import re from smolagents import tool from youtube_transcript_api import YouTubeTranscriptApi, TranscriptsDisabled, NoTranscriptFound def _extract_video_id(youtube_url: str) -> str | None: """ Extracts the YouTube video ID from a URL. Handles standard, shortened, and embed URLs. """ # Standard URL: https://www.youtube.com/watch?v=VIDEO_ID match = re.search(r"watch\?v=([^&]+)", youtube_url) if match: return match.group(1) # Shortened URL: https://youtu.be/VIDEO_ID match = re.search(r"youtu\.be/([^?&]+)", youtube_url) if match: return match.group(1) # Embed URL: https://www.youtube.com/embed/VIDEO_ID match = re.search(r"youtube\.com/embed/([^?&]+)", youtube_url) if match: return match.group(1) # Video ID directly passed # Basic check for a valid video ID format if re.fullmatch(r"^[a-zA-Z0-9_-]{11}$", youtube_url): return youtube_url return None @tool def get_youtube_video_transcript(video_url_or_id: str, lang_preference: list[str] = ['en', 'en-US', 'en-GB']) -> str: """ Retrieves the transcript for a given YouTube video URL or video ID. It tries to fetch the transcript in the preferred languages first (defaulting to English). Args: video_url_or_id (str): The full YouTube video URL (e.g., "https://www.youtube.com/watch?v=VIDEO_ID") or just the 11-character video ID. lang_preference (list[str]): A list of language codes to try for the transcript, in order of preference. Defaults to ['en', 'en-US', 'en-GB']. Returns: str: The concatenated transcript text if successful. An error message string if the transcript cannot be fetched (e.g., disabled, not found, invalid ID). """ video_id = _extract_video_id(video_url_or_id) if not video_id: return f"Error: Invalid YouTube video URL or ID provided: '{video_url_or_id}'. Could not extract a valid video ID." try: # Fetch available transcripts transcript_list = YouTubeTranscriptApi.list_transcripts(video_id) # Try to find transcript in preferred languages transcript = None for lang_code in lang_preference: try: transcript = transcript_list.find_transcript([lang_code]) break except NoTranscriptFound: continue # If not found in preferred, try generated transcript in preferred languages if not transcript: for lang_code in lang_preference: try: transcript = transcript_list.find_generated_transcript([ lang_code]) break except NoTranscriptFound: continue # If still not found, try any available English transcript if not transcript: try: transcript = transcript_list.find_transcript( ['en', 'en-US', 'en-GB', 'en-AU', 'en-CA', 'en-IN']) except NoTranscriptFound: pass # Continue to try any generated English transcript if not transcript: try: transcript = transcript_list.find_generated_transcript( ['en', 'en-US', 'en-GB', 'en-AU', 'en-CA', 'en-IN']) except NoTranscriptFound: # If no English transcript, grab the first available original language transcript try: print( f"YouTubeTool: No English transcript found for {video_id}. Trying first available original language.") original_lang_transcript = next( iter(transcript_list)) # get the first one transcript = original_lang_transcript except StopIteration: # No transcripts at all return f"Error: No transcripts at all seem to be available for video ID '{video_id}'." except NoTranscriptFound: # Should be caught by StopIteration if list is empty return f"Error: No transcripts found for video ID '{video_id}' after trying preferred and English languages." if transcript: full_transcript_data = transcript.fetch() # Concatenate all text segments into a single string transcript_text = " ".join([segment['text'] for segment in full_transcript_data]) return transcript_text else: # This case should ideally be covered by the fallbacks above return f"Error: Could not find a suitable transcript for video ID '{video_id}' in languages: {lang_preference} or English." except TranscriptsDisabled: return f"Error: Transcripts are disabled for video ID '{video_id}'." # This might catch cases where video ID is valid but has zero transcripts at all. except NoTranscriptFound: return f"Error: No transcripts whatsoever could be found for video ID '{video_id}'. The video might not have any captions or transcripts." except Exception as e: # Catch any other unexpected errors from the API or video ID issues not caught by regex error_type = type(e).__name__ # Check for common youtube_transcript_api specific errors not explicitly caught if any # Heuristic for bad ID if "video ID" in str(e).lower() or "parameter" in str(e).lower(): return f"Error: Could not retrieve transcript for video ID '{video_id}'. It might be an invalid ID or the video is private/deleted. (API Error: {error_type})" return f"Error: An unexpected error occurred while fetching transcript for video ID '{video_id}': {error_type} - {str(e)}" if __name__ == '__main__': # Example Usage: test_video_url = "https://www.youtube.com/watch?v=1htKBjuUWec" # Stargate SG-1 Clip # Rick Astley (often has transcripts disabled or removed for fun) test_video_url_no_transcript = "https://www.youtube.com/watch?v=dQw4w9WgXcQ" test_video_id_only = "1htKBjuUWec" test_video_short_url = "https://youtu.be/1htKBjuUWec" test_video_invalid_id = "invalidID123" print(f"--- Testing with URL: {test_video_url} ---") transcript = get_youtube_video_transcript(test_video_url) if not transcript.startswith("Error:"): print(f"Transcript (first 300 chars): {transcript[:300]}...") else: print(transcript) print( f"\n--- Testing with Rick Astley URL: {test_video_url_no_transcript} ---") transcript_rick = get_youtube_video_transcript( test_video_url_no_transcript) print(transcript_rick) # Expected to often fail or have limited transcripts print(f"\n--- Testing with Video ID only: {test_video_id_only} ---") transcript_id = get_youtube_video_transcript(test_video_id_only) if not transcript_id.startswith("Error:"): print(f"Transcript (first 300 chars): {transcript_id[:300]}...") else: print(transcript_id) print(f"\n--- Testing with Short URL: {test_video_short_url} ---") transcript_short = get_youtube_video_transcript(test_video_short_url) if not transcript_short.startswith("Error:"): print(f"Transcript (first 300 chars): {transcript_short[:300]}...") else: print(transcript_short) print(f"\n--- Testing with Invalid Video ID: {test_video_invalid_id} ---") transcript_invalid = get_youtube_video_transcript(test_video_invalid_id) print(transcript_invalid) # Example of a video that might only have auto-generated transcripts or transcripts in other languages test_video_non_english_primary = "https://www.youtube.com/watch?v=xU7rVbnefj0" print( f"\n--- Testing with non-English primary video: {test_video_non_english_primary} ---") transcript_non_eng = get_youtube_video_transcript( test_video_non_english_primary) if not transcript_non_eng.startswith("Error:"): print(f"Transcript (first 300 chars): {transcript_non_eng[:300]}...") else: print(transcript_non_eng)