Python Websockets without asyncio: A Comprehensive Guide

Introduction

Websockets are a popular protocol for real-time communication between client and server. It allows bidirectional communication over a single TCP connection, which makes it ideal for applications that require real-time updates. Python provides various libraries for implementing websockets, but most of them rely on asyncio, which can be a bit complex and overwhelming for beginners. In this article, we will explore how to implement websockets in Python without asyncio.

What are Websockets?

Websockets are a protocol that allows for real-time, bidirectional communication between client and server. Unlike traditional HTTP requests, which are unidirectional, websockets allow both the client and server to send and receive data over a single TCP connection. This makes it ideal for applications that require real-time updates, such as chat applications, online gaming, and stock tickers.

Websockets use a handshake process to establish a connection between the client and server. Once the connection is established, data can be sent in either direction at any time, without the need for an HTTP request/response cycle. This makes websockets more efficient than traditional HTTP requests, as they eliminate the need for repeated handshakes and headers.

Why Use Python for Websockets?

Python is a popular programming language for web development, and it provides several libraries for implementing websockets. Python’s ease of use and readability make it an attractive choice for beginners, while its powerful features and large community make it a robust choice for experienced developers.

Python also provides several frameworks for web development, such as Django and Flask, which can be used in conjunction with websockets. This makes it easy to build complex web applications that require real-time updates.

Implementing Websockets without asyncio

Most Python libraries for websockets, such as aiohttp and websockets, rely on asyncio for their implementation. While asyncio provides a powerful and efficient way to handle asynchronous I/O, it can be a bit complex and overwhelming for beginners.

Fortunately, there are several libraries that provide a simpler way to implement websockets in Python, without relying on asyncio. In this section, we will explore some of these libraries.

WebSocket-Server

WebSocket-Server is a simple and lightweight library for implementing websockets in Python. It provides a simple API for creating a websocket server, handling incoming connections, and sending and receiving data over the websocket connection.

To use WebSocket-Server, you first need to install it using pip:

pip install websocket-server

Once installed, you can create a websocket server using the following code:

1. import websocket_server

2. def new_client(client, server):

1. print(“New client connected and was given id %d” % client[‘id’])

2. server.send_message_to_all(“Hey all, a new client has joined us”)

3. def message_received(client, server, message):

1. print(“Client(%d) said: %s” % (client[‘id’], message))

2. server.send_message_to_all(“Client(%d) said: %s” % (client[‘id’], message))

4. server = websocket_server.WebSocketServer(8080, host=’localhost’)

5. server.set_fn_new_client(new_client)

6. server.set_fn_message_received(message_received)

7. server.run_forever()

The above code creates a websocket server that listens on port 8080 of the localhost. When a new client connects to the server, the new_client function is called, which sends a message to all connected clients. When a client sends a message to the server, the message_received function is called, which sends the message to all connected clients.

Simple-WebSocket-Server

Simple-WebSocket-Server is another simple library for implementing websockets in Python. It provides a simple API for creating a websocket server, handling incoming connections, and sending and receiving data over the websocket connection.

To use Simple-WebSocket-Server, you first need to install it using pip:

pip install simple-websocket-server

Once installed, you can create a websocket server using the following code:

1. import websocket_server

2. class SimpleEcho(WebSocket):

1. def handleMessage(self):

1. message = self.data

2. self.sendMessage(message)

3. server = SimpleWebSocketServer(”, 8000, SimpleEcho)

4. server.serveforever()

The above code creates a websocket server that listens on port 8000 of the localhost. When a client sends a message to the server, the handleMessage function is called, which sends the message back to the client.

Conclusion

Websockets are a powerful protocol for real-time communication between client and server. Python provides several libraries for implementing websockets, but most of them rely on asyncio, which can be complex and overwhelming for beginners. Fortunately, there are several libraries that provide a simpler way to implement websockets in Python, without relying on asyncio.

WebSocket-Server and Simple-WebSocket-Server are two such libraries that provide a simple and lightweight way to implement websockets in Python. By using these libraries, you can easily build real-time applications that require bidirectional communication between client and server.

FAQ

What are websockets?

Websockets are a protocol that allows for real-time, bidirectional communication between client and server.

Why use Python for websockets?

Python is a popular programming language for web development, and it provides several libraries for implementing websockets.

What are some libraries for implementing websockets in Python?

Some popular libraries for implementing websockets in Python include aiohttp, websockets, WebSocket-Server, and Simple-WebSocket-Server.

What is asyncio?

Asyncio is a Python library for writing concurrent code using the async/await syntax. It is commonly used in conjunction with websockets to handle asynchronous I/O.