[Tutor] Help needed with script to batch-create shapefiles

[Jeff Shannon]

On Wed, 16 Feb 2005 21:37:10 +0000, Chris Bromley
<lgxjcb at nottingham.ac.uk> wrote:

> Any help would be greatly appreciated!

Others have already pointed out that we will have a hard time helping
without a bit more information.  But I've noticed something odd in
your code -- it probably doesn't have anything to do with your
problem, but it seems like an awkward idiom to me.

>     fc = fcs.next()
> 
>     while fc:
>         # [...]
>         fc = fcs.next()

This, it seems to me, is equivalent to (but less readable than) the following:

.    for fc in fcs:
.        # [...]

If you're going to do something with every member of a list, then it's
much more straightforward to use a for loop (which automatically
tracks the iteration) than to use a while loop and manually adjusting
the loop-controlling expression.

Actually, it occurs to me that this *might* cause a confusing result
in your code.  Presuming that fcs is a standard iterator (as your
usage of next() suggests), then calling next() on an exhausted
iterator will raise a StopIteration exception.  The for loop will
automatically handle that, but with your while loop it would be caught
by the following bare except statement.  That means that you'll run
(what I presume to be) your error-handling code even when you
successfully convert every member of fcs...

Jeff Shannon