Hi to all Numeric Python experts, could not think of a mailing list with better fit to my question which might have an obvious answer: straightforward (naive) Python code to answer my question would be something like import random, itertools n,p,k=100,50,10 # don't try to run with this numbers! ;) print random.sample(list(itertools.combinations(range(n), p)), k) so the goal is to get k (non-repeating) p-subsets of n, where n and p prohibitively large to first populate the full set of combinations. Thank you in advance ;-) -- =------------------------------------------------------------------= Keep in touch www.onerussian.com Yaroslav Halchenko www.ohloh.net/accounts/yarikoptic