[altairiumblue]

Depending on your use case - numpy, pandas, scipy, matplotlib, statsmodels. Also check out R - you may or may not prefer it to Python, especially if you're coming from Matlab.

[sgillen]

And to add on, octave is a good open source replacement for base matlab with near identical syntax.

[pr07ecH70r]

Thanks a lot! I am more familiar with Python. Never used R before.