DocArray HnswSearch
DocArrayHnswSearch 是一個輕量級的文件索引實作，由 Docarray 提供，完全在本機執行，最適合小型到中型的資料集。 它將向量儲存在 hnswlib 的磁碟上，並將所有其他資料儲存在 SQLite 中。
您需要安裝 langchain-community，使用 pip install -qU langchain-community 才能使用此整合
這個筆記本展示了如何使用與 DocArrayHnswSearch 相關的功能。
設定
取消註解以下儲存格以安裝 docarray 並取得/設定您的 OpenAI API 金鑰（如果您尚未這樣做）。
%pip install --upgrade --quiet "docarray[hnswlib]"
# Get an OpenAI token: https://platform.openai.com/account/api-keys
# import os
# from getpass import getpass
# OPENAI_API_KEY = getpass()
# os.environ["OPENAI_API_KEY"] = OPENAI_API_KEY
使用 DocArrayHnswSearch
from langchain_community.document_loaders import TextLoader
from langchain_community.vectorstores import DocArrayHnswSearch
from langchain_openai import OpenAIEmbeddings
from langchain_text_splitters import CharacterTextSplitter
documents = TextLoader("../../how_to/state_of_the_union.txt").load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
docs = text_splitter.split_documents(documents)
embeddings = OpenAIEmbeddings()
db = DocArrayHnswSearch.from_documents(
docs, embeddings, work_dir="hnswlib_store/", n_dim=1536
)
相似度搜尋
query = "What did the president say about Ketanji Brown Jackson"
docs = db.similarity_search(query)
print(docs[0].page_content)
Tonight. I call on the Senate to: Pass the Freedom to Vote Act. Pass the John Lewis Voting Rights Act. And while you’re at it, pass the Disclose Act so Americans can know who is funding our elections.
Tonight, I’d like to honor someone who has dedicated his life to serve this country: Justice Stephen Breyer—an Army veteran, Constitutional scholar, and retiring Justice of the United States Supreme Court. Justice Breyer, thank you for your service.
One of the most serious constitutional responsibilities a President has is nominating someone to serve on the United States Supreme Court.
And I did that 4 days ago, when I nominated Circuit Court of Appeals Judge Ketanji Brown Jackson. One of our nation’s top legal minds, who will continue Justice Breyer’s legacy of excellence.
帶有分數的相似度搜尋
返回的距離分數是餘弦距離。 因此，較低的分數較佳。
docs = db.similarity_search_with_score(query)
docs[0]
(Document(page_content='Tonight. I call on the Senate to: Pass the Freedom to Vote Act. Pass the John Lewis Voting Rights Act. And while you’re at it, pass the Disclose Act so Americans can know who is funding our elections. \n\nTonight, I’d like to honor someone who has dedicated his life to serve this country: Justice Stephen Breyer—an Army veteran, Constitutional scholar, and retiring Justice of the United States Supreme Court. Justice Breyer, thank you for your service. \n\nOne of the most serious constitutional responsibilities a President has is nominating someone to serve on the United States Supreme Court. \n\nAnd I did that 4 days ago, when I nominated Circuit Court of Appeals Judge Ketanji Brown Jackson. One of our nation’s top legal minds, who will continue Justice Breyer’s legacy of excellence.', metadata={}),
0.36962226)
import shutil
# delete the dir
shutil.rmtree("hnswlib_store")