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Python socket client always sending message

So I have this server file which is ok, always is up for connections, after sending a message from the client, client connection closes. I want the client to be up again for sending a message (get input again). I don't want to start the client again (in my case it's odev1.py)
# server.py
import socket
HOST = socket.gethostname()
PORT = 65432
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server_socket:
server_socket.bind((HOST, PORT))
server_socket.listen()
while True:
print('waiting for a connection')
connection, client_address = server_socket.accept()
try:
print(f'{client_address[0]} has entered the chat\n')
while True:
data = connection.recv(1024)
print(f'{client_address[0]} - {str(data, encoding="utf-8")}')
if data:
print('sending data back to the client')
connection.sendall(data)
else:
print('no data from', client_address[0])
break
finally:
print("Closing current connection")
connection.close()
this is my client ->
# client.py
import sys
import socket
host = socket.gethostname()
port = 65432
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
except socket.error as e:
print("Error creating socket: %s" % e)
sys.exit(1)
# Second try-except block -- connect to given host/port
try:
s.connect((host, port))
except socket.gaierror as e:
print("Address-related error connecting to server: %s" % e)
sys.exit(1)
except socket.error as e:
print("Connection error: %s" % e)
sys.exit(1)
# Third try-except block -- sending data
try:
# NOTE: I want it to take input again
# Send data
message = input('write something: ')
s.sendall(message.encode('utf-8'))
print('sending {!r}'.format(message))
# Look for the response
amount_received = 0
amount_expected = len(message)
while amount_received < amount_expected:
data = s.recv(1024)
amount_received += len(data)
print('received {!r}'.format(data))
finally:
print('closing socket')
s.close()
this is how it looks right now:

Python sockets connecting but no data transfer

Just started learning python socket programming. I'm trying to send and receive data from a Raspberry Pi 3 using python sockets. I'm running the server program on the Raspberry Pi and the client program on my laptop running Ubuntu. Both are on the same WiFi network. The program runs and the client connects to the server, but there is no data transfer. Both the client and server do nothing. The two programs run properly if I try to run them both on the same device. Here's my code :-
Client
import socket
HOST = '172.16.31.51'
PORT = 5000
BUFSIZ = 1024
if __name__ == '__main__':
client_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = input("Enter hostname [%s]: " %HOST) or HOST
port = input("Enter port [%s]: " %PORT) or PORT
sock_addr = (host, int(port))
client_sock.connect(sock_addr)
payload = 'GET TIME'
try:
while True:
client_sock.send(payload.encode('utf-8'))
data = client_sock.recv(BUFSIZ)
print(repr(data))
more = input("Want to send more data to server[y/n]:")
if more.lower() == 'y':
payload = input("Enter payload: ")
else:
break
except KeyboardInterrupt:
print("Exited by user")
client_sock.close()
Server
import socket
from time import ctime
PORT = 5000
BUFSIZ = 1024
ADDR = ('', PORT)
if __name__ == '__main__':
server_socket = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
server_socket.bind(ADDR)
server_socket.listen(5)
server_socket.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR, 1)
while True:
print('Server waiting for connection...')
client_sock, addr = server_socket.accept()
print('Client connected from: ', addr)
while True:
data = client_sock.recv(BUFSIZ)
if not data or data.decode('utf-8') == 'END':
break
print("Received from client: %s" % data.decode('utf-8'))
print("Sending the server time to client: %s" %ctime())
try:
client_sock.send(bytes(ctime(), 'utf-8'))
except KeyboardInterrupt:
print("Exited by user")
client_sock.close()
server_socket.close()
EDIT:
The screenshots - https://imgur.com/a/NgzsC
As soon as I hit Ctrl + C, on the client side, the server seems to send some data before it disconnects from the client. Here's a screenshot of that - https://imgur.com/a/hoLwN

