pythonでの単一設計モード(一度の初期化方法のみを実行)

class animal(object):
    #             
    flag = False

    #      
    def __init__(self):
        if animal.flag:
            return
        print("       ")
        animal.flag = True


a1 = animal()
print(a1)
a2 = animal()
print(a2)
a3 = animal()
print(a3)


# ——————    ——————
#        
# <__main__.animal object="" at=""/>
# <__main__.animal object="" at=""/>
# <__main__.animal object="" at=""/>