获取formfield_for_dbfield中的主键

Question

在formfield_for_dbfield中获取主键？

我需要在模板“add”（admin）中获取主键。

class ArticleAdmin(admin.ModelAdmin):
    def formfield_for_dbfield(self, db_field, **kwargs):
        if db_field.name == 'text':
            kwargs['widget'] = UploadWidget(attrs={'pk': ???? Article.PK ????})
        return super(ArticleAdmin, self).formfield_for_dbfield(db_field, **kwargs)