python tcp socket client / server examples

bind_socket.py

#!/usr/bin/python

import socket	#for sockets
import sys	#for exit

try:
	#create an AF_INET, STREAM socket (TCP)
	s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
except socket.error, msg:
	print 'Failed to create socket. Error code: ' + str(msg[0]) + ' , Error message : ' + msg[1]
	sys.exit();

print 'Socket Created'

host = 'www.google.com'
port = 80

try:
	remote_ip = socket.gethostbyname( host )

except socket.gaierror:
	#could not resolve
	print 'Hostname could not be resolved. Exiting'
	sys.exit()
	
print 'Ip address of ' + host + ' is ' + remote_ip

#Connect to remote server
s.connect((remote_ip , port))

print 'Socket Connected to ' + host + ' on ip ' + remote_ip

socket_client.py

#!/usr/bin/python

#Socket client example in python

import socket	#for sockets
import sys	#for exit

#create an INET, STREAMing socket
try:
	s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
except socket.error:
	print 'Failed to create socket'
	sys.exit()
	
print 'Socket Created'

host = 'www.google.com';
port = 80;

try:
	remote_ip = socket.gethostbyname( host )

except socket.gaierror:
	#could not resolve
	print 'Hostname could not be resolved. Exiting'
	sys.exit()

#Connect to remote server
s.connect((remote_ip , port))

print 'Socket Connected to ' + host + ' on ip ' + remote_ip

#Send some data to remote server
message = "GET / HTTP/1.1\r\n\r\n"

try :
	#Set the whole string
	s.sendall(message)
except socket.error:
	#Send failed
	print 'Send failed'
	sys.exit()

print 'Message send successfully'

#Now receive data
reply = s.recv(4096)

print reply

socket_server.py

#!/usr/bin/python
# credits: http://www.binarytides.com/python-socket-server-code-example/

'''
	Simple socket server using threads
'''

import socket
import sys

HOST = ''	# Symbolic name, meaning all available interfaces
PORT = 8888	# Arbitrary non-privileged port

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Socket created'

#Bind socket to local host and port
try:
	s.bind((HOST, PORT))
except socket.error as msg:
	print 'Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
	sys.exit()
	
print 'Socket bind complete'

#Start listening on socket
s.listen(10)
print 'Socket now listening'

#now keep talking with the client
while 1:
    #wait to accept a connection - blocking call
	conn, addr = s.accept()
	print 'Connected with ' + addr[0] + ':' + str(addr[1])
	
s.close()

socket_server_threads.py

#!/usr/bin/python
# credits: http://www.binarytides.com/python-socket-server-code-example/

'''
	Simple socket server using threads
'''

import socket
import sys
from thread import *

HOST = ''	# Symbolic name meaning all available interfaces
PORT = 8888	# Arbitrary non-privileged port

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Socket created'

#Bind socket to local host and port
try:
	s.bind((HOST, PORT))
except socket.error as msg:
	print 'Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
	sys.exit()
	
print 'Socket bind complete'

#Start listening on socket
s.listen(10)
print 'Socket now listening'

#Function for handling connections. This will be used to create threads
def clientthread(conn):
	#Sending message to connected client
	conn.send('Welcome to the server. Type something and hit enter\n') #send only takes string
	
	#infinite loop so that function do not terminate and thread do not end.
	while True:
		
		#Receiving from client
		data = conn.recv(1024)
		reply = 'OK...' + data
		if not data: 
			break
	
		conn.sendall(reply)
	
	#came out of loop
	conn.close()

#now keep talking with the client
while 1:
    #wait to accept a connection - blocking call
	conn, addr = s.accept()
	print 'Connected with ' + addr[0] + ':' + str(addr[1])
	
	#start new thread takes 1st argument as a function name to be run, second is the tuple of arguments to the function.
	start_new_thread(clientthread ,(conn,))

s.close()

socket_server_with_select.py

#!/usr/bin/python
# Socket server in python using select function
# credits: http://www.binarytides.com/python-socket-server-code-example/

import socket, select
 
if __name__ == "__main__":
     
	CONNECTION_LIST = []	# list of socket clients
	RECV_BUFFER = 4096 # Advisable to keep it as an exponent of 2
	PORT = 5000
		
	server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
	# this has no effect, why ?
	server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
	server_socket.bind(("0.0.0.0", PORT))
	server_socket.listen(10)

	# Add server socket to the list of readable connections
	CONNECTION_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
		read_sockets,write_sockets,error_sockets = select.select(CONNECTION_LIST,[],[])

		for sock in read_sockets:
			
			#New connection
			if sock == server_socket:
				# Handle the case in which there is a new connection recieved through server_socket
				sockfd, addr = server_socket.accept()
				CONNECTION_LIST.append(sockfd)
				print "Client (%s, %s) connected" % addr
				
			#Some incoming message from a client
			else:
				# Data recieved from client, process it
				try:
					#In Windows, sometimes when a TCP program closes abruptly,
					# a "Connection reset by peer" exception will be thrown
					data = sock.recv(RECV_BUFFER)
					# echo back the client message
					if data:
						sock.send('OK ... ' + data)
				
				# client disconnected, so remove from socket list
				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()