Replace bottom-coded values with null

addNullValues.py

#!/usr/bin/python
# Remove all the -99999... values in the NL neighborhoods file and replace them with NULL

from sys import argv
import fiona

with fiona.open(argv[1]) as infile:
    meta = infile.meta
    meta['schema']['geometry'] = 'MultiPolygon'

    fidx = 0

    with fiona.open(argv[2], 'w', **meta) as outfile:
        for f in infile:
            fidx += 1

            if fidx % 1000 == 0:
                print '{0} features processed'.format(fidx)

            for prop, val in f['properties'].iteritems():
                if val < -10000:
                    f['properties'][prop] = None

            outfile.write(f)