Remove getCallback indirection in modules Instead, assume that the imported module contains the Callback class that was previously returned by getCallback. This is done to prevent a circular import (caused by the __init__ importing a submodule).

from django.contrib import admin
from django.contrib.sites.models import Site


class SiteAdmin(admin.ModelAdmin):
    list_display = ('domain', 'name')
    search_fields = ('domain', 'name')

admin.site.register(Site, SiteAdmin)