OpenStack Style Commandments

============================

Step 1: Read http://www.python.org/dev/peps/pep-0008/

Step 2: Read http://www.python.org/dev/peps/pep-0008/ again

Step 3: Read on

Imports

-------

- thou shalt not import objects, only modules

- thou shalt not import more than one module per line

- thou shalt not make relative imports

- thou shalt organize your imports according to the following template

::

# vim: tabstop=4 shiftwidth=4 softtabstop=4

{{stdlib imports in human alphabetical order}}

\n

{{3rd-party imports in human alphabetical order}}

\n

{{openstack imports in human alphabetical order}}

\n

\n

{{begin your code}}

General

-------

- thou shalt put two newlines twixt toplevel code (funcs, classes, etc)

- thou shalt put one newline twixt methods in classes and anywhere else

- thou shalt not write "except:", use "except Exception:" at the very least

- thou shalt include your name with TODOs as in "TODO(termie)"

- thou shalt not name anything the same name as a builtin or reserved word

- thou shalt not violate causality in our time cone, or else

Human Alphabetical Order Examples

---------------------------------

::

import httplib

import logging

import random

import StringIO

import testtools

import time

from nova import flags

from nova import test

from nova.auth import users

from nova.endpoint import api

from nova.endpoint import cloud

Docstrings

----------

"""A one line docstring looks like this and ends in a period."""

"""A multiline docstring has a one-line summary, less than 80 characters.

Then a new paragraph after a newline that explains in more detail any

general information about the function, class or method. Example usages

are also great to have here if it is a complex class for function. After

you have finished your descriptions add an extra newline and close the

quotations.

When writing the docstring for a class, an extra line should be placed

after the closing quotations. For more in-depth explanations for these

decisions see http://www.python.org/dev/peps/pep-0257/

If you are going to describe parameters and return values, use Sphinx, the

appropriate syntax is as follows.

:param foo: the foo parameter

:param bar: the bar parameter

:returns: description of the return value

"""

Text encoding

----------

- All text within python code should be of type 'unicode'.

WRONG:

>>> s = 'foo'

>>> s

'foo'

>>> type(s)

<type 'str'>

RIGHT:

>>> u = u'foo'

>>> u

u'foo'

>>> type(u)

<type 'unicode'>

- Transitions between internal unicode and external strings should always

be immediately and explicitly encoded or decoded.

- All external text that is not explicitly encoded (database storage,

commandline arguments, etc.) should be presumed to be encoded as utf-8.

WRONG:

mystring = infile.readline()

myreturnstring = do_some_magic_with(mystring)

outfile.write(myreturnstring)

RIGHT:

mystring = infile.readline()

mytext = s.decode('utf-8')

returntext = do_some_magic_with(mytext)

returnstring = returntext.encode('utf-8')

outfile.write(returnstring)

Running Tests

-------------

The testing system is based on a combination of tox and testr. If you just

want to run the whole suite, run `tox` and all will be fine. However, if

you'd like to dig in a bit more, you might want to learn some things about

testr itself. A basic walkthrough for OpenStack can be found at

http://wiki.openstack.org/testr