如果数据未接收且数据长度在python [TCP]中未知，如何打破while循环

Question

我是python和socket编程的新手。我正在尝试将数据发送到客户端，并且数据的长度未知。在客户端接收到所有数据后，由于while循环，程序没有终止（参见下面的代码）。我也使用命令（如果不是消息：break），但它也无法正常工作。第二个是丢包问题。当我不给时间。 Sleep（）在发送方，然后接收方丢失一些数据包（不接收发送方发送所有数据包的接收方的所有数据包）。如何在没有sys.exit命令的情况下从while循环中出来？和....如何在不使用time.sleep函数的情况下处理第二个问题。如果有人可以帮助我，这是值得赞赏的。谢谢

[接收节点]

import socket
import os,sys


def frame_reception_function ():
    while True:
        PORT = 123
        s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
        s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
        s.bind(('',PORT))
        s.listen()
        conn,address=s.accept()
        message=conn.recv(4096).decode()
        print (message)
        conn.close()
frame_reception_function()

[发送节点]

import os,sys
import socket
import time


MyNeighborSet_ip= ['192.168.1.2']


Data_transfer_listt = [['192.168.1.1', '192.168.1.2'], ['192.168.1.2', '192.168.1.3'], ['192.168.1.2', '192.168.1.4'], ['192.168.1.4', '192.168.1.5'], ['192.168.1.4', '192.168.1.6']]



def sending_Neighobr_ip_list():    
    #nn1=n1
    message='Neighbor_list_sending'
    #print (len(Data_transfer_listt))

    for i in range(len(Data_transfer_listt)):
        receiver_ip=Data_transfer_listt[i][0]
        receiver_node_list=Data_transfer_listt[i][1]
        T_message= message + ";" + receiver_ip + ";" + receiver_node_list
        T_message_bytes= bytes(T_message,'utf-8')
        PORT = 123
        print ("just after socket")
        for k in range (len(MyNeighborSet_ip)):
            s=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
            s.connect((MyNeighborSet_ip[k],PORT))
            s.sendall (T_message_bytes) 
            s.close()
            time.sleep(0.01)


sending_Neighobr_ip_list()

Answer 1

保持打开和关闭套接字是非常耗费资源的，我将把它们从while循环中取出。另外，我不记得recv是否具有阻止功能。但这应该可以帮助你正确地摆脱while循环并解决你的第一个问题。

接收器：

def frame_reception_function ():
    data = []
    PORT = 123
    s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
    s.bind(('0.0.0.0',PORT))
    s.listen(1)
    conn,address=s.accept()  # accept an incoming connection using accept() method which will block until a new client connects
    while True:
        datachunk=conn.recv(1024) # reads data chunk from the socket in batches of 4086 bytes using method recv() until it returns an empty string
        if not datachunk:
            break  # no more data coming in, so break out of the while loop
        data.append(datachunk)  # add chunk to your already collected data

    conn.close()
    print(data)
    return

frame_reception_function()

发件人：

import os,sys
import socket
import time

MyNeighborSet_ip= [&ltTHE IP ADDRESS OF YOUR RECEIVER&gt]

Data_transfer_listt = [['192.168.1.1', '192.168.1.2'], ['192.168.1.2', '192.168.1.3'], ['192.168.1.2', '192.168.1.4'], ['192.168.1.4', '192.168.1.5'], ['192.168.1.4', '192.168.1.6']]

def sending_Neighobr_ip_list():
    #nn1=n1
    message='Neighbor_list_sending'
    #print (len(Data_transfer_listt))
    PORT = 123

    for k in range (len(MyNeighborSet_ip)): 
        s=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((MyNeighborSet_ip[k],PORT))
        s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)

        for i in range(len(Data_transfer_listt)):
            receiver_ip=Data_transfer_listt[i][0]
            receiver_node_list=Data_transfer_listt[i][1]
            T_message= message + ";" + receiver_ip + ";" + receiver_node_list
            T_message_bytes= bytes(T_message)

            print("sending message")
            s.sendall (T_message_bytes)

        s.close()

sending_Neighobr_ip_list()

对于THE IP ADDRESS OF YOUR RECEIVER，我使用了我的本地IP地址（192.168.x.x）。

这是接收器端的输出：

['Neighbor_list_sending;192.168.1.1;192.168.1.2', 'Neighbor_list_sending;192.168.1.2;192.168.1.3', 'Neighbor_list_sending;192.168.1.2;192.168.1.4', 'Neighbor_list_sending;192.168.1.4;192.168.1.5', 'Neighbor_list_sending;192.168.1.4;192.168.1.6']

问题出在发送方，你每次迭代都关闭套接字。这使接收器也关闭了它的连接。因此，发送方成功发送第一条消息，然后第二条连接上的错误导致接收方已关闭且未查找连接。相反，切换for循环顺序。首先建立连接，然后发送消息，然后关闭连接。