Python in Functional Style: How to add 2 lists of integers without using loops

Usually you’d add a list of integers this way:

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You can do it functionally without any loops in different ways:



Using map and a lambda that adds them up

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or you can import the add operator as a named function

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Ever zipped two lists into a list of tuples?

There’s another more convoluted way if you want to play with “zip”.

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When you zip the lists a and b, you end up with a list of tuples of matching elements from the given lists.

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you could now map a function to add the elements within each tuple on that list.


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Notice how we don’t convert to list after zip, we can work directly with the zip iterator, we only convert to list with the final map iterator.

Python 2 & 3 Note:

In Python 2 it’s not necessary to use list(), the map() and zip() methods return lists there. But stay away from Python 2, a lot of projects are now discontinuing support.