As V. Melnychuk mentioned, JSON is a good option, just remember to import the "json" module first:
require "json"
dictionary.to_json
in general, you can retreive a readable string version of an object by calling inspect on it:
dictionary.inspect
finally, there is a "pp" module to pretty-print variable (pretty much like the pprint module in python):
require "pp"
pp dictionary
Hope it helps !