Did I call PyOne nasty? I didn't know the half of it!

One problem - this module's come from statement doesn't support arbitrary targets; you can only come from a label. This would be much more deadly useful if you could come from anywhere - though I haven't a clue what the syntax for this might look like. comefrom line number?

Additional reading: Go To Statement Considered Harmful, the "first salvo in the structured programming wars", and Goto Considered Harmful - "Twenty rats in a control group were fed a normal diet, while twenty other rats were forced to program in Apple BASIC".