The authoritative guide and detailed guide to the Python programming language is intended for practicing programmers. The book is compact, aimed at the heart of the matter and written in very accessible language. Not only the core of the language is discussed in detail, but also the most important parts of the Python standard library. Additionally, a number of topics are covered that are not considered either in the official documentation or in any other sources. The reader is offered a practical acquaintance with the features of Python, including generators, coroutines, closures, metaclasses and decorators. New modules related to the development of multitasking programs using control threads and child processes, as well as designed for organizing network interactions and working with system services, are described in detail. In the completely revised and updated fourth edition, the organization of the material has been improved, which allows you to find answers to questions even faster and provides even greater convenience for working with the reference book. The book reflects the most significant innovations in the language and in the standard library that appeared in Python 2.6 and Python 3.