Repeat each item in a list a number of times specified in another list

Question

I have two lists, x and y:

>>> x = [2, 3, 4]
>>> y = [1, 2, 3]

I want to use these to create a

Answer 1

Simple using for loop.

>>> x = [2, 3, 4]
>>> y = [1, 2, 3]
>>> final = []
>>> for index, item in enumerate(y):
        final.extend([x[index]]*item)