Python implementation of the Socket.IO realtime server.
- 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.
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)