**New course!**Every coder should learn

**Generative AI!**

+ 1

# Python array for loop

Came across this for loop in a python challenge. I'm still trying to understand exactly what it's doing. Any help? arr = [(5,8,0), (2,4)] sum = [] for x, *y in arr: sum = sum + y print(sum) https://code.sololearn.com/cP570hyz249g/?ref=app

2 Answers

0

A for loop runs over the primary elements of a container.
So if you wrote:
for x in arr:
x would be first a tuple of three, then a tuple of two, since that are the primary elements.
x, *y now 'unpacks' that primary element, so that you can use the parts in every iteration as x and y.
x will be the first element, and * in this context means: 'Stuff all the rest into a list named y!'
So in first iteration you can use 5 and [8, 0] with x and y, in second iteration 2 and [4].
And since you can add up lists, you get a new list with everything but the first elements.

+ 1

Know it's late but thank you!!!