Principal Component Analysis (PCA) in Python

I have a (26424 x 144) array and I want to perform PCA over it using Python. However, there is no particular place on the web that explains about how to achieve this task (There are some sites which just do PCA according to their own – there is no generalized way of doing so that I can find). Anybody with any sort of help will do great.

scikit-learn DBSCAN memory usage

UPDATED: In the end, the solution I opted to use for clustering my large dataset was one suggested by Anony-Mousse below. That is, using ELKI’s DBSCAN implimentation to do my clustering rather than scikit-learn’s. It can be run from the command line and with proper indexing, performs this task within a few hours. Use the GUI and small sample datasets to work out the options you want to use and then go to town. Worth looking into. Anywho, read on for a description of my original problem and some interesting discussion.