*_set attributes on Django Models

Question

I have a very basic question about django.db.models.

In this official django tutorial, if you search for word \"choice_set\", you will see tha

Answer 1

This is some ForeignKey magic :)

The Choice model has the attribute poll, which is a ForeignKey to a Poll object. Django adds the convenience method choice_set to Poll objects, which will give a QuerySet containing all Choice objects that reference that Poll Object.

So, given this (pseudo) code

myPoll = Poll(question='Is Django awesome?')
option_yes = Choice(poll=myPoll, choice='Yes')
option_no = Choice(poll=myPoll, choice='No')

You could later run

poll = Poll.objects.get(question='Is Django awesome?')
options = poll.choice_set.all()

and options would include the relevant Choice objects.

You can change the name of this attribute using the related_name option when defining the ForeignKey.