Welcome! Today, we'll learn about the Functor Design Pattern in Python. You might wonder, what is a Functor, and why should you care? Functors come from functional programming, making your code more modular and easier to understand.

Our goal is to understand functors and use them in Python to manage and transform values neatly. By the end, you'll know how to create and use functors effectively.

A Functor is a design pattern for mapping or transforming data. Think of it as a container for a value that can apply a function to the value inside. Imagine you have a box with a toy inside, and you want to paint the toy. You don't need to open the box; you apply the paint directly to the toy inside. That's what a Functor does—it applies functions to values without opening the "box."

In simple terms, a Functor:

1. Holds a value.
2. Provides a map method to apply a function to the value inside.

Let's create a basic Functor class in Python using type annotations.