How can I test several sets for items that are unique in Python?

I'm looking for a way to find the unique items between several sets. For example, take these 3 sets.

x = {1, 2}
y = {1, 3}
z = {1, 3, 4, 5}

How can I find the unique items? I'm looking for something like this.

findunique(x, y, z) # {2, 4, 5}

I tried using symmetric_difference with reduce, but that ended up returning {1, 2, 4, 5}.

The only other thing I can think of is to have a dict keep track of how many counts there are for each item, and return only the ones with 1 count. However, that seems very inefficient and unpythonic. What's the "right" way to go about this?

Solution

Combine the sets into one list with chain. Count the number of occurrences of each item with Counter. Select the items that occur only once and make a set of them.

from collections import Counter
from itertools import chain

sets = x,y,z
{x for x, cnt in Counter(chain.from_iterable(sets)).items() if cnt==1}
#{2, 4, 5}

EDITED based on the comments by @jedwards.