Add playlist sidebar for videos in playlist, including autoplay

2 files changed, 58 insertions, 2 deletions

diff --git a/youtube/yt_data_extract/common.py b/youtube/yt_data_extract/common.py
index 877444e..974d981 100644
--- a/youtube/yt_data_extract/common.py
+++ b/youtube/yt_data_extract/common.py
@@ -73,6 +73,15 @@ def conservative_update(obj, key, value):
     if obj.get(key) is None:
         obj[key] = value
 
+def concat_or_none(*strings):
+    '''Concatenates strings. Returns None if any of the arguments are None'''
+    result = ''
+    for string in strings:
+        if string is None:
+            return None
+        result += string
+    return result
+
 def remove_redirect(url):
     if url is None:
         return None
@@ -268,6 +277,23 @@ def extract_item_info(item, additional_info={}):
                 info['approx_view_count'] = '0'
 
         info['duration'] = extract_str(item.get('lengthText'))
+
+        # if it's an item in a playlist, get its index
+        if 'index' in item: # url has wrong index on playlist page 
+            info['index'] = extract_int(item.get('index'))
+        elif 'indexText' in item:
+            # Current item in playlist has ▶ instead of the actual index, must
+            # dig into url
+            match = re.search(r'index=(\d+)', deep_get(item,
+                'navigationEndpoint', 'commandMetadata', 'webCommandMetadata',
+                'url', default=''))
+            if match is None:   # worth a try then
+                info['index'] = extract_int(item.get('indexText'))
+            else:
+                info['index'] = int(match.group(1))
+        else:
+            info['index'] = None
+
     elif primary_type in ('playlist', 'radio'):
         info['id'] = item.get('playlistId')
         info['video_count'] = extract_int(item.get('videoCount'))
diff --git a/youtube/yt_data_extract/watch_extraction.py b/youtube/yt_data_extract/watch_extraction.py
index bc02313..0b30c91 100644
--- a/youtube/yt_data_extract/watch_extraction.py
+++ b/youtube/yt_data_extract/watch_extraction.py
@@ -2,7 +2,7 @@ from .common import (get, multi_get, deep_get, multi_deep_get,
     liberal_update, conservative_update, remove_redirect, normalize_url,
     extract_str, extract_formatted_text, extract_int, extract_approx_int,
     extract_date, check_missing_keys, extract_item_info, extract_items,
-    extract_response)
+    extract_response, concat_or_none)
 
 import json
 import urllib.parse
@@ -160,7 +160,37 @@ def _extract_watch_info_mobile(top_level):
 
     response = top_level.get('response', {})
 
-    # video info from metadata renderers
+    # this renderer has the stuff visible on the page
+    # check for playlist
+    items, _ = extract_items(response,
+        item_types={'singleColumnWatchNextResults'})
+    if items:
+        watch_next_results = items[0]['singleColumnWatchNextResults']
+        playlist = deep_get(watch_next_results, 'playlist', 'playlist')
+        if playlist is None:
+            info['playlist'] = None
+        else:
+            info['playlist'] = {}
+            info['playlist']['title'] = playlist.get('title')
+            info['playlist']['author'] = extract_str(multi_get(playlist, 
+                'ownerName', 'longBylineText', 'shortBylineText', 'ownerText'))
+            author_id = deep_get(playlist, 'longBylineText', 'runs', 0,
+                'navigationEndpoint', 'browseEndpoint', 'browseId')
+            info['playlist']['author_id'] = author_id
+            if author_id:
+                info['playlist']['author_url'] = concat_or_none(
+                    'https://www.youtube.com/channel/', author_id)
+            info['playlist']['id'] = playlist.get('playlistId')
+            info['playlist']['url'] = concat_or_none(
+                'https://www.youtube.com/playlist?list=',
+                info['playlist']['id'])
+            info['playlist']['video_count'] = playlist.get('totalVideos')
+            info['playlist']['current_index'] = playlist.get('currentIndex')
+            info['playlist']['items'] = [
+                extract_item_info(i) for i in playlist.get('contents', ())]
+
+    # Holds the visible video info. It is inside singleColumnWatchNextResults
+    # but use our convenience function instead
     items, _ = extract_items(response, item_types={'slimVideoMetadataRenderer'})
     if items:
         video_info = items[0]['slimVideoMetadataRenderer']