Bill Williams enlightened us with: > I don't know enough about Python internals, but the suggested > solutions all seem to involve scanning bigList. Can this presumably > linear operation be avoided by using dict or similar to find all > occurrences of smallist items in biglist and then deleting those > occurrences?
And how would that beat O(n)? Every element of bigList has to be scanned at one point, either to compare it to every earlier element in bigList and eliminate it, or to compare it to every element in smallList. Run benchmarks on the suggestions, and see which is fastest for yourself. Sybren -- Sybren Stüvel Stüvel IT - http://www.stuvel.eu/ -- http://mail.python.org/mailman/listinfo/python-list