Python's Data Model Is an API. Here Is How to Use It Properly

Most Python developers know that __len__ makes len() work and __add__ makes + work. That is the surface. The actual story is that Python's data model is a coherent, documented protocol through which user-defined objects can participate in the language itself: not just operators, but truthiness, hashing, iteration, context management, attribute access, memory layout, and more. Using it well means understanding what CPython actually calls, in what order, and why. The Interpreter Calls These, Not Y