python inheritance init

that does not execute the constructor of the second parent class, and if the first parent class does not have a constructor, it goes to the second parent class to find - Pass 1 m1=man ('Alex', 33,10)2 w1=woman (' May ', +)34m1.make_friends (W1)5print (m1.friends[0].name) 6 Print (W1.friends[0].name)Both the man and the woman classes inherit the two parent classes of people and relation, but there are no constructors in the relation class. When woman is instantiated, it goes to the relation cl

, it is the beginning of the __ to hide a property.Supplemental Note: Encapsulation is definitely not a pure meaning of concealmentThe purpose of defining the attribute is to let the user use it, and the user wants to use the property hidden within the class.The designer of the class needs to open an interface within the class (define a method) to access the hidden properties inside the method, the user will then use this method to "indirectly" access internally hidden propertiesAs a designer of

Inheritance and derivation of classesClassic class and New classIn Python3, all classes inherit object by default, but all subclasses that inherit the object class, and subclasses of that subclass, are called modern classes (all classes in Python3 are modern classes)Subclasses that do not inherit the object class become the classic class (in Python2, a class that does not inherit object, and its subclasses, are classic classes)1 class People:2 PAS

inheritance and derivation of classesClassic class and New classIn Python3, all classes inherit object by default, but all subclasses that inherit the object class, and subclasses of that subclass, are called modern classes (all classes in Python3 are modern classes)Subclasses that do not inherit the object class become the classic class (in Python2, a class that does not inherit object, and its subclasses, are classic classes)1 class People:2 PAS

Classes and objectsThe essence of an object is a namespace, which holds its own unique properties, and the classes hold properties that are common to the object.__INIT__ will automatically trigger when the class is calledThere are two things that happen when you call a class:1. Create an empty object stu12. Automatically trigger the __INIT__ function, passing the STU1 and the parameters in parenthesesProperty LookupLook for the object's own namespace first, but not to the class.Binding methodA f

Benefits of Inheritance :1. Build the class in the system to avoid repetitive operation .2, the new class is often based on existing classes, so that you can improve the code reuse degree .Characteristics of inheritance :1, the construction of the base class in inheritance (The __init__ () method) is not automatically called, it needs to be called specifically in

): return self._birth @birth. Setter def birth (self, value): Self._birth = value @property def age return 2015-self._birth The above birth is a read-write property, which age is a readonly propertyII: Multiple Inheritance (MixIn)class Dog(Mammal, Runnable): passclass Bat(Mammal, Flyable): passWith multiple inheritance, a subclass can get all the functionality of multiple parent classes at the same tim

('%s bit%s'%(Self.name, person.name)) person.hp-=Self.aggrPrint(PERSON.HP) Alex= Person ('Alex','Felame', 1,250) Hei= Dog ('Little Black','Teddy', 260,10000) Alex.attack (HEI) hei.bite (Alex)#alex.eat ()Person.eat (Alex) animal.eat (Alex) Super (Person,alex) eat ()Three. Single InheritanceDo not occur with cyclic inheritanceDependency Inversion principle:High-rise modules should not rely on low-level modulesclassA:defWahaha (self):Print('In A')classB (A):defWahaha (self):Print('In B')classC (B):

Https://docs.python.org/2/tutorial/classes.html#multiple-inheritancehttp://www.jackyshen.com/2015/08/19/multi-inheritance-with-super-in-Python/http://python.jobbole.com/85685/In multiple inheritance, how to access a property in the parent class is determined in the order in __mro__ .About Super (), the prototype is this:super(type[, object-or-type]) Note:if The

Objective:Inheritance is one of the three main features of object-oriented, so you should pay attention to 3 points for inheritance.first, the basic searchIf the subclass inherits the parent class, the child class instantiates the object, and no methods and properties are found to the parent class.class # Parent Class def F1 (self): Print ('F1') class # sub-class Pass obj=sub () # If the subclass inherits the parent class, the child class instantiates the object, no methods an

point to look for. For example, the example should go back to the S2 class for the F2 () method,#the method is found in subclass S2 and is executed directly. If not in the S2 class, look for the F2 () method in the parent classSecond, multiple inheritance1. Simple Multiple inheritanceclassC0:defF1 (self):Print('c0_f1')classC1 (C0):defF2 (self):Print('C1_f2')classC2:defF2 (self):Print('C2_f2')classC3 (C2,C1):#inherit from left to right, high priority on left defF3 (self):Passobj=C3 () obj.f2

#!/usr/bin/env python#-*-Coding:utf-8-*-# Author:changhua Gongclass Person (object):def __init__ (self, name):Self.name = name # static propertyDef say (self): # method, dynamic propertyPrint ("Say ...")def speak (self):Print ("Speak ...")Class Relationship:def mk_friends (Self, somebody):Print ("%s is making friends with%s."% (Self.name, somebody.name))"Here somebody (Class) as a parameter, to ensure that a person renaming is still a new name, becaus

): - Pass - in #The top several are food, food does not need to have personality, so directly inherit all the fish class properties and methods can - #the shark class is defined below, this is the foodie, in addition to inherit the fish class properties and methods, but also to add a way to eat to + classShark (Fish): - def __init__(self): the Super (). __init__() *Self.hungry =True $ Panax Notoginseng defEat (self): - ifself.hungry: the Print("

initialization $Super ().__init__(name, age)#Superclass,super function directly inherits all, Super (man, self) ellipsisPanax NotoginsengSelf.sex =Sex -Self.friends = [] the + defWorking_hard (self): A Print("earning money.") the + defSleep (self):#Refactoring the methods of the parent class - people.sleep (self) $ Print("mans%s is sleeping"%self.name) $ - - classWoman (People, Relation): the - def __init__(Self,name, age, Sex ="woman"):WuyiSuper ().__init__(nam

Python, like C + +, supports multiple inheritance. Although the concept is easy, the hard work is that if a subclass invokes a property that itself does not have a definition, it is in what order to find it in the parent class, especially if many of the parent classes contain the same name attribute. For classic and modern classes, the order in which attributes are found is different. Now let's look at two

#继承#object base class, which is the parent class for all classes defined by Python#经典类: Classes that do not inherit object are called Classic classes#新式类: Classes that inherit object are called modern classes#python 3.x unified for new class#经典类是类对象, a new class is a type Object#经典类的继承是按照继承的顺序进行继承的#新式类是按照修改的优先级来继承, the higher the change priority is.Class Parent: #定义一个父类def __init__ (self):Self.age = 0def si