On Mon, Jul 13, 2015 at 9:23 PM, Steven D'Aprano <st...@pearwood.info> wrote: > On Tue, 14 Jul 2015 01:12 pm, Ian Kelly wrote: > >> On Mon, Jul 13, 2015 at 10:56 AM, Roel Schroeven <r...@roelschroeven.net> >> wrote: >>> Hi, >>> >>> Quick question: why does str have both index() and find(), while list >>> only has index()? Is there a reason for that, or is it just an historical >>> accident? >> >> Historical accident, I think. If it were to be redone, I doubt that >> str.find would exist. The problem with it is that it returns -1 to >> indicate that the argument was not found, but -1 is a valid index into >> the string. This is a potential source of hard-to-find bugs. > > Correct. But rather than removing it, it would be better to take a leaf out > of re.match's book and return None as the sentinel. That would eliminate > the "using -1 as a valid index" bug.
I disagree on both counts. >>> s = 'abc' >>> s[None:None] 'abc' Better IMO to just have the one non-redundant method that raises an exception rather than returning anything that could possibly be interpreted as a string index. -- https://mail.python.org/mailman/listinfo/python-list
