I like the general thrust of PEP 498 (`f""` is explicit, unlike Ruby or Bash's magic `"` vs. `'`). That said, I think it would be much improved if it went the

I like the general thrust of PEP 498 (`f""` is explicit, unlike Ruby or Bash's magic `"` vs. `'`). That said, I think it would be much improved if it went the way of Scala and JavaScript (2015+) and made `r`, `u`, `b`, and `f` all interpolation providers. That way libraries could provide interpolators without having to extend the language to create a new one. For example, in Scala or JavaScript, you can create a string context / template tag for composing JSON strings, resulting in a nice syntax like this (scala-like): json"""{ "my": $data, "anArray": $someArray }""" The `data` and `someArray` values serialized to JSON by the `json` interpolation provider. At that point, internationalization is just creating your own interpolation provider and importing it as `i`, which is far less machinery than this PEP requires.