Hands-On Software Engineering with Python

Functional programming

Functional Programming (FP) is a development approach centered around the concept of passing control through a series of pure functions, and avoiding shared state and mutable data structures. That is, the majority of any real functionality in FP is wrapped in functions that will always return the same output for any given input, and don't modify any external variables. Technically, a pure function should not write data to anywhere—neither logging to a console or file, nor writing to a file—and how the need for that sort of output is accommodated is a discussion well outside the scope of this book.

The following is the same functionality that was in the previous two examples, but written using a Functional Programming ...