Command-line script for converting MARC21 to Dublin Core XML

marc2dc.py

"""Python script for converting MARC21 to Dublin Core XML

Usage:
Command-line
$ mkdir output_xml
$ cp marc2dc.py output_xml/.
$ cd output_xml
$ python marc2dc.py --marc E:\Research\test-marc-file.mrc
"""

___author__ = "Jeremy Nelson"
__license__ = "GPLv3"

import argparse
import datetime
import pymarc
import urllib.request
from lxml import etree

MARC_DC_URL = 'http://www.loc.gov/standards/marcxml/xslt/MARC21slim2RDFDC.xsl'

class FileResolver(etree.Resolver):
    """Copied from Stackoverflow: http://stackoverflow.com/questions/8831941/lxml-and-xsl-document-function"""

    def resolve(self, url, pubid, context):
        return self.resolve_filename(url, context)

def run(marc21_file):
    """Function takes a marc21 filepath, converts each record to MARCXML,  
    run LOC MARC2DC XLST, and saves resulting DC XML to disk"""
    reader = pymarc.MARCReader(open(marc21_file, 'rb'), to_unicode=True)
    parser = etree.XMLParser()
    parser.resolvers.add(FileResolver())
    marc2dc_xslt = etree.parse(
        urllib.request.urlopen(MARC_DC_URL), parser=parser)
    transform = etree.XSLT(marc2dc_xslt)
    for i, record in enumerate(reader):
        # Convert to MARC XML
        record_xml = etree.XML(
            pymarc.record_to_xml(record, namespace=True),
            parser=parser)
        # Transform to Dublin Core RDF XML
        dc_xml = transform(record_xml)
        # Save to DC XML local directory
        if '001' in record:
            dc_filename = "dc-{}.xml".format(record['001'].data)
        else:
            dc_filename = "dc-marc-{}.xml".format(i)
        with open(dc_filename, 'w+') as dc_file:
            dc_file.write(etree.tostring(dc_xml).decode())


if __name__ == '__main__':
    arg_parser = argparse.ArgumentParser()
    arg_parser.add_argument('--marc', help='Full Path to MARC21 file')
    args = arg_parser.parse_args()
    start = datetime.datetime.utcnow()
    print("Starting MARC21 to Dublin Core at {}".format(start.isoformat()))
    run(args.marc)
    end = datetime.datetime.utcnow()
    print("Finished MARC21 to Dublin Core at {}, total time={} seconds".format(
        end.isoformat(),
        (end-start).seconds))