offsets.py 文件源码

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

        if n > 0 and not other.day >= lastBDay:
            n = n - 1
        elif n <= 0 and other.day > lastBDay:
            n = n + 1
        other = other + relativedelta(months=n, day=31)

        if other.weekday() > 4:
            other = other - BDay()
        return other