Programming with Sockets

Let's try to connect a client socket to a server process. The following code is an
example of TCP client socket that makes a connection to server socket:

import socket

import sys

if __name__ == '__main__':

try:

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

except socket.error as err:

print("Failed to crate a socket")

print("Reason: %s" %str(err))

sys.exit();

print('Socket created')

target_host = input("Enter the target host name to connect: ")

target_port = input("Enter the target port: ")

try:

sock.connect((target_host, int(target_port)))

print("Socket Connected to %s on port: %s" %(target_host,

target_port))

sock.shutdown(2)

except socket.error as err:

print("Failed to connect to %s on port %s" %(target_host,

target_port))

print("Reason: %s" %str(err))

sys.exit();

If you run the preceding TCP client, an output similar to the following will be shown:

python 7_1_tcp_client_socket.py

Socket created

Enter the target host name to connect: 'www.python.org'

Enter the target port: 80

Socket Connected to http://www.python.org on port: 80

However, if socket creation has failed for some reason, such as invalid DNS,
an output similar to the following will be shown:

python 7_1_tcp_client_socket.py

Socket created