Changing the Sys.Path for Python Plugins in Gnumeric

[MPJ Grégoire <mpjgregoire theanvil ca>]

I've been writing a Python plugin containing functions for the
structural analysis of beams.  Since each function is rather long and
complicated, I would prefer to use multiple files each containing a
few functions, rather than one file with many functions.  After some
poking at plugin.xml, it seems to me that the simplest way to achieve
my goal is to have plugin.xml refer to wrapper.py, and then use
wrapper.py to import the separate files.

But my import statements don't run correctly in Gnumeric.  While I can
import modules from standard Python locations on the system, files in
the local directory aren't recognised.  This seems to be because the
sys.path doesn't include the local directory.  The obvious solutions
of appending the local directory to sys.path within wrapper.py don't
seem to work either.

How can I change the sys.path settings for Python plugins running
within Gnumeric?

Alternatively, is there a way that I can change plugin.xml so that it
will load functions from multiple Python files?

Many thanks for your help.

Marc Grégoire