Itertools

Compare Neighboring Values Lazily with itertools.pairwise

Many data-processing tasks are really questions about transitions: Did a measurement increase? How long was the gap between two events? Did a state change? Is a sequence sorted? These problems need neighboring values, not arbitrary pairs. Python 3.10 added itertools.pairwise() for exactly this pattern. It produces overlapping adjacent pairs lazily, which makes the intent clearer than manual indexing and lets the same code work with lists, generators, files, and other iterables.