from datetime import datetime, timezone, timedelta
import time
EPOCH = datetime(1970, 1, 1)
def localtime(utctime=None):
    if utctime is None:
        tm = time.localtime()
    else:
        seconds = (utctime - EPOCH).total_seconds()
        tm = time.localtime(seconds)
    
    tz = (timezone(timedelta(seconds=-time.altzone), time.tzname[1])
          if tm.tm_isdst else
          timezone(timedelta(seconds=-time.timezone), time.tzname[0]))
    return datetime(*tm[:6], tzinfo=tz)

if __name__ == '__main__':
    for t in [localtime(), localtime(datetime.utcnow()),
              localtime(datetime.utcfromtimestamp(0))]:
        print(t.tzname(), t, t.timetuple().tm_isdst)