#!/usr/bin/env python
# coding: utf-8

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#!pip install langchain


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#!pip install streamlit


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#!pip install PyPDF2


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#!pip install langchain-openai


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import os
from PyPDF2 import PdfReader
import streamlit as st
from langchain.text_splitter import CharacterTextSplitter
from langchain_openai import OpenAIEmbeddings
from langchain import FAISS
from langchain.chains.question_answering import load_qa_chain
from langchain.chat_models import ChatOpenAI
from langchain.callbacks import get_openai_callback
api_key="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"

def process_text(text): 
#CharacterTextSplitter를 사용하여 텍스트를 청크로 분할
    text_splitter = CharacterTextSplitter(
        separator="\n",
        chunk_size=1000,
        chunk_overlap=200,
        length_function=len
    )
    chunks = text_splitter.split_text(text)

    #임베딩 처리(벡터 변환), 임베딩은 OpenAI 모델을 사용합니다.
    embeddings = OpenAIEmbeddings(model="text-embedding-ada-002", api_key=api_key)
    documents = FAISS.from_texts(chunks, embeddings)
    return documents

def main():  #streamlit을 이용한 웹사이트 생성
    st.title("📄PDF 요약하기")
    st.divider()

    pdf = st.file_uploader('PDF파일을 업로드해주세요', type='pdf')

    if pdf is not None:
        pdf_reader = PdfReader(pdf)
        text = ""   # 텍스트 변수에 PDF 내용을 저장
        for page in pdf_reader.pages:
            text += page.extract_text()

        documents = process_text(text)
        query = "업로드된 PDF 파일의 내용을 약 3~5문장으로 요약해주세요."  # LLM에 PDF파일 요약 요청

        if query:
            docs = documents.similarity_search(query)
            llm = ChatOpenAI(model="gpt-3.5-turbo-16k", api_key=api_key, temperature=0.1)
            chain = load_qa_chain(llm, chain_type='stuff')

            with get_openai_callback() as cost:
                response = chain.run(input_documents=docs, question=query)
                print(cost)

            st.subheader('--요약 결과--:')
            st.write(response)

if __name__ == '__main__':
    main()


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