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我在尝试计算“ DoesNotExist 错误”时遇到了问题，我试图找到正确的方法来管理无应答结果，但是我继续遇到“ DoesNotExist”或“ Object hast not Attribute DoestNotExists”的问题

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')
173531 次浏览
小开

This line

 except Vehicle.vehicledevice.device.DoesNotExist

means look for device instance for DoesNotExist exception, but there's none, because it's on class level, you want something like

 except Device.DoesNotExist
小开
最佳答案

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

小开

The solution that i believe is best and optimized is:

try:
#your code
except "ModelName".DoesNotExist:
#your code
小开

First way:

try:
# Your code goes here
except Model.DoesNotExist:
# Handle error here

Another way to handle not found in Django. It raises Http404 instead of the model’s DoesNotExist exception.

https://docs.djangoproject.com/en/3.1/topics/http/shortcuts/#get-object-or-404

from django.shortcuts import get_object_or_404


def get_data(request):
obj = get_object_or_404(Model, pk=1)

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