choose_n_without_replacement.py

import random


def unique(values):
    return list(set(values))


def choose_n(values, n):
    assert len(values) <= n
    return random.sample(values, n)


def main():
    words = [u'some', u'word', u'list', u'list']
    print(choose_n(unique(words), 3))


if __name__ == '__main__':
    main()