looking for a neat solution to a nested loop problem

[Grant Edwards]

On 2012-08-06, Tom P <werotizy at freent.dd> wrote:

>>>> 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)
>>>
>>> In 2.x:
>>>
>>>      for i in range(M,100)+range(0,M):
>>>          for j in range(N,100)+range(0,N):
>>>              do_something(i,j)
>>>
>>> Dunno if that still works in 3.x.  I doubt it, since I think in 3.x
>>> range returns an iterator, not?
>>
>> Indeed it doesn't work in 3.x, but this does:
>>
>>      from itertools import chain
>>
>>      for i in chain(range(M,100),range(0,M)):
>>          for j in chain(range(N,100),range(0,N)):
>>              do_something(i,j)
>
>   ah, that looks good - I guess it works in 2.x as well?

I don't know.  Let me test that for you...

   $ python
   Python 2.6.8 (unknown, May 18 2012, 11:56:26) 
   [GCC 4.5.3] on linux2
   Type "help", "copyright", "credits" or "license" for more information.
   >>> from itertools import chain
   >>> for i in chain(range(0,5),range(5,10)):
   ...   print i
   ... 
   0
   1
   2
   3
   4
   5
   6
   7
   8
   9
   >>> 

Yes, it works in 2.x as well.

-- 
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