getting argument names from a function

[dan]

def aFunction(arg1, arg2):
   print arg1, arg2

is there a way I can get to the arguments of aFunction (i.e. 'arg1' and 
'arg2')?

I've tried dir(..) on the function object and subsequent object and can't 
find what I'm looking for. Is it possible to do what I want?

thanks,
Dan