MoreAnalyzing graph dataDiffbot Graph TransformerOn this pageDiffbot Graph TransformerUse case​Text data often contain rich relationships and insights that can be useful for various analytics, recommendation engines, or knowledge management applications.Diffbot's NLP API allows for the extraction of entities, relationships, and semantic meaning from unstructured text data.By coupling Diffbot's NLP API with Neo4j, a graph database, you can create powerful, dynamic graph structures based on the information extracted from text. These graph structures are fully queryable and can be integrated into various applications.This combination allows for use cases such as:Building knowledge graphs from textual documents, websites, or social media feeds.Generating recommendations based on semantic relationships in the data.Creating advanced search features that understand the relationships between entities.Building analytics dashboards that allow users to explore the hidden relationships in data.Overview​LangChain provides tools to interact with Graph Databases:Construct knowledge graphs from text using graph transformer and store integrations Query a graph database using chains for query creation and executionInteract with a graph database using agents for robust and flexible querying Quickstart​First, get required packages and set environment variables:pip install langchain langchain-experimental openai neo4j wikipediaDiffbot NLP Service​Diffbot's NLP service is a tool for extracting entities, relationships, and semantic context from unstructured text data.
This extracted information can be used to construct a knowledge graph.
To use their service, you'll need to obtain an API key from Diffbot.from langchain_experimental.graph_transformers.diffbot import DiffbotGraphTransformerdiffbot_api_key = "DIFFBOT_API_KEY"diffbot_nlp = DiffbotGraphTransformer(diffbot_api_key=diffbot_api_key)This code fetches Wikipedia articles about "Warren Buffett" and then uses DiffbotGraphTransformer to extract entities and relationships.
The DiffbotGraphTransformer outputs a structured data GraphDocument, which can be used to populate a graph database.
Note that text chunking is avoided due to Diffbot's character limit per API request.from langchain.document_loaders import WikipediaLoaderquery = "Warren Buffett"raw_documents = WikipediaLoader(query=query).load()graph_documents = diffbot_nlp.convert_to_graph_documents(raw_documents)Loading the data into a knowledge graph​You will need to have a running Neo4j instance. One option is to create a free Neo4j database instance in their Aura cloud service. You can also run the database locally using the Neo4j Desktop application, or running a docker container. You can run a local docker container by running the executing the following script:docker run \    --name neo4j \    -p 7474:7474 -p 7687:7687 \    -d \    -e NEO4J_AUTH=neo4j/pleaseletmein \    -e NEO4J_PLUGINS=\[\"apoc\"\]  \    neo4j:latestIf you are using the docker container, you need to wait a couple of second for the database to start.from langchain.graphs import Neo4jGraphurl="bolt://localhost:7687"username="neo4j"password="pleaseletmein"graph = Neo4jGraph(    url=url,    username=username,     password=password)The GraphDocuments can be loaded into a knowledge graph using the add_graph_documents method.graph.add_graph_documents(graph_documents)Refresh graph schema information​If the schema of database changes, you can refresh the schema information needed to generate Cypher statementsgraph.refresh_schema()Querying the graph​We can now use the graph cypher QA chain to ask question of the graph. It is advisable to use gpt-4 to construct Cypher queries to get the best experience.from langchain.chains import GraphCypherQAChainfrom langchain.chat_models import ChatOpenAIchain = GraphCypherQAChain.from_llm(    cypher_llm=ChatOpenAI(temperature=0, model_name="gpt-4"),    qa_llm=ChatOpenAI(temperature=0, model_name="gpt-3.5-turbo"),    graph=graph, verbose=True,    )chain.run("Which university did Warren Buffett attend?")            > Entering new GraphCypherQAChain chain...    Generated Cypher:    MATCH (p:Person {name: "Warren Buffett"})-[:EDUCATED_AT]->(o:Organization)    RETURN o.name    Full Context:    [{'o.name': 'New York Institute of Finance'}, {'o.name': 'Alice Deal Junior High School'}, {'o.name': 'Woodrow Wilson High School'}, {'o.name': 'University of Nebraska'}]        > Finished chain.    'Warren Buffett attended the University of Nebraska.'chain.run("Who is or was working at Berkshire Hathaway?")            > Entering new GraphCypherQAChain chain...    Generated Cypher:    MATCH (p:Person)-[r:EMPLOYEE_OR_MEMBER_OF]->(o:Organization) WHERE o.name = 'Berkshire Hathaway' RETURN p.name    Full Context:    [{'p.name': 'Charlie Munger'}, {'p.name': 'Oliver Chace'}, {'p.name': 'Howard Buffett'}, {'p.name': 'Howard'}, {'p.name': 'Susan Buffett'}, {'p.name': 'Warren Buffett'}]        > Finished chain.    'Charlie Munger, Oliver Chace, Howard Buffett, Susan Buffett, and Warren Buffett are or were working at Berkshire Hathaway.'PreviousAnalyzing graph dataNextArangoDB QA chainUse caseOverviewQuickstartDiffbot NLP ServiceLoading the data into a knowledge graphRefresh graph schema informationQuerying the graph