011_python常用查询

一、获取指定日期的后（前）一（n）天

# coding=utf-8
import datetime

#获取今天日期(年-月-日)
today = datetime.date.today()
#<1>计算今天的前n天
n = 20
beforeday = today - datetime.timedelta(days=n)
print(beforeday)     #2018-06-23


#<2>计算某天的后多少天
sometime = datetime.datetime(2018,5,4)
plustime = datetime.timedelta(days=20)   #hours=10
print(sometime + plustime)  #2018-05-24 00:00:00


#<3>计算今天和某天的时间差
endtime = datetime.datetime.now()
starttime = datetime.datetime(2018,5,4)
print((endtime - starttime).days)    #70
print((endtime - starttime).seconds)