a = set(a) n = sum(item in a for item in b)
Why set? Does it matter if I say that items in A are already unique?
Sets are hash-based, so it's (most probably) far more efficient for sets than for sequences (especially if we say about big/long ones). Regards, *j -- Jan Kaliszewski (zuo) <z...@chopin.edu.pl> -- http://mail.python.org/mailman/listinfo/python-list
