Sliding window over data from the sequence

slide.py

import itertools

def slide(seq, n=2):
    """Returns a sliding window (of width n) over data from the sequence
    
    s -> (s0, s1, ..., s[n-1]), (s1, s2, ..., sn), ...
    """
    it = iter(seq)
    result = tuple(itertools.islice(it, n))
    if len(result) == n:
        yield result
    for elem in it:
        result = result[1:] + (elem,)
        yield result