idatetime.py 文件源码

def utcoffset(dt):
        """Return offset of local time from UTC, in minutes east of UTC.

        If local time is west of UTC, this should be negative.
        Note that this is intended to be the total offset from UTC;
        for example, if a tzinfo object represents both time zone and DST
        adjustments, utcoffset() should return their sum. If the UTC offset
        isn't known, return None. Else the value returned must be a timedelta
        object specifying a whole number of minutes in the range -1439 to 1439
        inclusive (1440 = 24*60; the magnitude of the offset must be less
        than one day).
        """