Python常用模块-时间模块(time & datetime)
作者:尹正杰
版权声明:原创作品,谢绝转载!否则将追究法律责任。
一.初始time模块
#!/usr/bin/env python
#_*_coding:utf-8_*_
#@author :yinzhengjie
#blog:http://www.cnblogs.com/yinzhengjie/tag/python%E8%87%AA%E5%8A%A8%E5%8C%96%E8%BF%90%E7%BB%B4%E4%B9%8B%E8%B7%AF/
#EMAIL:y1053419035@qq.com import time """"
模块的分类:
模块本质就是一个“*.py”文件,大致分为以下三类:
1>.内置模块,指的是存在Python解释器内部的模块,如time模块;
2>>第三方模块,指的是安装好Python后的lib文件夹中的模块;
3>.自定义模块,指的是你自己写的Python程序;
""" print(time.time()) #返回当前的时间戳,表示从1971年1月1日"00:00:00"到此刻时间节点的秒数。 s = time.localtime() #创建一个时间对象,也可以说是在结构化时间对象,返回本地时间的struct_time对象格式。
print(s)
print(s.tm_year) #获取年份。
print(s.tm_mon) #获取月份。 s2 = time.gmtime() #返回utc时间的struc时间对象格式。
print(s2) #以上代码执行结果如下:
1520176127.9244497
time.struct_time(tm_year=2018, tm_mon=3, tm_mday=4, tm_hour=23, tm_min=8, tm_sec=47, tm_wday=6, tm_yday=63, tm_isdst=0)
2018
3
time.struct_time(tm_year=2018, tm_mon=3, tm_mday=4, tm_hour=15, tm_min=8, tm_sec=47, tm_wday=6, tm_yday=63, tm_isdst=0)
二.时间模块的相互转换
1.转换助记图
2.案例展示
#!/usr/bin/env python
#_*_coding:utf-8_*_
#@author :yinzhengjie
#blog:http://www.cnblogs.com/yinzhengjie/tag/python%E8%87%AA%E5%8A%A8%E5%8C%96%E8%BF%90%E7%BB%B4%E4%B9%8B%E8%B7%AF/
#EMAIL:y1053419035@qq.com import time s = time.localtime(31245244545) #结构化时间对象,可以将时间戳转换成结构化时间。
print(s) s2 = time.mktime(time.localtime()) #将结构化时间转换成时间戳。
print(s2) s3 = time.strftime("%Y-%m-%d",time.localtime()) #将结构化时间转换成字符串时间。
print(s3) s4 = time.strptime("1993:05:19","%Y:%m:%d") #将字符串时间转换成结构化时间。
print(s4) #以上代码执行结果如下:
time.struct_time(tm_year=2960, tm_mon=2, tm_mday=15, tm_hour=2, tm_min=35, tm_sec=45, tm_wday=4, tm_yday=46, tm_isdst=0)
1520176194.0
2018-03-04
time.struct_time(tm_year=1993, tm_mon=5, tm_mday=19, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=2, tm_yday=139, tm_isdst=-1)
三.time扩充
#!/usr/bin/env python
#_*_coding:utf-8_*_
#@author :yinzhengjie
#blog:http://www.cnblogs.com/yinzhengjie/tag/python%E8%87%AA%E5%8A%A8%E5%8C%96%E8%BF%90%E7%BB%B4%E4%B9%8B%E8%B7%AF/
#EMAIL:y1053419035@qq.com import time
print(time.asctime(time.localtime())) #将结构化时间转换成字符串时间。
print(time.ctime(565656446)) #将时间戳转换成字符串时间。 time.sleep(2) #让程序暂停2秒钟,用于模拟I/O阻塞,并不占用CPU资源。 #以上代码执行结果如下:
Sun Mar 4 23:11:16 2018
Sat Dec 5 06:47:26 1987
四.time模块小试牛刀
#!/usr/bin/env python
#_*_coding:utf-8_*_
#@author :yinzhengjie
#blog:http://www.cnblogs.com/yinzhengjie/tag/python%E8%87%AA%E5%8A%A8%E5%8C%96%E8%BF%90%E7%BB%B4%E4%B9%8B%E8%B7%AF/
#EMAIL:y1053419035@qq.com import time s = "2018-03-04" def ChangeTime(string,number,format="%Y-%m-%d"):
StructTime = time.strptime(string,format )
print(StructTime)
StampTime = time.mktime(StructTime)
print(StampTime)
NewStamp = StampTime + 3600 * 24 * number
NewStringTime = time.strftime(format, time.localtime(NewStamp))
print(NewStringTime) ChangeTime(s,3) #推算3日后的时间 #以上代码执行结果如下:
time.struct_time(tm_year=2018, tm_mon=3, tm_mday=4, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=6, tm_yday=63, tm_isdst=-1)
1520092800.0
2018-03-07
五.datetime介绍
#!/usr/bin/env python
#_*_coding:utf-8_*_
#@author :yinzhengjie
#blog:http://www.cnblogs.com/yinzhengjie/tag/python%E8%87%AA%E5%8A%A8%E5%8C%96%E8%BF%90%E7%BB%B4%E4%B9%8B%E8%B7%AF/
#EMAIL:y1053419035@qq.com
import time,datetime print(datetime.datetime.now()) #打印当前系统时间 print(datetime.date.fromtimestamp(time.time())) #时间戳直接转成日期格式如:2018-03-04 print(datetime.datetime.now() + datetime.timedelta(3)) #当前时间+3天 print(datetime.datetime.now() + datetime.timedelta(-3)) #当前时间-3天 print(datetime.datetime.now() + datetime.timedelta(hours=3)) #当前时间+3小时 print(datetime.datetime.now() + datetime.timedelta(minutes=30)) #当前时间+30分 c_time = datetime.datetime.now()
print(c_time.replace(minute=3,hour=2)) ##时间替换 #以上代码执行结果如下:
2018-03-04 23:12:13.477416
2018-03-04
2018-03-07 23:12:13.477416
2018-03-01 23:12:13.477416
2018-03-05 02:12:13.477416
2018-03-04 23:42:13.477416
2018-03-04 02:03:13.477416
六.关于格式化参数的详细说明
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. |