A minimal Websockets Server in Python with no external dependencies.
- Python3.6+
- Clean simple API
- Multiple clients
- No dependencies
Notice that this implementation does not support the more advanced features like multithreading etc. The project is focused mainly on making it easy to run a websocket server for prototyping, testing or for making a GUI for your application.
Install with pip
pip install websocket-server
For coding details have a look at the server.py example and the API.
You can get a feel of how to use the websocket server by running
python server.py
Then just open client.html in your browser and you should be able to send and receive messages.
Run all tests
pytest
The API is simply methods and properties of the WebsocketServer class.
The WebsocketServer can be initialized with the below parameters.
port - The port clients will need to connect to.
host - By default the 127.0.0.1 is used which allows connections only from the current machine. If you wish to allow all network machines to connect, you need to pass 0.0.0.0 as hostname.
loglevel - logging level to print. By default WARNING is used. You can use logging.DEBUG or logging.INFO for more verbose output.
key - If using SSL, this is the path to the key.
cert - If using SSL, this is the path to the certificate.
| Property | Description |
|---|---|
| clients | A list of client |
| Method | Description | Takes | Gives |
|---|---|---|---|
run_forever() |
Runs server until shutdown_gracefully or shutdown_abruptly are called. | threaded: run server on its own thread if True | None |
set_fn_new_client() |
Sets a callback function that will be called for every new client connecting to us |
function | None |
set_fn_client_left() |
Sets a callback function that will be called for every client disconnecting from us |
function | None |
set_fn_message_received() |
Sets a callback function that will be called when a client sends a message |
function | None |
send_message() |
Sends a message to a specific client. The message is a simple string. |
client, message | None |
send_message_to_all() |
Sends a message to all connected clients. The message is a simple string. |
message | None |
shutdown_gracefully() |
Shutdown server by sending a websocket CLOSE handshake to all connected clients. | None | None |
shutdown_abruptly() |
Shutdown server without sending any websocket CLOSE handshake. | None | None |
| Set by | Description | Parameters |
|---|---|---|
set_fn_new_client() |
Called for every new client connecting to us |
client, server |
set_fn_client_left() |
Called for every client disconnecting from us |
client, server |
set_fn_message_received() |
Called when a client sends a message |
client, server, message |
The client passed to the callback is the client that left, sent the message, etc. The server might not have any use to use. However it is passed in case you want to send messages to clients.
Example:
import logging
from websocket_server import WebsocketServer
def new_client(client, server):
server.send_message_to_all("Hey all, a new client has joined us")
server = WebsocketServer(host='127.0.0.1', port=13254, loglevel=logging.INFO)
server.set_fn_new_client(new_client)
server.run_forever()Example (SSL):
import logging
from websocket_server import WebsocketServer
def new_client(client, server):
server.send_message_to_all("Hey all, a new client has joined us")
server = WebsocketServer(host='127.0.0.1', port=13254, loglevel=logging.INFO, key="key.pem", cert="cert.pem")
server.set_fn_new_client(new_client)
server.run_forever()Client is just a dictionary passed along methods.
{
'id' : client_id,
'handler' : client_handler,
'address' : (addr, port)
}