python-socketio

Python implementation of the Socket.IO realtime server.

Features

• Fully compatible with the Javascript, Swift, C++ and Java official Socket.IO clients, plus any third party clients that comply with the Socket.IO specification.
• Compatible with Python 2.7 and Python 3.3+.
• Supports large number of clients even on modest hardware when used with an asynchronous server based on eventlet or gevent. For development and testing, any WSGI complaint multi-threaded server can be used.
• Includes a WSGI middleware that integrates Socket.IO traffic with standard WSGI applications.
• Broadcasting of messages to all connected clients, or to subsets of them assigned to "rooms".
• Optional support for multiple servers, connected through a messaging queue such as Redis or RabbitMQ.
• Send messages to clients from external processes, such as Celery workers or auxiliary scripts.
• Event-based architecture implemented with decorators that hides the details of the protocol.
• Support for HTTP long-polling and WebSocket transports.
• Support for XHR2 and XHR browsers.
• Support for text and binary messages.
• Support for gzip and deflate HTTP compression.
• Configurable CORS responses, to avoid cross-origin problems with browsers.

Example

The following application uses Flask to serve the HTML/Javascript to the client:

import socketio
import eventlet
from flask import Flask, render_template

sio = socketio.Server()
app = Flask(__name__)

@app.route('/')
def index():
    """Serve the client-side application."""
    return render_template('index.html')

@sio.on('connect', namespace='/chat')
def connect(sid, environ):
    print("connect ", sid)

@sio.on('chat message', namespace='/chat')
def message(sid, data):
    print("message ", data)
    sio.emit(sid, 'reply')

@sio.on('disconnect', namespace='/chat')
def disconnect(sid):
    print('disconnect ', sid)

if __name__ == '__main__':
    # wrap Flask application with engineio's middleware
    app = socketio.Middleware(sio, app)

    # deploy as an eventlet WSGI server
    eventlet.wsgi.server(eventlet.listen(('', 8000)), app)

Resources

• Documentation
• PyPI