websocket-client

websocket-client is a WebSocket client for Python. It provides access
to low level APIs for WebSockets. websocket-client implements version
hybi-13
of the WebSocket protocol. This client does not currently support the
permessage-deflate extension from
RFC 7692.

Documentation

This project’s documentation can be found at
https://websocket-client.readthedocs.io/

Contributing

Please see the contribution guidelines

Installation

You can use pip install websocket-client to install, or pip install -e .
to install from a local copy of the code. This module is tested on Python 3.8+.

There are several optional dependencies that can be installed to enable
specific websocket-client features.

• To install python-socks for proxy usage and wsaccel for a minor performance boost, use:
  pip install websocket-client[optional]
• To install websockets to run unit tests using the local echo server, use:
  pip install websocket-client[test]
• To install Sphinx and sphinx_rtd_theme to build project documentation, use:
  pip install websocket-client[docs]

While not a strict dependency, rel
is useful when using run_forever with automatic reconnect. Install rel with pip install rel.

Footnote: Some shells, such as zsh, require you to escape the [ and ] characters with a \.

Usage Tips

Check out the documentation’s FAQ for additional guidelines:
https://websocket-client.readthedocs.io/en/latest/faq.html

Known issues with this library include lack of WebSocket Compression
support (RFC 7692) and minimal threading documentation/support.

Performance

The send and validate_utf8 methods can sometimes be bottleneck.
You can disable UTF8 validation in this library (and receive a
performance enhancement) with the skip_utf8_validation parameter.
If you want to get better performance, install wsaccel. While
websocket-client does not depend on wsaccel, it will be used if
available. wsaccel doubles the speed of UTF8 validation and
offers a very minor 10% performance boost when masking the
payload data as part of the send process. Numpy used to
be a suggested performance enhancement alternative, but
issue #687
found it didn’t help.

Examples

Many more examples are found in the
examples documentation.

Long-lived Connection

Most real-world WebSockets situations involve longer-lived connections.
The WebSocketApp run_forever loop will automatically try to reconnect
to an open WebSocket connection when a network
connection is lost if it is provided with:

• a dispatcher argument (async dispatcher like rel or pyevent)
• a non-zero reconnect argument (delay between disconnection and attempted reconnection)

run_forever provides a variety of event-based connection controls
using callbacks like on_message and on_error.
run_forever does not automatically reconnect if the server
closes the WebSocket gracefully (returning
a standard websocket close code).
This is the logic behind the decision.
Customizing behavior when the server closes
the WebSocket should be handled in the on_close callback.
This example uses rel
for the dispatcher to provide automatic reconnection.

import websocket
import _thread
import time
import rel

def on_message(ws, message):
    print(message)

def on_error(ws, error):
    print(error)

def on_close(ws, close_status_code, close_msg):
    print("### closed ###")

def on_open(ws):
    print("Opened connection")

if __name__ == "__main__":
    websocket.enableTrace(True)
    ws = websocket.WebSocketApp("wss://api.gemini.com/v1/marketdata/BTCUSD",
                              on_open=on_open,
                              on_message=on_message,
                              on_error=on_error,
                              on_close=on_close)

    ws.run_forever(dispatcher=rel, reconnect=5)  # Set dispatcher to automatic reconnection, 5 second reconnect delay if connection closed unexpectedly
    rel.signal(2, rel.abort)  # Keyboard Interrupt
    rel.dispatch()

Short-lived Connection

This is if you want to communicate a short message and disconnect
immediately when done. For example, if you want to confirm that a WebSocket
server is running and responds properly to a specific request.

from websocket import create_connection

ws = create_connection("ws://echo.websocket.events/")
print(ws.recv())
print("Sending 'Hello, World'...")
ws.send("Hello, World")
print("Sent")
print("Receiving...")
result =  ws.recv()
print("Received '%s'" % result)
ws.close()