Evaluating Python not working consistently

[kenny-evitt]

Copied from the original comment on LightTable/LightTable#1641:

Hi there, Evaluating python [on mac osx] has erratic (on my machine at least). It works sometimes (http://pastebin.com/Yzd2xFvy) while it does not work many other times (blocks at the left hand corner just keep rotating) (http://pastebin.com/5Su6dhg3) I will be very thankful to you for your help in resolving this.