Python/Numpy fast way to selecting every nth chunk in list
A simple list comprehension can do the job:
[ L[i] for i in range(len(L)) if i%3 != 2 ]
For chunks of size n 
[ L[i] for i in range(len(L)) if i%(n+1) != n ]
Edited for the confusion in the problem, thanks for the answers!
My original problem was that I have a list [1,2,3,4,5,6,7,8], and I want to select every chunk of size x with gap of one. So if I want to select select every other chunk of size 2, the outcome would be [1,2,4,5,7,8]. A chunk size of three would give me [1,2,3,5,6,7].
I've searched a lot on slicing and I couldn't find a way to select chunks instead of element. Make multiple slice operations then join and sort seems a little too expensive. The input can either be a python list or numpy ndarray. Thanks in advance.