Question

我正在使用python进行简单的应用程序，它可以使用套接字并使用UDP协议。我有一个client.py和server.py。我想在无限循环中从客户端向服务器发送消息，并从服务器捕获resive消息。为了做到这一点，我有以下代码：

server.py

import socket

serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = "127.0.0.1"
port = 8000
print(host)
print(port)
serversocket.bind((host, port))

serversocket.listen(5)
print('server started and listening')
while 1:
    (clientsocket, address) = serversocket.accept()
    print("connection found!")
    data = clientsocket.recv(1024).decode()
    print(data)
    r = 'I can hear you by UDP!!!!'
    clientsocket.send(r.encode())

client.py

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = "127.0.0.1"
port = 8000
addr = (host, port)
s.connect(addr)


def send(user_input):
    s.sendto(user_input.encode(), addr)
    data = s.recv(1024).decode()
    print('Server tell that: ', data)


while 1:
    if input('Exit? (y/n)') == 'y':
        break
    i = input('>> ')
    send(i)

s.close()

它工作正常，但是当我第二次尝试发送消息时，我的程序会在线停止

s.sendto(user_input.encode(), addr)

我不明白这一刻发生了什么。

Answer 1

如果您想为UDP构建服务器/客户端，则需要仔细阅读文档，以防止使用面向连接协议的API。

以下是UDP的一个工作示例 :(我在代码中添加了一些注释，然后您将看到调整它们的原因）。

服务器

对于一个UDP服务器，您需要使用一个套接字socket.SOCK_DGRAM而不是SOCK_STREAM进行初始化，然后绑定您想要的端口。

import socket #The type of communications between the two endpoints, typically SOCK_STREAM for connection-oriented protocols and SOCK_DGRAM for connectionless protocols. serversocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) host = "127.0.0.1" port = 8000 print(host) print(port) serversocket.bind((host, port)) #serversocket.listen(5) #--This method sets up and start TCP listener. print('server started and listening') while 1: #(clientsocket, address) = serversocket.accept() #---This passively accept TCP client connection, waiting until connection arrives (blocking) #print("connection found!") #data = clientsocket.recv(1024).decode() #This method receives TCP message data, addr = serversocket.recvfrom(2048) print(data) r = 'I can hear you by UDP!!!!' serversocket.sendto(r.encode(), addr) serversocket.close()

<强>客户端：

对于一个UDP客户端，您需要使用socket.SOCK_DGRAM而不是SOCK_STREAM初始化一个套接字，然后使用sendto将数据发送到服务器。

import socket #The type of communications between the two endpoints, typically SOCK_STREAM for connection-oriented protocols and SOCK_DGRAM for connectionless protocols. s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) host = "127.0.0.1" port = 8000 addr = (host, port) #s.connect(addr) #---This method actively initiates TCP server connection. def send(user_input): s.sendto(user_input.encode(), addr) data = s.recvfrom(1024).decode() print('Server tell that: ', data) while 1: if input('Exit? (y/n)') == 'y': break i = input('>> ') send(i) s.close()

有关详细信息：

检查Python Socket

首次连接后，Python UDP套接字无效

1 个答案: