I used to run into this problem all the time in grad school. Once a month or so I'd load a data set, do some dumb Python operation on it that took significantly more memory than I predicted, and BAM! I'd have to restart my laptop.

I just kinda assumed that's how computers worked until I got a Mac a couple of months ago...

The link suggests that there might be some default parameters you could change to protect against this behavior. Does anyone have any suggestions on what settings to change?