Generate non-repeating, no sequential numbers

Question

how does one use code to do this:

produce 15 random numbers [EDIT: from 1 - 15] that are not in any order, and that only occur once eg.

1 4, 2, 5, 3, 6, 8, 7

Answer 1

Generate the full list, then shuffle it.

Python:

import random
r = range(1, 16)
random.shuffle(r)

A random number generator by itself can, almost by definition, not do what you want. It would need to keep track of all the numbers already generated, which would be as memory-hungry as the solution sketched above.