token.write(creds.to_json())
        return creds
ALLOWED_SCHEMAS = {"http", "https"}
ALLOWED_NETLOCK = {
    "youtu.be",
    "m.youtube.com",
    "youtube.com",
    "www.youtube.com",
    "www.youtube-nocookie.com",
    "vid.plus",
}
def _parse_video_id(url: str) -> Optional[str]:
    """Parse a youtube url and return the video id if valid, otherwise None."""
    parsed_url = urlparse(url)
    if parsed_url.scheme not in ALLOWED_SCHEMAS:
        return None
    if parsed_url.netloc not in ALLOWED_NETLOCK:
        return None
    path = parsed_url.path
    if path.endswith("/watch"):
        query = parsed_url.query
        parsed_query = parse_qs(query)
        if "v" in parsed_query:
            ids = parsed_query["v"]
            video_id = ids if isinstance(ids, str) else ids[0]
        else:
            return None
    else:
        path = parsed_url.path.lstrip("/")
        video_id = path.split("/")[-1]
    if len(video_id) != 11:  # Video IDs are 11 characters long
        return None
    return video_id
[docs]class YoutubeLoader(BaseLoader):
    """Load `YouTube` transcripts."""
[docs]    def __init__(
        self,
        video_id: str,
        add_video_info: bool = False,
        language: Union[str, Sequence[str]] = "en",
        translation: str = "en",
        continue_on_failure: bool = False,
    ):
        """Initialize with YouTube video ID."""
        self.video_id = video_id
        self.add_video_info = add_video_info
        self.language = language