Book Image

Mastering Python

By : Rick van Hattem
Book Image

Mastering Python

By: Rick van Hattem

Overview of this book

Python is a dynamic programming language. It is known for its high readability and hence it is often the first language learned by new programmers. Python being multi-paradigm, it can be used to achieve the same thing in different ways and it is compatible across different platforms. Even if you find writing Python code easy, writing code that is efficient, easy to maintain, and reuse is not so straightforward. This book is an authoritative guide that will help you learn new advanced methods in a clear and contextualised way. It starts off by creating a project-specific environment using venv, introducing you to different Pythonic syntax and common pitfalls before moving on to cover the functional features in Python. It covers how to create different decorators, generators, and metaclasses. It also introduces you to functools.wraps and coroutines and how they work. Later on you will learn to use asyncio module for asynchronous clients and servers. You will also get familiar with different testing systems such as py.test, doctest, and unittest, and debugging tools such as Python debugger and faulthandler. You will learn to optimize application performance so that it works efficiently across multiple machines and Python versions. Finally, it will teach you how to access C functions with a simple Python call. By the end of the book, you will be able to write more advanced scripts and take on bigger challenges.
Table of Contents (22 chapters)
Mastering Python
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
6
Generators and Coroutines – Infinity, One Step at a Time
Index

Sharing data between processes


This is really the most difficult part about multiprocessing, multithreading, and distributed programming - which data to pass along and which data to skip. The theory is really simple, however: whenever possible don't transfer any data, don't share anything, and keep everything local. Essentially the functional programming paradigm, which is why functional programming mixes really well with multiprocessing. In practice, regrettably, this is simply not always possible. The multiprocessing library has several options to share data: Pipe, Namespace, Queue, and a few others. All these options might tempt you to share your data between the processes all the time. This is indeed possible, but the performance impact is, in many cases, more than what the distributed calculation will offer as extra power. All data sharing options come at the price of synchronization between all processing kernels, which takes a lot of time. Especially with distributed options, these...