[Tutor] What is this an example of (and how can i use it?)

[kevin parks]

I am afraid that in the long layoff in python has meant some new  
constructs have passed me by. In googling around I found some nice  
little code I want to use, but i don't quite understand it, how it is  
called, and what it is an example of. I guess there are generators and  
iterators now and it seems this might be an example of one of those  
new constructs. Can anyone explain what it is i am looking at, how it  
is called, and what it is an example of so that I can look it up:

def roundrobin(*iterables):
     "roundrobin('ABC', 'D', 'EF') --> A D E B F C"
     # Recipe credited to George Sakkis
     pending = len(iterables)
     nexts = cycle(iter(it).next for it in iterables)
     while pending:
         try:
             for next in nexts:
                 yield next()
         except StopIteration:
             pending -= 1
             nexts = cycle(islice(nexts, pending))