What you need for this book
All you need to follow through the examples in this book is a computer running any Python 3.8.5 or newer. Some of the examples can be adapted to work with Python 3 versions prior to 3.8. A number of examples are specific to Python 3.8 features.
It's often easiest to install a fresh copy of Python. This can be downloaded from https://www.python.org/downloads/. An alternative is to start with
Miniconda (https://docs.conda.io/en/latest/miniconda.html) and use the
conda tool to create a Python 3.8 (or newer) environment.
Python 2 cannot easily be used any more. Some Linux distributions and older macOS releases included a version of Python 2. It should be thought of as part of the operating system, and not a general software development tool.