Your sockets work OK, but you made some other programming mistakes. Did you ever run it?
This is the modified working code.
(Hint: you can start testing just the client when you use nc -l 5000 as a simple manual server.
Client
import socket
HOST = '127.0.0.1'
PORT = 5000
BUFSIZ = 1024
if __name__ == '__main__':
client_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = str(raw_input("Enter hostname [%s]: " %HOST)) or HOST
port = str(raw_input("Enter port [%s]: " %PORT)) or PORT
sock_addr = (host, int(port))
client_sock.connect(sock_addr)
payload = 'GET TIME'
try:
while True:
client_sock.send(payload.encode('utf-8'))
data = client_sock.recv(BUFSIZ)
print(repr(data))
more = raw_input("Want to send more data to server[y/n]:")
if more.lower() == 'y':
payload = str(raw_input("Enter payload: "))
else:
break
except KeyboardInterrupt:
print("Exited by user")
client_sock.close()
Server
import socket
from time import ctime
PORT = 5004
BUFSIZ = 1024
ADDR = ('', PORT)
if __name__ == '__main__':
server_socket = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
server_socket.bind(ADDR)
server_socket.listen(5)
server_socket.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR, 1)
while True:
print('Server waiting for connection...')
client_sock, addr = server_socket.accept()
print('Client connected from: ', addr)
while True:
data = client_sock.recv(BUFSIZ)
if not data or data.decode('utf-8') == 'END':
break
print("Received from client: %s" % data.decode('utf-8'))
print("Sending the server time to client: %s" %ctime())
try:
client_sock.send( ctime().encode('utf-8') )
except KeyboardInterrupt:
print("Exited by user")
break;
client_sock.close()
server_socket.close()

socket is not listening for multiple request

Here is the code for server -
import socket, select,re
def getSocket( idd):
return CONNECTION_LIST[idd]
def broadcast_data (sock, message):
for socket in CONNECTION_LIST:
if socket != server_socket and socket != sock :
try :
socket.send(message)
except :
socket.close()
CONNECTION_LIST.remove(socket)
def single_client (sock , message , idd):
socket = getSocket ( idd )
if socket :
socket.send(message)
else:
print "chudap"
if __name__ == "__main__":
CONNECTION_LIST = []
RECV_BUFFER = 4096
PORT = 5000
PORTC = 2225
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind(("0.0.0.0", PORT))
server_socket.listen(10)
listen = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
listen.bind(("0.0.0.0" , PORTC))
#listen.listen(10)
CONNECTION_LIST.append(server_socket)
CONNECTION_LIST.append(listen)
print "Chat server started on port " + str(PORT)
idd = 1
while 1:
# Get the list sockets which are ready to be read through select
read_sockets,write_sockets,error_sockets = select.select(CONNECTION_LIST,[],[])
for sock in read_sockets:
if sock == server_socket:
sockfd, addr = server_socket.accept()
CONNECTION_LIST.append(sockfd)
#name = sockfd.recv(RECV_BUFFER)
print "connected from ip %s, id assigned is %d" % (addr[0] , idd)
broadcast_data(sockfd, "client with IP %s has entered with id = %d\n" % (addr[0] , idd))
idd += 1
elif sock == listen:
print "debugging"
data,addr = listen.recvfrom(RECV_BUFFER)
print "Received server probe request from [%s:%s]"%addr
listen.sendto("iam" , addr)#(addr[0] , 2624))
listen.close()
CONNECTION_LIST.remove(listen)
listen = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
