class Role(object):

    def __init__(self,name,role,weapon,life_value): #初始化

        self.name = name

        self.role = role

        self.weapon = weapon

        self.life_value = life_value

    def buy_weapon(self,weapon):

        print("%s is buying [%s]" %(self.name,weapon))

        self.weapon = weapon

#role 的实例

#把一个抽象的类变成一个具体对象的过程叫实例化

p1 = Role('Alan','Police','B10',)

t1 = Role('Petter','Terrorist','B11',)

p1.buy_weapon("AK47") #Role.bur_weapon(p1,"AK47"）

t1.buy_weapon("B51")

print("P1:",p1.weapon)

print("T1:",t1.weapon）

class SchoolMember(object):

    def __init__(self,name,age,sex):

        self.name = name

        self.age = age

        self.sex = sex

    def enroll(self):

        print("SchoolMember%s is enrolled!" %self.name)

    def tell(self):

        print("My name is  %s" % self.name)

class Teacher(SchoolMember):

    def __init__(self,name,age,sex,course,salary):

        super(Teacher,self).__init__(name,age,sex)

        SchoolMember.__init__(self,name,age,sex)

        self.course = course

        self.salary =  salary

    def teaching(self):

        print("Teacher [%s] is teaching [%s]" %(self.name,self.course))

class Student(SchoolMember):

    def __init__(self,name,age,sex,course,tuition):

        super(Student,self).__init__(name,age,sex)

        self.course = course

        self.tuition = tuition

    def pay_tuition(self):

        print("Student [%s] paying tuition [%s]" %(self.name,self.tuition))

t1 = Teacher("John", 30, "Male", "C", 10000)

t2 = Teacher("Jonna", 25, "Female", "UI",15000)

s1 = Student("Jeff", 27, "Male", "PY", 10000)

s2 = Student("Alice", 28, "Male", "Java", 12000)

多态性（polymorphisn）是允许你将父对象设置成为和一个或更多的他的子对象相等的技术，赋值之后，父对象就可以根据当前赋值给它的子对象的特性以不同的方式运作。简单的说，就是一句话：允许将子类类型的指针赋值给父类类型的指针。

那么，多态的作用是什么呢？我们知道，封装可以隐藏实现细节，使得代码模块化；继承可以扩展已存在的代码模块（类）；它们的目的都是为了——代码重用。而多态则是为了实现另一个目的——接口重用！多态的作用，就是为了类在继承和派生的时候，保证使用“家谱”中任一类的实例的某一属性时的正确调用。

class Animal:

    def __init__(self, name):    # Constructor of the class

        self.name = name

    def talk(self):              # Abstract method, defined by convention only

        raise NotImplementedError("Subclass must implement abstract method")

class Cat(Animal):

    def talk(self):

        return 'Meow!'

class Dog(Animal):

    def talk(self):

        return 'Woof! Woof!'

def animal_talk(obj):

    print(obj.talk())

c = Cat("Cat")

d = Dog("Dog")

animal_talk(c)

animal_talk(d)

'''

animals = [Cat('Missy'),

           Dog('Lassie')]

for animal in animals:

    print (animal.name + ': ' + animal.talk())

'''