Llama3 & RAG

Local RAG 실무에서 활용 가능 (PDF 파일)

main.py

#!/bin/env python3
import os
import tempfile
import streamlit as st
from streamlit_chat import message

from rag import ChatPDF

# head title 설정
st.set_page_config(page_title="ChatPDF")

def read_and_save_file():
    st.session_state["assistant"].clear()
    st.session_state["messages"] = []
    st.session_state["user_input"] = ""

    for file in st.session_state["file_uploader"]:
        with tempfile.NamedTemporaryFile(delete=False) as tf:
            tf.write(file.getbuffer())
            file_path = tf.name

        with st.session_state["ingestion_spinner"], st.spinner(f"Ingesting {file.name}"):
            st.session_state["assistant"].ingest(file_path)
        os.remove(file_path)

def display_messages():
    st.subheader("Chat")
    for i, (msg, is_user) in enumerate(st.session_state["messages"]):
        message(msg, is_user=is_user, key=str(i))
    st.session_state["thinking_spinner"] = st.empty()

def process_input():
    if st.session_state["user_input"] and len(st.session_state["user_input"].strip()) > 0:
        user_text = st.session_state["user_input"].strip()
        with st.session_state["thinking_spinner"], st.spinner(f"Thinking"):
            agent_text = st.session_state["assistant"].ask(user_text)

        st.session_state["messages"].append((user_text, True))
        st.session_state["messages"].append((agent_text, False))

def main():
    if len(st.session_state) == 0:
        st.session_state["messages"] = []
        st.session_state["assistant"] = ChatPDF()

    st.header("ChatPDF")

    st.subheader("Upload a document")

    # 업로드
    st.file_uploader(
        "Upload document",
        type=["pdf"],
        key="file_uploader",
        on_change=read_and_save_file,
        label_visibility="collapsed",
        accept_multiple_files=True,
    )

    # 스피너
    st.session_state["ingestion_spinner"] = st.empty()

    display_messages()
    st.text_input("Message", key="user_input", on_change=process_input)

if __name__ == "__main__":
    main()

rag.py

from langchain_community.vectorstores import Chroma
from langchain_community.chat_models import ChatOllama
from langchain_community.embeddings import FastEmbedEmbeddings
from langchain.schema.output_parser import StrOutputParser
from langchain_community.document_loaders import PyPDFLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain.schema.runnable import RunnablePassthrough
from langchain.prompts import PromptTemplate
from langchain_community.vectorstores.utils import filter_complex_metadata
from langchain.globals import set_verbose

class ChatPDF:
    vector_store = None
    retriever = None
    chain = None

    def __init__(self):

        # UserWarning:
        # Importing verbose from langchain root module is no longer supported. Please use langchain.globals.set_verbose() / langchain.globals.get_verbose() instead.
        set_verbose(True)

        self.model = ChatOllama(model="llama3")
        self.text_splitter = RecursiveCharacterTextSplitter(chunk_size=1024, chunk_overlap=100)
        self.prompt = PromptTemplate.from_template(
            """
            <s> [INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context 
            to answer the question. If you don't know the answer, just say that you don't know. Use three sentences
             maximum and keep the answer concise. [/INST] </s> 
            [INST] Question: {question} 
            Context: {context} 
            Answer: [/INST]
            """
        )

    def ingest(self, pdf_file_path: str):
        docs = PyPDFLoader(file_path=pdf_file_path).load()
        chunks = self.text_splitter.split_documents(docs)
        chunks = filter_complex_metadata(chunks)

        vector_store = Chroma.from_documents(documents=chunks, embedding=FastEmbedEmbeddings())
        self.retriever = vector_store.as_retriever(
            search_type="similarity_score_threshold",
            search_kwargs={
                "k": 3,
                "score_threshold": 0.5,
            },
        )

        self.chain = ({"context": self.retriever, "question": RunnablePassthrough()}
                      | self.prompt
                      | self.model
                      | StrOutputParser())

    def ask(self, query: str):
        if not self.chain:
            return "Please, add a PDF document first."

        return self.chain.invoke(query)

    def clear(self):
        self.vector_store = None
        self.retriever = None
        self.chain = None

실행

(local-rag-example-py3.11) snoopy_kr@iMac local-rag-example % streamlit run main.py