I'm beginner in Python, and calling functions from MATLAB will help me to use functions that don't exist on PYTHON, without having to re-implement them.
Most Matlab functions are actually implemented in Python, it is just a matter of figuring out which package you need. I have found that with the numpy, scipy, and matplotlib packages, I only rarely find myself wanting a Matlab function. Sometimes the function might be called something slightly different.
http://www.numpy.org/
http://matplotlib.org/
http://www.scipy.org/
If you are a student, you can get a free academic license for the Enthought Python Distribution which comes with these packages (and lots, lots more) pre-installed. Highly recommended. https://www.enthought.com/
Python X,Y is similar, less comprehensive, but free to everyone:
You can run Matlab without the GUI via terminal/bash, and probably Windows command-line, though I haven't yet tried that.
Run: matlab -nojvm -nodisplay -r "commands;quit"
You can run shell commands through python. This link will help you do that and process the output: http://stackoverflow.com/questions/89228/calling-an-external-command-in-python
If you have Matlab installed on your computer, above is stable and straightforward. It is also convenient to conversions between Python and Matlab data types.