How to detect my OS info?

[Peter Wu]

Hello, 

I use Windows and FreeBSD interchangeably. I want to write a .signature
script that can detect my OS respectively. 

Under FreeBSD, I can fire 'uname -rs' to get the information I need and
under Windows, I may need to leverage 'ver' to get the info.

Is there a one-stop solution from Python? I mean I just write one python
script and it can work both on Windows and FreeBSD? Thanks.

-- 
Peter Wu