#coding=utf-8
import time
import datetime

print time.ctime()        //打印当前时间

now_time = datetime.datetime.now()       //返回的是本地时区的当前时间
print now_time

yesterday = now_time + datetime.timedelta(days = -1)    //昨天的现在
print yesterday

now_old = now_time + datetime.timedelta(seconds = -1)    //现在的前一秒
print now_old