Dealing with config files what's the options

[Tom Willis]

On Fri, 25 Feb 2005 15:02:04 -0700, Dave Brueck
<dave at pythonapocrypha.com> wrote:
> Jorgen Grahn wrote:
> > On Tue, 22 Feb 2005 20:38:28 -0500, Tom Willis <tom.willis at gmail.com> wrote:
> >
> >>How are the expert pythoneers dealing with config files?
> >
> > ...
> >
> >>Any ideas?
> >
> >
> > How about writing them in Python?
> 
> Depending on who will be editing the config files, this can be a great approach.
> 
> At the simplest level, a config.py file like this is so easy to use:
> 
> # Net settings
> timeoutSec = 5.3
> maxConnections = 3
> 
> # Other stuff
> foo = 'bar'
> 
> This type of a format is easy to use for just about anybody who has ever had to
> use config files before. What's nice is that the code to use it is
> straightforward too:
> 
> import config
> conn = config.maxConnections
> ...
> 
> A few times I've tried to use accessor functions to ensure that the values are
> present or valid or whatever, but I stopped doing that because in practice it's
> just not needed (again, for users who are familiar with the concept of config
> files).
> 
> A slightly more elaborate approach gives you full structure:
> 
> class Net:
>      maxConnections = 12
> 
> class System:
>      class Logging:
>          root = '/var/logs'
> 
> This prevents individual setting names from getting unwieldy, and the code that
> uses it can be pretty readable too:
> 
> logRoot = config.System.Logging.root
> 
> or, if there are lots of retrievals to do:
> 
> Logging = config.System.Logging
> logRoot = Logging.root
> ... etc ...
> 
> Using classes asks a little bit more of the users (they can break it a little
> more easily), but again, in practice it really hasn't been a problem at all.
> 
> -Dave
> --
> http://mail.python.org/mailman/listinfo/python-list
> 
I actually thought of this, and I was kind of on the fence due to the
intended audience.

I don't think it's too much to ask that they are comfy with the
concept of variables. I mean, if it was a shell script they'd be at
the top of the file anyway.

Then again I'm some what hesitant to help them make the connection
that I'm giving them the ability to indirectly edit the code. Kind of
like opening pandoras box. Once the figure out they can open any file
(*.py) with notepad, there will be utter anarchy and I'll get the call
at 4am that somethings wrong with the production data.



-- 
Thomas G. Willis
http://paperbackmusic.net