Weighted variance Python script

I need help creating a script in Python that takes 2 inputs, one is a score and the second is a volume. Using this I need to calculate a weighted coefficient of variance.
The data then needs to be rolled up at multiple levels.

As an example column 1 is team name and column 2 is person. A person will appear multiple times in the list so I need a CV weighted for that person, secondly the same weighted for team as multiple people, with different weightings will appear under that team

Examples can be provided to help