Adding a value as a list to the graph about rdflib

[ashleysommer]

@mohmehmo
Another name for a RDF "list" is a Collection.
See the docs for RDF Collection here: https://rdflib.readthedocs.io/en/stable/apidocs/rdflib.html#rdflib.graph.Graph.collection

See this example for how to use it:

g = rdflib.Graph()
my_list = g.collection(rdflib.URIRef("http://example.org/my_list"))
my_list.append(rdflib.URIRef("http://example.org/Huey"))
my_list.append(rdflib.URIRef("http://example.org/Dewey"))
my_list.append(rdflib.URIRef("http://example.org/Louie"))
g.add((URIRef("http://example.org/Donald"), URIRef("http://example.org/nephews"), my_list.uri))

n3_graph = g.serialize(format="n3")

[ashleysommer]

Hi @mohmehmo
I've tested your snippet above. In this case, the object in your triple should be myList or c.uri, both work.

from rdflib import Graph, BNode, Literal, URIRef
from rdflib.collection import Collection

myList = BNode()
g = Graph()
c = Collection(g, myList)
for item in [1, 2, 3, 4, 5]:
  c.append(Literal(item))

g.add((URIRef("http://example.org/"),URIRef("http://example.org/my_list"), myList))

# Test it:
print(g.serialize(format="turtle"))

or

from rdflib import Graph, BNode, Literal, URIRef
from rdflib.collection import Collection

myList = BNode()
g = Graph()
c = Collection(g, myList)
for item in [1, 2, 3, 4, 5]:
  c.append(Literal(item))

g.add((URIRef("http://example.org/"),URIRef("http://example.org/my_list"), c.uri))

# Test it:
print(g.serialize(format="turtle"))

[mohmehmo]

@ashleysommer
Thanks for your response. Your suggestion resolved a part of my problem. Consider I have the following script to create a list as a Collection.

myList= BNode()
g = Graph('Memory')
c = Collection(g, myList)
for item in [1, 2, 3, 4, 5]:
  c.append(Literal(item))

When I want to add c as an object of (S, P, O) to the main graph, I faced with an error saying "<object> must be an rdflib term". I have tried different approaches e.g. URIRef(c), c.uri, c.n3(), but none of them works without error.
Do you have any suggestions for resolving this issue?

[mohmehmo]

@ashleysommer
Thanks a lot for your support. it is fine now.