

I will also stay with python 2 for now, but see below for some info on python 3 (see also here for more). However, it is advisable to install a local distribution and do your scientific stuff from there… If you screw something up, you can just delete everything and your OS is safe. Most (if not all) unix systems already come with a python distribution installed.

This is a step-by-step guide to the best way I found to install and use python for science, the easy (less hackable) way comes first, and the long way comes next. All sort of scientific algorithms are already there (written and debugged!), you just have to use them. Python is cool, especially if you a scientist.
