What behavior would you expect?

[Paul Rubin]

Dan Sommers <dan at tombstonezero.net> writes:
> I'd still prefer an exception to None, and we agree on that an empty
> string is bad because it's not a non-string and it could be too easily
> mistaken for a filename.

Empty string would be bad.  Sometimes I like to simulate an option type,
by returning the value as a 1-element list if there's a value, otherwise
as an empty list.  So you could say

  filename = get_filename(...)[0]

if you want an exception in the failure case, or you could do something
like

  fs = get_filename(...)
  if len(fs) == 0:  ... # didn't get a filename