Python full stack development "13th" Python Object-oriented

first, the process : process-oriented program design is the core process (pipeline thinking), the process is to solve the problem, process-oriented design is like a well-designed pipeline, consider when to deal with what things.

Pros: Dramatically reduce the complexity of writing, just follow the steps, stack the code to

Disadvantage: A set of pipelines or processes is used to solve a problem, if the code changes will have to change

Ii. Object-oriented : the Thought of God

Advantages: It solves the extensibility of the program. A single modification of an object is immediately reflected in the entire system, such as the character of a character parameter in the game and the ability to modify it easily.

Cons: Poor controllability, inability to process-oriented programming pipelining can accurately predict the problem of the processing process and results, the object-oriented program once started by the interaction between the object to solve the problem, even God can not predict the end result. So we often see a game of people changes in a certain parameter is likely to lead to the ability of the bully to appear, a knife to kill 3 people, the game is out of balance.

class : A kind of thing with the same characteristics (man, dog, Tiger)

Object/instance: a specific thing

Instantiation: Class-to-object procedure (instance = class name (parameter 1, parameter 2))

Iv. Initial classes and objects

Classes: Class Person: #class class Name: Notice that the class name is followed by no parentheses

Class Body

In Python, a class of things that have the same characteristics and skills are ' classes ', using variables to represent features, to represent skills with functions,

Objects are specific to this kind of thing

Two functions of a class: Property Reference and instantiation

#属性引用class Person:    role = ' Chinese '  #类属性----static property    def walk (self):  #这里的函数叫做方法-----Dynamic Property        #注意: Self must write Print        (' person is walking ... ') print (person.role) #查看类属性print (person.walk) #查看类方法, call the method name with the class name and print out the memory address

#实例化class Person:    role = ' Chinese '    def __init__ (self,name,sex):        self.name=name        self.sex=sex    def Walk (self):        print (' walking ') hy = person (' Haiyan ', +) #实例化: The class name (parameter 1, parameter 2)  class name () is equal to the execution of the person.__init__ () print (hy.name)  #直接查看属性   object name. Property name Print (hy) #返回的是一个对象hy. Walk ()  #调用方法  , Object name. Method ()

Two functions of objects: viewing properties and calling methods (as described in the instantiation above)

V. About SELF

Self: The object/instance itself is automatically passed to the first parameter of __init__ when instantiated, and you can give it an individual name, but normal people don't do it because you don't know anyone else.

NOTE: def __init__ (self): This sentence can be written or not written, as long as there are parameters to enter the time must be written

def method Name (self): the self here must be written

VI. Special class Attributes

Print (Person.__name__,type (person.__name__)) #查看类的名字 (where the class name is a string type) print (person.__dict__) #查出的是一个字典, key is the property name, Value is the property values print (person.__doc__) # is to display the comments out of print (dir (person)) #查看类的方法, displayed as a list of print (person.__module__) # Module print (person.__class__) print (Isinstance (Hy,person)) where the class definition resides #判断对象 is an instance of the class

　　

Vii. related knowledge of objects

1. The object is an example of a class that actually exists, i.e. the instance

2. Object/instance has only one function: Property reference

Egg = person (' Egon ', 10,1000) print (egg.name) print (egg.aggressivity) print (Egg.life_value) <br> of course, you can also refer to a method, Because the method is also a property.

　　

Viii. Object-Oriented summary

Fixed format for definition and invocation

Class Name:    def __init__ (self, parameter 1, parameter 2): Self        . Property of the Object 1 = parameter 1 self        . property of Object 2 = parameter 2    def method name (self):p    Method Name 2 (self):p the name  of the #对象就是实例, which represents a specific thing                  #类名 (): Class name + parenthesis is the instantiation of a class, equivalent to invoking the __init__ method                  #括号里传参数, The parameter does not need to pass self, and the other is #结果返回一个对象对象名 corresponding to the formal parameter one by one in Init                  . The object's property 1   #查看对象的属性, directly with the object name. Method Name ()     #调用类中的方法, directly with Object name. Method Name () to

　　

Ix. Interaction between objects

#人狗大战小程序class Person:    def __init__ (self,name,aggr,life_value):        self.name=name        self.aggr=aggr        Self.life_value=life_value    def attack (Self,dog): #人可以攻击狗        dog.life_value=dog.life_value-self.aggrclass Dog :    def __init__ (self,name,aggr,life_value):        self.name = name        Self.aggr = aggr        self.life_value = Life_ Value    def attack (Self,egg): #狗也可以攻击人        egg.life_value = Egg.life_value-self.aggregg = Person (' Egon ', 250,1000 Dog = Dog (' Lele ', 50,2000) print (' The dog did not attack before Egon's health: ', Dog.life_value)  #没攻击前egon的生命值egg. Attack (dog)   # Let Egon go to attack the dog Lele print (' The health of Egon after the dog attack: ', Dog.life_value)  #攻击后egon的生命值print (' Egon didn't attack the dog's health before: ', Egg.life_value)  #没攻击前egon的生命值dog. Attack (egg)   #让狗去攻击egonprint (' The Life of the dog after the Egon attack: ', Egg.life_value)  #攻击后egon的生命值

X. Class namespaces and objects, namespace of the instance

Creating a class creates a namespace for a class that stores all the names defined in the class, which become properties of the class

The class has two properties: static property and dynamic property

• A static property is a variable that is defined directly in the class
• A dynamic property is a method defined in a class

Python full stack development "13th" Python Object-oriented