Screen flashes at each step

This has always been an issue for me. Each time I step through a line of code, the screen flashes. If the line takes a long time to complete, all I can see is my original prompt (bash or IPython or whatever). This is annoying when stepping through code, because the flashing is disorienting, and it's also annoying when executing a long line of code, because I can no longer see what is executing until it is done. This also happens a lot if there are print statements, as the statement is printed at the "original prompt".

Is this easily fixable, or is it an Urwid issue? I haven't looked at the code yet, but maybe just the screen redrawing commands need to be reorganized a little bit. Can you also reproduce this?