RDFLib

RDFLib 是一個純 Python 套件，用於處理 RDF。 RDFLib 包含處理 RDF 的大部分所需內容，包括

RDF/XML、N3、NTriples、N-Quads、Turtle、TriX、Trig 和 JSON-LD 的剖析器和序列化器

圖形介面，可以由多種儲存實作的任何一種支援

記憶體內、磁碟上持久性 (Berkeley DB) 和遠端 SPARQL 端點的儲存實作

SPARQL 1.1 實作 - 支援 SPARQL 1.1 查詢和更新陳述式

SPARQL 函數擴充機制

圖形資料庫是基於網路狀模型的應用程式的絕佳選擇。為了標準化此類圖形的語法和語義，W3C 建議使用 語義網技術，cp. 語義網。

SPARQL 作為這些圖形的查詢語言，類似於 SQL 或 Cypher。此筆記本示範了 LLM 作為圖形資料庫的自然語言介面的應用，透過產生 SPARQL。

免責聲明： 迄今為止，透過 LLM 產生 SPARQL 查詢仍然有點不穩定。對於會更改圖形的 UPDATE 查詢，請格外小心。

設定

我們必須安裝一個 python 函式庫

!pip install rdflib

您可以針對多個來源執行查詢，包括網路上的檔案、您在本機可用的檔案、SPARQL 端點，例如 Wikidata 和三元組儲存。

from langchain.chains import GraphSparqlQAChain
from langchain_community.graphs import RdfGraph
from langchain_openai import ChatOpenAI

API 參考：GraphSparqlQAChain | RdfGraph | ChatOpenAI

graph = RdfGraph(
    source_file="http://www.w3.org/People/Berners-Lee/card",
    standard="rdf",
    local_copy="test.ttl",
)

請注意，如果來源為唯讀，則提供 local_file 對於在本機儲存變更而言是必要的。

重新整理圖形結構描述資訊

如果資料庫的結構描述變更，您可以重新整理產生 SPARQL 查詢所需的結構描述資訊。

graph.load_schema()

graph.get_schema

In the following, each IRI is followed by the local name and optionally its description in parentheses. 
The RDF graph supports the following node types:
<http://xmlns.com/foaf/0.1/PersonalProfileDocument> (PersonalProfileDocument, None), <http://www.w3.org/ns/auth/cert#RSAPublicKey> (RSAPublicKey, None), <http://www.w3.org/2000/10/swap/pim/contact#Male> (Male, None), <http://xmlns.com/foaf/0.1/Person> (Person, None), <http://www.w3.org/2006/vcard/ns#Work> (Work, None)
The RDF graph supports the following relationships:
<http://www.w3.org/2000/01/rdf-schema#seeAlso> (seeAlso, None), <http://purl.org/dc/elements/1.1/title> (title, None), <http://xmlns.com/foaf/0.1/mbox_sha1sum> (mbox_sha1sum, None), <http://xmlns.com/foaf/0.1/maker> (maker, None), <http://www.w3.org/ns/solid/terms#oidcIssuer> (oidcIssuer, None), <http://www.w3.org/2000/10/swap/pim/contact#publicHomePage> (publicHomePage, None), <http://xmlns.com/foaf/0.1/openid> (openid, None), <http://www.w3.org/ns/pim/space#storage> (storage, None), <http://xmlns.com/foaf/0.1/name> (name, None), <http://www.w3.org/2000/10/swap/pim/contact#country> (country, None), <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> (type, None), <http://www.w3.org/ns/solid/terms#profileHighlightColor> (profileHighlightColor, None), <http://www.w3.org/ns/pim/space#preferencesFile> (preferencesFile, None), <http://www.w3.org/2000/01/rdf-schema#label> (label, None), <http://www.w3.org/ns/auth/cert#modulus> (modulus, None), <http://www.w3.org/2000/10/swap/pim/contact#participant> (participant, None), <http://www.w3.org/2000/10/swap/pim/contact#street2> (street2, None), <http://www.w3.org/2006/vcard/ns#locality> (locality, None), <http://xmlns.com/foaf/0.1/nick> (nick, None), <http://xmlns.com/foaf/0.1/homepage> (homepage, None), <http://creativecommons.org/ns#license> (license, None), <http://xmlns.com/foaf/0.1/givenname> (givenname, None), <http://www.w3.org/2006/vcard/ns#street-address> (street-address, None), <http://www.w3.org/2006/vcard/ns#postal-code> (postal-code, None), <http://www.w3.org/2000/10/swap/pim/contact#street> (street, None), <http://www.w3.org/2003/01/geo/wgs84_pos#lat> (lat, None), <http://xmlns.com/foaf/0.1/primaryTopic> (primaryTopic, None), <http://www.w3.org/2006/vcard/ns#fn> (fn, None), <http://www.w3.org/2003/01/geo/wgs84_pos#location> (location, None), <http://usefulinc.com/ns/doap#developer> (developer, None), <http://www.w3.org/2000/10/swap/pim/contact#city> (city, None), <http://www.w3.org/2006/vcard/ns#region> (region, None), <http://xmlns.com/foaf/0.1/member> (member, None), <http://www.w3.org/2003/01/geo/wgs84_pos#long> (long, None), <http://www.w3.org/2000/10/swap/pim/contact#address> (address, None), <http://xmlns.com/foaf/0.1/family_name> (family_name, None), <http://xmlns.com/foaf/0.1/account> (account, None), <http://xmlns.com/foaf/0.1/workplaceHomepage> (workplaceHomepage, None), <http://purl.org/dc/terms/title> (title, None), <http://www.w3.org/ns/solid/terms#publicTypeIndex> (publicTypeIndex, None), <http://www.w3.org/2000/10/swap/pim/contact#office> (office, None), <http://www.w3.org/2000/10/swap/pim/contact#homePage> (homePage, None), <http://xmlns.com/foaf/0.1/mbox> (mbox, None), <http://www.w3.org/2000/10/swap/pim/contact#preferredURI> (preferredURI, None), <http://www.w3.org/ns/solid/terms#profileBackgroundColor> (profileBackgroundColor, None), <http://schema.org/owns> (owns, None), <http://xmlns.com/foaf/0.1/based_near> (based_near, None), <http://www.w3.org/2006/vcard/ns#hasAddress> (hasAddress, None), <http://xmlns.com/foaf/0.1/img> (img, None), <http://www.w3.org/2000/10/swap/pim/contact#assistant> (assistant, None), <http://xmlns.com/foaf/0.1/title> (title, None), <http://www.w3.org/ns/auth/cert#key> (key, None), <http://www.w3.org/ns/ldp#inbox> (inbox, None), <http://www.w3.org/ns/solid/terms#editableProfile> (editableProfile, None), <http://www.w3.org/2000/10/swap/pim/contact#postalCode> (postalCode, None), <http://xmlns.com/foaf/0.1/weblog> (weblog, None), <http://www.w3.org/ns/auth/cert#exponent> (exponent, None), <http://rdfs.org/sioc/ns#avatar> (avatar, None)

