On 5 October 2012 14:47, Richard D. Moores <rdmoo...@gmail.com> wrote: > I thought it would be useful to have a script that would tell me what > the date n days from today would be. The docs > (<http://docs.python.org/py3k/library/datetime.html#module-datetime>) > seem to get me almost there. I can compute the number of days between > 2 dates, and the number of days between a date and today: > > Python 3.2.3 (default, Apr 11 2012, 07:12:16) [MSC v.1500 64 bit (AMD64)] > > import time > from datetime import date, timedelta >>>> date1 = date(2001, 9, 11) >>>> date1 > datetime.date(2001, 9, 11) >>>> date2 = date(2003, 4, 15) >>>> date2 > datetime.date(2003, 4, 15) >>>> date2 - date1 > datetime.timedelta(581) >>>> days_delta = date2 - date1 >>>> days_delta.days > 581 >>>> today = date.today() >>>>> today > datetime.date(2012, 10, 5) >>>> print(today) > 2012-10-05 >>>> time_to_date = today - date1 >>>> time_to_date > datetime.timedelta(4042) >>>> print(time_to_date) > 4042 days, 0:00:00 >>>> print(time_to_date.days) > 4042 > > However, brick wall: > > timedelta.days = 100 > Traceback (most recent call last): > File "<string>", line 1, in <fragment> > builtins.TypeError: can't set attributes of built-in/extension type > 'datetime.timedelta'
timedlta objects are immutable. Once an object is created it's values cannot be changed (much like a tuple). You need to create a new timedelta object: >>> from datetime import datetime, timedelta >>> dt = datetime.now() >>> print dt 2012-10-05 15:14:55.841000 >>> d = dt.date() >>> print d 2012-10-05 >>> td = timedelta(days=7) >>> print dt + td 2012-10-12 15:14:55.841000 >>> print d + td 2012-10-12 Oscar _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
