It is in Julia, but if you have it installed locally it’s just a few taps away. You can even generate the regex, and use that in Python and just add the ReadableRegex in a comment nearby.
That reads better than regex, but at that point, why not just use parser combinators? At least for me, whenever I want something more complex than a basic regex, I go for a parser combinator library. Maybe that's what's happening under the hood anyways? I don't know Julia well enough to know.
https://github.com/jkrumbiegel/ReadableRegex.jl
It is in Julia, but if you have it installed locally it’s just a few taps away. You can even generate the regex, and use that in Python and just add the ReadableRegex in a comment nearby.