app.py

import streamlit as st

from langchain.chat_models import ChatOpenAI
from langchain.schema import AIMessage, HumanMessage, SystemMessage

#streamlit UI code
st.set_page_config(page_title="Demo Chat App", page_icon=":robot:")
st.header("This is my simple chat application, pls try..")

if "sessionMessages" not in st.session_state:
  st.session_state.sessionMessages = [
  SystemMessage(content="You are a helpful assistant.")
  ]

def load_answer(question):
  st.session_state.sessionMessages.append(HumanMessage(content=question))
  assistant_answer = chat(st.session_state.sessionMessages)
  st.session_state.sessionMessages.append(AIMessage(content=assistant_answer.content))
  return assistant_answer.content

def get_text():
  input_text = st.text_input("You:", key=input)
  return input_text

chat = ChatOpenAI(temperature=0)

user_input = get_text()
submit = st.button('Generate')

if submit:
  response = load_answer(user_input)
  st.subheader("AI Assistant:")
  st.write(response, key=1)