filter.py

#!/usr/bin/env python

from time import strftime, strptime, mktime

file_name       = 'names.lst'
trash_file_name = 'old_names.lst'
filter_date     = strftime('%d-%m-%Y') #'01-01-2012'

def timestamp(strtime, format = '%d-%m-%Y'):
  return mktime(strptime(strtime, format))

filter_date = timestamp(filter_date)

items = list()
trash_items = list()

with open(file_name) as fl:

	for line in fl.readlines():
		date = line.rstrip().split(' ')[-1]

		if timestamp(date) < filter_date:
			print 'Moving', line
			trash_items.append(line)
		else:
			items.append(line)

with open(file_name, 'w') as fl, open(trash_file_name, 'w') as trash_fl:
	fl.writelines(items)
	trash_fl.writelines(trash_items)