app.py

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

# From here down is all the StreamLit UI.
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 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


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:

    answer = load_answer(user_input)
    response = answer.content
    st.subheader("Answer:")

    st.write(response, key=1)
    st.write(answer, key=2)