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DocArrayInMemorySearchDocarray 提供的文档索引,将文档存储在内存中。它非常适合作为小型数据集的起点,无需启动数据库服务器。
本 notebook 展示如何使用与 DocArrayInMemorySearch 相关的功能。

设置

如果尚未安装 docarray 并设置 OpenAI API 密钥,请取消注释以下单元格进行安装和设置。
pip install -qU  langchain-community "docarray"
# 获取 OpenAI 令牌: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

返回的距离分数为余弦距离,分数越低表示越相似。
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)