@treyhunner I merged your changes. I noticed one technical issue when running under 3.4.1.
This line below only outputs the words to stdout and does not place word into translated words dictionary:
translated_words = [print(words[spanish_word]) for spanish_word in sentence_words]
When I executed next line:
translated_words
the dictionary contains 6 elements with the value 'None'
Removing print correctly creates translated_words.