Socket programming in python

Standard
TCP/IP Server
 ---------------------------------------------------------------------------
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 , 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()
 
 
 
TCP/IP Client
---------------------------------------------------------------------------
[Receive Data]
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
 
 
 [Send Data]
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
 
#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'
 
 
 
 
 
UDP Server
 ---------------------------------------------------------------------------
import socket
import sys
 
HOST = ''   # Symbolic name meaning all available interfaces
PORT = 8888 # Arbitrary non-privileged port
 
# Datagram (udp) socket
try :
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    print 'Socket created'
except socket.error, msg :
    print 'Failed to create socket. Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
    sys.exit()
 
 
# Bind socket to local host and port
try:
    s.bind((HOST, PORT))
except socket.error , msg:
    print 'Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
    sys.exit()
     
print 'Socket bind complete'
 
#now keep talking with the client
while 1:
    # receive data from client (data, addr)
    d = s.recvfrom(1024)
    data = d[0]
    addr = d[1]
     
    if not data: 
        break
     
    reply = 'OK...' + data
     
    s.sendto(reply , addr)
    print 'Message[' + addr[0] + ':' + str(addr[1]) + '] - ' + data.strip()
     
s.close()
 
 
UDP Client
 ---------------------------------------------------------------------------
 
import socket   #for sockets
import sys  #for exit
 
# create dgram udp socket
try:
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
except socket.error:
    print 'Failed to create socket'
    sys.exit()
 
host = 'localhost';
port = 8888;
 
while(1) :
    msg = raw_input('Enter message to send : ')
     
    try :
        #Set the whole string
        s.sendto(msg, (host, port))
         
        # receive data from client (data, addr)
        d = s.recvfrom(1024)
        reply = d[0]
        addr = d[1]
         
        print 'Server reply : ' + reply
     
    except socket.error, msg:
        print 'Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
        sys.exit()
 
 
 
Reference :
TCP/IP => http://www.binarytides.com/python-socket-programming-tutorial/
UDP => http://www.binarytides.com/programming-udp-sockets-in-python/