This is yet another Inkscape to OpenSCAD export extension (and standalone python-based svg to OpenSCAD converter). Features include:
support for holes (with arbitrary nesting)
ribbons for edges (if colored) and polygons for insides (if colored), either 2D or extruded into the 3rd dimension
optionally produce OpenSCAD code with Bezier splines for my Bezier library
optional smooth 3D inflation of 2D polygons (this is not extrusion: with inflation the edges stay thin and the inside is inflated--see the Bin.stl demo file)
To install, copy the contents of the zip file to your Inkscape share/extensions directory. Restart Inkscape. Load drawing. Make sure that any text is converted to paths in Inkscape (most other drawing commands should work without conversion).
Then Save As... and choose "OpenSCAD path extraction" for ordinary path exports (including 2.5D polygons) and "OpenSCAD inflated file" for inflated files (like the heart example). There are many options to play with. Ask in comments here if any are not clear.