匹配查询不存在

Question

我试图捕捉异常，但不work.This在我看来代码：

@login_required 
def activities_edit(request, edit): 

    ActivityFormSet = modelformset_factory(Activity, can_delete=True) 
    act_edit= Activity.objects.filter(campaing=1).get(pk=edit) 
    try: 
     if act_edit: 
      if request.method == 'POST': 
       formset = ActivityFormSet(request.POST, request.FILES, queryset=Activity.objects.filter(pk=edit))  
       if formset.is_valid(): 
        formset.save() 
        return HttpResponseRedirect('/activities/') 
      else: 
       formset = ActivityFormSet(queryset=Activity.objects.filter(pk=edit)) 
    except act_edit.DoesNotExist: 
     return HttpResponseRedirect('/activities/') 

我还与试图：“除了act_edit.DoesNotExist：” 但错误仍然存​​在“活动匹配查询不存在”。 有什么想法？

谢谢！

Answer 1

您需要移动可能导致try:子句正文中的异常的语句。

的语法是 “尝试：东西抓东西：” 你东西是try:

act_edit= Activity.objects.filter(campaing=1).get(pk=edit) 
try: 

上面应该是

try: 
    act_edit = Activity.objects.filter(campaing=1).get(pk=edit) 

Answer 2

你有冗余的一点点捕捉异常意味着您不必检查act_edit是否为空，因为如果它为空，它将引发DoesNotExist。此外，该模型有DoesNotExist不是实例。

@login_required 
def activities_edit(request, edit): 

    ActivityFormSet = modelformset_factory(Activity, can_delete=True)  
    try: 
     act_edit= Activity.objects.filter(campaing=1).get(pk=edit) 

     if request.method == 'POST': 
      formset = ActivityFormSet(request.POST, request.FILES, queryset=Activity.objects.filter(pk=edit))  
      if formset.is_valid(): 
       formset.save() 
       return HttpResponseRedirect('/activities/') 
     else: 
      formset = ActivityFormSet(queryset=Activity.objects.filter(pk=edit)) 
      #HttpResponse not returned error here. 
    except Activity.DoesNotExist: 
     return HttpResponseRedirect('/activities/')