itertools.chain.from_iterable() vs itertools.product()
itertools.chain.from_iterable() and itertools.product() are both Python Itertools Module APIs, and choosing between them is a common point of confusion. This page compares their syntax, parameters, return values, and typical use cases so you can pick the right one. itertools.chain.from_iterable(): Alternative chain that takes a single iterable of iterables. Its syntax is itertools.chain.from_iterable(iterable), and it returns iterator itertools.product(): Cartesian product of input iterables (like nested for-loops). Its syntax is itertools.product(*iterables, repeat=1), and it returns iterator of tuples Example of itertools.chain.from_iterable(): list(chain.from_iterable([[1,2],[3,4]])) # [1,2,3,4]. Example of itertools.product(): list(product([1,2], ["a","b"]))
# [(1,"a"), (1,"b"), (2,"a"), (2,"b")]. Read the full references for itertools.chain.from_iterable() and itertools.product() to see parameters, edge cases, and example code side by side. Other Itertools Module APIs worth comparing: itertools.chain(), itertools.permutations(), itertools.combinations(), itertools.combinations_with_replacement(), itertools.cycle(), itertools.repeat(). Both belong to the Itertools Module category in the Python Reference documentation. Try both in the Python playground to see the behavioral difference live.