PEP 284, Integer for-loops (code bash?)

[Laura Creighton]

David Eppstein writes:

> Your ints module is nice, and I think if it were in the standard library
> I'd be a lot less motivated to push PEP 284.  But, the objection to it 
> will be that it only creates closed intervals, where other Python 
> objects create half-open ones and it would be nice to have a syntax that
> would allow any combination of open and closed interval endpoints.

I am not so certain of this.  I think that only some people think that
it would be nice to have a syntax that would allow any combination
of open and closed interval endpoints.  I don't.  I think that it
would have been nice if when Guido was designing the language he
used Haskall's syntax for loops.  But he didn't.  And I think that
the reason that no changes along these lines have happened despite
years of effort on the part of people who want changes is that this
is too hard a thing to retrofit a language with.  There are no 
changes that I can see that are not inferior to living with things
the way they are.  They flunk my personal elegance test.  Right now
I don't believe that it is possible to come around with one that is
elegant enough that I would support, because I think that we would
have found it already if it existed.  

(Now watch Guido pass the PEP tomorrow :-) )

Laura Creighton

By the way, for your students, what keeps you from doing this:

 import sys

 _indices = xrange(sys.maxint) 
 #a reusable index sequence, use with zip only, NOT with map

 ...

 for index, value in zip(_indices, someList):
          whatever_you_want()

I am assuming that your problem is that you want to teach algorithms to
your students and you don't want their brains getting derailed with
'what is a range function' and 'what is an open-interval' and the like.
zip is rather easy to understand.  Only the name is odd, but then map
is already taken.  But perhaps I have misunderstood your problem. 

Laura Creighton