Kolawole Mangabo

Python map() Method Explained.

Do you know that it’s possible to process iterables without a Loop? The map method is really useful when you need to perform the same operation on all items of an iterable (list, sets, etc).

The map() method takes two arguments:

  • a function object
  • an iterable or multiple iterable

The function passed to the map() method will perform some action on each element of the iterable passed as an argument.

Example

>>> fruits = ["lemon", "orange", "banana"]
>>> def add_is_a_fruit(fruit):
...     return fruit + " is a fruit."
...
>>> new_fruits = map(add_is_a_fruit, fruits)
<map object at 0x7f7fe85e6460>
>>> new_fruits = list(new_fruits)
>>> new_fruits
['lemon is a fruit.', 'orange is a fruit.', 'banana is a fruit.']

Notice that you have to convert the returned map object into an iterable so you can work with it easily.

It’s also possible to use map() with lambda functions.

>>> new_fruits = map(lambda fruit: fruit + " is a fruit.", fruits)
>>> new_fruits = list(new_fruits)
>>> new_fruits
['lemon is a fruit.', 'orange is a fruit.', 'banana is a fruit.']

You can learn more about the method here.