python 日期加减与转换为str

from datetime import datetime, timedelta

now_time = datetime.now()  # datetime.datetime(2015, 10, 22, 16, 56, 51, 924895)

 str_now = str(now_time).split('.')[0]

date_last_time = datetime.strptime(last_pull_time,'%Y-%m-%d %H:%M:%S')

datetime转time时间戳：

time.mktime(order[4].timetuple())