类_练习题

练习1：编写一个学生类，产生一堆学生对象

class Student:
    school = 'Luffycity'
    count = 0

    def __init__(self, name, age, sex):
        self.name = name
        self.age = age
        self.sex = sex
        self.count += 1

    def learn(self):
        print('%s is learning' % self.name)

stu1 = Student('alex', 'male', 38)
stu2 = Student('jinxin', 'female', 78)
stu3 = Student('Egon', 'male', 18)

print(Student.count)
print(stu1.count)
print(stu2.count)
print(stu3.count)

结果输出

0
1
1
1

从以上结果可以看出，如果写成self.count ,他就会变成对象的私有属性，所以说虽然实例化了3次，但是类的count值为0，每个对象的count值为1

以下代码验证

print(stu1.__dict__)
print(stu2.__dict__)
print(stu3.__dict__)

结果为

{'name': 'alex', 'age': 'male', 'sex': 38, 'count': 1}
{'name': 'jinxin', 'age': 'female', 'sex': 78, 'count': 1}
{'name': 'Egon', 'age': 'male', 'sex': 18, 'count': 1}

修改代码

class Student:
    school = 'Luffycity'
    count = 0

    def __init__(self, name, age, sex):
        self.name = name
        self.age = age
        self.sex = sex
        # self.count += 1
        Student.count += 1

    def learn(self):
        print('%s is learning' % self.name)

stu1 = Student('alex', 'male', 38)
stu2 = Student('jinxin', 'female', 78)
stu3 = Student('Egon', 'male', 18)

print(Student.count)
print(stu1.count)
print(stu2.count)
print(stu3.count)
print(stu1.__dict__)
print(stu2.__dict__)
print(stu3.__dict__)

结果为：

3
3
3
3
{'name': 'alex', 'age': 'male', 'sex': 38}
{'name': 'jinxin', 'age': 'female', 'sex': 78}
{'name': 'Egon', 'age': 'male', 'sex': 18}

练习2：模仿王者荣耀定义两个英雄类

要求：

1. 英雄需要有昵称、攻击力、生命值等属性；
2. 实例化出两个英雄对象；
3. 英雄之间可以互殴，被殴打的一方掉血，血量小于0则判定为死亡。

class Hero:
    def __init__(self,nick_name, life_value, aggresivity):
        self.nick_name = nick_name
        self.life_value = life_value
        self.aggresivity = aggresivity

    def attack(self, enemy):
        enemy.life_value -= self.aggresivity


# r1 = Hero('可爱的锐雯雯', 80, 50)
# g1 = Hero('草丛伦', 100, 30)
# print(r1.life_value)
# g1.attack(r1)
# print(r1.life_value)


class Riven(Hero):
    camp = 'Noxus'

    # def __init__(self, nick_name, life_value, aggresivity):
    #     super(Riven, self).__init__(nick_name, life_value, aggresivity)


class Garen(Hero):
    camp = 'Demacia'

    # def __init__(self, nick_name, life_value, aggresivity):
    #     super(Garen, self).__init__(nick_name, life_value, aggresivity)


r1 = Riven('可爱的锐雯雯', 80, 50)
g1 = Garen('草丛伦', 100, 30)
print(r1.life_value)
g1.attack(r1)
print(r1.life_value)
print(r1.camp)
print(g1.camp)

# 通过继承的方式新建类B，让B继承A，B会‘遗传’A的所有属性(数据属性和函数属性)，实现代码重用