Question

I am using Django to develop a course registration site for an educational institution.

Suppose I have two Django query sets, one that comprises of courses that occupy session 1 (set A) and one that comprises of courses in session 2 (set B):

A = session1.courses.all()
B = session2.courses.all()

There is much overlap between these two query sets.

What is an efficient way to obtain the set of courses within set B, but not in set A?

I believe this is equivalent to taking out the intersection of the two sets from set B.

Thank you!

Answer 1

A.exclude(pk__in = B) should work