Mystery of Mutable Default Arguments in Python, How not to pass default arguments in Python and how to handle them properly? (more…)

Mark functions as async. Call them with await. All of a sudden, your program becomes asynchronous – it can do useful things while it waits for... (more…)

Pytest has a lot of features, but not many best-practice guides. Here’s a list of the 5 most impactful best-practices we’ve discovered at NerdWallet. At NerdWallet, we have a lot… (more…)

[Edit: A significantly expanded version of this series appears as a chapter in The Architecture of Open Source Applications, volume 4, as A Python … (more…)

Python provides some special function having __ as prefix and suffix in the name, which is also known as Magic method or Dunder method. This function is automatically invoked when the associated operator is used. For example, when + is used, the magic me... (more…)