#+BEGIN_SRC python :session MYpython :exports results :results file

  #... bunch of matplotlib stuff that produces /tmp/myfig.pdf

  '/tmp/myfig.pdf'

#+END_SRC

This works, and the LaTeX exporter includes /tmp/mfig.pdf:

\includegraphics[width=.9\linewidth]{c:/tmp/myfig.pdf}

My question is, is there any way to remove the width specifier?  If the figure were coming straight from org-mode source text, I could use #+ATTR_LaTeX (well actually maybe not, because there's no way to *remove* the width, but at least I could set it as desired.)  But in the situation above, where the filename is coming from the exporter running the code block, there's no place for me to put the ATTR_LaTeX that works.

Any ideas, exporter gurus?