All permutations from 2 lists

[gene heskett]

On Wednesday, 2 March 2022 10:49:11 EST Larry Martell wrote:
> On Wed, Mar 2, 2022 at 10:26 AM Antoon Pardon <antoon.pardon at vub.be> 
wrote:
> > Op 2/03/2022 om 15:58 schreef Larry Martell:
> > > On Wed, Mar 2, 2022 at 9:37 AM Antoon Pardon<antoon.pardon at 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
> 
> I found a way to pass this directly into the query:
> 
> def query_lfixer(query):
>     for k, v in query.items():
>         if type(v)==list:
>             query[k] = {"$in": v}
>     return query
> 
> self._db_conn[collection_name].find(query_lfixer(query))

I take it back, kmail5 had decided it was a different thread. My bad, no 
biscuit.

Cheers, Gene Heskett.
-- 
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