Book Image

Learning Concurrency in Python

By : Elliot Forbes
Book Image

Learning Concurrency in Python

By: Elliot Forbes

Overview of this book

Python is a very high level, general purpose language that is utilized heavily in fields such as data science and research, as well as being one of the top choices for general purpose programming for programmers around the world. It features a wide number of powerful, high and low-level libraries and frameworks that complement its delightful syntax and enable Python programmers to create. This book introduces some of the most popular libraries and frameworks and goes in-depth into how you can leverage these libraries for your own high-concurrent, highly-performant Python programs. We'll cover the fundamental concepts of concurrency needed to be able to write your own concurrent and parallel software systems in Python. The book will guide you down the path to mastering Python concurrency, giving you all the necessary hardware and theoretical knowledge. We'll cover concepts such as debugging and exception handling as well as some of the most popular libraries and frameworks that allow you to create event-driven and reactive systems. By the end of the book, you'll have learned the techniques to write incredibly efficient concurrent systems that follow best practices.
Table of Contents (20 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Future objects


Future objects are instantiated whenever we submit a task to an executor, such as how we submitted tasks to ThreadPoolExecutor in previous examples within this chapter. Future objects are objects that will, eventually, be given a value sometime in the future.

Methods in future objects

The future objects have the following methods with which we can access and modify them. Each of these methods will be covered in a full code sample further on in the chapter.

The result() method

The result() method gives us any returned values from the future object. This result method can be called like this:

futureObj.result(timeout=None)

By specifying the timeout parameter, we, basically, put a time limit on our future object. If the future object fails to complete in the given time frame, then a concurrent.futures. The timeout error is raised. This is quite useful, as it gives us more control in terms of capping the amount of time erroneous threads can execute for, and limiting the damage they...