Iterate over pairs in a list (circular fashion) in Python

Question

The problem is easy, I want to iterate over each element of the list and the next one in pairs (wrapping the last one with the first).

I\'ve thought about two unpyth

Answer 1

def pairs(lst):
    i = iter(lst)
    first = prev = item = i.next()
    for item in i:
        yield prev, item
        prev = item
    yield item, first

Works on any non-empty sequence, no indexing required.