Book Image

Modern Python Cookbook - Second Edition

By : Steven F. Lott
Book Image

Modern Python Cookbook - Second Edition

By: Steven F. Lott

Overview of this book

Python is the preferred choice of developers, engineers, data scientists, and hobbyists everywhere. It is a great language that can power your applications and provide great speed, safety, and scalability. It can be used for simple scripting or sophisticated web applications. By exposing Python as a series of simple recipes, this book gives you insight into specific language features in a particular context. Having a tangible context helps make the language or a given standard library feature easier to understand. This book comes with 133 recipes on the latest version of Python 3.8. The recipes will benefit everyone, from beginners just starting out with Python to experts. You'll not only learn Python programming concepts but also how to build complex applications. The recipes will touch upon all necessary Python concepts related to data structures, object oriented programming, functional programming, and statistical programming. You will get acquainted with the nuances of Python syntax and how to effectively take advantage of it. By the end of this Python book, you will be equipped with knowledge of testing, web services, configuration, and application integration tips and tricks. You will be armed with the knowledge of how to create applications with flexible logging, powerful configuration, command-line options, automated unit tests, and good documentation.
Table of Contents (18 chapters)
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Unit testing with the pytest module

The pytest tool allows us to step beyond the examples used by doctest. Instead of using a subclass of unittest.TestCase, the pytest tool lets us use function definitions. The pytest approach uses Python's built-in assert statement, leaving the test case looking somewhat simpler. The pytest test design avoids using the complex mix of assertion methods.

The pytest tool is not part of Python; it needs to be installed separately. Use a command like this:

python -m pip install pytest

In this recipe, we'll look at how we can use pytest to simplify our test cases.

Getting ready

The ideas behind the Gherkin language can help to structure a test. In this test specification language, each scenario is described by GIVEN-WHEN-THEN steps. For this recipe, we have a scenario like this:

Scenario: Summary object can add values and compute statistics.
  Given a Summary object
  And numbers in the range 0 to 1000 (inclusive...