--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/marking2/danube_test4.scala Mon Jan 28 12:49:19 2019 +0000
@@ -0,0 +1,28 @@
+
+// first test
+
+
+def urban_groupById(ratings: List[(String, String)]) =
+ ratings.groupBy(_._1).mapValues(_.map(_._2))
+
+def urban_get_csv_file(name: String) : List[String] = {
+ import io.Source
+ import scala.util._
+ val csv = Source.fromFile(name)
+ csv.mkString.split("\n").toList.drop(1)
+}
+
+def urban_process_ratings(lines: List[String]) : List[(String, String)] = {
+ for (cols <- lines.map(_.split(",").toList);
+ if (cols(2).toFloat >= 4)) yield (cols(0), cols(1))
+}
+
+
+val urban_good_ratings = process_ratings(urban_get_csv_file("ratings.csv"))
+
+val urban_ratings_map = urban_groupById(urban_good_ratings)
+
+assert(favourites(urban_ratings_map, "912").length == 80)
+assert(favourites(urban_ratings_map, "858").length == 158)
+assert(favourites(urban_ratings_map, "260").length == 201)
+