On Thu, 18 Oct 2007 02:49:12 -0300, Gabriel Genellina wrote: > A reversed object is rather simple: it stores the original sequence (a > reference, as usual, not a copy!) and the next index to use, starting at > len-1. Each time the next() method is called, the index is decremented > until it goes below 0.
... > Note that the starting index is determined at creation time, not when > the iteration begins. So, if you create a reversed object over a list > containing 3 elements, the first returned element will be seq[2], then > seq[1], then seq[0]. It doesn't matter if you modify the list after > creating the reversed object but before starting the iteration: it will > start at seq[2] even if it's not the last item, and will silently stop > if seq[2] is not a valid index anymore. You know, that's probably the *least* intuitive behaviour possible. For reversed() to iterate over the input as it was at creation time is a reasonable design choice; for it to iterate over the input as it is at call time is also a reasonable design choice; but for it to iterate over some unholy mutant melding of the sequence as-it-was and as-it-is is simply bizarre. I hope it just fell out of the implementation and wasn't a deliberate design choice. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
