prog11_11.py

class Cat:
    VOICE = "ニャー"

    def __init__(self, name):
        self.name = name

    def talk(self, loud=False):
        if loud:
            times = 3
        else:
            times = 1
        voice = self.__class__.VOICE
        print(f"{self.name}「{voice*times}」")

print("猫の鳴き声は", Cat.VOICE)
c1 = Cat("みけ")
c2 = Cat("とら")
c1.talk()
c2.talk(loud=True)

# プログラム11-11（クラス変数）