listen.bind(("0.0.0.0" , PORTC))
CONNECTION_LIST.append(listen)
else:
try:
data = sock.recv(RECV_BUFFER)
if re.findall(r'.*/msg\d+' , data):
#print "got single client message request" + data
name = "private message from " + re.findall('([^:]+): /msg(\d+)([^"]+)' , data)[0][0] + ": "
#print name
eid = int(re.findall('([^:]+): /msg(\d+)([^"]+)' , data)[0][1])
#print eid
data = re.findall('([^:]+): /msg(\d+)([^"]+)' , data)[0][2]
#print data
data = name + data
#print "single client message sent with id = %d" %eid
single_client( sock , data , int(eid))
elif data:
broadcast_data(sock, data)
except:
broadcast_data(sock, "Client (%s, %s) is offline" % addr)
print "Client (%s, %s) is offline" % addr
sock.close()
CONNECTION_LIST.remove(sock)
continue
server_socket.close()
Here is the code for client -
import socket, select, string, sys
def prompt() :
sys.stdout.write('<You>: ')
sys.stdout.flush()
def exit(sock):
print "\n Thank you for using chat application\nBye"
sock.close()
sys.exit()
def printUsage():
print "1. By default your message will be sent to all clients sitting on the chat server"
print "2. You can send a private message to a person by starting your message as \"/msg{id}{Your message}\" for example /msg2Hi will send \"hi\" to client with id 2"
print "3. For quitting simply type \"/q\" or \"/quit\""
prompt()
PORTS = 2225
PORTC = 2624
if __name__ == "__main__":
broad = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
broad.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
broad.bind(( '0.0.0.0' , 2624) )
broad.sendto(b'whoisserver', 0, ("255.255.255.255", PORTS))
broad.settimeout(10)
print 15*"-" + "WELCOME TO CHATVILLE" + 15*"-" + "\nFinding the server"
try:
data , addr = broad.recvfrom(10)
except:
print "Can't find server ! Please ensure that server is up"
broad.close()
sys.exit()
broad.close()
if data <> "iam":
print "Can't find a valid server !"
sys.exit()
host = addr[0]
port = 5000
print addr
# host = sys.argv[1]
# port = int(sys.argv[2])
# print host,port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(2)
name = raw_input("Please Enter your name: ")
try :
s.connect((host, port))
s.send(name)
except :
print 'Unable to connect'
sys.exit()
print 'Connected to remote host. Enjoy...............................'
name = "<" + name + ">" + ": "
print " - type /h to see usage instructions any time :) - "
prompt()
while 1:
socket_list = [sys.stdin, s]
read_sockets, write_sockets, error_sockets = select.select(socket_list , [], [])
for sock in read_sockets:
if sock == s:
data = sock.recv(4096)
if not data :
print '\nDisconnected from chat server'
sys.exit()
else :
print ""
sys.stdout.write(data)
prompt()
else :
msg = sys.stdin.readline()
if str.startswith(msg, "/h") or str.startswith(msg,"/help"):
printUsage()
elif str.startswith(msg, "/quit") or str.startswith(msg,"/q"):
exit(s)
else:
msg = name + msg
s.send(msg)
prompt()
Main problem is that only one client is able to connect as soon as the first client connects are to server no other client is able to discover the server.
I tried by looking at the client's code by tcpdump and I can see the packet going at port number 2225, but the socket listen is not responding at all after the first connection.
PS - earlier I was not making instance of listen socket again and again but I tried this also and it didn't work out.

