Fluent Python

Fluent Python explains why Python’s idioms work the way they do — the data model behind operator overloading, how iterators and generators actually work, what makes an object “Pythonic” — rather than just listing syntax. It’s not a beginner book in the day-one sense; read it once basic syntax is comfortable, as the point where it closes a real gap.

The reference most often recommended alongside ArjanCodes for developers moving from “knows Python” to “writes Python that looks like Python.”