Update app.py

app.py

@@ -5,19 +5,16 @@ from transformers import (
     pipeline,
     AutoTokenizer,
     TextIteratorStreamer,
-    BitsAndBytesConfig
 )
 
 
 def chat_history(history) -> str:
-    messages = [
-        {
-            "role": ("user" if i % 2 == 0 else "assistant"),
-            "content": dialog[i % 2]
-        }
-        for i, dialog in enumerate(history) for _ in (0, 1) if dialog[i % 2]
-    ]
+    messages = []
 
+    for dialog in history:
+        for i, message in enumerate(dialog):
+            role = "user" if i % 2 == 0 else "assistant"
+            messages.append({"role": role, "content": message})
     return pipe.tokenizer.apply_chat_template(
         messages, tokenize=False, add_generation_prompt=True
     )
@@ -45,7 +42,7 @@ def launch_app(pipe, streamer):
         clear = gr.Button("Clear")
 
         def user(user_message, history):
-            return "", history + [[user_message, None]]
+            return "", history + [[user_message, ""]]
 
         def bot(history):
             prompt = chat_history(history)