Software development processes create value, and have waste, in the Lean sense of the word waste.

I'm going to use the term waste and value in future episodes. I'm using waste in a Lean sense, so we can look at software processes critically, see the value chain, and try to reduce waste.

Lean manufacturing and lean software development caused people to talk about and examine waste and value, even in fields where we didn't really think about waste that much to begin with.

Software is just ones and zeros. Is there waste?

The mistake I'm making here is confusing the common English definition of waste when what we're talking about is the Lean definition of waste.

This episode tries to clear up the confusion.

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Links:

• Big Design Up Front
• Lightweight Methodologies
• Manifesto for Agile Software Development
• Extreme programming
• The New Methodology
• Test First Programming / Test First Development
• Test Driven Development
• The Pragmatic Programmer
• Six Sigma
• DMAIC
• Lean software development
• Lean manufacturing
• The Toyota Way
• Lean Six Sigma
• Definition of Waste by Merriam-Webster

Should your code be DRY or DAMP or something completely different?

We'll get to all of these definitions, and then talk about how it applies to both production code and test code in this episode.

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Sponsored By:

• Datadog: Modern end-to-end monitoring & security. See inside any stack, any app, at any scale, anywhere. Get started with a free trial at testandcode.com/datadog and Datadog will send you a free t-shirt.

Links:

• The Pragmatic Programmer, 20th Anniversary Edition
• Don't repeat yourself - Wikipedia
• a-ha - Take On Me
• Rule of three - Wikipedia
• What does “DAMP not DRY” mean when talking about unit tests? - Stack Overflow

When learning data science and machine learning techniques, you need to work on a data set.

In this episode we talk about:

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Special Guest: Matt Harrison.

Sponsored By:

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

Links:

• Applied Pandas: Twitter Analytics — the course
• matt harrison (@__mharrison__) / Twitter — follow for Python, Data Science, & Career Advice
• Brian Okken (@brianokken) / Twitter — follow for Python, pytest, Packaging, & Software Engineering Advice

Iterative processes that include writing test code and production code together, such as TDD, help make coding fun.

All of us that care about developing quality code with the help of testing can learn from each other, regardless of programming language.

Today we step outside our normal Python comfort zone and talk with Gio about TDD in Swift.

Gio Lodi, author of TDD in Swift, joins the show to discuss Test Driven Development, software workflows, bottom up vs top down, rapid feedback, developer vs customer facing tests, and more.

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Special Guest: Gio Lodi.

Sponsored By:

• Datadog: Modern end-to-end monitoring & security. See inside any stack, any app, at any scale, anywhere. Get started with a free trial at testandcode.com/datadog and Datadog will send you a free t-shirt.

Links:

• TDD in Swift with SwiftUI and Combine
• mokacoding - Gio's blog
• XCTest
• Software Design: Tidy First? - Kent Beck on Substack

pre-commit started as a framework for running linters and code formatters during git actions via git hooks. It's grown and expanded and now supports an extensive list of languages and actions and manual running of actions. But even at it's core, it's great for letting computers nitpick about whitespace and formatting, so that code reviews can focus on architecture and design.

Anthony Sottile discusses pre-commit, for using locally by developers, and pre-commit.ci, which can run actions during merge requests.

"Git hook scripts are useful for identifying simple issues before submission to code review. We run our hooks on every commit to automatically point out issues in code such as missing semicolons, trailing whitespace, and debug statements. By pointing these issues out before code review, this allows a code reviewer to focus on the architecture of a change while not wasting time with trivial style nitpicks." - pre-commit.com

"Developers spend a fair chunk of time during their development flow fixing relatively trivial problems in their code. pre-commit.ci both enforces that these issues are discovered, which is opt in for each developer workflow via pre-commit, but also fixes the issues automatically, letting developers focus their time on more valuable problems." - A user of pre-commit.ci

Full Transcript

Special Guest: Anthony Sottile.

Sponsored By:

• PyCharm Professional: Try PyCharm Pro for 4 months and learn how PyCharm will save you time. Promo Code: TESTANDCODE22
• ConfigCat.com: Release features faster with less risk with ConfigCat. You can try it out with the forever free plan or get 25% off with code testandcode2021 Promo Code: testandcode2021

Links:

• pre-commit
• pre-commit supported hooks
• pre-commit.ci

Flake8 is a command-line tool for linting Python projects.

But what does all of that mean?

Anthony Sottile is a maintainer of flake8 and has kindly offered to explain it to us.

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Special Guest: Anthony Sottile.

Sponsored By:

• Datadog: Modern end-to-end monitoring & security. See inside any stack, any app, at any scale, anywhere. Get started with a free trial at testandcode.com/datadog and Datadog will send you a free t-shirt.

Links:

• Flake8: Your Tool For Style Guide Enforcement
• pyflakes
• pycodestyle
• mccabe
• pyflakes/messages.py
• flake8 Error / Violation Codes
• wemake-python-styleguide
• flake8-typing-imports
• tox automation project
• Nox
• pre-commit

Tim Ottinger has four questions that work great in many situations, from doing homework, to cooking, to writing code, to entire software projects.

They are actually awesome questions to ask during a software project.

We discuss the questions, where they came from, and look at some uses in software.

The questions:

Bonus question that can be swapped out for #1:

Full Transcript

Special Guest: Tim Ottinger.

Sponsored By:

• PyCharm Professional: Try PyCharm Pro for 4 months and learn how PyCharm will save you time. Promo Code: TESTANDCODE22
• ConfigCat.com: Release features faster with less risk with ConfigCat. You can try it out with the forever free plan or get 25% off with code testandcode2021 Promo Code: testandcode2021

Links:

• The Four Questions

You need tests for your web app. And it has a database. What do you do with the database during testing? Should you use the real thing? or mock it? Jeff Triplett says don't mock it.

In this episode, we talk with Jeff about testing web applications, specifically Django apps, and of course talk about the downsides of database mocking.

Full Transcript

Special Guest: Jeff Triplett.

Sponsored By:

• Datadog: Modern end-to-end monitoring & security. See inside any stack, any app, at any scale, anywhere. Get started with a free trial at testandcode.com/datadog and Datadog will send you a free t-shirt.

Links:

• "🤔 In ~12 years, I have never seen a case where mocking a database was a good idea. ..."

Playwright is an end to end automated testing framework for web apps with Python support and even a pytest plugin.

Full Transcript

Special Guest: Ryan Howard.

Sponsored By:

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

Links:

• Playwright for Python
• Why Playwright?
• playwright-pytest

I always learn a lot when I talk to Brett, and this episode is no exception.

Full Transcript

Special Guest: Brett Cannon.

Sponsored By:

• Datadog: Modern end-to-end monitoring & security. See inside any stack, any app, at any scale, anywhere. Get started with a free trial at testandcode.com/datadog and Datadog will send you a free t-shirt.

Links:

• pytest-srcpaths
• Python Packaging User Guide
• pypa/packaging: Core utilities for Python packages
• flit and requires-python
• Extending and Embedding the Python Interpreter — Python 3.9.2 documentation
• Flit
• setuptools
• PEP 518 -- Specifying Minimum Build System Requirements for Python Projects | Python.org
• PEP 517 -- A build-system independent format for source trees | Python.org
• Flit editable installs with --symlink or --pth-file
• PEP 440 -- Version Identification and Dependency Specification | Python.org
• Specifying requires-python with flit
• wheel
• Universal 1 binary
• Universal 2 binary
• Cython: C-Extensions for Python
• CFFI
• pybind11: Seamless operability between C++11 and Python
• Conda
• conda environments
• conda-forge
• VaultsOfParnassus