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 14. The PyMonad Library

A monad allows us to impose an order on an expression evaluation in an otherwise lenient language. We can use a monad to insist that an expression such asa + b + c is evaluated in left-to-right order. This can interfere with the compiler's ability to optimize expression evaluation. This is necessary, for example, when we want files to have their content read or written in a specific order: a monad assures that the read() and write() functions are evaluated in a particular order.

Languages that are lenient and have optimizing compilers benefit from monads imposing order on the evaluation of expressions. Python, for the most part, is strict and does not optimize. There are no practical requirements for monads.

However, the PyMonad package contains more than just monads. There are a number of functional programming features that have a distinctive implementation. In some cases, the PyMonad module can lead to programs which are more succinct and expressive than...