This is really two questions, but they are so similar, and to keep it simple, I figured I\'d just roll them together:
Firstly: Given an est
If using psyco, I'd recommend psyco.profile() instead of psyco.full(). For a larger project it will be smarter about the functions that got optimized and use a ton less memory.
I would also recommend looking at iterators and generators. If your application is using large data sets this will save you many copies of containers.