offsets.py 文件源码

def apply(self, other):
        n = self.n
        base = other
        other = datetime(other.year, other.month, other.day,
                         other.hour, other.minute, other.second,
                         other.microsecond)

        wkday, days_in_month = tslib.monthrange(other.year, other.month)
        lastBDay = days_in_month - max(((wkday + days_in_month - 1)
                                        % 7) - 4, 0)

        monthsToGo = 3 - ((other.month - self.startingMonth) % 3)
        if monthsToGo == 3:
            monthsToGo = 0

        if n > 0 and not (other.day >= lastBDay and monthsToGo == 0):
            n = n - 1
        elif n <= 0 and other.day > lastBDay and monthsToGo == 0:
            n = n + 1

        other = other + relativedelta(months=monthsToGo + 3 * n, day=31)
        other = tslib._localize_pydatetime(other, base.tzinfo)
        if other.weekday() > 4:
            other = other - BDay()
        return other