Varud

One of the great things I discovered today is defaultdict().   This allows one to create dictionaries with a count for each item in a very compact and powerful way.  Look at this:

>>> for item in NoticeQueueBatchByUser.objects.filter(user=3).values(‘label’,'on_site’):

…   d[item['label']] += 1

…

>>> d.items()

[(u'pagedisplay_violation', 4)]

>>>

>>> from collections import defaultdict

>>> d = defaultdict(int)

>>> for item in ExampleModel.objects.values(‘label’,'other_info’):

…   d[item['label']] += 1

…

>>> d.items()

[(u'key_1', 4),(u'another_key',2)]

>>>

This will give you the number of times each label appears in ExampleModel.objects.values(‘label’,'other_info’)

This entry was posted on Thursday, August 27th, 2009 at 6:10 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.