在Admin中对计算字段进行自定义过滤的FieldError

Question

我正在尝试对admin中的计算字段使用自定义过滤器。我遵循了文档和其他示例，并得到了以下错误：无法将关键字“ kit_frequency”解析为字段。我哪里出错了？

class KitFrequencyFilter(admin.SimpleListFilter):
    title = 'Frequency'
    parameter_name = 'kit_frequency'

    def lookups(self, request, model_admin):
        return (
            ('Monthly', 'Monthly'),
            ('Bi-Monthly', 'Bi-Monthly'),
            ('Quarterly', 'Quarterly'),
        )
    def queryset(self, request, queryset):
        value = self.value()

        if value == 'Monthly':
            return queryset.filter(kit_frequency='Monthly')
        if value == 'Bi-Monthly':
            return queryset.filter(kit_frequency='Bi-Monthly')
        if value == 'Quarterly':
            return queryset.filter(kit_frequency='Quarterly')
        return  queryset


@admin.register(Contact)
class ContactAdmin(ImportExportModelAdmin):
    resource_class = ContactImportResource

    list_display = ('full_name','program_code','kit_frequency','author','first_name1', 'last_name1', 'first_name2','last_name2','address1','city','province','postal_code','active_status')
    list_filter = ['program_code','author', KitFrequencyFilter]

（简体）型号：

class Contact(models.Model):
    first_name1 = models.CharField(max_length=100, verbose_name='First Name')
    last_name1 = models.CharField(max_length=100, verbose_name='Last Name', blank=True)
etc...

    def get_kit_frequency(self):
        from programs.models import Program
        kit_frequency = Program.objects.get(program_code=self.program_code).kit_frequency
        return kit_frequency
kit_frequency = property(get_kit_frequency)