如何用Python找出今年6月16日(wk24)的周数?


当前回答

datetime。Date有一个iscalendar()方法,它返回一个包含日历周的元组:

>>> import datetime
>>> datetime.date(2010, 6, 16).isocalendar()[1]
24

datetime.date. iscalendar()是一个实例方法,返回一个元组,其中包含给定日期实例的年份、周号和星期。

在Python 3.9+中,iscalendar()返回一个包含年份、星期和星期的命名元组,这意味着您可以使用命名属性显式地访问星期:

>>> import datetime
>>> datetime.date(2010, 6, 16).isocalendar().week
24

其他回答

一般要获取当前周数(从周日开始):

from datetime import *
today = datetime.today()
print today.strftime("%U")

我相信date. iscalendar()将是答案。本文解释了ISO 8601日历背后的数学原理。查看Python文档的datetime页面的date. iscalendar()部分。

>>> dt = datetime.date(2010, 6, 16) 
>>> wk = dt.isocalendar()[1]
24

. iscalendar()返回一个三元组,包含(年,星期数,星期天数)。dt. iscalendar()[0]返回年份,dt. iscalendar()[1]返回周数,dt. iscalendar()[2]返回周数。尽可能的简单。

iscalendar()对于某些日期返回错误的年和周数值:

Python 2.7.3 (default, Feb 27 2014, 19:58:35) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import datetime as dt
>>> myDateTime = dt.datetime.strptime("20141229T000000.000Z",'%Y%m%dT%H%M%S.%fZ')
>>> yr,weekNumber,weekDay = myDateTime.isocalendar()
>>> print "Year is " + str(yr) + ", weekNumber is " + str(weekNumber)
Year is 2015, weekNumber is 1

与Mark Ransom的方法相比:

>>> yr = myDateTime.year
>>> weekNumber = ((myDateTime - dt.datetime(yr,1,1)).days/7) + 1
>>> print "Year is " + str(yr) + ", weekNumber is " + str(weekNumber)
Year is 2014, weekNumber is 52

有许多周编号系统。下面是最常见的系统代码示例:

ISO: First week starts with Monday and must contain the January 4th (or first Thursday of the year). The ISO calendar is already implemented in Python: >>> from datetime import date >>> date(2014, 12, 29).isocalendar()[:2] (2015, 1) North American: First week starts with Sunday and must contain the January 1st. The following code is my modified version of Python's ISO calendar implementation for the North American system: from datetime import date def week_from_date(date_object): date_ordinal = date_object.toordinal() year = date_object.year week = ((date_ordinal - _week1_start_ordinal(year)) // 7) + 1 if week >= 52: if date_ordinal >= _week1_start_ordinal(year + 1): year += 1 week = 1 return year, week def _week1_start_ordinal(year): jan1 = date(year, 1, 1) jan1_ordinal = jan1.toordinal() jan1_weekday = jan1.weekday() week1_start_ordinal = jan1_ordinal - ((jan1_weekday + 1) % 7) return week1_start_ordinal >>> from datetime import date >>> week_from_date(date(2014, 12, 29)) (2015, 1) MMWR (CDC): First week starts with Sunday and must contain the January 4th (or first Wednesday of the year). I created the epiweeks package specifically for this numbering system (also has support for the ISO system). Here is an example: >>> from datetime import date >>> from epiweeks import Week >>> Week.fromdate(date(2014, 12, 29)) (2014, 53)

datetime。Date有一个iscalendar()方法,它返回一个包含日历周的元组:

>>> import datetime
>>> datetime.date(2010, 6, 16).isocalendar()[1]
24

datetime.date. iscalendar()是一个实例方法,返回一个元组,其中包含给定日期实例的年份、周号和星期。

在Python 3.9+中,iscalendar()返回一个包含年份、星期和星期的命名元组,这意味着您可以使用命名属性显式地访问星期:

>>> import datetime
>>> datetime.date(2010, 6, 16).isocalendar().week
24