python-openstackclient/HACKING.rst

OpenStack Style Commandments

• Step 1: Read the OpenStack Style Commandments http://docs.openstack.org/developer/hacking/
• Step 2: Read on

Deviations from Global Hacking

The following checks are specifically skipped in OpenStackClient:

* H305 - py2/py3 compatibility problems
* H307 - py2/py3 compatibility problems
* H402 - one line docstring ends in period
* H904 - backslash continuation line

General

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

Docstrings

Docstrings should ONLY use triple-double-quotes (""")

Single-line docstrings should NEVER have extraneous whitespace between enclosing triple-double-quotes.

Deviation! Sentence fragments do not have punctuation. Specifically in the command classes the one line docstring is also the help string for that command and those do not have periods.

"""A one line docstring looks like this"""

Calling Methods

Deviation! When breaking up method calls due to the 79 char line length limit, use the alternate 4 space indent. With the first argument on the succeeding line all arguments will then be vertically aligned. Use the same convention used with other data structure literals and terminate the method call with the last argument line ending with a comma and the closing paren on its own line indented to the starting line level.

unnecessarily_long_function_name(

'string one', 'string two', kwarg1=constants.ACTIVE, kwarg2=['a', 'b', 'c'],

)

Text encoding

Note: this section clearly has not been implemented in this project yet, it is the intention to do so.

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:

infile = open('testfile', 'r') mystring = infile.readline() myreturnstring = do_some_magic_with(mystring) outfile.write(myreturnstring)

RIGHT:

infile = open('testfile', 'r') mystring = infile.readline() mytext = mystring.decode('utf-8') returntext = do_some_magic_with(mytext) returnstring = returntext.encode('utf-8') outfile.write(returnstring)

Python 3.x Compatibility

OpenStackClient strives to be Python 3.3 compatible. Common guidelines:

• Convert print statements to functions: print statements should be converted to an appropriate log or other output mechanism.
• Use six where applicable: x.iteritems is converted to six.iteritems(x) for example.

Running Tests

Note: Oh boy, are we behind on writing tests. But they are coming!

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