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

Running system commands


In some cases, especially when writing system tools, there might be work that you need to offload to another command. For example, if you have to decompress a file, in many cases, it might make sense to offload the work to gunzip/zip commands instead or trying to reproduce the same behavior in Python.

While there are many ways in Python to handle this work, they all have subtle differences that might make the life of any developer hard, so it's good to have a generally working solution that tackles the most common issues.

How to do it...

Perform the following steps:

  1. Combining the subprocess and shlex modules allows us to build a solution that is reliable in most cases:
import shlex
import subprocess

def run(command):
    try:
        result = subprocess.check_output(shlex.split(command), 
                                         stderr=subprocess.STDOUT)
        return 0, result
    except subprocess.CalledProcessError as e:
        return e.returncode, e.output
  1. It's easy...