12.04公有，私有属性，析构函数，成员属性

class Role(object):
    nationality = "JPANA"   #公有属性
    def __init__(self,name,role,weapon,lift_value=100,money=15000):
        self.name = name
        self.role = role
        self.weapon = weapon    #成员属性
        self.lift_value = lift_value
        self.money = money
        self.__heart = "Normal"  #私有属性

    def shot(self):
        print("%s is shooting..."% self.name)

    def got_shot(self):
        print("oh....,I got shot....")
        self.__heart = "Die"
    def __del__(self):
        print("del.....run...")     #析构函数


r1 = Role("小王","警察","B22")
r2 = Role("小汪","警犬","B20")

def shot2(self):
    print("run my own shot method (out of class)",self.name)


print(r1.nationality)
print(r2.nationality)
Role.nationality = "US"
print(r1.nationality)
print(r2.nationality)
print("change r1 of nationality...")
r1.nationality = "China"
print(r1.nationality)
r1.shot()
r1.shot = shot2     #相当于将shot2代替r1.shot了
r1.shot(r1)
shot2(r1)        #在r1实例中，__init__的参数可以传到外部，所以说是公有属性。