Newbie: freebsd admin scripting

[Muffin]

I am using python for the first time on Unix and on FBSD. I need a few 
pointer, tips or tricks on scripting on config files. Mostly admin type 
configs like the rc.conf file usually setup like:

someiteam=somevalue        #sometype of description

Where I would like to toggle the somevalue in an easy way. I realize I 
could parse it with reg expression but that sounds kinda complicated. Is 
there an easer way a Unix python way of dealing with these type of 
config files.

I found a built in mod for parseconfig but it deal with .ini file styles 
(windows) that include a [section] header as well as uses 
someiteam=somevalue format. I believe it requires the header though.

Books or howtos regarding Unix admin scripting(python) would be great. 
Is this type of scripting mainly executing a Unix command and capturing 
and parsing its output like this:

x=command.getoutput("ifconfig")

and them parsing x for what I want or is there a name space I can call 
to get , for example, a list of all interfaces?

I have mainly used python in windows using the com space or win32 api 
aside from the base python lib, on Unix I am lost on what to do or how 
things are generally done. Advise on how to "think" in Unix python terms 
if that makes any sense.

Thx