rdfToGeoJSON.py

#!/usr/bin/python

# Copyright (c) 2015
# Jean-Marc Montanier
# COMPUTER APPLICATIONS IN SCIENCE & ENGINEERING
# BARCELONA SUPERCOMPUTING CENTRE - CENTRO NACIONAL DE SUPERCOMPUTACION
# http://www.bsc.es
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library.  If not, see <http://www.gnu.org/licenses/>.

from rdflib import Graph
import json
import requests
from rdflib import URIRef
import sys
import urllib

if not len(sys.argv) == 3:
    print "Use of the script: ./rdfToGeoJSON.py inputFile outputFile"
    exit()

g = Graph().parse(sys.argv[1], format='n3')

output = open(sys.argv[2],"w")
output.write("""{
"type": "FeatureCollection",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },

"features": [
""")

previous = False
for s,p,o in g.triples( (None,URIRef(u'http://www.opengis.net/ont/geosparql#hasGeometry'),None)):
    geo = json.loads(g.value(o,URIRef(u'http://data.ordnancesurvey.co.uk/ontology/geometry/asGeoJSON')))
    api_url = 'http://pelagios.org/peripleo/places/' + urllib.quote_plus(s.encode("utf-8"))
    api_response = requests.get(api_url)

    parsed_json = json.loads(api_response.text)

    provinceURI = parsed_json['identifier']
    provinceName = parsed_json['title']

    geoType = geo["type"]
    geoCoord = geo["coordinates"]

    if previous == False:
        output.write('{ "type": "Feature",')
        previous = True
    else:
        output.write(',{ "type": "Feature",')

    output.write('"properties" : { "name" : "' + provinceName + '", "uri" : "' + provinceURI + '" },')
    output.write('"geometry" : { "type": "' + str(geo["type"] + '", "coordinates": ' + str(geoCoord)) + '}}')
    output.write('\n')

output.write('] }')
output.close()