Gimp programming : First step with Python-fu

Following my very first attempt in Python programming, the result was a command-line script that get value as arguments and display them as text histogram -  but the real idea behind was to get to know the syntax - Now the real challenge is to program Gimp scripts ... and the attempt below is my very first gimp python script (or python-fu).

It's pretty much the same simple idea to have values represented as horizontal histograms on a picture that can be saved...

Source available at http://pastebin.com/c33zgcSP