Python Forum

Hi,
I found this exercise to improve my knowlegde about list, but I don't understand the delivery of the exercise:

Given a two list. Create a third list by picking an odd-index element from the first list and even index elements from second.

Why in the second list are all even numbers and why instead takes only some elements?

listOne = [3, 6, 9, 12, 15, 18, 21]
listTwo = [4, 8, 12, 16, 20, 24, 28]
listThree = list()

oddElements = listOne[1::2]
print("Element at odd-index positions from list one")
print(oddElements)

EvenElement = listTwo[0::2]
print("Element at odd-index positions from list two")
print(EvenElement)

print("Printing Final third list")
listThree.extend(oddElements)
listThree.extend(EvenElement)
print(listThree)

Output:

Element at odd-index positions from list one
[6, 12, 18]
Element at odd-index positions from list two
[4, 12, 20, 28]
Printing Final third list
[6, 12, 18, 4, 12, 20, 28]

I added my solution, which I don't know if it is correct for the exercise request.
-my code-

listOne = [3, 6, 9, 12, 15, 18, 21]

listTwo = [4, 8, 12, 16, 20, 24, 28]

listThree = []



for i in listOne:
  if i % 2 != 0:
    listThree.insert(0,i)
print(listThree)  

listThree = listThree + listTwo
print(sorted(listThree))

Regards,
RavCoder

The odd and even is the index, not the item. So from listOne it is taking the odd indexes: listOne[1], listOne[3], and listOne[5]. It just so happens that those are all even numbers: 6, 12, and 8. Then it takes the even indexes from listTwo: listTwo[0], listTwo[2], listTwo[4], and listTwo[6].

So I was wrong to execute my code, because I understood to take the elements not the indexes

That's my reading of it.