Question

我正在尝试添加一项功能，限制用户在一个minuate中发布多个。然后我遇到了这个错误，不知道为什么这不起作用。能否请你看看我的错是什么？

class PostCreateView(CreateView):

     model = Post
     form_class = PostForm
     template_name = 'main/add_post.html'

     def form_valid(self,form):

        if not hasattr(self.request.session['last_submitted']):
            last_submitted = pickle.dumps(datetime.datetime.now())
            self.request.session['last_submitted'] = last_submitted
            save_it = True
        else:
            last_submitted = pickle.loads(self.request.session['last_submitted'])
            delta = datetime.datetime.now() - last_submitted
            save_it = (delta.seconds > 60) # assume allow re-submit after 60 seconds

        if save_it:
          self.object = form.save(commit=False)
          # any manual settings go here

          #self.object.category =      Category.objects.filter(category__in=categories).all()

          self.object.moderator = self.request.user
          self.object.image = extract(self.object.url) 
          self.object.thumbnail = extractt(self.object.content)
          self.object.save()
          return HttpResponseRedirect(reverse('post', args=[self.object.slug]))
        else:
           # consider redirect as usual, if the user just clicked twice by mistake
           return self.form_invalid(form) # or Http error code



Traceback:
File "env/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  132.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "env/local/lib/python2.7/site-packages/django/views/generic/base.py" in view
  71.             return self.dispatch(request, *args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/views/generic/base.py" in dispatch
  89.         return handler(request, *args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/views/generic/edit.py" in post
  249.         return super(BaseCreateView, self).post(request, *args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/views/generic/edit.py" in post
  215.             return self.form_valid(form)
File "ebagu/main/views.py" in form_valid
  160.         if not hasattr(self.request.session['last_submitted']):
File "env/local/lib/python2.7/site-packages/django/contrib/sessions/backends/base.py" in __getitem__
  48.         return self._session[key]

Exception Type: KeyError at /add_post/
Exception Value: 'last_submitted'

Answer 1

这看起来：

if not hasattr(self.request.session['last_submitted']):

hasattr接受两个参数，并告诉您对象是否具有特定的属性名称：

hasattr(...)
    hasattr(object, name) -> bool

    Return whether the object has an attribute with the given name.
    (This is done by calling getattr(object, name) and catching exceptions.)

您的意思是使用以下内容吗？

if 'last_submitted' not in self.request.session:

Answer 2

我从您发布的信息中可以告诉您，views.py中的第160行正在触发错误：

if not hasattr(self.request.session['last_submitted']):

您的追踪会抱怨KeyError。它基本上告诉你self.request.session中不存在索引'last_submitted'。

此错误的触发基本上是因为您的代码正在尝试从session内不存在的对象中检索值。

/ add_post /的KeyError /

2 个答案: