tz.py 文件源码

def __init__(self, stdabbr, stdoffset=None,
                 dstabbr=None, dstoffset=None,
                 start=None, end=None):

        global relativedelta
        from dateutil import relativedelta

        self._std_abbr = stdabbr
        self._dst_abbr = dstabbr

        try:
            stdoffset = _total_seconds(stdoffset)
        except (TypeError, AttributeError):
            pass

        try:
            dstoffset = _total_seconds(dstoffset)
        except (TypeError, AttributeError):
            pass

        if stdoffset is not None:
            self._std_offset = datetime.timedelta(seconds=stdoffset)
        else:
            self._std_offset = ZERO

        if dstoffset is not None:
            self._dst_offset = datetime.timedelta(seconds=dstoffset)
        elif dstabbr and stdoffset is not None:
            self._dst_offset = self._std_offset + datetime.timedelta(hours=+1)
        else:
            self._dst_offset = ZERO

        if dstabbr and start is None:
            self._start_delta = relativedelta.relativedelta(
                hours=+2, month=4, day=1, weekday=relativedelta.SU(+1))
        else:
            self._start_delta = start

        if dstabbr and end is None:
            self._end_delta = relativedelta.relativedelta(
                hours=+1, month=10, day=31, weekday=relativedelta.SU(-1))
        else:
            self._end_delta = end

        self._dst_base_offset_ = self._dst_offset - self._std_offset
        self.hasdst = bool(self._start_delta)