how to refactor nested for loop into smaller for loop assume each of them independent?

[BartC]

On 08/10/2016 11:03, Chris Angelico wrote:
> On Sat, Oct 8, 2016 at 8:58 PM, meInvent bbird <jobmattcon at gmail.com> wrote:
>> how to refactor nested for loop into smaller for loop assume each of them independent?
>>
>> because memory is not enough
>>
>> for ii in range(1,2000):
>>  for jj in range(1,2000):
>>   for kk in range(1,2000):
>>     print run(ii,jj,kk)
>
> Since you're using Python 2, you could try xrange instead of range.
> But it won't make a lot of difference. You're trying to call your run
> function 8,000,000,000 times... that is a *lot* of function calls.
> Consider a faster algorithm instead!

Printing even one character 8 billion times is likely to take quite a 
few hours too.

The OP's code however is a good demonstration of how crazy Python's 
original for-range loop was: you need to construct a list of N elements 
just to be able to count to N. How many years was it until xrange was 
introduced?

-- 
bartc