"Steve Holden" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Antoon Pardon wrote: >> So what happens if you have a module that is collecting string-index >> pair, colleted from various other parts. In one part you >> want to select the last letter, so you pythonically choose -1 as >> index. In an other part you get a result of find and are happy >> with -1 as an indictation for an invalid index. Then these >> data meet. >> > That's when debugging has to start. Mixing data of such types is > somewhat inadvisable, don't you agree? > > I suppose I can't deny that people do things like that, myself included, > but mixing data sets where -1 is variously an error flag and a valid > index is only going to lead to trouble when the combined data is used.
The fact that the -1 return *has* lead to bugs in actual code is the primary reason Guido has currently decided that find and rfind should go. A careful review of current usages in the standard library revealed at least a couple bugs even there. Terry J. Reedy -- http://mail.python.org/mailman/listinfo/python-list