reference
- https://huggingface.co/spaces/ChallengeHub/Chinese-LangChain
- https://huggingface.co/spaces/thomas-yanxin/LangChain-ChatLLM
- https://huggingface.co/shibing624/text2vec-base-chinese
- https://python.langchain.com/docs/integrations/vectorstores/faiss
principle
- Local knowledge (txt md word pdf, etc.) → local vector persistence (redis mulvs elasticsearch local pg)
- Read knowledge → Similarity search → Make summary inferences
code testing
import os
import gradio as gr
import nltk
import sentence_transformers
import torch
from langchain.chains import RetrievalQA
from langchain.document_loaders import UnstructuredFileLoader
from langchain.embeddings import JinaEmbeddings
from langchain.embeddings.huggingface import HuggingFaceEmbeddings
from langchain.prompts import PromptTemplate
from langchain.prompts.prompt import PromptTemplate
from langchain.vectorstores import FAISS
from langchain import OpenAI
import re
from typing import List
import openai
from langchain.text_splitter import CharacterTextSplitter
class LocalKnowledge:
def __init__(self, local_file_path="./README.md", embedding_model_name_or_path="GanymedeNil/text2vec-base-chinese"):
self.local_file_path = local_file_path
self.embedding_model_name_or_path = embedding_model_name_or_path
@property
def embeddings(self):
return HuggingFaceEmbeddings(model_name=self.embedding_model_name_or_path)
@property
def docs(self):
from langchain.document_loaders import TextLoader
loader = TextLoader("./README.md", encoding="UTF-8")
documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=100, chunk_overlap=0)
docs = text_splitter.split_documents(documents)
return docs
def init_knowledge_vector_store(self):
return FAISS.from_documents(self.docs, self.embeddings)
@classmethod
def get_knowledge_based_answer(cls, query,
vector_store,
llm,
VECTOR_SEARCH_TOP_K,
web_content,
history_len,
temperature,
top_p,
chat_history=[]):
if web_content:
prompt_template = f"""基于以下已知信息,简洁和专业的来回答用户的问题。
如果无法从中得到答案,请说 "根据已知信息无法回答该问题" 或 "没有提供足够的相关信息",不允许在答案中添加编造成分,答案请使用中文。
已知网络检索内容:{
web_content}""" + """
已知内容:
{context}
问题:
{question}"""
else:
prompt_template = """基于以下已知信息,请简洁并专业地回答用户的问题。
如果无法从中得到答案,请说 "根据已知信息无法回答该问题" 或 "没有提供足够的相关信息"。不允许在答案中添加编造成分。另外,答案请使用中文。
已知内容:
{context}
问题:
{question}"""
prompt = PromptTemplate(template=prompt_template,
input_variables=["context", "question"])
knowledge_chain = RetrievalQA.from_llm(
llm=llm,
retriever=vector_store.as_retriever(
search_kwargs={
"k": VECTOR_SEARCH_TOP_K}),
prompt=prompt)
knowledge_chain.combine_documents_chain.document_prompt = PromptTemplate(
input_variables=["page_content"], template="{page_content}")
knowledge_chain.return_source_documents = True
result = knowledge_chain({
"query": query})
return result
def predict(self, input,
llm,
VECTOR_SEARCH_TOP_K=6,
history_len=0,
temperature=0.01,
top_p=0.9,
history=None):
if history is None:
history = []
vector_store = self.init_knowledge_vector_store()
web_content = ''
resp = self.get_knowledge_based_answer(
query=input,
llm=llm,
vector_store=vector_store,
VECTOR_SEARCH_TOP_K=VECTOR_SEARCH_TOP_K,
web_content=web_content,
chat_history=history,
history_len=history_len,
temperature=temperature,
top_p=top_p,
)
history.append((input, resp['result']))
return history
if __name__ == '__main__':
os.environ["OPENAI_API_KEY"] = "sk-xxx"
os.environ["OPENAI_API_BASE"] = "http://10.9.115.77:50000/v1"
llm = OpenAI()
DEVICE = "cpu"
l = LocalKnowledge(embedding_model_name_or_path="./abcde")
result = l.predict(input="Decoder-only 是什么", llm=llm, VECTOR_SEARCH_TOP_K=3)
print(result)
Effect
- Source of knowledge base used in the experiment: https://blog.csdn.net/xzpdxz/article/details/131358920