There are a lot of simple ideas that float about in programming. Many that are conceptually simple, yet end up being a bit tricky for you to implement. Right until the moment you see how somebody else does it, and you have a more concrete feeling for the simplicity.
Source: A Couple Lines To Improve Print-Based Debugging In Loops, an article by Raphael Gaschignard.
In this post, I will describe how to write unit tests for shell script components wich allow for mocking called commands.
Source: Writing Unit-Tests and Mocks for UNIX Shells, an article by Rainer Poisel.
I recently had a funny experience that turned out to be a great education in mutability of objects, especially strings, in Python. The experience came as a result of messing up on two Python brainteasers, getting annoyed about a seeming contradiction in the language functionality, and then going down a fascinating rabbit hole.
Source: Pointers, strings, and (im)mutability, an article by Danny D. Leybzon.