[Python-ideas] [Python-Dev] Inclusive Range

[Carl M. Johnson]

I did some research before posting and saw that they talked about that
Dykstra paper on C2's page about zero indexing, and honestly, I count
it as a point in favor of starting with 1. Dykstra was a great
computer scientist but a terrible computer programmer (with the
exception of "Goto Considered Harmful" [a headline he didn't actually
give to his article]) in the sense that he understand how to do things
mathematically but not how to take into account the human factors in
such a way that one can get normal people to program well. His theory
that we should all be proving the correctness of our program is, to my
way of thinking, a crank's theory. If regular people can't be trusted
to program, they certainly can't be trusted to write correctness
proofs, which is a harder task, not a simpler one. Moreover this
ignores all of the stuff that Paul Graham would eventually say about
the joys of exploratory programming, or to give an earlier reference,
the need to build one to throw away as Brooks said. Proving
correctness presumes that you know what you want to program before you
start programming it, which is only rarely the case, mostly in the
computer science classroom. So, I don't consider Dykstra's expertise
to be worth relying in matters of programming, as distinct from
matters of computer science.

In the particular case, the correct way to represent an integer
between 2 and 12 wouldn't be a, b, c, or d. It would be i in range(2,
12) (if we were creating a new language that was 1 indexed and range
was likewise adjusted), the list [1] would be range(1), and the empty
list would be range(0), so the whole issue could be neatly
sidestepped. :-)

As for l == l[:x] + l[x:y] + l[y:] where y > x, I think a case can be
made that it would be less confusing as l == l[:x] + l[x+1:y] +
l[y+1:], since you don't want to start again with x or y. You just
ended at x. When you pick up again, you want to start at x+1 and y+1
so that you don't get the x-th and y-th elements again. ;-)

Of course this is speculation on my part. Maybe students of
programming find 1-indexing just as confusing as 0-indexing. Any
pedagogues want to chime in?

-- Carl Johnson