Python之socket_tcp

1.1socket编程之tcp编程

"""
socket类型
sock_stream 面向连接的流套接字，默认值 tcp协议
sock_dgram  无连接的数据报文套接字，udp协议
"""
import socket
s = socket.socket()
s.bind(('127.0.0.1',9999))  #bind接受一个2元祖
s.listen()
"""
Accept a connection. The socket must be bound to an address and listening for connections.
The return value is a pair (conn, address) where conn is a new socket object usable to send and receive data on the connection, 
and address is the address bound to the socket on the other end of the connection
"""
new_socker,info = s.accept() #只接受一个client请求，阻塞
data=new_socker.recv(1024)　　#阻塞
print(data)
print(type(data))
new_socker.send('back {}'.format(data).encode())
s.close()　　

 例子

有阻塞就要尽量放到线程中去执行，不要影响主线程

import socket
server = socket.socket()
server.bind(('127.0.0.1',9999))
server.listen()
'''
建立一个client，socket连接之后，只能发一次数据
在accept出阻塞，需要建立第二个连接
'''
while True:
    new_socket,ip = server.accept()
    data = new_socket.recv(1024)
    new_socket.send('ck test {}'.format(data).encode())

 socket群聊实例

import socket
import threading

class ChatTcpServer:
    def __init__(self,ip,port):
        self.ip = ip
        self.port = port
        self.cliets = {}
        #实例化就创建一个socket对象
        self.socket = socket.socket()
    def start(self):
        self.socket.bind((self.ip,self.port))
        self.socket.listen()
        threading.Thread(target=self._accept,name="_aceept").start()

    def _accept(self):  #只开启一个accept线程，连接产生的new_socket负责和线程receive同信
        while True:
            print('1~~~~~~~~~~~~~~~~~~~',threading.enumerate())
            new_socket,raddr = self.socket.accept()    #阻塞主线程，所以开启一个工作线程receive
            threading.Thread(target=self._receive,name="reveive",args=(new_socket,)).start()
            self.cliets[new_socket] = raddr
            print(self.cliets)
            print(type(self.cliets.keys()))

    def _receive(self,new_socket): #客户端连接几个socket 就开几个receive线程
        while True:
            print('2~~~~~~~~~~~~~~~~~~~',threading.enumerate())
            data = new_socket.recv(1024)               #阻塞
            for k in self.cliets.keys():
                k.send('ack {}'.format(data).encode())

    def stop(self):
        for s in self.cliets.values():
            s.close()
        self.socket.close()


if __name__ == '__main__':
    cs = ChatTcpServer('127.0.0.1',9999)
    cs.start()
    # print('3~~~~~~~~~~~~~~~~~~~',threading.enumerate())
    # cs.stop()
problem：there has a error when cliens exit
ConnectionAbortedError

import socket
import threading

class ChatTcpServer:
    def __init__(self,ip,port):
        self.ip = ip
        self.port = port
        self.cliets = {}
        #实例化就创建一个socket对象
        self.socket = socket.socket()
        self.event = threading.Event()
    def start(self):
        self.socket.bind((self.ip,self.port))
        self.socket.listen()
        threading.Thread(target=self._accept,name="_aceept").start()

    def _accept(self):  #只开启一个accept线程，连接产生的new_socket负责和线程receive同信
        while not self.event.is_set():
            new_socket,raddr = self.socket.accept()    #阻塞主线程，所以开启一个工作线程receive
            threading.Thread(target=self._receive,name="reveive",args=(new_socket,)).start()
            self.cliets[new_socket] = raddr
            print(self.cliets)
            print(type(self.cliets.keys()))

    def _receive(self,new_socket): #客户端连接几个socket 就开几个receive线程
        while not self.event.is_set():
            data = new_socket.recv(1024)               #阻塞
            for k in self.cliets.keys():
                k.send('ack {}'.format(data).encode())

    def stop(self):
        if self.cliets:
            for s in self.cliets.values():
                s.close()
        self.socket.close()
        self.event.set()


if __name__ == '__main__':
    cs = ChatTcpServer('127.0.0.1',9999)
    cs.start()
    while True:
        cmd = input("please set stop:>>>")
        if cmd == 'quit':
            cs.stop()
            break

