Update app.py

app.py

@@ -112,9 +112,11 @@ def get_completion(message,history):
 
     history_openai_format = []
     for human, assistant in history:
-        # check if there is image info in the history message
-        if isinstance(human, tuple):
+        # check if there is image info in the history message or empty history messages
+        
+        if isinstance(human, tuple) or human == "" or assistant is None:
             continue
+            
         history_openai_format.append({"role": "user", "content": human })
         history_openai_format.append({"role": "assistant", "content":assistant})
     history_openai_format.append({"role": "user", "content": user_message})