Django Admin カスタムフィルタを作成

SimpleListFilter を使って簡単に書ける

from django.contrib import admin

class TicketStatusListFilter(admin.SimpleListFilter):
    title = 'ステータス'
    parameter_name = 'status_set'

    def lookups(self, request, model_admin):
        return (
            ('incomplete', '完了以外'),
            ('completed', '完了'),
        )

    def queryset(self, request, queryset):
        if self.value() == 'incomplete':
            return queryset.exclude(status='completed')
        if self.value() == 'completed':
            return queryset.filter(status='completed')

class TicketAdmin(admin.ModelAdmin):
    list_filter = (TicketStatusListFilter,)