On Sun, 02 Jun 2013 20:16:21 -0400, Jason Swails wrote: > ... If you don't believe me, you've never hit a bug that 'magically' > disappears when you add a debugging print statement ;-). Ah, yes. The Heisenbug. ;-) We used to run into those back in the days of C and assembly language. They're much harder to see in the wild with Python.