Which file is used in import statement for 'MultipleObjectsReturne' exception

I am using this code

except MultipleObjectsReturned:
    return HttpResponse('some error')

but i get this error

global name 'MultipleObjectsReturned' is not defined

You can do either:

from django.core.exceptions import MultipleObjectsReturned

except MultipleObjectsReturned as e:
    return HttpResponse(e)

Or:

except yourmodel.MultipleObjectsReturned as e:
    return HttpResponse(e)

https://docs.djangoproject.com/en/1.3/ref/exceptions/#django.core.exceptions.MultipleObjectsReturned

A base version of this exception is provided in django.core.exceptions; each model class contains a subclassed version that can be used to identify the specific object type that has returned multiple objects.

from django.core.exceptions import MultipleObjectsReturned