import pytz
 import datetime

 date_format = '%Y-%m-%d %H:%M:%S'
 dt = datetime.datetime.strptime('2018-12-12 00:00:00', date_format)
 utc_tz = pytz.timezone('UTC')
 utc_d = utc_tz.localize(dt)
 teh_tz = pytz.timezone('Asia/Tehran')
 dt = utc_d.astimezone(teh_tz)