YouTube Usage example comments (#10106)

* YouTube Usage example comments Signed-off-by: Glenn Jocher <glenn.jocher@ultralytics.com> * Update dataloaders.py Signed-off-by: Glenn Jocher <glenn.jocher@ultralytics.com> Signed-off-by: Glenn Jocher <glenn.jocher@ultralytics.com>

YouTube Usage example comments (#10106)
c1fcfe8c · Glenn Jocher · GitHub · 892c4cd4 · c1fcfe8c
--- a/utils/dataloaders.py
+++ b/utils/dataloaders.py
@@ -353,6 +353,7 @@ class LoadStreams:
            # Start thread to read frames from video stream
            st = f'{i + 1}/{n}: {s}... '
            if urlparse(s).hostname in ('www.youtube.com', 'youtube.com', 'youtu.be'):  # if source is YouTube video
+                # YouTube format i.e. 'https://www.youtube.com/watch?v=Zgi9g1ksQHc' or 'https://youtu.be/Zgi9g1ksQHc'
                check_requirements(('pafy', 'youtube_dl==2020.12.2'))
                import pafy
                s = pafy.new(s).getbest(preftype="mp4").url  # YouTube URL