> can anybody point out a situation where you really need > itertools.filterfalse() ? Sometimes you get the predicate as a parameter to another function. This way if you want to filter out things you can easily do it. Other language (such as Clojure) have a "complement" function that removes the need of filterfalse.
For example (Python 3): def percent_spam(is_spam, documents): n_spam = sum(1 for _ in filter(is_spam, documents)) n_ham = sum(1 for _ in filterfalse(is_spam, documents)) return float(n_spam) / (n_ham + n_spam) -- http://mail.python.org/mailman/listinfo/python-list