f-string renpy substitutor.py

import re

def formatter(s):
    def replacement(match):
        pre, bangs, suf = match.group(1, 2, 3)
        # pre : the part before the first bang
        # bangs : the bang (if any) and the characters going with it
        # suf : the colon (if any) and the characters going with it

        if not bangs:
            return eval("f\"{" + pre + suf + "}\"")

        conversion = set(bangs[1:]) # the first character is always a bang
        sra = conversion - set("tiqulc")
        conversion = conversion - sra
        if sra:
            sra = "!" + "".join(sra)

        value = eval("f\"{" + pre + (sra or "") + suf + "}\"")

        if "t" in conversion:
            value = renpy.translation.translate_string(value)

        if "i" in conversion:
            try:
                value = substitute(value, translate=False)[0]
            except RecursionError:
                raise ValueError("Substitution {!r} refers to itself in a loop.".format(value))

        if "q" in conversion:
            value = value.replace("{", "{{")

        if "u" in conversion:
            value = value.upper()

        if "l" in conversion:
            value = value.lower()

        if "c" in conversion and value:
            value = value[0].capitalize() + value[1:]

        return value

    return re.sub(r"\[([^!:\n]+)((?:![^!:\n]+)?)((?::[^!:\n]+)?)\]", replacement, s)