Comment by j4mie

I wrote a library a little while ago which is intended to be the simplest possible expression of this idea:

https://github.com/j4mie/hotmetal/

The core implementation is only 85 lines of Python, and has no imports at all, so works nicely on minimal/alternative Pythons like Micropython.

I'm using it on a medium-sized side project and it's shockingly productive compared to string templates. I don't think anyone is using it except me, though.