Voxelize
Rebuild any mesh out of cubes by sampling a volume on a regular grid.
Complete node trees written with nodebpy, each with a render of the result.
Most of these are ports of examples from two earlier projects that also write Geometry Nodes as Python: Geometry Script by Carson Katri and geonodes by Alain Bernard. They are rewritten as nodebpy code rather than translated line for line, so each one also shows how the same idea reads in nodebpy, and each page links back to the original.
Every example is a single script you can run in Blender’s text editor or headless with the bpy module. The script builds the tree and any materials it needs; add the tree to an object as a Geometry Nodes modifier to see the result. The images are rendered by docs/examples/render.py as part of the documentation build.