Python 3.10+itertoolsfunction

itertools.pairwise

itertools

Successive overlapping pairs: (s0,s1), (s1,s2), … (3.10+).

Syntax

itertools.pairwise(iterable)

Unlike the old zip(seq, seq[1:]) trick, pairwise works on any iterable — generators and infinite streams included — because it lazily keeps only the previous element around. With fewer than two input items it yields nothing.

Examples

import itertools
print(list(itertools.pairwise([1, 2, 3, 4])))   # → [(1, 2), (2, 3), (3, 4)]
print(list(itertools.pairwise('abc')))  # → [('a', 'b'), ('b', 'c')]
print([b - a for a, b in itertools.pairwise([10, 13, 12, 20])])  # → [3, -1, 8]
print(all(a <= b for a, b in itertools.pairwise([1, 2, 2, 5])))  # → True
print(list(itertools.pairwise([7])))  # → []

See also

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