如果您要查找确切的日期或“更精确的”日期,那么最好检查一下dateutil。
快速示例:
>>> from dateutil.relativedelta import relativedelta
>>> import datetime
>>> TODAY = datetime.date.today()
>>> TODAY
datetime.date(2012, 3, 6)
现在,向加上3个月TODAY
,观察它与当天完全匹配(请注意,relativedelta(months=3)
并且relativedelta(month=3)
行为不同。请确保使用months
这些示例!)。
>>> three_mon_rel = relativedelta(months=3)
>>> TODAY + three_mon_rel
datetime.date(2012, 6, 6)
并且在整个一年中保持一致。从字面上看,这一天是每三个月一次(必须继续添加,因为某种原因将a乘relativedelta
并将其添加到datetime.date
对象会抛出TypeError
):
>>> TODAY + three_mon_rel + three_mon_rel
datetime.date(2012, 9, 6)
>>> TODAY + three_mon_rel + three_mon_rel + three_mon_rel
datetime.date(2012, 12, 6)
>>> TODAY + three_mon_rel + three_mon_rel + three_mon_rel + three_mon_rel
datetime.date(2013, 3, 6)
而mVChr的建议解决方案虽然肯定“足够好”,但随着时间的推移会略有漂移:
>>> three_mon_timedelta = datetime.timedelta(days=3 * 365/12)
>>> TODAY + three_mon_timedelta
datetime.date(2012, 6, 5)
在一年的过程中,一个月中的某天持续下滑:
>>> TODAY + three_mon_timedelta * 2
datetime.date(2012, 9, 4)
>>> TODAY + three_mon_timedelta * 3
datetime.date(2012, 12, 4)
>>> TODAY + three_mon_timedelta * 4
datetime.date(2013, 3, 5)