Question

Given set s, which of the segments below looks better?

if len(s) == 1:
    v = s.copy().pop()
    # important stuff using variable v takes place here

or

if len(s) == 1:
    v = s.pop()
    s.add(v)
    # important stuff using variable v takes place here

or

if len(s) == 1:
    for v in s:
        # important stuff using variable v takes place here

I guess the last segment is the most efficient, but doesn’t it look silly to use a loop that never actually loops?

Why don’t python sets have an alternative method to pop that doesn’t remove the item?

This may seem like a trivial question, but as I’ve run into this scenario multiple times it has become an itch in need of scratching!

Answer 1

You can assign the only element to v like this:

(v,) = the_set

It raises a exception if the_set doesn’t contain exactly one item.