*******************************
How to Get Your Change Into Ryu
*******************************

Submitting a change
===================

Send patches to ryu-devel@lists.sourceforge.net. Please don't use "Pull
Request" on GitHub. We expect you to send patches in "git-format-patch"
style.

.. code-block:: bash

  # "N" means the number of commits to be included
  $ git format-patch -s HEAD~N

  # To add cover (e.g., [PATCH 0/X]), specify "--cover-letter" option
  $ git format-patch -s --cover-letter HEAD~N

  # You can send patches by "git send-email" command
  $ git send-email --to="ryu-devel@lists.sourceforge.net" *.patch

Please check your changes with autopep8, pycodestyle(pep8) and running
unit tests to make sure that they don't break the existing features.
The following command does all for you.

.. code-block:: bash

  # Install dependencies of tests
  $ pip install -r tools/test-requires

  # Execute autopep8
  # Also, it is convenient to add settings of your editor or IDE for
  # applying autopep8 automatically.
  $ autopep8 --recursive --in-place ryu/

  # Execute unit tests and pycodestyle(pep8)
  $ ./run_tests.sh

Of course, you are encouraged to add unit tests when you add new
features (it's not a must though).

Python version and libraries
============================
* Python 2.7, 3.4, 3.5:

  Ryu supports multiple Python version.  CI tests on Travis-CI is running
  on these versions.

* standard library + widely used library:

  Basically widely used == OpenStack adopted.
  As usual there are exceptions.  Or python binding library for other
  component.

Coding style guide
==================
* pep8:

  As python is used, PEP8 is would be hopefully mandatory for
  https://www.python.org/dev/peps/pep-0008/

* pylint:

  Although pylint is useful for finding bugs, but pylint score not very
  important for now because we're still at early development stage.
  https://www.pylint.org/

* Google python style guide is very helpful:
  http://google.github.io/styleguide/pyguide.html

* Guidelines derived from Guido's Recommendations:

  =============================   =================   ========
  Type                            Public              Internal
  =============================   =================   ========
  Packages                        lower_with_under
  Modules                         lower_with_under    _lower_with_under
  Classes                         CapWords            _CapWords
  Exceptions                      CapWords
  Functions                       lower_with_under()  _lower_with_under()
  Global/Class Constants          CAPS_WITH_UNDER     _CAPS_WITH_UNDER
  Global/Class Variables          lower_with_under    _lower_with_under
  Instance Variables              lower_with_under    _lower_with_under (protected) or __lower_with_under (private)
  Method Names                    lower_with_under()  _lower_with_under() (protected) or __lower_with_under() (private)
  Function/Method Parameters      lower_with_under
  Local Variables                 lower_with_under
  =============================   =================   ========

* OpenStack Nova style guide:
  https://github.com/openstack/nova/blob/master/HACKING.rst

* JSON files:

  Ryu source tree has JSON files under ryu/tests/unit/ofproto/json.
  They are used by unit tests.  To make patches easier to read,
  they are normalized using tools/normalize_json.py.  Please re-run
  the script before committing changes to these JSON files.

Reference
=========
* Python Essential Reference, 4th Edition [Amazon]
  * Paperback: 717 pages
  * Publisher: Addison-Wesley Professional; 4 edition (July 19, 2009)
  * Language: English
  * ISBN-10: 0672329786
  * ISBN-13: 978-0672329784

* The Python Standard Library by Example (Developer's Library)
  * Paperback: 1344 pages
  * Publisher: Addison-Wesley Professional; 1 edition (June 11, 2011)
  * Language: English
  * ISBN-10: 0321767349
  * ISBN-13: 978-0321767349
