Update app.py

app.py

@@ -33,10 +33,12 @@ def process_file(file):
         return None
 
 def respond(message, chat_history, files):
-    processed_files = [process_file(file) for file in files if file is not None]
+    processed_files = []
+    if files:
+        processed_files = [process_file(file) for file in files if file is not None]
     
     if processed_files:
-        response = chat_session.send_message([message, *processed_files])
+        response = chat_session.send_message([message] + processed_files)
     else:
         response = chat_session.send_message(message)