Django - catch exception

You have three options here.

1. Provide a 404 handler or 500 handler
2. Catch the exception elsewhere in your code and do appropriate redirection
3. Provide custom middleware with the process_exception implemented

Middleware Example:

class MyExceptionMiddleware(object):
    def process_exception(self, request, exception):
        if not isinstance(exception, SomeExceptionType):
            return None
        return HttpResponse('some message')

You can raise a 404 error or simply redirect user onto your custom error page with error message

from django.http import Http404
#...
def your_view(request)
    #...
    try:
        #... do something
    except:
        raise Http404
        #or
        return redirect('your-custom-error-view-name', error='error messsage')

1. Django 404 error
2. Django redirect

Another suggestion could be to use Django messaging framework to display flash messages, instead of an error page.

from django.contrib import messages
#...
def another_view(request):
    #...
    context = {'foo': 'bar'}
    try:
        #... some stuff here
    except SomeException as e:
        messages.add_message(request, messages.ERROR, e)

    return render(request, 'appname/another_view.html', context)

And then in the view as in Django documentation:

{% if messages %}
<ul class="messages">
    {% for message in messages %}
    <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>{{ message }}</li>
    {% endfor %}
</ul>
{% endif %}