Why does 'NoneType' object has no attribute 'user' error?

Question

Django

For some reason, the object becomes NoneType even though there is a check before that:

urls = Info.objects.filter(url=url)
if urls is not None:
   if urls.first().user != request.user:

Answer 1

if urls is not None- always True because it .filter(url=url)returns a Queryset - it's always not None.
Use Info.objects.filter(url=url).first()- to get an object or None
If you need to check if there is something in the queryset use .exists()

Answer 2

try like this

urls = Info.objects.filter(url=url).first()
if urls is not None:
   if urls.user != request.user: