QST: 
### 

- [X] I have searched the [[pandas] tag](https://stackoverflow.com/questions/tagged/pandas) on StackOverflow for similar questions.

- [X] I have asked my usage related question on [StackOverflow](https://stackoverflow.com).


### Link to question on StackOverflow

https://stackoverflow.com/questions/69366483/calculate-percentage-of-occurences-of-a-value-in-a-dataframe-column-based-on-ano

### Question about pandas

**Calculate percentage of occurences of a value in a dataframe column based on another column value.**

So my dataframe looks something like below :

<img width="660" alt="Screenshot 2021-09-28 at 11 27 23 PM" src="https://user-images.githubusercontent.com/1067818/135141118-ef6a9966-0d5f-4c21-a80c-ea080fc42a81.png">

I need to calculate percentage of "contestants" (one of the value in Result column) that are still "operating" (one of the values in OperatingState column). How can derive this in pandas ?

