Function map()

Applies function to every item of an iterable and returns a list of the results.

map(function, iterable [, …])

function

Required. A function that is used to create a new list.

iterable

Required. An iterable object or multiple comma-separated iterable objects.

If additional iterable arguments are passed, function must take that many arguments and is applied to the items from all iterables in parallel.

If one iterable is shorter than another it is assumed to be extended with None items.

If function is None, the identity function is assumed

With multiple iterables, the iterator stops when the shortest iterable is exhausted.

For cases where the function inputs are already arranged into argument tuples, see itertools.starmap().

>>> map(lambda x: x+x, (1, 2, 3))
[2, 4, 6]
>>> map(lambda x, y: x/y, (1, 4, 9), (1, 2, 3))
[1, 2, 3]
>>> map(lambda x, y, z: x+y+z, (1, 2, 3), (1, 4, 9), (1, 16, 27))
[3, 22, 39]

>>> map(None, [True, False])
[True, False]
>>> map(None, ['a', 'b'], [1, 2])
[('a', 1), ('b', 2)]
>>> map(None, ['a', 'b'], [1, 2, 3])
[('a', 1), ('b', 2), (None, 3)]