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Is there a way to make 2 clients communicate in python?

So far I managed to get the server to communicate with multiple clients but I need to pass a value from one client to another.
Server code
import socket
from _thread import *
ServerSideSocket = socket.socket()
host = ''
port = 2004
ThreadCount = 0
try:
ServerSideSocket.bind((host, port))
except socket.error as e:
print(str(e))
print('Socket is listening..')
ServerSideSocket.listen(5)
def multi_threaded_client(connection):
connection.send(str.encode('Server is working:'))
while True:
data = connection.recv(2048)
response = data.decode('utf-8')
if not data:
break
connection.sendall(str.encode(response))
connection.close()
while True:
Client, address = ServerSideSocket.accept()
print('Connected to: ' + address[0] + ':' + str(address[1]))
start_new_thread(multi_threaded_client, (Client,))
ThreadCount += 1
print('Thread Number: ' + str(ThreadCount))
ServerSideSocket.close()
Client code
import socket
ClientMultiSocket = socket.socket()
host = '127.0.0.1'
port = 2004
print('Waiting for connection response')
try:
ClientMultiSocket.connect((host, port))
except socket.error as e:
print(str(e))
res = ClientMultiSocket.recv(1024)
while True:
Input = input('Hey there: ')
ClientMultiSocket.send(str.encode(Input))
res = ClientMultiSocket.recv(1024)
print(res.decode('utf-8'))
ClientMultiSocket.close()
I need the value from client1 to be passed to client2 and so forth, is there any way I can do that in python?

A TCP connection can only established to a socket which is a) bound to the specific address one is trying to connect to and b) is listening on this address for new connections which it then will c) accept to create a new socket which will then be used to communicate on this connection. Any communication outside such established connection is not possible in TCP.
The combination of a, b and c basically describes what a TCP server does. This also means that it is not possible to communicate between two TCP clients only which only called connect to each other. In order for a connect to succeed there must be something bound to the socket, listening to it and accepting connections on it (i.e. a, b and c - a TCP server).
A common way to implement the use cases of passing messages between different client (like in a chat server) is to send the message and intended client id to the server and let the server forward it to the intended client.

In a TCP connection, always, one is the server and the other are the client.
A simple use case:
client1 need to send a msg to client2, the pipeline could be:
client1 send a msg in JSON format to server "{'msg': 'abc',
'receiver':'client2'}"
server will store this info in a dict (or another structure you want)
client2 will ask for the server if there is any message to it
the server send the message stored to client2
It's more or less in this way that all the communications apps works.

conn.send('Hi'.encode()) BrokenPipeError: [Errno 32] Broken pipe (SOCKET)

hi i make model server client which works fine and i also create separate GUI which need to two input server IP and port it only check whether server is up or not. But when i run server and then run my GUI and enter server IP and port it display connected on GUI but on server side it throw this error. The Server Client working fine but integration of GUI with server throw below error on server side.
conn.send('Hi'.encode()) # send only takes string BrokenPipeError: [Errno 32] Broken pip
This is server Code:
from socket import *
# Importing all from thread
import threading
# Defining server address and port
host = 'localhost'
port = 52000
data = " "
# Creating socket object
sock = socket()
# Binding socket to a address. bind() takes tuple of host and port.
sock.bind((host, port))
# Listening at the address
sock.listen(5) # 5 denotes the number of clients can queue
def clientthread(conn):
# infinite loop so that function do not terminate and thread do not end.
while True:
# Sending message to connected client
conn.send('Hi'.encode('utf-8')) # send only takes string
data =conn.recv(1024)
print (data.decode())
while True:
# Accepting incoming connections
conn, addr = sock.accept()
# Creating new thread. Calling clientthread function for this function and passing conn as argument.
thread = threading.Thread(target=clientthread, args=(conn,))
thread.start()
conn.close()
sock.close()
This is part of Gui Code which cause problem:
def isOpen(self, ip, port):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
s.connect((ip, int(port)))
data=s.recv(1024)
if data== b'Hi':
print("connected")
return True
except:
print("not connected")
return False
def check_password(self):
self.isOpen('localhost', 52000)

Your problem is simple.
Your client connects to the server
The server is creating a new thread with an infinite loop
The server sends a simple message
The client receives the message
The client closes the connection by default (!!!), since you returned from its method (no more references)
The server tries to receive a message, then proceeds (Error lies here)
Since the connection has been closed by the client, the server cannot send nor receive the next message inside the loop, since it is infinite. That is the cause of the error! Also there is no error handling in case of closing the connection, nor a protocol for closing on each side.
If you need a function that checks whether the server is online or not, you should create a function, (but I'm sure a simple connect is enough), that works like a ping. Example:
Client function:
def isOpen(self, ip, port):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
s.connect((str(ip), int(port)))
s.send("ping".encode('utf-8'))
return s.recv(1024).decode('utf-8') == "pong" # return whether the response match or not
except:
return False # cant connect
Server function:
def clientthread(conn):
while True:
msg = conn.recv(1024).decode('utf-8') #receiving a message
if msg == "ping":
conn.send("pong".encode('utf-8')) # sending the response
conn.close() # closing the connection on both sides
break # since we only need to check whether the server is online, we break
From your previous questions I can tell you have some problems understanding how TCP socket communication works. Please take a moment and read a few articles about how to communicate through sockets. If you don't need live communications (continous data stream, like a video, game server, etc), only login forms for example, please stick with well-known protocols, like HTTP. Creating your own reliable protocol might be a little complicated if you just got into socket programming.
You could use flask for an HTTP back-end.

