Book Image

Functional Python Programming - Second Edition

Book Image

Functional Python Programming - Second Edition

Overview of this book

If you’re a Python developer who wants to discover how to take the power of functional programming (FP) and bring it into your own programs, then this book is essential for you, even if you know next to nothing about the paradigm. Starting with a general overview of functional concepts, you’ll explore common functional features such as first-class and higher-order functions, pure functions, and more. You’ll see how these are accomplished in Python 3.6 to give you the core foundations you’ll build upon. After that, you’ll discover common functional optimizations for Python to help your apps reach even higher speeds. You’ll learn FP concepts such as lazy evaluation using Python’s generator functions and expressions. Moving forward, you’ll learn to design and implement decorators to create composite functions. You'll also explore data preparation techniques and data exploration in depth, and see how the Python standard library fits the functional programming model. Finally, to top off your journey into the world of functional Python, you’ll at look at the PyMonad project and some larger examples to put everything into perspective.
Table of Contents (18 chapters)

Preface

Functional programming offers a variety of techniques for creating succinct and expressive software. While Python is not a purely functional programming language, we can do a great deal of functional programming in Python.

Python has a core set of functional programming features. This lets us borrow many design patterns and techniques from other functional languages. These borrowed concepts can lead us to create succinct and elegant programs. Python's generator expressions, in particular, negate the need to create large in-memory data structures, leading to programs that may execute more quickly because they use fewer resources.

We can’t easily create purely functional programs in Python. Python lacks a number of features that would be required for this. We don’t have unlimited recursion, for example, we don’t have lazy evaluation of all expressions, and we don’t have an optimizing compiler.

There are several key features of functional programming languages that are available in Python. One of the most important ones is the idea of functions being first-class objects. Python also offers a number of higher-order functions. The built-in map(), filter(), and functools.reduce() functions are widely used in this role, and less-obvious are functions such as sorted(), min(), and max().

We’ll look at the core features of functional programming from a Python point of view. Our objective is to borrow good ideas from functional programming languages and use those ideas to create expressive and succinct applications in Python.