Link documents with common named entities using GLiNER_.
GLiNER_ is a Named Entity Recognition (NER) model capable of identifying any
entity type using a bidirectional transformer encoder (BERT-like).
The GLiNERLinkExtractor uses GLiNER to create links between documents that
have named entities in common.
Example::
extractor = GLiNERLinkExtractor(
labels=["Person", "Award", "Date", "Competitions", "Teams"]
)
results = extractor.extract_one("some long text...")
.. _GLiNER: https://github.com/urchade/GLiNER
.. seealso::
- :mod:`How to use a graph vector store <langchain_community.graph_vectorstores>`
- :class:`How to create links between documents <langchain_community.graph_vectorstores.links.Link>`
Install the gliner package:
.. code-block:: bash
pip install -q langchain_community gliner
We load the state_of_the_union.txt file, chunk it, then for each chunk we
extract named entity links and add them to the chunk.
Using extract_one() ^^^^^^^^^^^^^^^^^^^
We can use :meth:extract_one on a document to get the links and add the links
to the document metadata with
:meth:~langchain_community.graph_vectorstores.links.add_links::
from langchain_community.document_loaders import TextLoader
from langchain_community.graph_vectorstores import CassandraGraphVectorStore
from langchain_community.graph_vectorstores.extractors import GLiNERLinkExtractor
from langchain_community.graph_vectorstores.links import add_links
from langchain_text_splitters import CharacterTextSplitter
loader = TextLoader("state_of_the_union.txt")
raw_documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
documents = text_splitter.split_documents(raw_documents)
ner_extractor = GLiNERLinkExtractor(["Person", "Topic"])
for document in documents:
links = ner_extractor.extract_one(document)
add_links(document, links)
print(documents[0].metadata)
.. code-block:: output
{'source': 'state_of_the_union.txt', 'links': [Link(kind='entity:Person', direction='bidir', tag='President Zelenskyy'), Link(kind='entity:Person', direction='bidir', tag='Vladimir Putin')]}
Using LinkExtractorTransformer ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Using the :class:~langchain_community.graph_vectorstores.extractors.link_extractor_transformer.LinkExtractorTransformer,
we can simplify the link extraction::
from langchain_community.document_loaders import TextLoader
from langchain_community.graph_vectorstores.extractors import (
GLiNERLinkExtractor,
LinkExtractorTransformer,
)
from langchain_text_splitters import CharacterTextSplitter
loader = TextLoader("state_of_the_union.txt")
raw_documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
documents = text_splitter.split_documents(raw_documents)
ner_extractor = GLiNERLinkExtractor(["Person", "Topic"])
transformer = LinkExtractorTransformer([ner_extractor])
documents = transformer.transform_documents(documents)
print(documents[0].metadata)
.. code-block:: output
{'source': 'state_of_the_union.txt', 'links': [Link(kind='entity:Person', direction='bidir', tag='President Zelenskyy'), Link(kind='entity:Person', direction='bidir', tag='Vladimir Putin')]}
The documents with named entity links can then be added to a :class:~langchain_community.graph_vectorstores.base.GraphVectorStore::
from langchain_community.graph_vectorstores import CassandraGraphVectorStore
store = CassandraGraphVectorStore.from_documents(documents=documents, embedding=...)
Interface for extracting links (incoming, outgoing, bidirectional).
DocumentTransformer for applying one or more LinkExtractors.