nwise

from itertools import tee
from collections import deque

def nwise(iterable, n=2):
    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
    temp = deque()

    for elem in iterable:
        temp.append(elem)
        if len(temp) == n:
            yield tuple(temp)
            temp.popleft()


assert list(nwise([])) == []
assert list(nwise(['s0'])) == []

assert list(nwise(['s0', 's1', 's2'])) == [('s0', 's1'), ('s1', 's2')], list(nwise(['s0', 's1', 's2']))

assert list(nwise(['s0', 's1', 's2', 's3'])) == [('s0', 's1'), ('s1', 's2'), ('s2', 's3')], res
assert list(nwise(['s0', 's1', 's2', 's3', 's4', 's5', 's6'], n=4)) == [
    ('s0', 's1', 's2', 's3'), ('s1', 's2', 's3', 's4'), ('s2', 's3', 's4', 's5'), ('s3', 's4', 's5', 's6')
]
assert list(nwise(['s0', 's1', 's2', 's3', 's4'], n=3)) == [
    ('s0', 's1', 's2'), ('s1', 's2', 's3'), ('s2', 's3', 's4')
]

assert list(nwise(['s0', 's1', 's2', 's3', 's4', 's5', 's6'], 5)) == [
    ('s0', 's1', 's2', 's3', 's4'), ('s1', 's2', 's3', 's4', 's5'), ('s2', 's3', 's4', 's5', 's6')
]