Question

我想问一下，如何计算重复值？
格式：USER，ITEM，EVENT
我想算一下，每个项目显示的次数。
以下是一些例子：

US50137,IT1548,7), (US42215,IT6298,7), (US98606,IT5305,7), (US34696,IT5914,7), (US74972,IT2796,7), (US1729,IT7696,7), (US76310,IT9790,7), (US49102,IT6487,7), (US25430,IT7901,7), (US50600,IT4156,7), (US65972,IT9830,7), (US50879,IT1902,7), (US36024,IT6484,7), (US46284,IT3281,7), (US55565,IT5303,7), (US18932,IT2025,7), (US39467,IT8677,7), (US12477,IT9678,7), (US94819,IT8427,7), (US19956,IT1402,7), (US41507,IT3624,7), (US845,IT4823,7), (US18860,IT7860,7), (US68784,IT4759,7), (US79752,IT421,7), (US18563,IT5329,7), (US79628,IT2351,7), (US83729,IT6082,7), (US61097,IT9643,7), (US69368,IT3162,7), (US59566,IT814,7), (US9726,IT7519,7), (US1157,IT5908,7), (US1176,IT3981,7), (US79409,IT8578,7), (US11786,IT5147,7), (US88604,IT8501,7), (US6857,IT2333,7), (US82349,IT6143,7), (US27666,IT9085,7), (US90508,IT352,7), (US48578,IT4503,7), (US14526,IT9551,7), (US29031,IT1992,7), (US57012,IT4353,7), (US97235,IT77,7), (US88666,IT2715,7), (US31035,IT7865,7), (US45054,IT6664,7), (US92069,IT9951,7), (US27175,IT913,7), (US60402,IT8480,7), (US28426,IT9309,7), (US23641,IT4518,7), (US10889,IT7348,7), (US16950,IT6087,7), (US68766,IT683,7), (US87726,IT7594,7), (US63638,IT8101,7), (US78079,IT4344,7), (US47257,IT3315,7), (US3915,IT8971,7), (US59440,IT3441,7), (US64466,IT3980,7), (US79624,IT3502,7), (US29356,IT6778,7)

从这个链接：
Scala how can I count the number of occurrences in a list

我的代码：

val RATING_SPLITER = N1.map(
      {
        baris => (
          baris(0),
          baris(1),
          baris(2) match {
            case "read" => 10
            case "play" => 6
            case "share" => 7
          }
          )
      }
    ).take(1000)
val MM = RATING_SPLITER.groupBy(kk => kk._2).map(x1 => (x1._2))
    MM.foreach(println)

然后，输出如下：

[Lscala.Tuple3;@fd53053
[Lscala.Tuple3;@4527f70a
[Lscala.Tuple3;@707b1a44
[Lscala.Tuple3;@7132a9dc
[Lscala.Tuple3;@57435801
[Lscala.Tuple3;@2da66a44
[Lscala.Tuple3;@527fc8e
[Lscala.Tuple3;@61bfc9bf
[Lscala.Tuple3;@2c7106d9
[Lscala.Tuple3;@329bad59

任何想法，为什么输出看起来像那样？我的代码是否正确计算重复值？

Answer 1

您应该将groupBy生成的值映射到尺寸 - groupBy创建键值对，其中值是具有相同键的所有项的集合，你只对该系列的大小感兴趣：

// sample data:
val RATING_SPLITER = List(("A", "b", 4), ("A", "b", 5), ("A", "c", 6), ("A", "e", 7))

val result: Map[String,Int] = RATING_SPLITER.groupBy(_._2).mapValues(_.size)
result.foreach(println)
// prints:
// (e,1)
// (b,2)
// (c,1)

如何计算scala中的重复值？

1 个答案: