Update app.py

app.py

@@ -91,17 +91,19 @@ def print_like_dislike(x: gr.LikeData):
 
 # Function to add messages to the chat history
 def add_message(history, message, files):
-    for file in files:
-        history.append(((file,), None))
+    if files is not None:
+        for file in files:
+            history.append(((file,), None))
     if message is not None:
         history.append((message, None))
     return history, gr.update(value=None, interactive=True)
 
 # Function to simulate the bot response
 def bot(history):
-    user_message = history[-1][0]
-    bot_response = chat_response(user_message)
-    history[-1][1] = bot_response
+    if history:
+        user_message = history[-1][0]
+        bot_response = chat_response(user_message)
+        history[-1][1] = bot_response
     return history
 
 fig = random_plot()