btw, mostly seems to run on python2!

I believe you intended to run in python3 based on your last cell.

changing maketrans and translate will have it run in python2.7

    table = string.maketrans('', '')  # remove punctuation from each word
    stripped = [w.translate(table, string.punctuation) for w in tokens]

Did you read the book on nltk before writing this project? Curious about background skill development to undertake this project.