Setting element of array from Twig & Accessing array values using array key from Twig

{% set items_0 = { 'apple': 'fruit', 'orange': 'fruit1', 'peugeot': 'nown' } %}
{% set arr = {} %}

{% for key,value in items_0 %}
    {# {{ key ~ ":" ~ value }} #}
{% set arr = arr|merge({ (key) : value }) %}
    {{ arr[key] }}
{% endfor %}
=============

{% for key,value in arr %}
    {{ key ~ ":" ~ value }}
{% endfor %}
===============

http://twig.sensiolabs.org/doc/filters/merge.html