Question

Let’s say I have 2 following lists:

list1 = [1,1,1,1]
list2 = [3,3,3,3]

I want the result of join to be:

list3 [4,4,4,4]

What’s would be the best way to do it?

Answer 1

Extremely similar to Ignacio’s answer, but for a tiny bit more brevity:

list3 = [sum(i) for i in zip(list1, list2)]

or

list3 = map(sum, zip(list1, list2))

I prefer the map version myself.

Edit: As JBernardo rightly points out, if using Python 2.x you should replace zip with its iterator counterpart in itertools.izip for efficiency, but zip uses iterators by default in Python 3.