The scala people intend to use their version of this for things like xml literals:
snippet = xml"<h>hello world!</h1>"
Which are parsed and interned at compile time. Generally, it would be useful for embedding snippets of non-python code in strings within a python program, and have them resolved at import-time and interned to prevent run-time errors or performance overheads.
I'm thinking of regexes and libraries like
Parsimonious, which take literal strings to do stuff with, would benefit from this. No more "
should I or should I not re.compile() my regexes", no more worrying about whether the ad-hoc global compiled-regex cache is going to start evicting my regexes. For the vast majority of cases, regexes are static literals and can be compiled at import time without any fuss or global side effects (e.g. evicting others from the cache).