同时发送/接收消息socket python

Question

I have been working on a simple python socket chat room where the client and server can send messages to each other. The issue that I came across was that the server and client can only send one message at a time. I want it to work like any other chat room, where I could receive a message when I am sending a message, any help will help greatly

Server.py

import socket
import sys

s = socket.socket()
host = socket.gethostname()
print(" server will start on host : ", host)
port = 8080
s.bind((host,port))
name = input(str("Please enter your username: "))
print("")
print("Server is waiting for incoming connections")
print("")
s.listen(1)
conn, addr = s.accept()
print("Recieved connection")
print("")
s_name = conn.recv(1024)
s_name = s_name.decode()
print(s_name, "has joined the chat room")
conn.send(name.encode())

while 1:
    message = input(str("Please enter your message: "))
    conn.send(message.encode())
    print("Sent")
    print("")
    message = conn.recv(1024)
    message = message.decode()
    print(s_name, ":" ,message)
    print("")

Client.py

import socket
import sys

s = socket.socket()
host = input(str("Please enter the hostname of the server : "))
port = 8080
s.connect((host,port))
name = input(str("Please enter your username : "))
print(" Connected to chat server")

s.send(name.encode())
s_name = s.recv(1024)
s_name = s_name.decode()
print("")
print(s_name, "has joined the chat room ")

while 1:
    message = s.recv(1024)
    message = message.decode()
    print(s_name, ":" ,message)
    print("")
    message = input(str("Please enter your message: "))
    message = message.encode()
    s.send(message)
    print("Sent")
    print("")

Answer 1

CaSper has given me the server code where multiple clients can connect to the server but the problem now is that the clients can not talk to each other …

That's primarily because your client wants s_name = s.recv(1024) , while CaSper's server doesn't send its name. Here's a variant of your client (expecting host and port as command arguments) which works with CaSper's server and also addresses your original issue ( client can only send one message at a time ) by using separate threads:

import socket
import sys

s = socket.socket()
s.connect((sys.argv[1], int(sys.argv[2])))
name = input(str("Please enter your username : "))
print(" Connected to chat server")
s.send(name.encode())

def receive_and_print():
    for message in iter(lambda: s.recv(1024).decode(), ''):
        print(":", message)
        print("")
import threading
background_thread = threading.Thread(target=receive_and_print)
background_thread.daemon = True
background_thread.start()

while 1:
    s.send(input("Please enter your message: ").encode())
    print("Sent")
    print("")

Note that CaSper's server has a series of deficiencies:

1. Even now that your clients can send messages at any time, the server waits for a message from one by one client, ie when it waits for client A, client B can send a message, but the server receives and broadcasts it only after client A has sent something.
2. It doesn't handle client disconnects.
3. It goes into a busy loop when all clients disconnected.

For a better server example, see the question Handle multiple requests with select .

… could you possibly change my server so that it works …

Here's a variant of your server which works with this client, also using separate threads for input and reception:

import socket
import sys

s = socket.socket()
host = socket.gethostname()
print(" server will start on host : ", host)
port = 8080
s.bind((host,port))
name = input(str("Please enter your username: "))
print("")
print("Server is waiting for incoming connections")
print("")
s.listen(1)
conn, addr = s.accept()
print("Recieved connection")
print("")
s_name = conn.recv(1024)
s_name = s_name.decode()
print(s_name, "has joined the chat room")

def input_and_send():
    while 1:
        message = name+" : "+input(str("Please enter your message: "))
        conn.send(message.encode())
        print("Sent")
        print("")
import threading
background_thread = threading.Thread(target=input_and_send)
background_thread.daemon = True
background_thread.start()

for message in iter(lambda: conn.recv(1024).decode(), ''):
    print(s_name, ":", message)
    print("")

Answer 2

您是否尝试过使用线程模块或时间模块。这是因为两个脚本同时发送消息。尝试Ex（来自服务器端口的客户端等待消息，然后客户端向服务器发送消息）。

Answer 3

THIS IS SERVER

import socket
import threading as th

def accept_client():
    while True:
        # ACCEPTING    
        cli_sock, cli_add = ser_sock.accept()
        uname = cli_sock.recv(1024)
        CONN_LIST.append((uname, cli_sock))
        print('%s is now connected' %uname)

def broadcast_usr():
    while True:
        for i in range(len(CONN_LIST)):
            try:
                data = CONN_LIST[i][1].recv(1024)
                if data:
                    b_usr(CONN_LIST[i][1], CONN_LIST[i][0], data)
            except Exception as x:
                print(x.message)
                break

def b_usr(cs_sock, sen_name, msg):
    for i in range(len(CONNECTION_LIST)):
        if (CONN_LIST[i][1] != cs_sock):
            CONN_LIST[i][1].send(sen_name)
            CONN_LIST[i][1].send(msg)


if __name__ == "__main__":    
    CONN_LIST = []

    # SOCKET
    ser_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    # BINDING
    host = '192.168.x.x' #LOCAL HOST
    port = 4444
    ser_sock.bind((host, port))

    # LISTENING    
    ser_sock.listen(1)
    print('Chat server started on port : ' + str(port))

    thread_ac = th.Thread(target = accept_client)
    thread_ac.start()

    thread_bs = th.Thread(target = broadcast_usr)
    thread_bs.start()