Python Development Learning-day07 (object-oriented polymorphism, class method, reflection, new class and Legacy class, socket programming)

S12-20160227-day07

Pytho Automation Development day07date:2016.02.27

    @南非波波

Course Outline:

Day06

Http://www.cnblogs.com/alex3714/articles/5188179.html

Day07

Http://www.cnblogs.com/alex3714/articles/5213184.html

I. Polymorphism and inheritance of classes

Polymorphism of the class: Unified interface Invocation

#!/usr/bin/env python# -*- coding:utf-8 -*-class Animal:    def __init__(self, name):    # Constructor of the class        self.name = name    def talk(self):              # Abstract method, defined by convention only        raise NotImplementedError("Subclass must implement abstract method")    hobbie = ‘ddd‘class Cat(Animal):    def talk(self):        return ‘Meow!‘class Dog(Animal):    def talk(self):        return ‘Woof! Woof!‘animals = [Cat(‘Missy‘),           Dog(‘Lassie‘)]for animal in animals:    print(animal.name + ‘: ‘ + animal.talk())

Methods of the class: example

#!/usr/local/env Python3 "author:@ South Africa bobo Blog:http://www.cnblogs.com/songqingbo/e-mail:[email protected]" Class Animal (object): ' Defines an animal class ' Def __init__ (self,name): self.name = name Self.__num = Non E #定义成私有变量, can only be accessed in the class # Def talk (self): # print ("%s is talking!"% self.name) Hobbie = "Shen" #类变量, static fields @clas Smethod #类方法, cannot access instance variable def talk (self): print ('%s is talking! '% self.hobbie) # def work (self): # print    ("%s is working!"% self.name) @staticmethod #静态方法, cannot access class variables and instance variables def work (): Print ("It is working!") # def walk (self): # print ("%s is walking!"% self.name) @property #把方法编程静态属性 def Walk (self,num): retur  n self.__num @walk. Setter #传值 def Walk (self,num): Self.__num = num print (self.__num) @walk. deleter #删值 def Walk (self): print ("del num") c = Animal ("swht") # C.talk () # c.work () C.walk = 3del C.walkprint ("Out:", c._a Nimal__num) #特例情况下可以通过这种方式访问私有变量

Classic class and Modern class

Classic class and new class differences:

Classic class: Inherit with depth precedence new class: Inherit with breadth precedence

In addition: Classic class and New class in Python-3. The X platform will default to the use of breadth-first inheritance, while in Python-2. This difference is reflected in X

Example code:

#!/usr/local/env python3‘‘‘Author:@南非波波Blog:http://www.cnblogs.com/songqingbo/E-mail:[email protected]‘‘‘class A:    print("A")    def f2(self):        print("f2 from A")class B(A):    print("B")    def f1(self):        print("f1 from B")    def f2(self):        print("f2 from B")class C(A):    print("C")    def f2(self):        print("f2 from C")class D(B,C):    passd = D()d.f1()d.f2()‘‘‘广度优先算法继承。先将B类中的f2()注释掉，D自动继承C.f2()，如果再将C类中的f2()，D自动继承A.f2()‘‘‘

Special members of the class

Example:

#!/usr/local/env python3‘‘‘Author:@南非波波Blog:http://www.cnblogs.com/songqingbo/E-mail:[email protected]‘‘‘class People(object):    ‘‘‘    定义一个人类    ‘‘‘    def __init__(self,name,age):        ‘‘‘        定义属性        :param name: 人类的名字        :param age: 人类的年龄属性        :return:        ‘‘‘        self.name = name        self.age = age    def china_man(self):        passchinese = People("swht",27)#__doc__:查看类的注释print(chinese.__doc__) #  定义一个人类#__dict__:以字典的形式显示类对象中的成员。使用场景：查看类中有多少成员（只显示类变量，不显示实例变量）print(chinese.__dict__) #{‘age‘: 27, ‘name‘: ‘swht‘}#__module__:表示当前操作的对象在那个模块print(chinese.__module__) #__main__#__class__:表示当前操作的对象的类是什么print(chinese.__class__) #<class ‘__main__.People‘>