查詢圖形

現在，您可以使用圖形 SPARQL QA 鏈來詢問有關圖形的問題。

chain = GraphSparqlQAChain.from_llm(
    ChatOpenAI(temperature=0), graph=graph, verbose=True
)

chain.run("What is Tim Berners-Lee's work homepage?")

[1m> Entering new GraphSparqlQAChain chain...[0m
Identified intent:
[32;1m[1;3mSELECT[0m
Generated SPARQL:
[32;1m[1;3mPREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT ?homepage
WHERE {
    ?person foaf:name "Tim Berners-Lee" .
    ?person foaf:workplaceHomepage ?homepage .
}[0m
Full Context:
[32;1m[1;3m[][0m

[1m> Finished chain.[0m

"Tim Berners-Lee's work homepage is http://www.w3.org/People/Berners-Lee/."

更新圖形

類似地，您可以使用自然語言更新圖形，即插入三元組。

chain.run(
    "Save that the person with the name 'Timothy Berners-Lee' has a work homepage at 'http://www.w3.org/foo/bar/'"
)

[1m> Entering new GraphSparqlQAChain chain...[0m
Identified intent:
[32;1m[1;3mUPDATE[0m
Generated SPARQL:
[32;1m[1;3mPREFIX foaf: <http://xmlns.com/foaf/0.1/>
INSERT {
    ?person foaf:workplaceHomepage <http://www.w3.org/foo/bar/> .
}
WHERE {
    ?person foaf:name "Timothy Berners-Lee" .
}[0m

[1m> Finished chain.[0m

'Successfully inserted triples into the graph.'

讓我們驗證結果

query = (
    """PREFIX foaf: <http://xmlns.com/foaf/0.1/>\n"""
    """SELECT ?hp\n"""
    """WHERE {\n"""
    """    ?person foaf:name "Timothy Berners-Lee" . \n"""
    """    ?person foaf:workplaceHomepage ?hp .\n"""
    """}"""
)
graph.query(query)

[(rdflib.term.URIRef('https://www.w3.org/'),),
 (rdflib.term.URIRef('http://www.w3.org/foo/bar/'),)]

傳回 SPARQL 查詢

您可以使用 return_sparql_query 參數從 Sparql QA 鏈傳回 SPARQL 查詢步驟

chain = GraphSparqlQAChain.from_llm(
    ChatOpenAI(temperature=0), graph=graph, verbose=True, return_sparql_query=True
)

result = chain("What is Tim Berners-Lee's work homepage?")
print(f"SPARQL query: {result['sparql_query']}")
print(f"Final answer: {result['result']}")

[1m> Entering new GraphSparqlQAChain chain...[0m
Identified intent:
[32;1m[1;3mSELECT[0m
Generated SPARQL:
[32;1m[1;3mPREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT ?workHomepage
WHERE {
    ?person foaf:name "Tim Berners-Lee" .
    ?person foaf:workplaceHomepage ?workHomepage .
}[0m
Full Context:
[32;1m[1;3m[][0m

[1m> Finished chain.[0m
SPARQL query: PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT ?workHomepage
WHERE {
    ?person foaf:name "Tim Berners-Lee" .
    ?person foaf:workplaceHomepage ?workHomepage .
}
Final answer: Tim Berners-Lee's work homepage is http://www.w3.org/People/Berners-Lee/.

print(result["sparql_query"])

PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT ?workHomepage
WHERE {
    ?person foaf:name "Tim Berners-Lee" .
    ?person foaf:workplaceHomepage ?workHomepage .
}

設定​

重新整理圖形結構描述資訊​

查詢圖形​

更新圖形​

傳回 SPARQL 查詢​

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設定

重新整理圖形結構描述資訊

查詢圖形

更新圖形

傳回 SPARQL 查詢