python write string directly to tarfile

Question

Is there a way to write a string directly to a tarfile? From http://docs.python.org/library/tarfile.html it looks like only files already written to the file system can be a

Answer 1

Just for the record:
StringIO objects have a .len property.
No need to seek(0) and do len(foo.buf)
No need to keep the entire string around to do len() on, or God forbid, do the accounting yourself.

( Maybe it did not at the time the OP was written. )