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

Traversing folders


When working with a path in the filesystem, it's common the need to find all files contained directly or in subfolders. Think about copying a directory or computing its size; in both cases, you will need to fetch the complete list of files included in the directory you want to copy, or for which you want to compute the size.

How to do it...

The steps for this recipe are as follows:

  1. The os.walk function in the os module is meant to traverse a directory recursively, its usage is not immediate, but with little effort, we can wrap it into a convenient generator of all the contained files:
import os

def traverse(path):
    for basepath, directories, files in os.walk(path):
        for f in files:
            yield os.path.join(basepath, f)
  1. Then, we can just iterate over traverse and apply whatever operation we need on top of it:
for f in traverse('.'):
    print(f)

How it works...

The os.walk function navigates the directory and all its subfolders. For each directory that it finds...