python to key is the dict sorting method of time

As shown below:

import time


def date_compare(item1, item2):
 t1 = time.mktime(time.strptime(item1, '%Y/%m/%d'))
 t2 = time.mktime(time.strptime(item2, '%Y/%m/%d'))
 print(t1, t2)
 if t1 < t2:
  return -1
 elif t1 > t2:
  return 1
 else:
  return 0

if __name__ == '__main__':

 d = {'2016/08/17': 'qqq', '2016/08/19': 'qqq', '2016/08/16': 'qqq', '2016/11/15': 'qqq', 
 '2016/08/12': 'qqq','2016/08/19': 'qqq'}
 keys = d.keys()
 q = sorted(keys, date_compare)
 print(keys)