Update app.py

app.py

@@ -52,9 +52,8 @@ def generate(question):
     answer = ret['answer']
     sources = ret['sources']
     embed_video_html = ''
-    if sources is not None:
-        if isinstance(sources, str):
-            sources = [sources]
+    if sources is not None and len(sources) > 0:
+        sources = [s.strip() for s in sources.split(',')]
         for source in sources:
             embed_video_html += f'''
                 <iframe width="560" height="315" src="https://www.youtube.com/embed/{source}"