Python 3 removes a lot of the confusion around Unicode handling in Python, but that by no means fixes everything. Different locales and writing systems have unique behaviours that can trip you up. Here's some of the worst ones and how to handle them correctly.
This talk was partly an excuse for me to geek out to an audience about writing systems, especially the Korean syllabary! You can watch a video of me speaking above, and see the slides from my talks below, with clickable links.