crista/exercises-in-programming-style — pull request #15 by davidfstr (2014-01-06 05:07:14+00:00)
Title: things: Refactor.

Specifically:
* Remove dead assignments to `_data` and `_stop_words`.
* Convert `_word_freqs` from class field to instance field to avoid side effects.
* Remove no-op call `''.join(self._data)` because `self._data` is guaranteed to be a string.