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【Langchain】+ 【baichuan】实现领域知识库【RAG】问答系统

news 2025/6/28 3:20:23

本项目使用Langchain 和 baichuan 大模型，结合领域百科词条数据（用xlsx保存），简单地实现了领域百科问答实现。

from langchain.text_splitter import CharacterTextSplitter, RecursiveCharacterTextSplitter
from langchain_community.embeddings import OpenAIEmbeddings, SentenceTransformerEmbeddings
from langchain_community.vectorstores import Chroma, FAISS
from langchain_community.llms import OpenAI, Baichuan
from langchain_community.chat_models import ChatOpenAI, ChatBaichuan
from langchain.memory import ConversationBufferWindowMemory
from langchain.chains import ConversationalRetrievalChain, RetrievalQA
#import langchain_community import chat_models
#print(chat_models.__all__)import streamlit as st
import pandas as pd
import os
import warnings
import time
warnings.filterwarnings('ignore')# 对存储了领域百科词条的xlsx文件进行解析
def get_xlsx_text(xlsx_file):df = pd.read_excel(xlsx_file, engine='openpyxl')text = ""for index, row in df.iterrows():text += row['title'].replace('\n', '')text += row['content'].replace('\n', '')text += '\n\n'return text# Splits a given text into smaller chunks based on specified conditions
def get_text_chunks(text):text_splitter = RecursiveCharacterTextSplitter(separators="\n\n",chunk_size=1000,chunk_overlap=200,length_function=len)chunks = text_splitter.split_text(text)return chunks# 对切分的文本块构建编码向量并存储到FASISS
# Generates embeddings for given text chunks and creates a vector store using FAISS
def get_vectorstore(text_chunks):# embeddings = OpenAIEmbeddings() #有经济条件的可以使用　opanaiembendingembeddings = SentenceTransformerEmbeddings(model_name='all-MiniLM-L6-v2')vectorstore = FAISS.from_texts(texts=text_chunks, embedding=embeddings)return vectorstore
# Initializes a conversation chain with a given vector store# 对切分的文本块构建编码向量并存储到Chroma
# Generates embeddings for given text chunks and creates a vector store using Chroma
def get_vectorstore_chroma(text_chunks):# embeddings = OpenAIEmbeddings()embeddings = SentenceTransformerEmbeddings(model_name='all-MiniLM-L6-v2')vectorstore = Chroma.from_texts(texts=text_chunks, embedding=embeddings)return vectorstoredef get_conversation_chain_baichuan(vectorstore):memory = ConversationBufferWindowMemory(memory_key='chat_history', return_message=True)　# 设置记忆存储器conversation_chain = ConversationalRetrievalChain.from_llm(llm=Baichuan(temperature=temperature_input, model_name=model_select),retriever=vectorstore.as_retriever(),get_chat_history=lambda h: h,memory=memory)return conversation_chainos.environ["http_proxy"] = "http://127.0.0.1:7890"
os.environ["https_proxy"] = "http://127.0.0.1:7890"# langchain 可以通过设置环境变量来设置参数
os.environ['BAICHUAN_API_KEY'] = 'sk-88888888888888888888888888888888'
temperature_input = 0.7
model_select = 'Baichuan2-Turbo-192K'
raw_text = get_xlsx_text('领域文件/twiki百科问答.xlsx')text_chunks = get_text_chunks(raw_text)
vectorstore = get_vectorstore_chroma(text_chunks)
# Create conversation chain
qa = get_conversation_chain_baichuan(vectorstore)
questions = ["什么是森林经营项目?","风电项目开发过程中需要的主要资料?","什么是ESG"
]
for question in questions:result = qa(question)print(f"**Question**: {question} \n")print(f"**Answer__**: {result['answer']} \n")