Count items greater than a value in pandas groupby

Question

I have the Yelp dataset and I want to count all reviews which have greater than 3 stars. I get the count of reviews by doing this:

reviews.groupby(\'business         


        

Answer 1

A bit late, but my solution is:

reviews.groupby('business_id').stars.apply(lambda x: len(x[x>3]) )

I came across this thread in search of finding "what is the fraction of values above X in a given GroupBy". Here is the solution if anyone is interested:

reviews.groupby('business_id').stars.apply(lambda x: len(x[x>3])/len(x) )