Function plotter errors: change of python version required?

Hi,

I am trying to plot a function in Inkscape using the function plotter, but it is not working. :(
When I hit apply Inkscape shows the following error:
"Traceback (most recent call last):
  File "funcplot.py", line 34, in <module>
    import simplepath
  File "/usr/share/inkscape/extensions/simplepath.py", line 51
    raise Exception, 'Invalid path data!'
                   ^
SyntaxError: invalid syntax"

To me that looks as if Python 2.x is required . I have both, 2.7 and 3.6 installed. How can I change the python Inkscape uses?

Thank you!