python 日期计算

from datetime import timedelta,datetime
import time
tdy = datetime.today()
tdy = tdy.strftime("%Y/%m/%d")
tdy = time.strptime(tdy, "%Y/%m/%d")
tdy = datetime(tdy_str[0], tdy_str[1], tdy_str[2])
limit_t = time.strptime('2019/12/30', "%Y/%m/%d")
limit_t = datetime(limit_t[0],limit_t[1],limit_t[2])
result = limit_t - tdy
result = result.days
print('Accounts Expired after %s days' %result)