keystone/HACKING.rst

Keystone Style Commandments

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

Keystone Specific Commandments

• Avoid using "double quotes" where you can reasonably use 'single quotes'

TODO vs FIXME

• TODO(name): implies that something should be done (cleanup, refactoring, etc), but is expected to be functional.
• FIXME(name): implies that the method/function/etc shouldn't be used until that code is resolved and bug fixed.

Logging

Use the common logging module, and ensure you getLogger:

from keystone.openstack.common import log

LOG = log.getLogger(__name__)

LOG.debug('Foobar')

AssertEqual argument order

assertEqual method's arguments should be in ('expected', 'actual') order.

Properly Calling Callables

Methods, functions and classes can specify optional parameters (with default values) using Python's keyword arg syntax. When providing a value to such a callable we prefer that the call also uses keyword arg syntax. For example:

def f(required, optional=None):
    pass

# GOOD
f(0, optional=True)

# BAD
f(0, True)

This gives us the flexibility to re-order arguments and more importantly to add new required arguments. It's also more explicit and easier to read.