interesting exercise

[castironpi at gmail.com]

On May 7, 10:45 pm, Michael Tobis <mto... at gmail.com> wrote:
> I want a list of all ordered permutations of a given length of a set
> of tokens. Each token is a single character, and for convenience, they
> are passed as a string in ascending ASCII order.
>
> For example
>
> permute("abc",2)
>
> should return ["aa","ab","ac","ba","bb","bc","ca","cb","cc"]
>
> and permute("13579",3) should return a list of 125 elements
> ["111","113", ... ,"997","999"]
>
> permute("axc",N) or permute("2446",N) should raise ValueError as the
> alphabet is not strictly sorted.
>
> 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?
>
> thanks
> mt

Post yours.