if you don't know the algorithm you could easily get it subtly wrong

but the only method involved here is string.strip(), so i don't think this is an example of the problem you describe

    import random
    n = 100
    ws = [line.strip() for line in open('/usr/share/dict/words')]
    for i in range(n):
        j = random.randrange(i, len(ws))
        ws[i], ws[j] = ws[j], ws[i]
        print(ws[i])

(did i fuck that up)

and yeah probably calling random.sample would be better. and usually import random is better than writing your own rng. but not always