Dan B4,860 Points
Remember that "collections" are being retired in Python 3.9 so all the old 2016 material is going to be retired also.
Another user asked this question before so I figured I'd put it here (sorry for the confusion as this thread isn't actually a question itself either).
Official Python Documentation: https://docs.python.org/3/library/collections.html
Deprecated since version 3.3, will be removed in version 3.9: Moved Collections Abstract Base Classes to the collections.abc module. For backwards compatibility, they continue to be visible in this module through Python 3.8.
We're currently on Python 3.8 and 3.9 will be released next year sometime in 2020.
So what should you do next then instead of following on what Craig said about learning collections next?
The answer: Tuples! Just continue on with the path if you want to keep learning about Python.