Methods for constructing classes

Http://stackoverflow.com/questions/100003/what-is-a-metaclass-in-python

A sentence constructs a class

Foo = type(‘Foo‘,(object,), {‘func‘: func})     #type第一个参数：类名    #type第二个参数：当前类的基类    #type第三个参数：类的成员

Reflection method

Hasattr: Determines whether the specified input method exists in the instance

hasattr(server,sys.argv[1])  返回值是布尔型 True or False

GetAttr: Getting methods in an instance

func = getattr(server,sys.argv[1])  获取对象方法的内存地址

SetAttr: Setting a custom method to a specific instance to use

setattr(server,‘run‘,test_run) 将特定方法test_run绑定给实例server，并重命名为run方法server.run()  实例server可以指定调用方法run

Delattr: Delete the instance's member variable or the method of the class, cannot delete the instance's method

#delattr可以删除类的方法、实例的成员变量# delattr(server,‘start‘) #尝试删除实例的方法是错误的# delattr(server,"host") #删除实例的变量# delattr(Webserver,‘start‘)# server.start() #AttributeError: ‘Webserver‘ object has no attribute ‘start‘

Complete Sample code:

#!/usr/local/env Python3 "author:@ South Africa bobo Blog:http://www.cnblogs.com/songqingbo/e-mail:[email protected]"        Import Sysclass Webserver (object): ' Define a Web server to start, close class ' Def __init__ (self,host,port): ' Initialize class:p Aram Host: Host address:p Aram Port: Host port number: return: "' Self.host = host SELF.P    ORT = Port def start (self): "Service startup method: return:" ' Print ("Services is starting ...") def stop (self): "Service Stop Method: return:" Print ("service is stopping ...") def rest Art (self): "Service Restart Method: return: ' ' Self.stop () Self.start () #定义一个特殊运行的函数, bound to instance Ser Ver go up def test_run (): Print ("Test run ...") Server = Webserver ("localhost", +) if Hasattr (Server,sys.argv[1]): func = Getatt R (Server,sys.argv[1]) func () #setattr主要作用是将一个单独定义的函数添加到实例中, the function does not take effect for a class or other instance setattr (server, ' run ', Test_run) Server.run () #delattr可以删除类的方法, member variable of instance # delattr (sErver, ' start ') #尝试删除实例的方法是错误的 # delattr (server, "host") #删除实例的变量 # delattr (Webserver, ' start ') # Server.start () # Attributeerror: ' Webserver ' object has no attribute ' start '

Second, Socket network programming

Simple implementation of C/s Interactive example:

Example code:

实现简单的client与server端数据交互（一句话）

Socket_server

#!/usr/local/env python3‘‘‘Author:@南非波波Blog:http://www.cnblogs.com/songqingbo/E-mail:[email protected]‘‘‘import socketip_port = ("127.0.0.1",5000)sk = socket.socket()sk.bind(ip_port)sk.listen(5)while True:    print("南非波波server is Listening....")    conn,addr = sk.accept()    client_data = conn.recv(1024)    print(str(client_data,"utf8"))    conn.sendall(bytes("落花不是无情物，化作春泥更护花！","utf8"))    conn.close()

Socket_client

#!/usr/local/env python3‘‘‘Author:@南非波波Blog:http://www.cnblogs.com/songqingbo/E-mail:[email protected]‘‘‘import socketip_port = ("127.0.0.1",5000)sk = socket.socket()sk.connect(ip_port)sk.sendall(bytes("夕阳无限好，只是近黄昏","utf8"))server_reply = sk.recv(1024)print(str(server_reply,"utf8"))sk.close()

Improve code 1:

实现多个client与server进行串行交互

Socket-server1

#!/usr/local/env python3‘‘‘Author:@南非波波Blog:http://www.cnblogs.com/songqingbo/E-mail:[email protected]‘‘‘import socketip_port = ("127.0.0.1",5000)sk = socket.socket()sk.bind(ip_port)sk.listen(5)while True:    print("南非波波server is Listening....")    conn,addr = sk.accept()    client_data = conn.recv(1024)    print(str(client_data,"utf8"))    # conn.sendall(bytes("落花不是无情物，化作春泥更护花！","utf8"))    while True:        try:            client_data = conn.recv(1024)            if not client_data:                break            print("recv:",str(client_data,"utf8"))            conn.send(client_data)        except Exception:            print("客户端断开!")            break    conn.close()

Socket-client1

#!/usr/local/env python3‘‘‘Author:@南非波波Blog:http://www.cnblogs.com/songqingbo/E-mail:[email protected]‘‘‘import socketip_port = ("127.0.0.1",5000)sk = socket.socket()sk.connect(ip_port)# sk.sendall(bytes("夕阳无限好，只是近黄昏","utf8"))server_reply = sk.recv(1024)print(str(server_reply,"utf8"))while True:    client_data = input(">>:").strip()    if not client_data:        continue    if client_data == ‘q‘:        break    sk.send(bytes(client_data,"utf8"))    print(client_data)sk.close()

Final code:

实现简单的ssh命令交互，获取Linux系统的相关信息

Socket-server2

#!/usr/local/env Python3 "author:@ South Africa bobo Blog:http://www.cnblogs.com/songqingbo/e-mail:[email protected]" Import Socketimport Subprocessip_port = ("127.0.0.1", "") #定义服务监听的ip地址和端口ssh = Socket.socket () ssh.bind (ip_port) # Address and port Binding Ssh.listen (5) #设定做多5个并发连接while True:print ("South Africa Bobo server is waiting ...") conn,addr = Ssh.accept () while Tr            Ue:client_data = Conn.recv (1024x768) #介绍client发过来的数据, maximum receive byte if not client_data: #如果client_data为空, jump out of loop Break cmd = str (client_data, "UTF8") #获取client_data数据并进行类型和编码转换 print ("Server recv:", cmd) cmd_ Call = subprocess. Popen (cmd,shell=true,stdout=subprocess. PIPE) #以原生shell命令的形式指定client的强求指定 and output the result to cmd_result Cmd_result = Cmd_call.stdout.read () If Len (cmd_result) =        = 0: #如果命令没有结果返回, you need to return a prompt to the client, otherwise the console will block Cmd_result = B "cmd execution has no output ..." #client不能一次性接收过多的数据包, the server is required to tell the client how much data needs to be transferred. It is then received separately by the client side ack_msg = bytes ("cmd_result_size|%s"% Len (cmd_resuLT), "UTF8") #发送数据传输认证标志 conn.send (ack_msg) Client_ack = Conn.recv () if client_ack.decode () = = ' Clie Nt_ready_to_recv ': Conn.send (Cmd_result) #数据传输 conn.close ()

Socket-client2

  #!/usr/local/env Python3 "author:@ South Africa Bobo blog:http://www.cnblogs.com/songqingbo/e-mail:[email  Protected] "Import Socketip_port = (" 127.0.0.1 "," ssh_client "= Socket.socket () ssh_client.connect (Ip_port) while        True:user_input = Input ("ssh-client:"). Strip () If Len (user_input) = = 0:continue if user_input = ' Q ': Break Ssh_client.send (Bytes (user_input, ' UTF8 ')) #ack_msg = B "cmd_result_size|%s"% len (cmd_result) Server_ac    K_msg = SSH_CLIENT.RECV (+) cmd_res_msg = str (Server_ack_msg.decode ()). Split ("|") If cmd_res_msg[0] = = "Cmd_result_size": cmd_res_size = Int (cmd_res_msg[1]) ssh_client.send (b "client_ready_to _recv ") res = ' Received_size = 0 while received_size < Cmd_res_size:server_data = SSH_CLIENT.RECV (50 0) Received_size + = Len (server_data) Res + = str (Server_data.decode ()) Else:print (res) prin T ("-----------recv Don----------") ssh_client.close ()  

Python Development Learning-day07 (object-oriented polymorphism, class method, reflection, new class and Legacy class, socket programming)