Combining arbitrary lists

[Steve Holden]

Thorsten Kampe wrote:

> * Nick (2004-11-15 04:28 +0100)
> 
>>Given that
>>
>>n = [ [1, 2, 3], [4, 5, 6], [7, 8] ]
>>
>>then the following code produces what I expect
>>
>>for x in n[0]:
>>   for y in n[1]:
>>     for z in n[2]:
>>       print [x, y, z]
>>
>>--output--
>>[1, 4, 7]
>>[1, 4, 8]
>>[1, 5, 7]
>>[1, 5, 8]
>>  ...
>>[3, 6, 8]
>>--      --
>>
>>How can I do this for an arbirary length of n?
> 
> 
> This is the Cartesian product of three sets. Have a look at
> http://www.thorstenkampe.de/python/utils.py:
> 
> def cartes(seq0, seq1, modus = 'pair'):
>     """ return the Cartesian Product of two sequences """
>     if   modus == 'pair':
>         return [[item0, item1] for item0 in seq0 for item1 in seq1]
>     elif modus == 'triple':
>         return [item0 + [item1] for item0 in seq0 for item1 in seq1]
> 
> Then you would generate your output like this:
> 
>>>>cartes(cartes([1, 2, 3], [4, 5, 6]), [7, 8], 'triple')

I think the point of the question was to act on an arbitrary number of 
length-3 lists.

regards
  Steve
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