[Zope-dev] PythonScript for iso_week

[Andy McKay]

Cool. Its all available in Perl as well now.

--
  Andy McKay.


----- Original Message ----- 
From: "Steve Alexander" <steve@cat-box.net>
To: <zope-dev@zope.org>
Sent: Wednesday, March 14, 2001 4:32 AM
Subject: [Zope-dev] PythonScript for iso_week


> Hi folks,
> 
> At various times in the past, people on this list have asked about 
> getting week numbers from DateTime instances.
> 
> I recently had this requirement, so I wrote a PythonScript to produce an 
> iso_week tuple (year, week_number, dow_monday_is_one__sunday_is_seven) 
> from a DateTime instance.
> 
> I've submitted the same to the collector as a feature-enhancement patch 
> to DateTime.py.
> 
> I've tested this by empirically comparing it with the output of 
> mxDateTime's iso_week attribute for all days from 1920-01-01 to some 
> date in the twenty-third century.
> 
> Note also that this iso_week method does not create additional DateTime 
> instances.
> 
> See also http://www.cl.cam.ac.uk/~mgk25/iso-time.html
> 
> --------
> PythonScript iso_week
> 
> Parameters: date
> 
> doy=date.dayOfYear()
> dow=(date.dow()-1)%7
> y=date.year()
> thurs_this_week=doy+(3-dow)
> is_leap=y%4==0 and (y%100!=0 or y%400==0)
> 
> if thurs_this_week>(is_leap and 366 or 365):
>    week=1
>    if dow<8:
>      y=y+1
> else:
>    mon_this_week=doy-dow
>    day_year_begins=(dow-doy+1)%7
>    day_of_4_jan=(day_year_begins+3)%7
>    monday_of_first_week=4-day_of_4_jan
>    week=(mon_this_week-monday_of_first_week)/7+1
> 
>    if week==0:
>      y=y-1
>      is_last_leap=y%4==0 and (y%100!=0 or y%400==0)
>      if day_year_begins==4 or (day_year_begins==5 and is_last_leap):
>        week=53
>      else:
>        week=52
> 
> return y,week,dow+1
> --------
> 
> 
> --
> Steve Alexander
> Software Engineer
> Cat-Box limited
> http://www.cat-box.net
> 
> 
> _______________________________________________
> Zope-Dev maillist  -  Zope-Dev@zope.org
> http://lists.zope.org/mailman/listinfo/zope-dev
> **  No cross posts or HTML encoding!  **
> (Related lists - 
>  http://lists.zope.org/mailman/listinfo/zope-announce
>  http://lists.zope.org/mailman/listinfo/zope )
>