Python 3 Study Notes (Volume 1)

Python 3 Study Notes (Volume 1) is the language volume of Yuhen's two-volume Python 3 Study Notes. Taking the syntax and runtime of Python 3.6 as its baseline, it begins with how the interpreter works and explains the design background and implementation behind the language. The content stays focused on the language itself: it first outlines CPython's compilation and execution flow and the relationship between names and memory, then works through the underlying behavior of built-in types, the semantics of expressions and assignment, functions and scope, closures and calls, iterators and generators, module and package import mechanisms, and classes, inheritance, multiple inheritance, operator overloading, exceptions, and context management. Beyond basic syntax, the book discusses metaprogramming mechanisms such as decorators, descriptors, and metaclasses in depth, and analyzes interpreter internals including bytecode, the global interpreter lock (GIL), memory allocation, and garbage collection; it also briefly introduces extension approaches such as ctypes and Cython, along with testing and profiling tools including unittest, coverage, timeit, and profile. The author's aim is not to list grammar rules but to help readers see the complex system that is encapsulated and hidden beneath the surface of "simple and easy to use." Compact and principle-oriented throughout, the book suits readers who can already write Python programs and want a deeper understanding of language semantics and interpreter behavior, whether for study or reference.