Python Class: Object-oriented advanced programming

First, class adds a new method:Methodtype

1. Plug-in class

   
   

Class Animal (object):
def __init__ (self, Name, age):
Self.name = Name
Self.age = Age
def run (self):
print ' Animal is run '

def set_color (self, color):
Self.color = color;
Print color

Dog = Animal (' pity ', 9)

Cat = Animal (' Miumiu ', 9)

From types Import Methodtype
Dog.set_color = Methodtype (Set_color, dog, Animal)

Dog.set_color (' Yellow ')

Print Dog.color

Cat.set_color (' White_yellow ')

Thus, methodtype specifies to be added in the dog object, not in the animal

2. Inline class

class Animal (object):
    def __init__ (self, Name, age):
         Self.name = name
        self.age = Age
    def run ( Self):
        print ' Animal is run '

def set_color (self, color):
Self.color = color;
Print color

dog = Animal (' pity ', 9)

Cat = Animal (' Miumiu ', 9)

From types Import Methodtype
Animal.set_color = Methodtype (Set_color, None, Animal)

Dog.set_color (' Yellow ')

Cat.set_color (' White_yellow ')

Format diagram:

Second,class restrictions Add new elements: __slots__

1. Normal class does not restrict the addition of elements

#!/usr/bin/env Python3
#-*-Coding:utf-8-*-

Class Animal (object):
def __init__ (self, Name, age):
Self.name = Name
Self.age = Age
def run (self):
print ' Animal is run '

Dog = Animal (' pity ', 9)

Dog.color = ' Yellow ' #dog实体添加了新元素color
Print Dog.color

2. Restrict adding new elements:__slots__

#!/usr/bin/env Python3
#-*-Coding:utf-8-*-

Class Animal (object):
__slots__ = (' name ', ' age ') #限制实体添加其他元素
def __init__ (self, Name, age):
Self.name = Name
Self.age = Age
def run (self):
print ' Animal is run '

Dog = Animal (' pity ', 9)
Print Dog.name

Dog.color = ' Yellow '

！！！ But!!!!!

For subclasses inheriting Animal , this method is not valid unless __slots__ is added to the subclass.

#!/usr/bin/env Python3
#-*-Coding:utf-8-*-

Class Animal (object):
__slots__ = (' name ', ' age ')
def __init__ (self, Name, age):
Self.name = Name
Self.age = Age
def run (self):
print ' Animal is run '

Class Cat (Animal): #添加继承Animal的子类
Pass

Cat = Cat (' Miumiu ', 9)
Cat.color = ' White_yellow '
Print Cat.color

Python Class: Object-oriented advanced programming