- Author:
- I159
- Posted:
- September 21, 2011
- Language:
- Python
- Version:
- Not specified
- Score:
- 0 (after 0 ratings)
This manager is based on the economical method of randomization. It usable in related models. For support this behavior required to be defined as default manger.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 | from django.db import models
import random
class RandomQueryset(models.query.QuerySet):
"""Custom queryset"""
def randomize(self):
"""Returns random object from given model
without 'shot the foot' ['?'][0]"""
count = self.count()
random_index = random.randint(0, count - 1)
return self.all()[random_index]
class RandomManager(models.Manager):
"""Custom manager, returns RandomQueryset instance.
Usable for related objects, required to be defined as default manager."""
use_for_related_fields = True
def get_query_set(self):
return RandomQueryset(self.model, using=self._db)
def randomize(self):
return self.get_query_set().randomize()
In use:
In [1]: from myapp.models import PostPages
In [2]: post = PostPages.objects.filter(image_gallery__isnull=False).distinct().randomize()
In [3]: post.image_gallery.randomize()
Out[3]: <Image: /site_media/media/img/vkrasa_gomukhasana.jpg>
|
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