[Django][DRF] How to get UNORDERED queryset from `.filter`?

first of all, I'm not a native at ENG so plz be patient my ENG skills or give me some advice.

(FYI, Django ver 3.2.9 & DRF ver 3.12.4 with postgres ver 12.7)

I'm writing API creating a post by using drf serializer. And I've been facing a problem with "the order of tags adding to the post".

• post and tag models are connected through M2M field

which means, let's say I add tags a, b, and c on a post. The logic I use as follows.

# class Serializer
# def create(instance):
# instance : specific post instance

tags = ['t', 'a', 'g', 's']
Tag.objects.bulk_create([Tag(name = tag) for tag in tags])
instance.tags.add(*[tag for tag in Tag.objects.filter(name__in = tags)])

run this at first. tags are added in this order

TagQuerySet[Tag<'t'>, Tag<'a'>, Tag<'g'>, Tag<'s'>]

And my API takes the other create request that include the tags of the existing like,

tags = ['g', 'a', 's']

django add in the sorted order, not in the order I want like,

# tags new created instance
TagQuerySet[Tag<'a'>, Tag<'g'>, Tag<'s'>]

I know the method that adding tags following my list order using for loop

for tag in tags:
    instance.tags.add(Tag.objects.get(name=tag))

but it's not efficient.

So my question is

• how to get queryset using .filter following my list order.
• If there is no way for this. What is the efficient way for adding tags to post

You can add another column to Tag class namely priority and whenever you insert rows add the priority of the value.

You can then order by priority something like this:

tags = [('t', 4), ('a', 2), ('g', 1), ('s', 3)]
Tag.objects.bulk_create([Tag(name = tag[0], priority=tag[1]) for tag in tags])

Tag.objects.all().order_by('priority')

also the the optimized version of this:

for tag in tags:
    instance.tags.add(Tag.objects.get(name=tag))

is this:

tags_db = Tag.objects.filter(name__in=[tag for tag in tags])
instance.tags.set(list(tags_db))

Edit:

Sorting using python:

my_order_list = ['g', 'a', 's', 't']
sorted(Tag.objects.all(), key=lambda x: my_order_list.index(x.name))

Sorting using sql case expressions:

Tag.objects.raw("
   SELECT * FROM Tag ORDER BY 
       CASE name
         WHEN 'g' THEN 1
         WHEN 'a' THEN 2
         WHEN 's' THEN 3
         ELSE 4 
       END
")