a quick filter to get rid of null entries in the world cities db

worldcitiesfilter.py

'''
filter out all the null population entries from the world cites database http://www.maxmind.com/app/worldcities
'''
import csv
with open('worldcitiespop.txt') as fh:
    reader = csv.DictReader(fh)
    cities_pop = [line for line in reader if line['Population']]

#print all the cities in the UK with a population above 200,000
print '\n'.join(['{0}: {1}'.format(entry['City'], entry['Population']) for entry in cities_pop if entry['Country']=='gb' and int(entry['Population']) > 200000])