Notes

import socket
import select
from _thread import *
import sys


server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
"""
the first argument AF_INET is the address domain of the socket. This is used when we have an Internet Domain
with any two hosts
The second argument is the type of socket. SOCK_STREAM means that data or characters are read in a continuous flow
"""
if len(sys.argv) != 3:
print ("Correct usage: script, IP address, port number")
exit()
IP_address = str(sys.argv[1])
Port = int(sys.argv[2])
server.bind((IP_address, Port))
#binds the server to an entered IP address and at the specified port number. The client must be aware of these parameters
server.listen(100)
#listens for 100 active connections. This number can be increased as per convenience
list_of_clients=[]

def clientthread(conn, addr):
sentence = ("Welcome to this chatroom!")
conn.send(sentence.encode('utf-8'))
#sends a message to the client whose user object is conn
while True:
try:
message = conn.recv(2048).decode('utf-8')
if message:
print ("<" + addr[0] + "> " + message)
message_to_send = "<" + addr[0] + "> " + message
broadcast(message_to_send,conn)
#prints the message and address of the user who just sent the message on the server terminal
else:
remove(conn)
except:
continue

def broadcast(message,connection):
for clients in list_of_clients:
if clients!=connection:
try:
clients.send(message)
except:
clients.close()
remove(clients)

def remove(connection):
if connection in list_of_clients:
list_of_clients.remove(connection)

while True:
conn, addr = server.accept()
"""
Accepts a connection request and stores two parameters, conn which is a socket object for that user, and addr which contains
the IP address of the client that just connected
"""
list_of_clients.append(conn)
print (addr[0] + " connected")
#maintains a list of clients for ease of broadcasting a message to all available people in the chatroom
#Prints the address of the person who just connected
start_new_thread(clientthread,(conn,addr))
#creates and individual thread for every user that connects

conn.close()
server.close()