Aggregate Categorical Data I have a scenario in which I'm required to run my analysis at the Account level. One of the features that I'd like to look at is the no. of subscriptions against an account. There can be multiple subscriptions against one account. I wonder how I can "aggregate" these multiple subscriptions and roll them up at the Account level, such that I have a single row for each account.   

I could think of binary encoding but I have 5000 products and that would require creating these many features.
You can use pandas groupby function to group your rows according to  accounts and then perform your desired operation on them.