From 81d13d432b7e49b557b5de11691bdeaed31a9b06 Mon Sep 17 00:00:00 2001 From: Matt Goldberg <59745812+mgberg@users.noreply.github.com> Date: Tue, 11 Apr 2023 17:12:27 -0400 Subject: [PATCH] feat: add optional `target_graph` argument to `Graph.cbd` and use it for DESCRIBE queries (#2322) Add optional keyword only `target_graph` argument to `rdflib.graph.Graph.cbd` and use this new argument in `evalDescribeQuery`. This makes it possible to compute a concise bounded description without creating a new graph to hold the result, and also without potentially having to copy it to another final graph. Co-authored-by: Iwan Aucamp --- rdflib/graph.py | 12 +++++++++--- rdflib/plugins/sparql/evaluate.py | 2 +- test/test_graph/test_graph_cbd.py | 27 ++++++++++++++++++++++++++- 3 files changed, 36 insertions(+), 5 deletions(-) diff --git a/rdflib/graph.py b/rdflib/graph.py index c6f0fd36c..6e2e50aff 100644 --- a/rdflib/graph.py +++ b/rdflib/graph.py @@ -1814,7 +1814,9 @@ def do_de_skolemize2(t: _TripleType) -> _TripleType: return retval - def cbd(self, resource: _SubjectType) -> Graph: + def cbd( + self, resource: _SubjectType, *, target_graph: Optional[Graph] = None + ) -> Graph: """Retrieves the Concise Bounded Description of a Resource from a Graph Concise Bounded Description (CBD) is defined in [1] as: @@ -1840,10 +1842,14 @@ def cbd(self, resource: _SubjectType) -> Graph: [1] https://www.w3.org/Submission/CBD/ :param resource: a URIRef object, of the Resource for queried for - :return: a Graph, subgraph of self + :param target_graph: Optionally, a graph to add the CBD to; otherwise, a new graph is created for the CBD + :return: a Graph, subgraph of self if no graph was provided otherwise the provided graph """ - subgraph = Graph() + if target_graph is None: + subgraph = Graph() + else: + subgraph = target_graph def add_to_cbd(uri: _SubjectType) -> None: for s, p, o in self.triples((uri, None, None)): diff --git a/rdflib/plugins/sparql/evaluate.py b/rdflib/plugins/sparql/evaluate.py index 764250c8c..08dd02d57 100644 --- a/rdflib/plugins/sparql/evaluate.py +++ b/rdflib/plugins/sparql/evaluate.py @@ -630,7 +630,7 @@ def evalDescribeQuery(ctx: QueryContext, query) -> Dict[str, Union[str, Graph]]: # Get a CBD for all resources identified to describe for resource in to_describe: # type error: Item "None" of "Optional[Graph]" has no attribute "cbd" - graph += ctx.graph.cbd(resource) # type: ignore[union-attr] + ctx.graph.cbd(resource, target_graph=graph) # type: ignore[union-attr] res: Dict[str, Union[str, Graph]] = {} res["type_"] = "DESCRIBE" diff --git a/test/test_graph/test_graph_cbd.py b/test/test_graph/test_graph_cbd.py index 66861241a..cb9e3761b 100644 --- a/test/test_graph/test_graph_cbd.py +++ b/test/test_graph/test_graph_cbd.py @@ -4,7 +4,8 @@ import pytest from rdflib import Graph, Namespace -from rdflib.term import URIRef +from rdflib.namespace import RDF, RDFS +from rdflib.term import Literal, URIRef EXAMPLE_GRAPH_FILE_PATH = TEST_DATA_DIR / "spec" / "cbd" / "example_graph.rdf" EXAMPLE_GRAPH_CBD_FILE_PATH = TEST_DATA_DIR / "spec" / "cbd" / "example_graph_cbd.rdf" @@ -134,3 +135,27 @@ def test_cbd_example(): assert len(g.cbd(URIRef(query))) == ( 21 ), "cbd() for aReallyGreatBook should return 21 triples" + + +def test_cbd_target(rdfs_graph: Graph): + """ + `Graph.cbd` places the Concise Bounded Description in the target graph. + """ + + target = Graph() + result = rdfs_graph.cbd(RDFS.Literal, target_graph=target) + + expected_result = { + (RDFS.Literal, RDFS.subClassOf, RDFS.Resource), + (RDFS.Literal, RDF.type, RDFS.Class), + (RDFS.Literal, RDFS.label, Literal("Literal")), + ( + RDFS.Literal, + RDFS.comment, + Literal("The class of literal values, eg. textual strings and integers."), + ), + (RDFS.Literal, RDFS.isDefinedBy, URIRef(f"{RDFS}")), + } + + assert result is target + assert expected_result == set(result.triples((None, None, None)))