Using broadcast variables to display movie names instead of ID numbers

In this section, we'll figure out how to actually include information about the names of the movies in our MovieLens dataset with our Spark job. We'll include them in such a way that they'll get broadcast out to the entire cluster. I'm going to introduce a concept called broadcast variables to do that. There are a few ways we could go about identifying movie names; the most straightforward method would be to just read in the u.item file to look up what movie ID 50 was, see it means Star Wars, load up a giant table in Python, and reference that when we're printing out the results within our driver program at the end. That'd be fine, but what if our executors actually need access to that information? How do we get that information to the executors? What if one of our mappers, or one of our reduce functions or something, needed access to the movie names? Well, it turns out that Spark will sort of automatically and magically...