Multiply every other element in a list

Question

I have a list, let\'s say: list = [6,2,6,2,6,2,6], and I want it to create a new list with every other element multiplied by 2 and every other element multiplie

Answer 1

You can reconstruct the list with list comprehenstion and enumerate function, like this

>>> [item * 2 if index % 2 == 0 else item for index, item in enumerate(lst)]
[12, 2, 12, 2, 12, 2, 12]

enumerate function gives the current index of them item in the iterable and the current item, in each iteration. We then use the condition

item * 2 if index % 2 == 0 else item

to decide the actual value to be used. Here, if index % 2 == 0 then item * 2 will be used otherwise item will be used as it is.