title: Trying to use os.walk to and FreqDist for all files in a directory and subdirectories
body: <p>I'm trying to use NLTK to get the most common words used in an entire directory consisting of around a dozen sub-directories with around a dozen to two-dozen text files in each. I'm using the os.walk function and NLTK's FreqDist, but my code doesn't seem to work. I've tried lots but can't get it to run. Any help would be greatly appreciated!!</p>