python获取指定日期的前n天或后n天日期

<pre name="code" class="plain">

首先导入time，和datetime包

import datetime
import time

实现代码如下：

if __name__ == '__main__':
        dt=sys.argv[1]
        myday = datetime.datetime( int(dt[0:4]),int(dt[5:7]),int(dt[8:10]) ) + datetime.timedelta(days=-1)
        dt = myday.strftime('%Y-%m-%d')
        timestamp = int(time.mktime(time.strptime(dt, "%Y-%m-%d")))
        print dt
        datetime.timedelta()
        now_time = datetime.datetime.now()
        yes_time = now_time + datetime.timedelta(days=-2)
        # yes_time_nyr = last_time.strftime('%Y%m%d')
        print now_time
        print yes_time
        print yes_time.strftime('%Y-%m-%d')

运行命令： python test.py 2015-04-01

输出结果：

2015-03-31

2015-04-01 10:46:28.099195

2015-03-30 10:46:28.099195

2015-03-30