builtins.ValueError при перенаправлении с 2 kwargs

Question

Я хочу выполнить перенаправление в одном из моих представлений, и я столкнулся с ошибкой с небольшим количеством деталей.

Мой urls.py:

urlpatterns = [ 
    url(
      regex=r'^(?P<pk>[0-9]+)/$', 
      view=views.SheetDetailView.as_view(), 
      name='detail' 
     ), 
    url(
      regex=r'^(?P<pk>[0-9]+)/branch/(?P<branch_slug>[a-zA-Z0-9-]+)/$', 
      view=views.SheetDetailView.as_view(), 
      name='detail' 
     ), 

] 

Мой взгляд

class SheetDetailView(LoginRequiredMixin, UserIsLinkedToSheetMixin, UserPassesTestMixin, DetailView): 
    model = Sheet 
    def get_context_data(self, **kwargs): 
     context = super(SheetDetailView, self).get_context_data(**kwargs) 
     #if no branch is requested, show the master 
     if 'branch_slug' in self.kwargs: 
      branch = self.get_object().get_branch(self.kwargs['branch_slug']) 
      context['branch']=branch 
      return context 
     else: 
      # redirect to master      
      sheet_id = self.get_object().pk 
      branch_slug = self.get_object().get_master().slug      
      return redirect(reverse('sheets:detail', kwargs={'pk':sheet_id, 'branch_slug':branch_slug}), permanent=False) 

И мое сообщение об ошибке:

Traceback (most recent call last): 
    File "/usr/local/lib/python3.5/site-packages/django/contrib/staticfiles/handlers.py", line 63, in __call__ 
    return self.application(environ, start_response) 
    File "/usr/local/lib/python3.5/site-packages/django/core/handlers/wsgi.py", line 177, in __call__ 
    response = self.get_response(request) 
    File "/usr/local/lib/python3.5/site-packages/django/core/handlers/base.py", line 230, in get_response 
    response = self.handle_uncaught_exception(request, resolver, sys.exc_info()) 
    File "/usr/local/lib/python3.5/site-packages/django/core/handlers/base.py", line 289, in handle_uncaught_exception 
    return debug.technical_500_response(request, *exc_info) 
    File "/usr/local/lib/python3.5/site-packages/django_extensions/management/technical_response.py", line 6, in null_technical_500_response 
    six.reraise(exc_type, exc_value, tb) 
    File "/usr/local/lib/python3.5/site-packages/six.py", line 686, in reraise 
    raise value 
    File "/usr/local/lib/python3.5/site-packages/django/core/handlers/base.py", line 174, in get_response 
    response = self.process_exception_by_middleware(e, request) 
    File "/usr/local/lib/python3.5/site-packages/django/core/handlers/base.py", line 172, in get_response 
    response = response.render() 
    File "/usr/local/lib/python3.5/site-packages/django/template/response.py", line 160, in render 
    self.content = self.rendered_content 
    File "/usr/local/lib/python3.5/site-packages/django/template/response.py", line 137, in rendered_content 
    content = template.render(context, self._request) 
    File "/usr/local/lib/python3.5/site-packages/django/template/backends/django.py", line 92, in render 
    context = make_context(context, request) 
    File "/usr/local/lib/python3.5/site-packages/django/template/context.py", line 291, in make_context 
    context.push(original_context) 
    File "/usr/local/lib/python3.5/site-packages/django/template/context.py", line 61, in push 
    return ContextDict(self, *dicts, **kwargs) 
    File "/usr/local/lib/python3.5/site-packages/django/template/context.py", line 20, in __init__ 
    super(ContextDict, self).__init__(*args, **kwargs) 
ValueError: dictionary update sequence element #0 has length 0; 2 is required 

Когда я распечатать reverse() результат и вставить его в свой браузер , все в порядке.

Answer 1

Вы пытаетесь вернуть перенаправление с get_context_data. Но этот метод должен возвращать контекст для рендеринга шаблона, как следует из названия. Вероятно, вам нужно поставить эту конкретную часть логики в get или dispatch.