How to Build a Chat Application Using Python Sockets

Building a chat application using Python sockets is a great way to understand networking concepts and socket programming. In this tutorial, we will create a simple chat app using Python’s built-in socket module.

What is Socket Programming?

Sockets allow communication between two nodes on a network. A server listens for incoming connections, while clients connect to the server to exchange messages.

Setting Up the Server

First, let’s create the server-side script that listens for client connections and facilitates communication.

    import socket

    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server_socket.bind(('0.0.0.0', 12345))
    server_socket.listen(5)
    print("Server started. Waiting for connections...")

    client_socket, addr = server_socket.accept()
    print(f"Connection established with {addr}")

    while True:
        message = client_socket.recv(1024).decode()
        if message.lower() == 'exit':
            break
        print("Client:", message)
        response = input("You: ")
        client_socket.send(response.encode())

    client_socket.close()
    server_socket.close()
	

Creating the Client

Now, let’s write the client-side script that connects to the server.

    import socket

    client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    client_socket.connect(('127.0.0.1', 12345))
    print("Connected to server.")

    while True:
        message = input("You: ")
        client_socket.send(message.encode())
        if message.lower() == 'exit':
            break
        response = client_socket.recv(1024).decode()
        print("Server:", response)

    client_socket.close()
	

Running the Chat Application

Follow these steps to run the chat app:

1. Run the server script first: python server.py
2. Run the client script in a separate terminal or another machine: python client.py
3. Start chatting! Type messages and press enter to send.
4. Type exit to close the connection.

Conclusion

Congratulations! You’ve built a simple chat application using Python sockets. You can expand it by adding encryption, a GUI, or multi-client support.