Hi, Suppose you have N items, say N = 10. Now a subset of these items are selected given by a list A of indices. Lets say that items A = [2,5,7] are selected. Assume now that you delete some of the items given by the indices S = [1,4,8]. This means that the list of indices A must be updated, since items have been deleted. For this particular case the updated selection list A becomes A = [1,3,5]. Is there some smart numpy way of doing this index update of the selected items in A without looping? Typically N is large. Best regards, Mads -- +-----------------------------------------------------+ | Mads Ipsen | +----------------------+------------------------------+ | Gåsebæksvej 7, 4. tv | | | DK-2500 Valby | phone: +45-29716388 | | Denmark | email: mads.ipsen@gmail.com | +----------------------+------------------------------+