The online Python tutor visually walks through code and shows how it executes on the Python interpreter.
Python Module of the Week is a tour through the Python standard library.
A Python interpreter written in Python is incredibly meta but really useful for wrapping your head around some of the lower level stuff going on in the language.
A few things to remember while coding in Python is a nice collection of good practices to use while building programs with the language.
Python tricks that you can't live without is a slideshow by Audrey Roy that goes over code readability, linting, dependency isolation, and other good Python practices.
Python innards introduction explains how some of Python's internal execution happens.
What is a metaclass in Python is one of the best Stack Overflow answers about Python.
Armin Roacher presented things you didn't know about Python at PyCon South Africa in 2012.
Writing idiomatic Python is a guide for writing Pythonic code.
The thing that runs your Python is a summary of what one developer learned about PyPy while researching it.
There's an entire page on best Python resources with links but the following resources are a better fit for when you're past the very beginner topics.
The Python Ecosystem: An Introduction provides context for virtual machines, Python packaging, pip, virtualenv and many other topics after learning the basic Python syntax.
The Python Subreddit rolls up great Python links and has an active community ready to answer questions from beginners and advanced Python developers alike.
The blog Free Python Tips provides posts on Python topics as well as news for the Python ecosystem.
Python Books is a collection of freely available books on Python, Django, and data analysis.
Python IAQ: Infrequently Asked Questions is a list of quirky queries on rare Python features and why certain syntax was or was not built into the language.
A practical introduction to Functional Programming for Python coders is a good starter for developers looking to learn the functional programming paradigm side of the language.
Getting Started with the Python Internals takes a slice of the huge CPython codebase and deconstructs some of it to see what we can learn about how Python itself is built.