app.py

import streamlit as st
from langchain.chat_models import ChatOpenAI
from langchain.schema import (AIMessage, HumanMessage, SystemMessage)

st.set_page_config(page_title="LangChain Demo", page_icon=":robot:")
st.header("Hey, I'm your Chat GPT")

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

chat = ChatOpenAI(temperature=0)

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


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

user_input = get_text()

submit = st.button("Generate")

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