Is there a way developed to support the following workflow? I realize this example is trivial but it could be applied to more complex workflows like subgroup moving averages. And while there are ways to run calculations over a DataFrame in a way that does not need the following method sometimes it is easiest (mentally, temporally) to use this sort of brute force approach.

Goal: Number all rows in each group from 1:Number of Rows

Operation 1: Break DataFrame into SubGroups based on Attributes

Operation 2: Add column to each subgroup which numbers it from 1:Number of Rows

Operation 3: Ungroup SubGroups back into single DataFrame

I know Step1 is possible in Julia today. Is there a way to perform operations 2 and 3? I have tried to modify a SubDataFrame and it does not seem possible. Also I canβt find a way to ungroup a grouped dataFrame.