Bug in string.find; was: Re: Proposed PEP: New style indexing,was Re: Bug in slice type

[Paul Rubin]

Steve Holden <steve at holdenweb.com> writes:
> Of course. But onc you (sensibly) decide to use an "if" then there
> really isn't much difference between -1, None, () and sys.maxint as
> a sentinel value, is there?

Of course there is.  -1 is (under Python's perverse semantics) a valid
subscript.  sys.maxint is an artifact of Python's fixed-size int
datatype, which is fading away under int/long unification, so it's
something that soon won't exist and shouldn't be used.  None and ()
are invalid subscripts so would be reasonable return values, unlike -1
and sys.maxint.  Of those, None is preferable to () because of its
semantic connotations.