
                        r'(https?://)(?:artworks\.)?(thetvdb\.[^/]+/banners/[^\d]+[^.]+)(?:_t)(.*)', _url)[0][0:3]
                    if alt_url not in _urls[0]:
                        _urls[1].append(alt_url)
                except (IndexError, Exception):
                    try:
                        alt_url = '%sartworks.%s_t%s' % re.findall(
                            r'(https?://)(?:www\.)?(thetvdb\.[^/]+/banners/[^\d]+[^.]+)(.*)', _url)[0][0:3]
                        if alt_url not in _urls[0]:
                            _urls[1].append(alt_url)
                    except (IndexError, Exception):
                        pass
            return _urls