Iteration weirdness

[Dave Opstad]

I'm running into a strange behavior under Python 2.3.3:

------------------------------------------[color=blue][color=green][color=darkred]
>>> d = {-1: 'cv', -2: 'se', -3: 'se'}
>>> d[/color][/color][/color]
{-1: 'cv', -2: 'se', -3: 'se'}[color=blue][color=green][color=darkred]
>>> len(d)[/color][/color][/color]
3[color=blue][color=green][color=darkred]
>>> [d[-1], d[-2], d[-3]][/color][/color][/color]
['cv', 'se', 'se'][color=blue][color=green][color=darkred]
>>> [d[-1-i] for i in len(d)][/color][/color][/color]
Traceback (most recent call last):
File "<stdin>", line 1, in ?
TypeError: iteration over non-sequence
------------------------------------------

Can someone enlighten me as to why the list comprehension gives an
error, but the simple list construction case works fine?

Thanks for any help!
Dave Opstad

[Dave Opstad]

Re: Iteration weirdness

In article <dave.opstad-DE5822.10313102 062004@reader09 03.news.uu.net> ,
Dave Opstad <dave.opstad@ag famonotype.com> wrote:
[color=blue]
> I'm running into a strange behavior under Python 2.3.3:
>
> ------------------------------------------[color=green][color=darkred]
> >>> d = {-1: 'cv', -2: 'se', -3: 'se'}
> >>> d[/color][/color]
> {-1: 'cv', -2: 'se', -3: 'se'}[color=green][color=darkred]
> >>> len(d)[/color][/color]
> 3[color=green][color=darkred]
> >>> [d[-1], d[-2], d[-3]][/color][/color]
> ['cv', 'se', 'se'][color=green][color=darkred]
> >>> [d[-1-i] for i in len(d)][/color][/color]
> Traceback (most recent call last):
> File "<stdin>", line 1, in ?
> TypeError: iteration over non-sequence
> ------------------------------------------
>
> Can someone enlighten me as to why the list comprehension gives an
> error, but the simple list construction case works fine?
>
> Thanks for any help!
> Dave Opstad[/color]

Never mind, brain freeze on my part. Should have been:

[d[-1-i] for i in range(len(d))]

Sigh...sorry to bother everyone.

Dave