我正在使用datetime Python模块。我希望从当前日期计算6个月的日期。有人能帮我一下吗?
我想从当前日期生成一个6个月后的日期的原因是为了生成一个回顾日期。如果用户在系统中输入数据,系统将有从输入数据之日起6个月的审查日期。
我正在使用datetime Python模块。我希望从当前日期计算6个月的日期。有人能帮我一下吗?
我想从当前日期生成一个6个月后的日期的原因是为了生成一个回顾日期。如果用户在系统中输入数据,系统将有从输入数据之日起6个月的审查日期。
当前回答
使用Python标准库,即没有dateutil或其他,并解决“2月31日”问题:
import datetime
import calendar
def add_months(date, months):
months_count = date.month + months
# Calculate the year
year = date.year + int(months_count / 12)
# Calculate the month
month = (months_count % 12)
if month == 0:
month = 12
# Calculate the day
day = date.day
last_day_of_month = calendar.monthrange(year, month)[1]
if day > last_day_of_month:
day = last_day_of_month
new_date = datetime.date(year, month, day)
return new_date
测试:
>>>date = datetime.date(2018, 11, 30)
>>>print(date, add_months(date, 3))
(datetime.date(2018, 11, 30), datetime.date(2019, 2, 28))
>>>print(date, add_months(date, 14))
(datetime.date(2018, 12, 31), datetime.date(2020, 2, 29))
其他回答
我是这样解决这个问题的:
import calendar
from datetime import datetime
moths2add = 6
now = datetime.now()
current_year = now.year
current_month = now.month
#count days in months you want to add using calendar module
days = sum(
[calendar.monthrange(current_year, elem)[1] for elem in range(current_month, current_month + moths)]
)
print now + days
使用Python 3。X你可以这样做:
from datetime import datetime, timedelta
from dateutil.relativedelta import *
date = datetime.now()
print(date)
# 2018-09-24 13:24:04.007620
date = date + relativedelta(months=+6)
print(date)
# 2019-03-24 13:24:04.007620
但是你需要安装python-dateutil模块:
pip install python-dateutil
这里有一个dateutil的例子。relativedelta,我发现它对于迭代过去一年很有用,每次跳过一个月到现在的日期:
>>> import datetime
>>> from dateutil.relativedelta import relativedelta
>>> today = datetime.datetime.today()
>>> month_count = 0
>>> while month_count < 12:
... day = today - relativedelta(months=month_count)
... print day
... month_count += 1
...
2010-07-07 10:51:45.187968
2010-06-07 10:51:45.187968
2010-05-07 10:51:45.187968
2010-04-07 10:51:45.187968
2010-03-07 10:51:45.187968
2010-02-07 10:51:45.187968
2010-01-07 10:51:45.187968
2009-12-07 10:51:45.187968
2009-11-07 10:51:45.187968
2009-10-07 10:51:45.187968
2009-09-07 10:51:45.187968
2009-08-07 10:51:45.187968
和其他答案一样,你必须弄清楚你说的“6个月后”到底是什么意思。如果你的意思是“六年后某个月的今天”,那么这个是:
datetime.datetime.now() + relativedelta(months=6)
我找不到这个问题的确切解决方案,所以我将发布我的解决方案,以防使用标准日历和datetime库可能有任何帮助。这适用于添加和减去月份,并考虑月末滚动和最后一个月比第一个月天数少的情况。如果你正在寻找更复杂的操作,我还有一个更通用的解决方案,它添加了定期间隔(天,月,年,季度,学期等),如:“1m”,“-9m”,“-1.5y”,“-3q”,“1s”等。
from datetime import datetime
from calendar import monthrange
def date_bump_months(start_date, months):
"""
bumps months back and forth.
--> if initial date is end-of-month, i will move to corresponding month-end
--> ir inital date.day is greater than end of month of final date, it casts it to momth-end
"""
signbit = -1 if months < 0 else 1
d_year, d_month = divmod(abs(months),12)
end_year = start_date.year + d_year*signbit
end_month = 0
if signbit ==-1:
if d_month < start_date.month:
end_month = start_date.month - d_month
else:
end_year -=1
end_month = 12 - (d_month - start_date.month)
else:
end_month +=start_date.month
if end_month > 12:
end_year +=1
end_month -=12
# check if we are running end-of-month dates
eom_run = monthrange(start_date.year, start_date.month)[1]==start_date.day
eom_month = monthrange((end_year), (end_month))[1]
if eom_run:
end_day = eom_month
else:
end_day = min(start_date.day, eom_month )
return date(end_year, end_month, end_day)
只需使用timetuple方法提取月份,添加您的月份并构建一个新的dateobject。如果有一个已经存在的方法,我不知道它。
import datetime
def in_the_future(months=1):
year, month, day = datetime.date.today().timetuple()[:3]
new_month = month + months
return datetime.date(year + (new_month / 12), (new_month % 12) or 12, day)
这个API有点笨拙,但可以作为示例使用。这显然也不适用于像2008-01-31 + 1个月这样的极端情况。:)