Python日期的加减

一、timedelta

#Python的timedelta可以处理时间的加减

import datetime
sdate  = datetime.datetime.strptime('2019.01.05','%Y.%m.%d')
delta7 = datetime.timedelta(days=7)
edate  = sdate + delta7
print(edate)    #2019-01-12 00:00:00

用上述办法分情况加30天或者31天得到下个月日期，碰到2月份还要考虑是28天还是闰年的29天，判断起来很麻烦而且还没有办法100%得到想要的数据。

二、python-dateutil模块

1、安装

pip install python-dateutil

2、日期加减

import datetime
from dateutil.relativedelta import relativedelta
sdate  = datetime.datetime.strptime('2019.01.05','%Y.%m.%d')
edate  = sdate + relativedelta(months=1)
print(edate)    #2019-02-05 00:00:00

----------------------
sdate  = datetime.datetime.strptime('2019.01.05','%Y.%m.%d')
edate  = sdate + relativedelta(years=+2, months=+8, days=+16,hours=+20, minutes=+54, seconds=+47)
print(edate)  #2021-09-21 20:54:47

备注：relativedelta函数，参数特别多，功能很强大，完美解决了获取正确日期的问题

3、官网示例

# -*- coding:utf-8 -*-
from dateutil.relativedelta import relativedelta
from dateutil.easter import easter
from dateutil.rrule import rrule,YEARLY,FR
from dateutil.parser import parse

now = parse("Wed Jan 1 17:13:46 UTC 2020")
today = now.date()
year = rrule(YEARLY,dtstart=now,bymonth=8,bymonthday=13,byweekday=FR)[0].year
rdelta = relativedelta(easter(year), today)


print("Today is: %s" % today)
print("Year with next Aug 13th on a Friday is: %s" % year)
print("How far is the Easter of that year: %s" % rdelta)
print("And the Easter of that year is: %s" % (today+rdelta))

官网地址：https://pypi.org/project/python-dateutil/