This post describes some good python resources that I found useful. Python has many resources, sometimes it becomes difficult for people to figure out which are good and which are not.
I am a big fan of Al Sweigart's book. He is very kind to provide the HTML version of the book online for free. I bought the hard copy and Udemy class, but the online version is very handy when I want to look something up quickly.
A presentation on youtube titled Recursion for Beginners: A Beginner's Guide to Recursion by Al Sweigart is also worth watching.
Google has a free class for people who want to learn Python. The class was created by Nick Parlante and was originally given to new Google employees. The contents of the class are quite good. It also comes with well-designed exercises for each lecture.
Think Python is a nice short introductory book by Allen B. Downey, and it only has 268 pages. Each chapter of the book has many nice exercises. The book is an easy read if you take programming courses before. The book is also freely available online. Here is the link.
Most introductory Python materials do not discuss python classes. Classes and Object Oriented Programming (OOP) concepts are everywhere for any serious Python work. I found the OOP chapter of a free online book A Byte of Python by Swaroop C H is a good introduction to the topic.
This Python Reference github page by Kevin Markham is a very nice summary of Python language features.
This online article by Trey Hunner examines all 69 python 3 built-in functions/callables. It is an excellent summary of python built-ins. Python 2 actually have a few more built-in callables.
I read the notes a few times and found that many examples apply to my existing python code. If I get a chance to revise those code, I will make sure they follow those recommendations.
I am currently reading Luciano Ramalho's Fluent Python book. I am half way through the book and it is good. The book covers many contents that I probably will never use, but it is always good to know more than we need.
I regularly listen to Talk Python To Me and Python Bytes podcasts. They keep me in the loop of a larger Python community.