5e_map.md

Mapping

Map

The map function takes a function as its first parameter and an iterable as its second. It returns a new iterable where every element in the old iterable has been passed through the function. It is also variadic: it takes multiple iterables, in which case the iterables will be harvested to supply arguments to the function.
map is equivalent to Haskell's map function when it is used with a single iterable, or zipWithN when used with N iterables.
It can be thought of as this generator:

def map(f, *xs):
    for pairing in zip(xs):
        yield f(*pairing)

Starmap

itertools.starmap is like map, but it only accepts one iterable, and the elements from the iterable are each unpacked into its function.

def starmap(f, xs):
    for args in xs:
        yield f(*args)