========
 gevent
========

gevent_ is a coroutine-based Python networking library.

Features include:

* Fast event loop based on libev_ or libuv_.
* Lightweight execution units based on greenlet_.
* Familiar API that re-uses concepts from the Python standard library.
* Cooperative sockets with SSL support.
* DNS queries performed through c-ares_ or a threadpool.
* Ability to use standard library and 3rd party modules written for standard blocking sockets

gevent is `inspired by eventlet`_ but features more consistent API,
simpler implementation and better performance. Read why others `use
gevent`_ and check out the list of the `open source projects based on
gevent`_.

gevent was written by `Denis Bilenko <http://denisbilenko.com/>`_.

Since version 1.1, gevent is maintained by `NextThought
<https://nextthought.com>`_ with help from the `contributors
<https://github.com/gevent/gevent/graphs/contributors>`_ and is
licensed under the MIT license.

See `what's new`_ in the latest major release.

Check out the detailed changelog_ for this version.

Get gevent
==========

gevent runs on Python >= 2.7, Python >= 3.4, or PyPy >= 5.5 (including
PyPy2 and PyPy3). On all platforms, installing setuptools is required
(this is done automatically if working in a virtual environment).

You can use pip to install gevent::

    pip install gevent

.. tip:: You need Pip 8.0 or later to install the binary wheels.

.. tip:: You need to install from source, not the manylinux wheels, to
         use the libuv backend.

Download the latest release from `Python Package Index`_ or clone `the repository`_.

Read the documentation online at http://www.gevent.org. Additional
installation information can be found `here <http://www.gevent.org/intro.html#installation-and-requirements>`_.

Post feedback and issues on the `bug tracker`_, `mailing list`_, blog_
and `twitter (@gevent)`_.


Development
===========

To install the latest development version::

  pip install setuptools cffi 'cython>=0.27' git+git://github.com/gevent/gevent.git#egg=gevent

To hack on gevent (using a virtualenv)::

  $ git clone https://github.com/gevent/gevent.git
  $ cd gevent
  $ virtualenv env
  $ source env/bin/activate
  (env) $ pip install -r dev-requirements.txt

.. note::

   You must have a C compiler, Cython, and the Python development headers
   installed to build a checkout. Installing CFFI on CPython (it's
   standard on PyPy) allows building the CFFI backends for testing, and
   tox is the command used to test multiple versions of Python.


Running Tests
-------------

There are a few different ways to run the tests. To simply run the
tests on one version of Python during development, try this::

  python setup.py develop
  cd src/greentest
  PYTHONPATH=.. python testrunner.py --config known_failures.py

Before submitting a pull request, it's a good idea to run the tests
across all supported versions of Python, and to check the code quality
using prospector. This is what is done on Travis CI. Locally it
can be done using tox::

  pip install tox
  tox

The testrunner accepts a ``--coverage`` argument to enable code
coverage metrics through the `coverage.py`_ package. That would go
something like this::

  cd src/greentest
  PYTHONPATH=.. python testrunner.py --config known_failures.py --coverage
  coverage combine
  coverage html -i
  <open htmlcov/index.html>

Builds on Travis CI automatically submit updates to `coveralls.io`_ to
monitor test coverage.

.. image:: https://coveralls.io/repos/gevent/gevent/badge.svg?branch=master&service=github
   :target: https://coveralls.io/github/gevent/gevent?branch=master

.. note:: On Debian, you will probably need ``libpythonX.Y-testsuite``
          installed to run all the tests.

Continuous integration
----------------------

A test suite is run for every push and pull request submitted. Travis
CI is used to test on Linux, and `AppVeyor`_ runs the builds on
Windows.

.. image:: https://travis-ci.org/gevent/gevent.svg?branch=master
   :target: https://travis-ci.org/gevent/gevent

.. image:: https://ci.appveyor.com/api/projects/status/q4kl21ng2yo2ixur?svg=true
   :target: https://ci.appveyor.com/project/denik/gevent

.. _gevent: http://www.gevent.org
.. _greenlet: http://pypi.python.org/pypi/greenlet
.. _libev: http://libev.schmorp.de/
.. _libuv: http://libuv.org/
.. _c-ares: http://c-ares.haxx.se/
.. _inspired by eventlet: http://blog.gevent.org/2010/02/27/why-gevent/
.. _use gevent: http://groups.google.com/group/gevent/browse_thread/thread/4de9703e5dca8271
.. _open source projects based on gevent: https://github.com/gevent/gevent/wiki/Projects
.. _Python Package Index: http://pypi.python.org/pypi/gevent
.. _the repository: https://github.com/gevent/gevent
.. _bug tracker: https://github.com/gevent/gevent/wiki/Projects
.. _mailing list: http://groups.google.com/group/gevent
.. _blog: http://blog.gevent.org
.. _twitter (@gevent): http://twitter.com/gevent
.. _coverage.py: https://pypi.python.org/pypi/coverage/
.. _coveralls.io: https://coveralls.io/github/gevent/gevent
.. _AppVeyor: https://ci.appveyor.com/project/denik/gevent
.. _what's new: http://www.gevent.org/whatsnew_1_3.html
.. _changelog: http://www.gevent.org/changelog.html