17. Python时间和日期操作¶
目录
Python时间和日期操作，总是容易搞混淆，现在对相关库的用法坐下总结！
17.1. 相关对象¶
>>> import time
>>>
>>>
>>> time.localtime()
time.struct_time(tm_year=2017, tm_mon=6, tm_mday=13, tm_hour=23, tm_min=20, tm_sec=48, tm_wday=1, tm_yday=164, tm_isdst=1)
>>>
>>>
>>> time.strptime("2017-5-3",'%Y-%m-%d')
time.struct_time(tm_year=2017, tm_mon=5, tm_mday=3, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=2, tm_yday=123, tm_isdst=-1)
>>>
>>> time.strptime("2017-5-3 13:20:5",'%Y-%m-%d %H:%M:%S')
time.struct_time(tm_year=2017, tm_mon=5, tm_mday=3, tm_hour=13, tm_min=20, tm_sec=5, tm_wday=2, tm_yday=123, tm_isdst=-1)
>>> import datetime
>>> now = datetime.datetime.now()
>>> now
datetime.datetime(2017, 6, 13, 23, 27, 41, 421889)
>>>
>>> t = datetime.datetime(2017, 5, 13, 21, 12, 43)
>>>
>>> t
datetime.datetime(2017, 5, 13, 21, 12, 43)
>>>
>>> t.strftime("%Y-%m-%d %H:%M:%S")
'2017-05-13 21:12:43'
17.2. 转化关系¶
17.2.1. tuple <–> string¶
>>> ttu = time.strptime("2017-5-3 13:20:5",'%Y-%m-%d %H:%M:%S')
>>>
>>> ttu
time.struct_time(tm_year=2017, tm_mon=5, tm_mday=3, tm_hour=13, tm_min=20, tm_sec=5, tm_wday=2, tm_yday=123, tm_isdst=-1)
>>> time.strftime("%Y-%m-%d %H:%M", ttu)
'2017-05-03 13:20'
>>>
>>> time.strptime("2017-5-3 13:20:5",'%Y-%m-%d %H:%M:%S')
time.struct_time(tm_year=2017, tm_mon=5, tm_mday=3, tm_hour=13, tm_min=20, tm_sec=5, tm_wday=2, tm_yday=123, tm_isdst=-1)
17.2.2. datetime <–> string¶
>>> t = datetime.datetime(2017, 5, 13, 21, 12, 43)
>>>
>>> t
datetime.datetime(2017, 5, 13, 21, 12, 43)
>>>
>>> t.strftime("%Y-%m-%d %H:%M:%S")
'2017-05-13 21:12:43'
>>>
>>> datetime.datetime.strptime("2014-12-31 18:20:10", "%Y-%m-%d %H:%M:%S")
datetime.datetime(2014, 12, 31, 18, 20, 10)
17.2.3. datetime <–> timetuple¶
>>> now = datetime.datetime.now()
>>> now
datetime.datetime(2017, 6, 13, 23, 53, 10, 530091)
>>>
>>> now.timetuple()
time.struct_time(tm_year=2017, tm_mon=6, tm_mday=13, tm_hour=23, tm_min=53, tm_sec=10, tm_wday=1, tm_yday=164, tm_isdst=-1)
>>>
>>> ntu = now.timetuple()
>>>
>>> ntu
time.struct_time(tm_year=2017, tm_mon=6, tm_mday=13, tm_hour=23, tm_min=53, tm_sec=10, tm_wday=1, tm_yday=164, tm_isdst=-1)
而timetuple转化为datetime，可以先转化为timestamp。
>>> ntu
time.struct_time(tm_year=2017, tm_mon=6, tm_mday=13, tm_hour=23, tm_min=53, tm_sec=10, tm_wday=1, tm_yday=164, tm_isdst=-1)
>>>
>>> ts = time.mktime(ntu)
>>>
>>> ts
1497423190.0
>>>
>>> datetime.datetime.fromtimestamp(ts)
datetime.datetime(2017, 6, 13, 23, 53, 10)
17.2.4. 时间戳转换成成string¶
两种方法：
>>> ts
1497423190.0
>>>
>>> time.ctime(ts)
'Tue Jun 13 23:53:10 2017'
>>>
>>> import datetime
>>> datetime.datetime.fromtimestamp(ts).strftime("%Y-%m-%d %H:%M:%S")
'2017-06-13 23:53:10'
17.2.5. 其他转化¶
>>> ts
1497423190.0
>>> ntu
time.struct_time(tm_year=2017, tm_mon=6, tm_mday=13, tm_hour=23, tm_min=53, tm_sec=10, tm_wday=1, tm_yday=164, tm_isdst=-1)
>>>
>>> time.ctime(ts)
'Tue Jun 13 23:53:10 2017'
>>> time.asctime(ntu)
'Tue Jun 13 23:53:10 2017'
盗用网上的一张图。理解了以上这些，基本可以满足日常编码需要，以后有需要，再继续补充吧！
转化关系图