8ee272abe7
Fix the old or invalid http url links in docs. Change-Id: Iea99aba898a76b5c59db45719640fad8f4a5f684
289 lines
8.3 KiB
ReStructuredText
289 lines
8.3 KiB
ReStructuredText
Zaqar Style Commandments
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========================
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- Step 1: Read http://www.python.org/dev/peps/pep-0008/
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- Step 2: Read http://www.python.org/dev/peps/pep-0008/ again
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- Step 3: Read on
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**Table of Contents**
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.. contents::
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:local:
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:depth: 2
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:backlinks: none
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General
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-------
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- Optimize for readability; whitespace is your friend.
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- Put two newlines between top-level code (funcs, classes, etc.)
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- Put one newline between methods in classes and anywhere else.
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- Use blank lines to group related logic.
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- Never write ``except:`` (use ``except Exception:`` instead, at
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the very least).
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- All classes must inherit from ``object`` (explicitly).
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- Use single-quotes for strings unless the string contains a
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single-quote.
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- Use the double-quote character for blockquotes (``"""``, not ``'''``)
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- USE_ALL_CAPS_FOR_GLOBAL_CONSTANTS
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Comments
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--------
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- In general use comments as "memory pegs" for those coming after you up
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the trail.
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- Guide the reader though long functions with a comments introducing
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different sections of the code.
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- Choose clean, descriptive names for functions and variables to make
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them self-documenting.
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- Include your name with TODOs as in ``# TODO(termie): blah blah...``.
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- Add ``# NOTE(termie): blah blah...`` comments to clarify your intent, or
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to explain a tricky algorithm, when it isn't obvious from just reading
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the code.
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Identifiers
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-----------
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- Do not give anything the same name as a built-in or reserved word.
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- Don't use single characters in identifiers except in trivial loop variables and mathematical algorithms.
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- Avoid abbreviations, especially if they are ambiguous or their meaning would not be immediately clear to the casual reader or newcomer.
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Wrapping
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--------
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Wrap long lines by using Python's implied line continuation inside
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parentheses, brackets and braces. Make sure to indent the continued
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line appropriately. The preferred place to break around a binary
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operator is after the operator, not before it.
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Example::
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class Rectangle(Blob):
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def __init__(self, width, height,
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color='black', emphasis=None, highlight=0):
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# More indentation included to distinguish this from the rest.
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if (width == 0 and height == 0 and
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color == 'red' and emphasis == 'strong' or
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highlight > 100):
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raise ValueError('sorry, you lose')
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if width == 0 and height == 0 and (color == 'red' or
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emphasis is None):
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raise ValueError("I don't think so -- values are %s, %s" %
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(width, height))
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msg = ('this is a very long string that goes on and on and on and'
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'on and on and on...')
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super(Rectangle, self).__init__(width, height,
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color, emphasis, highlight)
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Imports
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-------
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- Only modules may be imported
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- Do not make relative imports
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- Order your imports by the full module path
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- Classes and functions may be hoisted into a package namespace, via __init__ files, with some discretion.
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- Organize your imports according to the template given below
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Template::
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{{stdlib imports in human alphabetical order}}
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\n
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{{third-party lib imports in human alphabetical order}}
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\n
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{{zaqar imports in human alphabetical order}}
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\n
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\n
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{{begin your code}}
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Human Alphabetical Order Examples
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---------------------------------
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Example::
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import logging
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import time
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import unittest
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import eventlet
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import zaqar.common
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from zaqar import test
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import zaqar.transport
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More Import Examples
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--------------------
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**INCORRECT** ::
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import zaqar.transport.wsgi as wsgi
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**CORRECT** ::
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from zaqar.transport import wsgi
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Docstrings
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----------
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Docstrings are required for all functions and methods.
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Docstrings should ONLY use triple-double-quotes (``"""``)
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Single-line docstrings should NEVER have extraneous whitespace
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between enclosing triple-double-quotes.
