Open Stack

On Tue, 14 Oct 2014 12:28:29 PM Angus Lees wrote:
> (Context: https://review.openstack.org/#/c/117418/)
> 
> I'm looking for some rough consensus on what naming conventions we want for
> unused variables in Neutron, and across the larger OpenStack python codebase
> since there's no reason for Neutron to innovate here.

So after carefully collecting and summarising all one opinion[1], we're going 
with:

 __ (double-underscore) and
 _foo (leading underscore)


[1] Next time I'll be sure to mention docker in the subject line ;)

 - Gus

> As far as I can see, there are two cases:
> 
> 
> 1.  The "I just don't care" variable
> 
> Eg:    _, _, filename = path.rpartition('/')
> 
> In python this is very commonly '_', but this conflicts with the gettext
> builtin so we should avoid it in OpenStack.
> 
> Possible candidates include:
> 
> a.  'x'
> b. '__'  (double-underscore)
> c. No convention
> 
> 
> 2.  "I know it is unused, but the name still serves as documentation"
> 
> Note this turns up as two cases: as a local, and as a function parameter.
> 
> Eg:   out, _err = execute('df', path)
> 
> Eg:   def makefile(self, _mode, _other):
>             return self._buffer
> 
> I deliberately chose that second example to highlight that the leading-
> underscore convention collides with its use for private properties.
> 
> Possible candidates include:
> 
> a. _foo   (leading-underscore, note collides with private properties)
> b. unused_foo   (suggested in the Google python styleguide)
> c. NOQA_foo   (as suggested in c/117418)
> d. No convention  (including not indicating that variables are known-unused)
> 
> 
> As with all style discussions, everyone feels irrationally attached to their
> favourite, but the important bit is to be consistent to aid readability 
> (and in this case, also to help the mechanical code checkers).
> 
> Vote / Discuss / Suggest additional alternatives.

-- 
 - Gus