I've got a Python GUI (wxPython) which wraps around a fortran "back-end," using f2py. Sometimes, the fortran process(es) may be quite long running, and we would like to put a progress bar in the GUI to update the progress through the Fortran routine.  Is there any way to get the status/progress of the Fortran routine, without involving file I/O?
At high  risk of being down voted, if you know roughly how long each task is going to take, the simplest option is base the progress on how much time has elapsed since the task started, measured against the expected duration of the task.
To keep it relevant you could always store the run duration for the task each time and use that, or an average, as your base time-line.
Sometimes, we can over over complicate things ;)
Updating long-running Fortran subroutine in Python GUI using f2py