Auditing Uniformity

import csv
import pprint

fieldname = "wgs84_pos#lat"
minval = -90
maxval = 90

def skip_lines(input_file, skip):
	for i in range(0, skip):
		next(input_file)

def is_number(s):
	try:
		float(s)
		return True
	except ValueError:
		return False
	else:
		v = float(v)
		if not ((minval < v) and (v < maxval)):
			print "Found out of range value:", v

if __name__ == "__main__":
	input_file = csv.DictReader(open("cities3.csv"))
	skip_lines(input_file, 3)
	counts = {"nulls"; 0, "empties" : 0, "arrays" : 0}
	nrows = 0
	for row in input_file:
		audit_float_field(row[fieldname], counts)
		nrows += 1
	print "num cities:", nrows
	print "nulls:", counts['nulls']
	print "empties:", counts['empties']
	print "arrays:", counts['arrays']