In this chapter, we've covered the most important language syntax and standard library changes that have happened over the last four versions of Python. If you're not actively following Python release notes or haven't yet transitioned to Python 3.9, this should give you enough information to be up to date.
In this chapter, we've also introduced the concept of programming idioms. This is an idea that we will be referring to multiple times throughout the book. In the next chapter, we will take a closer look at many Python idioms by comparing selected features of Python to different programming languages. If you are a seasoned programmer who has just recently transitioned to Python, this will be a great opportunity to learn the "Python way of doing things." It will also be an opportunity to see where Python really shines, and where it might still be behind the competition.