[Python Edinburgh] How to do dynamic nesting of loops

[Magnus Hagdorn]

Hi Doug,
I think you will need to write an iterator which will return a tuple of 
indicies.

How do you decide on the number of nested loops?

Your program might looks something like

def myIterator(some,args):
   white some condition:
       do some stuff to figure out what to do
       yield (i,j,k,...)

for indicies in myIterator(...):
     do something with the tuple of indicies

Hope this gives you a starting point

Cheers
magi


On 18/11/14 12:08, Douglas Houston wrote:
> Hi all,
>
> I'm a bit stuck with this so maybe someone can help me.
>
> I'm writing a little program that needs to iterate through several
> nested 'for' loops. However, the number of loops (and therefore the
> depth of the nesting) cannot be predetermined.
>
> I've read that lots of nested loops are bad form anyway, and that "you
> should do it with functions instead".
>
> However I still can't work out how to set the number dynamically.
>
>
> for ((l=0; l<10; l++)); do
> ​ ​
>   for ((m=0; m<10; m++))
> ​;​
> do
> ​ ​
> for (n=0; n<10; n++)); do
> ​ ​
> something
> ​ that uses l, m and n​
>
>      done
>    done
> done
>
> So this is what it needs to look like if nest_depth=3
>
> But how do I write a program that iterates something
> ​ for nest_depth=4 (which in this case would use l, m, n and o)​, or any
> other number (which can't be predicted)?
>
> cheers,
> Doug
>
> PS I didn't write this in Python just for speed, but feel free to reply
> in Python if you want - the practice would be good for me.
>
>
> _______________________________________________
> Edinburgh mailing list
> Edinburgh at python.org
> https://mail.python.org/mailman/listinfo/edinburgh
>