Obtaining offset given location string (via library call?)

[Clark C . Evans]

Hello.  I'm looking for a "C" function I can call
(ideally from Python, but I can write a wrapper) which
returns for me the current offset from UTC given one
of the location strings, such as "Australia/Sydney".

Any ideas?  I was very hopeful with "zdump" however
what I need is the offset (yes, I could probably 
hack the offset from the output of zdump) and further,
I'd rather not have to start a new process to obtain
this information, thus having it in library form would
be perfect.

Thank you so much!

Clark