Why doesn't request.user.is_superuser work in Django?

Question

Django

I'm still learning Django. When I make a condition (for example: if self.request.user.is_superuser: ) then I immediately get an Error 500 error.
I work in the admin panel!
from django.contrib.auth.models import User - enabled
PS - please do not scold me, still a beginner)

Answer 1

In BookAdmin:

list_display = ('fio_klient', 'adres')
def get_list_display(self, request):
    if request.user.is_superuser:
        return self.list_display + ('status',)