arrange keys order in a django queryset

Question

I have this Django query where I get some information from different databases, which I want to expose to the front end:

specifics = PageData.objects.filter(page_id__in=page_ids).values('page_id'). \
                annotate(views=Count('page_id')).                            \
                values('views', 'page__title', 'page__content_size')

that gives me in turn a list of dictionaries - the prompt is for list(specifics):

[
{'page__content_size': 19438L,
  'page__title': u'Bosch Tassimo Charmy anmeldelse. Positivt: Bryggehastighed. Negativt: Placering af vandtanken.  | 96 Grader',
  'views': 5},
 […]
 {'page__content_size': 19395L,
  'page__title': u'Banwood First Go Balance Bike - studiominishop.com',
  'views': 1}
]

I would like to be able to arrange the order of the keys in each dictionary, that means in a required and specific order I am provided. The order would always be the same for each element in the list.

Is there any way to do it in Django or in Python?

What is not clear about the fact that dicts don't guarantee order? — Daniel Roseman, Jun 16 '17 at 09:38
It is clear, I was just wondering if the *does not guarantee* condition may be circumvented or not. — Mattia Paterna, Jun 16 '17 at 09:46

score 2 · Accepted Answer · edited Jun 20 '20 at 09:12

2

You probabily need this:

import collections

OrderedDict dict subclass that remembers the order entries were added

Documentation here: https://docs.python.org/3/library/collections.html#collections.OrderedDict

Here you can find a full example:

https://pymotw.com/2/collections/ordereddict.html

d = collections.OrderedDict()
d['a'] = 'A'
d['b'] = 'B'
d['c'] = 'C'
d['d'] = 'D'
d['e'] = 'E'

for k, v in d.items():
    print k, v`

Hope this help, Ciao!

edited Jun 20 '20 at 09:12

Community

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1

answered Jun 16 '17 at 12:02

Mattia

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13
25

it does exactly what I want, grazie! – Mattia Paterna Jun 27 '17 at 09:40

score 1 · Answer 2 · answered Jun 16 '17 at 09:41

1

This is actually related to python. Here is the cross-reference to the same question which already answered.

Sorting dictionary keys in python

You can only get a sorted representation of the key list.

answered Jun 16 '17 at 09:41

Indika Rajapaksha

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1
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maybe I've been unclear in the explanation, I'd like to arrange the order of the keys, not sort them. And I need the dictionary, not a sorted representation. I'll update my question. – Mattia Paterna Jun 16 '17 at 10:06
@MattiaPaterna You cannot sort the dictionary. Python internally change the order of keys when storing values. – Indika Rajapaksha Jun 16 '17 at 10:08

score 1 · Answer 3 · answered Jun 16 '17 at 11:01

One way is to use values_list instead of values. However this returns list of tuples instead of list of dictionaries but the order is always the same in all elements.

specifics = PageData.objects.filter(
    page_id__in=page_ids).values('page_id').annotate(
    views=Count('page_id')).values_list(
    'views', 'page__title', 'page__content_size')

Values will always be in the order specified in values_list but a tuple instead of dictionaries.

[
    (5, u'Bosch Tassimo Charmy anmeldelse. Positivt: Bryggehastighed. Negativt: Placering af vandtanken.  | 96 Grader', 19438L),
     […]
    (1, u'Banwood First Go Balance Bike - studiominishop.com', 19395L)
]

Python dictionary does not guarantee the order

arrange keys order in a django queryset

3 Answers3