一、socketserver实现并发编程

　　如下图socketserver模块中包含基于多线程实现并发编程的类和基于多进程的实现并发编程的类，它其实内部的实现的机制是将我们之前学习实现多线程、多进程的过程封装，按照特定的流程就可以使用，其中常用的还是基于tcp协议通信，多线程的用到的模块是ThreadingTCPServer，多进程用到的模块是ForkingTCPServer，需要说明的是socketserver模块中多进程不能在windows系统中实现，因此这里暂时先主要介绍一下基于TCP协议的多线程实现的方式。

　　FTP多用户通信实例：

#服务端import socketserverimport structimport jsonimport osclass FtpServer(socketserver.BaseRequestHandler):    coding='utf-8'    server_dir='file_upload'    max_packet_size=1024    BASE_DIR=os.path.dirname(os.path.abspath(__file__))    def handle(self):        print(self.request)        while True:            data=self.request.recv(4)            data_len=struct.unpack('i',data)[0]            head_json=self.request.recv(data_len).decode(self.coding)            head_dic=json.loads(head_json)            # print(head_dic)            cmd=head_dic['cmd']            if hasattr(self,cmd):                func=getattr(self,cmd)                func(head_dic)    def put(self,args):        file_path = os.path.normpath(os.path.join(            self.BASE_DIR,            self.server_dir,            args['filename']        ))        filesize = args['filesize']        recv_size = 0        print('----->', file_path)        with open(file_path, 'wb') as f:            while recv_size < filesize:                recv_data = self.request.recv(self.max_packet_size)                f.write(recv_data)                recv_size += len(recv_data)                print('recvsize:%s filesize:%s' % (recv_size, filesize))ftpserver=socketserver.ThreadingTCPServer(('127.0.0.1',8080),FtpServer)ftpserver.serve_forever()

import socketimport structimport jsonimport osclass MYTCPClient:    address_family = socket.AF_INET    socket_type = socket.SOCK_STREAM    allow_reuse_address = False    max_packet_size = 8192    coding='utf-8'    request_queue_size = 5    def __init__(self, server_address, connect=True):        self.server_address=server_address        self.socket = socket.socket(self.address_family,                                    self.socket_type)        if connect:            try:                self.client_connect()            except:                self.client_close()                raise    def client_connect(self):        self.socket.connect(self.server_address)    def client_close(self):        self.socket.close()    def run(self):        while True:            inp=input(">>: ").strip()            if not inp:continue            l=inp.split()            cmd=l[0]            if hasattr(self,cmd):                func=getattr(self,cmd)                func(l)    def put(self,args):        cmd=args[0]        filename=args[1]        if not os.path.isfile(filename):            print('file:%s is not exists' %filename)            return        else:            filesize=os.path.getsize(filename)        head_dic={
   'cmd':cmd,'filename':os.path.basename(filename),'filesize':filesize}        print(head_dic)        head_json=json.dumps(head_dic)        head_json_bytes=bytes(head_json,encoding=self.coding)        head_struct=struct.pack('i',len(head_json_bytes))        self.socket.send(head_struct)        self.socket.send(head_json_bytes)        send_size=0        with open(filename,'rb') as f:            for line in f:                self.socket.send(line)                send_size+=len(line)                print(send_size)            else:                print('upload successful')client=MYTCPClient(('127.0.0.1',8080))client.run()

　　上例中实现并发多线程是在服务端，主要实现见如下多用户通信实例：

　　服务端：

import socketserverclass Myserver(socketserver.BaseRequestHandler):                         #必须创建一个类，并继承socketserver.BaseRequestHandler类    def handle(self):                                                    #这个方法必须有，而且方法名不可以更改，它是实例创建连接后自动执行的方法        while True:            data=self.request.recv(1024)                                 #self.request相当于conn            if not data:break            self.request.send(data.upper())if __name__ == '__main__':    server=socketserver.ThreadingTCPServer(('127.0.0.1',8090),Myserver)  #实例化一个对象    server.serve_forever()                                               #循环建立连接

　　客户端：

import socketclient=socket.socket(socket.AF_INET,socket.SOCK_STREAM)client.connect(('127.0.0.1',8090))while True:    msg=input('>>>').strip()    if  not msg:        continue    client.send(msg.encode())    data=client.recv(1024)    print(data.decode())