Unordered list generation in python

Question

I'd like to create a million unordered list, xrange(1, 1000000) for eg gives me an ordered list. I think I need something like xrange but generates it in an unordered fashion. I think I can generate a list manually by looping around random.randint and some manual checks to guarantee uniqueness of number in list but I reckon it would be time consuming. Any ideas?

Answer 1

import random
L = range(1, 1000000)
random.shuffle(L)  # shuffles in-place

on Python3, you will need to use

L = list(range(1, 1000000))
random.shuffle(L)  # shuffles in-place

Answer 2

Use the random module from NumPy. Specifically np.random.permutation

>>> import numpy as np
>>> np.random.permutation(5)
array([2, 1, 0, 3, 4])

Answer 3

If you're using numpy you can use permutation:

numpy.random.permutation(10)
>> array([1, 7, 6, 0, 5, 9, 2, 3, 8, 4])