Book Image

Modern Python Standard Library Cookbook

By : Alessandro Molina
Book Image

Modern Python Standard Library Cookbook

By: Alessandro Molina

Overview of this book

The Python 3 Standard Library is a vast array of modules that you can use for developing various kinds of applications. It contains an exhaustive list of libraries, and this book will help you choose the best one to address specific programming problems in Python. The Modern Python Standard Library Cookbook begins with recipes on containers and data structures and guides you in performing effective text management in Python. You will find Python recipes for command-line operations, networking, filesystems and directories, and concurrent execution. You will learn about Python security essentials in Python and get to grips with various development tools for debugging, benchmarking, inspection, error reporting, and tracing. The book includes recipes to help you create graphical user interfaces for your application. You will learn to work with multimedia components and perform mathematical operations on date and time. The recipes will also show you how to deploy different searching and sorting algorithms on your data. By the end of the book, you will have acquired the skills needed to write clean code in Python and develop applications that meet your needs.
Table of Contents (21 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Generic functions


Generic functions are one of my favorite features of the standard library. Python is a very dynamic language and through duck-typing, you will frequently be able to write code that works in many different conditions (it doesn't matter if you receive a list or a tuple), but in some cases, you will really need to have two totally different code bases depending on the received input.

For example, we might want to have a function that prints content of the provided dictionary in a human-readable format, but we want it also to work properly on lists of tuples and report errors for unsupported types.

How to do it...

The functools.singledispatch decorator allows us to implement a generic dispatch based on argument type:

from functools import singledispatch

@singledispatch
def human_readable(d):
    raise ValueError('Unsupported argument type %s' % type(d))

@human_readable.register(dict)
def human_readable_dict(d):
    for key, value in d.items():
        print('{}: {}'.format(key...