Everything You Need to Know About Websocket Library Python

Websockets are an advanced technology that allows full duplex communication between the client and the server. With websockets, you can create real-time chat applications, multiplayer games, and much more. Python, being one of the most popular programming languages, has a variety of websocket libraries available. In this article, we will explore the best websocket library Python has to offer and how to use it.

Table of Contents show

What is a Websocket?

A websocket is a communication protocol that allows two-way communication between the client and the server. Unlike HTTP, which is a request-response protocol, websockets allow real-time, event-driven communication. This means that the server can send data to the client without the client having to request it. In addition, the client can also send data to the server without the need for a new HTTP request.

What is a Websocket Library?

A websocket library is a set of functions and classes that enable you to implement websockets in your Python application. There are several websocket libraries available for Python, each with their own strengths and weaknesses. Some of the most popular libraries are:

AutobahnPython
WebSocket-Client
WebSockets
Tornado
Python-SocketIO

Why Use a Websocket Library?

Using a websocket library can greatly simplify the process of implementing websockets in your application. Rather than having to write all of the code yourself, you can simply use the functions and classes provided by the library. This can save you time and reduce the likelihood of errors. In addition, many websocket libraries include features such as error handling, message parsing, and automatic reconnection, which can further simplify the development process.

The Best Websocket Library for Python: AutobahnPython

AutobahnPython is widely regarded as the best websocket library for Python. It is a mature library that has been in development since 2010 and is currently maintained by the Crossbar.io team. AutobahnPython is compatible with both Python 2 and Python 3 and supports both client and server implementations.

Installation

Installing AutobahnPython is easy using pip:

pip install autobahn

Creating a WebSocket Server with AutobahnPython

Creating a websocket server with AutobahnPython is straightforward. Here is a basic example:

from autobahn.twisted.websocket import WebSocketServerProtocol, WebSocketServerFactoryfrom twisted.internet import reactorclass MyServerProtocol(WebSocketServerProtocol):
def onConnect(self, request):print("Client connected: {}".format(request.peer))
def onOpen(self):print("WebSocket connection open.")
def onMessage(self, payload, isBinary):if isBinary:print("Binary message received: {} bytes".format(len(payload)))else:print("Text message received: {}".format(payload.decode('utf8')))
def onClose(self, wasClean, code, reason):print("WebSocket connection closed: {}".format(reason))
if __name__ == '__main__':factory = WebSocketServerFactory()factory.protocol = MyServerProtocol
reactor.listenTCP(9000, factory)reactor.run()

This example creates a websocket server that listens on port 9000. When a client connects, the onConnect method is called, and when the connection is opened, the onOpen method is called. When a message is received, the onMessage method is called, and when the connection is closed, the onClose method is called.

Creating a WebSocket Client with AutobahnPython

Creating a websocket client with AutobahnPython is just as easy. Here is a basic example:

from autobahn.twisted.websocket import WebSocketClientProtocol, WebSocketClientFactoryfrom twisted.internet import reactorclass MyClientProtocol(WebSocketClientProtocol):
def onConnect(self, response):print("Server connected: {}".format(response.peer))
def onOpen(self):print("WebSocket connection open.")self.sendMessage("Hello, world!".encode('utf8'))
def onMessage(self, payload, isBinary):if isBinary:print("Binary message received: {} bytes".format(len(payload)))else:print("Text message received: {}".format(payload.decode('utf8')))
def onClose(self, wasClean, code, reason):print("WebSocket connection closed: {}".format(reason))
if __name__ == '__main__':factory = WebSocketClientFactory()factory.protocol = MyClientProtocol
reactor.connectTCP("localhost", 9000, factory)reactor.run()

This example creates a websocket client that connects to a server running on localhost:9000. When the connection is opened, the client sends a message to the server, and when a message is received, the onMessage method is called.

Frequently Asked Questions

What is the difference between HTTP and websockets?

HTTP is a request-response protocol, which means that the client sends a request to the server, and the server responds with a message. Websockets, on the other hand, allow bidirectional communication between the client and the server, which means that either party can send messages at any time.

What are some use cases for websockets?

Websockets are commonly used for real-time applications such as chat applications, multiplayer games, and stock tickers. They can also be used for any application that requires real-time updates or notifications.

Can websockets be used with Python?

Yes, Python has several websocket libraries available, including AutobahnPython, WebSocket-Client, and Tornado.

What is AutobahnPython?

AutobahnPython is a mature websocket library for Python that supports both client and server implementations. It is widely regarded as the best websocket library for Python.