将Django DeleteView与酥脆形式一起使用时出现VariableDoesNotExist错误

Question

我无法获得清晰的表格，并且django的DeleteView内置功能无法协同工作。如果我从模板中删除了松脆的逻辑，则删除工作正常。带有松脆形式的添加和更新逻辑以及分别内置于CreateView和UpdateView的django也可以正常工作-只是删除失败。我知道这看起来与其他问题相似，但我不认为这是重复的问题-这些问题不使用DeleteView也不适用他们的答案（再次，我的看法是……不当然）。

错误是：/ EventSubType / 12 / delete /

处的VariableDoesNotExist

在[{'False'：False，'None'：None，'True'：True}，{}，{}，{'eventsubtype'：，'view'：，'对象'：}]

models.py
class EventSubType(models.Model):
    subtype     = models.CharField(max_length=25,)
    event_type  = models.ForeignKey('EventType', on_delete=models.PROTECT)
    description = models.CharField(max_length=1000, null=True, blank=True)

    def __str__(self):
        return str(self.subtype)

    def get_absolute_url(self):
        return reverse('eventsubtype_edit', kwargs={'pk': self.pk})

views.py
class EventSubTypeDelete(LoginRequiredMixin, PermissionRequiredMixin, DeleteView):
    permission_required = "<snip>.delete_eventsubtype"
    model = EventSubType
    form_class = EventSubTypeDeleteForm
    success_url = reverse_lazy('eventsubtype_list')

forms.py
class EventSubTypeDeleteForm(forms.ModelForm):
    class Meta:
        model = EventSubType
        fields = ['subtype',]

    def __init__(self, *args, **kwargs):
        super(EventSubTypeDeleteForm, self).__init__(*args, **kwargs)
        self.helper = FormHelper(self)
        self.helper.layout.append(Submit('save', 'Delete'))

template
{% extends "base.html" %}
{% load crispy_forms_tags %}
{% block content %}
    <h1>Event Sub Type Delete</h1>
    {% crispy form %}
{% endblock %}