Day5模块-time和datetime模块

模块是封装一段代码来实现某种功能。

分为三类：

1.自定义模块

2.标准库，内置模块

3.开源模块

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1.time模块

 1 >>> import time
 2 #返回处理器时间,3.3后变成了time.process_time()测量处理器运算时间,不包括sleep时间,不稳定
 3 >>> print(time.clock())
 4 2.9933526190766363e-06
 5 >>> print(time.process_time())
 6 0.09360059999999999
 7 
 8 #返回与utc时间的时间差,以秒计算
 9 >>> print(time.altzone)
10 -32400
11 #本地时间
12 >>> print(time.localtime())
13 time.struct_time(tm_year=2017, tm_mon=5, tm_mday=21, tm_hour=20, tm_min=54, tm_s
14 ec=47, tm_wday=6, tm_yday=141, tm_isdst=0)
15 #返回utc时间的struc时间对象格式
16 >>> print(time.gmtime(time.time()-800000))
17 time.struct_time(tm_year=2017, tm_mon=5, tm_mday=12, tm_hour=6, tm_min=41, tm_se
18 c=56, tm_wday=4, tm_yday=132, tm_isdst=0)
19 #返回时间格式
20 >>> print(time.asctime())
21 Sun May 21 20:56:26 2017
22 >>> print(time.asctime(time.localtime()))
23 Sun May 21 20:55:55 2017

View Code

日期字符串转换为时间戳

 1 #将字符串转换成struct对象
 2 >>> string_2_struct = time.strptime("2016/05/22","%Y/%m/%d")
 3 >>> print(string_2_struct)
 4 time.struct_time(tm_year=2016, tm_mon=5, tm_mday=22, tm_hour=0, tm_min=0, tm_sec
 5 =0, tm_wday=6, tm_yday=143, tm_isdst=-1)
 6 >>>
 7 #将struct对象转换为时间戳对象
 8 >>> string_2_stamp = time.mktime(string_2_struct)
 9 >>> print(string_2_stamp)
10 1463846400.0

View Code

时间戳转换为字符串

 1 >>> print(time.time()) #当前utc时间，时间是秒
 2 1495372102.3229373
 3 >>> print(time.gmtime()) #struct对象的时间格式
 4 time.struct_time(tm_year=2017, tm_mon=5, tm_mday=21, tm_hour=13, tm_min=8, tm_se
 5 c=29, tm_wday=6, tm_yday=141, tm_isdst=0)
 6 
 7 #将utc时间戳转换成struct_time格式
 8 >>> print(time.gmtime(time.time()-86640)) 
 9 time.struct_time(tm_year=2017, tm_mon=5, tm_mday=20, tm_hour=13, tm_min=1, tm_se
10 c=42, tm_wday=5, tm_yday=140, tm_isdst=0)
11 #将utc struct_time格式转成指定的字符串格式
12 >>> print(time.strftime("%Y-%m-%d %H:%M:%S",time.gmtime()))
13 2017-05-21 13:07:45

时间加减

 1 >>> import datetime
 2 >>> print("datetime".center(50,'*'))
 3 *********************datetime*********************
 4 >>> print(datetime.datetime.now()) #返回当前时间
 5 2017-05-21 21:12:10.507988
 6 # 时间戳直接转成日期格式 2016-08-19
 7 >>> print(datetime.date.fromtimestamp(time.time())) 
 8 2017-05-21
 9 
10 #返回当前时间
11 >>> print(datetime.datetime.now())
12 2017-05-21 21:17:05.163842
13 #时间戳直接转成日期格式 2016-08-19
14 >>> print(datetime.date.fromtimestamp(time.time()))
15 2017-05-21
16 #当前时间加3天
17 >>> print(datetime.datetime.now()+datetime.timedelta(3))
18 2017-05-24 21:17:39.092782
19 #当前时间减3天
20 >>> print(datetime.datetime.now()+datetime.timedelta(-3))
21 2017-05-18 21:17:46.039180
22 #当前时间加3小时
23 >>> print(datetime.datetime.now()+datetime.timedelta(hours=3))
24 2017-05-22 00:18:01.337055
25 #当前时间加30分钟
26 >>> print(datetime.datetime.now()+datetime.timedelta(minutes=30))
27 2017-05-21 21:49:16.833373

View Code

时间替换

1 >>> c_time = datetime.datetime.now()
2 >>> print(c_time.replace(minute=3,hour=2))
3 2017-05-21 02:03:05.940477
4 >>> print(datetime.datetime.now)
5 <built-in method now of type object at 0x0000000067D262C0>
6 >>> print(datetime.datetime.now())
7 2017-05-21 21:23:49.137948

View Code

Directive	Meaning	Notes
`%a`	Locale’s abbreviated weekday name.
`%A`	Locale’s full weekday name.
`%b`	Locale’s abbreviated month name.
`%B`	Locale’s full month name.
`%c`	Locale’s appropriate date and time representation.
`%d`	Day of the month as a decimal number [01,31].
`%H`	Hour (24-hour clock) as a decimal number [00,23].
`%I`	Hour (12-hour clock) as a decimal number [01,12].
`%j`	Day of the year as a decimal number [001,366].
`%m`	Month as a decimal number [01,12].
`%M`	Minute as a decimal number [00,59].
`%p`	Locale’s equivalent of either AM or PM.	(1)
`%S`	Second as a decimal number [00,61].	(2)
`%U`	Week number of the year (Sunday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Sunday are considered to be in week 0.	(3)
`%w`	Weekday as a decimal number [0(Sunday),6].
`%W`	Week number of the year (Monday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Monday are considered to be in week 0.	(3)
`%x`	Locale’s appropriate date representation.
`%X`	Locale’s appropriate time representation.
`%y`	Year without century as a decimal number [00,99].
`%Y`	Year with century as a decimal number.
`%z`	Time zone offset indicating a positive or negative time difference from UTC/GMT of the form +HHMM or -HHMM, where H represents decimal hour digits and M represents decimal minute digits [-23:59, +23:59].
`%Z`	Time zone name (no characters if no time zone exists).
`%%`	A literal `'%'` character.

字符串、时间格式、utc时间的转换关系

a.字符串转换为utc时间

>>> time.strptime("2016/05/22","%Y/%m/%d")
time.struct_time(tm_year=2016, tm_mon=5, tm_mday=22, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=6, tm_yday=143, tm_isdst=-1)

>>> struct_time = time.strptime("2016/05/22","%Y/%m/%d")
>>> time.mktime(struct_time)
1463846400.0

b.utc时间转换为字符串

>>> time.gmtime(1463846400.0)
time.struct_time(tm_year=2016, tm_mon=5, tm_mday=21, tm_hour=16, tm_min=0, tm_se
c=0, tm_wday=5, tm_yday=142, tm_isdst=0)

>>> time.strftime("%Y-%m-%d %H:%M:%S",time.gmtime())
'2017-05-21 13:30:47'