DataFrame Operations on Large Frames Seems To Crash Python Kernel on MacOS Yosemite At Random
Apologies for not following the requested format, but there is no output for this error. Running the script from command line will occasionally execute without error, but often python will crash without error. This occurs with both python 3.5 and 2.7, and with pandas 0.18.1 and 0.19.0. 

The code came directly from a windows machine where it ran fine and now it does not run reliably on Mac... In one instance it happens when merging two large frame and in another it occurs when using groupby. 

I know this is extremely obscure but does anyone have any ideas?
