Python client and server chat

Question

I am trying to implement a very basic client and server chat in Python though having some trouble, the response I get is that I can only run the client or the server not both at the same time so I can't chat.

Client code:

#client
import socket
import time
HOST = "localhost"
PORT = 5454
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind((HOST,PORT))
while True:
 data = raw_input("Enter..... ")
 s.sendto(data,(Host,PORT))
 print "Server says: " + s.recv(1024)
 if data=="bye" or s.recv(1024)=="bye":
 print "Exiting..........."
 time.sleep(1)
 break

Server code:

#server
import socket
import time
HOST = "localhost"
PORT = 5454
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind((HOST,PORT))
while True:
 print "Client says: " + s.recv(1024)
 data = raw_input("Enter..... ") 
 s.sendto(data,(HOST, PORT))
 if data=="bye" or s.recv(1024)=="bye":
 print "Exiting.................."
 time.sleep(1)
 break

Also does the PORT automatically close after the program closes or do I need to manually close the PORT somehow.

• ThinkChaos: On the client you side you don't want to bind, but connect. But that's not the only thing that's wrong here, have a look at the examples from the socket docs.

Answer 1

On This page there is example code for sockets, which you can easily adapt to your program.

In your script the first problem was:

s.bind((HOST,PORT))#for client

because, server binds to ip, not client, which will connect to the server using obviously function:

s.connect((HOST,PORT))

The other problem was that, your wasn't listening for new connection, and accepting them:

s.listen(1) #number defines amount of queued connection to server
conn, addr = s.accept()

The last mistake was sending data to client without even being sure, if client connected to server.

Hope I helped you with the problem. KubaBest