Book Image

Modern Python Cookbook

Book Image

Modern Python Cookbook

Overview of this book

Python is the preferred choice of developers, engineers, data scientists, and hobbyists everywhere. It is a great scripting language that can power your applications and provide great speed, safety, and scalability. By exposing Python as a series of simple recipes, you can gain insight into specific language features in a particular context. Having a tangible context helps make the language or standard library feature easier to understand. This book comes with over 100 recipes on the latest version of Python. The recipes will benefit everyone ranging from beginner to an expert. The book is broken down into 13 chapters that build from simple language concepts to more complex applications of the language. The recipes will touch upon all the necessary Python concepts related to data structures, OOP, functional programming, as well as statistical programming. You will get acquainted with the nuances of Python syntax and how to effectively use the advantages that it offers. You will end the book equipped with the knowledge of testing, web services, and configuration and application integration tips and tricks. The recipes take a problem-solution approach to resolve issues commonly faced by Python programmers across the globe. You will be armed with the knowledge of creating applications with flexible logging, powerful configuration, and command-line options, automated unit tests, and good documentation.
Table of Contents (18 chapters)
Title Page
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Mocking external resources


The Testing things that involve dates or times and Testing things that involve randomness recipes show techniques for mocking relatively simple objects. In the case of the Testing things that involve dates or timesrecipe, the object being mocked is essentially stateless, and a single return value works nicely. In the Testing things that involve randomness recipe, the object has a state change, but the state change does not depend on any input arguments.

In these simpler cases, a test provides a series of requests to an object. Mock objects can be built which are based on a known and carefully planned sequence of state changes. The test case follows the object's internal state changes precisely. This is sometimes called white box testing because the implementation details of the object under test are required to define the test sequence and the mock objects.

In some cases, however, a test scenario may not involve a well-defined sequence of state changes. The unit...