In the sever broadcast_data() does not exclude the UDP socket (listen) from the sockets to write to, and so it calls send() on that socket. This fails with exception
socket.error: [Errno 89] Destination address required
because no address is supplied (and can't be with socket.send()). The exception handler then closes the UDP socket and no further messages from new clients can be received. That's why additional clients can not connect to the server.
This is a perfect example of why it is not a good idea to use a bare except, i.e. an except statement that handles all exceptions. In this case the handler closes the UDP socket without even logging the fact. There are other instances of bare except statements in your code. I suggest that you handle specific exceptions to avoid this sort of bug. You can fix it by adding the UDP socket to the list of sockets to ignore:
def broadcast_data(sock, message):
for socket in CONNECTION_LIST:
if socket not in (server_socket, sock, listen):
try :
socket.send(message)
except socket.error as exc:
print '!!! An error occurred while writing to client. !!!'
print exc
socket.close()
CONNECTION_LIST.remove(socket)
Now no attempt will be made to send messages to the UDP listen socket, and the socket won't be closed due to error.
P.S. the code in your main loop that closes and reopens the listen socket is not necessary.

Add username input to python chat program

So I found this chat program on http://www.bogotobogo.com/python/python_network_programming_tcp_server_client_chat_server_chat_client_select.php
And I want to use this at my school for me and my friends, put I don't want to chat to be ex: [192.168.1.3] "Message". I want to be able to add another argument so it shows there name they input instead of Ip. It would be a little hard to have everyone using ips. Any suggestions?
Server Code:
# chat_server.py
import sys
import socket
import select
HOST = ''
SOCKET_LIST = []
RECV_BUFFER = 4096
PORT = 9009
def chat_server():
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((HOST, PORT))
server_socket.listen(10)
# add server socket object to the list of readable connections
SOCKET_LIST.append(server_socket)
print "Chat server started on port " + str(PORT)
while 1:
# get the list sockets which are ready to be read through select
# 4th arg, time_out = 0 : poll and never block
ready_to_read,ready_to_write,in_error = select.select(SOCKET_LIST,[],[],0)
for sock in ready_to_read:
# a new connection request recieved
if sock == server_socket:
sockfd, addr = server_socket.accept()
SOCKET_LIST.append(sockfd)
print "Client (%s, %s) connected" % addr
broadcast(server_socket, sockfd, "[%s:%s] entered our chatting room\n" % addr)
# a message from a client, not a new connection
else:
# process data recieved from client,
try:
# receiving data from the socket.
data = sock.recv(RECV_BUFFER)
if data:
# there is something in the socket
broadcast(server_socket, sock, "\r" + '[' + str(sock.getpeername()) + '] ' + data)
else:
# remove the socket that's broken
if sock in SOCKET_LIST:
SOCKET_LIST.remove(sock)
# at this stage, no data means probably the connection has been broken
broadcast(server_socket, sock, "Client (%s, %s) is offline\n" % addr)
# exception
except:
broadcast(server_socket, sock, "Client (%s, %s) is offline\n" % addr)
continue
server_socket.close()
# broadcast chat messages to all connected clients
def broadcast (server_socket, sock, message):
for socket in SOCKET_LIST:
# send the message only to peer
if socket != server_socket and socket != sock :
try :
socket.send(message)
except :
# broken socket connection
socket.close()
# broken socket, remove it
if socket in SOCKET_LIST:
SOCKET_LIST.remove(socket)
if __name__ == "__main__":
sys.exit(chat_server())
Client Code:
# chat_client.py
import sys
import socket
import select
def chat_client():
if(len(sys.argv) < 3) :
print 'Usage : python chat_client.py hostname port'
sys.exit()
host = sys.argv[1]
port = int(sys.argv[2])
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(2)
# connect to remote host
try :
s.connect((host, port))
except :
print 'Unable to connect'
sys.exit()
print 'Connected to remote host. You can start sending messages'
sys.stdout.write('[Me] '); sys.stdout.flush()
while 1:
socket_list = [sys.stdin, s]
# Get the list sockets which are readable
ready_to_read,ready_to_write,in_error = select.select(socket_list , [], [])
for sock in ready_to_read:
if sock == s:
# incoming message from remote server, s
data = sock.recv(4096)
if not data :
print '\nDisconnected from chat server'
sys.exit()
else :
#print data
sys.stdout.write(data)
sys.stdout.write('[Me] '); sys.stdout.flush()
else :
# user entered a message
msg = sys.stdin.readline()
s.send(msg)
sys.stdout.write('[Me] '); sys.stdout.flush()
if __name__ == "__main__":
sys.exit(chat_client())

Python socket server - continue to receive client data

How can I have a Python socket server tell me when there is a connection and then CONTINUE to give me back data that the client sends? When I do it, it connects and then just loops over, telling me it connected over and over again.
I,just want it to connect and then continually check (or grab) data sent to the server.
Also, how can I tell if the client disconnected?
address = ('', 7777)
server_socket = socket(AF_INET, SOCK_STREAM)
server_socket.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
try:
server_socket.bind(address)
except Exception, e:
print colored("Address already in use", 'red')
server_socket.listen(2)
print colored("Socket ready", 'blue')
while True:
client_socket, addr = server_socket.accept()
hostIP = addr[0]
port = addr[1]
try:
host = gethostbyaddr(hostIP)[0]
except:
host = hostIP
print colored("Got connection from: " + host, 'blue')
try:
recv_data = server_socket.recv(2048)
print("Got: " + recv_data)
except:
print "nothing"
recv_data = "" # this is because I test what it is later, but that's irrevlevant.
Thanks

You didn't do anything with client_socket; ie: the actual client connection. Furthermore, the server
cannot know how much the client wants to send and so it must CONTINUE (ie: in a
loop) to receive data. When the connection sends 'empty' data, the connection
is terminated and the server goes back to listening. If you want the server to
accept new connections and continue to receive data from existing connections
look up the threading module.
import socket
address = ('', 7777)
server_socket = socket.socket(AF_INET, SOCK_STREAM)
server_socket.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
try:
server_socket.bind(address)
except Exception, e:
print colored("Address already in use", 'red')
server_socket.listen(2)
print colored("Socket ready", 'blue')
while True:
client_socket, addr = server_socket.accept()
hostIP = addr[0]
port = addr[1]
try:
host = gethostbyaddr(hostIP)[0]
except:
host = hostIP
print colored("Got connection from: " + host, 'blue')
while True:
try:
recv_data = client_socket.recv(2048)
if not recv_data:
break
print("Got: " + recv_data)
except socket.error, e:
print "nothing"
recv_data = "" # this is because I test what it is later, but that's irrevlevant.