reinhold birkenfeld

Well, nobody stops you from posting this on python-dev and be screamed
at by Guido...

just-kidding-ly
Reinhold

terry reedy

I agree in this sense: the use of any int as an error return is an
unPythonic *nix-Cism, which I believe was copied therefrom. Str.find is
redundant with the Pythonic exception-raising str.index and I think it
should be removed in Py3.

Therefore, I think changing it now is untimely and changing the language
because of it backwards.

Terry J. Reedy

paul rubin

"Terry Reedy" <tjreedy@udel.edu> writes:

I like having it available so you don't have to clutter your code with
try/except if the substring isn't there. But it should not return a
valid integer index.

terry reedy

The try/except pattern is a pretty basic part of Python's design. One
could say the same about clutter for *every* function or method that raises
an exception on invalid input. Should more or even all be duplicated? Why
just this one?


Terry J. Reedy

torsten bronger

Hallöchen!

"Terry Reedy" <tjreedy@udel.edu> writes:


Granted, try/except can be used for deliberate case discrimination
(which may even happen in the standard library in many places),
however, it is only the second most elegant method -- the most
elegant being "if". Where "if" does the job, it should be prefered
in my opinion.

Tschö,
Torsten.

--
Torsten Bronger, aquisgrana, europa vetus ICQ 264-296-646

paul rubin

"Terry Reedy" <tjreedy@udel.edu> writes:

Someone must have thought str.find was worth having, or else it
wouldn't be in the library.

raymond hettinger

<klingon> Bah!
</klingon>

The pythonic way to handle negative slicing is to use reversed(). The
principle is that the mind more easily handles this in two steps,
specifying the range a forward direction, and then reversing it.

IOW, it is easier to identify the included elements and see the
direction of:

reversed(xrange(1, 20, 2))

than it is for:

xrange(19, -1, -2)

See PEP 322 for discussion and examples:
http://www.python.org/peps/pep-0322.html

Raymond

terry reedy

Well, Guido no longer thinks it worth having and emphatically agreed that
it should be added to one of the 'To be removed' sections of PEP 3000.

Terry J. Reedy

steve holden

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?

Which is what I've been trying to say all along.

regards
Steve
--
Steve Holden +44 150 684 7255 +1 800 494 3119
Holden Web LLC http://www.holdenweb.com/

steve holden

If you want an exception from your code when 'w' isn't in the string you
should consider using index() rather than find.

Otherwise, whatever find() returns you will have to have an "if" in
there to handle the not-found case.

This just sounds like whining to me. If you want to catch errors, use a
function that will raise an exception rather than relying on the
invalidity of the result.

regards
Steve
--
Steve Holden +44 150 684 7255 +1 800 494 3119
Holden Web LLC http://www.holdenweb.com/