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)
练习:创建一个对象,每实例化一个对象就计数。 最终所有对象都共享这个数据
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
人狗大战升级版
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())
栗子1:运用组合计算圆环的面积和周长
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)
栗子2:用组合创建一个老师类,有生日且生日是一个类
原文地址:https://www.cnblogs.com/twinkle-/p/10551431.html
时间: 2024-10-03 05:39:27