Internals of Python 3.x transform a programmer's learning path by emphasizing the source code over the syntax to teach things from the ground up in nearly the same amount of time and effort. The book delves into the structure and distinctions between the primary Python object and iterable objects. The iterable types, namely, lists and tuples, have been thoroughly defined in the structure and operations. The internals of sets and dictionaries, which are data structures that provide O(1) insertion and search, have been thoroughly discussed. Memory allocation explains how Python handles memory for tiny and large objects. The chapter on GIL explains how the GIL works, which is halted by a semaphore and a conditional variable. The chapter on Async Python describes how the async module generates coroutines and async functions that can be executed on an event loop and interact through events. After reading this book, you will be more confident to create high-performance code on a day-to-day basis.