Python Substitute Object

good Morning
Someoneā€¦ Please, Could you help me?
I need A script for substitute object by another object in the scene. How I can do that?
And Is it possibile to make a random distribution an object?
Thanks for any helpā€¦

Blendgraph can swap objects in and out of the scene based upon in image.

The particle system can generate particles from a group randomly.

Check the scripting form, I also wrote a script to distribue objects across the surface of another object, randomly chosing from a group of objects.