Work with PROV-O (RDF)

PROV-O support needs the optional rdflib dependency:

python -m pip install "prov[rdf]"

The serialization format is selected with format="rdf". A second, RDF-specific keyword, rdf_format, chooses the concrete RDF syntax ("trig" by default) — do not confuse the two.

Serialize to a file

import prov.model as pm

document = pm.ProvDocument()
document.set_default_namespace("http://example.org/")
e = document.entity("e1")
a = document.activity("a1")
document.wasGeneratedBy(e, a)

document.serialize("document.trig", format="rdf")  # rdf_format="trig" is the default

Choose a different RDF syntax

rdf_format accepts anything rdflib can serialize to, e.g. "turtle", "xml" (RDF/XML), "nt", "nquads":

turtle_str = document.serialize(format="rdf", rdf_format="turtle")
print(turtle_str)

Important

Only quad-based syntaxes ("trig" — the default — and "nquads") preserve bundles as separate named graphs. Triple-based syntaxes such as "turtle" or "xml" flatten every bundle’s statements into a single graph, discarding which bundle each statement came from. Stick with the default TriG if your document has bundles.

Serialize to a string

trig_str = document.serialize(format="rdf")

Deserialize from a file or stream

loaded = pm.ProvDocument.deserialize("document.trig", format="rdf")
assert loaded == document

Pass the matching rdf_format if the input is not TriG:

loaded = pm.ProvDocument.deserialize(content=turtle_str, format="rdf", rdf_format="turtle")

Deserialize from a string

loaded = pm.ProvDocument.deserialize(content=trig_str, format="rdf")

Auto-detect the format with prov.read()

PROV-O/RDF is the second format prov.read() tries (after PROV-JSON), so genuine RDF content auto-detects reliably:

import prov

loaded = prov.read("document.trig")
assert loaded == document

Common errors

Malformed RDF raises rdflib’s own parser error:

try:
    pm.ProvDocument.deserialize(content="not rdf", format="rdf")
except Exception as e:
    print(f"{type(e).__name__}")

BadSyntax