100GB isn't that big a deal. If you have at least 16GB of RAM it should be a breeze. There are much larger data sets in OpenLDAP in production around the world.

But I wouldn't choose python for large scale data processing work. The python CPU/memory overhead is like 100:1, compared to C. (This is why I worked on rtorrent and ditched the original bittorrent client ASAP, and why I hate bitbake....)