Some folks love the twin ideas that (1) "someone" might break the API rules and (2) they must write lots of bonus code to "prevent" problems.

Sigh.

There are three distinct things here.

• API definition - something we do all the time.
• "Defensive Programming" - something that may or may not actually …

Another case study on TDRE.

Provided: 2,938 lines of Python code which process a handful of large files to create a number of outputs. [Details can't be disclosed.]

Objective: Refactor to distinguish between the overall sequence of transformational steps and the details of each individual step.

Read this first: "There is something I find interesting about online discussions around performance issues..." It's about Stack Overflow, specifically. Apparently, someone didn't get their question answered and decided it was better to gripe than to rewrite the question.

Let's look at their response in pieces.

"people try to gang …

In "Unit Test Case, Subject Matter Experts and Requirements" I suggested that it's often pretty easy to get a spreadsheet of full-worked out examples from subject-matter experts. Indeed, if your following TDD, that spreadsheet of examples is solid gold.

Let's consider something relatively simple. Let's say we're working on some …

Here's a typical "I don't like TDD" question: the topic is "Does TDD really work for complex projects?"

Part of the question focused on the difficulty of preparing test cases that cover the requirements. In particular, there was some hand-wringing over conflicting and contradictory requirements.

Here's what's worked for me …

http://xkcd.com/730/

I almost wet myself. This is so typical.

I can't say enough good things about TDD.

But I'll try.

Due to an epic failure to read the documentation (this, specifically) I couldn't get our RESTful web services to work in Apache.

The entire application system has pretty good test coverage. I use the Python unittest to do integration …

Unit test coverage is a politically sensitive issue.

If you don't like (or want) unit testing, you set the threshold really high. 100% code coverage, or worse, 100% logic path coverage. Since these goals are difficult to achieve, the whole unit testing business can be made to go away.

If …

On Stack Overflow I was captivated by "What tools would you used to write a modular database in Python? " and "Implementing a 'rules engine' in Python ".

Both questions are quite amazing because they already have a modular, flexible rules engine (called "python") but it's not good enough: they want to …

Years ago, I was working with a client who was implementing their first web site.

Well, actually, it wasn't their first. It was their third. But their first two were haphazard "we hope this works" kind of web sites. They relied on third-party security and were pretty sure they were …