Graded Homework 5

##### Grade: 4.1/5

Great work, @ptitchener & @jmorris1993! It's awesome that you abstracted a book to a vector of words and found similarity using that. Was there an inspiration for the project? The plot is an excellent final touch to the project. :smile:

As for the programming itself, there are a few things that needs to be addressed:
1. Most of your functions take in the string (`book`), but are meant to take in things like dictionaries representing the frequency of words, etc. Make sure you have a clear understanding of what your inputs and outputs are. If the docstring reads: `''' Takes in a list of words and returns a list of the first characters of each word '''`, then the parameters of your code should be a list of words and the output a list of the first characters.
2. Documentation - your docstrings are _excellent_. I enjoyed reading them and knew exactly what each function was going to do. However, there are some parts of the code that lack much needed documentation. I pointed a few out, so you should check them out under the "Files Changed" tab.

Once you've read the comments, make a comment to the pull request or send me/Diana an email, letting us know that you've checked them out. Afterwards, close the PR (and optionally delete the graded branch). Once we get your confirmation, we'll add **0.5** to your current grade. 

#### REMEMBER NOT TO MERGE THESE PRs!