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

Complex design considerations

In the case of our data cleanup, the simplistic removal of stray characters may not be sufficient. When working with the geolocation data, we may have a wide variety of input formats that include simple degrees (37.549016197), degrees and minutes (37° 32.94097′), and degrees-minutes-seconds (37° 32′ 56.46″). Of course, there can be even more subtle cleaning problems: some devices will create an output with the Unicode U+00BA character, º, instead of the similar-looking degree character, °, which is U+00B0.

For this reason, it is often necessary to provide a separate cleansing function that's bundled in with the conversion function. This function will handle the more sophisticated conversions required by inputs that are as wildly inconsistent in format as latitudes and longitudes.

How can we implement this? We have a number of choices. Simple higher-order functions are a good choice. A decorator, on the other hand, doesn't work out terribly well. We'll look at...