specify youtube error instead of just 500

youtube/watch.py

@@ -1,4 +1,5 @@
 from youtube_dl.YoutubeDL import YoutubeDL
+from youtube_dl.extractor.youtube import YoutubeError
 import json
 import urllib
 from string import Template
@@ -289,12 +290,18 @@ more_comments_template = Template('''<a class="page-button more-comments" href="
 download_link_template = Template('''
 <a href="$url"> <span>$ext</span> <span>$resolution</span> <span>$note</span></a>''')
 
+def extract_info(downloader, *args, **kwargs):
+    try:
+        return downloader.extract_info(*args, **kwargs)
+    except YoutubeError as e:
+        return str(e)
+
 def get_watch_page(query_string):
         id = urllib.parse.parse_qs(query_string)['v'][0]
         downloader = YoutubeDL(params={'youtube_include_dash_manifest':False})
         tasks = (
             gevent.spawn(comments.video_comments, id ), 
-            gevent.spawn(downloader.extract_info, "https://www.youtube.com/watch?v=" + id, download=False)
+            gevent.spawn(extract_info, downloader, "https://www.youtube.com/watch?v=" + id, download=False)
         )
         gevent.joinall(tasks)
         comments_info, info = tasks[0].value, tasks[1].value
@@ -308,6 +315,15 @@ def get_watch_page(query_string):
         #info = YoutubeDL().extract_info(url, download=False)
         
         #chosen_format = choose_format(info)
+
+        if isinstance(info, str): # youtube error
+            return common.yt_basic_template.substitute(
+                page_title = "Error",
+                style = "",
+                header = common.get_header(),
+                page = html.escape(info),
+            )
+            
         sorted_formats = sort_formats(info)
         
         video_info = {

youtube_dl/extractor/youtube.py

@@ -49,7 +49,8 @@ from ..utils import (
     uppercase_escape,
     urlencode_postdata,
 )
-
+class YoutubeError(Exception):
+    pass
 
 class YoutubeBaseInfoExtractor(InfoExtractor):
     """Provide base functions for Youtube extractors"""
@@ -1554,6 +1555,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
                     r'"sts"\s*:\s*(\d+)', embed_webpage, 'sts', default=''),
             })
             video_info_url = proto + '://www.youtube.com/get_video_info?' + data
+            
             video_info_webpage = self._download_webpage(
                 video_info_url, video_id,
                 note='Refetching age-gated info webpage',
@@ -1646,7 +1648,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
                     unavailable_message = extract_unavailable_message()
                     if unavailable_message:
                         reason = unavailable_message
-                raise ExtractorError(
+                raise YoutubeError(
                     'YouTube said: %s' % reason,
                     expected=True, video_id=video_id)
             else:
@@ -1895,7 +1897,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             if not error_message:
                 error_message = extract_unavailable_message()
             if error_message:
-                raise ExtractorError(error_message, expected=True)
+                raise YoutubeError(error_message)
             raise ExtractorError('no conn, hlsvp or url_encoded_fmt_stream_map information found in video info')
 
         # uploader