Use traverse_obj in another place as well

Co-authored-by: dirkf <fieldhouse@gmx.net>

youtube_dl/extractor/npo.py

@@ -5,7 +5,7 @@ import json
 import re
 
 from .common import InfoExtractor
-from ..utils import ExtractorError
+from ..utils import ExtractorError, join_nonempty, traverse_obj
 
 
 class NPOIE(InfoExtractor):
@@ -95,7 +95,7 @@ class NPOIE(InfoExtractor):
                 },
                 fatal=False,
             )
-            stream_url = stream_link.get('stream', {}).get('streamURL')
+            stream_url = traverse_obj(stream_link, ('stream', 'streamURL'))
             formats.extend(self._extract_mpd_formats(stream_url, slug, mpd_id='dash', fatal=False))
         return formats
 
@@ -140,9 +140,9 @@ class BNNVaraIE(NPOIE):
 
         return {
             'id': product_id,
-            'title': media.get('data', {}).get('player', {}).get('title'),
+            'title': traverse_obj(media, ('data', 'player', 'title')),
             'formats': formats,
-            'thumbnail': media.get('data', {}).get('player', {}).get('image').get('url'),
+            'thumbnail': traverse_obj(media, ('data', 'player', 'image', 'url')),
         }
 
 
@@ -160,7 +160,7 @@ class ONIE(NPOIE):
 
     def _real_extract(self, url):
         video_id = url.rstrip('/').split('/')[-1]
-        page, _ = self._download_webpage_handle(url, video_id)
+        page = self._download_webpage(url, video_id)
         results = re.findall("page: '(.+)'", page)
         formats = []
         for result in results:
@@ -241,7 +241,7 @@ class SchoolTVIE(NPOIE):
 
         return {
             'id': video_id,
-            'title': metadata.get('title', '') + ' - ' + metadata.get('subtitle', ''),
+            'title': join_nonempty('title', 'subtitle', from_dict=metadata),
             'description': metadata.get('description') or metadata.get('short_description'),
             'formats': formats,
         }