List of objects with a unique attribute

Question

I have a list of objects that each have a specific attribute. That attribute is not unique, and I would like to end up with a list of the objects that is a subset of the en

Answer 1

You can use a list comprehension and set:

objects = (object1,object2,object3,object4)
seen = set()
unique = [obj for obj in objects if obj.thing not in seen and not seen.add(obj.thing)]

The above code is equivalent to:

seen = set()
unique = []
for obj in objects:
    if obj.thing not in seen:
        unique.append(obj)
        seen.add(obj.thing)