Optional Values

Sometimes we work with variables that may or may not have an "actual value." For example, a character might have a damage bonus, or they might not. If they don't, we can represent that lack of value with None.

The | operator indicates that a value can be of multiple types:

damage_bonus: int | None

That means damage_bonus can be either an integer (the bonus amount) or None. For another example, a function might return a prepared spell if one is ready, or None if no spell is prepared:

def get_prepared_spell(has_spell: bool) -> str | None:
    if has_spell:
        return "Fireball"

    return None