Pandas has a lot of defensive copying. I love Pandas, but I think it demands a lot from the user. When I started using it I was new to traditional coding (i.e.

Pandas has a lot of defensive copying. I love Pandas, but I think it demands a lot from the user. When I started using it I was new to traditional coding (i.e. knowing anything about datastructures), and have come from R. Over time as I've learned a real amount about legitimate data structures, I've become far far better with Pandas.