title: Check if input is a list/tuple of strings or a single string
body: <p>I've a method that I want to be able to accept either a single string (a path, but not necessarily one that exists on the machine running the code) or a list/tuple of strings.</p>
  
  <p>Given that strings act as lists of characters, how can I tell which kind the method has received?</p>
  
  <p>I'd like to be able to accept either standard or unicode strings for a single entry, and either lists or tuples for multiple, so isinstance doesn't seem to be the answer unless I'm missing a clever trick with it (like taking advantage of common ancestor classes?).</p>
  
  <p>Python version is 2.5</p>