#! /usr/bin/env python

# Given address book CSV data with display name values in the format of
# "Firstname Lastname", change to "Lastname, Firstname".

import csv, StringIO

data = '''"First Name","Last Name","Display Name"
"James","Kirk","James Kirk"
"Spock","","Spock"
"Leonard","McCoy","Leonard McCoy"'''

inf = ('First Name','Last Name','Display Name')


i = StringIO.StringIO(data)
r = csv.DictReader(i, inf)

o = StringIO.StringIO()
w = csv.DictWriter(o, inf)

def main():
	for row in r:
		if row['Display Name'] == 'Display Name':
			pass
		else:
			if len(row['Last Name']) > 0:
				s = '%s, %s' % (row['Last Name'], row['First Name'])
				row['Display Name'] = s
		w.writerow(row)
	print o.getvalue()

if __name__ == '__main__':
	main()