Add feature to preserve order in .filter(field__in=list) query

[Barney Szabolcs]

filter __in query does not guarantee to preserve order, so I usually sort afterwards using python's sort.

However, in django admin I cannot sort queries using python's sort when manipulating the QuerySet
since I have to return a QuerySet.
So, I'd do something like

queryset.filter(my_field__in=my_values).raw(
    f'order by array_position(ARRAY[{ ",".join(["%s"]*len(my_values)) }]::varchar[], my_field)', 
    params=my_values)

but this does not work...
is there a solution here? (I cannot use raw either since I have a queryset input argument to work with)

UPDATE:

now, I've found a cryptic solution:
​https://stackoverflow.com/a/37648265/1031191

from django.db.models import Case, When

preserved = Case(*[When(my_field=val, then=pos) for pos, val in enumerate(my_values)])
queryset.filter(my_field__in=my_values).order_by(preserved)

I think Django should provide a better way than this.

Maybe queryset.filter(my_field__in_preserve=my_values)