Op 2/03/2022 om 15:58 schreef Larry Martell:
On Wed, Mar 2, 2022 at 9:37 AM Antoon Pardon<antoon.par...@vub.be> wrote:
If one list is empty I want just the other list. What I am doing is
building a list to pass to a mongodb query. If region is empty then I
want to query for just the items in the os list. I guess I can test
for the lists being empty, but I'd like a solution that handles that
as down the road there could be more than just 2 lists.
How about the following: Keep a list of your lists you want to permute over.
Like the following:
permutation_elements = [["Linux","Windows"],["us-east-1", "us-east-2"]]
permutation = itertools.product(*permutation_elements)
If you don't include the empty list, you will get more or less what you
seem to want.
But I need to deal with that case.
What does that mean? How does using the above method to produce the permutations
you want, prevent you from dealing with an empty list however you want when you
encounter them? Just don't add them to the permutation_elements.
I need to know what items are in which position. If sometimes the
regions are in one index and sometimes in another will not work for
me.
I am starting to suspect you didn't think this through. What you are telling
here
contradicts what you told earlier that if either list was empty, you just wanted
the other list. Because then you wouldn't know what items were in that list.
The only solution I can see now is that if a list is empty, you either add
[None] or
[""] to the permutation_elements (whatever suits you better) and then use
itertools.product
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