interesting exercise

[sherry]

On May 8, 9:31 am, Steven D'Aprano
<ste... at REMOVE.THIS.cybersource.com.au> wrote:
> On Mon, 07 May 2007 20:45:52 -0700, Michael Tobis wrote:
> > I have a reasonably elegant solution but it's a bit verbose (a couple
> > dozen lines which I'll post later if there is interest). Is there some
> > clever Pythonism I didn't spot?
>
> Peering into my crystal ball, I see that your algorithm does the wrong
> thing, and contains bugs too. You certainly don't need to partion the
> sequence into three sub-sequences, or do that trick with the metaclass,
> and it is more efficient to use list.extend() than sum.
>
> Hang on... stupid crystal ball... that's somebody else's code. Maybe you
> should just post your code here, so we can look at it?
>
> In the meantime, here's a simple generator to do permutations with
> repetition:
>
> def permute_with_repetitions(seq):
>     if len(seq) <= 1:
>         yield list(seq)
>     else:
>         for i, item in enumerate(seq):
>             for tail in permute_with_repetitions(seq[:i] + seq[i+1:]):
>                 yield [item] + tail
>
> It doesn't do a test for the sequence containing duplicates, and I leave
> it as anexerciseto do selections of fewer items.
>
> --
> Steven.

Dear Steven
 I ran into your message quite accidentally while researching about
some details on 'Exercise' and thought of sharing some of my
findings.
I've read at 'http://www.medical-health-care-information.com/Health-
living/exercise/index.asp
that Swimming, cycling, jogging, skiing, aerobic dancing, walking or
any of dozens of other activities can help your heart. Whether it's
included in a structured exercise program or just part of your daily
routine, all physical activity adds up to a healthier heart.
 I hope the above is of some help to you as well. Regards, Sherrybove.