mixins、字类重用父类的方法super、多态、staticmethod、classmethod

mixins

# 多继承的正确打开方式：mixins机制
# mixins机制核心：就是在多继承背景下尽可能地提升多继承的可读性
# ps：让多继承满足人的思维习惯=》什么"是"什么
class Vehicle:
    pass

class FlyableMixin:
    def fly(self):
        pass

class CivilAircraft(FlyableMixin,Vehicle):  # 民航飞机
    pass

class Helicopter(FlyableMixin,Vehicle):  # 直升飞机
    pass

class Car(Vehicle):  # 汽车并不会飞，但按照上述继承关系，汽车也能飞了
    pass


import socketserver
# 补充：通常Mixin结果的类放在左边

字类重用父类的方法 super

# 在子类派生的新方法中如何重用父类的功能
# 方式一：指名道姓调用某一个类下的函数=》不依赖于继承关系
# class OldboyPeople:
#     def __init__(self,name,age,sex):
#         self.name=name
#         self.age=age
#         self.sex=sex
#
#     def f1(self):
#         print('%s say hello' %self.name)
#
# class Teacher(OldboyPeople):
#     def __init__(self,name,age,sex,level,salary):
#         OldboyPeople.__init__(self,name,age,sex)
#
#         self.level = level
#         self.salary=salary
#
# tea_obj=Teacher('egon',18,'male',10,3000)
# print(tea_obj.__dict__)

# 方式二：super()调用父类提供给自己的方法=》严格依赖继承关系
#        调用super()会得到一个特殊的对象，该对象会参照发起属性查找的那个类的mro,去当前类的父类中找属性
# class OldboyPeople:
#     def __init__(self,name,age,sex):
#         self.name=name
#         self.age=age
#         self.sex=sex
#
#     def f1(self):
#         print('%s say hello' %self.name)
#
# class Teacher(OldboyPeople):
#     def __init__(self,name,age,sex,level,salary):
#         # super(Teacher,self).__init__(name,age,sex)
#         super().__init__(name,age,sex) # 调用的是方法，自动传入对象
#
#         self.level = level
#         self.salary=salary
#
# # print(Teacher.mro())
# tea_obj=Teacher('egon',18,'male',10,3000)
# print(tea_obj.__dict__)

# super()案例
# class A:
#     def test(self):
#         print('from A')
#         super().test()
#
# class B:
#     def test(self):
#         print('from B')
#
# class C(A,B):
#     pass
#
# obj=C()
# obj.test()
#
# print(C.mro())

# class A:
#     def test(self):
#         print('from A')
#         super().test1()
#
# class B:
#     def test(self):
#         print('from B')
#
# class C(A,B):
#     def test1(self):
#         print('from C')
#
# obj=C()
# obj.test()
#
# print(C.mro())

多态

# 1、什么多态：同一事物有多种形态
# class Animal:
#     pass
#
# class People(Animal):
#     pass
#
# class Dog(Animal):
#     pass
#
# class Pig(Animal):
#     pass

# 2、为何要有多态=》多态会带来什么样的特性，多态性
#    多态性指的是可以在不考虑对象具体类型的情况下而直接使用对象
# class Animal: # 统一所有子类的方法
#     def say(self):
#         print('动物基本的发声频率。。。',end=' ')
#
# class People(Animal):
#     def say(self):
#         super().say()
#         print('嘤嘤嘤嘤嘤嘤嘤')
#
# class Dog(Animal):
#     def say(self):
#         super().say()
#         print('汪汪汪')
#
# class Pig(Animal):
#     def say(self):
#         super().say()
#         print('哼哼哼')
#
# obj1=People()
# obj2=Dog()
# obj3=Pig()

# obj1.say()
# obj2.say()
# obj3.say()

# 定义统一的接口，接收传入的动物对象
# def animal_say(animal):
#     animal.say()
#
# animal_say(obj1)
# animal_say(obj2)
# animal_say(obj3)

# print('hello'.__len__())
# print([1,2,3].__len__())
# print({'a':1,'b':2}.__len__())
#
# def my_len(val):
#     return val.__len__()

# print(my_len('hello'))
# print(my_len([1,2,3]))
# print(my_len({'a':1,'b':2}))

# len('hello')
# len([1,2,3])
# len({'a':1,'b':2})

# python推崇的是鸭子类型
# class Cpu:
#     def read(self):
#         print('cpu read')
#
#     def write(self):
#         print('cpu write')
#
# class Mem:
#     def read(self):
#         print('mem read')
#
#     def write(self):
#         print('mem write')
#
#
# class Txt:
#     def read(self):
#         print('txt read')
#
#     def write(self):
#         print('txt write')
#
# obj1=Cpu()
# obj2=Mem()
# obj3=Txt()
#
# obj1.read()
# obj1.write()
#
# obj2.read()
# obj2.write()
#
# obj3.read()
# obj3.write()

# 了解：
# import abc
#
# class Animal(metaclass=abc.ABCMeta): # 统一所有子类的标准
#     @abc.abstractmethod
#     def say(self):
#         pass
#
# # obj=Animal() # 不能实例化抽象类自己
#
# class People(Animal):
#     def say(self):
#         pass
#
# class Dog(Animal):
#     def say(self):
#         pass
#
# class Pig(Animal):
#     def say(self):
#         pass

# obj1=People()
# obj2=Dog()
# obj3=Pig()

staticmethod、classmethod

# 一：绑定方法：特殊之处在于将调用者本身当做第一个参数自动传入
#    1、绑定给对象的方法：调用者是对象，自动传入的是对象
#    2、绑定给类的方法：调用者类，自动传入的是类
# import settings
#
# class Mysql:
#     def __init__(self,ip,port):
#         self.ip=ip
#         self.port=port
#
#     def func(self):
#         print('%s:%s' %(self.ip,self.port))
#
#     @classmethod # 将下面的函数装饰成绑定给类的方法
#     def from_conf(cls):
#         print(cls)
#         return cls(settings.IP, settings.PORT)
#
# # obj1=Mysql('1.1.1.1',3306)
#
# obj2=Mysql.from_conf()
# print(obj2.__dict__)

# 二：非绑定方法-》静态方法：
#    没有绑定给任何人：调用者可以是类、对象，没有自动传参的效果

# class Mysql:
#     def __init__(self,ip,port):
#         self.nid=self.create_id()
#         self.ip=ip
#         self.port=port
#
#     @staticmethod # 将下述函数装饰成一个静态方法
#     def create_id():
#         import uuid
#         return uuid.uuid4()
#
#     @classmethod
#     def f1(cls):
#         pass
#
#     def f2(self):
#         pass
# obj1=Mysql('1.1.1.1',3306)

# print(Mysql.create_id)
# print(obj1.create_id)

# Mysql.create_id(1,2,3)
# obj1.create_id(4,5,6)

# print(Mysql.create_id)
# print(Mysql.f1)
# print(obj1.f2)