Understanding Regular Expressions and Testing Methodologies in Python

What is behavior-driven development, and how does it work alongside test-driven development? How do you communicate requirements between teams in an organization? Christopher Trudeau is back on the show this week, bringing another batch of PyCoder’s Weekly articles and projects.

In this episode, we expand on our software testing discussion from two weeks ago by adding behavior-driven development concepts. Christopher describes how BDD correlates with test-driven development and how it fosters collaboration within a team. We discuss building acceptance tests written in plain language and a handy tool for creating them.

We also share several other articles and projects from the Python community, including a news roundup, using regular expressions in Python, dealing with missing data in Polars, monkey patching in Django, first steps with Playwright, 3D printing giant things with a Python jigsaw generator, and a query language for JSON.

This episode is sponsored by Postman.

Topics:

• 00:00:00 – Introduction
• 00:02:21 – PyOhio 2025 July 26-27, 2025 Announced
• 00:02:38 – Python 3.13.2 and 3.12.9 now available!
• 00:02:52 – Django bugfix releases issued: 5.1.6, 5.0.12, and 4.2.19
• 00:03:04 – DjangoCon Europe 2025 - Real Python Podcast
• 00:05:24 – How to Deal With Missing Data in Polars
• 00:10:29 – Monkey Patching Django
• 00:15:50 – Sponsor: Postman
• 00:16:42 – My First Steps With Playwright
• 00:20:48 – How to Use Regular Expressions in Python
• 00:25:55 – Video Course Spotlight
• 00:27:25 – TDD vs. BDD: What’s the Difference?
• 00:50:13 – 3D Printing Giant Things With a Python Jigsaw Generator
• 00:53:58 – jmespath.py: Query Language for JSON
• 00:55:58 – Thanks and goodbye

News:

• PyOhio 2025 July 26-27, 2025 Announced
• Python 3.13.2 and 3.12.9 now available!
• Django bugfix releases issued: 5.1.6, 5.0.12, and 4.2.19
• DjangoCon Europe 2025: Schedule

Topics:

• How to Deal With Missing Data in Polars – In this tutorial, you’ll learn how to deal with missing data in Polars to ensure it doesn’t interfere with your data analysis. You’ll discover how to check for missing values, update them, and remove them.
• Monkey Patching Django – The nanodjango project is a modification to the Django framework that lets you get started with a single file instead of the usual cookie-cutter directory structure. This is a detailed post explaining how nanodjango monkey patches Django to achieve this result.
• Fake Django Objects With Factory Boy – The
• My First Steps With Playwright – Playwright is a browser-based automation tool that can be used for web scraping or testing. This intro article shows you how to use the Python interface to access a page including using cookies.
• How to Use Regular Expressions in Python – This post explores the basics of regular expressions in Python, as well as more advanced techniques. It includes real-world use cases and performance optimization strategies.

Discussion:

• TDD vs. BDD: What’s the Difference? – Discover the key differences between TDD vs BDD, their workflows, tools, and best practices for developers.
• Cucumber

Projects:

• 3D Printing Giant Things With a Python Jigsaw Generator – This is a long, detailed article on 3D printing objects too large for the printer bed. The author has created dovetail joints to assemble pieces together. He wrote a Python program to automatically split up the larger model files into the jigsaw pieces needed to build a final result.
• jmespath.py: Query Language for JSON

Additional Links:

• Polars — DataFrames for the new era
• nanodjango: Full Django in a single file - views, models, API ,with async support. Automatically convert it to a full project.
• factory_boy library is a tool for managing fixtures for your tests. This article shows you how to use it with Django.
• trimesh 4.6.2 documentation
• Email::RFC822::Address - Regex Recipe

Level up your Python skills with our expert-led courses:

• Regular Expressions and Building Regexes in Python
• Test-Driven Development With pytest
• How to Set Up a Django Project

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