On 2012-08-06, Grant Edwards <invalid@invalid.invalid> wrote:
> On 2012-08-06, Tom P <werot...@freent.dd> wrote:
>> 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)
>
> 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)
--
Grant Edwards grant.b.edwards Yow! People humiliating
at a salami!
gmail.com
--
http://mail.python.org/mailman/listinfo/python-list
