Try/except database query in django

I am checking a user's submitted email address against two lists from the database -- a list of authorized domains and a list of authorized email addresses. Currently, if neither are found, it is rainsing a DoesNotExist exception. How would I handle this if neither are found?

Here is the code I currently have in views.py --

def register(request):
    if request.method == 'POST':
        form = UserForm(request.POST)
        if form.is_valid():
            cd = form.cleaned_data
            try:
                email_list = EmailList.objects.get(domain=(cd['email'].split('@')[1]))
            except:
                email_list = EmailList.objects.get(email=cd['email'])
            #  I also need another except if neither works for the validator.
            network= Network.objects.get(network=email_list.network)
            User.objects.create(name=cd['name'], email=cd['email'], network=network)
            return HttpResponseRedirect ('/user/view/')
    el开发者_如何学Cse:
        form = UserForm()
    return render_to_response('register.html',{'form':form}, context_instance = RequestContext(request))

Nested try/except blocks. And don't use a bare except; catch only the exceptions you can handle.

You can nest try/except:

        try:
            email_list = EmailList.objects.get(domain=(cd['email'].split('@')[1]))
        except:
            try:
                email_list = EmailList.objects.get(email=cd['email'])
            except:
                ...do something else

If you are just using these try/except to do a simple test, it's worthwhile to wrap the try/except:

def get_or_none(model, **kwargs):
    try:
        return model.objects.get(**kwargs)
    except model.DoesNotExist:
        return None

Which gives you slightly more readable code:

if get_or_none(EmailList, domain='domain.com'):
    ...do something
elif get_or_none(EmailList, domain='domain.com'):
    ...do something
else:
    ...do something

As Ignacio mentioned in his answer you should always be explicit and catch only the exceptions you intend.