This gist containts two files a server and a client. The server echos back what is sent by the client. This is done by using socket programming in python

echo_client.py

#!/usr/bin/env python3
# Library needed for socket programming
import socket

# Defining the header size
HEADER = 64
# Defining a port for the client to connect to
PORT = 5050
# Format specification of the message
FORMAT = "utf-8"
# A string to disconnect from the server
DISCONNECT_MESSAGE = "DISCONNECTED"
# Getting th IP address of the system
SERVER = socket.gethostbyname(socket.gethostname())
# Attaching the port and IP address together like 192.168.15.5 and 5050
ADDR = (SERVER, PORT)

# Creating a socket object with IPV4 protocol (AF_INET) and tcp agent (SOCK_STREAM)
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Connecting client to server
client.connect(ADDR)


def send_msg(msg):
    # Encoding the message in specified format
    message = msg.encode(FORMAT)
    msg_length = len(message)
    # Converting length of message to correct format
    send_length = str(msg_length).encode(FORMAT)
    # Attaching length of message to the header (the space betweeen the quotes is must)
    send_length += b" " * (HEADER - len(send_length))
    # Sending legth of message
    client.send(send_length)
    # Sending message
    client.send(message)
    # Printing if the message was recieved/ack
    print(client.recv(2048).decode(FORMAT))


def main():
    while True:
        msgs = input("Enter a message to be sent to the server: ")
        send_msg(msgs)
        choice = input("Do you want to continue [y/n]: ")
        if choice.lower() == "n":
            break
    send_msg(DISCONNECT_MESSAGE)
    client.close()


if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        print("\n\nClosing Client\n")

echo_server.py

#!/usr/bin/env python3

# Library needed for socket programming
import socket

# Library needed for multiple messages at the same time so multiple clients can use the same server
import threading

# Defining the header size
HEADER = 64
# Defining a port for the client to connect to
PORT = 5050
# Format specification of the message
FORMAT = "utf-8"
# A string to disconnect from the server
DISCONNECT_MESSAGE = "DISCONNECTED"
# Getting th IP address of the system
SERVER = socket.gethostbyname(socket.gethostname())
# Attaching the port and IP address together like 192.168.15.5 and 5050
ADDR = (SERVER, PORT)

# Creating a socket object with IPV4 protocol (AF_INET) and tcp agent (SOCK_STREAM)
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Connecting server to the port and locking it.
server.bind(ADDR)


def handle_client(conn, addr):
    print(f"[NEW CONNECTION] {addr} connected")
    connected = True
    while connected:
        # Get message length
        msg_length = conn.recv(HEADER).decode(FORMAT)
        if msg_length:
            msg_length = int(msg_length)
            # Get message
            msg = conn.recv(msg_length).decode(FORMAT)
            # If message is equal to disconnect message break
            if msg == DISCONNECT_MESSAGE:
                connected = False

            # Print message
            print(f"[{addr}] {msg}")
            # Send ack
            conn.send("MESSAGE RECEIVED".encode(FORMAT))
    # Close connection with client
    conn.close()


def start():
    print(f"[LISTENING] Server is active on {SERVER}")
    # Listening on the port and ip
    server.listen()
    while True:
        conn, addr = server.accept()
        thread = threading.Thread(target=handle_client, args=(conn, addr))
        # Starting a new thread for a new client
        thread.start()
        print(f"[ACTIVE CONNECTIONS] {threading.activeCount() - 1}")


if __name__ == "__main__":
    try:
        print("[STARTING] server is starting")
        start()
    except KeyboardInterrupt:
        print("\n\nClosing server\n")