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 am your Chat GPT")

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))

    model_response = chat(st.session_state.sessionMessages)
    st.session_state.sessionMessages.append(model_response)
    
    return model_response.content
    

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

chat = ChatOpenAI(temperature = 0)

user_input = get_text()

submit = st.button("Generate")

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