You must first change the data type used in the attributes to support floating point values
for example: "float"
If I remember correctly, these values are expressed in "long", without this the effect will be only visual.
You'll have fun with the code.
To express a floating point value in python, just use the appropriate representation.
>>> print("%.2f" % val)
About Floating Point Arithmetic (python 2.7)
You should handle it without too much trouble.