This is another Regex engine, this time written in Python.
I wrote this version of the regex engine before I wrote the one I wrote in C. Similarly to how I wrote the C engine to give myself a stress test of my skills in C, I also wrote this engine as a way to test my skills in Python shortly after I learned the language.
(You may also notice that this file is 1000 lines long to implement an entire regex engine in Python, but the C version is split into many files with multiple of those being larger than 1000 lines. If there is any testament to how powerful Python is as a scripting language, it should be this.)