How to make a TCP server handle multiple clients?

I'm trying to make a Python server where multiple clients can connect but I've run into a problem I tried everything that I found on the internet.
I'm running a laptop whit windows 7 and an I3 processor.
This is the file called tcp:
import socket
def make_server (ip,port):
try:
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((ip, port))
server.listen(1)
return server
except Exception as ex:
print(ex)
return None
def accept(server):
conn, addr = server.accept()
return conn
def make_client():
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
return client
def client_connect(client,ip,port):
client.connect((ip,port))
def sendall(conn,mess):
conn.send(str(mess).encode("utf-8"))
def rec(conn,rate):
mess = conn.recv(rate).decode("utf-8")
return mess
def close(client):
client.close()
This is the server:
from multiprocessing import Process
from random import randint
import tcp
import sys
def start(sip, sport):
print("Making sob server...")
print("id= {}".format(sport))
sserver = tcp.make_server(sip, sport)
print("Sub Server Started!")
sconn = tcp.accept(sserver)
tcp.sendall(sconn, "connected!!")
while True:
try:
tcp.sendall(sconn, randint(0, 100))
except Exception as ex:
print("")
print("From server {} error:".format(port))
print(ex)
print("")
break
ip = "192.168.0.102"
port = 8000
subport = 9000
server = tcp.make_server(ip, port)
if server is None:
sys.exit(0)
print("Started!")
while True:
print("Wating for new connection!")
con = tcp.accept(server)
print("Connected!")
subport = subport + 1
tcp.sendall(con, subport)
print("New Port Sent!")
print("New Port = {}".format(subport))
subs = Process(target=start, args=(ip, subport))
subs.start()
subs.join()
This is the client:
import tcp
import time
nport = 0
ip = "192.168.0.102"
port = 8000
client = tcp.make_client()
tcp.client_connect(client,ip,port)
nport = tcp.rec(client,1024)
print(nport)
tcp.close(client)
nport = int(nport)
time.sleep(1)
print(nport)
client = tcp.make_client()
tcp.client_connect(client,ip,nport)
while True:
mess = tcp.rec(client, 1024)
if(mess):
print(mess)
The error is:
[WinError 10048]Only one usage of each socket address (protocol/network address/port) is normally permitted Python
Feel free to change anything you want.
If you need any info in plus just ask.

You are creating a socket in the client with tcp.make_client. You are then using that socket to connect to the server via tcp.client_connect. Presumably you successfully receive the new port number back from the server. But then you are trying to re-use the same socket to connect to those ports.
This is the proximate cause of your error: A socket can only be used for a single TCP connection. If you want to create a new connection, you must first create a new socket.
That being said, if you are simply trying to create a server that will accept multiple connections, you're making it way too complicated. The server can receive any number of connections on its single listening port, as long as a different address/port combination is used by each client.
One way to structure this in a server is something like this:
# Create and bind listening socket
lsock = socket.socket()
lsock.bind(('', port))
lsock.listen(1)
while True:
csock, addr = lsock.accept()
print("Got connection from {}".format(addr))
# Start sub-process passing it the newly accepted socket as argument
subs = Process(target=start, args=(csock, ))
subs.start()
# Close our handle to the new socket (it will remain open in the
# sub-process which will use it to talk to the client)
csock.close()
# NOTE: do not call subs.join here unless you want the parent to *block*
# waiting for the sub-process to finish (and if so, what is the point in
# creating a sub-process?)
There are several others ways to do it as well: you can create multiple threads to handle multiple connections, or you can handle all connections in a single thread by using select or with asynchronous I/O.
The client is typically much simpler -- as it usually only cares about its own one connection -- and doesn't care which way the server is implemented:
sock = socket.socket()
sock.connect((ip, port))
while True:
sock.send(...)
sock.recv(...)
If the client does wish to connect to the same server again, it simply creates a second socket and call its connect method with the same server IP and port.
Usually, the client never needs to specify its own port, only the server's port. It simply calls connect and the client-side operating system chooses an unused port for it. So the first time, the client creates a socket and connects it (to the server's listening port), the client-side OS may choose port 50001. The next time it creates and connects a socket, it may get 50002 and so on. (The exact port numbers chosen depend on the operating system implementation and other factors, such as what other programs are running and creating connections.)
So, given client IP 192.168.0.101 and server IP 192.168.0.102, and assuming the server is listening on port 8000, this would result in these two connections:
(192.168.0.101/50001) ====> (192.168.0.102/8000)
(192.168.0.101/50002) ====> (192.168.0.102/8000)

