Iterate over all pairs of consecutive items in a list [duplicate]

Answer 1

Look at pairwise at itertools recipes: http://docs.python.org/2/library/itertools.html#recipes

Quoting from there:

def pairwise(iterable):
    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
    a, b = tee(iterable)
    next(b, None)
    return izip(a, b)

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A General Version

A general version, that yields tuples of any given positive natural size, may look like that:

def nwise(iterable, n=2):                                                      
    iters = tee(iterable, n)                                                     
    for i, it in enumerate(iters):                                               
        next(islice(it, i, i), None)                                               
    return izip(*iters)