looking for a neat solution to a nested loop problem

Mon Aug 6 13:14:57 EDT 2012

On 08/06/2012 06:18 PM, Nobody wrote:
> On 2012年8月06日 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().
>