[FIXED] Django 5: custom AdminSite got " 'generator' object is not subscriptable "

Issue

I'm trying to do default admin site just like this

here is settings.INSTALLED_APPS

INSTALLED_APPS = [
    #'django.contrib.admin',
    'core.apps.AppAdminConfig',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'routefilterfeeder.apps.RoutefilterfeederConfig',
]

here is my core.apps

from django.contrib.admin.apps import AdminConfig

class AppAdminConfig(AdminConfig):
    default_site = 'core.admin.AppAdminSite'

and here is my core.admin

from django.contrib.admin import AdminSite
#from django.utils.translation import ugettext_lazy as _
from django.contrib import admin
from django.apps import apps
from django.contrib.admin.sites import site
from operator import itemgetter

# ref: https://unfoldadmin.com/blog/custom-django-admin-site/ 

class AppAdminSite(AdminSite):

    def index(self, request, extra_context=None):
        # Update extra_context with new variables
        return super().index(request, extra_context)
    
    def get_app_list(self, request, app_label=None):
        """
        Return a sorted list of all the installed apps that have been
        registered in this site.
        """
        app_dict = self._build_app_dict(request, app_label)

        # First, sort the models of each app, based on 'admin_priority'
        # Ref: https://forum.djangoproject.com/t/reordering-list-of-models-in-django-admin/5300

        for app_name in app_dict.keys():
            app = app_dict[app_name]
            model_priority = {
                model['object_name']: getattr(
                    site._registry[apps.get_model(app_name, model['object_name'])],
                    'admin_site_priority',
                    9999
                )
                for model in app['models']
            }
            app['models'].sort(key=lambda x: model_priority[x['object_name']])
            yield app


        # Sort the apps alphabetically.
        all_app = sorted(app_dict.values(), key=lambda x: x["name"].lower())

        app_list = []
        prio_list = []

        # Sort the models alphabetically within each app.
        for app in all_app:
            this_config = apps.get_app_config(app["app_label"])

            try :
                this_prio = this_config.admin_site_priority
                prio_list.append([this_prio,app['app_label']])

            except Exception as e:
                app_list.append(app)

        prio_list = sorted(prio_list, key=itemgetter(0))

        for p in prio_list:
            this_app = [a for a in all_app if a['app_label']== p[1]][0]
            app_list.append(this_app)



        return app_list


class MyModelAdmin(admin.ModelAdmin):
    admin_site_priority = 9999

Currently have only one app, with config like

from django.apps import AppConfig


class RoutefilterfeederConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'routefilterfeeder'
    admin_site_priority = 1

I can login to this django site. When I click one model (i.e: Feeders) Under 'routefilterfeeder' the main area show Feeder list display .... no problem.

the nav part display navigation menu 'Home › Routefilterfeeder › Feeders'

But when I click 'Routefilterfeeder' from that nav menu, I got error 'generator' object is not subscriptable', with traceback:

Environment:


Request Method: GET
Request URL: http://127.0.0.1:8000/admin/routefilterfeeder/

Django Version: 5.0
Python Version: 3.10.12
Installed Applications:
['core.apps.AppAdminConfig',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'routefilterfeeder.apps.RoutefilterfeederConfig']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']



Traceback (most recent call last):
  File "/home/bino/Documents/pjxadmin/venv/lib/python3.10/site-packages/django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
  File "/home/bino/Documents/pjxadmin/venv/lib/python3.10/site-packages/django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/bino/Documents/pjxadmin/venv/lib/python3.10/site-packages/django/contrib/admin/sites.py", line 259, in wrapper
    return self.admin_view(view, cacheable)(*args, **kwargs)
  File "/home/bino/Documents/pjxadmin/venv/lib/python3.10/site-packages/django/utils/decorators.py", line 188, in _view_wrapper
    result = _process_exception(request, e)
  File "/home/bino/Documents/pjxadmin/venv/lib/python3.10/site-packages/django/utils/decorators.py", line 186, in _view_wrapper
    response = view_func(request, *args, **kwargs)
  File "/home/bino/Documents/pjxadmin/venv/lib/python3.10/site-packages/django/views/decorators/cache.py", line 80, in _view_wrapper
    response = view_func(request, *args, **kwargs)
  File "/home/bino/Documents/pjxadmin/venv/lib/python3.10/site-packages/django/contrib/admin/sites.py", line 240, in inner
    return view(request, *args, **kwargs)
  File "/home/bino/Documents/pjxadmin/venv/lib/python3.10/site-packages/django/contrib/admin/sites.py", line 577, in app_index
    "title": _("%(app)s administration") % {"app": app_list[0]["name"]},

Exception Type: TypeError at /admin/routefilterfeeder/
Exception Value: 'generator' object is not subscriptable

Kindly please tell me how to fix this.

Solution

The problem is you are returning a generator with the keyword yield in your get_app_list:

app['models'].sort(key=lambda x: model_priority[x['object_name']])
yield app

You state in your docstring:

Return a sorted list of all the installed apps that have been registered in this site.

but by yielding you return a generator object. This object can be iterated over but otherwise does not behave like a list.

To prevent your error you need to return the full list of apps here and not just yielding one app.

Answered By - Martin Achenrainer