Login

sort_by_id_sequence

Author:
simon
Posted:
May 15, 2008
Language:
Python
Version:
.96
Score:
0 (after 0 ratings)

I needed to sort a set of objects (a QuerySet for example) by an externally provided list of IDs - for example:

>>> writers = Writer.objects.all()
>>> sort_by_id_sequence(writers, [3, 1, 2])
[<Writer id: 3>, <Writer id: 1>, <Writer id: 2>]

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
def sort_by_id_sequence(objects, id_sequence):
    max_score = len(objects)
    def sort_score_for_object(obj):
        # A lower score is better
        id = obj.id
        try:
            return id_sequence.index(id)
        except ValueError: # Not found
            return max_score
    return sorted(objects, key=sort_score_for_object)

More like this

  1. Serializer factory with Django Rest Framework by julio 3 months, 2 weeks ago
  2. Image compression before saving the new model / work with JPG, PNG by Schleidens 4 months ago
  3. Help text hyperlinks by sa2812 5 months ago
  4. Stuff by NixonDash 7 months, 1 week ago
  5. Add custom fields to the built-in Group model by jmoppel 9 months, 1 week ago

Comments

Please login first before commenting.