Pivot returns List instead of ValuesQueryset

[Gogicool-geek]

Hello! I the revision 1.9.0 Pivot returned ValuesQueryset, but in the revision 1.10.0 it returns List:

#rev 1.9.0
..
values_list = queryset.values(*values).annotate(**annotations)
..

#rev 1.10.0
..
values_list = [_swap_dictionary_keys(result, column_alias_map)
                   for result in queryset.values(*values).annotate(**annotations)]
..

Is it posible to return Queryset again?

[martsberger]

This was deliberate in order to support column names that django no longer allows in the queryset.

What is your use case for needing a ValuesQueryset instead of a list?

[Gogicool-geek]

I am using delievered ValuesQueryset in view with django_filter.

# filters.py
class UserGroupListFilter(django_filters.FilterSet):
    """Filter User by user name and group name"""

    name = django_filters.ModelChoiceFilter(
        queryset=User.objects.filter(is_active=True), widget=get_user_autocomplete_widget()
    )
    groups = django_filters.ModelMultipleChoiceFilter(queryset=Group.objects.all())

# views.py
class UsersGroupsPivotView(UserHasSubordinatesMixin, TMSBaseTableView):
    """User & goups pivot table"""

    table_class = UsersGroupsTable
    filterset_class = UserGroupListFilter
    template_name = "layout_list.html"

    def get_queryset(self):
       pivot_table = pivot( subordinates.filter(is_active=True).order_by("name"),
          ["id", "name"],
          "groups__name",
          "pk",
          aggregation=Count,
      )
      return pivot_table

When I upgrade django-pivot up to 1.10 the app comes with error:

Traceback (most recent call last):
  File "/home/gogicool/dev/tms/venv/lib/python3.10/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/home/gogicool/dev/tms/venv/lib/python3.10/site-packages/django/core/handlers/base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/usr/lib/python3.10/contextlib.py", line 79, in inner
    return func(*args, **kwds)
  File "/home/gogicool/dev/tms/venv/lib/python3.10/site-packages/django/views/generic/base.py", line 70, in view
    return self.dispatch(request, *args, **kwargs)
  File "/home/gogicool/dev/tms/venv/lib/python3.10/site-packages/django/contrib/auth/mixins.py", line 71, in dispatch
    return super().dispatch(request, *args, **kwargs)
  File "/home/gogicool/dev/tms/venv/lib/python3.10/site-packages/django/contrib/auth/mixins.py", line 128, in dispatch
    return super().dispatch(request, *args, **kwargs)
  File "/home/gogicool/dev/tms/tms/common/views.py", line 99, in dispatch
    responce = super().dispatch(*args, **kwargs)
  File "/home/gogicool/dev/tms/venv/lib/python3.10/site-packages/django/views/generic/base.py", line 98, in dispatch
    return handler(request, *args, **kwargs)
  File "/home/gogicool/dev/tms/venv/lib/python3.10/site-packages/django_filters/views.py", line 74, in get
    self.filterset = self.get_filterset(filterset_class)
  File "/home/gogicool/dev/tms/venv/lib/python3.10/site-packages/django_filters/views.py", line 38, in get_filterset
    return filterset_class(**kwargs)
  File "/home/gogicool/dev/tms/venv/lib/python3.10/site-packages/django_filters/filterset.py", line 176, in __init__
    model = queryset.model
AttributeError: 'list' object has no attribute 'model'

[geoffrey-eisenbarth]

Just ran into this myself. In my case, I was using pivot() to unstack a date column and then using those values in a QuerySet.annotate() call that calculated compound annual growth rates based on the new columns. This is no longer possible since pivot() is returning a list. Simple example:

My data looks similar to this:

region indicator date value
10180  EMP       2001 [...]
10180  RGP       2001 [...] 
10180  EMP       2010 [...]
10180  RGP       2010 [...]
10180  EMP       2020 [...]
10180  RGP       2020 [...]
[...]
19010  EMP       2001 [...]
19010  RGP       2001 [...]
19010  EMP       2010 [...]
19010  RGP       2010 [...]
19010  EMP       2020 [...]
19010  RGP       2020 [...]

etc for, say 20 regions, two indicators and three dates.

I then run this QuerySet into

pivot(
  qs,
  rows=['region', 'indicator'],
  column='date',
  data='value'
).annotate(
  short_term_cagr=(F('2010') / F('2001')) ** (1 / Value(10.0)) - 1,
  long_term_cagr=(F('2020') / F('2001')) ** (1 / Value(20.0)) - 1,
  region_name=Subquery([...]),
  indicator_name=Subquery([...]),
).values(
  'region_name', 'indicator_name', 'short_term_cagr', 'long_term_cagr',
)

I think it's very useful to be able to annotate a pivoted table. If it seems like it's still possible to support ValuesQuerySet I would be willing to try to put together a PR if I could get some guidance.