Book Image

Functional Python Programming - Second Edition

By : Steven F. Lott
Book Image

Functional Python Programming - Second Edition

By: Steven F. Lott

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 (22 chapters)
Title Page
Packt Upsell

Chapter 3. Functions, Iterators, and Generators

The core of functional programming is the use of pure functions to map values from the input domain to the output range. A pure function has no side effects, a relatively easy threshold for us to achieve in Python.

Avoiding side effects can lead to reducing any dependence on variable assignment to maintain the state of our computations. We can't purge the assignment statement from the Python language, but we can reduce our dependence on stateful objects. This means choosing among the available Python built-in functions and data structures to select those that don't require stateful operations.

This chapter will present several Python features from a functional viewpoint, as follows:

  • Pure functions, free of side effects
  • Functions as objects that can be passed as arguments or returned as results
  • The use of Python strings using object-oriented suffix notation and prefix notation
  • Using tuples and named tuples as a way to create stateless objects
  • Using...