[Tutor] Finding numeric day in a year...

[Ken G.]

On 06/28/2014 02:36 PM, Steven D'Aprano wrote:
> On Sat, Jun 28, 2014 at 01:59:04PM -0400, Ken G. wrote:
>> I know the correct answer should be 001, but I keep getting 179 which is
>> the correct answer for June 28, 2014 (I think).
> Day 179 of 2014 is June 28 according to my diary, which happens to be
> today. (Well, I'm in Australia, so for me it is yesterday, but for you
> it is today.) So when you do this:
>
> print "Day of year: ", datetime.date.today().strftime("%j")
>
> it prints the day of the year for *today*. If you try it again tomorrow,
> it will print 180. If you wait another week, it will print 187.
>
> The existence of a variable "today" is irrelevant and has nothing to do
> with datetime.date.today. Consider this example:
>
> py> import datetime
> py> today = "the first day of the rest of your life"
> py> datetime.date.today  # just inspect the method
> <built-in method today of type object at 0x607ac0>
> py> datetime.date.today()  # actually call the method
> datetime.date(2014, 6, 29)
> py> today
> 'the first day of the rest of your life'
>
>
>
>> I tried using datecode
>> in various places instead of today but I am still getting 179.
> datecode holds a string, not a date object. To call date methods, you
> need a date object.
>
> py> the_day = datetime.date(2014, 1, 1)
> py> the_day.strftime("%j")
> '001'
>
>
> If you have a date as a string, you can turn it into a date object like
> this:
>
> py> the_day = datetime.datetime.strptime('20140101', '%Y%m%d')
> py> the_day.strftime("%j")
> '001'
>
>
Thank you. Much appreciated.

Ken