Gift Cards view, Sort By raises exception

Login to Site, go to Gift Cards page (/giftcards/), under Sort By drop box, select either Price or Availability, and click Search - raises the following exception:

AttributeError at /giftcards/
'list' object has no attribute 'order_by'
Request Method: GET
Request URL:    http://localhost:8000/giftcards/?search=&min_amount=&max_amount=&sort=price
Django Version: 5.1.3
Exception Type: AttributeError
Exception Value:    
'list' object has no attribute 'order_by'
Exception Location: C:\Working\GitHub\GiftGenius\giftcards\services.py, line 29, in sort_results
Raised during:  giftcards.views.giftcard_list
Python Executable:  C:\Working\GitHub\GiftGenius\.venv\Scripts\python.exe
Python Version: 3.12.7
Python Path:    
['C:\\Working\\GitHub\\GiftGenius',
 'C:\\Program Files\\Python312\\python312.zip',
 'C:\\Program Files\\Python312\\DLLs',
 'C:\\Program Files\\Python312\\Lib',
 'C:\\Program Files\\Python312',
 'C:\\Working\\GitHub\\GiftGenius\\.venv',
 'C:\\Working\\GitHub\\GiftGenius\\.venv\\Lib\\site-packages']
Server time:    Tue, 19 Nov 2024 12:00:25 -0500

Complete Traceback:

Environment:

Request Method: GET
Request URL: http://localhost:8000/giftcards/?search=&min_amount=&max_amount=&sort=price

Django Version: 5.1.3
Python Version: 3.12.7
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'crispy_forms',
 'crispy_tailwind',
 'accounts.apps.AccountsConfig',
 'main',
 'giftcards',
 'shop.apps.ShopConfig']
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 "C:\Working\GitHub\GiftGenius\.venv\Lib\site-packages\django\core\handlers\exception.py", line 55, in inner
    response = get_response(request)
               ^^^^^^^^^^^^^^^^^^^^^
  File "C:\Working\GitHub\GiftGenius\.venv\Lib\site-packages\django\core\handlers\base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Working\GitHub\GiftGenius\.venv\Lib\site-packages\django\contrib\auth\decorators.py", line 60, in _view_wrapper
    return view_func(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Working\GitHub\GiftGenius\giftcards\views.py", line 23, in giftcard_list
    giftcards = search_engine.sort_results(sort_criteria)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Working\GitHub\GiftGenius\giftcards\services.py", line 29, in sort_results
    return self.search_results.order_by("amount")
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Exception Type: AttributeError at /giftcards/
Exception Value: 'list' object has no attribute 'order_by'

DevidasGhorpade / GiftGenius_v1.0

Gift Cards view, Sort By raises exception #4

Complete Traceback: