The closest I’ve found to a ruby equivalent for python’s dict comprehension.
# python
from pprint import pprint
import string
pprint({i: string.lowercase[i] for i in range(len(string.lowercase))})
# ruby
require 'pp'
lowercase = ('a'..'z').map { |v| v }
pp Hash[lowercase.each_with_index.map { |v, i| [i, v] }]