lots of good answers there, and quickly, too! I can see that I need to explain a bit further what I'm up to.
I have a number of variables (environmental variables, actually), most of which will have a value. But some may not have been found by os.environ.get(), so I set those to None. Now, if any of them are None, the app cannot proceed, so I want to test for this and warn the user. I could do something like this (actually, there are more than 3 vars): a = "c:\\programs" b = "d:\\data" c = None (result of an assignment after the os.environ.get() returned a KeyError). if (a is None) or (b is None) or (c is None): #do something here print 'you are missing some env vars' But, that seemed clumsy to me, so I wanted to do something more pythonic, hence my previous post. So, any suggestions? thanks! S -- http://mail.python.org/mailman/listinfo/python-list