python获取指定日期的前n天或后n天日期

 
  
 
  
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