Do something if there’s only one entry in the QuerySet, something else otherwise

[Tzu-ping Chung]

Hi all,

I’m wondering what is the best way to handle the logic “if there’s only one entry in the QuerySet, do things with that entry”. What I do currently is

qs = MyModel.objects.filter(...)

try:

    obj = qs.get()

except (MyModel.DoesNotExist, MyModel.MultipleObjectsReturned):

    for obj in qs:    # Something like this

        print(obj)

else:

    do_something(obj)

This works pretty well, but slightly annoys me because .get() clones and performs an extra fetch on the QuerySet. I guess I have two questions:

1. Why does .get() need to perform the extra clone even when there are no arguments? This seems unnecessary to me.
2. Is there a better way to do what I want to do?

Thanks in advance.

[Vinicius Assef]

Explicit is better than implicit. So, I would stick with:


qs = MyModel.objects.filter(...)

if len(qs) == 0:
    # no record found
elif len(qs) == 1:
    # one record found
else:
    # many records found

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