tcp.server.py.ipynb

Kernel: Python 3

Networking in Python

• Networking in any programming language is needed to send messages over different across networks.

• Sockets and Socket APIs are used to send messages across network and they function as IPC(inter-process-Communication).

• Sockets are created using a set of programming request called socket API (Application Programming Interface).

• Sockets are the communcation gateway between server & client.

Steps :

1. Define Socket(TCP,UDP etc) (g = socket.socket (socket_family, type_of_socket, protocol=value))

2. Write methods to manage connections form server to client & vice versa.

Common Server Socket Methods

• listen(): is used to establish and start TCP listener.

• bind(): is used to bind address (host-name, port number) to the socket.

• accept(): is used to TCP client connection until the connection arrives.

• connect(): is used to initiate TCP server connection.

• send(): is used to send TCP messages.

• recv(): is used to receive TCP messages.

• recvfrom():is used to send UDP messages

• sendto(): is used to send UDP messages

• close(): is used to close a socket.

Code to Setup Socket virtually(UDP Socket)

from socket import *

# use socket.socket() - function

udp_1=socket.socket(socket.AF_INET, socket.SOCK_DGRAM) ## for UDP
## tcp_2=tcp1=socket.socket(socket.AF_INET, socket.SOCK_STREAM)### for TCP

## Program for Network Connection.

import socket
import sys
 
# Create a TCP/IP socket
stream_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 
# Define host
host = 'localhost'
 
# define the communication port
port = 8080
 
# Connect the socket to the port where the server is listening
server_address = ((host, port))
 
print ("connecting")
 
stream_socket.connect(server_address)
 
 
# Send data
message = 'message'
stream_socket.sendall(message)
 
# response
data = stream_socket.recv(10)
print (data)
 
 
print ('socket closed')

### Save the file with filename - tcpserver.py ,This will open a web server at port 60.

conda -c install socket

pip install socket

import socket

serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = "localhost"
port = 8000
print (host)
print (port)
serversocket.bind((host, port))
serversocket.listen(20)
print ('server started and listening')
while 1:
    (clientsocket, address) = serversocket.accept()
    print ("connection found!")
    data = clientsocket.recv(1024).decode()
    print (data)
    r='REceieve'
    clientsocket.send(r.encode())