combinations of variable length nested lists

David Lees DavidL at raqia.com
Tue Aug 7 11:39:21 EDT 2001


If your list is called 'x' then len(x) will give you the number of
sublists at the top level, which what you are asking for.

david lees


Mark Robinson wrote:
> 
> I have hurt my brain (and those who are unfortunate to sit near me ;))
> trying to formulate an algorithm for the following problem. I am sure
> that someone here must be able to help me out, it seems such a trivial
> problem.
> 
> I have a nested list structure of the following format:
> [[2, 3, 4, 5],
>   [4, 5, 6, 7, 34],
>   [6, 2, 7, 4]
>   ....
>   ....
> ]
> 
> I want to generate all possible combinations that take one element from
> each nested list
> 
> i.e
> [2, 4, 6, ..., ...]
> [2, 4, 2, ..., ...]
> 
> If I knew the length of the outermost list beforehand I could hard code
> it as a series of nested for loops:
> 
> i.e
> 
> for i in list[0]:
>         for j in list[1]:
>                 for k in list[2]:
>                                 comb = [i, j, k]
> 
> but I can't figure a way to do this dynamically at runtime, when the
> outermost list is going to be variable in length.
> 
> If anyone can help, I'll be willing to sell my boss into slavery and
> give you all the profit ;)
> 
> Blobby



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