looking for a neat solution to a nested loop problem

[Tom P]

On 08/06/2012 06:18 PM, Nobody wrote:
> On Mon, 06 Aug 2012 17:52:31 +0200, Tom P wrote:
>
>> consider a nested loop algorithm -
>>
>> for i in range(100):
>>       for j in range(100):
>>           do_something(i,j)
>>
>> Now, suppose I don't want to use i = 0 and j = 0 as initial values, but
>> some other values i = N and j = M, and I want to iterate through all
>> 10,000 values in sequence - is there a neat python-like way to this?
>
> 	for i in range(N,N+100):
> 	    for j in range(M,M+100):
> 	        do_something(i,j)
>
> Or did you mean something else?

no, I meant something else ..

   j runs through range(M, 100) and then range(0,M), and i runs through 
range(N,100) and then range(0,N)

.. apologies if I didn't make that clear enough.

>
> Alternatively:
>
> 	import itertools
>
> 	for i, j in itertools.product(range(N,N+100),range(M,M+100)):
> 	    do_something(i,j)
>
> This can be preferable to deeply-nested loops.
>
> Also: in 2.x, use xrange() in preference to range().
>