On Apr 23, 2007, at 7:38 AM, Antoon Pardon wrote: > The following is part of the explanation on slices in the > tutorial: > > The best way to remember how slices work is to think of the indices as > pointing between characters, with the left edge of the first character > numbered 0. Then the right edge of the last character of a string of n > characters has index n, for example: > > +---+---+---+---+---+ > | H | e | l | p | A | > +---+---+---+---+---+ > 0 1 2 3 4 5 > -5 -4 -3 -2 -1 > > This is all very well with a simple slice like: > > "HelpA"[2:4] => "lp" > > > But it give the wrong idea when using the following extended slice: > > "HelpA"[4:2:-1] => "Ap" > > So this doesn't result in the reverse of the previous expression while > the explanation above suggest it does. > > > So I suggest to drop this.
But 'drop' means to let or make (something) fall vertically... :-) At that point in the tutorial, step values had not been discussed. Just a bit lower down on the page you'll find a link to 'Sequence Types' where you'll find an explanation of stepping you'll perhaps find more satisfactory. hth, Michael --- "Those who don't understand UNIX are condemned to reinvent it, poorly." --Henry Spencer -- http://mail.python.org/mailman/listinfo/python-list
