Update app.py

app.py

@@ -15,7 +15,9 @@ Every now and then, try to use an example from something I'm interested in outsi
 Begin by asking me my name, the topic of our conversation, and the type of assignment I am working on. 
 """
 
-#model = "gpt-3.5-turbo"
+#model = "gpt-3.5-turbo" # free and fast
+#model = "gpt-4" # latest and greatest
+
 def CustomChatGPT(message, history):
     history_openai_format = [{"role": "system", "content": sys_message}]
     for human, assistant in history:
@@ -24,7 +26,7 @@ def CustomChatGPT(message, history):
     history_openai_format.append({"role": "user", "content": message})
     
     response = openai.ChatCompletion.create(
-        model = "gpt-4", # always the latest GPT-4 model
+        model = "gpt-3.5-turbo", 
         messages = history_openai_format,
         temperature = 1.0,
         stream=True