DELPH-IN formats in RDF

DELPHIN-RDF is a plugin for pydelphin for representing textual based semantics as RDF graphs. Here we discuss how DELPH-IN formats can be represented in RDF. This can be considered a continuation of some discussion started here.

The pydelphin and rdflib libraries are required.

Features

DELPHIN-RDF presents the following dependencies:

• delphin.rdf: the main module responsible for mrs/eds/dmrs parsing to RDF.
• delphin.cli: pydelphin standard cli path. Here are modules describing the delphin subcommand. See delphin.cli

Besides that, in tests there are use examples. In doc there are some references. In vocabularies there is the modelling of the semantic representations in RDF.

Command Line Interface

All the modules in this package can be imported and used as a Python module, but DELPHIN-RDF declares profile-to-rdf, a delphin subcommand of the PyDelphin CLI. This subcommand requires the path to the profile to serialize as argument. There are optional arguments, such as the format of the output (-f), the representation to serialize (--to), the prefix of the URIs in the RDF (-p) and the name of the output file (-o).

Python module

To use the function of the transformation as a Python module, it's only needed to import delphin.rdf, which exports three main functions: mrs_to_rdf, dmrs_to_rdf and eds_to_rdf. They operate on a ConjunctiveGraph RDFLib object, creating named graphs for each instance in the context of this conjunctive graph, which is the graph that has all quads of a specific store. For example, to serialize a profile to DMRS-RDF, we can do

import delphin.rdf as drdf
from delphin import itsdb, tsql
from delphin.dmrs import from_mrs as dmrs_from_mrs
from delphin.codecs.simpledmrs import decode
from rdflib.graph import Graph, ConjunctiveGraph
from rdflib import URIRef, Namespace, Literal RDF, RDFS

path_to_profile = "./erg/trunk/tsdb/gold/mrs"
ts = itsdb.TestSuite(path_to_profile)
defaultGraph = ConjunctiveGraph()
ERG = Namespace("http://www.delph-in.net/schema/erg#")
DELPH = Namespace("http://www.delph-in.net/schema/")
POS = Namespace("http://www.delph-in.net/schema/pos#")
DMRS = Namespace("http://www.delph-in.net/schema/dmrs#")
defaultGraph.bind("erg", ERG)
defaultGraph.bind("delph", DELPH)
defaultGraph.bind("pos", POS)
defaultGraph.bind("dmrs", DMRS)
prefix = "http://example.com"
PROFILE = URIRef(prefix)
defaultGraph.add((PROFILE, RDF.type, DELPH.Profile))

for (parse_id, result_id, text, mrs_string) in tsql.select('parse-id result-id i-input mrs', ts):
  obj = dmrs_from_mrs(decode(mrs_string))
  ITEM = URIRef(f"{prefix}/{parse_id}")
  RESULT = URIRef(f"{prefix}/{parse_id}/{result_id}")
  DMRSI = URIRef(f"{prefix}/{parse_id}/{result_id}/dmrs")
        
  defaultGraph.add((ITEM, RDF.type, DELPH.Item))
  defaultGraph.add((RESULT, RDF.type, DELPH.Result))
  defaultGraph.add((MRSI, RDF.type, DMRS.DMRS))
        
  defaultGraph.add((ITEM, DELPH.hasText, Literal(text)))
        
  defaultGraph.add((PROFILE, DELPH.hasItem, ITEM))
  defaultGraph.add((ITEM, DELPH.hasResult, RESULT))
  defaultGraph.add((RESULT, DELPH.hasDMRS, DMRSI))

  drdf.dmrs_to_rdf(dmrs_from_mrs(simplemrs.decode(mrs_string)), 
                   DMRSI, 
                   defaultGraph) #inplace, change defaultGraph
                          
defaultGraph.serialize("./dmrs-erg-gold.nq", format="nquads")

Development

One may be able to install delphin-rdf in developer mode cloning this repo and running

$ pip install -e /path/to/delphin-rdf

You're able to remove the package simply by running

$ pip uninstall delphin-rdf

It's advised to install it using a python virtual environment.