Looks like you're talking about URL escaping (or encoding).
Maybe take a look at using https://github.com/micropython/micropyt ... b/parse.py
It's relatively straightforward to do the transformation yourself %xx --> int(xx, 16).
But fom your example I can't tell if you're parsing a query string (i.e. it's made up of &-separated name=value pairs) or you just want to decode a single url-escaped value.