old_contents: from django.contrib import admin
  from django.contrib.admin import SimpleListFilter
  from django.utils.translation import ugettext_lazy as _
  
  from . import models
  
  
  class WithChildrenFilter(SimpleListFilter):
      title = _('Attending with children')
      parameter_name = 'children'
  
      def lookups(self, request, model_admin):
          return (('y', _('with children')),
                  ('n', _('without children')))
  
      def queryset(self, request, queryset):
          if self.value() == 'y':
              queryset = queryset.filter(num_accompanying_children__gt=0)
          elif self.value() == 'n':
              queryset = queryset.filter(num_accompanying_children=0)
          return queryset
  
  
  class ProfileAdmin(admin.ModelAdmin):
      list_display = ('pk', 'user', 'num_accompanying_children',
                      'age_accompanying_children')
      list_display_links = ('pk', 'user')
      list_filter = (WithChildrenFilter,)
  
  
  admin.site.register(models.Profile, ProfileAdmin)
  
new_contents: from django.contrib import admin
  from django.contrib.admin import SimpleListFilter
  from django.utils.translation import ugettext_lazy as _
  
  from . import models
  
  
  class WithChildrenFilter(SimpleListFilter):
      title = _('Attending with children')
      parameter_name = 'children'
  
      def lookups(self, request, model_admin):
          return (('y', _('with children')),
                  ('n', _('without children')))
  
      def queryset(self, request, queryset):
          if self.value() == 'y':
              queryset = queryset.filter(num_accompanying_children__gt=0)
          elif self.value() == 'n':
              queryset = queryset.filter(num_accompanying_children=0)
          return queryset
  
  
  class ProfileAdmin(admin.ModelAdmin):
      list_display = ('pk', 'user', 'display_name', 'full_name', 
                      'num_accompanying_children', 'age_accompanying_children')
      list_display_links = ('pk', 'user')
      list_filter = (WithChildrenFilter,)
  
  
  admin.site.register(models.Profile, ProfileAdmin)
  
subject: Add display_name and full_name to profile admin-listing.