1 

     2 import CW7b._

     3 

     4 // first test 

     5 

     6 

     7 def urban_groupById(ratings: List[(String, String)]) = 

     8   ratings.groupBy(_._1).view.mapValues(_.map(_._2)).toMap 

     9 

    10 def urban_get_csv_file(name: String) : List[String] = {

    11   import io.Source

    12   import scala.util._

    13   val csv = Source.fromFile(name)

    14   csv.mkString.split("\n").toList.drop(1)

    15 }

    16 

    17 def urban_process_ratings(lines: List[String]) : List[(String, String)] = {

    18   for (cols <- lines.map(_.split(",").toList); 

    19        if (cols(2).toFloat >= 4)) yield (cols(0), cols(1))  

    20 }

    21 

    22 def urban_process_movies(lines: List[String]) : List[(String, String)] = {

    23   for (cols <- lines.map(_.split(",").toList)) yield (cols(0), cols(1))  

    24 }

    25 

    26 

    27 val urban_good_ratings = process_ratings(urban_get_csv_file("ratings.csv"))

    28 val urban_movie_names = process_movies(urban_get_csv_file("movies.csv")).toMap

    29 

    30 val urban_ratings_map = urban_groupById(urban_good_ratings)

    31 

    32 assert((for (n <- List("1", "2", "3", "4", "5")) yield {

    33   recommendations(urban_ratings_map, urban_movie_names, n).length

    34 }) == List(2, 2, 2, 0, 2))

    35