=================
Python SSE Client
This is a Python client library for iterating over http Server Sent Event (SSE)
streams (also known as EventSource, after the name of the Javascript interface
inside browsers). The SSEClient class accepts a url on init, and is then an
iterator over messages coming from the server.
Installation
Use pip::
pip install sseclient
Usage
::
from sseclient import SSEClient
messages = SSEClient('http://mysite.com/sse_stream/')
for msg in messages:
do_something_useful(msg)
Each message object will have a 'data' attribute, as well as optional 'event',
'id', and 'retry' attributes.
Optional init parameters:
-
last_id: If provided, this parameter will be sent to the server to tell it to
return only messages more recent than this ID.
-
retry: Number of milliseconds to wait after disconnects before attempting to
reconnect. The server may change this by including a 'retry' line in a
message. Retries are handled automatically by the SSEClient object.
You may also provide any additional keyword arguments supported by the
Requests_ library, such as a 'headers' dict and a (username, password) tuple
for 'auth'.
Development
Install the library in editable mode::
pip install -e .
Install the test dependencies::
pip install pytest backports.unittest_mock
Run the tests with py.test::
(sseclient)vagrant sseclient $ py.test
===================== test session starts ======================
platform linux2 -- Python 2.7.6 -- py-1.4.30 -- pytest-2.7.2
rootdir: /vagrant/code/sseclient, inifile:
plugins: backports.unittest-mock
collected 11 items
test_sseclient.py ...........
================== 11 passed in 0.19 seconds ===================
There are a couple TODO items in the code for getting the implementation
completely in line with the finer points of the SSE spec.
Additional Resources
HTML5Rocks Tutorial
_Official SSE Spec
_
.. _Requests: https://requests.readthedocs.io/
.. _HTML5Rocks Tutorial: https://www.html5rocks.com/en/tutorials/eventsource/basics/
.. _Official SSE Spec: https://html.spec.whatwg.org/multipage/comms.html#server-sent-events