Now, any valid Python expression is accepted as a solution. There are more than 100 exercises covering both the builtin `re` module and the third-party `regex` module.
These exercises have been adapted from my Understanding Python re(gex)? ebook [1] (free to read online, and PDF/EPUB versions are free till the end of this month).
See [2] for a video demo. I'd appreciate your feedback, happy learning :)
[0] https://news.ycombinator.com/item?id=29391107
[1] https://github.com/learnbyexample/py_regular_expressions