PEP 308: "then" "else" for deprecating "and" "or" side effects

[Terry Reedy]

"Tim Peters" <tim.one at comcast.net> wrote in message
news:mailman.1045800478.31116.python-list at python.org...

> [Mike Orr]
> > Python has always been great in adding, not every feature,
> > but a few well-chosen features that have wide applicability.
>
> The perceived lack of which (wide applicability) being why Guido
rejected
> his implementation of conditionals last time around.  I can't say
I've seen
> many compelling use cases in this incarnation of the beast (and, no,
min and
> max aren't compelling -- although they would be if they weren't
built in
> already -- if "functions like that" were common, I'd expect to see
some
> examples other than min and max <wink>).

If Python did all looping by recursion, there would be many more
possible uses (though no more necessity) for a ternary conditional:

def fact(n): return n and n*fact(n-1) or 1
# needs a negative arg guard

def sum(seq): return (len(seq) or 0) and seq(-1) + sum(:-1)
# works better with head/tail linked list so no copying of tail

But Python does have for, while, map, filter, reduce, file.readlines,
(new) itertools, etc. in addition to min and max.

Terry J. Reedy