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**INCORRECT** ::
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""" There is some whitespace between the enclosing quotes :( """
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**CORRECT** ::
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"""There is no whitespace between the enclosing quotes :)"""
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Docstrings should document default values for named arguments
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if they're not None
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Docstrings that span more than one line should look like this:
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Example::
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"""Single-line summary, right after the opening triple-double-quote.
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If you are going to describe parameters and return values, use Sphinx; the
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appropriate syntax is as follows.
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:param foo: the foo parameter
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:param bar: (Default True) the bar parameter
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:param foo_long_bar: the foo parameter description is very
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long so we have to split it in multiple lines in order to
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keey things ordered
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:returns: return_type -- description of the return value
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:returns: description of the return value
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:raises: AttributeError, KeyError
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"""
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**DO NOT** leave an extra newline before the closing triple-double-quote.
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Dictionaries/Lists
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------------------
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If a dictionary (dict) or list object is longer than 80 characters, its items
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should be split with newlines. Embedded iterables should have their items
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indented. Additionally, the last item in the dictionary should have a trailing
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comma. This increases readability and simplifies future diffs.
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Example::
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my_dictionary = {
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"image": {
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"name": "Just a Snapshot",
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"size": 2749573,
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"properties": {
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"user_id": 12,
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"arch": "x86_64",
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},
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"things": [
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"thing_one",
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"thing_two",
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],
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"status": "ACTIVE",
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},
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}
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Calling Methods
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---------------
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Calls to methods 80 characters or longer should format each argument with
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newlines. This is not a requirement, but a guideline::
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unnecessarily_long_function_name('string one',
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'string two',
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kwarg1=constants.ACTIVE,
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kwarg2=['a', 'b', 'c'])
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Rather than constructing parameters inline, it is better to break things up::
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list_of_strings = [
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'what_a_long_string',
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'not as long',
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]
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dict_of_numbers = {
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'one': 1,
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'two': 2,
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'twenty four': 24,
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}
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object_one.call_a_method('string three',
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'string four',
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kwarg1=list_of_strings,
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kwarg2=dict_of_numbers)
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Internationalization (i18n) Strings
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-----------------------------------
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In order to support multiple languages, we have a mechanism to support
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automatic translations of exception and log strings.
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Example::
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msg = _("An error occurred")
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If you have a variable to place within the string, first internationalize the
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template string then do the replacement.
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Example::
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msg = _("Missing parameter: %s") % ("flavor",)
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LOG.error(msg)
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If you have multiple variables to place in the string, use keyword parameters.
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This helps our translators reorder parameters when needed.
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Example::
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msg = _("The server with id %(s_id)s has no key %(m_key)s")
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LOG.error(msg % {"s_id": "1234", "m_key": "imageId"})
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An important exception to this rule is with regards to exceptions:
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exceptions should NOT be marked as translatable. See `No Exceptions i18n`_
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for more details.
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.. _No Exceptions i18n: https://trello.com/card/exceptions-should-not-be-marked-as-translatable/511403287d138cd6200078e0/243
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Creating Unit Tests
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-------------------
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For every any change, unit tests should be created that both test and
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(implicitly) document the usage of said feature. If submitting a patch for a
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bug that had no unit test, a new passing unit test should be added. If a
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submitted bug fix does have a unit test, be sure to add a new one that fails
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without the patch and passes with the patch.
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NOTE: 100% coverage is required
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openstack-common
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----------------
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A number of modules from openstack-common are imported into the project.
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These modules are "incubating" in openstack-common and are kept in sync
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with the help of openstack-common's update.py script. See:
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https://wiki.openstack.org/wiki/CommonLibrary#Incubation
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The copy of the code should never be directly modified here. Please
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always update openstack-common first and then run the script to copy
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the changes across.
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Logging
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-------
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Use __name__ as the name of your logger and name your module-level logger
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objects 'LOG'::
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LOG = logging.getLogger(__name__)
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