#!/usr/bin/python3
import re


class Rule:

    def __init__(self, *path, **properties):
        self.path = path
        self.properties = properties

    def _f(self, prop):
        key, value = prop
        key = re.sub("([A-Z])", "-\\1", key).lower()
        return "  {}: {};".format(key, value)

    def __format__(self):
        result = " ".join(self.path)
        result += " {\n"
        result += "\n".join(map(self._f, self.properties.items()))
        result += "\n}\n"
        return result


def string(*rules):
    return "\n".join(map(lambda r: r.__format__(), rules))

if __name__ == "__main__":
    print("CSS Demo")
    print(Rule(".foo", "#blah", backgroundColor="red").__format__())