Python adding every other item

Question

If I have a list with say [7,6,5,4,3,2,1] how can I make it add upp every second number, for instance 7 + 5 + 3 + 1?

I've tried adding mylist[0] + mylist[2] etc but it is very tedious.

Answer 1

sum(mylist[::2])

the mylist[::2] takes every other item, and sum sums it.

If you want to have the first, third, fifth et cetera item, you can use:

sum(list[1::2])

This will first omit the first item (with the 1 part), then do the same as in the first command.