DocArray 内存搜索
DocArrayInMemorySearch 是由 Docarray 提供的文档索引，它将文档存储在内存中。对于小型数据集来说，这是一个很好的起点，在这种情况下，你可能不想启动数据库服务器。
此笔记本展示了如何使用与 DocArrayInMemorySearch 相关的功能。
设置
如果你还没有安装 docarray 或获取/设置你的 OpenAI api 密钥，请取消注释以下单元格。
%pip install --upgrade --quiet langchain-community "docarray"
# 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 DocArrayInMemorySearch
from langchain_community.document_loaders import TextLoader
from langchain_community.vectorstores import DocArrayInMemorySearch
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 = DocArrayInMemorySearch.from_documents(docs, embeddings)
相似度搜索
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.
带分数的相似度搜索
返回的距离分数是余弦距离。因此，分数越低越好。
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={}),
0.8154190158347903)