This is one of those selfish blog posts I make to remind myself how to do something that I'm bound to forget.
But, if you're using the FreeCAD designer to run Python programs to design robots (as I am) you might find it useful. If you want to be able to print messages from your program onto the report console in FreeCAD you can the following:
App.Console.PrintMessage('hello from the program\n')
For this to work you have to have the output window options in Preferences set to Redirect internal Python output to the report view, but if you do this works a treat. My design programs can now report on progress, which is nice.
Incidentally, I've now got a lot of experience creating solid objects from Python code using FreeCAD. If anyone would like me to do a talk on this, let me know and we can sort this out.