以上版本服务端可以断开连接，但是客户端断开连接抛出异常　

增加客户端断开命令

客户端主动断开连接的问题，服务端知道自己何时断开
如果是客户端断开服务器不知道，所有好的做法客户端发出特殊消息通知服务器断开连接，但是客户端主动断开服务端主动发送一个空消息，超时返回异常，捕获异常并清理连接，即使为客户端提供了断开命令，也不能保证客户端会使用它断开连接，还是要增加这个退出功能

    def _receive(self,new_socket): #客户端连接几个socket 就开几个receive线程
        while not self.event.is_set():
            data = new_socket.recv(1024)               #阻塞
            if data == b"quit":
                self.cliets.pop(new_socket)
                new_socket.close()
                break
            for k in self.cliets.keys():
                k.send('ack {}'.format(data).encode())

 socket常用方法

socket = socket.socket()
socket.recv(1024) bufsize=1024 获取数据，默认是阻塞状态
socket.recvfrom(1024)   获取数据，返回一个二元组(bytes,address)
socket.recv_into(buffer=1024,nbytes=10,flags=None) 获取到nbytes的数据后，存储到buffer中，如果nbytes没有指定或者0，将buffer大小的数据存入buffer中，返回接收的字节数
socket.send(bytes)  tcp发送设备
socket.sendall(bytes)   tcp发送全部设备，成功返回None

 Makefile

socket.socket().makefile(mode='r',buffering=None)   创建一个与该套接字相关联的文件对象，将recv方法看作读方法，将send方法看作写方法

socket.getpeername()    返回连接套接字的远程地址，返回值通常是元组（ipaddr,port）
sockete.getsockname()    返回套接字自己的地址，通常是一个元祖(ipaddr,port)
socket.setbloking(flag)    如果flag为0则将套接字设为非阻塞模式，否则将套接字设为阻塞模式(默认值）
非阻塞模式下，如果调用recv没有发现任何数据，或send()调用无法立即发送数据，那么将引起socket.error异常
socket.settimeout(value)    设置套接字操作的超时期，timeout是一个浮点数单位秒
值为none表示没有超时期，一般超时期应该在刚创建套接字时设置，因为他们可能用于连接的操作(connect())

 read和readline(行读取，包括换行符)

import socket
socket = socket.socket()
socket.bind(('127.0.0.1',9999))
socket.listen()

while True:
    new_socket,raddr = socket.accept()
    f = new_socket.makefile('rw')
    print(f)
    line = f.readline()  #Read and return one line from the stream
    line = f.read(10)   #Read up to n bytes from the object and return them
    #只有输入十个字节才会return
    print(line)
    f.write('ack {}'.format(line))
    f.flush()
f.close()

client编写

import socket
socket = socket.socket()
socket.bind(('127.0.0.1',9999)) #server ip
socket.listen()

new_socket,raddr = socket.accept()
data = new_socket.recv(1024)
print(data)
new_socket.send('ack {}'.format(data).encode())

import socket
import threading
import datetime
import logging

FORMAT = '%(asctime)s %(threadName)s %(thread)d %(message)s'
logging.basicConfig(level=logging.INFO,format=FORMAT)

class ChatClient:
    def __init__(self,ip='127.0.0.1',port=9999):
        self.ip = ip
        self.port = port
        self.sock =socket.socket()
        self.event = threading.Event()

    def start(self):
        self.sock.connect((self.ip,self.port))
        self.send('i am ready')
        threading.Thread(target=self.receive,name='receive').start()


    def receive(self):
        while not self.event.is_set():
            try:  #连接不成功，捕获异常
                data = self.sock.recv(1024)
                logging.info(data)
            except Exception as e:
                logging.info(e)

    def send(self,msg:str):
        self.sock.send('{}'.format(msg).encode())


    def stop(self):
        self.sock.close()
        self.event.set()
        logging.info('Client stops')

def main():
    cc = ChatClient()
    cc.start()
    while True:
        cmd = input("please set a number:")
        if cmd.strip() == b'quit':
            cc.stop()
            break
        cc.send(cmd)

if __name__ == '__main__':
    main()