circuits

.. _Python Programming Language: http://www.python.org/ .. _#circuits IRC Channel: https://web.libera.chat/#circuits .. _Libera.Chat IRC Network: https://libera.chat .. _Python Standard Library: http://docs.python.org/library/ .. _MIT License: http://www.opensource.org/licenses/mit-license.php .. _Create an Issue: https://github.com/circuits/circuits/issues/new .. _Mailing List: http://groups.google.com/group/circuits-users .. _Website: http://circuitsframework.com/ .. _PyPi: http://pypi.python.org/pypi/circuits .. _Documentation: http://circuits.readthedocs.org/en/latest/ .. _Downloads: https://github.com/circuits/circuits/releases .. _Ask a Question: http://stackoverflow.com/questions/ask .. _Stackoverflow: http://stackoverflow.com/

.. image:: https://github.com/circuits/circuits/actions/workflows/python-app.yml/badge.svg :target: https://github.com/circuits/circuits/actions/workflows/python-app.yml :alt: Build Status

.. image:: https://codecov.io/gh/circuits/circuits/branch/master/graph/badge.svg :target: https://codecov.io/gh/circuits/circuits :alt: Coverage

circuits is a Lightweight Event driven and Asynchronous Application Framework for the Python Programming Language_ with a strong Component Architecture.

circuits also includes a lightweight, high performance and scalable HTTP/WSGI compliant web server as well as various I/O and Networking components.

• Website_
• Downloads_
• Documentation_

Got questions?

• Ask a Question_ (Tag it: circuits-framework)

Examples

Hello .....

.. code:: python

#!/usr/bin/env python

"""circuits Hello World"""

from circuits import Component, Event


class hello(Event):
    """hello Event"""


class App(Component):

    def hello(self):
        """Hello Event Handler"""

        print("Hello World!")

    def started(self, component):
        """Started Event Handler

        This is fired internally when your application starts up and can be used to
        trigger events that only occur once during startup.
        """

        self.fire(hello())  # Fire hello Event

        raise SystemExit(0)  # Terminate the Application

App().run()

Echo Server ...........

.. code:: python

#!/usr/bin/env python

"""Simple TCP Echo Server

This example shows how you can create a simple TCP Server (an Echo Service)
utilizing the builtin Socket Components that the circuits library ships with.
"""

from circuits import handler, Debugger
from circuits.net.sockets import TCPServer


class EchoServer(TCPServer):

    @handler("read")
    def on_read(self, sock, data):
        """Read Event Handler

        This is fired by the underlying Socket Component when there has been
        new data read from the connected client.

        ..note :: By simply returning, client/server socket components listen
                  to ValueChagned events (feedback) to determine if a handler
                  returned some data and fires a subsequent Write event with
                  the value returned.
        """

        return data

# Start and "run" the system.
# Bind to port 0.0.0.0:8000
app = EchoServer(8000)
Debugger().register(app)
app.run()

Hello Web .........

.. code:: python

#!/usr/bin/env python

from circuits.web import Server, Controller


class Root(Controller):

    def index(self):
        """Index Request Handler

        Controller(s) expose implicitly methods as request handlers.
        Request Handlers can still be customized by using the ``@expose``
        decorator. For example exposing as a different path.
        """

        return "Hello World!"

app = Server(("0.0.0.0", 8000))
Root().register(app)
app.run()

More examples <https://github.com/circuits/circuits/tree/master/examples>_...

Features

• event driven
• concurrency support
• component architecture
• asynchronous I/O components
• no required external dependencies
• full featured web framework (circuits.web)
• coroutine based synchronization primitives

Requirements

• circuits has no dependencies beyond the Python Standard Library_.

Supported Platforms

• Linux, FreeBSD, Mac OS X, Windows
• Python 3.7, 3.8, 3.9, 3.10, 3.11, 3.12
• pypy (the newer the better)

Installation

The simplest and recommended way to install circuits is with pip. You may install the latest stable release from PyPI with pip::

$ pip install circuits

If you do not have pip, you may use easy_install::

$ easy_install circuits

Alternatively, you may download the source package from the PyPi_ or the Downloads_ extract it and install using::

$ python setup.py install

.. note:: You can install the development version <https://github.com/circuits/circuits/archive/master.zip#egg=circuits-dev>_ via pip install circuits==dev.

License

circuits is licensed under the MIT License_.

Feedback

We welcome any questions or feedback about bugs and suggestions on how to improve circuits.

Let us know what you think about circuits. @pythoncircuits <http://twitter.com/pythoncircuits>_.

Do you have suggestions for improvement? Then please Create an Issue_ with details of what you would like to see. I'll take a look at it and work with you to either incorporate the idea or find a better solution.

Community

There are also several places you can reach out to the circuits community:

• Mailing List_
• #circuits IRC Channel_ on the Libera.Chat IRC Network_
• Ask a Question_ on Stackoverflow_ (Tag it: circuits-framework)

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Disclaimer

Whilst I (James Mills) continue to contribute and maintain the circuits project I do not represent the interests or business of my employer Facebook Inc. The contributions I make are of my own free time and have no bearing or relevance to Facebook Inc.