For serious data analysis and CSV manipulation work in Python another library to check out is Tabular:
http://www.parsemydata.com/tabular/
It's built on top of Numpy so it's very fast and plays well with the rest of the Numpy/Scipy ecosystem. I've been using it daily for the last couple of weeks on relatively large data sets (>300MB) and have been very pleased with how elegantly and efficiently it handles things like pivot, join and aggregation.
http://www.parsemydata.com/tabular/
It's built on top of Numpy so it's very fast and plays well with the rest of the Numpy/Scipy ecosystem. I've been using it daily for the last couple of weeks on relatively large data sets (>300MB) and have been very pleased with how elegantly and efficiently it handles things like pivot, join and aggregation.