First of all, there is no point in having a function called division if all it does is print the input.
Now to the actual problem. You are using python 2. In python 2, division of integers is always an integer. So 1/3 (which should be equal to 0.33) is just 0.
The solution is to convert at least one of the numbers to float. This can be done in the following ways:
float(1)/3
1.0/3
And yes, in your current setup, this division will happen before the numbers are passed to your function. So your function works perfectly, it is the input that needs to change.
Edit:
If you cannot alter the input and need to support floating point division of integers use the future module. This brings some of python 3 features to python 2.
Add this line to the beginning of your code:
from __future__ import division