Django selecting objects in_bulk()

Question

I am trying to use in_bulk method, although something goes wrong

First I pick values into list that I need to select in bulk:

states = StateObjectRelation.objects.filter(state=int(3), content_type=int(ctype.id))

Then convert them to list:

list = values_list('content_id', flat=True)

Now selecting the items in_bulk:

projects = Project.objects.in_bulk(list)

Give me the following error:

Exception Value:
in_bulk() must be provided with a list of IDs.

If i print out the values that are in list I get the following:

>>> print list
[1L]
>>> print list.values()
[{'state_id': 3L, 'content_id': 1L, 'id': 1L, 'content_type_id': 29L}]

list is a name of built-in list type, it's a very bad idea to name variable like that. — vartec
– vartec, Commented May 6, 2011 at 10:00

Herman Schaaf · Accepted Answer · 2012-12-13 16:05:45Z

9

Firstly, it's a mistake to call your list list, since that's a reserved word (function) in Python. But as for your question, all you need to do is make a list of your query first, like this:

list2 = list(l)

or like this (slower):

list2 = [l for l in list]

Then you really have a real list object, and not just something that appears like one when you print it. Now you should be able to call

projects = Project.objects.in_bulk(list2)

edited Dec 13, 2012 at 16:05

answered May 6, 2011 at 10:00

Herman Schaaf

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2 Comments

Herman Schaaf Over a year ago

I'll see whether I can think of something more efficient, but it's not too horrible, and in your case it should be fine. Also, as @vartec mentioned, please change your variable name to something else.

Geekfish Over a year ago

Why not just wrap it in list() ? as in list(values_list('content_id', flat=True)). Obviously you shouldn't call the queryset "list"...

Geekfish · Accepted Answer · 2012-12-13 15:49:13Z

4

I would simply do it like that, using list():

ids = list(your_queryset.values_list('content_id', flat=True))
projects = Project.objects.in_bulk(ids)

answered Dec 13, 2012 at 15:49

Geekfish

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Comments

Jason Lee Eaton · Accepted Answer · 2016-09-15 19:33:33Z

1

I know this has been answered, but these answers seem to be inefficient. The output of a flat values_list() is perfectly acceptable as the list of values for in_bulk()

content_id_pks = StateObjectRelation.objects.filter(state=int(3), content_type=int(ctype.id)).values_list('content_id', flat=True)
projects = Project.objects.in_bulk(content_id_pks)

Note that projects isn't a queryset, it's a dictionary, which presents it's own set of handling problems in re: efficiency.

answered Sep 15, 2016 at 19:33

Jason Lee Eaton

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