Make formatting and syntax changes.

I've made some basic syntax and formatting changes. It looks like I've changed a lot of stuff, but it really isn't that many changes. Some of the highlights:

  * I changed tabs to spaces. It is generally considered good practice when using Python to indent code using four spaces. I converted the code here. @CheyenneLaue remind me and I can show you how to set up your editor to use spaces instead of tabs by default.
  * Method names and local variables generally start with a lowercase letter. This helps to distinguish classes from instances of classes and other variables.
  * It is common to follow the method name immediately with the opening parenthesis. This is not true for all languages and styles, and certainly different people prefer different styles, but this is the most common style in Python.

### Using a pull request

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Typically you want method names to be verbs that indicate what action is to be performed. So, for instance, `move` instead of `movement`.