On 03/21/2013 10:20 PM, Steven D'Aprano wrote:
On 22/03/13 12:39, Mitya Sirenef wrote:
>
>> You can do it with groupby like so:
>>
>>
>> from itertools import groupby
>> from operator import itemgetter
>>
>> maxDate = "2013-03-21"
>> mmax = list()
>>
>> obs.sort(key=itemgetter('date'))
>>
>> for k, group in groupby(obs, key=itemgetter('date')):
>> group = [dob for dob in group if dob['realtime_start'] <= maxDate]
>> if group:
>> group.sort(key=itemgetter('realtime_start'))
>> mmax.append(group[-1])
>>
>> pprint.pprint(mmax)
>
>
> This suffers from the same problem of finding six records instead of one,
> and that four of the six have start dates before the given date instead
> of after it.
OP said his code produces the needed result and I think his description
probably doesn't match what he really intends to do (he also said he
wants the same code rewritten using groupby). I reproduced the logic of
his code... hopefully he can step in and clarify!
> Here's another solution that finds all the records that start on or after
> the given data (the poorly named "maxDate") and displays them sorted by
> date.
>
>
> selected = [rec for rec in obs if rec['realtime_start'] >= maxDate]
> selected.sort(key=lambda rec: rec['date'])
> print selected
>
>
>
>
--
Lark's Tongue Guide to Python: http://lightbird.net/larks/
A little bad taste is like a nice dash of paprika.
Dorothy Parker
_______________________________________________
Tutor maillist - Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
