Python socket only receives input once when using pygame

Question

I am trying to send a message using sockets dependant on the state of my arrow keys, it seems that the first keypress works fine, and then the rest are irrelevant.

Client code:

import socket
import pygame
sender = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
host = '127.0.0.1' #loop back
port = 59769
sender.connect((host,port))
pygame.init()
pygame.display.set_mode((40,40))


while True:
    for event in pygame.event.get():
        if event.type == pygame.KEYDOWN and event.key == pygame.K_LEFT:
            sender.send("2".encode())
        if event.type == pygame.KEYDOWN and event.key == pygame.K_RIGHT:
            sender.send("3".encode())
        if event.type == pygame.KEYDOWN and event.key == pygame.K_UP:
            sender.send("1".encode())
        if event.type == pygame.KEYDOWN and event.key == pygame.K_DOWN:
            sender.send("2".encode())
    pygame.event.pump()
    pygame.display.update()

Server code

import socket
import atexit

#Setup socket
PORT = 59769 #Choose any open port, alternatively choose one in advance
HOST = '0.0.0.0' #listen from any device

serversocket = socket.socket()
serversocket.bind((HOST,PORT))
def exit_handler():
    print("Handling exit...")
    serversocket.close()

print("Socket created at port " + str(serversocket.getsockname()[1]))
#How many devices to listen to
serversocket.listen(1)

#Wait for input
while True:
    connection,address = serversocket.accept()
    received= connection.recv(1024).decode()
    print(received)
    #print("Brightness being set to "+received)
    #print("Brightness succesfully set")

Why does it only work once, and how can I fix it?

Benjamin Hoving · Accepted Answer · 2019-03-16T22:24:45.860

It only works once because you only create one connection to the server. (On line 6 of your client code.) You need to create a new connection for every request.

Client Code:

import socket
import pygame
host = 'localhost' #loop back
port = 59769
pygame.init()
pygame.display.set_mode((250, 250))


def send(data):
    # Create a socket (SOCK_STREAM means a TCP socket)
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
        # Connect to server and send data
        sock.connect((host, port))
        sock.sendall(bytes(data + "\n", "utf-8"))


while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()

        if event.type == pygame.KEYDOWN and event.key == pygame.K_LEFT:
            send('2')
        if event.type == pygame.KEYDOWN and event.key == pygame.K_RIGHT:
            send('3')
        if event.type == pygame.KEYDOWN and event.key == pygame.K_UP:
            send('1')
        if event.type == pygame.KEYDOWN and event.key == pygame.K_DOWN:
            send('2')

    pygame.display.update()

Server Code:

import socketserver

class MyTCPHandler(socketserver.BaseRequestHandler):
    """
    The request handler class for our server.

    It is instantiated once per connection to the server, and must
    override the handle() method to implement communication to the
    client.
    """

    def handle(self):
        # self.request is the TCP socket connected to the client
        self.data = self.request.recv(1024).strip()
        print(self.data.decode())

if __name__ == "__main__":
    HOST, PORT = "0.0.0.0", 59769

    # Create the server, binding to localhost on port 9999
    with socketserver.TCPServer((HOST, PORT), MyTCPHandler) as server:
        # Activate the server; this will keep running until you
        # interrupt the program with Ctrl-C
        server.serve_forever()

More information: (I ripped the server code and the client sending code right from the socketserver docs.)

socket docs

socketserver docs

Works nearly perfectly had to implement __exit__ for the class, otherwise perfect solution, thanks — Fares Al Ghazy, Mar 18 '19 at 20:31

Python socket only receives input once when using pygame

1 Answers1