What Is A None Value

Martijn's answer explains what None is in Python, and correctly states that the book is misleading. Since Python programmers as a rule would never say

Assigning a value of None to a variable is one way to reset it to its original, empty state.

it's hard to explain what Briggs means in a way which makes sense and explains why no one here seems happy with it. One analogy which may help:

In Python, https://wingirls.wtf/manyvids/ variable names are like stickers put on objects. Every sticker has a unique name written on it, and it can only be on one object at a time, but you could put more than one sticker on the same object, if you wanted to. When you write

you put the sticker "F" on a string object "fork". If you then write

you move the sticker to the None object.

What Briggs is asking you to imagine is that you didn't write the sticker "F", there was already an F sticker on the None, and all you did was move it, from None to "fork". So when you type F = None, you're "reset[ting] it to its original, empty state", if we decided to treat None as meaning empty state.