>>> import time
>>> time.time()  #返回unix时间戳
1478183199.0
>>> time.localtime()
time.struct_time(tm_year=2016, tm_mon=11, tm_mday=3, tm_hour=22, tm_min=26, tm_sec=39, tm_wday=3, tm_yday=308, tm_isdst=0)    #时间元组
>>> time.mktime(datetime.datetime(2016,11,3,22,26,39).timetuple())  #将时间元组转换为unix时间戳
1478183199.0
>>> time.sleep(1.6)  #延时，可以是小数

>>> import datetime
>>> datetime.datetime.now()  #当前tz区datetime对象
datetime.datetime(2016, 11, 03, 21, 10, 16, 302660)
>>> datetime.datetime.today()  #当前本地datetime对象
datetime.datetime(2016, 11, 03, 21, 10, 16, 302660)
>>> datetime.datetime.fromtimestamp(1478183199.0)  #根据时间戳创建datetime对象
datetime.datetime(2016, 11, 3, 22, 26, 39)
>>> dt = datetime.datetime.now()  #创建一个datetime实例
>>> dt.ctime()  #返回一个c时间格式字符串
'Thu Nov  3 22:26:39 2016'
>>> dt2 = datetime.datetime(1999, 1, 1, 0, 0)
>>> td = dt - dt2
>>> td
datetime.timedelta(6516, 80799)  #(天,秒)
>>> td.days
>>> td.seconds
>>> td.microseconds
>>> dt.strftime("%Y-%m")  #见附表
'2016-11'