|
##########################
# Python Time Conversion #
##########################
------------------------
-- 一. 時間的表示類型 --
------------------------
py中可能涉及的time有四種類型
1. time string
2. datetime
tuple(datetime obj)
3. time tuple(time
obj)
4. timestamp
1. time string
string是最簡單的表示time的方式
如如下代碼生成的即為string
----------------------------------------------
>>> time.ctime()
'Mon Dec 17 21:02:55
2012'
----------------------------------------------
或者更簡單的生成一個字符串
----------------------------------------------
time_string =
'2000-01-02 03:04:05'
----------------------------------------------
2. datetime tuple(datetime obj)
datetime tuple是datetime.datetime對象類型
----------------------------------------------
>>>
datetime.now()
datetime.datetime(2012,
12, 17, 21, 3, 44, 139715)
----------------------------------------------
3. time tuple(time obj)
time tuple是time.struct_time對象類型
----------------------------------------------
time.struct_time(tm_year=2008, tm_mon=11, tm_mday=10, tm_hour=17,
tm_min=53, tm_sec=59, tm_wday=0, tm_yday=315, tm_isdst=-1)
----------------------------------------------
4. timestamp
時間戳類型:自1970年1月1日(00:00:00 GMT)以來的秒數
----------------------------------------------
>>> time.time()
1355749338.05917
----------------------------------------------
------------------------
-- 二. 類型之間的轉換 --
------------------------
1. string 轉換為其它
初始化:
date_str = "2008-11-10
17:53:59"
1.1 string --> datetime obj
導入:
import datetime
datetime.datetime.strptime(string, format)
eg
----------------------------------------------
>>> dt_obj =
datetime.datetime.strptime(date_str, "%Y-%m-%d %H:%M:%S")
>>> dt_obj
datetime.datetime(2008,
11, 10, 17, 53, 59)
----------------------------------------------
1.2 string --> time obj
導入:
import time
time.strptime(string,
format)
eg
----------------------------------------------
#time模塊有類似datetime中的strptime()函數
>>> date_str =
"2008-11-10 17:53:59"
>>> t_obj =
time.strptime(date_str, "%Y-%m-%d %H:%M:%S")
>>> t_obj
time.struct_time(tm_year=2008, tm_mon=11, tm_mday=10, tm_hour=17,
tm_min=53, tm_sec=59, tm_wday=0, tm_yday=315, tm_isdst=-1)
----------------------------------------------
2. datetime obj轉換為其它
datetime obj轉換為其它類型,用的都是datetime的函數
初始化:
dt_obj =
datetime.datetime(2008, 11, 10, 17, 53, 59)
2.1 dt obj --> string
----------------------------------------------
date_str =
dt_obj.strftime("%Y-%m-%d %H:%M:%S")
----------------------------------------------
2.2 dt obj --> time obj
----------------------------------------------
time_tuple =
dt_obj.timetuple()
----------------------------------------------
3. time obj轉換為其它
初始化:
time_tuple = (2008, 11,
12, 13, 51, 18, 2, 317, 0)
3.1 time obj --> string
----------------------------------------------
date_str =
time.strftime("%Y-%m-%d %H:%M:%S", time_tuple)
----------------------------------------------
3.2 time obj --> datetime obj
----------------------------------------------
datetime.datetime(*time_tuple[0:6])
----------------------------------------------
3.3 time obj --> timestamp
----------------------------------------------
ts =
time.mktime(time_tuple)
----------------------------------------------
4. timestamp轉換為其它
初始化:
timestamp =
1226527167.595983
--!!--注意以下兩種都使用local時區(qū)
4.1 timestamp --> dt obj
----------------------------------------------
dt_obj =
datetime.fromtimestamp(timestamp)
----------------------------------------------
4.2 timestamp --> time obj
----------------------------------------------
time_tuple =
time.localtime(timestamp)
----------------------------------------------
--!!--以下兩種方式和時區(qū)相關,比較標準時區(qū)時間和本地時區(qū)時間
4.3 使用UTC --> dt obj
----------------------------------------------
#本地時區(qū)時間
>>>
datetime.datetime.fromtimestamp(tm)
datetime.datetime(2012,
12, 17, 23, 39, 58, 401881)
#標準時區(qū)時間
>>>
datetime.datetime.utcfromtimestamp(tm)
datetime.datetime(2012,
12, 17, 15, 39, 58, 401881)
----------------------------------------------
4.4 使用UTC --> time obj
----------------------------------------------
#本地時區(qū)時間
>>>
time.localtime(tm)
time.struct_time(tm_year=2012, tm_mon=12, tm_mday=17, tm_hour=23,
tm_min=39, tm_sec=58, tm_wday=0, tm_yday=352, tm_isdst=0)
#標準時區(qū)時間
>>>
time.gmtime(tm)
time.struct_time(tm_year=2012, tm_mon=12, tm_mday=17, tm_hour=15,
tm_min=39, tm_sec=58, tm_wday=0, tm_yday=352, tm_isdst=0)
----------------------------------------------
|
