Book Image

Test-Driven Python Development

By : Siddharta Govindaraj
Book Image

Test-Driven Python Development

By: Siddharta Govindaraj

Overview of this book

This book starts with a look at the test-driven development process, and how it is different from the traditional way of writing code. All the concepts are presented in the context of a real application that is developed in a step-by-step manner over the course of the book. While exploring the common types of smelly code, we will go back into our example project and clean up the smells that we find. Additionally, we will use mocking to implement the parts of our example project that depend on other systems. Towards the end of the book, we'll take a look at the most common patterns and anti-patterns associated with test-driven development, including integration of test results into the development process.
Table of Contents (20 chapters)
Test-Driven Python Development
About the Author
About the Reviewers

Tying it all together

Let us tie this chapter together with a more complex example. The following is the code for the EmailAction class. This action sends an e-mail to the user when the rule is matched.

import smtplib
from email.mime.text import MIMEText

class EmailAction:
    """Send an email when a rule is matched"""
    from_email = "[email protected]"

    def __init__(self, to):
        self.to_email = to

    def execute(self, content):
        message = MIMEText(content)
        message["Subject"] = "New Stock Alert"
        message["From"] = "[email protected]"
        message["To"] = self.to_email
        smtp = smtplib.SMTP("")

The following is how the library works:

  1. We instantiate the SMTP class in the smtplib library, passing it the server we want to connect to. This returns the SMTP object.

  2. We call the send_message method on the SMTP object, passing in the e-mail message...