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Groups > comp.lang.python > #84931

Re: Create dictionary based of x items per key from two lists

References <0dddee06-233b-436a-be48-3c16e62c1718@googlegroups.com>
Date 2015-01-31 13:38 +1100
Subject Re: Create dictionary based of x items per key from two lists
From Chris Angelico <rosuav@gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.18327.1422671928.18130.python-list@python.org> (permalink)

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On Sat, Jan 31, 2015 at 1:27 PM,  <rajanbond@gmail.com> wrote:
> l1 =  ["a","b","c","d","e","f","g","h","i","j"]
> l2 = ["aR","bR","cR"]
>
> l2 will always be smaller or equal to l1
>
> numL1PerL2 = len(l1)/len(l2)
>
> I want to create a dictionary that has key from l1 and value from l2 based on numL1PerL2
>
> So
>
> {
> a:aR,
> b:aR,
> c:aR,
> d:bR,
> e:bR,
> f:bR,
> g:cR,
> h:cR,
> i:cR,
> j:cR
> }
>
> So last item from l2 is key for remaining items from l1

So the Nth element of l1 will always be paired with the
(N/numL1PerL2)th element of l2 (with the check at the end)? Seems easy
enough.

dups = len(l1)/len(l2)
l2.append(l2[-1])
result = {x:l2[i/dups] for i,x in enumerate(l1)}

This mutates l2 for convenience, but you could also adjust the index
to take care of the excess. As a one-liner:

result = {x:l2[min(i/(len(l1)/len(l2)),len(l2)-1)] for i,x in enumerate(l1)}

But the one-liner is not better code :)

ChrisA

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Thread

Create dictionary based of x items per key from two lists rajanbond@gmail.com - 2015-01-30 18:27 -0800
  Re: Create dictionary based of x items per key from two lists Chris Angelico <rosuav@gmail.com> - 2015-01-31 13:38 +1100
  Re: Create dictionary based of x items per key from two lists Jason Friedman <jsf80238@gmail.com> - 2015-01-31 19:38 -0700
    Re: Create dictionary based of x items per key from two lists rajanbond@gmail.com - 2015-02-02 10:48 -0800
    Re: Create dictionary based of x items per key from two lists rajanbond@gmail.com - 2015-02-02 11:00 -0800
  Re: Create dictionary based of x items per key from two lists Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-02-01 03:06 +0000
  Re: Create dictionary based of x items per key from two lists Chris Angelico <rosuav@gmail.com> - 2015-02-01 14:22 +1100
    Re: Create dictionary based of x items per key from two lists Grant Edwards <invalid@invalid.invalid> - 2015-02-01 18:14 +0000
      Re: Create dictionary based of x items per key from two lists Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-02-01 18:49 +0000
      Re: Create dictionary based of x items per key from two lists mm0fmf <none@mailinator.com> - 2015-02-01 18:52 +0000
      Re: Create dictionary based of x items per key from two lists Ian Kelly <ian.g.kelly@gmail.com> - 2015-02-01 12:36 -0700
        Re: Create dictionary based of x items per key from two lists wxjmfauth@gmail.com - 2015-02-02 23:13 -0800
      Re: Create dictionary based of x items per key from two lists Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-02-01 20:28 +0000
      Re: Create dictionary based of x items per key from two lists Chris Angelico <rosuav@gmail.com> - 2015-02-02 07:33 +1100
  Re: Create dictionary based of x items per key from two lists Ian Kelly <ian.g.kelly@gmail.com> - 2015-02-01 11:51 -0700

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