Welcome to this lesson on combining functions in Python! By now, you should already be familiar with map, filter, reduce, and sorted from our previous lessons. Combining these functions lets you perform powerful data transformations concisely and readably.

By the end of this lesson, you'll understand how to combine multiple higher-order functions to perform complex data processing tasks. Specifically, we'll cover how to:

1. Use map, filter, and reduce together to perform cumulative operations on filtered data.
2. Combine map and sorted to achieve custom ordering of processed data.

These skills will help you write more efficient and readable code.

Let's solve a simple problem: finding the sum of the squares of even numbers from a list. We'll break this into three steps: