Update app.py

app.py

@@ -9,7 +9,7 @@ client = InferenceClient("mistralai/Mixtral-8x7B-Instruct-v0.1")
 
 def format_prompt(message, history):
     prompt = "<s>"
-    if not history == (None,None):
+    if history:
         for user_prompt, bot_response in history:
             prompt += f"[INST] {user_prompt} [/INST]"
             prompt += f" {bot_response}</s> "
@@ -19,7 +19,7 @@ def format_prompt(message, history):
 
 def chat_inf(system_prompt,prompt,history):
     if not history:
-        history = (None,None)
+        history = []
         
     seed = random.randint(1,1111111111111111)
     generate_kwargs = dict(
@@ -36,7 +36,7 @@ def chat_inf(system_prompt,prompt,history):
     output = ""
     for response in stream:
         output += response.token.text
-        hist=[history,(prompt,output)]
+        hist=[history,[prompt,output]]
         yield hist