How I Built a Movie Recommendation System

We are calculating the number of ratings using the count method of a data frame. Using the count method helps count the number of not empty values for each column and returns the result for each column. Sorting by number of ratings, we now see some results. "Star Wars," which is a very famous movie, has got a mean of 4.35 as a rating from 583 users. We are creating a pivot table just to quickly summarize the amount of data we have.