UDP is a connectionless protocol. This means that peers sending messages do not require establishing a connection before sending messages. socket.recvfrom
thus returns a tuple (msg
[the message the socket received], addr
[the address of the sender])
A UDP server using solely the socket
module:
from socket import socket, AF_INET, SOCK_DGRAM
sock = socket(AF_INET, SOCK_DGRAM)
sock.bind(('localhost', 6667))
while True:
msg, addr = sock.recvfrom(8192) # This is the amount of bytes to read at maximum
print("Got message from %s: %s" % (addr, msg))
Below is an alternative implementation using socketserver.UDPServer
:
from socketserver import BaseRequestHandler, UDPServer
class MyHandler(BaseRequestHandler):
def handle(self):
print("Got connection from: %s" % self.client_address)
msg, sock = self.request
print("It said: %s" % msg)
sock.sendto("Got your message!".encode(), self.client_address) # Send reply
serv = UDPServer(('localhost', 6667), MyHandler)
serv.serve_forever()
By default, sockets
block. This means that execution of the script will wait until the socket receives data.