How to Implement the Flyweight Pattern in Python

class Character:
    """Flyweight - stores only intrinsic state (shared)."""

    def __init__(self, char: str, font: str):
        self.char = char
        self.font = font

    def render(self, size: int) -> str:
        return f"{self.char}_{self.font}_{size}"


class CharacterFactory:
    """Flyweight factory - manages shared instances."""

    def __init__(self):
        self._styles = {}

    def get_character(self, char: str, font: str) -> Character:
        key = (char, font)
        if key not in self._styles:
            self._styles[key] = Character(char, font)
        return self._styles[key]

    def count(self) -> int:
        return len(self._styles)


def main():
    factory = CharacterFactory()

    document = [
        factory.get_character("H", "Arial"),
        factory.get_character("e", "Arial"),
        factory.get_character("l", "Arial"),
        factory.get_character("l", "Arial"),
        factory.get_character("o", "Arial"),
        factory.get_character("W", "Times"),
        factory.get_character("o", "Times"),
        factory.get_character("r", "Times"),
        factory.get_character("l", "Times"),
        factory.get_character("d", "Times"),
    ]

    for ch in document:
        print(ch.render(12))

    print(f"\nUnique flyweights created: {factory.count()}")


if __name__ == "__main__":
    main()