Python 学习入门（10）—— 时间

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Python格式化日期时间的函数为datetime.datetime.strftime()；由字符串转为日期型的函数为：datetime.datetime.strptime()，两个函数都涉及日期时间的格式化字符串，列举如下：

%a     Abbreviated weekday name
%A     Full weekday name
%b     Abbreviated month name
%B     Full month name
%c     Date and time representation appropriate for locale
%d    Day of month as decimal number (01 - 31)
%H     Hour in 24-hour format (00 - 23)
%I     Hour in 12-hour format (01 - 12)
%j     Day of year as decimal number (001 - 366)
%m     Month as decimal number (01 - 12)
%M     Minute as decimal number (00 - 59)
%p     Current locale's A.M./P.M. indicator for 12-hour clock
%S     Second as decimal number (00 - 59)
%U     Week of year as decimal number, with Sunday as first day of week (00 - 51)
%w     Weekday as decimal number (0 - 6; Sunday is 0)
%W     Week of year as decimal number, with Monday as first day of week (00 - 51)
%x     Date representation for current locale
%X     Time representation for current locale
%y     Year without century, as decimal number (00 - 99)
%Y    Year with century, as decimal number
%z, %Z     Time-zone name or abbreviation; no characters if time zone is unknown
%%     Percent sign

示例：

[python] view plaincopyprint?

#!/usr/bin/python
# it-homer in 2013
import sys
reload(sys)
sys.setdefaultencoding("utf-8")
import datetime
def format_time():
t = datetime.datetime.now()
print(t) # 2013-11-20 09:36:51.198680
t = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
print(t) # 2013-11-20 09:39:16
t = datetime.datetime.now().strftime('%b-%d-%y %H:%M:%S')
print(t) # Nov-20-13 09:36:51
t = datetime.datetime.now().strftime('%b-%d-%Y %H:%M:%S')
print(t) # Nov-20-2013 09:36:51
# weekday
t = datetime.datetime.now().strftime('%a %A %U %W %w')
print(t) # Wed Wednesday 46 46 3
# month
t = datetime.datetime.now().strftime('%b %B')
print(t) # Nov November
# day
t = datetime.datetime.now().strftime('%d %j')
print(t) # 20 324
# date and time for locale
t = datetime.datetime.now().strftime('%c')
print(t) # Wed Nov 20 10:15:49 2013
# hour
t = datetime.datetime.now().strftime('%H %l')
print(t) # 10 10
# A.M/P.M
t = datetime.datetime.now().strftime('%p')
print(t) # AM
t = datetime.datetime.now().strftime('%x')
print(t) # 11/20/13
t = datetime.datetime.now().strftime('%X')
print(t) # 10:23:36
t = datetime.datetime.now().strftime('%x %X')
print(t) # 11/20/13 10:24:47
t = datetime.datetime.now().strftime('%z')
print(t) #
t = datetime.datetime.now().strftime('%Z')
print(t) #
# 字符串转换成datetime
t = datetime.datetime.strptime('Nov-20-13 09:42', '%b-%d-%y %H:%M')
print(t) # 2013-11-20 09:42:00
t = datetime.datetime(2013, 11, 20, 9, 42)
print(t) # 2013-11-20 09:42:00
# datetime转换成字符串
t = datetime.datetime.now().strftime('%b-%d-%y %H:%M:%S')
print(t) # Nov-20-13 10:26:40
if __name__ == "__main__":
format_time()

运行结果：

2013-11-20 10:29:26.456640
2013-11-20 10:29:26
Nov-20-13 10:29:26
Nov-20-2013 10:29:26
Wed Wednesday 46 46 3
Nov November
20 324
Wed Nov 20 10:29:26 2013
10 10
AM
11/20/13
10:29:26
11/20/13 10:29:26

2013-11-20 09:42:00
2013-11-20 09:42:00
Nov-20-13 10:29:26

timestamp <--> datetime

[python] view plaincopyprint?

def main():
createtime = int(time.time()) # createtime = 1393316647
basefname2 = datetime.datetime.fromtimestamp(createtime).strftime('%Y-%m-%d %H:%M:%S')
print("timestamp -> datetime: %d : %s" % (createtime, basefname2))
nowtime = datetime.datetime.now()
future = nowtime + datetime.timedelta(minutes = 5)
print("datetime add: %s : %s" % (nowtime, future))
ts = time.mktime(future.timetuple())
print("datetime -> timestamp: %s : %d" % (future, ts))

运行结果：
timestamp -> datetime: 1393317675 : 2014-02-25 16:41:15
datetime add: 2014-02-25 16:41:15.900701 : 2014-02-25 16:46:15.900701
datetime -> timestamp: 2014-02-25 16:46:15.900701 : 1393317975

timestamp 转 datetime

"createtime":1389151309

basefname2 = datetime.datetime.fromtimestamp(createtime).strftime('%Y-%m-%d %H:%M:%S')

结果：

"createtime2":"2014-01-08 11:21:49"

参考： stackoverflow，

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