PYTHON

django check for empty onetoone exists

>>> try:
>>>     restaurant = p2.restaurant
>>> except Restaurant.DoesNotExist:
>>>     print "Place has no restaurant!"
>>> else:
>>>     # Do something with p2's restaurant here.

django filter empty onetoone exists

User.objects.annotate(
    no_reports=~Exists(Reports.objects.filter(user__eq=OuterRef('pk')))
).filter(
    email__startswith='a',
    no_reports=True
)