This is 20 levels deep. It took a while

OK, I think I got it:

try:
    from drawBot.drawBotDrawingTools import _drawBotDrawingTool
    strokeWidth = _drawBotDrawingTool.strokeWidth
except ImportError:
    print("... must be used either inside RoboFont or inside DrawBot")

I have an external module that can be imported from commandline, or from inside RoboFont, or from inside DrawBot. How can the module detect it’s being imported from DrawBot?

For RoboFont, this works:

try:
    from mojo.drawingTools import *
    inRoboFont = True
except:
    inRoboFont = False

This is 20 levels deep. It took a while