Communicating with multiple clients using one TCP socket python

I am using TCP sockets to communicate between my server and clients. The server code and socket code are as below:
server:
from socket import *
HOST = 'xx.xx.xx.xx'
PORT = 1999
serversocket = socket(AF_INET,SOCK_STREAM)
serversocket.bind((HOST,PORT))
print 'bind success'
serversocket.listen(5)
print 'listening'
while True:
(clientsocket, address) = serversocket.accept()
print ("Got client request from",address)
#clientsocket.send('True')
data = clientsocket.recv(1024)
print data
clientsocket.send('True')
clientsocket.close()
client:
import socket
import sys
# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Connect the socket to the port on the server given by the caller
server_address = ('xx.xx.xx.xx', 1999)
print >>sys.stderr, 'connecting to %s port %s' % server_address
sock.connect(server_address)
try:
message = 'This is the message. It will be repeated.'
print >>sys.stderr, 'sending'
for x in range (0,1):
name=raw_input ('what is ur name')
print type(name)
sock.send(name)
print sock.recv(1024)
finally:
sock.close()
I am able to communicate with the server from client and able to send and receive data. But the problem I am facing is that I am not able to send and receive data continuously from the server. I have to restart my client code on my laptop to send and receive data again from the server. The way the above client code is working is that when I give a keyboard input, then the socket sends data to server and server responds back. But in the client code, in the for loop if I do two iterations, for the second iteration the data I enter from keyboard is not reaching server. I need to restart my client code to send data again. How do I fix this ?
Also, when once client is connected to the server, the other cannot connect to the server. Any ideas on how to do this ?

You need to design and implement a protocol that specifies what each side is supposed to do and then implement that protocol. You're expecting it to work by magic.
For example:
data = clientsocket.recv(1024)
I suspect you are expecting this to receive a "message". But TCP has no notion of messages. If you need to send and receive messages, you need to define precisely what a "message" is for your protocol and write code to send and receive them.
It may be helpful to look at the specifications for other protocols that use TCP such as HTTP, FTP, or IRC. It really is worth the time to write out a specification of your protocol before you write any code. It will save a lot of pain.

Receiving 'Request String' in Python

I'm building a game-server in Python. The functionality is pretty well-defined. The server will listen on the port 6000 and a remote client will send a request. Then the server will establish a connection to the client's port 7000. From then on, the client will keep sending 'requests' (basically, strings such as "UP#", "DOWN#", "SHOOT#" etc.) to server's port 6000.
This is the problem. I have made a 'server' who listens on the port 6000. This means I cannot bind a client to the same port. Is there a way that I can get the data string of an incoming request in a server? So far, I only have this.
What am I doing wrong here? Any workarounds for this issue? In short, can I read the incoming request string from a client in the server code?
Thanks in advance.
def receive_data(self):
errorOccured = False
connection = None
try:
listener = socket.socket() # Create a socket object.
host = socket.gethostname()
port = 6000 # The port that the server keeps listening to.
listener.bind(('', port))
# Start listening
listener.listen(5)
statement = ("I:P0:7,6;8,1;0,4;3,8;3,2;1,6:5,4;9,3;8,7;2,6;1,4;2,7;6,1;6,3:2,1;8,3;5,8;9,8;7,2;0,3;9,4;4,8;7,1;6,8#\n","S:P0;0,0;0#","G:P0;0,0;0;0;100;0;0:4,3,0;5,4,0;3,8,0;2,7,0;6,1,0;5,8,0;1,4,0;1,6,0#", "C:0,5:51224:824#","G:P0;0,0;0;0;100;0;0:4,3,0;5,4,0;3,8,0;2,7,0;6,1,0;5,8,0;1,4,0;1,6,0#","G:P0;0,1;2;0;100;0;0:4,3,0;5,4,0;3,8,0;2,7,0;6,1,0;5,8,0;1,4,0;1,6,0#")
# This is just game specific test data
while True:
c, sockadd = listener.accept() # Establish connection with client.
print 'incoming connection, established with ', sockadd
i = 0 # Just a counter.
while i<len(statement):
try:
self.write_data(statement[i], sockadd[0])
time.sleep(1) # The game sends updates every second to the clients
i = i + 1
#print listener.recv(1024) -- this line doesn't work. gives an error
except:
print "Error binding client"
c.close() # Close the connection
return
except:
print "Error Occurred"

I'm going to answer it because I got some help and figured it out.
The most basic thing I can do is to use the client connection which is c for this purpose. In here, instead of the commented line data=listener.recv(1024) I should have used data= c.recv(1024). Now it works.
Another way is to use SocketServers with a StreamingRequestHandler. While this is ideal for usage of typical servers, if a lot of objects are involved it could reduce the flexibility.