Stateパターン

def main():
    obj = Context()
    obj.umbrella()
    obj.laundry()

    print("---")

    obj.change_state("rain")
    obj.umbrella()
    obj.laundry()


class State():
    def umbrella(self):
        raise NotImplementedError("umbrella is abstractmethod")

    def laundry(self):
        raise NotImplementedError("umbrella is abstractmethod")


class Sunnyday(State):
    def umbrella(self):
        print("bring no umbrella")

    def laundry(self):
        print("dry outdoor")


class Cloudyday(State):
    def umbrella(self):
        print("bring folding umbrella")

    def laundry(self):
        print("dry indoor")


class Rainyday(State):
    def umbrella(self):
        print("bring normal umbrella")

    def laundry(self):
        print("dry indoor")


class Context:
    def __init__(self):
        self.sunny = Sunnyday()
        self.rainy = Rainyday()
        self.cloudy = Cloudyday()
        self.state = self.sunny

    def change_state(self, weather):
        if weather == "sunny":
            self.state = self.sunny
        elif weather == "rain":
            self.state = self.rainy
        elif weather == "cloud":
            self.state = self.cloudy
        else:
            raise ValueError("change_state method must be in {}".format(["sunny", "rain", "cloud"]))

    def umbrella(self):
        self.state.umbrella()

    def laundry(self):
        self.state.laundry()


if __name__ == "__main__":
    main()

def umbrella(weather):
    if weather == "sunny":
        print("bring no umbrella")
    elif weather == "rain":
        print("bring folding umbrella")
    elif weather == "cloud":
        print("bring normal umbrella")


def laundry(weather):
    # こちらもif文を用いて書き換える必要がある