Django DoesNotExist

I am having issues on trying to figure "DoesNotExist Errors", I have tried to find the right way for manage the no answer results, however I continue having issues on "DoesNotExist" or "Object hast not Attribute DoestNotExists"

    from django.http import HttpResponse
    from django.contrib.sites.models import Site
    from django.utils import simplejson

    from vehicles.models import *
    from gpstracking.models import *


    def request_statuses(request):

        data = []
        vehicles = Vehicle.objects.filter()
        Vehicle.vehicledevice_
        for vehicle in vehicles:
            try:
                vehicledevice = vehicle.vehicledevice_set.get(is_joined__exact = True)
                imei = vehicledevice.device.imei
                try:
                    lastposition = vehicledevice.device.devicetrack_set.latest('date_time_process')
                    altitude = lastposition.altitude
                    latitude = lastposition.latitude
                    longitude =  lastposition.longitude
                    date_time_process = lastposition.date_time_process.strftime("%Y-%m-%d %H:%M:%S"),
                    date_time_created = lastposition.created.strftime("%Y-%m-%d %H:%M:%S")
                except Vehicle.vehicledevice.device.DoesNotExist:
                    lastposition = None
                    altitude = None
                    latitude = None
                    longitude = None
                    date_time_process = None
                    date_time_created = None
            except Vehicle.DoesNotExist:
                vehicledevice = None
                imei = ''

            item = [
                    vehicle.vehicle_type.name,
                    imei,
                    altitude,
                    "Lat %s Lng %s" % (latitude, longitude),
                    date_time_process,
                    date_time_created,
                    '', 
                    ''
                    ]
            data.append(item)
        statuses = {
                    "sEcho": 1,
                    "iTotalRecords": vehicles.count(),
                    "iTotalDisplayRecords": vehicles.count(),
                    "aaData": data
                    } 
        json = simplejson.dumps(statuses)
        return HttpResponse(json, mimetype='application/json')

I have found the solution to this issue using ObjectDoesNotExist on this way

    from django.core.exceptions import ObjectDoesNotExist
    ......

    try:
      # try something
    except ObjectDoesNotExist:
      # do something

After this, my code works as I need

Thanks any way, your post help me to solve my issue

From: stackoverflow.com/q/16181188