Untitled

try:
    import numpy as np
    def create_buffer(size):
        arr = np.zeros(size+1, dtype=np.bool)
        return arr, arr.size
except ImportError:
    def create_buffer(size):
        arr = [False, ] * (size+1)
        return arr, len(arr)

# ...

def main(args):
    max_integer = parse_args(args)
    buffer, upper_bound = create_buffer(max_integer)
    atkin(buffer, upper_bound)