Handling large dense matrices in python

Question

Basically, what is the best way to go about storing and using dense matrices in python?

I have a project that generates similarity metrics between every item in an array

Answer 1

PyTables can handle tables of arbitrary size (Millions of columns!), through using memmap and some clever compression.

Ostensibly, it provides SQL like performance, to python. It will, however, require significant code modifications.

I'm not going to accept this answer until I've done a more thorough vetting, to ensure it can actually do what I want. Or someone provides a better solution.