如何确定项目是否是集合中的最后一个项目

Question

I have an arbitrary number of items in a set.

I want to do something different when I am on the last item of the set - is it possible to do so without having to find the length of the set and have a counter variable?

    for e in elements:
        if e is elements[-1]:
            json+='"%s"' % e 
            break
        json+='"%s",' % e 

The above code will work for lists, but cannot work here as splices are not supported for sets.

Answer 1

Leaving my comment above, you could do something like this:

s = {"A", "B", "C"}

i = iter(s)

element = next(i, None)

while element is not None:
    next_element = next(i, None)
    if next_element is None:
        # This is the last element
        print(element * 10)
    else:
        print(element)
    element = next_element

OUTPUT

B
A
CCCCCCCCCC

This is just an example how the final element could be applied a different transformation.