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conjunctive_graphs

An RDFLib ConjunctiveGraph is an (unnamed) aggregation of all the Named Graphs within a Store. The ConjunctiveGraph.get_context method can be used to get a particular named graph for use, such as to add triples to, or the default graph can be used.

This example shows how to create Named Graphs and work with the conjunction (union) of all the graphs.

Attributes:

LOVE module-attribute 

LOVE = Namespace('http://love.com#')

LOVERS module-attribute 

LOVERS = Namespace('http://love.com/lovers/')

cjohn module-attribute 

cjohn = URIRef('http://love.com/lovers/john')

cmary module-attribute 

cmary = URIRef('http://love.com/lovers/mary')

g module-attribute 

g = ConjunctiveGraph(store=store)

gjohn module-attribute 

gjohn = Graph(store=store, identifier=cjohn)

gmary module-attribute 

gmary = Graph(store=store, identifier=cmary)

john module-attribute 

john = URIRef('http://love.com/lovers/john')

mary module-attribute 

mary = URIRef('http://love.com/lovers/mary')

store module-attribute 

store = Memory()

xx module-attribute 

xx = x

false show_docstring_attributes: false show_docstring_functions: false show_docstring_modules: false show_docstring_classes: false show_signature: false show_signature_annotations: false show_signature_type_parameters: false show_docstring_other_parameters: false show_docstring_parameters: false show_docstring_raises: false show_docstring_receives: false show_docstring_returns: false summary: false show_if_no_docstring: false

from rdflib import Literal, Namespace, URIRef
from rdflib.graph import ConjunctiveGraph, Graph
from rdflib.plugins.stores.memory import Memory

if __name__ == "__main__":
    LOVE = Namespace("http://love.com#")
    LOVERS = Namespace("http://love.com/lovers/")

    mary = URIRef("http://love.com/lovers/mary")
    john = URIRef("http://love.com/lovers/john")

    cmary = URIRef("http://love.com/lovers/mary")
    cjohn = URIRef("http://love.com/lovers/john")

    store = Memory()

    g = ConjunctiveGraph(store=store)
    g.bind("love", LOVE)
    g.bind("lovers", LOVERS)

    # Add a graph containing Mary's facts to the Conjunctive Graph
    gmary = Graph(store=store, identifier=cmary)
    # Mary's graph only contains the URI of the person she loves, not his cute name
    gmary.add((mary, LOVE.hasName, Literal("Mary")))
    gmary.add((mary, LOVE.loves, john))

    # Add a graph containing John's facts to the Conjunctive Graph
    gjohn = Graph(store=store, identifier=cjohn)
    # John's graph contains his cute name
    gjohn.add((john, LOVE.hasCuteName, Literal("Johnny Boy")))

    # Enumerate contexts
    print("Contexts:")
    for c in g.contexts():
        print(f"-- {c.identifier} ")
    print("===================")
    # Separate graphs
    print("John's Graph:")
    print(gjohn.serialize())
    print("===================")
    print("Mary's Graph:")
    print(gmary.serialize())
    print("===================")

    print("Full Graph")
    print(g.serialize())
    print("===================")

    print("Query the conjunction of all graphs:")
    xx = None
    for x in g[mary : LOVE.loves / LOVE.hasCuteName]:  # type: ignore[misc]
        xx = x
    print("Q: Who does Mary love?")
    print("A: Mary loves {}".format(xx))