pymarc dump from invenio

#!/usr/bin/env python

import sys
import traceback
from optparse import OptionParser
from pymarc import Field, Record, MARCWriter
from invenio.search_engine import perform_request_search, get_record

# these go in the 07 position
# see http://www.loc.gov/marc/bibliographic/bdleader.html
types = {
    'BOOK': 'm',
    'ARTICLE': 's',
    'ABSTRACT': 's',
    'PROPOSAL': 'm',
    'INPROCEEDINGS': 'm',
    'INCOLLECTION': 'm',
    'PHDTHESIS': 'm',
    'TECHREPORT': 'm',
    'CATALOG': 'm',
    'MISC': 'm'
}

def marc_record(id):
    data = get_record(id)
    rec = Record()
    for tag, fields in data.items():

        # control number handled below
        if tag == '001': 
            continue 

        for subfields, ind1, ind2, dunno, order in fields:
            f = Field(tag=tag, indicators=[ind1, ind2])
            for code, value in subfields:
                f.add_subfield(code, value.decode('utf-8'))
            rec.add_field(f)

    rec.add_field(Field('001', data=data['001'][0][3]))

    # deconstruct the existing leader
    l = list(rec.leader)

    # record status
    l[5] = 'n'

    # record type
    l[6] = 'a'

    # media type
    try:
        l[7] = types[data['690'][0][0][0][1]]
    except:
        print >>sys.stderr, "Got unknown media type from record %d: %s" % (id, data['690'][0][0][0][1])
        l[7] = 's'

    # encoding, assume unicode
    l[9] = 'a'

    rec.leader = ''.join(l)
    return rec

def main(opts, record_ids=[]):
    if opts.out:
        writer = MARCWriter(open(opts.out, 'w'))
    else:
        writer = MARCWriter(sys.stdout)

    if opts.query:
        query_results = perform_request_search(p=opts.query, of='id')
        record_ids.extend(query_results)

    for id in record_ids[:opts.limit]:
        try:
            rec = marc_record(id)
            writer.write(rec)
        except Exception, e:
            print "caught exception processing record %i" % id
            traceback.print_exc()

if __name__ == '__main__':
    op = OptionParser()
    op.add_option('--debug', dest='debug', action='store_true',
        help='include debugging info in log output', default=False)
    op.add_option('--limit', dest='limit', action='store',
        help='only process this many items', default=None, type=int)
    op.add_option('--query', dest='query', action='store',
        help='get record ids via query', default=0, type=str)
    op.add_option('--out', dest='out', action='store',
        help='output destination')
    opts, record_ids = op.parse_args()
    main(opts, record_ids)