类的命名空间&组合

类的命名空间
◆类中的静态变量可以被类调用也可以被对象调用
◆对不可变数据类型来说，类变量最好用类名操作

class Person:
    money = 0
mother = Person()
father = Person()
Person.money += 1000
Person.money += 1000
print(Person.money)

 ◆对于可变数据类型来说，对象的修改是共享的，重新赋值是独立的

class Course:
    langauage = 'Chinese'
    def __init__(self,name,period,price,teacher):
        self.name =name
        self.period =period
        self.price =price
        self.teacher =teacher
    def func(self):
        pass
python = Course('python','six months',2000,'Wang')
print(python.__dict__)
print(python.langauage)
Course.langauage = 'English'
print(Course.langauage)# English
print(python.langauage)# English
python.langauage = '阿拉伯'
print(python.langauage)# 阿拉伯   没有修改类中的值而是在python这个对象的命名空间中增加了一项'langauage': '阿拉伯'
print(Course.langauage)# English
print(python.__dict__) # {'name': 'python', 'price': 2000, 'period': 'six months', 'langauage': '阿拉伯', 'teacher': 'Wang'}

class Foo:
    count = 0
    def __init__(self):
        Foo.count += 1
f1 = Foo()
f2 = Foo()
print(f1.count)
print(f2.count)
f3 = Foo()
print(f3.count)

绑定方法：
◆只有对象调用类内的方法的时候才有绑定方法的概念，
◆当对象调用类内的方法的时候就是把对象中的值传给这个方法的self，所以这个对象和这个方法就有了绑定关系

#普通函数
def func():pass
print(func)  #<function func at 0x0000023DFAD0E488>
# 类
class Foo:
    def func(self):
        print('func')
f1 = Foo()
print(Foo.func) # <function Foo.func at 0x0000023DFAD0E950>
print(f1.func) #对象调用方法 ，把f1的值传给self  f1和func发生了绑定
# <bound method Foo.func of <__main__.Foo object at 0x000001F5784E8780>>
print(f1) # <__main__.Foo object at 0x000001F5784E8780>


补充：导入包的过程，就相当于实例化一个对象，就会自动执行__init__.py文件

 

面向对象的三大特性 ： 继承   多态   封装

组合 : 一个类的对象是另一个类对象的属性

如：alex.weapon 是 Weapon 类的对象  （alex.weapon 相当于 w）

# 狗
class Dog:
    def __init__(self,name,aggr,blood,kind):
        self.name = name
        self.aggr = aggr
        self.blood = blood
        self.kind = kind
    def bites(self,person):
        person.blood -= self.aggr
# 人
class Person:
    def __init__(self,name,aggr,blood,sex):
        self.name = name
        self.aggr = aggr
        self.blood = blood
        self.sex = sex
        self.money = 0
    def attack(self,dog):
        dog.blood -= self.aggr

    def get_weapon(self,weapon):
        # 首先判断玩家的money够不够买装备
        if self.money >= weapon.price:
            # 玩家买完武器之后money减少
            self.money -= weapon.price
            # 玩家有了武器
            self.weapon = weapon
            # 玩家的攻击力增加
            self.aggr += weapon.aggr
        else:
            print('余额不足，请先充值')
# 武器装备
class Weapon:
    def __init__(self,name,price,aggr,naijiudu):
        self.name = name
        self.price = price
        self.aggr = aggr
        self.naijiudu = naijiudu
    # 大招
    def hand18(self,person):
        if self.naijiudu > 0 : # 如果还有耐久度
            person.blood -= self.aggr * 2 # 被攻击的人的血就掉攻击者攻击力的两倍
            self.naijiudu -= 1  # 耐久度减一

alex = Person('alex',0.5,100,'女')
jin = Dog('金老板',100,500,'泰迪')
w = Weapon('打狗棒',998,100,3)
# alex 装备打狗棒
alex.money += 1000
alex.get_weapon(w)
print(alex.aggr) # 100.5
print(alex.weapon) # <__main__.Weapon object at 0x000001C8C55886A0>
# alex 攻击 金老板
alex.attack(jin)
print(jin.blood)  # 399.5
# alex使用大招攻击金老板
alex.weapon.hand18(jin)
print(jin.blood)  # 199.5

from math import pi
class Cricle:
    def __init__(self,r):
        self.r = r
    def area(self):
        return pi * self.r ** 2
    def perimeter(self):
        return 2 * pi * self.r

class Ring:
    def __init__(self,outside_r,inside_r):
        self.outside_c = Cricle(outside_r) # Cricle(outside_r)是Cricle的对象，但是在这里是Ring类的属性
        self.inside_c = Cricle(inside_r)
    def area(self):
        return self.outside_c.area() - self.inside_c.area()
    def perimeter(self):
        return self.outside_c.perimeter() + self.inside_c.perimeter()
ring = Ring(20,10)
print(ring.area())
print(ring.perimeter())

class Teacher:
    def __init__(self,name,age,sex,brithday):
        self.name = name
        self.age = age
        self.sex = sex
        self.brithday = brithday
        self.course = Course('alex',2000,'six months')
class Course:
    def __init__(self,name,price,month):
        self.name = name
        self.price = price
        self.month = month


class Birthday:
    def __init__(self,year,month,day):
        self.year = year
        self.month = month
        self.day = day

b = Birthday(2018,7,25)
alex = Teacher('alex',1,'女',b)
print(alex.name)
print(alex.brithday.year)
print(alex.brithday.month)
print(alex.brithday.day)
print(alex.course.price)