pairwise.py

def pairwise(it):
    iterator = iter(it)
    try:
        i = next(iterator)
    except StopIteration:
        return
        yield
    try:
        j = next(iterator)
    except StopIteration:
        return
        yield
    yield(i, j)
    for element in iterator:
        i, j = j, element
        yield(i, j)

i = pairwise([0])
for z in i:
    print(z)

print()

"""
"""

i = pairwise([0, 1])
for z in i:
    print(z)

print()

"""
(0, 1)
"""

i = pairwise([0, 1, 2])
for z in i:
    print(z)

"""
(0, 1)
(1, 2)
"""