Not only do I want to pass the arguments but these are python variables captured with the getvalue() from a Pmw EntryField. Not sure how to refrence the value in Python.
I think I follow you here. This is a simple change to my original args.py where value1,value2 and value3 are possibly set by a call to YourClassInstance.getvalue() - here I've just simply set red,green and blue as examples but it's easy to make the substitutions. Python's string formatting is what you want and here is a simple example.
os.system("./args.sh %s %s %s" % (value1,value2,value3))
The string formatting substitutes value1, value2 and value3 for the string format "%s" specifiers in the string before the "%" operator.