[Python Edinburgh] How to do dynamic nesting of loops

[Tom Dalton]

You can use itertools.product to simplify this even further. If the
max-count for each loop is the same then you can do:

import itertools
N=3
for x in itertools.product(range(10), repeat=N):
    print x

If the max-count is different you can specify the range for each part
separately:

for x in itertools.product(range(2), range(3), range(4)):
    print x

Ref https://docs.python.org/2/library/itertools.html#itertools.product

Tom

On 18 November 2014 13:04, Andre Engelbrecht <litt.fire.sa at gmail.com> wrote:

> Something like this maybe?
>
> https://gist.github.com/andrewebdev/e3a979cfb46380884f3a
>
> Andre Engelbrecht
> Web Developer/Designer
> http://andre.engelbrechtonline.net
> http://www.tehnode.co.uk
>
> Too brief? Here's why! http://emailcharter.org
>
> On Tue, Nov 18, 2014 at 12:56 PM, Kenny Erasmuson <
> kennyerasmuson at gmail.com> wrote:
>
>> It sounds like some kind of recursive function may be needed here.
>> However, it also looks like the 'inner' most function call will then be
>> operating on a variable number of parameters (e.g. l, m and n in your
>> example, but it could be l, m, n, k, z, etc). Is that right?
>>
>> On 18 November 2014 12:53, Tom Dalton <tom.dalton at fanduel.com> wrote:
>>
>>> Hey Doug,
>>>
>>> There are a few ways you could do this, but it would be helpful if you
>>> could give a little more context on where you get l,m and n from and where
>>> the limit (10) comes from for each (or how it's determined). Also, what
>>> does the thing that uses those variables look like? Is it separate function
>>> calls, or a function that takes a list of arguments, or something else?
>>>
>>> Cheers,
>>>
>>> Tom
>>>
>>> On 18 November 2014 12:08, Douglas Houston <
>>> douglasrhouston at googlemail.com> wrote:
>>>
>>>> Hi all,
>>>>
>>>> I'm a bit stuck with this so maybe someone can help me.
>>>>
>>>> I'm writing a little program that needs to iterate through several
>>>> nested 'for' loops. However, the number of loops (and therefore the depth
>>>> of the nesting) cannot be predetermined.
>>>>
>>>> I've read that lots of nested loops are bad form anyway, and that "you
>>>> should do it with functions instead".
>>>>
>>>> However I still can't work out how to set the number dynamically.
>>>>
>>>>
>>>> for ((l=0; l<10; l++)); do
>>>> ​ ​
>>>>  for ((m=0; m<10; m++))
>>>> ​;​
>>>> do
>>>>
>>>> ​ ​
>>>> for (n=0; n<10; n++)); do
>>>>
>>>> ​ ​
>>>> something
>>>> ​ that uses l, m and n​
>>>>
>>>>     done
>>>>   done
>>>> done
>>>>
>>>> So this is what it needs to look like if nest_depth=3
>>>>
>>>> But how do I write a program that iterates something
>>>> ​ for nest_depth=4 (which in this case would use l, m, n and o)​, or
>>>> any other number (which can't be predicted)?
>>>>
>>>> cheers,
>>>> Doug
>>>>
>>>> PS I didn't write this in Python just for speed, but feel free to reply
>>>> in Python if you want - the practice would be good for me.
>>>>
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>>>>
>>>
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>>
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