How to check if OS is Vista in Python?

Question

How, in the simplest possible way, distinguish between Windows XP and Windows Vista, using Python and pywin32 or wxPython?

Essentially, I need a function that called

Answer 1

The solution used in Twisted, which doesn't need pywin32:

def isVista():
    if getattr(sys, "getwindowsversion", None) is not None:
        return sys.getwindowsversion()[0] == 6
    else:
        return False

Note that it will also match Windows Server 2008.