Python is used in a wide range of domains owing to its simple yet powerful nature. Although writing Python code is easy, making it readable, reusable, and easy to maintain can be challenging. Complete with best practices, useful tools, and standards implemented by professional Python developers, this fourth edition will help you in not only overcoming such challenges but also learning Python's latest features and advanced concepts. The book begins with a warm-up, where you will catch-up with the latest Python improvements, syntax elements, and interesting tools to boost your development efficiency. Further, the initial few chapters should allow experienced programmers coming from different languages to safely land in the Python ecosystem. As you progress, you will explore common software design patterns and various programming methodologies, such as event-driven programming, concurrency, and metaprogramming. You will also go through complex code examples and try to solve meaningful problems by bridging Python with C and C++, writing extensions that benefit from the strengths of multiple languages. Finally, you will understand the complete lifetime of any application after it goes live. By the end of the book, you should be proficient in writing efficient and maintainable Python code. The Python programming book is intended for expert programmers who want to learn Python's advanced-level concepts and latest features. Anyone who has basic Python skills should be able to follow the content of the book, although it might require some additional effort from less experienced programmers. It should also be a good introduction to Python 3.9 for those who are still a bit behind and continue to use other older versions.