app.py

import streamlit as st
from langchain_core.messages.chat import ChatMessage
from langchain_core.prompts import ChatPromptTemplate
from langchain_openai import ChatOpenAI
from langchain_core.output_parsers import StrOutputParser
from langchain_teddynote.prompts import load_prompt
from dotenv import load_dotenv
from langchain import hub

load_dotenv()

st.title("나만의 챗GPT💬")


# 처음 1번만 실행하기 위한 코드
if "messages" not in st.session_state:
    st.session_state["messages"] = []

# 사이드바 생성
with st.sidebar:
    clear_btn = st.button("대화 초기화")

    selected_prompt = st.selectbox("프롬프트를 선택해 주세요", ("기본모드"), index=0)


# 이전 대화를 출력
def print_messages():
    for chat_message in st.session_state["messages"]:
        st.chat_message(chat_message.role).write(chat_message.content)


# 새로운 메시지를 추가
def add_message(role, message):
    st.session_state["messages"].append(ChatMessage(role=role, content=message))


# 체인 생성
def create_chain(prompt_type):
    prompt = ChatPromptTemplate.from_messages(
        [
            (
                "system",
                "당신은 친절한 AI 어시스턴트입니다. 다음의 질문에 간결하게 답변해 주세요.",
            ),
            ("user", "#Question:\n{question}"),
        ]
    )

    llm = ChatOpenAI(model_name="gpt-3.5-turbo", temperature=0)

    return prompt | llm | StrOutputParser()


if clear_btn:
    st.session_state["messages"] = []

print_messages()

user_input = st.chat_input("궁금한 내용을 물어보세요!")

if user_input:
    st.chat_message("user").write(user_input)
    chain = create_chain(selected_prompt)

    response = chain.stream({"question": user_input})
    with st.chat_message("assistant"):
        container = st.empty()

        ai_answer = ""
        for token in response:
            ai_answer += token
            container.markdown(ai_answer)

    add_message("user", user_input)
    add_message("assistant", ai_answer)