Repository: yt-dlp/yt-dlp
File: yt_dlp/extractor/twitcasting.py (Python)

Code before:
    }]

    def _real_extract(self, url):
        uploader_id = self._match_id(url)
        self.to_screen(
            'Downloading live video of user {0}. '
            'Pass "https://twitcasting.tv/{0}/show" to download the history'.format(uploader_id))

        webpage = self._download_webpage(url, uploader_id)
        is_live = 'data-is-onlive="true"' in webpage
        if not is_live:
            raise UserNotLive(video_id=uploader_id)
        current_live = self._search_regex(
            (r'data-type="movie" data-id="(\d+)">',
             r'tw-sound-flag-open-link" data-id="(\d+)" style=',
             r'data-movie-id="(\d+)"',),
            webpage, 'current live ID', default=None)
        if not current_live:
            # fetch unfiltered /show to find running livestreams; we can't get ID of the password-protected livestream above
            webpage = self._download_webpage(
                f'https://twitcasting.tv/{uploader_id}/show/', uploader_id,
                note='Downloading live history')
            is_live = self._search_regex(
                (r'(?s)(<span\s*class="tw-movie-thumbnail-badge"\s*data-status="live">\s*LIVE)',
                 r'data-is-onlive="true"',),
                webpage, 'is live?', default=None)
            if is_live:
                # get the first live; running live is always at the first
                current_live = self._search_regex(
                    r'(?s)<a\s+class="tw-movie-thumbnail"\s*href="/[^/]+/movie/(?P<video_id>\d+)"\s*>.+?</a>',
                    webpage, 'current live ID 2', default=None, group='video_id')
        if not current_live:
            raise UserNotLive(video_id=uploader_id)
        return self.url_result('https://twitcasting.tv/%s/movie/%s' % (uploader_id, current_live))


class TwitCastingUserIE(InfoExtractor):
    _VALID_URL = r'https?://(?:[^/?#]+\.)?twitcasting\.tv/(?P<id>[^/?#]+)/(:?show|archive)/?(?:[#?]|$)'
    _TESTS = [{
        'url': 'https://twitcasting.tv/natsuiromatsuri/archive/',
        'info_dict': {
            'id': 'natsuiromatsuri',
            'title': 'natsuiromatsuri - Live History',
        },
        'playlist_mincount': 235,
    }, {
        'url': 'https://twitcasting.tv/noriyukicas/show',
        'only_matching': True,
    }]

    def _entries(self, uploader_id):

Review comment (suggestion):
`_search_regex` will throw if we don't have a capture group in the 2nd pattern
```suggestion
            is_live = self._search_regex(
                (r'(?s)(<span\s*class="tw-movie-thumbnail-badge"\s*data-status="live">\s*LIVE)',
                 r'(data-is-onlive="true")'),
                webpage, 'is live?', default=None)
```

Code after:
        'expected_exception': 'UserNotLive',
    }]

    _PROTECTED_LIVE_RE = r'(?s)(<span\s*class="tw-movie-thumbnail2-badge"\s*data-status="live">\s*LIVE)'

    def _real_extract(self, url):
        uploader_id = self._match_id(url)
        self.to_screen(
            'Downloading live video of user {0}. '
            'Pass "https://twitcasting.tv/{0}/show" to download the history'.format(uploader_id))

        webpage = self._download_webpage(url, uploader_id)
        is_live = self._search_regex(  # first pattern is for public live
            (r'(data-is-onlive="true")', self._PROTECTED_LIVE_RE), webpage, 'is live?', default=None)
        current_live = int_or_none(self._search_regex(
            (r'data-type="movie" data-id="(\d+)">',  # not available?
             r'tw-sound-flag-open-link" data-id="(\d+)" style=',  # not available?
             r'data-movie-id="(\d+)"'),  # if not currently live, value may be 0
            webpage, 'current live ID', default=None))
        if is_live and not current_live:
            # fetch unfiltered /show to find running livestreams; we can't get ID of the password-protected livestream above
            webpage = self._download_webpage(
                f'https://twitcasting.tv/{uploader_id}/show/', uploader_id,
                note='Downloading live history')
            is_live = self._search_regex(self._PROTECTED_LIVE_RE, webpage, 'is live?', default=None)
            if is_live:
                # get the first live; running live is always at the first
                current_live = self._search_regex(
                    r'(?s)<a\s+class="tw-movie-thumbnail2"\s*href="/[^/]+/movie/(?P<video_id>\d+)"\s*>.+?</a>',
                    webpage, 'current live ID 2', default=None, group='video_id')
        if not current_live:
            raise UserNotLive(video_id=uploader_id)
        return self.url_result(f'https://twitcasting.tv/{uploader_id}/movie/{current_live}', TwitCastingIE)


class TwitCastingUserIE(InfoExtractor):
    _VALID_URL = r'https?://(?:[^/?#]+\.)?twitcasting\.tv/(?P<id>[^/?#]+)/(:?show|archive)/?(?:[#?]|$)'
    _TESTS = [{
        'url': 'https://twitcasting.tv/natsuiromatsuri/archive/',
        'info_dict': {
            'id': 'natsuiromatsuri',
            'title': 'natsuiromatsuri - Live History',
        },
        'playlist_mincount': 235,
    }, {
        'url': 'https://twitcasting.tv/noriyukicas/show',
        'only_matching': True,
    }]

    def _entries(self, uploader_id):
        base_url = next_url = 'https://twitcasting.tv/%s/show' % uploader_id