Bryan Olson wrote: > Steven Bethard wrote: > > Well, I couldn't find where the general semantics of a negative stride > > index are defined, but for sequences at least[1]: > > > > "The slice of s from i to j with step k is defined as the sequence of > > items with index x = i + n*k such that 0 <= n < (j-i)/k." > > > > This seems to contradict list behavior though. [...] > > The conclusion is inescapable: Python's handling of negative > subscripts is a wart. Indexing from the high end is too useful > to give up, but it should be specified by the slicing/indexing > operation, not by the value of the index expression.
It is a Python gotcha, but the identity X[-1] == X[len(X)-1] holds and is very usefull IMO. If you want to slice to the bottom, take 0 as bottom value. The docs have to be extended in this respect. Kay -- http://mail.python.org/mailman/listinfo/python-list
