This was a presentation for PyCon 2008 on how to understand Unicode in Python. It was mostly focused on Python 2 but the concepts still apply in Python 3, especially if you just want to understand dealing with byte code inputs.
View the slides: http://kumar303.github.io/unicode-in-python/
The source is in the public domain under the WTFPL license. It is free to re-use / re-write or anything you want.
To build the slides, create a virtualenv, edit unicode.txt, and run:
pip install -r requirements.txt python build.py