In both unittest and pytest, when a test function hits a failing assert, the test stops and is marked as a failed test.

What if you want to keep going, and check more things?

Python's unittest introduced subtests in Python 3.4.

But really, what are they? When could you use them?

That's what Paul Ganssle and I will be talking about today.

Special Guest: Paul Ganssle.

Sponsored By:

• ConfigCat.com: Release features faster with less risk with ConfigCat feature flags. Promo Code: TESTANDCODE
• WeeklyPythonExercise.com: Become a more fluent Python developer.

Links:

• Subtests in Python — Paul's article on subtests
• subtests in unittest - Python docs
• pytest-subtests: plugin to support subtests in pytest
• pytest-check: A pytest plugin that allows multiple failures per test.

Django supports testing out of the box with some cool extensions to unittest. However, many people are using pytest for their Django testing, mostly using the pytest-django plugin.

Adam Parkin, who is known online as CodependentCodr, joins us to talk about migrating an existing Django project from unittest to pytest. Adam tells us just how easy this is.

Special Guest: Adam Parkin.

Sponsored By:

• PyCharm Professional: Try PyCharm Pro for 4 months and learn how PyCharm will save you time. Promo Code: TESTANDCODE22

Links:

• Django Tutorial, on testing
• The Django docs on testing & the test database
• The Django docs on the TestCase class
• pytest-django docs

Financial services have their own unique testing development challenges. But they also have lots of the same challenges as many other software projects.

Eric Bergemann joins Brian Okken to discuss:

Special Guest: Eric Bergemann.

Sponsored By:

• ConfigCat.com: Release features faster with less risk with ConfigCat feature flags. Promo Code: TESTANDCODE

Links:

• Paragon
• The Phoenix Project: A Novel about IT, DevOps, and Helping Your Business Win

Apache Spark is a unified analytics engine for large-scale data processing.

Johnathan Rioux, author of "PySpark in Action", joins the show and gives us a great introduction of Spark and PySpark to help us decide how to get started and decide whether or not to decide if Spark and PySpark are right you.

Special Guest: Jonathan Rioux.

Sponsored By:

• PyCharm Professional: Try PyCharm Pro for 4 months and learn how PyCharm will save you time. Promo Code: TESTANDCODE22

Links:

• PySpark in Action
• Spark
• PySpark documentation
• Joel Grus, livecoding

Hypothesis is the Python tool used for property based testing.

In this episode Alexander Hultnér introduces us to property based testing in Python with Hypothesis.

Some topics covered:

Special Guest: Alexander Hultnér.

Sponsored By:

• PyCharm Professional: Try PyCharm Pro for 4 months and learn how PyCharm will save you time. Promo Code: TESTANDCODE22

Links:

• Hypothesis home
• Hypothesis docs
• Test Fast, Fix More - Property based testing with Hypothesis by Alexander Hultnér - YouTube
• Quickcheck, Grandfather of property based testing
• Beyond Unit Tests, Hillel Wayne, PyCon 2018
• Better Testing With Less Code, Matt Bachmann, PyCon 2016
• Choosing properties for property-based testing (F#)
• schemathesis: Hypothesis + Open API / Swagger for testing web applications

IDEs can help people with automated testing.

In this episode, Paul Everitt and Brian discuss ways IDEs can encourage testing and make it easier for everyone, including beginners. We discuss features that exist and are great, as well as what is missing.

The conversation also includes topics around being welcoming to new contributors for both open source and professional projects.

We talk about a lot of topics, and it's a lot of fun. But it's also important. Because IDEs can make testing

Some topics discussed:

Special Guest: Paul Everitt.

Links:

• Python Testing with pytest — The pytest book
• PyCharm
• PyCharm pro
• episode 54: Python 1994 - Paul Everitt
• pytest-xdist

The Test Anything Protocol, or TAP, is a way to record test results in a language agnostic way, predates XML by about 10 years, and is still alive and kicking.

Matt Layman has contributed to Python in many ways, including his educational newsletter, and his Django podcast, Django Riffs.

Matt is also the maintainer of tap.py and pytest-tap, two tools that bring the Test Anything Protocol to Python.

In this episode, Matt and I discuss TAP, it's history, his involvement, and some cool use cases for it.

Special Guest: Matt Layman.

Sponsored By:

• PyCharm Professional: Try PyCharm Pro for 4 months and learn how PyCharm will save you time. Promo Code: TESTANDCODE22

Links:

• mattlayman.com
• Django Riffs, a podcast for learning Django · Matt Layman
• Test Anything Protocol
• pytest-tap: Test Anything Protocol (TAP) reporting plugin for pytest
• tappy - TAP tools for Python

pytest is awesome by itself. pytest + plugins is even better.

Some of the plugins discussed (we also mention a few plugins related to some on this list):

Honorable mention:

Special Guest: Anthony Sottile.

Sponsored By:

• Oxylabs: Visit oxylabs.io/testandcode to find out more about their services and to apply for a free trial of their Next-Generation Residential Proxies.
• Springboard: Check out Springboards machine learning engineering career track. Promo Code: AISPRINGBOARD

Links:

• PyPI Download Stats
• Top PyPI Packages: A monthly dump of the 4,000 most-downloaded packages from PyPI
• Test & Code 25: Selenium, pytest, Mozilla – Dave Hunt
• pre-commit

Django is without a doubt one of the most used web frameworks for Python. Lacey Williams Henschel is a Django consultant and has joined me to talk about Django, the Django community, and so much more.

Topics:

Special Guest: Lacey Williams Henschel.

Sponsored By:

• Raygun: Detect, diagnose, and destroy Python errors that are affecting your customers. With smart Python error monitoring software from Raygun.com, you can be alerted to issues affecting your users the second they happen.

Links:

• Django
• Django Girls
• Django Girls Tutorial
• DjangoCon US 2020
• Django: Under the Hood
• PyData
• PyCascades
• Django REST framework
• pytest-django
• Wagtail CMS - Django Content Management System

Harry Percival has completed his second book, "Architecture Patterns with Python".
 So of course we talk about the book, also known as "Cosmic Python".
 We also discuss lots of testing topics, especially related to larger systems and systems involving third party interfaces and APIs.

Topics 

• Harry's new book, "Architecture Patterns with Python". a.k.a. Cosmic Python 
• TDD : Test Driven Development
• Test Pyramid
• Tradeoffs of different architectural choices
• Mocks and their pitfalls
• Avoiding mocks
• Separating conceptual business logic
• Dependency injection
• Dependency inversion
• Identifying external dependencies
• Interface adapters to mimize the exposed surface area of external dependencies
• London School vs Classic/Detroit School of TDD
• Testing strategies for testing external REST APIs

Links:

• Cosmic Python - Simple Patterns for Building Complex Applications
• Architecture Patterns with Python - on Amazon
• Harry Percival (@hjwp) / Twitter
• Bob Gregory (@bob_the_mighty) / Twitter
• vcrpy · PyPI
• Writing tests for external API calls
• Stop Using Mocks (for a while) - Harry's PyCon talk