Python内置库：time和datetime（时间和日期）

>>> import time
>>> # time.time()方法，返回当前时间的时间戳（1970年到现在经过的浮点秒数）
>>> time.time()
1473691580.9504104
>>>  time.struct_time对象，存储时间信息
>>> structtime_obj = time.struct_time((2018,8,23,38,54,2,220,0))
>>> structtime_obj
time.struct_time(tm_year=2018,tm_mon=8,tm_mday=8,tm_hour=23,tm_min=38,tm_sec=54,tm_wday=2,tm_yday=220,tm_isdst=0)
>>> structtime_obj.tm_year
2018
>>>  time.localtime()方法，默认返回即当前时间（time.time()的int值）的struct_time对象
>>> time.localtime()
time.struct_time(tm_year=2018,tm_min=22,tm_sec=2,1)"> time.localtime(time.time())
time.struct_time(tm_year=2018,1)">0)
>>> time.localtime(80000)
time.struct_time(tm_year=1970,tm_mon=1,tm_mday=2,tm_hour=6,tm_min=13,tm_sec=20,tm_wday=4,tm_yday=2,1)">0)
>>>  time.mktime()方法，将struct_time对象转换成时间戳
>>> time.mktime(time.localtime())
1533746402.0
>>>  time.strptime()方法，将字符串按照指定格式转换为struct_time对象
>>> time.strptime('2016-09-04',%Y-%m-%d')
time.struct_time(tm_year=2016,tm_mon=9,tm_mday=4,tm_hour=0,tm_min=0,tm_sec=0,tm_wday=6,tm_yday=248,tm_isdst=-1)
>>>  time.strftime()方法，将struct_time对象转换成指定格式的字符串
>>> time.strftime(%Y-%m-%d %H:%M:%S2018-08-09 00:43:04'

>>>  datetime
>>>  now()方法，返回当期时间的datetime对象，可通过str得到日期时间信息的字符串
>>> datetime_now = datetime.datetime.now()
>>> datetime_now
datetime.datetime(2018,9,59,3,487000)
>>> str(datetime_now)
2018-08-09 00:59:03.487000'
>>>  fromtimestamp()方法，将时间戳转换成datetime对象，并返回
>>> datetime.datetime.fromtimestamp(time.time())
datetime.datetime(2018,1,51,546000 strptime()方法，将字符串按照指定格式转成datetime对象
>>> datetime.datetime.strptime()
datetime.datetime(2016,4 strftime()方法，将datetime对象转换为指定格式的字符串，并返回
>>> datetime.datetime.strftime(datetime.datetime.now(),1)">)
2018-08-09 01:18:10 timedelta对象，可用于日期时间信息的加减操作
>>> timedelta_hour = datetime.timedelta(hours=4)
>>> timedelta_day = datetime.timedelta(days=8)
>>> timedelta_new = timedelta_hour + timedelta_day
>>> timedelta_hour
datetime.timedelta(0,14400 timedelta_day
datetime.timedelta(8 timedelta_new
datetime.timedelta(8,14400 datetime.datetime.now()
datetime.datetime(2018,30,593000)
>>> datetime_new = datetime.datetime.now() + timedelta_new
>>> datetime_new
datetime.datetime(2018,17,5,70000)
>>> # timetuple()方法，将datetime对象转换成struct_time对象
>>> now_datetime = datetime.datetime.now()
>>> now_datetime.timetuple()
time.struct_time(tm_year=2018,tm_mday=9,tm_hour=2,tm_min=5,tm_sec=50,tm_wday=3,tm_yday=221,tm_isdst=-1)