I post here the code for histogram using the turtle graphics module, which I posted long time ago in discussion thread. For more special graphs there exist other fancier options, but this tkinter based routine can function in most standard installations of Python.
Example data.txt, like mentioned in module docstring:
Student MarkA MarkB MarkC MarkD MarkF
Alex 5 2 1 0 1
Mark 3 5 1 0 0
Costa 7 4 0 0 3
Rita 0 6 2 2 4
Mary 4 2 3 1 0
John 3 4 2 1 0