Object-oriented Python learning series

Overview

First, the Python programming method

1. Process-oriented programming: Based on business logic from top to bottom lei code
2. Function-oriented programming: Encapsulates a function code into a function, which can be called directly in the future without having to write again
3. Object-oriented Programming: classifying and encapsulating functions

Second, process-oriented programming

 while True:     if CPU utilization > 90%:        # Send mail reminder to         Connect mailbox server        send        mail close connection      If hard disk use space >90%        :# Send mail reminder to         Connect mailbox server to        send mail        Close Connection      if memory consumption > 80%:        # send mail reminder         Connection Mailbox server        send mail        close connection 

Three, function-oriented programming

defSend mail (content)#Send an email reminderConnect mailbox server send mail close connection whileTrue:ifCPU Utilization > 90%: Send mail ('CPU Alarms')     ifHDD Use space > 90%: Send mail ('HDD Alarm')     ifMemory Footprint > 80%: Send mail ('Memory Alarms')

Object-oriented simple application

First, object-oriented overview

Object-oriented is a way of programming, which requires "class" and "object" in the way of programming, and object-oriented is actually the operation of classes and objects.

Second, create a class

############# #创建类classFoo:defBar (self):Print('Bar')     defHello (self, name):Print('I am%s'%name)############# #实例化obj =Foo () obj. Bar ()#Execute Bar MethodObj. Hello ('Wupeiqi')#Execute the Hello method

Iii. Object-oriented self-explanation

Self is a formal parameter, when executing obj1 = Foo (' Alex ', 19), Self equals obj1

When executing obj2 = Foo (' Eric ', 20), self equals obj2

Self=obj

three characteristics of object-oriented

I. Object-oriented encapsulation

Overview:

Encapsulation is the encapsulation of content to a place, and then to call the encapsulated content

A simple example

############## #代码classFoo:def __init__(Self, name, age):#called a construction method that automatically executes when an object is created according to a classSelf. Name =name self. Age= Agedefinfo (self):Print("""My name is:%s My age is:%d"""%(self.) Name, self. Age)) Ansheng= Foo ("Alex", 18)#package Alex and 18 into the name and age propertiesansheng.info () xiaoming= Foo ("Eric", 30)#encapsulates Eric and 30 into the name and age propertiesXiaoming.info ()############## #结果My Name is: Anshengmy Age is: 18My name is: Xiaomingmy Age is: 30

Second, the object-oriented inheritance

Overview:

Inheritance is the child can inherit the content of the parent, so for the inheritance, is actually the multiple classes common methods extracted into the parent class, the subclass only need to inherit the parent class and do not need one by one to implement each method

A simple example

Create a class of ' people ' information, such as people have limbs, hair, eyes, ears, so write this into a class; In creating a class of Chinese and foreigners, the Chinese language is Chinese, the skin is yellow; the language of the foreigner is English, the skin is black.

###################### #代码classpeople:def __init__(self):Print("""your general features are: limbs, hair, eyes, ears""")classChina (people):definfo (self):Print("""you are Chinese, your language is Chinese, the skin is yellow""")classUs (people):definfo (self):Print("""You are an American, your language is English, the skin is black""") C=China () C.info () m=Us () m.info ()####################### #结果your general characteristics are: limbs, hair, eyes, ears you are Chinese, your language is Chinese, the skin is yellow your general characteristics are: limbs, hair, eyes, ears you are American, your language is English, the skin is black

Parent class or subclass

base class or derived class

1. Derived classes can use all the methods in the base class

2. If the derived class and the base class exist at the same time, the derived class is preferred

Multiple-inheritance lookup order in inheritance

Top class Two classes without a parent class in case

Top class Two classes with a parent class in case

members of the class

Classification of members of a class

Second, the field

Normal field: Belongs to object, called by object

static field: Belongs to class called through class

############### #代码:classProvince:country="China"        #static fields, the function is to write the same fields here, saving memory, through the class to get the properties. When the code is loaded, it has been created    def __init__(self,name): Self.name= Name#normal fieldHN= Province ('Henan')#creating an object from a classPrint(Hn.name)#calling normal fieldsPrint(Province.country)#calling a static field############### #结果:Henan China

Third, the method

Common method: Called by an object, requires at least one self parameter

static method: Called by class with no default parameters

Function: A static method is required if you want to write only a normal function.

Class method: Called by the class, requires at least one CLS parameter

Role: Get the class name

############################## Code:classProvince:def __init__(self,name): Self.name=namedefShow (self):#normal method, called by the object to execute        Print('Common Methods') @staticmethoddefF1 (ARG):#static methods, which are executed through a class call. The function is: if you want to write a normal function, write the static method, do not need self (this is equivalent to the normal function)        Print(ARG) @classmethoddefF2 (CLS):#Class method, which executes through the class call. The function is: can get the class name        Print(CLS) HN= Province ('Henan')#creating an object from a classHn.show ()#calling the normal methodPROVINCE.F1 ('Static Methods')#calling a static methodPROVINCE.F2 ()#Calling class methods########################## # #结果:Common method static method<class '__main__. Province'>

Member modifiers for class

First, overview:

There are two types of members for each class

• Public members: accessible from anywhere
• Private members: Only within the class can access

Ii. defining and invoking private static fields

######################################### #代码classFoo:__classmembers="of Private"  #private static fields    defMembers (self):#output by calling a private static field from a method in a class        Print(Foo.)__classmembers) obj= Foo ()#Create an ObjectObj. Members ()#the members method in the execution class######################################### #结果Privately owned

Third, define and invoke private normal fields

################################## #代码classFoo:def __init__(Self, URL):#How to construct a classSelf.__blog= URL#Private Normal field        Print(self.)__blog)#directly in the paparazzi method does not output the incoming URLobj= Foo ("www.baidu.com")#create an object, pass in a value################################## #结果Www.baidu.com

Object-oriented Python learning series